An optical target system is provided for facilitating a vehicle operator's effecting alignment of the respective hitch assembly components of a towing vehicle and a towed vehicle. The system includes first and second targets that are removably positionable in referencing relationship to respective ones of the hitch assembly components and a viewing mirror that is removably positionable on the towed vehicle to provide the vehicle operator positioned in the towing vehicle with a reflected view of the two targets. Each of the two targets includes a longitudinal guidance element that is disposed in alignment with the longitudinal axis of its respective vehicle and a transverse guidance element that is transversely oriented to the respective longitudinal guidance element and located above the hitch assembly component to provide a visual reference to a vertical axis extending through those components.

Towing vehicles and towed vehicles such as automotive vehicles and trailers are mechanically interconnected by means of a hitch assembly which includes two components that are adapted to be mechanically interconnected, but which may be separated when it is desired to use the automotive vehicle separate and apart from the towed vehicle or trailer. A typical and common arrangement is an automotive vehicle utilized in towing of a recreational or other type of trailer where it is frequently desired to leave the trailer at a fixed location and to then separately use the automotive vehicle. The most usual type of hitch assembly utilized in this specific application is known as the ball and socket type hitch wherein a spherical ball element is mounted on a frame structure secured to the automotive vehicle or towing vehicle and the trailer is provided with a socket adapted to receive the ball and to mechanically secure the ball and socket in mechanical engagement. The particular problem to which this invention is directed is the maneuvering of the towing vehicle with respect to the trailer so as to align the ball and socket along a vertical axis whereby the trailer may be maneuvered to lower the socket onto the ball and effect the interconnection. The automotive vehicle is normally provided with its component of the hitch assembly at the rear with the operator being located a substantial distance forwardly thereof and out of direct visual contact with either that component of the hitch assembly or the socket component carried by the trailer. Consequently, the vehicle operator has substantial difficulty in maneuvering the automotive vehicle so as to effect the alignment of the two components and permit the interconnection.
One technique that is utilized to obtain the alignment of the hitch assembly components is the positioning of an observer at the rear of the automotive vehicle adjacent the front of the trailer who can visually signal the vehicle operator as to lateral and longitudinal displacement to position the ball in alignment with the trailer hitch assembly socket. An observer, however, is not always readily available and thus attempts have been made to facilitate the alignment process through techniques such as use of optical mirrors. An optical mirror system of a very basic form for such purposes is illustrated in U.S. Pat. No. 3,524,701 issued Aug. 18, 1970 to R. J. Stronmeier. That patent merely illustrates a device which includes a convex surface mirror mounted on a vertical standard that may be detachably secured to a component of the trailer at its forward end and to position the mirror at a vertical elevation where the operator of the towing vehicle may look rearwardly and view both the socket on the trailer and the ball coupling on the rear of the towing vehicle. The objective is to enable the operator to ascertain the relative locations of the spherical ball and the receiving socket. While a simple mirror system such as that shown in the noted patent provides a means for the vehicle operator to view the two components of the hitch assembly, such a system fails to provide any guidance information as to the direction of movement of the ball on the towing vehicle with respect to the trailer hitch socket. Alignment of the two components requires that the vehicle operator be aware of the direction of movement of the ball along a path that is related to the longitudinal axis of the vehicle. The disadvantage of simply using a mirror is that the vehicle operator is not apprised of the longitudinal axis along which the ball joint is traversing even though the vehicle operator may have a general view as to the orientation of the towing vehicle with respect to the trailer. Consequently, a slight angular differentiation as between the longitudinal axis of the towing vehicle as to the towed or trailer can result in a misalignment of the two components, and thus, necessitate a second attempt, or more, to effect the proper alignment.
Another significant deficiency of a simple mirror system such as that shown in the Strohmeier patent is the relative inability of such a structure to be readily adapted to the wide range of dimensional variations as between various models and manufacturers of trailers since the location of the front support jack assembly may be located at several diverse positions with respect to the hitch assembly socket. Strohmeier has attempted to solve that problem through suggesting that the support standard for the mirror be made of a material that permits it to be bent to different shapes so as to locate the mirror at different positions. However, the bending of a support standard necessarily is limited in its capability to properly locate the mirror as to any particular trailer and hitch assembly. Also, mounting of the support standard by means of a simple magnetic attachment to the post of the front support screw jack does not provide a great amount of versatility in appropriately locating the mirror at a proper elevation with respect to the different types of automotive vehicles. For example, bending the support standard so that it will locate the mirror in a more forward direction with respect to the jack stand necessarily results in placing the mirror at a lower elevation and that may significantly alter the viewing angle with respect to the vehicle operator for his particular vehicle and may adversely affect his ability to view the two hitch assembly components.

Optical target system for trailer hitch alignment


An adaptor, a light source device using the adaptor, and a lighting apparatus using the adaptor are provided. The adaptor includes a main body, a protruding part, and an operating component. The main body includes: a power supply mounting part, a light source mounting part, and a conducting circuit extending from the power supply mounting part to the light source mounting part; the protruding part is operatively movable to a blocking position for blocking the power supply mounting part from being engaged with the power supply module, and a releasing position for releasing the power supply mounting part to be engaged with the power supply module. The operating component is operatively movable on the main body to an on-position and an off-position.

At present, a lighting apparatus usually emits irradiation light towards an irradiated object by an electrically driven lighting module so as to achieve illuminating the irradiated object. With the rapid development of the lighting technology, the lighting apparatus is becoming more and more popular, and how to improve a safety of the lighting apparatus has received attentions in the industry.
An existing lighting apparatus generally includes a light-emitting apparatus for emitting irradiation light, a power supply module for supplying an electric power, and an adaptor for engaging the light-emitting apparatus with the power supply module. The adaptor typically includes: a conducting circuit for connecting to the light-emitting apparatus, and a conducting terminal which is electrically connected to the conducting circuit and is used for engaging with the power supply module. After the light-emitting apparatus, the adaptor and the power supply module are connected, the electric power outputted by the power supply module passes through the conducting terminal and the conducting circuit in sequence, and then arrives at the light-emitting apparatus to allow the light-emitting apparatus to emit the irradiation light.
However, the existing lighting apparatus is not provided with any safety protection device. A user can directly electrically connect the conducting terminal with the power supply module to activate the lighting apparatus. When the conducting terminal is electrically connected with the power supply module due to a misoperation of the user, the user is likely to be subjected to an electric shock, leading to a severe safety risk in the existing lighting apparatus.

This patent is subject to a terminal disclaimer.

Adaptor, light source device, and lighting apparatus


A plurality of data packets encoded according to a first protocol are received which encapsulate data encoded according to a second protocol. A first source address is extracted from the packets according to the first protocol, it is determined whether or not the first source address is a substantial duplicate of a known assigned address. If it is a duplicate, a second source address is extracted from the encapsulated data according to the second protocol, and the first source address and said second source address are provided in an enhanced error log so that a system administrator may correct the duplicate assigned address. Enhanced embodiments of the invention included analysis of data encapsulated by a third, fourth and subsequent protocols, and automatic determination of each protocol encoding format.

1. Field of the Invention
The present invention relates to technologies for managing assignable network addresses to devices and adapters in computer and data communications networks, and especially to methods and processes for detecting duplicate network addresses.
2. Background of the Invention
FIG. 1 shows a typical example of a computer communications network or data communications network (11), which interconnects a number of network devices ND1, ND2, . . . NDM, . . . NDN, . . . NDP, NDP+1 . . . NDQ (17, 18, 19, 12, 103, 104, 105, 106). Certain portions of the total network (10) may be isolated or partitioned into subnetworks ("subnets") (15, 101, 102) by devices such as switches, bridges, and routers (14, 100, 103), while other devices such as NDN (12) may be directly connected to a larger or central portion (11) of the network (10).
In a computer communications networks, each device connected to the network (e.g. a "network adapter") typically has its own, unique low level address, such as a manufacturer assigned Media Access Control Address ("MAC") in the case of an Ethernet network. A network adapter's address is used to uniquely identify the adapter in the network when sending it data, or when receiving data from it. In a healthy network, no two adapters have the same address. Data is typically transmitted in such networks in small bursts, often referred to as packets, frames, or cells, depending on the network origins and terminology.
However, most network adapters also provide a software-definable address which overrides or replaces the manufacturer-supplied address. These "soft" addresses are often used by systems to reorganize or optimize the addressing scheme within a local area network ("LAN"), or within a wide area network ("WAN"). Such software defined addresses are referred to as Locally Administered Addresses ("LAA") in the Ethernet paradigm.
Care must be taken when assigning soft addresses to avoid assigning an address which is the same as the address of another network adapter on the same network. An invalid address will cause networking problems, especially in the case when the invalid address is a duplicate of another address on the same subnet.
Most data network protocols, such as Ethernet, provide some sort of fundamental process or mechanism to detect duplicate addresses, and in some cases, reassign them. Ethernet's Address Resolution Protocol ("ARP"), and Internet Protocol's ("IP") Duplicate Address Detection ("DAD") processes are two such mechanisms. FIG. 2 generally illustrates a relatively simple process (30) employed by many protocols to detect duplicate addresses, in which a unit receives (31) a frame or packet, extracts the sending unit's address (32), determines if it appears to be a duplicate address (33), and if so, simply reports (35) the duplicate address value (36) to an error log. At this point, it is up to the administrator to try to determine from only this information which unit or units are improperly using the same network address. If the sending unit address does not appear to be a duplicate address, the frame or packet is handled normally (34) (e.g. terminated, delivered, routed, switched, etc.).
The typical logic in LAN adapters today only reports a duplicate network address, usually through event interrupt to a host processor when a network adapter receives a message or packet from two sources which claim to have the same return address (e.g. source address). This logic typically does not give any more detail data, as the protocol does not readily provide any other diagnostic information which the logic can easily report. IP DAD is well known to perform poorly in the presence of partitions, and because of its dependence on the use of timeouts, can be error prone in network where entry and exit of devices is expected often.
When a duplicate address is detected by Ethernet ARP, message "storms" can create excessive LAN traffic to duplicate MAC addresses. In addition, Ethernet switches can be adversely affected (ports taken out of services) and packets can be incorrectly routed. Ethernet LAA and similar redefinable address capabilities in other network types create a much higher possibility of assigning duplicate network addresses, which often creates many network problems.
With no additional data on which to operate, there is no easy way for a system administrator to determine which network adapters in which network-attached systems are sharing duplicate addresses.
This problem is exasperated by newer networks which "auto-configure"; i.e. each network adapter is automatically assigned an address upon entry or connection to the network. Many wired and wireless network protocols include auto-configuration processes, some of which include use of an address server (16, 13). For example, in Internet Protocol, dynamic host address assignment is provided in many cases by Dynamic Host Configuration Protocol ("DHCP"), which requires access to a DHCP server to act as a centralized arbitrator and controller of addresses. However, there are many situations in which access to a centralized server is intermittent or unavailable, such as certain types of wireless networks and especially small networks.
One alternative which has reportedly been proposed for systems which use large IP address values has been to somehow embed the Ethernet MAC address of a device into the dynamically assigned IP address, assuming that the MAC address is unique. But, in some cases, this is not feasible, such as attempting to embed a 48-bit IEEE 802.11 MAC address into a 32-bit IP (Version 4) address.
Another proposed solution is to issue some sort of message on a network which uses a potential address for assignment to see if a response is received from another adapter already having that address. In order to complete this process, a time limit must be assumed, after which if no response has been received, it is assumed that the potential address is free to be assigned to a newly attached or connected device. However, in some networks where large, unbounded delays are possible such as systems with many partitions, selection of an appropriately long time out value may not be possible, thereby rendering the method inoperable or impractically slow in some situations.

International Business Machines Corporation


The present invention relates to composite structural members comprising polymers, natural and synthetic fibers, and nano-scale platelets arranged in two- or three-dimensional cellular skeletal structure; more particularly referring to a low-cost natural-fiber based structural member with material hybridization and material layout for improved behavior that leads to efficient structural beam and plate/panel components that can be used in a plurality of modular structures, resulting in lower cost and reduced environmental impact.

(1) Field of the Invention
The present invention relates to composite structural members comprising polymers, natural and synthetic fibers, and preferably nano-scale platelets, arranged in two- or three-dimensional cellular skeletal structure; more particularly referring to a low-cost natural-fiber based structural member with material hybridization and material layout for improved behavior that leads to efficient structural beam and plate/panel components that can be used in a plurality of modular structures, resulting in lower cost and reduced environmental impact.
(2) Background of the Invention
Fiber reinforced polymer (FRP) composites have surpassed their initial target applications in the aerospace industry to become a viable material alternative in the sporting goods, automotive, and construction industries. High performance FRP composites made with synthetic fibers such as carbon, glass or aramid embedded in polymeric matrices provide the advantages of high stiffness and strength to weight ratio and increased chemical inertness compared to conventional construction materials, i.e., wood, clay, concrete and steel. In spite of these advantages, the widespread use of synthetic FRP composites has been limited, among several factors, due to their higher initial material costs, their use in non-efficient structural forms and their environmental impact.
Increased environmental awareness and the interest in long-term sustainability of construction materials have thus challenged the development of environmentally friendlier alternatives to synthetic oil-based FRP composites (Mohanty et al. Macromol Mater Eng, Vol. 276/277, 1-24 (2000)). Natural-fiber-reinforced polymer composites, or biocomposites, have emerged in the past decade as an environmentally friendly and cost-effective option to synthetic FRP composites. Despite the interest and environmental appeal of biocomposites, their use has been limited to non-primary, or non-load-bearing applications due to their lower strength and stiffness compared with synthetic FRP composites (Biswas et al., "Development of Natural Fibre Composites in India", Proceedings of the Composites Fabricators Association's Composites, Tampa, Fla. (2001)). Recent developments, however, have shown that the properties of "engineered" biocomposites (Mohanty et al., "Surface modifications of Natural Fibers and performance of the Resulting Biocomposites: An Overview," Composite Interfaces, 8, 313-343 (2001); and Mishra et al., Mishra, S., et al., Composite Science and Technology 63 1377-1385 (2003)) are a technical, economical, and environmentally conscious alternative to E-glass fiber reinforced composites (the most common synthetic fiber composite) without sacrificing performance.
While biocomposite materials with specific properties equivalent to entry-level structural materials are feasible, this performance level is still not enough to make them able to compete with existing construction materials. However, the structural performance of a component depends on both its material and structural properties. The lower material stiffness of biocomposites can thus be overcome by using efficient structural configurations that place the material in specific locations for highest structural efficiency. Cellular and sandwich structures are structural configurations that yield high structural performance for minimum material use and thus minimum weight (Gibson, et al., Cellular Solids: Structure and Properties. Pergamon Press, Oxford (1988)). This concept has been recognized for some time and has recently gained new attention due to the way that natures own materials and structures follow these principles.
Natural fibers embedded in a natural or synthetic polymeric matrix, known as biocomposites, have gained recent interest because of their low material and manufacturing costs, light weight, high specific modulus (elastic modulus over density), and environmentally friendly appeal (Mohanty et al., Macromol Mater Eng, Vol. 276/277, 1-24 (2000)). Natural fibers are categorized depending on their source as either leaf or bast fibers. Bast fibers have the highest mechanical properties and thus are ones typically considered for structural applications. The most common bast fibers are flax, hemp, jute, and kenaf. Typical mechanical properties of these fibers together with E-glass fibers are given in Table 1. All natural fibers are lingo-cellulosic in nature with the basic components being cellulose and lignin. The density of natural fibers is about half that of E-glass (Table 1), which makes their specific strength quite comparable, while the elastic modulus and specific modulus is comparable or even superior to E-glass fibers.
TABLE 1Mechanical Properties for Selected Natural Fibers and E-Glass FiberElasticTensileSpecificSpecificFiberDensityModulusStrengthModulusStrengthType(g/cm3)(GPa)(MPa)(GPa/g/cm3)(MPa/g/cm3)E-glass2.55732000–350029 780–1370Hemp1.487069047466Flax1.460–80 345–110043–57250–785Jute1.4610–30400–750 7–21275–510Sisal1.3338450–64029340–480
The applications for which biocomposites have been studied include interior paneling of automobiles (Biswas et al., Proceedings of the International Conference and Exhibition on Reinforced Plastics, Indian Institute of Technology, Madras, 26-36 (2002)) and replacement of wood in housing applications such as plywood, roof surface paneling, partitioning and furniture (Biswas et al. Proceedings of the Composites Fabricators Association's Composites, Tampa, Fla. (2001)). The current market uses of natural fiber composites in North America are shown in FIG. 1 (Mohanty et al., Macromol Mater Eng, Vol. 276/277, 1-24 (2000)). However, the uses in these markets have been limited to non-structural applications where weight and cost can be reduced (Biswas et al., Proceedings of the Composites Fabricators Association's Composites, Tampa, Fla. (2001)).
Consideration of biocomposites for load-bearing, or structural applications has been neglected due to their low stiffness and strength in comparison with conventional construction materials, and only limited research and development projects have considered potential structural uses (Scott, C. T., et al., Wood and Fiber Science, 27(4): 402-412, (October 1995); and Shenton III, H. W., et al., "Manufacture of Fiber-Reinforced-Foam Composite Sandwich Structures", Proceedings of the International Conference on Advances in Building Technology, Hong Kong, China (December 2002)). However, recent research on biocomposites has shown that "engineered," or treated, natural fibers can lead to biocomposites with properties that can compete with glass fiber composites (see FIG. 2). This has motivated further research initiatives that consider biocomposites as a technical and environmentally conscious alternative to E-glass reinforced fiber composite (the most common synthetic fiber composite) without sacrificing performance. Natural fiber unsaturated polyester composites show lower density, equal flexural modulus, comparable flexural strength but relatively poor impact strength as compared to a glass fiber composite as shown in FIG. 2 (Mishra et al., Polymer Composites, 23, 164-170 (2002), Mohanty et al., Journal of Polymers and the Environment, Vol. 10, Nos. 1/2, (April 2002)).
Increased environmental awareness and interest in long-term sustainability of material resources has motivated considerable advancements in composite materials made from natural fibers and resins. Natural and wood fiber plastic composites are among the most rapidly growing markets within the plastics industry. Applications for these composites range from building products, automotive, and consumer/industrial applications. However, despite the developments on biocomposites technology and the many applications thus far, their lower stiffness and strength properties have limited their applications to non-load-bearing components. Technical developments on natural fiber-reinforced composites, or biocomposites, have shown that they are a technical, economical, and environmentally conscious alternative to E-glass fiber reinforced composites (the most common synthetic fiber composite) without sacrificing performance. In spite of these achievements, biocomposites are hindered by the hydrophilic nature of the natural fibers and the heat susceptibility of the polymer matrix. In addition, while the properties of biocomposites can compete with those of E-glass composites, their strength, and particularly stiffness, is smaller than that of conventional structural materials.
Development in biobased polymers in our group has shown that blending of functionalized soybean oil with petro-based resins can increase the toughness of a petroleum-based thermoset resin without compromising stiffness and improving its environmental friendliness (Belcher, L., Polymeric Materials Science and Engineering, American Chemical Society, 87, 256-257 (2002)). Emerging research on layered silicate polymer composites, consisting of nano-clay sheets within a polymer, have shown that a small amount (˜1-2%) of nano-scale layered silicate particles can significantly enhance and stabilize the mechanical and thermal properties of the base polymer and improve its fire retardancy (Garcés, J. M., et al., Advanced Materials, Vol. 12, no. 23, pp. 1835-1839 (2000); and Vaia, R., "Polymer Nanocomposites open a New dimension for Plastics and Composites," The AMTIAC Newsletter, Vol. 6, No. 1) without sacrificing viscosity. The true value of layered silicate composites is not solely the enhancement of the neat resin but rather the value-added properties it provides to the fiber-reinforced composite. Thus, natural fibers must remain as the predominant reinforcement for providing stiffness and strength. Finally, scrutiny of nature's materials shows that high structural efficiency can be achieved by optimized hybrid designs that efficiently combine constituents and material arrangement, or shapes, that maximize performance with as little material as possible, i.e., sandwich structures (Gunderson, S. L., et al., "Natural Cellular and Sandwich Structures for Innovative Design Concepts," Proceedings of the ASC 8th Annual Technical Conference, Cleveland, Ohio, 431-440 (19-21 Oct. 1993); and Nogata, F., "Learning About Design Concepts From Natural Functionally Graded Materials," Composites and Functionally Graded Materials, ASME, MD, 80,Dallas, Tex., 11-18 (1997)).
The invention thus focuses on natural-based composites, or biocomposites, that can serve as a sustainable alternative to synthetic load-bearing panels by designing them and manufacturing them in novel sandwich structures obtained from optimized hybrid designs that encompass material constituents, shape and scale effects.
Hybrid biocomposite cellular structures can be used in multi applications (e.g., building walls, floors and roofs, bridge and ship decks, aircraft floors) with tailorable integrated multi-functions (i.e., stiffness, strength, thermal insulation, fire protection, and user friendliness). The sustainability and social acceptance of the proposed components, stemming from its large constituency on rapidly renewable resources, will pioneer the use of agricultural commodities in markets aimed at load-bearing materials and structures.

Hybrid natural-fiber composites with cellular skeletal structures

Board of Trustees of Michigan State University


An uninterruptible power supply having an input connector for receiving AC power from a centralized source of electric power such as a power grid of an electric utility company, a first electric outlet, and a second electric outlet for delivering AC power, a first switch for selectively allowing AC power therethrough to the first outlet, a second switch for selectively allowing AC power therethrough to the second outlet: and a controller operable to control the second switch so that AC power is delivered to the second outlet a predetermined amount of time after AC power is delivered to the first outlet (i.e., after a time delay).

The present invention relates to uninterruptible power supplies used to supply power to electronic equipment, such as computers, communication devices, and the like.
Uninterruptible power supplies are designed to provide power to electrical and electronic equipment during power failures and, in many instances, to protect such equipment from fluctuations (such as under- and over-voltages) in power provided to them. In the specific case of a power failure (meaning the loss of electrical power from an electric utility company or other large scale provider of electricity) an uninterruptible power supply ("UPS") supplies power from one or more integrated batteries to the equipment connected to the UPS. Upon return of power from the electric utility company, the UPS generally returns to normal operation by supplying or relaying power from the utility company to the equipment connected to the UPS and recharging the batteries.


A signal configuration method, device and storage medium are provided. The method includes: acquiring at least one type of reference information, wherein the reference information is used to characterize a configuration status of a communication network; and configuring time domain and/or frequency domain resources for a phase-tracking reference signal based on the at least one type of reference information, and obtaining configuration information of the time domain and/or frequency domain resources for the phase-tracking reference signal, wherein the configuration information includes a density or a pattern corresponding to the time domain and/or frequency domain resources.

A 5G (Fifth Generation) New Radio (NR) will support full frequency-band access covering both a low frequency band (less than 6 GHz) and a high frequency band (6 GHz to 100 GHz). The high frequency band has a serious problem of phase noise, which is caused by non-ideality of a local oscillator. Compared with a communication system utilizing the lower frequency band less than 6 GHz, a communication system utilizing the higher frequency band from 6 GHz to 100 GHz experiences a significant increase in the phase noise due to a substantial increase of the order of frequency multiplication of a reference clock source. The phase noise degrades a Signal Noise Ratio (SNR) or an Error Vector Magnitude (EVM) at a receiving end and leads to a lot of bit errors, thereby limiting directly a usage of high-order constellation modulation schemes and putting a serious impact on a system capacity.
At present, a phase-tracking reference signal is configured with fixed consecutive resources in a time domain and a fixed density in a frequency domain. Although the phase-tracking reference signal configured in this fixed manner exhibits excellent phase-tracking performance, an overhead of the reference signal is extensive due to consecution of the resources in the time domain and fixity of the density in the frequency domain, therefore leading to a poor spectrum efficiency.

Signal configuration method, device and storage medium

China Mobile Communication Ltd., Research Institute

China Mobile Communications Group Co., Ltd.


An improved electrical sensing zone apparatus and method for counting and measuring size of particles suspended in a diluted electrolytic solution. The apparatus includes an aperture that is optimized with the use of double or single tapered shapes that approximate a hyperboloid of one sheet. The flow rate is selectably controlled to maintain a sufficiently low Reynolds number to avoid boundary layer separation effects that cause noise and consequently low sensitivity. By measuring statistical moments within the aperture, an approximation of the distribution of particle sizes is achieved.

1. Field of the Invention
The present invention relates to a method and apparatus for size measurement of particles.
2. Description of the Related Art
Determining the number and size of particles suspended in a liquid solution is important for many industries. Medical applications, such as blood cell counters, have evolved from Coulter's seminal invention, U.S. Pat. No. 2,656,508 issued on Oct. 20, 1953. The preferred embodiment shown in FIGS. 1 and 6 of Coulter's patent was the beginning of what are today generically referred to as "electrical sensing zone" (ESZ) devices or methods. In an ESZ device a particle is measured by passing it through an electrical current-carrying aperture in an insulating partition between two containers, holding a conductive liquid. The motion of the particle through the aperture is caused by a pressure difference across the partition produced by a vacuum or pressure source. The presence of a particle in the aperture increases the electrical resistance of the aperture by displacing the liquid of equal volume to the particle volume. The physical chemistry of particles immersed in an electrolytic solution causes all particles (even those that are electrically conducting) to behave as if they were electrical insulators. The change in resistance may be detected as an increase in voltage across the aperture, or a decrease in current through the aperture. The change in resistance is approximately proportional to the volume of the particle. It is this approximate relationship between aperture resistance change and particle volume that gives the ESZ method good accuracy compared to several other methods of particle size measurement. On the other hand, the ESZ method has comparatively low sensitivity to submicrometer particles due to a multiplicity of noise sources in the aperture, comprising thermal noise due to aperture resistance, noise due to turbulence caused by electrical heating of the liquid in the aperture, noise due to hydrodynamic turbulence caused by flow of liquid through the aperture, noise caused by acoustic interference, noise caused by electrical interference and noise caused by mechanical vibrations. The deleterious effects of noise in the ESZ instrument are magnified by the fact that a signal pulse created by the passing of a particle through the aperture must exceed a predetermined threshold voltage in order to be detected. The threshold voltage must be set high enough so that the peaks of the noise will not falsely trigger the threshold circuit enough times to substantially interfere with the true pulses generated by the particles. The peak of the random noise is several times the root mean square (r.m.s.) level, and this requires the threshold voltage to be set a multiple number of times higher than the r.m.s. noise level. This causes a loss in sensitivity.
The usual aperture shape used in commercial prior art ESZ instruments is the circular cylinder. Until now, this has been considered to be the optimum aperture shape for the highest sensitivity. The circular, cylindrical, aperture shape causes pulses due to particles to have a wide variety of shapes. A pulse due to a particle passing along the axis of the aperture has a single peak. Other particle paths can have pulses with dual peaks, because at both the entrance and the exit of the aperture, the electric field intensity is higher at the edges than at the center. The variations in pulse shapes make it necessary to have a wide bandwidth pulse amplifier so that the pulses would be reproduced by the amplifier with high fidelity. The wide bandwidth increases the noise level. The thickness of the insulating partition through which the aperture is bored must be at least 30 micrometers (μm), the length-to-diameter ratio of the aperture is large, and this results in poor sensitivity. This is because the internal volume of the aperture must be small for high sensitivity, and a large thickness of the partition makes the aperture length long, which makes the aperture volume large.
The circular, cylindrical, aperture causes boundary-layer separation of the liquid therein. The boundary-layer separation produces noise due to turbulence. At the input of the aperture, there is a hydrodynamic constriction of the fluid flow diameter. At the output of the aperture, there is a jet oriented along the axis that is surrounded by backflow of toroidal shape. Some of the particles that have passed through the aperture are captured by the backflow and recirculate near the exit of the aperture, and this causes noise in the form of false particle pulses.
The measurement range, or "dynamic range" of an aperture is limited to about 20/1 in particle diameter, making the ESZ instrument useful for relatively narrow particle size distributions.
Most particle size analysis done with the ESZ instrument is done with apertures 30 μm in diameter, or larger. Apertures smaller in diameter have been available commercially for prior art instruments, but these smaller apertures have been little used because of their tendency to be plugged by debris. If the aperture is plugged, the instrument cannot continue to measure particles until the plug is dislodged.
Even if debris does not cause plugging, it can cause particles to be measured that are not part of the sample being tested. To keep debris from interfering with the sample, the sample concentration must be significantly higher than the debris concentration. But the sample concentration must be low enough to avoid multiple sample particles from being simultaneously in the aperture. This is called "coincidence." Coincidence of particles in the aperture can cause errors in the measured particle size distribution.
U.S. Pat. No. 3,742,348 issued on Jun. 26, 1973 to Golibersuch, addresses the problems related to plugging by debris, coincidence, and low sensitivity to small particles, by allowing a multitude of particles to pass though the aperture simultaneously. This allows a larger diameter aperture to be used than is needed to detect single particles, thus reducing the frequency of plugging. Also, smaller particles can be detected than by a single-particle measurement. One of the disadvantages of this invention is that the circular, cylindrical, aperture requires a large length-to-diameter ratio (on the order of 20/1) in order to get a signal that can be analyzed by the signal processor proposed by the inventor. The only information it obtains is equivalent to what I call "λ2" in a subsequent section of this specification, for the special case where all of the particles in the sample have equal volumes. It will be apparent that μ2, by itself, is not a significant amount of information about the particle size distribution. Also, assuming all of the particles to be the same size is a very unrealistic and restrictive assumption.
Applicant believes that the closest reference corresponds to U.S. Pat. No. 4,926,114 issued to Doutre on May 15, 1990 for an apparatus for studying particles having an aperture whose cross-sectional area changes progressively along at least part of its length. Doutre's patent discloses an apparatus and method for studying particles suspended in molten metal that includes an aperture with a current path therethrough, causing the fluid to flow through the aperture and detecting resistive pulses caused by the passage of suspended particles. An aperture with a cross-section that changes progressively along its length provides additional information about particle size. However, it differs from the present invention because it has the same sensitivity limitations of the other prior art devices since it does not keep the Reynold's number of the fluid flow within the required range to minimize or preclude boundary layer separation effects. Doutre's patent is not even concerned with these effects since it applies to molten metals. In fact, Doutre's invention is intended for use with apertures that ideally contain no more than one particle at a time. Col. 4, lines 51-53. There is not even a suggestion of using statistical moments to make inferences about the size of the particles.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.

Method and apparatus for particle counting and size measurement


A process for growing a single crystal comprises providing a single crystal substrate acting as a seed crystal above a source material in a container, heating the source material in an inert gas atmosphere in the container to form a sublimed source material, and discharging the sublimed source material from the container through a port above the single crystal substrate, to cause the sublimed source material to flow along and in parallel with a surface of the single crystal substrate, and grow a single crystal on the surface of the single crystal substrate.

1. Field of the Invention
The present invention relates to a process and apparatus for growing a single crystal of, e.g. silicon carbide by the subliming recrystallization method, particularly a process and apparatus for growing an excellent single crystal with fewer defects.
2. Description of the Related Art
Conventionally, silicon carbide single crystal substrates are prepared as semiconductor substrates for high voltage high power semiconductor devices such as high voltage power transistors and high voltage diodes. The known methods for the manufacture of the silicon carbide single crystal substrates include the Acheson method, the Ley method and the subliming recrystallization method (Modified Lely method). The subliming recrystallization method is often adopted, for preparing semiconductor substrates, since it is advantageous for growing large area and high quality silicon carbide single crystals.
The subliming recrystallization method is disclosed in Japanese Examined Patent Publication (Kokoku) No. 63-57400.
Referring to FIG. 1, a silicon carbide powder 2 is charged in a closed carbide crucible 1 and heated and sublimed by an induction coil 8. A silicon carbide seed crystal 3, made of silicon carbide single crystal, is located in the crucible to face the silicon carbide powder 2. From the sublimed silicon carbide, silicon carbide 4 grows on the surface of a silicon carbide seed crystal 3 made of silicon carbide single crystal. The thus prepared silicon carbide single crystal 4 is supplied as a semiconductor substrate having a large area, controlled in its crystallinity and suitable for use in manufacturing a semiconductor device.
Optionally, liquid phase epitaxy (LPE) or vapor phase epitaxy (CVD) is further applied to the above silicon carbide single crystal substrate to form on the substrate a silicon carbide single crystal layer different in conductivity-type or carrier concentration from that of the substrate, which is also supplied as a substrate for manufacture of a semiconductor device.
However, a single crystal silicon carbide prepared by the above preparing method may have a number of linear defects, called micropipe defects, penetrating through the substrate. The micropipe defects involve electrical conductivity and therefore semiconductor devices manufactured using this semiconductor substrate with the micropipe defects may have defects such as leakage between source and drain or between gate and drain, which was confirmed by experiment
To prevent the problems due to micropipe defects, Japanese Unexamined Patent Publication (Kokai) No. 5-262599 proposed use of a crystal plane perpendicular to (0001) plane as the surface of a silicon carbide single crystal substrate in the subliming recrystallization method.
However, since this method uses crystal growth in the direction perpendicular to (0001) plane, this method cannot be used for semiconductor substrates having (0001) plane as the surface thereof. For example, when the semiconductor device to be manufactured is a vertical-type MOSFET, a semiconductor substrate having a surface of (0001) plane is usually used and the above method cannot be used.
The object of the present invention is to provide a process and apparatus for growing a single crystal substrate of, e.g., silicon carbide, in a large scale while micropipe defects are prevented.


Apparatus for dispensing liquid through a plurality of tubes. A valve is provided to interrupt flow of the liquid to the plurality of tubes which tubes thereafter retain any undispensed liquid contained therein due to capillarity caused by surface tension between any retained liquid and the internal walls of the plurality of tubes.

This invention relates generally to apparatus for dispensing liquid and more particularly relates to apparatus for dispensing pressurized liquid with improved liquid retention for preventing unwanted liquid dispensing.
Numerous apparatus for dispensing liquid are known to the prior art. For example, and not by way of limitation, the typical blow-fill-seal machine known to the prior art includes apparatus for dispensing liquid into a partially formed plastic container, produced by blow molding, after which the container is sealed to provide what is typically referred to in the art as a pre-filled container. Such apparatus for dispensing liquid typically includes a single, hollow, elongated, cylindrical tube through which the liquid is dispensed into the partially formed plastic container; the single, hollow, elongated, cylindrical tube is typically referred to in the art as a fill needle. Upon cessation of such liquid dispensing, typically produced by valve action, liquid is retained in the fill needle by capillarity caused by surface tension between the retained liquid and the internal wall of the fill needle. Since the blow-fill-seal machine includes moving parts, vibration can be experienced which is sufficient to disrupt or overcome the surface tension between the retained liquid and the internal wall of the fill-needle causing highly undesirable over filling of the container and/or mess or liquid spillage which can be sufficient to require operation of the blow-fill-seal machine to be stopped for cleaning. Continuous operation of the blow-fill-seal machine is highly desirable for increased productivity with attendant production cost decrease while such machine stoppage is highly undesirable due to reduced productivity with attendant increase of production cost.
Accordingly, there is a need in the art for apparatus for dispensing liquid with improved liquid retention which, by way of example and not by way of limitation, is particularly useful with the above-noted blow-fill-seal machines.

Apparatus for dispensing liquid with liquid retention


A method for cleanly extracting metallic silver includes: mixing an acidic solution containing Ce4+ and NO3− with a silver-containing material for leaching; after the leaching is completed, carrying out a solid-liquid separation to obtain a leaching solution containing Ce3+ and Ag+; and electrolyzing the leaching solution, wherein an oxidation reaction of Ce3+ occurs at an anode to realize a regeneration of Ce4+ and an electrolytic reduction occurs at a cathode to reduce Ag+ to obtain the metallic silver. Ce4+ is used as a leaching agent and an intermediate oxidant to implement a cyclic operation of solution leaching and electrolytic regeneration on the silver-containing material. Almost no NOx and waste liquid are caused by the extraction process, and the invention is clean and environmentally friendly.

Silver is an important catalytic material and can be used as an active ingredient in various oxidation catalysts. Also, silver is the most conductive metal and can be made into wires, foils, coatings or electroconduction slurry. Silver has become an indispensable raw material in modern industry with global consumption reaching 31,000 tons in 2014. As silver is a precious metal, the recovery of silver has significant economic value.
Due to the high solubility of silver nitrate in water, silver is generally leached by nitric acid, then silver is precipitated and separated from other metals by using chloride ions as a precipitant, and then silver chloride is reduced by a reductant to obtain metallic silver. For example, Sun P-P (Recovery of Silver from the Nitrate Leaching Solution of the Spent Ag/α-Al2O3Catalyst by Solvent Extraction, Industrial & Engineering Chemistry Research, 2014) uses nitric acid to leach silver from a spent Ag/α-Al2O3 catalyst. This research shows that when the concentration of HNO3 is greater than 1 mol/L, the product of the reaction between silver and HNO3 is NO2 and when the concentration of HNO3 is less than 1 mol/L, the reduction product is NO. After grinding the spent silver-containing catalyst, the researchers used 1 mol/L of dilute nitric acid for a reaction at 70° C. for 2 hours. The final silver leaching rate reached 95%.
The existing common problems of this method are as follows. 1) The reaction of nitric acid with silver will generate a large amount of nitrogen oxide gas; 2) Nitric acid, chlorides, reductants, NOx exhaust gas absorbents, and other reagents are used in the reaction process, which is not only costly, but also causes a large amount of waste liquid.
To solve the above problems, some researchers have tried to recover metallic silver by an electrolytic technique, where the silver-containing material is placed in an anode box for an electrolytic reaction, and nitric acid and silver nitrate are used as electrolytes, and the metallic silver is obtained at a cathode. For example, CN101914785B discloses a method for recovering silver and copper from silver-copper alloy wastes, where an electrolysis is performed by using a titanium plate as a cathode, loading the silver-copper alloy wastes into an anode titanium basket as an anode, and using silver nitrate solution as an electrolyte to recover electrolytic silver powder.
The disadvantages of this method are as follows. 1) This method is only suitable for materials with good conductivity. For materials with poor conductivity (such as spent catalysts containing silver and alumina support), the anode zone is filled with the spent catalyst. As the electrolysis proceeds, the silver content in the pores gradually decreases, the insulating carrier (alumina, etc.) hinders the passage of current (the resistance increases), the voltage significantly rises, and the power consumption increases. 2) Due to the existence of the insulating carrier, it is difficult for the anode to directly contact the metallic silver in the pores. Therefore, the anode actually undergoes water electrolysis (producing oxygen and nitric acid) rather than the dissolution of metallic silver, resulting in an increasing consumption of silver in the electrolyte, making the electrolysis process unsustainable. Even considering the dissolution effect of newly produced nitric acid on silver, the traditional method still encounters the same problems of producing nitrogen oxides by dissolving silver with nitrogen nitrate. 3) Due to the limitation of the silver nitrate-nitric acid system, in the absence of other intermediary oxidants, the anode should be in direct contact with metallic silver and undergo an electrolytic reaction of silver to achieve a better effect. Moreover, the spent catalyst should be placed in the anode zone and should be as close as possible to the surface of the anode, which still cannot avoid the increase in resistance and the side reaction of silver nitrate dissolving silver caused by the low silver content. 4) When the silver-containing materials are placed in the electrolytic cell, the impurities therein directly enter the electrolyte, which affects the purity of the product, and the addition and discharge of the materials interfere with the electrolytic process, resulting in a complicated operation.
Based on the above reasons, it is necessary to develop a novel process for cleanly extracting metallic silver.

Method for cleanly extracting metallic silver

INSTITUTE OF PROCESS ENGINEERING, CHINESE ACADEMY OF SCIENCES


A gravity fed display device for displaying hangable articles comprising a mounting board, including a display surface, a suspension apparatus downwardly extending from the mounting board, and a guide apparatus extending substantially parallel to the suspension apparatus. The hangable articles are suspended from the suspension apparatus and the hangable articles rest against the guide apparatus so that they hang parallel to one another. The mounting board may be a peg board and the suspension apparatus may be a peg hook. The suspension apparatus may include an upwardly extending portion and the guide apparatus may include an upwardly extending portion.

Display systems for pegboards are well known and typically include a metal peg hook inserted into a pegboard. Multiple hangable articles, such as cardboard blister packages, hang from the peg hook.
Often the peg hook extends downwardly from the peg board so that as one hangable article is removed from an end of the peg hook, the remaining hangable articles slide down the peg hook toward the end. In other words, the force of gravity causes the hangable articles to be fed along the peg hook. Thus, once a consumer removes a hangable article from the end of the peg hook, the remaining hangable articles slide along the peg hook, and another hangable article is thus displayed at the end of the peg hook. In order to prevent the hangable articles from sliding off the end of the downwardly extending peg hook, the peg hook is typically angled upward at the end, resulting in a bend in the peg hook.
As a result of gravity, the hangable articles press against each other along the peg hook. Often the hangable articles are irregularly shaped, bulky or are thinner at the top of the article. As a result, the hangable articles will fan forward and backward and bunch together as they rest against each other near the bend of the peg hook. The resulting appearance of the hangable articles is disorderly, which is undesirable, for example, in a retail store location.
It is therefore an object of the present invention to provide a novel gravity feed combined display and storage unit. It is a further object of the present invention to provide a gravity feed system with a guide so that the hangable articles hang parallel to one another from a peg hook.


The present invention is intended to provide a text-to-speech synthesis apparatus, including a storage for storing phoneme data of a plurality of speakers; a selector for selecting one of the plurality of speakers in accordance with an operation performed by a user; a searcher for searching the storage for phoneme data of the speaker selected by the selector; a text-to-speech synthesis processor for linking the phoneme data of the speaker retrieved by the searcher to convert input data into a synthetic speech; and a fee-charge controller for controlling a fee-charge operation for the user in accordance with the phoneme data selected by the selector. Consequently, the user can perform text-to-speech synthesis on the desired input data such as drama data by use of the obtained phoneme data.

The present invention relates generally to a text-to-speech synthesis system capable of generating synthetic speech in accordance with drama data for example on the basis of user-specified phoneme data.
Conventional text-to-speech synthesis apparatuses performs language analysis on entered character data and link the analyzed character data with phoneme data stored in their storage sections in accordance with predetermined rules to generate synthetic speech. These text-to-speech synthesis apparatuses may link the character data with stored male phoneme data or female phoneme data for example to sound the character data in male or female voice.
Some writers want to their novels and dramas for example to be recited by their favorite readers such as actors and actresses for example. Actually, however, the achievement of this objective is very difficult because these writers must pay costly recitation fees and make the cumbersome arrangements with readers such as their work schedules, for example. Especially, for amateur writers, it is virtually impossible to make their writings be recited by professional readers.
Normally, the above-mentioned conventional text-to-speech synthesis apparatuses can generate synthetic speech only on the basis of the phoneme data stored in their storage sections and therefore cannot generate the synthetic speech of user's specified readers.


Methods, apparatus and systems for the detection of defects in transparent substrates such as glass sheets are disclosed. The methods, apparatus and systems are capable of detecting optical path length variations in transparent substrates smaller than 100 nm.

Defects in transparent substrates such as glass sheets are typically detected utilizing human inspectors and manual methods. For example, in the detection of defects such as cord and streak in glass substrates used in liquid crystal displays (LCDs), a shadow method is used to detect the defects. According to this method, a sheet of glass (typically about 1 meter wide×2 meters long) is mounted in a freely rotating L-bracket stand and illuminated by a xenon light source. The light source is diverging to illuminate the entire sheet. The shadow of the glass is viewed on a white screen by an inspector. The defects appear as one dimensional lines of contrast on the screen. The direction of the lines is parallel to the direction the glass sheets are drawn, for example in a downdraw apparatus in which glass sheets are manufactured. Streak defects typically appear as a single isolated line, whereas cord defects consist of multiple lines spaced every few millimeters.
Cord defects typically consist of optical path length (OPL) variations as small as a few nanometers with periods of a few millimeters. These small variations, resulting from thickness or refractive index variations, modulate the light intensity on the screen by an effect commonly referred to as lensing. Repeatable and reliable visual inspection of cord and streak defects has proven to be extremely difficult, especially using manual methods. Accordingly, it would be desirable to provide apparatus, systems and methods capable of measuring one-dimensional optical path length variations of transparent substrates.

Inspection of transparent substrates for defects


An output MOS transistor and a current-detecting MOS transistor are connected commonly at their drains and gates. A gate voltage is fed to the gates of these transistors via signal lines. When the voltage of an output terminal is increased in response to excessive load current, a current-mirror circuit consisting of first and second transistors pulls in current from the signal line to reduce the gate voltage. Thus, the output current of output MOS transistor is limited within a predetermined level. Furthermore, a diode, provided in the signal line, produces a voltage drop equivalent to the base-emitter voltage of first transistor. By the function of this diode, the gate-source voltage of output MOS transistor is equalized with the gate-source voltage of current-detecting MOS transistor. As a result, the same operating point can be set for the output transistor and the current-detecting transistor.

1. Field of the Invention
The invention relates to a load actuation circuit used for actuating or driving an electrical load, and more particularly to a load actuation circuit having a function of limiting the load current supplied to the electrical load within a predetermined value or a function of protecting the load actuation circuit against excessive load current.
2. Related Art
Laid-open Japanese Patent Application No. 5-327442 discloses a conventional load actuation circuit that has a function of limiting the load current when the load current becomes an excessive value.
According to the load actuation circuit disclosed in this prior art, an output MOS transistor is provided to supply load current to an electrical load. The drain and gate terminals of this output MOS transistor are connected respectively to the drain and gate terminals of a current-detecting MOS transistor. A current-controlling NPN transistor is connected to the source of the current-detecting transistor. When the load current flowing across the output MOS transistor becomes an excessive value, the gate voltage applied to both of the output MOS transistor and the current-detecting MOS transistor is suppressed by the control of this NPN transistor. Thus, the current flowing across the output MOS transistor is limited within a predetermined value.
However, according to the above-described conventional arrangement, only one NPN transistor is used to perform a current-limit operation to suppress the excessive load current. Accordingly, there is a problem that the temperature characteristics of the NPN transistor may deteriorate the accuracy in the current-limit operation.
Provision of the NPN transistor causes a difference between the gate-source voltage of the output MOS transistor and the gate-source voltage of the current-detecting MOS transistor. Such a difference usually differentiates the operating point of the output MOS from the operating point of the current-detecting MOS transistor. This possibly results in an unstable current-detecting operation.


In a processor (110) that performs multiple instructions in a single cycle, predicts outcomes of branch conditions and speculatively executes instructions based on the branch predictions, a method and apparatus for operating a data stack utilize a remap array (674) to support a stack exchange capability. The remap array is used to correlate a stack pointer (672) to data elements (700) within the stack. A lookahead stack pointer (502) and remap array (504) are updated to preserve the processor's state of operation while speculative instructions are executed.

1. Field of the Invention The present invention relates to a processor stack and, more particularly, to a stack and stack operating method for processors that engage in speculative execution of instructions.
2. Description of the Related Art
Processors generally process a single instruction of an instruction set in several steps. Early technology processors performed these steps serially. Advances in technology have led to pipelined-architecture processors, called scalar processors, which perform different steps of many instructions concurrently. A "superscalar" processor further improves performance by supporting concurrent execution of scalar instructions. In a superscalar processor, instruction conflicts and dependency conditions arise in which an issued instruction cannot be executed because data or resources are not available. For example, an issued instruction cannot execute when its input operands are dependent upon data calculated by other instructions that have not yet completed execution.
Superscalar processor performance is improved by continuing to decode instructions regardless of the ability to execute instructions immediately. Decoupling of instruction decoding and instruction execution requires a buffer, called a lookahead buffer, for storing dispatched instruction information used by the circuits, called functional units, which execute the instructions.
The buffer also improves the processor's performance of instruction sequences that include interspersed branch instructions. Branch instructions impair processor performance because instructions following the branch commonly must wait for a condition to become known before execution can proceed. A superscalar processor improves branching performance by "speculatively" executing instructions, which involves predicting the outcome of a branch condition and proceeding with subsequent instructions in accordance with the prediction. The buffer is implemented to maintain the processor's speculative state. When a misprediction occurs, the results of instructions following the mispredicted branch are discarded. A superscalar processor's performance is greatly enhanced by a rapid recovery from a branch misprediction and restart of an appropriate instruction sequence. Recovery methods cancel effects of improperly performed instructions. Restart procedures reestablish a correct instruction sequence.
One recovery and restart method, taught by Mike Johnson in Superscalar Processor Design, Englewood Cliffs, N.J., Prentice Hall, 1991, p. 92-97, employs a reorder buffer and a register file. The register file holds register values generated by retired operations--operations that are no longer speculative. The reorder buffer holds speculative results of operations--results of operations that are executed in a sequence following a predicted but unverified branch. The reorder buffer operates as a first-in-first-out queue. When an instruction is decoded, an entry is allocated at the tail of the reorder buffer. The entry holds information concerning the instruction and the result of the instruction when it becomes available. When an entry that has received its result value reaches the head of the reorder buffer, the operation is retired by writing its result to the register file. The reorder buffer is used by a processor during recovery after a branch misprediction to discard register values made by instructions that follow a mispredicted branch. Although a reorder buffer effectively restores registers following a mispredicted branch, other processor registers may need to be restored as well. For example, in a processor that employs a stack for managing data, the stack requires restoration. Stack restoration requires recovery of all stack elements, including array elements and pointers.
One example of a stack is the floating point unit (FPU) register stack of the Pentium.TM. microprocessor, available from Intel Corporation of Santa Clara, Calif. The FPU register stack is an array of eight multiple-bit numeric registers that stores extended real data. FPU instructions address the data registers relative to the top of the stack (TOS). A floating point exchange (FXCH) instruction in the Pentium.TM. microprocessor exchanges contents of the top of the stack with the contents of a specified stack element, for example a default element at the penultimate location of the stack relative to the TOS. The FXCH instruction is useful because Pentium.TM. floating point instructions generally require one source operand to be located at the top of the stack and, most frequently, the result of a FPU instruction is left at TOS. Most FPU instructions require access to the TOS, so it is desirable to manipulate data positions within the stack using the FXCH instruction.
The top of the stack is identified by the TOS pointer. Stack entries are pushed and popped by the execution of some floating point instructions and data load and store instructions. Since these instructions depend on programming of the processor, floating point overflows and underflows can occur and must be trapped, generating an exception condition. An exception condition, like a mispredicted branch, requires restoration of the speculative state of the processor.
One consequence of the FXCH instruction is that it introduces variability into the order of stack elements which complicates restoration of the stack following a mispredicted branch or exception.
In a superscalar processor, mispredicted branches and exceptions occur, making effective recovery and restart procedures desirable. What is sought are a stack and method of operating a stack for simply and rapidly restoring the state of a stack.

Floating point stack and exchange instruction


In detecting patterns in data arranged in a spatial field of one, two or higher dimension, a pattern contrast signal is evaluated which measures the similarity to the pattern of the data around a location in the spatial field. The pattern is subsequently detected if the pattern contrast signal is sufficiently strong. There is, however, a risk of erroneous detection when a coincidental noise configuration causes an increased pattern contrast signal. The invention provides for a method and apparatus to discriminate against such erroneous detections. For this purpose, the method observes the extent to which a would-be pattern dominates the effect on the pattern contrast signal of the distribution of data values in the surroundings of the location, this distribution being taken to be typical of noise. In one embodiment, this is done by confirming that the pattern is sufficiently strong to suppress any other would-be pattern detections in the surroundings. In another embodiment, this is done by confirming that the pattern contrast signal responds as expected in the noise free case when the spatial field is rescaled around the location before evaluating the pattern contrast signal.

Field of the Invention
The present invention relates to a method and device for distinguishing patterns and, more particularly, to a pattern detection system such as a signal processing or signal analysis system for distinguishing true pattern responses from noise pattern responses. Typical patterns are edges in images. The present invention can be applied, for example, to the field of medical image analysis or to the field of robot vision.

Method and device for detecting patterns adapted automatically for the level of noise


A mixing device includes a signal data generation unit that generates signal data on a time-frequency plane composed of a time-axis and a frequency-axis from each of two or more input signals derived from a time domain, a signal processing unit that receives the signal data for the two or more input signals, and performs a mixing process that includes an adding operation of the signal data for each corresponding point on the time-frequency plane of the signal data for each of the input signals, and an output signal generation unit that receives the operation result of the signal processing unit and outputs an output signal formed by converting the inputted signal into a signal of a predetermined format.

Conventionally-used mixers including from a mixing console for use in a studio and to a mixer for amateurs are provided with basic operations for carrying out a mixing process by computing a weighted sum of respective input voice signals. In the case when the weighted sum is insufficient, an effects unit is coupled to an input and/or an output of the mixer so that by adding a linear or non-linear operation process thereto, target sound quality and sound field feeling can be realized. Upon mixing a musical instrument sound A with a voice B, in order to allow the voice B to be clearly heard even after the mixing process, the following methods are proposed.
A first method is to use a linear filter. More specifically, by using an equalizer that is one type of effects unit, a filtering process is carried out on an essential frequency band of the voice B so as to attenuate the same frequency band as that of the musical instrument sound A so that the hearing of the voice B is prevented from being interrupted by the musical instrument sound A. Non-Patent Document 1 has disclosed a method by which, with respect to a mixing process of a base guitar and a bass drum, a band in the vicinity of 200 Hz of the frequency band of a sound of the bass drum is attenuated so as to prevent the sound of the base guitar from being interrupted by the sound of the bass drum.
A second method is to use a processing system referred to as "ducker" described in Non-Patent Document 2. By using the ducker, for a time section in which the output level of a voice is kept at a fixed value or more, the musical instrument sound is attenuated by a fixed attenuation amount, and by overlapping the voice with the musical instrument sound after having been attenuated, these sound sources can be mixed with each other without the voice being interrupted by the musical instrument sound.
As another example similar to the second method, Patent Document 1 has described a technique relating to a sound calming process of audio sound source in which in the case when during reproduction of a music by a car stereo system, an attempt is made to make a voice from a navigation device more conspicuous only to the driver, the music that is being reproduced is subjected to a sound calming process and the navigation voice is mixed with the sound source subjected to the sound calming process.

Mixing device, mixing signal processing device, mixing program and mixing method

The University of Electro-Communications


A field emission cathode includes a first electron-emitting structure having a first cathode electrode (3), a first gate electrode (5), a first insulating layer (4) separating the first cathode electrode (3) from the first gate electrode (5), and at least one first emitter tip (9) disposed in a hole formed in the first gate electrode (5) and the first insulating layer (4) to expose a portion of the first cathode electrode (3); and a second electron-emitting structure surrounding and insulated from the first electron-emitting structure wherein the second electron-emitting structure has a second cathode electrode (6), a second gate electrode (8), a second insulating layer (7) separating the second cathode electrode (6) from the second gate electrode (8), and at least one second emitter tip (10) disposed in a hole formed in the second gate electrode (8) and the second insulating layer (7) to expose a portion of the second cathode electrode (6).

1. Field of the Invention
The present invention relates generally to field emission cathodes and methods of cleaning therefor.
2. Description of the Related Art
Electron sources or cathodes are essential to the functioning of all electron cathodes. Traditionally, cathodes for vacuum cathodes such as vacuum tubes and cathode ray tubes used thermionic emission to produce the required electrons. This required raising cathode materials to very high temperature conduction of current either by direct or through the use of auxiliary heaters. The process is very inefficient, requiring relatively large currents and dissipating most of the energy as wasted heat.
In recent years there has been a growing interest in replacing the inefficient thermionic cathodes with high field emission cathodes. These cathodes are very efficient because they eliminate the need to heat the cathode material. They have been used for a number of years as sources for scanning electron microscopes, and are now being investigated as sources for vacuum microelectronic cathodes, flat panel displays, and high performance high frequency vacuum tubes.
Field emission cathodes include very sharp points of field emission materials. These sharp points when biased with negative potential concentrate the electric field at the point. This high electric field allows the electrons to "tunnel" through the tip into surrounding space which is normally maintained under high vacuum conditions. The magnitude of the potential required to produce sufficiently strong electric fields is proportional to the distance between the tip and the principal extraction electrode. This principal extraction electrode will be referred to as the extraction electrode. While this extraction electrode can be a physically separate structure, minimum extraction potentials can most conveniently be obtained by physically integrating the extraction electrode directly with the field emission tips. This produces very small extraction electrode-cathode distances, which are physically locked in proper alignment. Field emission cathode structures both with and without integrated extraction electrodes are useful electron sources in a variety of current and potential applications such as displays, Vacuum Microelectronic Cathodes, and various electron microscopes.
The field emission display elements that utilize these cathodes use the basic field emission structure and add additional structures, such as, an extension of the vacuum space, a phosphor surface opposite the cathode tip, and additional electrodes to collect and/or control the electron current. Groups of individual Vacuum Microelectronics Cathodes and/or display elements are electrically interconnected during fabrication to form integrated circuits and/or displays.
While these field emission cathode structures can be made in almost any size and may have application as discrete sources, their best performance and major application is expected to come from extreme miniaturization, and dense arrays.
Non-thermionic field emitters, field emission cathodes, and field emission displays are all known in the art. The fabrication of the field emission cathode structure is a critical element common to the cathode mentioned. The material (insulators and conductors/field emitters) are all deposited and processed by relatively common deposition and lithographic processing techniques with the single exception of special sharp edge (blade) or point (tip) structure which is common to all field emission cathodes.
The art of fabricating the sharp field emission tip or blade can be classified into several categories.
In one of the earliest categories, the cathode tip structure is formed by the direct deposition of the material. An example of this type is described in a paper by C. A. Spindt, "A thin-Film Field-Emission Cathode", Journal of Applied Physics Vol. 39, No. 7, page 3504 (1968). In this paper, sharp molybdenum cone-shaped emitters are formed inside holes in a molybdenum anode layer and on a molybdenum cathode layer. The two layers are separated by an insulating layer that has been etched away in the areas of the holes in the anode layer down to the cathode layer. The cones are formed by simultaneous normal and steep angle depositions of the molybdenum and alumina, respectively, onto the rotating substrate containing the anode and cathode layers.
In this developing field, the art has produced closely packed arrays of such cones. One of the fabrications of arrays of cones is exemplified in a paper by C. A. Spindt, I. Brondie, L. Humphrey, and E. R. Westberg, `Physical properties of thin-film field emission cathodes with molybdenum cones", Journal of Applied Physics, Vol. 47, No. 12, pages 5248 to 5263 (1976).
In this paper, field emission cathodes fabricated using thin-film techniques and microlithography are described, together with effects obtained by varying the fabrication parameters. The emission originates from the tip of molybdenum cones that are about 1.5 .mu.m tall with a tip radius around 500 angstroms. Such cathodes have been produced in closely packed arrays containing 100 and 5000 cones as well as singly. Minimum currents in the range 50-150 .mu.A per cone can be drawn with applied voltages in the range 100-300 V when operated in conventional vacuum at pressures 10.sup.-9 Torr or less. In the arrays, current densities (averaged over the array) of above 10 A/cm.sup.2 have been demonstrated.
These field emission cathodes and extraction electrodes can be used in practical applications, such as flat-panel displays. In the display applications, beam focusing is required as is discussed in a paper by W. Dawson Kesling, and Charles E. Hunt entitled "Beam Focusing for Field-Emission Flat-Panel Displays", IEEE Transactions on Electron Cathodes, Vol. 42, No. 2, pages 340 to 347, February 1995. In the paper, two focused designs have been shown to yield exceedingly small beam widths. One design uses an aperture electrode parallel to the gate electrode on the cathode substrate for beam focusing. The other is a concentric electrode design, in which the focus electrode lies in the same plane as the gate electrode and surrounds each emission tip.
In the practical applications, it is necessary to avoid disruption of the cathode in life. This disruption is caused by a local gas discharge forming between the tips and the gate electrode. Gas out of the active components of the cathode, including the cathode itself, is the main source of gas for this discharge. It is known that bombarding all the active parts of the cathode (including the cathode) with electrons can eliminate this effect. The several bombarding techniques have been described in JP-A 4-22038, JP-A 5-198255, and JP-A 114353.
JP-A 4-220388, which apparently corresponds to U.S. Pat. No. 5,189,341, describes electron-bombarding technique. A plurality of pairs of cathodes separated from each other is used. A portion of electrons from emitter tips on one cathode of each pair is drawn toward emitter tips on the other cathode for electron bombardment when the emitter tips on the other cathode do not emit electrons. A portion of electrons from the emitter tips on the other cathode is used for bombardment of the emitter tips on the one cathode.
JP-A 5-198255, which appears to correspond to EP-A 0 541 394, describes an electron-bombarding technique in which an anode electrode is used to direct substantially all of electrons from emitter tips on one cathode to emitter tips on the adjacent cathode.
JP-A 5-114353 shows, a plurality of emitter tips surrounding an emitter tip on a cathode. The surrounding emitter tips emit electrons for bombardment of the emitter tip surrounded thereby. The surrounding emitter tips are formed on an extraction electrode of the surrounded emitter tip. Thus, the extraction electrode is negatively biased for urging the surrounding emitter tips to emit electrons and the cathode of the surrounded emitter is positively biased to draw the electrons. According to this arrangement, positive voltage applied to the cathode cannot be increased to a sufficiently high level because the extraction electrode is negatively biased. This is because the difference in potential between the surrounded emitter tip and the extraction electrode must be low enough not to induce electrical discharge across a gap between them.
JP-A 60-1741 describes an electron gun in which a filament is opposed to an anode to heat the surface of the anode during a gas discharge process thereby facilitating gas discharge from the anode. In operation of the cathode, the filament is positively biased thus preventing ions separated from the surface of the anode from leaving therefrom.
An object of the present invention is to provide a field emission cathode that makes it possible and easy to clean not only emitter tips but also electrodes by electron-bombarding during discharge process before sealing a space around the emitter tips and electrode.
A specific object of the present invention is to provide a field emission cathode that allows beam focusing to yield small electron beam widths after electron-bombarding of electrodes as well as emitter tips during discharge process.
Another object of the present invention is to provide a method of cleaning a field emission cathode during gas discharge process before sealing a space around emitter tips and electrodes.

Field emission cathode and cleaning method therefor


Tertiary amines corresponding to the formula Z.sub.2 Z'N in which Z is a 3,5-dihydrocarbyl-4-hydroxyphenalkyl group having the structure: ##STR1## wherein R is hydrogen or an alkyl group of 1-3 carbons; R' and R" are hydrocarbyl groups independently selected from alkyls and cycloalkyls of up to six carbons; n represents zero or one; and Z' is Z or an alkyl, alkenyl, or aralkyl group of up to 18 carbons are novel compounds having antioxidant activity in organic materials which are normally susceptible to oxidative deterioration. They are especially valuable as antioxidants for lubricants.

Various phenolic compounds have been found to have utility as antioxidants in organic materials which are normally susceptible to oxidative deterioration. Many of these antioxidants--including the secondary and tertiary 3,5-dialkyl-4-hydroxybenzylamines of U.S. Pat. Nos. 3,043,774 (Coffield) and 3,115,466 (Orloff et al.) and the N,N-bis(3,5-dialkyl-4-hydroxyphenalkyl)amides of U.S. Pat. 5,120,792 (Gatto)--can be used to stabilize a variety of materials against oxidative degradation but have limited use in lubricants and other oils because of being solids with low solubility in oils. It would be desirable to find antioxidants which would have sufficient solubility in such materials, as well as in other normally oxidizable organic materials, and have melting points and degrees of volatility and thermal stability such as to make them more useful in stabilizing the materials against oxidative degradation.


In a center, a Fourier transformation with a weighting function and a center matrix are applied to the identifier of each entity (steps 2-1, 2-2), which is then randomized by one-time pass random number data generated by a manual operation at each entity, thereby generating a secret private key peculiar to each entity (steps 2-3.about.2-5). The center also generates an identifier transformation algorithm based on the one-time pass random number data and the Fourier transformation with a weighting function (step 2-6). Thereafter, the center distributes the identifier transformation algorithm and the secret private key to each entity. Each entity applies the identifier transformation algorithm and the secret private key to the identifier of another entity with which to communicate, for thereby generating a common cryptokey for cryptographic communications between the entities.

1. Field of the Invention
The present invention relates to a method of sharing a cryptokey for cryptographic communications between entities on a computer network.
2. Description of the Prior Art
Recent years have seen a pressing need for ciphertext communication technology to keep communication data secret from third parties for communications on a network such as the Internet.
One well known type of such ciphertext communication technology is a form of public key cryptography known as RSA. Another form of ciphertext communication technology which is generally known in the art is a process of sharing a cryptokey used for communications between entities on a network. According to such a process of sharing a cryptokey, a transmitting entity encrypts communication data of a plaintext using a cryptokey and then transmits the cryptographic communication data to a receiving entity. Then, the receiving entity decrypts the received cryptographic communication data back into the original communication data, using the same cryptokey as the cryptokey used by the transmitting entity. The term "entity" used above signifies any existing body for carrying out communications, e.g., a device such as a terminal connected to the network, a user of the device, a program for operating the device, a combination thereof, or the like.
Conventional attempts to realize the process of sharing a cryptokey are disclosed in "NON-PUBLIC KEY DISTRIBUTION/Advances in Cryptography: Proceedings of CRYPTO '82/Plenum Press, 1983, pp. 231-236" by Rolf Blom, "An Optimal Class of Symmetric Key Generation Systems/Advances in Cryptology: EUROCRYPT '84/Springer LNCS 209, 1985, pp. 335-338" by Rolf Blom, Japanese patent publication No. 5-48980, and U.S. Pat. No. 5,016,276, for example.
According to the above disclosed proposals, a center or central facility established on the network generates a secret private key for each of the entities for generating a common cryptokey and distributes the generated secret private key to each of the entities. When the entities communicate with each other, each of the entities applies its own secret private key to the other entity's identifier (name, address, or the like), generating a common cryptokey shared by the entities.
In the above process, the secret private key for each of entities is generated by transforming the identifier of each entity according to a center algorithm which is held by the center only and common to the entities.
More specifically, if the center algorithm is expressed as a function P(x, y) of variables x, y representing two arbitrary identifiers, respectively, then the center algorithm is established so that it has a symmetry represented by P(x, y)=P(y, x). A function P(x, i) (hereinafter expressed as "Pi(x)") which is generated when the actual identifier i of each of the entities is substituted in the value of the variable y, for example, of the variables x, y of the function P(x, y) is distributed as a secret private key to each entity. When the entity having the identifier i subsequently communicates with the entity having the identifier j, the entity having the identifier i applies the identifier j of the other entity to its own secret private key Pi(x), i.e., sets the variable x to "j", thus generating a cryptokey Pi(j). Similarly, the entity having the identifier j applies the identifier i of the other entity to its own secret private key Pj(x), thus generating a cryptokey Pj(i). Since the center algorithm has the above symmetry, the cryptokey Pi(j) is equal to the cryptokey (Pi(j)=Pj(i)). Therefore, the entities having the respective identifiers i, j have obtained a common cryptokey.
With the above process of sharing a cryptokey, each entity can obtain a cryptokey common to itself without any other arbitrary entity involving the center simply by applying the identifier of the arbitrary entity to its own secret private key. Consequently, the above process of sharing a cryptokey is effective to simplify a cryptosystem on a computer network.
According to the above process of sharing a cryptokey, it is important that the center algorithm should not easily be analyzed in order to keep ciphertexts secret.
While the above process of sharing a cryptokey offers the advantages described above, the secret private keys of respective entities, a cryptokey generated from the secret private keys, and communication data encrypted by the cryptokey thus generated all contain information regarding the center algorithm. Because the center algorithm is common to the entities, it is generally open to attack by a plurality of collaborating entities as described in "Performance of Linear Schemes for the Keypredistribution System/IEICE Technical Report on Information Security, May 20, 1988, pp. 29-32" by Matsumoto.
If entity names are used as identifiers, then since many similar names tend to occur, the identifiers are not well dispersed, i.e., the distribution of the identifiers is liable to be localized. Many of the secret private keys of the entities which are produced by applying the center algorithm to those identifiers tend to be analogous to each other. As a result, cryptographic communication data are subject to so-called differential attack.
Consequently, there has been a demand for increased security against various forms of attack against the above process of sharing a cryptokey.


A method for producing a Ga-containing group III nitride semiconductor having reduced threading dislocation is disclosed. A buffer layer in a polycrystal, amorphous or polycrystal/amorphous mixed state, comprising AlGaN is formed on a substrate. The substrate having the buffer layer formed thereon is heat-treated at a temperature higher than a temperature at which a single crystal of a Ga-containing group III nitride semiconductor grows on the buffer layer and at a temperature that the Ga-containing group III nitride semiconductor does not grow, to reduce crystal nucleus density of the buffer layer as compared with the density before the heat treatment. After the heat treatment, the temperature of the substrate is decreased to a temperature that the Ga-containing group III nitride semiconductor grows, the temperature is maintained, and the Ga-containing group III nitride semiconductor is grown on the buffer layer.

1. Field of the Invention
The present invention relates to a method for producing a Ga-containing group III nitride semiconductor having reduced threading dislocation.
2. Description of the Related Art
A method of forming a low temperature buffer layer on a sapphire substrate by a metal organic chemical vapor deposition method (hereinafter referred to as an "MOCVD method") and growing GaN on the buffer layer has conventionally been known.
For example, in JP-A-2005-19872, a sapphire substrate is heat-treated at 1,135° C. to clean the surface thereof, a substrate temperature is decreased to 515° C., a buffer layer comprising GaN having a thickness of 20 nm is formed, the substrate temperature is increased to 1,075° C., and fine crystals of GaN are formed on the sapphire substrate. Thereafter, the temperature is maintained, hydrogen gas ratio is made larger than nitrogen gas ratio, and GaN is facet-grown using fine crystals of GaN as nuclei. Thereafter, the substrate temperature is decreased to 1,005° C., nitrogen gas ratio is made larger than hydrogen gas ratio, making it easy to grow in a horizontal direction, and GaN is grown so as to fill spaces among facets. Thus, GaN having reduced threading dislocation density is obtained.
In Example 3 of JP-A-2005-183524, a sapphire substrate is thermally cleaned at 1,200° C., a substrate temperature is set to 1,200° C., AlN is epitaxially grown, and a monocrystal underlying layer 102 having a thickness of 0.7 μm is formed. The substrate temperature is decreased to 1,150° C., an AlGaN layer 103 is epitaxially grown in a thickness of 100 nm or less, and an annealing treatment is conducted by maintaining the substrate temperature at 1,350° C. for 10 minutes. The substrate temperature is then decreased to 1,150° C., and an AlGaN layer 104 is grown. Thus, threading dislocation density of the AlGaN layer is reduced.
However, the method of JP-A-2005-19872 is a method that after forming a low temperature buffer layer comprising ultra thin GaN having a thickness of 20 nm at low temperature, the temperature is increased to a temperature capable of growing GaN to form fine crystals of GaN, and subsequently, GaN is facet-grown. Therefore, after formation of the low temperature buffer layer, the temperature of the substrate is merely increased up to a temperature capable of growing GaN, and therefore, crystal nuclei of fine crystals are small. As a result, density of occurrence origin of threading dislocation is still large.
The method of JP-A-2005-183524 is that an underlying layer 12 on a substrate 11 is epitaxially grown in a thickness of 0.7 μm, and is therefore fine crystal. Furthermore, the AlGaN layer 103 is epitaxially grown on the underlying layer 102 of fine crystal, and is therefore fine crystal. Annealing at a stage that the AlGaN layer 103 has been formed facilitates movement of dislocation in the AlGaN layer 103, thereby reducing threading dislocation (paragraph 0032).
Therefore, P-A-2005-183524 does not increase crystal nuclei in a buffer layer in a polycrystal, amorphous or polycrystal/amorphous mixed state, and does not inhibit formation of threading dislocation density in an objective semiconductor layer to be grown.
JP-A-2005-19872 relates to a heat treatment for obtaining crystal nuclei for facet growth, and does not decrease density of occurrence origin of threading dislocation.

Method for producing Ga-containing group III nitride semiconductor


An ion guide for mass spectrometry comprising an electrode arrangement of at least two electrodes, at least one of which is an RF electrode, arranged adjacent to each other but spaced apart on a planar surface of a dielectric material and arranged at a distance from an ion flow path, wherein a portion of the dielectric surface is exposed between an adjacent pair of the spaced apart electrodes and wherein at least one electrode of said adjacent pair of electrodes is arranged to overhang the exposed portion of surface between them such that there is no direct line of sight from the ion flow path to the exposed portion of dielectric surface. The device enables RF guiding of ions accompanied by much reduced charging-up of dielectric surfaces and reduced amount of collisions of neutral species with electrodes.

RF ion guides, such as RF multipoles, are widely used in mass spectrometry in ion optical devices. Examples of devices comprising RF ion guides include mass filters, collision cells, ion traps and transport multipoles. However, the design of such devices presents numerous challenges.
In recent years, RF ion guides with additional axial fields have been developed for better control of ion motion, for example as disclosed in U.S. Pat. No. 5,847,386, U.S. Pat. No. 6,111,250, EP1271611, U.S. Pat. No. 6,674,071, U.S. Pat. No. 6,107,628, U.S. Pat. No. 7,164,125, U.S. Pat. No. 7,064,322 and U.S. Pat. No. 7,564,025. These ion guides typically consist of massive metal or resistive RF rods, usually of circular section, and different means to provide an additional DC distribution along the axis of the guide. Such constructions are typically formed using conventional machining methods and invariably require cumbersome assembly and numerous parts.
In order to simplify the manufacturing of RF ion guides, planar designs have been developed like those described in U.S. Pat. No. 5,572,035, U.S. Pat. No. 6,040,575, U.S. Pat. No. 7,365,317, U.S. Pat. No. 7,786,435, WO2010/014077, U.S. Pat. No. 6,872,941, US2011/240850, WO2006/059123 and WO2004/021385. The latter prior art design is suitable for manufacturing by standard mass-production techniques of electronics, e.g. in the form of printed circuit boards (PCBs), or by lithography for miniaturized designs. Such concepts have been adopted for the production of miniature ion traps for quantum computing (see e.g. Chiaverini et al, Quantum Inform. And Computation, v. 5, No. 6 (2005) 419-439, as well as Kielpinski et al, Nature Vol. 417, 2002, p. 709). However, this approach has the disadvantage of not providing an effective way to construct an ion guide with a deep enough potential well for use in mass spectrometry. Other disadvantages of the foregoing designs include not providing a robust construction that could also be used to confine gas for collisional cooling of ions for example, and charging up of dielectric gaps between electrodes that can affect ion motion. Whilst there are designs without dielectric (e.g. using resistive rods to generate a gradient field), such designs are difficult to manufacture. For conventional multipoles positioned near to the ion source, a large amount of neutral species also typically collide with the multipole rods, which again can affect performance over time.
The invention has been made against this background in order to alleviate one or more of the aforementioned problems.