A steel sheet shape control method includes, (A) setting a target correction shape of the steel sheet at a position of an electromagnet to a curved shape, (B) measuring a steel sheet shape when electromagnetic correction is performed, (C) calculating the steel sheet shape in a nozzle position based on the steel sheet shape, (D) repeating (B) and (C) by resetting the target correction shape to a curved shape having a smaller amount of warp, (E) when the amount of warp of the steel sheet shape at the position of the nozzle is less than the upper limit value, (F) calculating vibration of the steel sheet at the position of the nozzle, and (G) adjusting a control gain of the electromagnet until amplitude of vibration is less than a second upper limit value when the amplitude of the vibration is equal to or more than the second upper limit value.

When a hot-dip coated steel sheet is manufactured, first, a steel sheet is conveyed in a hot-dip coating bath, and coating is applied to front and rear surfaces of the sheet. Subsequently, gas such as air is sprayed from a wiping nozzle toward the front and the rear surfaces of the sheet while the coated steel sheet is drawn outside the hot-dip coating bath and is conveyed, the coating applied to the steel sheet is wiped, and thus, the coating thickness is adjusted and the hot-dip coated steel sheet is manufactured.
In order to manufacture the hot-dip coated steel sheet having uniform coating thickness, it is necessary to make intervals between the wiping nozzle and the front and the rear surfaces of the steel sheet be as constant as possible. Accordingly, in general, a support roll for pressing the steel sheet in a through-thickness direction and flattening the steel sheet shape is installed near an outlet side in the hot-dip coating bath. However, the steel sheet shape cannot be sufficiently corrected by only the support roll, and a warp (a so-called C warp, W warp, or the like) occurs in a transverse direction in the steel sheet which is drawn out to the outside of the hot-dip coating bath.
In the related art, an electromagnetic correction technology, which uses a plurality of electromagnets to correct the warp of the steel sheet, is used. For example, Patent Document 1 discloses that in order to uniformize coating thickness at both ends of a transverse direction of a steel sheet, electromagnetic correction is performed with reference to information of a position in the through-thickness direction of the both ends of the steel sheet which is measured by a separate sensor, and the warp of the both ends of the steel sheet is corrected in an appropriate direction.
Moreover, in Patent Document 2, a technology is disclosed which adjusts dispositions in the transverse direction of a plurality of electromagnets to correspond to a change of a sheet width or meandering of a steel sheet when C warp of the steel sheet is corrected by electromagnets. Moreover, in Patent Document 3, similarly, in order to correspond to the change of the steel width or meandering of the steel sheet, a technology, which moves the electromagnets in the transverse direction, is disclosed.
In addition, in Patent Document 4, a steel sheet shape correction apparatus is disclosed which includes a control unit which automatically adjusts a pass line by moving a pair of support rolls corresponding to the output values of electromagnets on the front side and the rear side of a steel sheet.
Moreover, in Patent Document 5, an apparatus is disclosed in which a plurality of sensors and electromagnets are installed to be opposite to a strip, a position of the strip is detected by a sensor installed in the electromagnet and a sensor installed to be separated from the electromagnet, for example, installed at a position of a wiping nozzle or the like, two signals of the sensors are fed back to currents of the electromagnet, and shape correction of the strip and vibration control of the strip are performed at the position of the wiping nozzle separated from the electromagnet, or the like.
In addition, in Patent Document 6, a continuous hot-dip metal coating method is disclosed in which when a hot-dip metal coating is performed on a metal band by a continuous hot-dip metal coating line which includes a gas wiping nozzle adjusting a coating thickness, a non-contact control apparatus controlling a shape position of a metal band of the gas wiping nozzle portion in a non-contact manner, and a correction roll in a bath correcting the shape of the metal band of the gas wiping nozzle portion in a hot-dip metal coating bath, a determination is performed of whether or not the shape position of the metal band of the gas wiping nozzle portion can be controlled by only the non-contact control apparatus based on at least a thickness of the metal band to be hot-dip metal coated. When the shape position of the metal band of the gas wiping nozzle portion can be controlled by only the non-contact control apparatus, the shape position of the metal band is controlled by only the non-contact control apparatus to make the correction roll in the bath not contact the metal band. When the control of the shape position of the metal band is made difficult by only the non-contact control apparatus, the shape position of the metal band is controlled by only the correction roll in the bath or by using both the correction roll in the bath and the non-contact control apparatus.

Steel sheet shape control method and steel sheet shape control apparatus

NIPPON STEEL & SUMITOMO METAL CORPORATION


An example method for congestion control using congestion prefix information in a Named Data Networking (NDN) environment is provided and includes sensing, at a first node, congestion preventing an interest packet from being forwarded over a link to a second node, generating a prefix marker associated with a class of traffic to which the interest packet belongs, generating a negative acknowledgement (NACK) packet that includes the prefix marker, the NACK packet being indicative of congestion for any interest packet in the class of traffic indicated by the prefix marker over any path that includes the link, and transmitting the NACK packet over the NDN environment towards a sender of the interest packet.

The Internet was initially designed for point-to-point communication. However, communication modes have dramatically changed since then, particularly with increased use of content distribution. For example, applications are typically written in terms of what information is being used rather than where the information is located; consequently, application specific middleware is used to map between the application's model and the Internet's model. Accordingly, there is a push towards replacing Internet's Internet Protocol (IP) architecture with content oriented networking architecture, such as Named Data Networking (NDN) and Content Centric Networking (CCN).

Congestion control using congestion prefix information in a named data networking environment


A headphone apparatus includes sound reproduction units which respectively reproduce sound signals and are arranged so as to be separated from ear auricles of a headphone user, wherein each of the sound reproduction unit is configured by a speaker array including a plurality of speakers.

The present disclosure relates to a headphone apparatus and a sound reproduction method for the headphone apparatus, and particularly to a headphone apparatus and the like which reproduces two-channel sound signals.
In the related art, there is a sound reproduction method according to which a headphone user (listener) wears a headphone on his/her head so as to cover both ears and listens to a sound signal (acoustic signal) from both ears. According to the sound reproduction method, a so-called lateralization phenomenon in which a reproduced sound image stays within the head of the listener even if a signal from the signal source is a stereo signal occurs.
On the other hand, there is a binaural collected sound reproduction method as a sound reproduction method by a headphone. The binaural collected sound reproduction scheme is a scheme as follows. That is, microphones called dummy-head microphones are provided for holes of both left and right ears of a dummy head on the assumption of the head of the headphone user. A sound signal from a signal source is collected by the dummy-head microphones.
If the headphone user actually wears the headphone and reproduces the thus collected sound signal, the headphone user can feel as if the headphone user were listening to the sound directly from the signal source. According to such a binaural collected sound reproduction method, it is possible to enhance a sense of direction, a sense of orientation, a sense of presence, and the like. However, it is necessary to prepare a signal source as a special source, which is different from a source for speaker reproduction, which collects sound source signals with a dummy-head microphone, in order to perform such a binaural collected sound reproduction method.
Thus, it can be considered that a reproduction effect that typical two-channel sound signals (stereo signals), for example, are used so as to be oriented outside a head (speaker positions) in the same manner as in speaker reproduction is obtained by applying the aforementioned binaural collected sound reproduction method by the headphone. In order to obtain sound image orientation outside a head with the use of a headphone, radiation impedance from entrances of external auditory canals of a headphone user to the outside becomes different from that in a case of a headphone non-wearing state.
That is, sound waves from the headphone repeats complicated reflection between ear auricles and headphone sound generating units and are transmitted from the entrances of external auditory canals to drum membranes. For this reason, even if it is attempted to transmit an optimal property to the entrances of external auditory canals or surfaces of the drum membranes, the reflection disturbs the property. Therefore, there is a disadvantage in that it is difficult to stably obtain a satisfactory sound image orientation.
For example, according to a headphone reproduction method described in Japanese Patent No. 3637596, a sound image orientation is enhanced by allowing radiation impedance from entrances of auditory canals to the outside to be close to that in the non-wearing state. That is, Japanese Patent No. 3637596 discloses that headphone sound generating units are positioned so as to be separate from ear auricles of a headphone user.

Headphone apparatus and sound reproduction method for the same


A dynamic lockout technique for mobile computing devices is provided. A mobile computing device having a user interface in an active mode identifies foreign computing devices that are connected to a shared network. The mobile computing device determines determining that each foreign computing device is a recognized device, and in response, determines whether a paired device is in proximity to the mobile computing device based on a signal transmitted by the paired device. The mobile computing device maintains the active mode if the paired device is in proximity. The mobile computing device identifies a new foreign computing device that is connected to the shared network. The mobile computing device activates a lockout mode for the user interface while the paired device is in proximity to the mobile computing device if the new foreign computing device is an unrecognized device in proximity to the mobile computing device.

In computing technology it is often necessary to regulate access to applications and data stored on a particular computing device or accessible via the computing device. Lock screens are one method of regulating access. In general, a lock screen is a user interface element that regulates access to computing resources by requiring a user to authenticate or reauthenticate themselves when the lock screen is enabled. Lock screens can be implemented on an operating system (OS) level or an application level (e.g., session timeouts). In some instances, a lock screen is enabled after a threshold period of inactivity on a user interface. In other instances, a lock screen is enabled after a user performs a specified action for locking a respective computing device or resource. When a lock screen is enabled, any attempt to access the protected resources will cause the computing device to display the lock screen. For example, a graphical user interface may display a lock screen including elements for entering user identification (e.g., a user ID) and/or a password prior to permitting a user access to the protected resources. In addition to one or more means of authenticating a user, a lock screen may present a limited amount of additional information, (e.g., a date and time, weather conditions, or other non-restricted information) and/or may allow varying degrees of access to a limited number of applications (e.g., a clock application, a weather application, or other non-restricted applications).

Managing dynamic lockouts on mobile computing devices

International Business Machines Corporation


System, method, and computer program product to autocorrect text for the purpose of matching words from an approved corpus, by: responsive to receiving a text input comprising a first word, validating the first word against a content corpus, wherein the content corpus comprises a plurality of words approved for display in an online chat, validating the first word against a set of rules, and upon determining that the first word of the text input is not validated against at least one of the content corpus and the set of rules, modifying the text input by replacing the first word with a first approved word from the content corpus.

1. Field of the Invention
Embodiments disclosed herein relate to computer software which autocorrects text entered in a chat application to match the text to approved words in an approved corpus.
2. Description of the Related Art
Currently, text-based communication applications correct words based on typos and grammatical errors. These solutions are ineffective when the applications are used by children or other sensitive groups, who may require some amount of censorship to ensure that inappropriate material is not transmitted through the application.

Autocorrecting text for the purpose of matching words from an approved corpus


Method and system for a network device having a plurality of ports for sending and receiving information is provided. The device includes a global quality of service (QOS) module for receiving QOS information from a plurality of QOS modules regarding bandwidth used by the plurality of ports for sending information. For selecting a request from among a plurality of pending requests from the plurality of ports to transmit information, the global QOS module adds bandwidth consumed by the plurality of ports when the ports belong to a non-local link aggregation group (LAG). The global QOS module uses local QOS information from a same QOS bin assigned to the plurality of ports, when the plurality of ports belong to a local LAG.

Mixing protocols on a same network device may need different quality of service (QOS) methods. For example, for Fibre Channel protocol, QOS may be used to balance traffic across multiple Inter-Switch Links (ISLs). For Ethernet QOS may be used to implement QCN and ETS. Implementing QOS becomes complex when a port is a part of a link aggregation group (LAG) because ports for a LAG may not be in close physical proximity but have to share bandwidth. Continuous efforts are being made to provide QOS for ports participating in LAGs.

Systems and methods for quality of service for link aggregation groups


A device (10) to transport sheets such as bank notes (30) comprises a rectangular tube (12) along which there is a flow of air F, the tube having pairs of independently addressable computer controlled flaps (14,16,18,20,22) on opposite internal walls. The pairs of flaps are controlled to project into the tube so as to reduce its height, and cause a local Venturi effect; by operating one or more pairs of flaps at a time in sequence, the Venturi effect moves along the tube, carrying the bank note by a surfing action.

This invention relates to a device for transporting sheets, for example paper sheets such as bank notes. One application of a sheet transport device is in an automated teller machine (ATM) in which bank notes are kept in a secure central store, and are supplied to the ATM on demand. Since the ATM then does not hold cash, it is no longer a target for robbery.
Previously proposed arrangements for supplying bank notes from a central store include mobile robots or guided vehicles, which are expensive and open to attack. Pneumatic tubes have been used, but require a piston-like carrier which must be loaded and unloaded with bank notes, a complex operation.


A biological photometric device includes a light irradiating unit for irradiating an object to be examined with light having a predetermined wavelength and sympathizing with oxygenated hemoglobin and deoxygenated hemoglobin through an optical fiber, a light detecting unit for detecting and amplifying light passing through a detecting optical fiber and the object as detected signals, a signal processing unit adapted for computing hemoglobin time change information based on oxygenated hemoglobin, deoxygenated hemoglobin and total hemoglobin in the object from the detected signals light detecting unit, and including a noise detector for arithmetically processing the detected signals and determining/detecting whether the time change information is noise attributed to the presence of obstacles to passing of light between the object and the end face of the optical fiber or noise attributed to the damage to the light irradiating unit, and a display unit for displaying the noise signals.

A biological photometric device is capable of measuring blood circulation, hemodynamics or variation of hemoglobin quantity in a living body in a simple manner without much restriction or any harm to the body, by irradiating light within the range from a visible light to infrared light to the living body of an object to be examined, and detecting the reflected light and scattered light passed inside of the living body.
The biological photometric device is used, for example, when a head region is the subject for measurement, for identifying activated state of the brain due to hemoglobin alteration in blood inflowing in a blood vessel in the brain upon physiological stimulation being imparted, or local focus of epileptic seizure, etc.
In Non-patent Document 1, measurement of hemoglobin alteration in a brain upon performing motion/language task, by cerebral blood flow mapping method using near infrared ray is reported. According to the report, it is disclosed that hemoglobin increment in the brain acquired by physiological stimulation such as motion/language task performance is only 5% at the most. This is also confirmed by other measurement methods such as PET (Positron-Emission Tomography).
While variation of hemoglobin amount in the brain due to physiological stimulation amounts to 5% at the most, noise signals measured by a biological photometric device often turn out to be a considerably large value of more than 50% when they are converted into the amount of hemoglobin variation in the brain. Hardly any signals indicating the amount variation of blood accompanying brain function activities are included in these noise signals, and they become a major diagnostic impediment.
In Patent Document 1, a method is described for detecting and eliminating spiky noise signals attributed to gaps generated in the very short period of time between an object and an aperture of optical fibers (hereinafter referred to as spike noise signals) by factors such as displacement of the applied light irradiating unit and light detecting unit. Discrimination between spike noise signals and normal signals is performed by determining whether derivative value of signal intensity is more than a predetermined threshold value or not.
Patent Document 1: WO 03/002004
Non-Patent Document 1: CLINICAL NEUROSCIENCE Vol. 17, No. 11, 1999-11


A carton for housing sheets, particularly dryer sheets. The dryer sheets are preferably stacked in a "U" shape and are removed via an access flap which may include 2 hinges and may be reclosable. The ratio of the length of the horizontal axis of the access flap is preferably of a defined ratio to the width of the sheet.

One method of applying fabric softener to clothes utilizes sheets impregnated with fabric softening materials. These sheets may be readily placed in the dryer with the clothes. During drying the fabric softening actives and optionally other materials, such as perfumes, are transferred to the clothes.
Previously, fabric softener sheets have generally been provided to consumers in the form of a roll. Individual sheets are formed by separating the sheets from the roll at lines of weakness provided at intervals along the roll. Perforations do not always perform reliably to give a clean separation with exertion of minimal force, particularly where the sheet is sufficiently durable to survive the temperatures and tumbling action of a clothes dryer.
Additional problems associated with the use of dryer sheets include the escape of fragrance from the carton prior to use.
Sheets of various shapes are known for use in household products. Individually folded dove tail sheets are known for products such as dusting cloths.

Lever Brothers Company, Division of Conopco, Inc.


The present invention relates to a non-invasive penile erection device having a constrictor ring designed to fit against the base of a male genital or penis, and a diaphragm seal that forms a substantially air tight seal against the constrictor ring. The constrictor ring is designed to comfortably and securely fit the base of the penis. The substantially air tight seal enables the pump to produce vacuum pressures of over 17 inches of mercury. The placement of the constrictor ring on the base of the penis and the greater vacuum pressure achieved by the device tend to draw the root of the penis into the constrictor ring so that a more natural erection is achieved and maintained after the vacuum tube is removed. The erection device can be easily provided as a kit containing a rigid vacuum tube, a hand or power operated pump, and several diaphragm seals and constrictor rings of various sizes to achieve a custom fit and optimum results.

A variety of non-invasive, vacuum type penile inflation devices are available. These inflation devices use external vacuum pressure to replace the body's natural ability to inflate the male genital or penis with blood. The devices typically utilize a cylindrically shaped vacuum tube for receiving the penis, a diaphragm for sealing the open end of the vacuum tube around the penis and a pump for evacuating or removing air from the vacuum tube. When air is removed from inside the tube, the decrease in pressure causes blood to enter and inflate the male genital. A constrictor ring is typically placed around the male genital after it is inflated to maintain the inflated state of the penis when the vacuum tube is removed. Examples of such devices are shown in U.S. Pat. No. 4,641,638 to Perry, U.S. Pat. No. 4,753,227 to Yanuck, Jr., U.S. Pat. No. 4,856,498 to Osbon, U.S. Pat. No. 5,125,890 to Merrill, and U.S. Pat. No. 5,344,389 to Walsdorf, the contents of which are incorporated by reference.
One shortcoming of conventional penile inflation devices is that the diaphragm does not form a sufficiently air tight seal to produce a desired amount of vacuum pressure inside the tube. Even when gel lubricants are applied to the diaphragm and male genital to improve the seal, air tends to leak between the diaphragm and the male genital. This air leakage reduces the amount of vacuum pressure attained inside the tube and the amount of inflation and stiffness of the male genital. Conventional penile inflation devices achieve about 14 to 16 inches of mercury of vacuum pressure, while a fully inflated, usable erection often requires about 17 to 22 inches of mercury of vacuum pressure.
An additional shortcoming with the prior art is that the inflation devices do not inflate and maintain the penis in an erect and usable position. Conventional constrictor rings are designed to fit on and secure to the substantially flat shaft portion of the penis. The rings are not intended to fit around the increasingly larger diametered base of the penis located adjacent the groin of the individual, especially when inflated. The increasingly wider base creates a slope that causes the constrictor ring to slide off the base and onto the shaft of the penis. Conventional constrictor rings are also not designed to allow the root of the penis, which extends inwardly of the groin of the individual, to be drawn into the constrictor ring. When the vacuum tube is removed, only that portion of the shaft of the penis downstream of the constrictor ring remains inflated. The base and root of the penis remain or return to a flaccid state and the penis does not achieve and maintain a natural erect position.
A still further problem with the prior art is that the flaccid base and root portions of the penis upstream of the constrictor ring create a "joint" about which the inflated shaft portion of the penis may bend. The inflated portion of the penis must be manipulated by hand during use, which can be especially difficult for paraplegic and quadriplegic individuals or their partner.
A further problem of the prior art is that conventional constrictor rings used in various inflation devices are painful due to their narrow width and generally "rubber band" like shape. The edges of the constrictor ring dig into the skin of the individual and cause substantial pain.
A still further problem with conventional designs is that it is difficult to position the constrictor ring on the base or root of the male genital after it is placed on the penis. The user must grip the edges of the narrow rubber band shaped constrictor ring to adjust the constrictor ring and attempt to work it onto the base after its initial placement on the shaft of the penis. This can be quite difficult when the edges of the constrictor ring are digging into the skin.
A still further problem of conventional designs is that the lubricants used to help form the seal between the diaphragm and the male genital are messy. Lubricant invariably spreads all over the inflation device, the hands and body of the individual, and the surroundings.
A still further problem of the prior art is that the diaphragm and constrictor ring do not fit all individuals with equal comfort and equal results. Different individuals require differently sized constrictor rings and diaphragms. A trial and error approach to obtaining a correctly sized constrictor ring and diaphragm can be inconvenient and embarrassing given the nature of the product involved.
A still further problem with the prior art assemblies is that the manufacturing costs can be excessive. The cost and number of components making up the penile erection device should be kept to a minimum. The erection device should also cooperate with existing vacuum tube and pump designs when possible to avoid expensive and time consuming manufacturing modifications.
The present invention is provided to solve these and other problems.


An apparatus for aerobic biological treatment of aqueous organic wastes, which enables the achievement of a reduction of the amount of excess sludge, a stable quality of the treated water and an improved sedimentation performance of the biosludge while reducing the area of installation site and construction investment using a smaller apparatus; which apparatus comprises. a first aeration tank for mixing the aqueous organic waste with an activated sludge and aerating the resulting mixture; a solid/liquid separation unit; a modification unit for modifying a part of the separated sludge so as to render it easily biodegradable; and a second aeration tank for aerating the modified sludge and a return sludge and means for returning the sludge to said first aeration tank.

In an aerobic biological treatment of aqueous organic wastes by making use of the activity of aerobic microorganisms, such as the so-called activated sludge treatment, a large amount of "excess sludge" is formed, which is difficult to be disposed of. While heretofore such excess sludge has been disposed by depositing it in landfills, because landfills are becoming less available, it is now necessary to reduce the amount of excess sludge formed.
Japanese Patent Kokai JP-A-6-206088 discloses a technique for aerobic biological treatment of aqueous organic wastes in which a greater amount of the biosludge than the amount of that multiplied by an anabolic intake of the BOD components in the waste is extracted from the aerobic biological treatment system and is subjected to an ozone treatment before it is returned to the biological treatment system, the apparatus for which is illustrated in FIG. 4 in a flow diagram. In FIG. 4, numeral 1 represents the aerobic biological treatment system composed of an aeration tank 11 and a solid/liquid separation unit 12 and 2 is a modification treatment system. Over the bottom of the aeration tank 11 is disposed an air distributor 15, to which an air supply line 16 is connected. To the aeration tank 11, an aqueous waste supply line 17 and a biosludge return line 24 having a pump 23 are joined. The aeration tank 11 communicates to the solid/liquid separation unit 12 via a connection line 18. To the solid/liquid separation unit 12, a treated liquid line 21 and a separated sludge delivery line 22 are joined. The separated sludge delivery line 22 branches off into a sludge return line 24, a sludge extraction line 32 and an excess sludge delivery line 37.
The modification treatment system 2 functions to modify the biosludge to convert it into an easily biodegradable product by the ozonization and is provided with an ozonization vessel 31 connected, at its upper portion, with a sludge extraction line 32 guided from the solid/liquid separation unit 12 and a spent ozone discharge line 33 and, at its lower portion, with an ozone supply line 34 and an ozonized sludge delivery line 35. The ozonized sludge delivery line 35 communicates to the aeration tank 11. A pump 36 is provided in the sludge extraction line 32.
For effecting the aerobic biotreatment of an aqueous organic waste using the apparatus as shown in FIG. 4, the aqueous organic waste to be treated is guided first into the aeration tank 11 via the aqueous waste supply line 17 and is mixed therein with the return sludge from the sludge return line 24 and with the biosludge present in the aeration tank 11, while introducing therein atmospheric air through the air distributor 15 to effect an aerobic biological treatment. A part of the mixed liquor in the aeration tank 11 is guided to the solid/liquid separation unit 12 via the connection line 18 and is subjected to a solid/liquid separation into a separated liquid and a separated sludge. The separated liquid is exhausted out of the system via the treated liquid line 21, while a part of the separated sludge is returned as the return sludge to the aeration tank 11 via the sludge return line 24 and the other part is supplied as an extracted sludge to the ozonization vessel 31. If excess sludge occurs, it is discharged out of the system via the excess sludge delivery line 37.
In the modification treatment system 2, a part of the separated sludge is guided into the ozonization vessel 31 via the sludge extraction line 32. Ozone is supplied through ozone supply line 34 to cause it to contact with the extracted biosludge to effect ozonization. The living bacteria in the extracted biosludge will almost be destroyed thereby and the biosludge is modified into easily biodegradable BOD components of the aqueous waste. The ozonized sludge is recirculated from the ozonized sludge delivery line 35 to the aeration tank 11, where it is subjected to aerobic biotreatment. By subjecting the extracted biosludge to an ozone treatment and then to the aerobic biotreatment in this way, a reduction in the amount of excess sludge can be attained and even a complete elimination of occurrence of excess sludge may be realized when a greater amount of extracted biosludge than the amount of the biosludge multiplied in the aerobic biotreatment system is subjected to the ozone treatment in the modification system.
In the above-described prior technique, however, the average sludge retention time (SRT) in the aerobic biotreatment system with respect to the living bacteria becomes lower due to the annihilation of the bacteria upon the ozone treatment, as shown by the equation: EQU SRT of living bacteria=A/B (a)
in which A denotes the amount of biosludge retained in the aeration tank and B represents the amount of ozonized biosludge.
If, for example, the amount of excess sludge occurred is zero, about three times the amount of excess sludge obtained in a conventional activated sludge treatment should be extracted and subjected to the ozone treatment, so that the SRT of living bacteria herefor (below, the SRT of living bacteria is denoted by SRT') will be decreased to 1/3 of that in a conventional activated sludge treatment. Consequently, in the prior technique, insufficient biodegradation of organic matter may occur when the temperature of the aqueous waste is low, such as in winter, resulting in, for example, an instablility in the quality of the treated water and accumulation of undecomposed organic sludge in the flocs of biosludge which deteriorates the sedimenting property of the sludge in the aeration tank or in the solid/liquid separation tank.
Such problems may be avoided by installing further aeration units to reduce the load of the activated sludge, which, however, brings about increases in the installation site and construction investments accompanied by a greater economical restriction.

Apparatus for aerobic biological treatment of aqueous organic wastes


A DSSS system determines transmission reliability of a communication channel in real time. A DSSS transmitter (f0=1/T) generates a Pseudo Noise (PN) code and modulates a carrier source [cos. (2Σγc)] with a selected chip rate. The transmitter bandwidth is a direct function of the chip rate. The PN coded carrier signal is further modulated by a data signal [m(t)] to provide an output signal [s(t)] to a correlator via a communication channel for purposes of determining the transmission characteristic of the channel. The correlator running a variable length pseudo noise code combines the code and the carrier which relates the incoming data signal to a correlation value for detecting the data signal. The correlation value is compared to a threshold value based upon experience of reliable transmission of data through the communication channel. The value of the correlation value declines as the data is attenuated in the communication channel, thus, the band limiting effect of the communication can be determined by the change in the correlation value.

1. Field of Invention
This invention relates to communication systems, methods of operation and program products. More particularly, the invention relates to dynamic measurement of communication channel characteristics using direct sequence spread spectrum (DSSS) systems, methods and program products.
2. Description of Prior Art
A common problem in communication system is improving data transmission reliability between sending and receiving stations. Data transmissions are subject to bandwidth limitations, propagation impairments, noise and other factors. A communication channel which includes means to perform on-the-fly analysis to measure and adjust the channel characteristics for improved reliability would solve a long-standing problem in communication systems. One communication system which measures communication characteristics during transmission is a Direct Spread Spectrum System (DSSS) described in the text Wireless LANS: Implementing Interoperable networks by J. Geir, published by Macmillan Technical Publishing, 1999 at pages 47–49, 67–68 [(ISBN 98-85498)] (ISBN 1-57870-081-7). The measurement is taken for purposes of signal acquisition in synchronizing the Pseudo Noise (PN) codes at the sending and receiving stations. What is needed in the art is a DSSS system which enables the reliability of data transmission in a communication channel to be judged and the transmission adjusted accordingly for improved signal reliability.
Prior art related to DSSS communication systems includes:
(1) An article entitled "A New Serial Search Acquisition Approach With Automatic Decision Threshold Control" by S. Chung, published 1995 IEEE 45th Vehicular Technology Conference, V2, pages 530–536 discloses a CDMA signal acquisition system and uses, in each dwell, an adaptive signal threshold for signal detection and an adaptive signal classification threshold for classifying a signal versus noise. The system uses the detected signal and noise statistics to estimate SNR. The signal detection threshold is obtained from the maximum correlation value of the acquisition process. The signal classification threshold is derived from the average value of the signal detection threshold and noise estimate. If a new signal candidate is detected, both the signal detection threshold and the signal classification threshold are updated. As a result, the signal classification threshold is equivalent to the threshold used in the conventional serial acquisition system. The decision to stop or continue the acquisition search is aided by a pre-verification process.
(2) U.S. Pat. No. 6,052,408 issued Apr. 18, 2000 discloses improving the performance of a cellular communication system using direct sequence spread spectrum techniques. An apparatus and process enable dynamic modification of communication system parameters including PN code length, chipping rate and modulation technique for transmission of a data packet. Modification is based on proximity of the transmitter and receiver, noise level, transmitter and receiver capabilities and other factors. The system makes tradeoffs between data transmission speed and communication range to improve system performance.
(3) U.S. Pat. No. 5,732,111 issued Mar. 23, 1998 discloses a frequency error calibration, estimation and compensation device and method for direct sequence spread spectrum systems, such as digital cordless telephones having a handset and a base station. Initial frequency calibration occurs when the handset is physically coupled to the base station. The allowable frequency error range is divided into a plurality of frequency bins. Both the handset and base station transmit and receive messages using a predetermined frequency offset bin as an estimate of the frequency error. A signal quality value is determined and then a next bin is selected and a next signal quality value is determined. Once a signal quality value has been determined for each frequency bin, a communications link is established between the handset and the base station to allow automatic frequency control tracking to fine tune the frequency offset value. If the signal quality is not above a threshold value, the procedure is repeated. After system calibration, frequency error estimation is performed by cross product demodulation of the received in-phase and quadrature signals. The cross product output is limited and filtered. A phase rotator performs frequency compensation by multiplying the received in-phase and quadrature signals by (cos.phi.(t)+jsin.phi.(t)) where. phi.(t) is the sum of the current phase value and the limited and filtered cross product value.
None of the prior art discloses dynamic measurement of a communication channel using DSSS by extracting a PN code from a received signal using a correlator value and comparing the correlator value to a threshold where a correlator value below the threshold is indicative of unreliable communication in the channel and a correlator value above the threshold indicative of reliable transmission through the channel, the transmission characteristics of the signal being adjusted according to the correlator value—threshold comparison.

Dynamic measurement of communication channel characteristics using direct sequence spread spectrum (DSSS) systems, methods and program products


The present invention relates to an improved method for embossing and decorating a thermoplastic velvet-like fabric. A transfer sheet supporting a thermally-activated decoration is simultaneously passed with a fabric between two rolls which are under pressure with respect to each other. At least one of the rolls is engraved so as to cause embossing of the fabric. The passing of the fabric and transfer sheet between the rolls is carried out at a temperature sufficient to activate the decoration and allow the transfer of the decoration to the embossed portions of the fabric. The fabric may be heated prior to the embossing-decorating step so that the velvet-like pile is at least partially plasticized. The fabric is then brushed to erect the pile to an erect position. If the decorating is printing, the fabric may be heated immediately before and after the embossing/printing step to transfer a sufficient amount of dye, and to penetrate and seal the dye within the fabric.

This invention is directed to a method and apparatus for treating a fabric which is simultaneously embossed and decorated and, in particular, to a method and apparatus for treating a velvet-like fabric.
The process of embossing fabrics is known in the art. Embossed fabrics have raised or projected figures or designs in relief on fabric surfaces. Embossed surfaces are usually produced by passing the fabric through engraved, heated rolls under heavy pressure to give a raised effect. The fabric may be passed through two rolls, one of which is engraved and the other being smooth, or both rolls may be engraved in such a manner that when the rolls are synchronized, the indentations in one roll at the point of embossing cooperate with protuberances on the other roll.
The method of heat transfer printing is also well known in the art. This is a method of printing fabric made of polyester or other thermoplastic fibers with disperse dyes. The design is transferred from pre-printed paper onto the fabric by contact heat. Having no affinity for paper, the dyes are absorbed by the fabric. To complete the transfer, the preprinted paper must be in contact with the fabric for a sufficiently long residence time, i.e. the time during which the fabric is between the rolls, although the length of residence time may be reduced if the pressure on the preprinted paper and fabric is increased. The method is capable of producing well defined, clear prints.
Processes for simultaneously embossing and transfer printing to fabrics are known in the art as well. In U.S. Pat. No. 1,744,829 and U.S. Pat. No. 1,895,243, the simultaneous printing and embossing of cellulosic fabrics is disclosed. A transfer dye sheet and cellulosic fabric are simultaneously passed between one embossed and one smooth roll under high pressure with the transfer sheet passed through directly next to the engraved roll. No printing or embossing occurs at the portions of the fabric which pass between the smooth roll and the engraved portions of the engraved roll because the engraving is of a sufficient depth that the fabric does not contact the embossing roll at the engraved portions. Either the transfer printing sheet or the fabric is moistened prior to passing between the rolls. Both patents teach that heating the rolls increase the transferability of the dye in the transfer sheet to the fabric. The simultaneous transferring and embossing operation allows the printing to be transferred directly to the portion of the fabric which has been embossed, i.e., the portion of the fabric pressurized by the protuberances on the engraved roll.
The disadvantages of the apparatuses and methods taught by these patents is that they produce less than satisfactory results if the fabric to be embossed and decorated possesses depth, as in velvet-like fabrics, instead of ordinary flat woven and knit fabrics. Velvet-like fabrics and methods of producing them are known in the art. Velvet-like fabrics include a base and a surface region defined by a short, but usually dense, pile formed of fibers. Velvet-like fabrics may be knit, woven or flocked. For example, a woven velvet-like fabric may be made by producing a double-cloth structure woven face to face, with the pile ends interchanging between the two cloths. The two fabrics are cut apart by a traversing knife, producing two fabrics with a cut-pile surface. In another method, pile ends are lifted over cutting wires which are inserted in the same manner as the filling and the pile is cut as the wire is withdrawn.
Flock fabrics are another type of velvet-like fabrics which are produced by a process known as "flocking" in which adhesive is printed or coated on a fabric, and finely cut fibers are either adhered to or embedded in the fabric by means of dusting, air-blasting or electrostatic attraction. The finely cut fibers remain adhered to or embedded in the fabric at those portions of the fabric which were printed and coated with adhesive. The result is a velvet-like fabric. In a variation known as flock printing, only selected portions of the fabric are printed or coated with adhesive and, after the finely cut fibers are adhered to or embedded in the fabric, the fibers not secured by adhesive are removed by mechanical action.
In simultaneously embossing and decorating a pile fabric such as a velvet-like fabric, the fiber ends not attached to the fabric base, or embedded in the adhesive if the fabric is a flock fabric, may not be erect and so the fibers may be laying down prior to the embossing step, particularly if the fabric has been rolled-up. The contrast between the embossed and non-embossed portions will thus be reduced if the non-embossed portions are flat. Thus, a velvet-like fabric which is simply processed with the embossing and decorating methods taught in the prior art will have a less than satisfactory contrast in color and contour between the embossed and non-embossed area.
Additionally, known methods for simultaneously embossing and decorating are less than completely satisfactory if the fabric is a thermoplastic fabric and the decorating step is transfer printing of dye. Thermoplastic fabrics are fabrics at least the surface region of which are essentially made from synthetic materials such as nylon, polyester and acrylic which soften or "plasticize" when heated. Such surface regions are capable of embossing by the application of heat and pressure. One problem with known methods is due to the limited residence time of the fabric between the rolls during the step of embossing and printing. Not enough dye may be transferred to the fabric since the residence time may be insufficient to heat the fabric and pre-printed paper to the required temperature and transfer enough dye to the fabric. Yet another problem is that thermoplastic fabrics do not "soak up" dyes readily in the transfer printing process when the time to transfer the dye is brief, and much of the dye will rub off the fabric after the simultaneous step of embossing and printing.
Accordingly, a method and apparatus for simultaneously embossing and decorating a thermoplastic velvet-like fabric which overcomes the problems outlined above is desired.

Method for treating velvet-like fabric which is simultaneously embossed and decorated


In an optical data bus for a vehicle with transmit/receive units (TRUs) that exchange data messages over optical connecting lines and are supplied with electrical energy, the receiving TRU can be deactivated to reduce energy consumption and then reactivated for a short time. The transmitting TRU emits a light pulse whose length is greater than the duration of its resting phase.

This application claims the priority of German Application No. 198 33 613.6, filed Jul. 25, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an optical data bus for a vehicle with transmit/receiving units that exchange data messages over optical connecting lines and which are supplied with electrical energy.
Such data buses are becoming increasingly important in vehicles. Even when the vehicle is parked, the TRUs must be at least partially ready to receive. For this purpose, at least the optical receiver, a phototransistor for example, must be supplied with operating voltage. A current of several mA then flows. Added together, these currents, admittedly small individually, produce a high power draw through a large number of receivers when the vehicle is parked.
The goal of the invention is to provide a data bus of the type recited at the outset that has a low power draw when the vehicle is parked, but in which operating readiness is simultaneously guaranteed.
The invention achieves this goal by providing an optical data bus for a vehicle with transmit/receive units (TRUs) that exchange data messages over optical connecting lines and which are supplied with electrical energy. The invention is characterized in that the receiving TRU can be deactivated to reduce energy consumption and then reactivated for a short time. Further, the transmitting TRU emits a light pulse whose length is greater than the length of its resting phase.
The activation of the receiving units, each only for a short time, produces a definite reduction in the energy requirement. This requirement is only a fraction of that during continuous operation. The fraction is determined by the cycle ratio, in other words the ratio of the ON times to the OFF times. For example, if the cycle ratio is 1:1000, the power requirement is reduced practically to a thousandth, since the current draw of the electronic parts that produce the cyclic operation of the receiver is negligible in this technology.
The operational readiness of the data bus is ensured at all times. The individual TRUs are activated over the optical connecting lines. Additional or alternative activation by the electrical power supply is not necessary.
Advantageous embodiments of the invention are described herein. One of the problems which the invention overcomes concerns the time interval or frequency with which the individual TRUs are activated. One possibility is to activate the TRUs briefly at regular intervals. The advantage of this is that the transmitting TRUs each must emit only light pulses of a constant length.
On the other hand, a further reduction of the power consumption can be achieved when the resting phases are kept as long as possible. For example, they can depend on how long the vehicle has already been parked and can be lengthened in direct ratio to this time. This however creates the necessity for varying the length of the light pulses.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Bayerische Motoren Werke Aktiengesellschaft


A method of producing nanoparticles comprises effecting conversion of a nanoparticle precursor composition to the material of the nanoparticles. The precursor composition comprises a first precursor species containing a first ion to be incorporated into the growing nanoparticles and a separate second precursor species containing a second ion to be incorporated into the growing nanoparticles. The conversion is effected in the presence of a molecular cluster compound under conditions permitting seeding and growth of the nanoparticles.

There has been substantial interest in the preparation and characterization, because of their optical, electronic and chemical properties, of compound semiconductors consisting of particles with dimensions in the order of 2-100 nm,1-8 often referred to as quantum dots and/or nanocrystals. These studies have occurred mainly due to their size-tunable electronic, optical and chemical properties and the need for the further miniaturization of both optical and electronic devices9,10 that now range from commercial applications as diverse as biological labeling, solar cells, catalysis, biological imaging, light-emitting diodes amongst many new and emerging applications.
Although some earlier examples appear in the literature,11 recently methods have been developed from reproducible "bottom up" techniques, whereby particles are prepared atom-by-atom, i.e. from molecules to clusters to particles using "wet" chemical procedures.12, 13 Rather, from "top down" techniques involving the milling of solids to finer and finer powders.
To-date the most studied and prepared of semiconductor materials have been the chalcogenides II-VI materials namely ZnS, ZnSe, CdS, CdSe, CdTe; most noticeably CdSe due to its tuneability over the visible region of the spectrum. As mentioned semiconductor nanoparticles are of academic and commercial interest due to their differing and unique properties from those of the same material, but in the macro crystalline bulk form. Two fundamental factors, both related to the size of the individual nanoparticle, are responsible for their unique properties. The first is the large surface to volume ratio; as a particle becomes smaller, the ratio of the number of surface atoms to those in the interior increases. This leads to the surface properties playing an important role in the overall properties of the material. The second factor is that, with semiconductor nanoparticles, there is a change in the electronic properties of the material with size, moreover, the band gap gradually becoming larger because of quantum confinement effects as the size of the particles decreases. This effect is a consequence of the confinement of an 'electron in a box' giving rise to discrete energy levels similar to those observed in atoms and molecules, rather than a continuous band as in the corresponding bulk semiconductor material. Thus, for a semiconductor nanoparticle, because of the physical parameters, the "electron and hole", produced by the absorption of electromagnetic radiation, a photon, with energy greater than the first excitonic transition, are closer together than in the corresponding nacrocrystalline material, so that the Coulombic interaction cannot be neglected. This leads to a narrow bandwidth emission, which is dependent upon the particle size and composition. Thus, quantum dots have higher kinetic energy than the corresponding nacrocrystalline material and consequently the first excitonic transition (band gap) increases in energy with decreasing particle diameter.
Single core nanoparticles, which consist of a single semiconductor material along with an outer organic passivating layer, tend to have relatively low quantum efficiencies due to electron-hole recombination occurring at defects and daggling bonds situated on the nanoparticle surface which lead to non-radiative electron-hole recombination. One method to eliminate defects and daggling bonds is to grow a second material, having a wider band-gap and small lattice mismatch with the core material, epitaxially on the surface of the core particle, (e.g. another II-VI material) to produce a "core-shell particle". Core-shell particles separate any carriers confined in the core from surface states that would otherwise act as non-radiative recombination centers. One example is ZnS grown on the surface of CdSe cores. The shell is generally a material with a wider bandgap then the core material and with little lattice mismatch to that of the core material, so that the interface between the two materials has as little lattice strain as possible. Excessive strain can further result in defects and non-radiative electron-hole recombination resulting in low quantum efficiencies.
However, the growth of more than a few mono layers of shell material can have the reverse effect thus; the lattice mismatch between CdSe and ZnS, is large enough that in a core-shell structure only a few monolayers of ZnS can be grown before a reduction of the quantum yield is observed, indicative of the formation of defects due to breakdown in the lattice as a result of high latticed strain. Another approach is to prepare a core-multi shell structure where the "electron-hole" pair is completely confined to a single shell such as the quantum dot-quantum well structure. Here, the core is of a wide bandgap material, followed by a thin shell of narrower bandgap material, and capped with a further wide bandgap layer, such as CdS/HgS/Cds grown using a substitution of Hg for Cd on the surface of the core nanocrystal to deposit just 1 monolayer of HgS.14 The resulting structures exhibited clear confinement of photoexcited carriers in the HgS layer.
The coordination about the final inorganic surface atoms in any core, core-shell or core-multi shell nanoparticles is incomplete, with highly reactive "daggling bonds" on the surface, which can lead to particle agglomeration. This problem is overcome by passivating (capping) the "bare" surface atoms with protecting organic groups. The capping or passivating of particles not only prevents particle agglomeration from occurring, it also protects the particle from its surrounding chemical environment, along with providing electronic stabilization (passivation) to the particles in the case of core material. The capping agent usually takes the form of a Lewis base compound covalently bound to surface metal atoms of the outer most inorganic layer of the particle, but more recently, so as to incorporate the particle into a composite, an organic system or biological system can take the form of, an organic polymer forming a sheaf around the particle with chemical functional groups for further chemical synthesis, or an organic group bonded directly to the surface of the particle with chemical functional groups for further chemical synthesis.
Many synthetic methods for the preparation of semiconductor nanoparticles have been reported, early routes applied conventional colloidal aqueous chemistry, with more recent methods involving the kinetically controlled precipitation of nanocrystallites, using organometallic compounds.
Over the past six years the important issues have concerned the synthesis of high quality semiconductor nanoparticles in terms of uniform shape, size distribution and quantum efficiencies. This has led to a number of methods that can routinely produce semiconductor nanoparticles, with monodispersity of <5% with quantum yields >50%. Most of these methods are based on the original "nucleation and growth" method described by Murray, Norris and Bawendi,15 but use other precursors that the organometallic ones used. Murray et at originally used organometallic solutions of metal-alkyls (R2M) M=Cd, Zn, Te; R=Me, Et and tri-n-octylphosphine sulfide/selenide (TOPS/Se) dissolved in tri-n-octylphosphine (TOP). These precursor solutions are injected into hot tri-n-octylphosphine oxide (TOPO) in the temperature range 120-400° C. depending on the material being produced. This produces TOPO coated/capped semiconductor nanoparticles of II-VI material. The size of the particles is controlled by the temperature, concentration of precursor used and length of time at which the synthesis is undertaken, with larger particles being obtained at higher temperatures, higher precursor concentrations and prolonged reaction times. This organometallic route has advantages over other synthetic methods, including near monodispersity<5% and high particle cystallinity. As mentioned, many variations of this method have now appeared in the literature which routinely give high quality core and core-shell nanoparticles with monodispersity of <5% and quantum yield >50% (for core-shell particles of as-prepared solutions), with many methods displaying a high degree of size16 and shape17 control.
Recently attention has focused on the use of "greener"554 precursors which are less exotic and less expensive but not necessary more environmentally friendly. Some of these new precursors include the oxides, CdO;18 carbonates MCO3 M=Cd, Zn; acetates M(CH3CO2)2 M=Cd, Zn and acetylacetanates [CH3COCH═C(O−)CH3]2 M=Cd, Zn; amongst other.19, 20 The use of the term "greener" precursors in semiconductor particle synthesis has generally taken on the meaning of cheaper, readily available and easier to handle precursor starting materials, than the originally used organometallics which are volatile and air and moisture sensitive, and does not necessary mean that "greener precursors" are any more environmentally friendly).
Single-source precursors have also proved useful in the synthesis of semiconductor nanoparticle materials of II-VI, as well as other compound semiconductor nanoparticles. Bis(dialkyldithio-/diseleno-carbamato)cadmium(II)/zinc(II) compounds, M(E2CNR2)2 (M=Zn or Cd, E=S or Se and R=alkyl), have used a similar 'one-pot' synthetic procedure, which involved dissolving the precursor in tri-n-octylphosphine (TOP) followed by rapid injection into hot tri-n-octylphosphine oxide/tri-n-octylphosphine (TOPO/TOP) above 200° C.
For all the above methods rapid particle nucleation followed by slow particle growth is essential for a narrow particle size distribution. All these synthetic methods are based on the original organometallic "nucleation and growth" method by Murray et al15 which involves the rapid injection of the precursors into a hot solution of a Lewis base coordinating solvent (capping agent) which may also contain one of the precursors. The addition of the cooler solution subsequently lowers the reaction temperature and assist particle growth but inhibits further nucleation. The temperature is then maintained for a period of time, with the size of the resulting particles depending on reaction time, temperature and ratio of capping agent to precursor used. The resulting solution is cooled followed by the addition of an excess of a polar solvent (methanol or ethanol or sometimes acetone) to produce a precipitate of the particles that can be isolated by filtration or centrifugation.
Due to their increased covalent nature III-V and IV-VI highly crystalline semiconductor nanoparticles are more difficult to prepare and much longer annealing time are usually required. However, there are now many reports15 II-VI and IV-VI materials being prepared by a similar procedure GaN,21 GaP,22 GaAs,22, 23, 24, 25, 26, InP27, 28, 29 InAs30, 27 and for PbS31 and PbSe.32
Fundamentally all these preparations rely on the principle of particle nucleation followed by growth, moreover, to have a monodisperse ensemble of nanoparticles there must be proper separation of nanoparticles nucleation from nanoparticle growth. This is achieved by rapid injection of one or both precursors into a hot coordinating solvent (containing the other precursor if otherwise not present) which initiates particles nucleation, however, the sudden addition of the cooler solution upon injection subsequently lowers the reaction temperature (the volume of solution added is about ⅓ of the total solution) and inhibits further nucleation maintaining a narrow nanoparticle size distribution. Particle growth being a surface catalyzes process or via Ostwald ripening, depending on the precursor's used33, continues at the lower temperature and thus nucleation and growth are separated. This method works well for small scale synthesis where one solution can be added rapidly to another while keeping a homogenous temperature throughout the reaction. However, on larger preparative scale whereby large volumes of solution are required to be rapidly injected into one another a temperature differential can occur within the reaction which can subsequently lead to a large particle size distribution.
Preparation from single-source molecular clusters, Cooney and co-workers used the cluster [S4Cd10(SPh)16] [Me3NH]4 to produce nanoparticles of CdS via the oxidation of surface-capping SPh− ligands by iodine. This route followed the fragmentation of the majority of clusters into ions which were consumed by the remaining [S4Cd10(SPh)16]4− clusters which subsequently grow into nanoparticles of CdS.34
Strouse35 and co-workers used a similar synthetic approach but employed thermolysis (lyothermal) rather than a chemical agent to initiate particle growth. Moreover, the single-source precursors [M10Se4(SPh)16][X]4 X═Li+ or (CH3)3NH+, M=Cd or Zn were thermolysised whereby fragmentation of some clusters occurs followed by growth of other from scavenging of the free M and Se ions or simply from clusters aggregating to form larger clusters and then small nanoparticles which subsequently continue to grow into larger particles.
According to the present invention there is provided a method of producing nanoparticles comprising effecting conversion of a nanoparticle precursor composition to the material of the nanoparticles, said precursor composition comprising a first precursor species containing a first ion to be incorporated into the growing nanoparticles and a separate second precursor species containing a second ion to be incorporated into the growing nanoparticles, wherein said conversion is effected in the presence of a molecular cluster compound under conditions permitting seeding and growth of the nanoparticles.
The present invention relates to a method of producing nanoparticles of any desirable form and allows ready production of a monodisperse population of such particles which are consequently of a high purity. It is envisaged that the invention is suitable for producing nanoparticles of any particular size, shape or chemical composition. A nanoparticle may have a size falling within the range 2-100 nm. A sub-class of nanoparticles of particular interest is that relating to compound semiconductor particles, also known as quantum dots or nanocrystals.
An important feature of the invention is that conversion of the precursor composition (comprising separate first and second precursor species) to the nanoparticles is effected in the presence of a molecular cluster compound (which will be other than the first or second precursor species). Without wishing to be bound by any particular theory, one possible mechanism by which nanoparticle growth may take place is that each identical molecule of the cluster compound acts as a seed or nucleation point upon which nanoparticle growth can be initiated. In this way, nanoparticle nucleation is not necessary to initiate nanoparticle growth because suitable nucleation sites are already provided in the system by the molecular clusters. The molecules of the cluster compound act as a template to direct nanoparticle growth. 'Molecular cluster' is a term which is widely understood in the relevant technical field but for the sake of clarity should be understood herein to relate to clusters of 3 or more metal or non-metal atoms and their associated ligands of sufficiently well-defined chemical structure such that all molecules of the cluster compound possess the same relative molecular mass. Thus the molecular clusters are identical to one another in the same way that one H2O molecule is identical to another H2O molecule. The use of the molecular cluster compound provides a population of nanoparticles that is essentially monodisperse. By providing nucleation sites which are so much more well defined than the nucleation sites employed in previous work the nanoparticles formed using the method of the present invention possess a significantly more well defined final structure than those obtained using previous methods. A further significant advantage of the method of the present invention is that it can be more easily scaled-up for use in industry than current methods. Methods of producing suitable molecular cluster compounds are known within the art, examples of which can be found at the Cambridge Crystallographic Data Centre (www.ccdc.ca.ac.uk).
The conversion of the precursor composition to nanoparticle is carried out under conditions to ensure that there is either direct reaction and growth between the precursor composition and cluster, or some clusters grow at the expense of others, due to Ostwald ripening, until reaching a certain size at which there is direct growth between the nanoparticle and the precursor composition. Such conditions ensure that the monodispersity of the cluster compound is maintained throughout nanoparticle growth which, in turn, ensures that a monodisperse population of nanoparticles is obtained.
Any suitable molar ratio of the molecular cluster compound to first and second nanoparticle precursors may be used depending upon the structure, size and composition of the nanoparticles being formed, as well as the nature and concentration of the other reagents, such as the nanoparticle precursor(s), capping agent, size-directing compound and solvent. It has been found that particularly useful ratios of the number of moles of cluster compound compared to the total number of moles of the first and second precursor species preferably lie in the range 0.0001-0.1 (no. moles of cluster compound): 1 (total no. moles of first and second precursor species), more preferably 0.001-0.1:1, yet more preferably 0.001-0.060:1. Further preferred ratios of the number of moles of cluster compound compared to the total number of moles of the first and second precursor species lie in the range 0.002-0.030:1, and more preferably 0.003-0.020:1. In particular, it is preferred that the ratio of the number of moles of cluster compound compared to the total number of moles of the first and second precursor species lies in the range 0.0035-0.0045:1.
It is envisaged that any suitable molar ratio of the first precursor species compared to the second precursor species may be used. For example, the molar ratio of the first precursor species compared to the second precursor species may lie in the range 100-1 (first precursor species):1 (second precursor species), more preferably 50-1:1. Further preferred ranges of the molar ratio of the first precursor species compared to the second precursor species lie in the range 40-5:1, more preferably 30-10:1. In certain applications it is preferred that approximately equal molar amounts of the first and second precursor species are used in the method of the invention. The molar ratio of the first precursor species compared to the second precursor species preferably lies in the range 0.1-1.2:1, more preferably, 0.9-1.1:1, and most preferably 1:1. In other applications, it may be appropriate to use approximately twice the number of moles of one precursor species compared to the other precursor species. Thus the molar ratio of the first precursor species compared to the second precursor species may lie in the range 0.4-0.6:1, more preferably the molar ratio of the first precursor species compared to the second precursor species is 0.5:1. It is to be understood that the above precursor molar ratios may be reversed such that they relate to the molar ratio of the second precursor species compared to the first precursor species. Accordingly, the molar ratio of the second precursor species compared to the first precursor species may lie in the range 100-1 (second precursor species): 1 (first precursor species), more preferably 50-1:1,40-5:1, or 30-10:1. Furthermore, the molar ratio of the second precursor species compared to the first precursor species may lie in the range 0.1-1.2:1,0.9-1.1:1,0.4-0.6:1, or may be 0.5:1.
The method of the present invention concerns the conversion of a nanoparticle precursor composition to a desired nanoparticle. Suitable precursor compositions comprise two or more separate precursor species each of which contains at least one ion to be included in the growing nanoparticle. The total amount of precursor composition required to form the final desired yield of nanoparticles can be added before nanoparticle growth has begun, or alternatively, the precursor composition can be added in stages throughout the reaction.
The conversion of the precursor composition to the material of the nanoparticles can be conducted in any suitable solvent. In the method of the present invention it is important to ensure that when the cluster compound and precursor composition are introduced in to the solvent the temperature of the solvent is sufficiently high to ensure satisfactory dissolution and mixing of the cluster compound and precursor composition. Once the cluster compound and precursor composition are sufficiently well dissolved in the solvent the temperature of the solution thus formed is raised to a temperature, or range of temperatures, which is/are sufficiently high to initiate nanoparticle growth. The temperature of the solution can then be maintained at this temperature or within this temperature range for as long as required to form nanoparticles possessing the desired properties.
A wide range of appropriate solvents are available. The particular solvent used is usually at least partly dependent upon the nature of the reacting species, i.e. precursor composition and/or cluster compound, and/or the type of nanoparticles which are to be formed. Typical solvents include Lewis base type coordinating solvents, such as a phosphine (e.g. TOP), a phosphine oxide (e.g. TOPO) or an amine (e.g. HDA), or non-coordinating organic solvents, e.g. alkanes and alkenes. If a non-coordinating solvent is used then it will usually be used in the presence of a further coordinating agent to act as a capping agent for the following reason.
If the nanoparticles being formed are intended to function as quantum dots it is important to ensure that any dangling bonds on the surface of the nanoparticles are capped to minimize non-radiative electron-hole recombination and inhibit particle agglomeration which can lower quantum efficiencies. A number of different coordinating solvents are known which can also act as capping or passivating agents, e.g. TOP, TOPO or HDA. If a solvent is chosen which cannot act as a capping agent then any desirable capping agent can be added to the reaction mixture during nanoparticle growth. Such capping agents are typically Lewis bases but a wide range of other agents are available, such as oleic acid and organic polymers which form protective sheaths around the nanoparticles.
A further way to avoid problems related to non-radiative electron-hole recombination is to grow one or more shells around the nanoparticle core to form a 'core-shell' nanoparticle. Such shells are well known in the art and are typically comprised of a different material to that of the core. The shell material is usually selected so as to have a wider band gap than the core material but to have as little lattice mismatch with the core as possible to minimize lattice strain at the core-shell interface which could lower quantum efficiencies due to non-radiative electron-hole recombination.
The progress of nanoparticle growth can be monitored in any convenient way, such as photoluminescence (PL) or UV-visible (UV-vis) spectroscopy. Once nanoparticles have been produced having the desired properties, e.g. when a nanoparticle peak is observed on the PL/UV-vis emission spectra at the desired wavelength, further growth is inhibited by altering the reaction conditions, e.g. reducing the temperature of the solution below that necessary to support nanoparticle growth. At this stage the nanoparticles can be isolated immediately from solution by any convenient means, such as precipitation, or allowed to anneal at a suitable temperature for any desirable amount of time, e.g. 10 minutes to 72 hours, to 'size-focus' via Ostwald ripening prior to isolation. Following initial isolation, the nanoparticle material may then be subject to one or more rounds of washing to provide a final product of high purity.
It is also envisaged that a shape directing compound, such as a phosphonic acid derivative, may be added to the reaction mixture to encourage the growing nanoparticles to adopt a particular shape, e.g. spheres, rods, disks, tetrapods or stars, which may be of use in particular applications.
The invention comprises of a method to produce nanoparticle materials mainly but not restricted to compound semiconductor nanoparticles from the use of molecular clusters, whereby the clusters are defined identical molecular entities, as compared to ensembles of small nanoparticles, which inherently lack the anonymous nature of molecular clusters. The invention consists of the use of molecular clusters as templates to seed the growth of nanoparticles, whereby other molecular sources "molecular feedstocks" are used to facilitate particle growth. These molecular feedstocks are a combination of separate precursors each containing one or more element/ion required within the as to be grown nanoparticles.
Type of System to be Made
The present invention is directed to the preparation of a number of nanoparticles materials and includes compound semiconductor particles otherwise referred to as quantum dots or nanocrystals, within the size range 2-100 nm and include core material comprising:—
IIA-VIB (2-16) material, consisting of a first element from group 2 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but are not restricted to:—MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe . . . .
IIB-VIB (12-16) material consisting of a first element from group 12 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material includes but are not restricted to:—ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe.
II-V material consisting of a first element from group 12 of the periodic table and a second element from group 15 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—Zn3P2, Zn3As2, Cd3P2, Cd3As2, Cd3N2, Zn3N2.
III-V material consisting of a first element from group 13 of the periodic table and a second element from group 15 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—BP, AlP, AlAs, AlSb; GaN, GaP, GaAs, GaSb; InN, InP, InAs, InSb, AlN, BN.
III-IV material consisting of a first element from group 13 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—B4C, Al4C3, Ga4C.
III-VI material consisting of a first element from group 13 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials. Nanoparticle material include but is not restricted to:—Al2S3, Al2Se3, Al2Te3, Ga2S3, Ga2Se3, GeTe; In2S3, In2Se3, Ga2Te3, In2Te3, InTe.
IV-VI material consisting of a first element from group 14 of the periodic table and a second element from group 16 of the periodic table, and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—PbS, PbSe, PbTe, Sb2Te3, SnS, SnSe, SnTe.
Nanoparticle material consisting of a first element from any group in the transition metal of the periodic table, and a second element from any group of the d-block elements of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—NiS, CrS, CuInS2.
By the term doped nanoparticle for the purposes of specifications and claims, refer to nanoparticles of the above and a dopant comprised of one or more main group or rare earth elements, this most often is a transition metal or rare earth element, such as but not limited to zinc sulfide with manganese, such as ZnS nanoparticles doped with Mn+.
Ternary Phase
By the term ternary phase nanoparticle for the purposes of specifications and claims, refer to nanoparticles of the above but a three component material. The three components are usually compositions of elements from the as mentioned groups Example being (ZnxCdx-1S)mLn nanocrystal (where L is a capping agent).
Quaternary Phase
By the term quaternary phase nanoparticle for the purposes of specifications and claims, refer to nanoparticles of the above but a four-component material. The four components are usually compositions of elements from the as mentioned groups Example being (ZnxCdx-1SySey-1)mLn nanocrystal (where L is a capping agent).
Solvothermal
By the term Solvothermal for the purposes of specifications and claims, refer to heating the reaction solution so as to initiate and sustain particle growth and can also take the meaning solvothermal, thermolysis, thermolsolvol, solution-pyrolysis, lyothermal.
Core-Shell and Core/Multi Shell Particles
The material used on any shell or subsequent numbers of shells grown onto the core particle in most cases will be of a similar lattice type material to the core material i.e. have close lattice match to the core material so that it can be epitaxially grown on to the core, but is not necessarily restricted to materials of this compatibility. The material used on any shell or subsequent numbers of shells grown on to the core present in most cases will have a wider bandgap then the core material but is not necessarily restricted to materials of this compatibility. The materials of any shell or subsequent numbers of shells grown on to the core can include material comprising of:—
IIA-VIB (2-16) material, consisting of a first element from group 2 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe.
IIB-VIB (12-16) material consisting of a first element from group 12 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe.
II-V material consisting of a first element from group 12 of the periodic table and a second element from group 15 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—Zn3P2, Zn3As2, Cd3P2, Cd3As2, Cd3N2, Zn3N2.
III-V material consisting of a first element from group 13 of the periodic table and a second element from group 15 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—BP, AlP, AlAs, AlSb; GaN, GaP, GaAs, GaSb; InN, InP, InAs, InSb, AlN, BN.
III-IV material consisting of a first element from group 13 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—B4C, Al4C3, Ga4C.
III-VI material consisting of a first element from group 13 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials. Nanoparticle material include but is not restricted to:—Al2S3, Al2Se3, Al2Te3, Ga2S3, Ga2Se3, In2S3, In2Se3, Ga2Te3, In2Te3.
IV-VI material consisting of a first element from group 14 of the periodic table and a second element from group 16 of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—PbS, PbSe, PbTe, Sb2Te3, SnS, SnSe, SnTe.
Nanoparticle material consisting of a first element from any group in the transition metal of the periodic table, and a second element from any group of the d-block elements of the periodic table and also including ternary and quaternary materials and doped materials. Nanoparticle material include but is not restricted to:—NiS, CrS, CuInS2.
Outer Most Particle Layer
Capping Agent
The outer most layer (capping agent) of organic material or sheath material is to inhibit particles aggregation and to protect the nanoparticle from the surrounding chemical environment and to provide a means of chemical linkage to other inorganic, organic or biological material. The capping agent can be the solvent that the nanoparticle preparation is undertaken in, and consists of a Lewis base compound whereby there is a lone pair of electrons that are capable of donor type coordination to the surface of the nanoparticle and can include mono- or multi-dentate ligands of the type but not restricted to:—phosphines (trioctylphosphine, triphenolphosphine, tbutylphosphine), phosphine oxides (trioctylphosphine oxide), alkyl-amine (hexadecylamine, octylamine), ary-amines, pyridines, and thiophenes.
The outer most layer (capping agent) can consist of a coordinated ligand that processes a functional group that can be used as a chemical linkage to other inorganic, organic or biological material such as but not restricted to:—mercaptofunctionalized amines or mercaptocarboxylic acids.
The outer most layer (capping agent) can consist of a coordinated ligand that processes a functional group that is polymerisable and can be used to form a polymer around the particle, polymerisable ligands such as but not limited to styrene functionalized amine, phosphine or phosphine oxide ligand.
Nanoparticle Shape
The shape of the nanoparticle is not restricted to a sphere and can consist of but not restricted to a rod, sphere, disk, tetrapod or star. The control of the shape of the nanoparticle is by the addition of a compound that will preferentially bind to a specific lattice plane of the growing particle and subsequently inhibit or slow particle growth in a specific direction. Example of compounds that can be added but is not restricted to include:—phosphonic acids (n-tetradecylphosphonic acid, hexylphoshonic acid, 1-decanesulfonic acid, 12-hydroxydodecanoic acid, n-octadecylphosphonic acid).
Description of Preparative Procedure
The current invention should lead to pure, monodisperse, nanocrystalline particles that are stabilized from particle aggregation and the surrounding chemical environment by an organic layer, where M and E are two different elements in a (ME)nLy particles and L being the coordinating organic layer/capping agent, such as a II-VI semiconductor (ZnS)n(TOPO)y nanoparticle constituting of a ZnS core surrounded by trioctylphosphine oxide ligands (TOPO).
The first step for preparing nanoparticles of a semiconductor material is to use a molecular cluster as a template to seed the growth of nanoparticles from other element source precursors. This is achieved by mixing small quantity of a cluster which is to be used as the template with a high boiling solvent which can also be the capping agent, being a Lewis base coordination compound such as but not restricted to a phosphine, a phosphine oxide or an amine such as TOP, TOPO or HDA; or an inert solvent such as a alkane (octadecence) with the addition of a capping agent compound such as oleic acid. Further to this a source for M and a source for E (for a ME particle) are added to the reaction mixture. The M and E precursor are in the form of two separate precursors one containing M and the other containing E.
Further to this other regents mayor may not be added to the reactions which have the ability to control the shape of the nanoparticles grown. These additives are in the form of a compound that can preferentially bind to a specific face (lattice plane) of the growing nanoparticle and thus inhibit or slow grow along that specific direction of the particle. Other element source precursors may or may not be added to the reaction so as to produce ternary, quaternary or doped particles.
Initially, the compounds of the reaction mixture are allowed to mix on a molecular level at a low enough temperature where no particle growth will occur. The reaction mixture is then heated at a steady rate until particle growth is initiated upon the surfaces of the molecular cluster-templates. At an appropriate temperature after the initiation of particle growth further quantities of M and E precursors may be added to the reaction mixture if needed so as to inhibit particles consuming one another by the process of Ostwald ripening. Further precursor addition can be in the form of batch addition whereby solid precursor or solutions containing precursor are added over a period of time or by continuous dropwise addition. Because of the complete separation of particle nucleation and growth, the current invention displays a high degree of control in terms of particle size, which is controlled by the temperature of the reaction and concentrations of precursors present. Once the desired particle size is obtained, as established from UV and/or PL spectra of the reaction solution either by an in situ optical probe or from aliquots of the reaction solution, the temperature may or may not be reduced by ca. 30-40° C. and the mixture left to "size-focus" for a period of time being from 10 minutes to 72 hours.
Further consecutive treatment of the as formed nanoparticles to form core-shell or core-multi shell particles may be undertaken. Core-shell particle preparation is undertaken either before or after nanoparticle isolation, whereby the nanoparticles are isolated from the reaction and redissolved in new (clean) capping agent as this results in a better quantum yield. A source for N and a source for Y precursor are added to the reaction mixture and can be either in the form of two separate precursors one containing N and the other containing Y or as a single-source precursor that contains both N and Y within a single molecule to form a core-shell particle of ME/NY core shell material.
The process may be repeated with the appropriate element precursors until the desired core-multi shell material is formed. The nanoparticles size and size distribution in an ensemble of particles is dependent by the growth time, temperature and concentrations of reactants in solution, with higher temperatures producing larger nanoparticles.
Type of Cluster Used for Seeding
The invention includes the use of molecular clusters, whereby the clusters used are identical molecular entities as compared to nanoparticles, which inherently lack the anonymous nature of molecular clusters in an assembly. The clusters act as "embryo-type" templates for the growth of nanoparticles whereby other molecular sources precursors contribute ions to the growth process and thus clusters subsequently grow into particles. The molecular clusters to be used can consist of:—
Both elements required within the as to be grown nanoparticle either with or without other elements present plus organic moieties;
One element required within the as to be grown nanoparticle either with or without other elements present plus organic moieties;
Neither element required within the as to be grown nanoparticle either with or without other elements present plus organic moieties;
The requirement of a cluster used, is to initiate particle growth either via consumption of other clusters or from reaction with the precursors present. Thus, the cluster can be used as a template for particle growth.
Examples, clusters to be used but not restricted to include:—
IIB-VIB:—[{(PPh3)Hg}4(SPh)6]: (Ph4Ph)2(SEt)5(Br)(HgBr)4]: (Ph4P)2Hg4(SEt)5Br]: [Hg4Te12] [N(CH2CH2Et)4]4
IIB-VIB:—[Et3NH]4[Cd10Se4(SPh)16]; [RMEtBu]5 M=Zn, Cd, Hg; E=S, Se, Te; R=Me, Et, Ph: [X]4[E4M10(SR)16] E=S, Se, Te, M=Zn, Cd, Hg; X=Me3NH+, Li+, Et3NH+: [Cd32S14(SPh)36]L: [Hg10Se4(SePh)(PPh2nPr)4]; [Hg32Se14(SePh)36]; [Cd10Se4(SePh)12(PPr3)4]; [Cd32Se14(SePh)36(PPh3)4]; [M4(SPh)12]+[X]2 M=Zn, Cd, Hg; X=Me4N+, Li+: [Zn(SEt)Et]10: [MeMEiPr] M=Zn, Cd, Hg; E=S, Se, Te: [RCdSR′]5 R′═O(CIO3), R′═PPh3, iPr: [Cd10E4(E′Ph)12PR3)4] E, E′=Te, Se, S: [Cd8Se(SePh)12Cl4]2−: [M4Te12]4− M=Cd, Hg: [Ph12M18Cd10(PEt3)3] M=Te, Se:
II-V:—[RCdNR′]4 R═Cl, Br, I, PEt3, C═CSMe3; R′=PEt3, I: [RCdNR′]5 R=alkyl or aryl group and R′=alkyl or aryl group: [{RZn}6{PR′}4] R═I, Pet2Ph, R′=SiMe3: [M4Cl4(PPh2)4(PnPr3)2] M=Zn, Cd: [Li(thf)4]2[(Ph2P)10Cd4]: [Zn4(PPh2)4CI4(PRR2′)2] PRR′2═PMenPr2, PnBu3, PEt2Ph: [Zn4(PtBu2)4Cl4]
III-V [EtGaNEt]6; [MeGaN(4-C6H4F)]6; (MeGaNiBu)6; [RAlNR′]4 R=Me, CH2Pri, Ph; R′═Pri, CH2Pri, C6H2Me3; [(SiPri3)3AsAlH]6; [iPrNAlH]4; [RAlNR′]6 R=Me, Et, Cl, CH2Ph, CH2Pri, Ph; R′=Me H, Br, C═CPh, Pri, (CH2)2Me, (CH2)2NMe2, SiPh3: [CH3Ga—NCH2CH(CH3)2]6: [MeGaNiBu]6 [RGaNR′]4 R═Ph, Me; R′=Ph, C6F5, SiMe3, tBu: [EtGaNEt]6 [RGaPR′]4 R═iPr, C6H2Me3; R′=tBu: C6H2Me3: [RNInR′]4 R═Cl, Br, I, Me; R′=tBu, C6F5, C6H4F: [RInPR′]4 R═iPr, C6H2Me3, Et; R′═SiPh3, C6H2Me3, SiiPr3: [RInPR′]6 R=Et, R′═SiMe2(CMe2iPr)
III-VI [(tBu)GaSe]4; [tBuGaS]7; [RInSe]4 R=tBu, CMe2Et, Si(tBu)3, C((SiMe3)3)3; [RInS]4 R=tBu, CMe2Et; [RGaS]4 R=tBu, CMe2Et, CEt3: [SAlR′]4 R═C(SMe3)3, CEtMe2: [SAlNMe3]5: [TeAlR]4 R═Cp*, CEtMe2: [(C(SiMe3)3)GaS]4: [tBuGaS]6: [RGaSe]4 R=tBu, CMe2Et, CEt3, C(SiMe3)3, Cp*, Bu: Cd4In16S33.(H2O)20(C10H28N4)2.5:
IV-VI [S6{SnR}4] R═C(SiMe3)3, Me, Ph; [Se6{SnR}4] R═C6F5, C6H2Me3, p-Tol, C(SiMe3)3
Material consisting of a first element from any group in the transition metals of the periodic table and a second element from any group of the d-block elements include but are not restricted to:—[Cu12Se6(PR3)8] R=Et2Ph, nPr3, Cy3; [Cu18Te6(tBu)6(PPh2Et)7]; [Cu19Te6(tBu)7(PEt3)8]; [Cu27Te15(PiPr2Me)12]; [Ni34Se22(PPh3)10]; [Ag30(TePh)12Te9(PEt3)12]; [Ag30Se8(SetBu)14(PnPr3)8]; [Co4(μ3-Se)4(PPh3)4]; [Co6(μ3-Se)8(PPh3)6]; [W3Se4(dmpe)3Br3]+; Ru4Bi2(CO)12; Fe4P2(CO)12; Fe4N2(CO)12
M Source
For a compound semiconductor nanoparticle consisting of elements (ME)nLm a source for element M is further added to the reaction and can consist of any M-containing species that has the ability to provide the growing particles with a source of M ions. The precursor can consist of but are not restricted to an organometallic compound, an inorganic salt, a coordination compound or the element.
Examples for II-VI, III-V, III-VI or IV-V for the first element include but are not restricted to:—
Organometallic such as but not restricted to a MR2 where M=Mg R=alkyl or aryl group (MgtBu2); MR2 where M=Zn, Cd, Te; R=alkyl or aryl group (Me2Zn, Et2Zn Me2Cd, Et2Cd); MR3 Where M=Ga, In, Al, B; R=alkyl or aryl group [AlR3, GaR3, InR3 (R=Me, Et, iPr)].
Coordination compound such as a carbonate but not restricted to a MCO3 M=Ca, Sr, Ba, [magnesium carbonate hydroxide [(MgCO3)4Mg(OH)2]; M(CO3)2 M=Zn, Cd; MCO3 M=Pb: acetate: M(CH3CO2)2 M=Mg, Ca, Sr, Ba; Zn, Cd, Hg; M(CH3CO2)3 M=B, Al, Ga, In: a β-diketonate or derivative thereof, such as acetylacetonate (2,4-pentanedionate) M[CH3COCH═C(O−)CH3]3 M=Mg, Ca, Sr, Ba, Zn, Cd, Hg; M[CH3COCH═C(O−)CH3]3 M=B, Al, Ga, In. Oxalate SrC2O4, CaC2O4, BaC2O4, SnC2O4. Hydroxide M(OH)2 M=Mg, Ca, Sr, Ba, Zn, Cd, Hg, e.g. Cd(OH)2. Sterate M(C17H35COO)2 M=Mg, Ca, Sr, Ba, Zn, Cd, Hg.
Inorganic salt such as but not restricted to a Oxides SrO, ZnO, CdO, In2O3, Ga2O3, SnO2, PbO2; Nitrates Mg(NO3)2, Ca(NO3)2, Sr(NO3)2, Ba(NO3)2, Cd(NO3)2, Zn(NO3)2, Hg(NO3)2, Al(NO3)3, In(NO3)3, Ga(NO3)3, Sn(NO3)4, Pb(NO3)2 An element Mg, Ca, Sr, Ba, Zn, Cd, Hg, B, Al, Ga, In, Sn, Pb.
E Source
For a compound semiconductor nanoparticle consisting of elements (ME)nLm a source for element E is further added to the reaction and can consist of any E-containing species that has the ability to provide the growing particles with a source of E ions. The precursor can consist of but are not restricted to an organometallic compound, an inorganic salt, a coordination compound or an elemental source. Examples for an II-VI, III-V, III-VI or IV-V semiconductor were the second element include but are not restricted to:—
Organometallic such as but not restricted to a NR3, PR3, AsR3, SbR3 (R=Me, Et, tBu, iBu, Pri, Ph etc.); NHR2, PHR2, AsHR2, SbHR2 (R=Me, Et, tBu, iBu, Pri, Ph etc.); NH2R, PH2R, AsH2R, SbH2R3 (R=Me, Et, tBu, iBu, Pri, Ph etc.); PH3, AsH3; M(NMe)3 M=P, Sh, As; dimethyldrazine (Me2NNH2); ethylazide (Et-NNN); hydrazine (H2NNH2); Me3SiN3.
MR2 (M=S, Se Te; R=Me, Et, tBu, iBu etc.); HMR (M=S, Se Te; R=Me, Et, tBu, iBu, iPr, Ph etc); thiourea S═C(NH2)2; Se═C(NH2)2.
Sn(CH4)4, Sn(C4H9), Sn(CH3)2(OOCH3)2.
Coordination compound such as but not restricted to a carbonate, MCO3 M=P, bismuth subcarbonate (BiO)2CO3; M(CO3)2; acetate M(CH3CO2)2 M=S, Se, Te: M(CH3CO2)2 M=Sn, Pb or M(CH3CO2)4 M=Sn, Pb: a β-diketonate or derivative thereof, such as acetylacetonate (2,4-pentanedionate) [CH3COCH═C(O−)CH3]3M M=Bi; [CH3COCH═C(O−) CH3]2M M=S, Se, Te: [CH3COCH═C(O−)CH3]2M M=Sn, Pb: thiourea, selenourea (H2NC(═Se)NH2.
Inorganic salt such as but not restricted to Oxides P2O3, AS2O3, Sb2O3, Sb2O4, Sb2O5, Bi2O3, SO2, SeO2, TeO2, Sn2O, PbO, PbO2; Nitrates Bi(NO3)3, Sn(NO3)4, Pb(NO3)2.
An element:—Sn, Ge, N, P, As, Sb, Bi, S, Se, Te, Sn, Pb.

This patent is subject to a terminal disclaimer.