Disclosed are fluorocarbon emulsions comprising amino acids and substances related to amino acids, such as substituted amino acids or amphoteric groups of amino acid side chains, for example, the imidazolyl group of histidine. Emulsion formulations comprising imidazole and imidazole based drugs possess anti-inflammatory and antipyretic properties which counteract transient inflammatory responses which occur when these emulsions are administered in vivo. Lipid constituents of histidine-containing emulsions are protected against oxidation caused by free radical formation.. Disclosed also are emulsion formulations buffered with amino acids comprising histidine, imidazole, and related compounds that have a buffering capacity sufficient to maintain the emulsion pH within a specified range under storage conditions and protect these emulsions from the endogenous production of acid. Disclosed also is a method of calculation which assists in the selection of an optimum buffer composition and concentration to preserve physiological compatibility and stability of the emulsions within selected pH limits.

Imidazole and imidazoyl containing compounds have properties that make them useful in pharmaceutical formulations; for example, imidazole is among the agents which exert a therapeutic effect in alleviating inflammation and tissue injury arising from physiological stress and mediated by prostaglandin end products.
Physiological stress results in an inflammatory response, accompanied by increased prostaglandin synthesis. Phagocytosis of inert particles, bacteria and viruses induces the release of inflammatory hormones and prostaglandins. The stress provoked by reduced oxygen tension, interrupted blood flow, or infections, is often accompanied by increased synthesis of prostaglandins, including the thromboxanes, from arachidonic acid. This synthesis, which occurs primarily in macrophages, begins with the conversion of free arachidonic acid to an alicyclic endoperoxide prostaglandin intermediate, PGH.sub.2, by means of a cyclo-oxygenase enzyme. PGH.sub.2 is the precursor for several end product prostanoids. Among these are prostacyclin, PGI.sub.2, whose formation is catalyzed by prostacyclin synthetase; the active prostaglandins PGF.sub.2a, PGE.sub.2, and PGD; and the thromboxane, TxA.sub.2, whose formation is catalyzed by thromboxane synthetase. Imidazole inhibits thromboxane synthetase and prevents the synthesis of TxA.sub.2 ; other agents, such as aspirin-like compounds, ibuprofen and indomethacin, inhibit cyclo-oxygenase, thus preventing the synthesis of all the prostanoids.
The prostaglandin end products have several various effects. They can act themselves to alter the pain threshold and, in a manner similar to mediators of the allergic response, to increase capillary permeability. They can also act on cells, primarily macrophages and platelets, to release substances that mediate an inflammatory response, which can involve infiltration of tissues with neutrophils, deposition of immune complexes, edema, and pain.
PGI.sub.2 and TxA.sub.2 are the most biologically active of the prostanoids, but exert opposite vasoactive and hemodynamic effects. For example, PGI.sub.2 is a potent vasodilator and inhibitor of platelet aggregation, whereas TxA.sub.2 is a vasoconstrictor and powerful inducer of platelet aggregation. Platelet aggregation results in an inflammatory response, thrombosis, and the unfavorable consequences. In the kidney, for example, thrombosis is followed by glomerulosclerosis, hypertension and cardiac hypertrophy. Imidazole, by selectively inhibiting thromboxane synthetase, shunts the conversion of PGH.sub.2 from TxA.sub.2 to PGI.sub.2, produces physiologically beneficial effects, and reduces tissue damage.
The effect is well demonstrated in the kidney, in which the tissue injury associated with inflammation consists of destruction of the glomerular capsule resulting from vasodilation, followed by deposition of fibrous material. Zipser, R. et al., Circulation Research 47(2): 231-237 (1980), found exaggerated prostaglandin and thromboxane production in the ex vivo perfused kidney, under conditions of renal vein constriction, which could be inhibited by preincubation with imidazole. Saito, H. et al., Nephron 36:38-45 (1984), studied the inhibition of inflammatory damage in the kidney by a specific thromboxane A2 synthetase inhibitor, 1-benzylimidazole (BIm). This agent delayed the progression of glomerulonephritis and in the tissues of treated animals platelet aggregation and fibrin deposits were reduced. Okegawa, T. et al. J. of Pharmacology and Experimental Therapeutics 225(1):213-218 (1983) noted that in endotoxic shock, toxin-stimulated macrophages infiltrate into tissues where they synthesize arachidonate metabolites which modulate an inflammatory response comprising vasodilation, edema and pain. A comparative study of the effectiveness of inflammation suppression by imidazole, indomethacin, and ibuprofen by Schirmer, W et al. Current Surgery March-April, 1987, pp. 102-105) in a model system of acute peritoneal sepsis indicated that imidazole, which inhibits only the formation of thromboxane A2, maintained its activity in preventing endotoxic shock over a longer period of time than the other two agents which act to inhibit the formation of all prostaglandins.
Histidine appears to have a protective effect on fatty acids, which are often present in the emulsifying agents of pharmaceutical preparations. Many medically useful agents are used parenterally in the form of emulsions, comprising a hydrophobic phase dispersed in an aqueous system. The emulsifying agent is commonly a phospholipid, which, because of its amphipathic nature, is able to form a stable association with both phases. Phospholipids are composed of a glycerol group to which fatty acids are attached by ester bonds. Emulsions may, in addition, comprise other types of lipids, some of which also contain fatty acids.
Parenteral emulsions present a particularly difficult buffering problem when they have an emulsifying agent such as phospholipids which comprises fatty acids. Phospholipids and other molecules comprising fatty acids may generate acidic substances after incorporation into emulsions, either while in storage or in use. The acidic substances may be free fatty acids and lysophosphatide species produced either from the hydrolysis of the ester bonds between the glycerol and fatty acid components of phospholipids, or similar free fatty acids resulting from the oxidation of unsaturated fatty acids at the site of their double bonds. Histidine, together with its structurally related amino acid, tryptophan, and sulfur-containing methionine, appears to be responsible for the ability of some proteins to quench singlet oxygen produced by photosynthetic processes and by this means to prevent their own oxidative decomposition. The rate of physical quenching is the same for both free amino acids and those incorporated into a protein structure. (Matheson, R. et al., Photochemistry and Photobiology, 21:165-171 (1975)). It is quite probable that histidine would be similarly effective in preventing the oxidative degradation of phospholipid fatty acids (or free fatty acids) which leads to acid generation and a decrease in pH in fluorocarbon emulsions.
With the exception of the stomach, the pH range in the body is maintained, through chemical exchanges occurring principally in the renal and respiratory systems, at about 6.4 to 7.5 for the tissues and between 7.35 and 7.45 for the extracellular fluids. Most physiological processes and biochemical reactions occur then within relatively narrow pH limits. Little is known about the rates of enzyme reactions at physiological pH. The physiological pH restriction may provide an optimum pH range for the rates of certain enzyme reactions, and may act as a control mechanism for those for which that pH is not optimum.
It is clear, however, that processes in some tissues and organs are sensitive to small changes in pH. The effect of an acid environment on the heart is an example. As the pH of arterial blood falls, the coronary vessels dilate to increase blood flow and a supply of oxygen to the cardiac muscle; at a critically low pH, there is a sudden, sharp decrease in myocardial contractility. In dogs, the lethal pH is 6.0, at which point there is cardiac arrest in extreme diastole. The effect is independent of the nature of the anion species of the acid. Another example is an effect such as occurs in metabolic alkalosis, wherein an increase in the pH of the blood moves extracellular fluid into the cells, resulting in tissue edema.
It is important then that substances introduced parenterally into the body, and particularly those placed in the circulation, most critically the cardiac circulation, are buffered to a physiological pH, so as not to disturb the biochemical balance. It is further important that the agents used to buffer these substances are physiologically innocuous.
The natural physiological buffering agents are principally carbonate and phosphate ions and the amino acids. In the blood the buffers NaHCO.sub.3 /H.sub.2 CO.sub.3 along with constituent blood proteins hemoglobin, oxyhemoglobin, albumin and globulin and Na.sub.2 HPO.sub.4 /NaH.sub.2 PO.sub.4 resist changes in pH. Proteins may contain groups which act as buffers, depending on the pH; these are commonly the carboxyl groups of glutamic and aspartic acids and the amino groups of lysine, the guanido group of arginine and the imidazolyl group of histidine.
Because of their natural buffering capacity, carbonates and phosphate salts are commonly used as buffers in intravenous solutions. A difficulty with these buffers that becomes more significant in highly buffered solutions, is that both carbonate and phosphate ions form insoluble precipitates with divalent cations such as magnesium and calcium. This has two undesirable effects. First, it reduces cation concentrations and inhibits critical metabolic processes, such as Mg.sup.++ dependent enzyme reactions, and Ca.sup.++ dependent muscular contractions. Secondly, the insoluble precipitates formed can block the blood flow through small vessels, and those formed when solutions are introduced into cavities such as the brain ventricles can deposit a film on internal membrane surfaces which will then interfere with membrane transport.
Amino acids may be advantageously used as buffers in pharmaceutical applications because they have neither of these undesirable actions, and they are, in addition, metabolizable, nutritive substances.
Histidine appears to act as a natural buffer in tissue such as muscle where high metabolic activity occurs. The process of anaerobic glycolysis necessary for rapid ATP production in exerted muscle is associated with elevated lactate, proton accumulation and a fall in pH. Abe, H. et al., Am. J. Physiol. 249:R449-R454 (1985), found that histidine and histidine-containing dipeptides are the principal buffers in the skeletal muscle of fish such as marlin that has a high activity pattern, and that the histidine buffered tissue had a higher buffering capacity than corresponding tissue from less active fish. In a parallel study on humans, Parkhouse, W. S. et al., J. Appl. Physiol. 58(1):14-17 (1985). found higher buffering capacity and higher levels of histidine related peptides in needle biopsies of muscle tissue from athletes capable of superior high-intensity running performance.
Histidine has been used as a buffer for cardioplegic solutions which are used to preserve organs such as hearts and kidneys during surgical procedures in which ischemic intervals occur and during transplant procedures. Bretschneider U.S. Pat. No. 4,415,556. The composition of these solutions has been determined empirically to comprise substances normally found in blood and electrolytes favorable to preserving the contractility of cardiac muscle and preventing edema. Histidine content is adjusted so that the solutions provide the pH and pH buffering capacity of cardiac tissue as determined by comparative manual titrations. (Kresh, J. Y. et al., J. of Thoracic and Cardiovascular Surgery, 93(2):309-311 (1987)).
One problem in buffering lipid containing emulsions is that acid generating oxidative processes, which occur to an unpredictable extent, may exceed the buffering capacity of the solution, and bring the pH down to unacceptably low levels.
One approach to this problem has been to prepare an emulsion and add sufficient sodium hydroxide or other inorganic base to the preparation to achieve an initial pH high enough to anticipate a degree of acid generation. However, this method of protection, high formulation pH, can actually accelerate the degradation of the lipids and aggravate the problem it is intended to correct.
Presuming one could predict the amount of expected proton generation in a lipid-containing emulsion, it would still not be possible to provide the necessary buffering capacity to the emulsion accurately enough so as to assure its pH stability within an acceptable range using present methods.
The major difficulty is that there is no theoretical mathematical expression for the titration curve of a polyprotic acid or base, and hence no way to calculate the buffer capacity of these substances exactly. The present method of calculating buffer capacity depends on the use of the Henderson-Hasselbach equation. This expression, ##EQU1## relates the pH to the ionization constant for a single ionizable group of a weak acid or base. Buffer capacity can be determined for that ionizable group by calculating the change in the log Ac.sup.- /HAc term corresponding to a change in the pH. One of the shortcomings of this method is that it can only provide an approximation of the buffering capacity of a polyprotic buffer or a mixture of buffers having different pK.sub.a 's, because the buffering capacity of each ionizable group must be calculated independently, and the interaction between these groups ignored. When the pK.sub.a 's are quite different, the error is negligible (but not zero); but when they are close in value, the mis-estimation is serious.
The pK is that pH at which a weak acid or base is 50% converted to its salt, and it is at this point that its buffering capacity, the amount of H.sup.+ or OH.sup.- ions it can neutralize per unit change in pH, is highest. Histidine is one of the most effective amino acid buffers for parenteral use because it contains an imidazole ring having a nitrogen site with a pK of about 6.83, near the center of the physiological pH range. Imidazole itself, in which the pK at the nitrogen site is about 6.99, also acts as a buffer.
A determination of the optimal agent for providing the required buffer capacity by the trial and error process of manual titration would be tedious and expensive and particularly difficult if a combination of amino acids were used.
Further, an exact determination of the necessary buffering capacity in the emulsion must take into consideration the influence of the ionizable groups of the phospholipid species present. Although the effect of these groups is negligible at neutrality, having pK.sub.a 's of 1-2 and 10-13 for most species, the effect is also not zero. These effects cannot be determined manually, because the titration of the buffer with acid or base would hydrolyze the lipid components, generating interfering acid or base.
The emulsions cannot be adequately buffered simply by adding an excess of an amino acid buffer, because the constraint that all administered parenteral agents must be isotonic limits the amount of amino acid that can be added to the emulsion. For that reason it is important to determine precisely the effective amount of these agents in the emulsions.
Amino acids such as histidine and other structures containing an imidazolyl group appear to be particularly appropriate buffering agents for fluorocarbon emulsions. Moreover, the anti-inflammatory properties of imidazole and the anti-oxidative properties of histidine can provide further advantages when incorporated in fluorocarbon formulations.
Fluorocarbon emulsions can be widely used intravascularly and extravascularly as contrast agents. Further, fluorocarbons have the capacity to dissolve high concentrations of oxygen, making them suitable as artificial blood and as oxygen transport agents in the treatment of local ischemias. However, the intravascular administration of fluorocarbon emulsions is frequently accompanied by a transient fever and inflammatory response. I have found that agents such as imidazole, ibuprofen and indomethacin have an anti-pyretic effect which mitigates the inflammatory response when they are present in these emulsions.
For all the foregoing reasons, amino acids such as histidine and its constituent imidazolyl group are believed to be particularly effective pharmacological components as well as appropriate buffering agents for fluorocarbon emulsions.
It is therefore an object of the invention to provide formulations for fluorocarbon emulsions comprising an effective therapeutic concentration of imidazole or related pharmacologically active agents.
It is desirable to provide formulations for fluorocarbon emulsions which are protected against decomposition by the use of effective buffers and antioxidants. It is therefore further an object of the invention to provide formulations for fluorocarbon emulsions comprising effective buffering concentration of amino acids, and particularly histidine and related compounds comprising an imidazolyl group.
It is further an object of the invention to provide a method for selecting buffers for formulations of fluorocarbon emulsions, comprising amino acids which provide a known buffering capacity for those emulsions within a given pH range.
It is further an object of the invention to provide formulations of amino acid buffered fluorocarbon emulsions which are stable within a physiological pH range during a sterilization process and for an estimated period of storage.

Fluorocarbon emulsions containing amino acid based anti-inflamatory agents and buffer systems


There are provided a process for fabricating MEMS device that includes a plurality of through-holes capable being arranged at a high density, the through-holes having a tapered end portion. Through-holes having vertical side surfaces and tapered bottoms are provided by a processing method including the steps of: disposing quadrilateral patterning having desired dimensions on a silicon substrate having a flat surface of a crystal plane, etching the substrate to a desired depth by dry etching that can realize a high aspect ratio etching, and anisotropic wet etching the dry etched substrate with a KOH aqueous solution containing isopropyl alcohol mixed thereinto.

In recent years, MEMS devices, which can advantageously form microstructures having a higher aspect ratio (processing depth/opening width ratio) as compared with semiconductor devices, have become extensively applied to physical sensors such as pressure sensors and acceleration sensors, mechanisms such as micromirrors and microactuators to which electrostatic force or piezoelectric systems have been applied, and fluid devices such as nozzles for ink jetting.
In the processing and manufacture of these microstructures, semiconductor materials such as silicon are mainly applied. Processing methods include, for example, an anisotropic wet etching method in which a structure is formed by taking advantage of a difference in etching rate of silicon crystal planes, and a dry etching method to which an RIE (reactive ion etching) apparatus of an ICP (induction coupled plasma) system that can realize processing of high-aspect ratio grooves is applied. Processing of MEMS devices can realize the formation of three-dimensional structures and movable structures of silicon, is superior in processing accuracy to machining, and, thus, can be applied to various structures.
Processing by a combination of dry etching with anisotropic wet etching is described in NPL 1. In this literature, in order to remove scallops formed on the side surface of holes formed by dry etching to smooth the side surface, etching is carried out by applying a KOH aqueous solution containing isopropyl alcohol (IPA) mixed thereinto to improve surface roughness on the side surface of holes. Structures to which this method has been applied are applied to dies of molds formed of silicon structures.
In MEMS fluid devices, the arrangement of a plurality of silicon nozzles is advantageous for stirring or mixing of liquids. In order to form microstructures such as silicon nozzle structures, preferably, the end portion of through-holes has a small-hole shape. In conventional structures, a method is generally adopted in which patterning in a nozzle form is carried out on a plane for planar partial etching to form a groove and the structure is planarly applied. In recent years, however, three-dimensional structures are required as nozzles for ink jet printers. PTL 1 proposes a method for simultaneous production of through-holes. PTL 1 describes a method in which, in a dry etching method that can form vertical holes, a multi-layer mask is applied to form openings in a vertical hole form continuously at an end portion of tapered openings, thereby producing a structure including simultaneously produced through-holes. More specifically, in this structure, an inclined plane is formed from the openings, and the end portion of the holes is vertical.
Further, in the MEMS sensors and actuators, individual or a plurality of wirings are extracted from a device substrate so as to provide movable or sensing functions as various sensors and actuators. These MEMS structures are divided into device substrates in which movable portions or sensing portions have mainly been processed, and electrode substrates that function to exchange electric signals. In some cases, these structures further include cap substrates such as lids.
A method in which a wiring is extracted horizontally (transverse direction) from the device substrate, and a method in which a wiring is extracted vertically (longitudinal direction) from the device substrate are considered as a method for extracting a wiring in the MEMS structure. PTL 2 describes a method in which the wiring is extracted vertically, and a through-hole wiring structure is formed at a position away from the structure prepared in the device substrate.


A mounting system has a mounting device with a carrier component and a mechatronic installation component, a displacement component arranged above the mounting device in an elevator shaft and a support member connected between the carrier component and the displacement component. The displacement component displaces the mounting device in the shaft using the support member, wherein the carrier component is supported by an upper support roller on a support wall of the shaft during the displacement in the shaft. The support member generates a diagonal pull perpendicular to the support wall surface. The mounting system also has a compensating element that counteracts a tilting of the carrier component about the upper supporting roller perpendicular to the support wall during the displacement in the shaft.

WO 2017/016783 A1 describes a mounting system for carrying out an installation operation in an elevator shaft of an elevator system. The mounting system has: a mounting device comprising a carrier component and a mechatronic installation component in the form of an industrial robot; a displacement component arranged above the mounting device in the elevator shaft; and a support means, designed for example as a rope or chain, which is at least indirectly fixed to the carrier component. The displacement component can displace the carrier component and thus the mounting device in the elevator shaft by means of the support means, it being possible for the carrier component to be supported by means of an upper support roller on a support wall of the elevator shaft at least during a displacement in the elevator shaft. In the mounting system described in WO 2017/016783 A1, it is not ensured that the carrier component is in fact always supported by means of the upper support roller on the support wall during a displacement in the elevator shaft. This can thus lead to the mounting device swinging and, in extreme cases, striking the elevator shaft during a displacement.
WO 2015/102525 A1 describes a device for lining a mine shaft with concrete, which device can be lowered into the mine shaft while being retained by a support means. The mine shaft is mainly vertical, but has portions which are inclined with respect to the vertical. The device has variable support elements by means of which it can be supported against shaft walls of the mine shaft. The support is such that the support means always extends vertically.

This patent is subject to a terminal disclaimer.

Mounting system for performing an installation operation in an elevator shaft of an elevator system


The present invention pertains to a device for deploying and retrieving a flexible tissue containment sac within a body cavity, through a minimal access incision. The device generally includes a tubular introducer having a flexible tissue containment sac disposable in a compressed configuration within the lumen of such tubular introducer. An elongate plunger shaft or pushing member is insertable or passable through at least a portion of the introducer lumen to push the containment sac out of the distal end of the lumen. Attached to the containment sac and extending through the lumen of the introducer is a tether. A portion of the tether may extend out of the proximal end of the introducer. The proximal end of the tether may be grasped and pulled in a proximal direction to pull the containment sac to a retrieved position on the end of an extractable shaft or, in embodiments absent such extractable shaft, to pull at least a portion of the containment sac into the introducer lumen.

The advent of modern endoscopic surgical procedures (e.g. laparoscopic procedures) has enabled the performance of complex excisional surgery through minimal access incisions of approximately 1 centimeter or less. Such excisional procedures may be utilized to excise or resect relatively large volumes of tissue, tumors, organs and the like. The extraction and removal of such excised tissues, tumors, organism or the like is, however, sometimes problematic because such excised tissue, tumors, organs or the like are often too large or too bulky to be removed directly through the minimal access (e.g. 1 cm) endoscopic incision. Also, the excision, manipulation and removal of certain non-benign matter (e.g. infected tissue, fecally contaminated segments of bowel, cancerous tumors) is complicated by the need to contain such non-benign matter in a manner that will prevent or deter dissemination or spread of such non-benign matter within the body cavity.
Accordingly, there exists a need in the art for new appliances and apparatus for containing, manipulating, liquidizing or debulking, and/or removing excised tissues, tumors, organs or other matter, through relatively small minimal access incisions.
A surgical tissue bag and method for percutaneously debulking tissue is purportedly described in U. S. Pat. No. 5,037,379 (Clayman et al.).
A surgical tissue sac for use in endoscopic surgical procedures is presently available commercially under the name ENDOPOUCH.TM. (Ethicon, Inc., Division of Johnson & Johnson, Route 22, P. O. Box 151, Somerville, New Jersey 08876).
The surgical tissue containment sacs of the prior art may present certain shortcomings in that such prior devices (a) do not adequately open or fully expand when inserted into a body cavity through a minimal access incision, (b) lack means for maintaining directional orientation of the bag opening during intracorporeal usage, (c) lack sufficient transparency to permit ease of viewing through the wall of the containment sac and/or (d) lack means for facilitating passage of instruments into the containment sac for purposes of treating, grinding, debulking or removing material from the interior of the sac.

Method and system for enclosing, manipulating, debulking and removing tissue through minimal access incisions


The present invention relates to a hydraulic tool including a working unit, a driving unit, a connection unit, and a switching device. The working unit is adapted to operate a workpiece. The driving unit is configured to drive the working unit and comprises a housing and a movable part provided in the housing and movable between an initial position and an end position. The connection unit connects the working unit and the driving unit. The switching device can rotate between a first position and a second position. When the switching device is in the first position, the movable part of the driving unit has a first stroke from the initial position to the end position; when the switching device is in the second position, the movable part of the driving unit has a second stroke smaller than the first stroke.

The contents of this section merely provide background information related to the present disclosure and may not constitute the prior art.
In general, a hydraulic tool (also referred to as a crimping tool in some cases) for crimping a workpiece such as a tube includes a working unit (also referred to as a crimping unit in some cases), a driving unit for driving the working unit to process the workpiece, and a connection unit for connecting the working unit to the driving unit. The driving unit is typically a hydraulic driving unit that includes a hydraulic cylinder, a piston and a piston rod accommodated in the hydraulic cylinder. The piston and the piston rod are herein collectively referred to as a movable part. After the hydraulic tool is assembled, the movable part of the driving unit typically has a single stroke.
Therefore, there is a need in the art for a hydraulic tool with changeable stroke and/or replaceable working unit.


The wavelength router comprises two flat waveguides, and these flat waveguides are connected by connecting waveguides. In each flat waveguide, optical path converters are created at connecting sections with the connecting waveguides. The optical path converters convert the light propagation direction in the flat waveguide to the light propagation direction in the connecting waveguides, or perform inverted conversion of this conversion. By this configuration, a compact element with a high wavelength resolution can be implemented.

1. Field of the Invention
The present invention relates to a wavelength router for setting a route of a wavelength-multiplexed light signal for each wavelength.
2. Description of Related Art
Of wavelength routers, various types have been known, including an array waveguide diffraction grating element, and an element using grating.
In document 1, xe2x80x9cOptronics (2000), No. 2, pp. 139-143xe2x80x9d, an example of an array waveguide diffraction grating element is mentioned. Array waveguide diffraction grating elements have been the subject of vigorous research, since a plurality of input ports can be set and a single level operation is possible.
The array waveguide diffraction grating element has a configuration where two star coupler-shaped flat waveguides are connected with channel waveguides (connecting waveguides), which lengths are different from each other. The input/output ports are connected to ports on the side of the flat waveguide opposite to the connecting waveguides.
The wavelength dispersion characteristic is an index to measure the performance of an element. This indicates how much the direction of the optical beam changes with respect to the change of wavelength. The deflection direction of a beam is determined by the relationship of the optical path length difference between adjacent connecting waveguides and the width between the guides. As the optical path length difference increases and as the width d between the waveguides decreases, the deflection angle d "THgr"r increases. The dispersion is given by the following formula (a).
xcexd"THgr"r/dxcex=xe2x88x92xcex94L/d . . . (a)
Here xcex94L is an optical path length difference between the adjacent connecting waveguides. In the case of array waveguide diffraction grating, the cross-talk characteristic aggravates if optical coupling is generated between the connecting waveguides, so a 20 xcexcm or more of space d is required between the connecting waveguides. Formula (b) shows the relationship of xcex94L with the filter transmission area width xcex94F.
xcex94L=2xcex2/(Nxcex94xcexF)xe2x80x83xe2x80x83(b)
Here N is the number of connecting waveguides. Therefore the following formula (c) is established.
d"THgr"r/dxcex=xe2x88x922xcex/(Ndxcex94xcexF)xe2x80x83xe2x80x83(c)
To have a good cross-talk characteristic, N must be 100 or more, so dispersion cannot be increased very much. But according to formula (c), dispersion can be increased by decreasing d.
For reference, the length L of the star coupler is calculated by the following formula (d).
L=(xcex94xcexF/xcex94xcexC)(NDd)/(2xcex)xe2x80x83xe2x80x83(d)
Here D is a space of the output ports and xcex94xcexc is a wavelength difference between the wavelength channels. As the width d of the waveguides increases, the length L of the star coupler increases. For example, if xcex94xcexF/xcex94xcexc=1, d/xcex=20, D=30 xcexcm and N=100, then L=30 mm.
With the foregoing in view, it is an object of the present invention to provide a compact element with a high wavelength resolution by increasing dispersion by minimizing the space d between the connecting waveguides.
A wavelength router, according to the present invention, comprises two first waveguides, which have a plurality of input/output sections and a plurality of connecting sections, having a structure such that light entering from each of the input/output sections diffuses toward each of the connecting sections, a plurality of second waveguides, and optical path converters which guide light from the first waveguides to the second waveguide, or guide light from the second waveguides to the first waveguides, wherein each of the connecting sections of the two first waveguides are inter-connected via the plurality of second waveguides, and the distances from the plurality of light input/output sections to each of the connecting sections are different from each other, and the optical path converters are disposed at the connecting sections.
According to this configuration, disposing the optical path converters decreases the width between the second waveguides compared with a conventional configuration. As a result, the wavelength dispersion characteristic improves. Therefore the length of the first waveguides can be decreased.


An arbor for a hole saw includes a shaft and a plurality of pins having either bearing surfaces, drive portions or both for engaging the hole saw. The arbor further includes a fixed position flange and a locking plate located above the flange, to which the pins are connected. The saw is mounted to the arbor and has a cylindrical body portion having a closed end defined by a drive plate and an opposite end defining a cutting edge for performing sawing operations on a work piece. The drive plate includes apertures for receiving the drive portions of the pins which pass through holes in the flange. When assembled the drive ends of the pins extend through the holes in the flange and into the mating drive plate apertures such that the bearing surfaces on the pins engage and support the drive plate of the hole saw. The assembly is held together by a locking nut positioned above the locking plate and threaded onto the shaft such that it can be brought into engagement with the locking plate thereby urging and maintaining the bearing surfaces of the pins in engagement with the drive plate.

Hole saws are typically used to cut large diameter holes in materials such as wood and metal and are usually mounted by means of an arbor to a drill press or other power tool. During a cutting operation, these saws generate high levels of vibration and are prone to rocking back and forth on the arbor, an effect known to those skilled in the art as wobble. This effect causes premature wear in the saw and diminishes its cutting accuracy and efficiency.
To counter these effects, prior art arbors incorporate a fixed position flange and drive pin arrangement. The hole saw characteristically includes a cylindrical body portion defining a cutting edge at one end. The opposite end of the body portion is closed by a drive plate. A threaded bore at the center of the drive plate mates with a lower threaded shaft portion on the arbor. The saw is threaded onto the arbor until it abuts the aforementioned fixed position flange. The drive pins pass through holes in the flange and engage mating holes in the drive plate. The flange and the drive pins coact to support the hole saw during a sawing operation. However, it is often difficult or impossible to both align the drive pins with the holes in the drive plate and have the drive plate abut the fixed position flange. Generally, the saw must be backed off from the flange until the holes in both the saw and flange are aligned. This causes a gap to be created between the saw and the flange thereby preventing the drive plate from being supported by the fixed position flange. The presence of the gap allows the saw to wobble during a sawing operation. This problem is exacerbated as the saw and its mounting threads wear.
Based on the foregoing, it is the general object of the present invention to provide an arbor for supporting a saw that attenuates vibration and wobble while obviating the previously described alignment problems.


The present invention discloses a Lithium ion battery and an electrolyte thereof, the electrolyte comprising an organic solvent, a lithium salt and an additive. The additive comprises a cyclic fluoro carbonate (A), a cyclic phosphazene (B), a cyclic sulfate and a lithium fluoro oxalate borate (D). The lithium fluoro oxalate borate (D) has following formula:

Lithium-ion secondary batteries are widely used in electric vehicles and consumer electronics because of their high energy density, high output power, long cycle life and low environmental pollution. Electrolyte as an ion transport "highway" plays a very important role in the lithium-ion battery.
With the increased energy density requirement of Lithium ion batteries, a new generation of Lithium ion battery with a positive electrode of Ni, Co and Mn and a negative electrode of high energy density graphite and Si has become current research hotspot. However, because volume expansion of Si is much larger than volume expansion of the traditional graphite, expansion and contraction of SiC negative electrode during cycle will cause SEI film to break, thereby resulting in the film-forming additive or solvent to be consumed continuously and even to be exhausted and eventually leading to battery diving.
In the prior art, the usual way is to add a large amount of film-forming additives so that the film is regenerated after each cycle. This way allows the battery to be maintained for a period of time without diving. However, in the redox process for the film formation, a large amount of acid gas is generated and the resulting acid gas corrodes the positive and negative passivation films, or even destroy the positive active material which bring about a serious threat to the battery safety.
Moreover, a large amount of added film-forming additives inevitably lead to increased interface impedance, resulting in decrease in the rate capability of the Lithium ion battery. One of the difficulties of the current study is how to improve the cycle life and storage life of lithium-ion battery at the same time without reducing the rate capability of lithium-ion battery.
In view of this, it is necessary to provide a Lithium ion battery and its electrolyte with excellent performance which Lithium ion battery exhibits reduced low temperature internal resistance and improved cycle life, high temperature storage performance and safety performance.

Abstract: Compared with the prior art, the electrolyte of the present invention may form a stable CEI and SEI film on the surface of positive and negative electrodes, protect the interface between positive and negative electrodes, improve the acidic atmosphere of Lithium ion battery electrolyte, and reduce the damage effect of HF on the interface between positive and negative electrodes, while reducing low temperature resistance of lithium-ion battery, improving cycle life, high temperature storage performance, safety performance and rate capability of lithium-ion battery.

Contemporary Amperex Technology Co., Limited


A method for synthesizing sulfurized oligonucleotide analogs, such as phosphorothioate and phosphorodithioate analogs, is provided that employs a thiophosphorus compound, such as a thiophosphoric, dithiophosphoric, thiophosphinic, or dithiophosphinic acid disulfide or polysulfide, as a sulfurizing agent. The method of the invention may be used to sulfurize any phosphorous(III)containing intermediate. Preferably, the method is practiced on a commercial DNA synthesizer using phosophoramidite and/or phosphorthioamidite intermediates.

With the development of efficient methods of synthesis, interest has arisen in the use of anti-sense oligonucleotides to treat a variety of diseases, particularly viral infections, e.g. Matsukura et al, Proc. Natl. Acad. Sci., Vol. 86, pgs. 4244-4448 (1989). An antisense oligonucleotide is a synthetic oligonucleotide of varying length, usually in the range of about 12 to 30 nucleotides, or nucleotide analogs, whose sequence is complementary to a predetermined segment of the RNA, either freshly transcribed or the messenger (mRNA), critical to some viral function. It is believed that when an antisense oligonucleotide hybridizes to its target RNA, it either blocks translation or processing of the RNA or makes it susceptible to enzymatic degradation.
One problem with this approach has been the difficulty of getting the antisense oligonucleotide to its target RNA in sufficient concentration and for sufficient duration to be effective in shutting down the synthesis of undesired proteins, e.g. viral enzymes, coat proteins, and the like. The susceptibility of the phosphodiester linkage of the oligonucleotides to nuclease digestion is believed to be an important cause of this difficulty, and has prompted the development of a variety of nucleoside oligomers linked by nuclease-resistant analogs of the natural phosphodiester bond, e.g. Miller et al, U.S. Pat. No. 4,511,713 and Ts'o U.S. Pat. No. 4,469,863 (methyl- and arylphosphonates); Miro et al, Nucleic Acids Research, Vol. 17, pgs. 8207-8219 (1989) (phosphoroselenoates); Brill et al, J. Am. Chem. Soc., Vol. 111, pg. 2321 (1989) (phosphorodithioates); and Matsukura et al, Proc. Natl. Acad. Sci., Vol. 84, pgs. 7706-7710 (1987), and Gene, Vol. 72, pgs. 343-347 (1988) (phosphorothioates).
The phosphorothioate and phosphorodithioate analogs are especially promising because they are highly nucleaseresistant, have the same charge as natural oligonucleotides, and are taken up by cells in effective amounts.
Phosphorothioates are conveniently synthesized by automated DNA synthesizers using hydrogen phosphonate chemistry, which permits the phosphonate backbone to be sulfurized in a single step off of the automated synthesizer after synthesis. This is advantageous because the phosphonate moieties are sulfurized by exposure to elemental sulfur dissolved in an organic solvent. Since the sulfur readily precipitates out of solution, the offcolumn sulfurization avoids costly blockages of valves and tubing of the synthesizer by sulfur precipitates. A drawback of of this route of phosphorothioate synthesis is that coupling yields during chain elongation are typically lower than those obtained using phosphoramidite chemistry, Gaffney and Jones, Tett. Lett., Vol. 29, pgs. 2619-2622 (1988). The practical importance of high coupling yields is demonstrated by the synthesis of a 28-mer where a 99% coupling yield per step results in an overall yield of 76% (0.99.sup.27), whereas a 96% yield per step results in an overall yield of only 33% (0.96.sup.27).
Phosphoramidite chemistry, with coupling yields typically greater than 99%, would be a highly desirable approach to phosphorothioate and phosphorodithioate synthesis. However, the phosphite intermediates, which would be sulfurized, are unstable under the conditions of the detritylation step of the reaction cycle. This requires that the phosphite linkage be sulfurized after each coupling step. For practical purposes, such sulfurizations would have to be carried out on an automated synthesizer, but the sulfur precipitation problem discussed above precludes the use of any of the commercially available machines. Moreover, the sulfurization rate of the phosphites is relatively slow and suffers from side reactions that lead to increased contamination of the final product.
In view of the desire to employ phosphorothioate and phosphorodithioate analogs of oligonucleotides as pharmaceutical compounds, it would be advantageous to have available a method for sulfurizing that achieved the highest possible yields of completely sulfurized analogs and that was amenable for use with automated synthesizers, particularly with phosphoramidite and/or phosphorthioamidite chemistries.

Method of synthesizing sulfurized oligonucleotide analogs


A data labeling method, apparatus and system are provided. The method includes: sampling a data source according to an evaluation task for the data source to obtain sampled data; generating a labeling task from the sampled data; sending the labeling task to a labeling device; and receiving a labeled result of the labeling task from the labeling device. As such, an automatic evaluation of data can be implemented by using the evaluation task, and evaluation efficiency is improved.

At present, in the methods for measuring data capability and data quality of a Knowledge Graph (KG), it is mainly used a series of data evaluation indexes to reflect such data capability and data quality. Subject-Predicate-Object (SPO) attribute accuracy rate is taken as an example. The accuracy of a piece of data can be determined by evaluating the SPO in the data. For example, if S in a piece of data is "Yandang Mountain", P is "totally covers", and O is "450 km2", then the SPO for this data is accurate. As another example, if S in a piece of data is "A certain company", P is "is established on", and O is "a certain day, a certain month, and a certain year", then the SPO for this data is inaccurate because the date is incorrect.
At present, indexes used to evaluate knowledge graph data include accuracy rate, repetition rate, low quality rate and the like. As the knowledge graph that is constructed with data becomes more and more complex, a more accurate evaluation of data indexes is needed. However, there are currently many problems with the standard iterative stability and the analysis of the data results of the overall data indexes. For example, processes are decentralized and management costs are high; manual evaluation standards are inconsistent; efficiency of manual evaluation is low; data is processed repetitively and overall time-consuming is long.

Data labeling method, apparatus and system

BEIJING BAIDU NETCOM SCIENCE AND TECHNOLOGY CO., LTD.


When a non-circular workpiece is to be machined by an NC cylindrical grinding machine, the latter is controlled such that the velocity of each of the main spindle and grinding head does not exceed a threshold allowable by the machine. A non-circle data pre-processing section is provided to convert a group of angle and lift points relating to the shape data into profile data to determine the complete circumferential length of the profile. The circumferential length of the profile is divided into line segments of minute and equal length at a plurality of division points. When the tool is brought into contact with the workpiece at each of the division points, a reference X/C axes data relating to the X-axis position of the tool and the rotational angle of the main spindle at this time is prepared. The reference X/C axes data are selected out to prepare temporary X/C axes data which in turn are used to determine the velocity, acceleration and rate of acceleration change in each of the main spindle and tool head. These determined values are compared with the respective thresholds. If they exceed the respective thresholds, the rate of selecting is changed. If the calculated values do not exceed the respective thresholds, the temporary X/C axes data is taken as modified X/C axes data. The machining will be carried out in accordance with the modified X/C axes data.

1. Field of the Invention
The present invention relates to working method and apparatus of grinding a workpiece and particularly a non-circular workpiece such as a cam or the like, the workpiece being fixedly mounted on a workpiece head and ground by a cutting tool which engages the outer periphery of the workpiece while being rotated with the main spindle or shaft.
2. Description of the Related Art
An NC cylindrical grinding machine which is adapted to work non-circular workpieces by a combination of the rotation of a main spindle with the reciprocation of a grinding head having a grinding wheel requires data relating to the movement of the grinding head relative to the rotational angle of the main spindle. Such data will be referred to "X/C axes data". The X/C axes data is calculated from the shape data representing the non-circular configuration of the workpiece, the diameter of the grinding wheel and the revolution speed of the workpiece. The right half A of FIG. 1 shows a method of grinding a workpiece 12 while it is being rotated at a constant velocity, in accordance with the X/C axes data so calculated. The left half B of FIG. 1 shows another method of grinding a workpiece while changing the rotational velocity of the main spindle to make the circumferential velocity of the workpiece constant, in accordance with the X/C axes data. When the rotational velocity of the workpiece is constant (A), the rotational angle .theta..sub.1 of the rotating workpiece per given time period is also constant. On the other hand, when the circumferential velocity of the workpiece is constant (B), the distant of movement r.sub.1 of a contact point between the tool and the workpiece per given time period is constant.
FIG. 2 is a block diagram illustrating the electrical arrangement usable in the method of grinding the workpiece while the rotation of the main spindle is maintained constant. The arrangement comprises a servo system section 70 for controlling various shafts, a RAM 72 for storing a working program and variables relating to the controlled shafts, and a ROM 73 for storing software relating to the control of the shafts, the software being read upon power ON of the system. Various data are processed by a main processor 71. When a servo processor 74 receives commands of shaft movement from the main processor 71, the servo processor 74 mainly controls the acceleration and deceleration of the shafts and gives the commands of shaft movement to drive units 75. Each of the drive units 75 supplies an electric drive power to the servo motor of the corresponding shaft.
In order to calculate the X/C axes data from the data of non-circular configuration provided by a non-circle data pre-processing section 30 considering the diameter of the grinding wheel as well as the time required for the work to complete one revolution, a RAM 37 is provided which comprises a shape data storage section 31, a grinder diameter storage section 32, a main spindle revolution storage section 33 and an X/C axes data storage section 38. A processor 54 is also provided which comprises a cam profile calculating section 50 for converting a group of given angle and lift points into profile data, and an X/C axes data calculating section 55 for calculating the position of the grinding head and the angle of the main shaft.
FIG. 3 is a block diagram showing another electric arrangement for changing the rotational velocity of the main spindle to make the circumferential velocity of the workpiece constant. Such an arrangement is only different from the arrangement of FIG. 2 in that the processor 54 shown in FIG. 3 comprises a circumferential cam length calculating section 51 for calculating the circumferential length of the cam, and a profile dividing point calculating section 52 for dividing the determined profile into segments having equal length.
Since the revolution speed of the main spindle is constant when the rotational velocity of the workpiece is constant as described, there will not be any delay of control on changing the rotational velocity of the workpiece. Thus, such a method can completely prevent any error from be produced due to variations of the revolution speed of the main spindle. However, the velocity of movement of the contact point between the workpiece and the cutting tool becomes uneven, resulting in irregular grinding. This further results in an uneven reaction against the cutting tool. As shown by C in FIG. 1, for example, a transitional portion from the base circle to the raised part will have a rapid increase in the movement of contact point. Thus, the cutting resistance and associated reactive force on the tool are increased with an adverse affect on the life of the tool. Further, the grinding time is also insufficient to obtain the desired grinding, resulting in production of non-worked parts. When the cutting resistance increases, the workpiece itself becomes deformed which prevents contact between the workpiece and the cutting tool. This produces non-ground parts of the workpiece, leading to errors in working.
On the other hand, since the grinding is constantly carried out when the circumferential velocity of the workpiece is constant, the cutting resistance may be maintained constant. Thus, the above problems relating to the life of the tool and the non-worked parts can be overcome. However, this creates some delay on controlling the revolution speed of the main spindle to increase changes in velocity and acceleration. This may generate a chatter mark on the ground surface of the workpiece. The chatter mark is a wavy pattern resulting in degradation of the quality of product.
In both the related art methods described, the non-circular configuration is approximated to a group of line segments having minute lengths. In other words, the end points (division points) of each of the line segments are determined to specify the configuration of a workpiece. However, since the configuration of the workpiece is inherently curved, the number of division points becomes huge making the working control and calculation more complicated.

Method and apparatus for grinding non-circular workpiece


An apparatus is disclosed comprising a first housing, a first display device connected to the first housing, a second housing, and a second display device connected to the second housing. The first housing may be connected to the second housing so that the apparatus can be placed into a first state and into a second state. In the first state the first display device lies on top of the second display device, so that only the first display device can be seen. In the second state the first display device and the second display device lie adjacent to one another and the first and the second display device can be seen simultaneously.

All cell phones typically use a display device to provide various types of useful information (e.g., phone numbers, caller IDs, signal strength, etc.) to the user of the cell phone. First-generation cell phones mostly used character-based displays. As the technology develops, most cell phones on the market of this invention use graphics-based displays, capable of displaying not only characters but also images including moving pictures.
Because of the small size of the portable devices preferred by most users of such devices, displays in these devices are necessarily very small. On the other hand, in the case of the third-generation (and next-generation) cellular systems, services available on such systems will evolve toward data-centric services including exchange of emails, stationary and moving pictures, as well as voice communications, providing true multimedia services.
Most of the current displays are very small for such multimedia applications. For example, one of the next generation multimedia services will be the broadcast TV service available on a cell phone. The current displays are, in general, too small for such services because people usually prefer to enjoy TV pictures on a bigger display.
A quick remedy of this problem of a too-small display of a cell phone for multimedia applications would be to simply use a bigger display. In this way, though, the size of the display could increase only up to the size of the phone.

Method of designing a size-adjustable multi-mode display unit for portable electronic devices


In a phase-change semiconductor device and methods of manufacturing the same, an example method may include forming a metal layer pattern on a substrate, the metal layer pattern including an opening that exposes a portion of the substrate, forming an etch stop layer on the metal layer pattern, a sidewall of the opening and the exposed portion of the substrate, the etch stop layer formed with a thickness less than an upper thickness threshold, and reducing at least a portion of the etch stop layer, the reduced portion of the etch stop layer forming an electrical connection with the substrate.

1. Field of the Invention
Example embodiments of the present invention relate to a semiconductor device and methods of manufacturing the same, and more particularly, to a phase-change semiconductor memory device and methods of manufacturing the same.
2. Description of the Related Art
Semiconductor devices such as dynamic random access memory (DRAM) devices, static random access memory (SRAM) devices, flash memory devices, etc. may be included in various electric and/or electronic apparatuses. Semiconductor devices may generally be classified as volatile memory devices or nonvolatile memory devices. Volatile memory devices may lose data stored therein when a power supply is turned off or drops below a voltage threshold, whereas nonvolatile memory devices may maintain data stored therein even after a power supply is turned off or drops below a voltage threshold. In an example, nonvolatile memory devices such as flash memory devices may be employed within digital cameras, MP3 players, cellular phones, etc., to maintain data integrity without a constant power supply.
Conventional flash memory devices may have longer read access and programming times as compared to random access memory (RAM) devices. A ferroelectric random access memory (FRAM) device, a magnetic random access memory (MRAM) device, a phase-change random access memory (PRAM) device, etc. may be employed which may have faster read access and programming times than flash memory devices.
Conventional PRAM devices may include a phase-change material which may alternate between a crystalline structure and an amorphous structure in accordance with heat generated by electrical power or current. An example of conventional phase-change materials which may be included in a PRAM device may include a chalcogenide alloy. The chalcogenide alloy may include a mixture of germanium (Ge), antimony (Sb) and tellurium (Te), and may be referred to as a "GST".
Conventional PRAM devices may include a phase-change layer configured to receive an electric current. A crystalline phase of the phase-change material may be adjusted based on a current level and a duration of the received electric current. Conventional PRAM devices may have a resistance which may vary based on a phase of the phase-change material, such that the crystalline and amorphous phases are each associated with different resistances. For example, the phase-change material in the crystalline phase may have a lower resistance than the phase-change material in the amorphous phase. The difference in the resistances of the crystalline and amorphous phases of the phase-change material may allow the PRAM device to be associated with one of a first logic level (e.g., a higher logic level) and a second logic level (e.g., a lower logic level). Examples of PRAM devices are well known in the art.
FIG. 1 is a cross-sectional view illustrating a phase change memory cell of a conventional PRAM device.
Referring to FIG. 1, the PRAM device may include a semiconductor substrate 10, an insulating interlayer pattern 11 formed on the semiconductor substrate 10, a contact plug 14 formed within the insulating interlayer pattern 11, a first insulation layer pattern 20a formed on the insulating interlayer pattern 11, a metal layer pattern 30a formed within the first insulation layer pattern 20a, a second insulation layer pattern 34b formed on the first insulation layer pattern 20a, a contact electrode 40a formed within the second insulation layer pattern 34b, a phase-change layer pattern 44a formed on the second insulation layer pattern 34b, an upper electrode 48a formed on the phase-change layer pattern 44a and a third insulation layer pattern 52a formed on the upper electrode 48a.
Referring to FIG. 1, the contact plug 14 may contact an impurity region (not shown) of the semiconductor substrate 10. The metal layer pattern 30a may contact the contact plug 14. The metal layer pattern 30a may electrically connect the contact electrode 40a to the contact plug 14. A spacer S may be formed within the second insulation layer pattern 34b to surround the contact electrode 40a.
Referring to FIG. 1, the metal layer pattern 30a may be formed by a damascene process such that a void V or a seam may be generated in the metal layer pattern 30a. The void V may be generated below the contact electrode 40a and/or the phase-change layer pattern 44a and may be characterized by a higher electrical resistance than other portions of the metal layer pattern 30a. The void V may at least partially isolate the contact electrode 40a from the metal layer pattern 30a.
Referring to FIG. 1, the metal layer pattern 30a may alternatively be formed by a dry etching process. In conventional dry etching processes, a hard mask pattern (not shown) may be formed on the metal layer 30a. The metal layer 30a may be dry-etched using the hard mask pattern as an etching mask. The dry etching process may reduce an occurrence of the void V in conventional PRAM devices.
Referring to FIG. 1, while the dry etching process may reduce an occurrence of voids, various problems may be associated with the above-described dry etching process. For example, the hard mask pattern (not shown) may remain on the metal layer pattern 30a with a thickness greater than about 3,000 Åafter the dry etching process. Thus, if the contact electrode 40a is formed through the hard mask pattern and the second insulation layer pattern 34b, the contact electrode 40a may not be formed with a desired resistance. The hard mask pattern and the second insulation layer pattern 34b, which may have uniform thicknesses, may thereby not be formed. The contact electrode 40a may not be uniformly formed at a given height through the hard mask pattern and the second insulation layer pattern 34b. Furthermore, a contact hole for forming the contact electrode 40a may not be formed through the hard mask pattern and the second insulation layer pattern 34b with higher levels of accuracy. The spacer S may also not be formed through the hard mask pattern and the second insulation layer pattern 34b. Accordingly, it may be more difficult to control an electrical current through the contact electrode 40a, which may degrade an operational performance of conventional PRAM devices.

Phase-change semiconductor device and methods of manufacturing the same


A hierarchical, distributed Availability Management (AM) process for recovering from component failures in a data processing system. The hierarchy of AM elements track a failure modality hierarchy of the data processing system components. For example, the system hierarchy may include system cards, processors, and processes, in which case the associated AM elements may be implemented at a card manager (CM) level, a system manager (SM) level, and a process manager (PM) level. The AM hierarchy is designed to achieve a failure granularity so that failures in the lower levels of the hierarchy have less of an impact on the entire system. Each AM element is responsible for receiving failure notifications from processing system components associated with a next lower level of the hierarchy. Upon such indication, if the AM element determines that the failed component may be restarted, if the failed component may be restarted, the AM element then determines if it can be hot, warm, or cold restarted and it does so without further notification or implication to system availability of other components. Hot restart requires complete integrity of sate information, warm restart causes a recovery of last known good state information, and a cold restart results in the re-initialization of state information. If, the component cannot be restarted, then notification is provided to the next higher level of the hierarchy and the AM element itself terminates. One of the AM processes may execute as an identity management protocol. The identity protocol sets a temporary master state; waits a predetermined amount of time; and then sets a final master state only if no other system card has asserted a temporary master state. The waiting time period is selected to be greater than the longest expected initialization process for peer components in the system.

With the development of cost effective data communications network infrastructures, such as IP-based data networks, it is increasingly common for such infrastructures to support mission critical data processing applications. So-called high availability computing systems originally developed for deployment in applications such as military, aircraft navigation, and telephone central office uses are now requirements in new deployments of these data communications networks. High availability is commonly achieved with redundant components such as redundant processors where failure modes result in a fail-over to a redundant component. High availability can also be achieved by rapidly recovering the failed components. Fast recovery of routing information in failure scenarios in network systems is important due to the relatively long time it takes to regenerate this information in large and complex networks.
The most stringent requirements for high availability demand continuous service with absolutely no loss of application state. These systems attempt to maintain a log of all transactions and their history; they are considered the domain of so-called fault tolerant computing. These computers often add redundancy to an extreme level as power supplies, hardened storage sub-systems, hardware subjected to stringent Mean Time Between Failure (MTBF) testing, and the like. Continuous availability, both during equipment failure and during subsequent return to service of repaired equipment, comes with a significant price and performance penalty.
High availability computing as presently practiced attempts to utilize the resources of redundant architectures. This solution can address the redundancy needed for components of systems, such as a networking device such as router, switch, or a bridge that is expected to serve a mission critical role in assuring that, for example, connections to many computers are maintained to the Internet. However, the class of errors typically detected in such systems is less comprehensive and the time to recover from such errors is typically much longer than in a true fault-tolerant machine architecture. As a result these architectures, even when they provide for fault recovery only after tens or hundreds of seconds, can be deployed for often at much less than the cost of traditional fault-tolerant computing systems.
The most often configuration is a so-called dual redundant architecture in which two data processing systems are deployed as an active-standby or master/non-master states. Hardware and/or software fail-over processes can be triggered by hardware, or software detectors, to cause an active or master process to be transferred to another active master process without operator intervention. Such application program fail-over typically requires that applications be restarted from the beginning, however, with the loss of all processing state not already committed to the secondary storage device such as a disk.
In an application such as a networking device, actively restarting the application in a functional processing node typically assumes the responsibility for reassigning, for example, the network addresses of the failed machine to the new processor, as well as rebuilding critical information such as routing tables. The transfer of network address and connection information can be typically handled quite easily and without complication.
As the size and complexity of data network increases, a router located deep within a network may have received its state information and constructed its routing table over the course of time. If router table state information is lost, it can be cumbersome and time-consuming to restart a router process and rebuild a router table. The information can only be restored by sending a long series of query and advertisement commands through routing protocols, such as an Interior Gateway Protocol (IGP) or an Exterior Gateway Protocol such as BGP-4. Upon the restart, it may thus take many seconds or even minutes, for router protocols to completely rebuild such tables.
Even more severe situations can occur where the rebuilding of the router table is not completed before real-time topology changes in the surrounding network occur. In such instances, the protocols may continuously reset themselves, thereby ultimately creating a race condition in that the process for rebuilding the router table never completes without some sort of manual intervention.
It desirable therefore for such systems to adopt certain high availability architectures, such as providing dual or backup power supplies, dual and separate system processor cards, and live insertion or "hot swap" capabilities that support replacement failed components without shutting down the entire system.


Digital signal processing (e.g. filtering) apparatus comprises pipelined digital signal processing means for generating each output sample of an output digital signal from input samples of an input digital signal by combining the input samples with a plurality of subsets of a set of filter coefficients associated with that output sample during a respective plurality of sample periods of the input digital signal; and coefficient generating means for supplying sets of filter coefficients to the signal processing means in response to the current state of a filter control signal. The coefficient generating means is operable to supply the plurality of subsets of each set of filter coefficients to the signal processing means during the respective plurality of sample periods of the input digital signal.

1. Field of the Prior Art
This invention relates to digital signal processing.
2. Description of the Prior Art
Digital signal processing devices, such as digital filters, are used to perform signal processing operations on digital representations of sampled analogue signals such as audio signals. A typical application of such a device for use with a digital audio signal is to provide a frequency-dependent gain adjustment, such as a low-pass, band-pass or high-pass filtering operation.
FIG. 1 is a schematic diagram of a previously proposed digital filtering apparatus in which the characteristics (e.g. frequency response or gain) of a digital filter are dependent on the position of a user-operated control, such as a potentiometer. The apparatus of FIG. 1 may form part of, for example, a digital audio mixing console.
In FIG. 1, the analogue position of a potentiometer 10 is detected by a position encoder 20. The position encoder 20 generates a digital position signal 25 representing the position of the potentiometer 10 at regular intervals determined by clock pulses of a sampling clock signal 28. The digital position signal 25 is then passed to a coefficient generator 30 which produces successive sets of filter coefficients 35 (to be convolved with samples of a digital audio signal) in dependence on the current value of the digital position signal 25. Similar position sampling operations are performed in parallel by further position encoders (e.g. an encoder 21) based on the positions of further potentiometers (e.g. a potentiometer 11).
In order to produce the required filter coefficients, the coefficient generator 30 is programmed with data representing the function assigned to the potentiometer 10. For example, the potentiometer 10 may be a simple "gain" control, in which case the coefficient generator 30 generates a set of coefficients 35 which map an increment or decrement in the digital position signal 25 onto a corresponding increment or decrement in the gain of a digital filter using those coefficients 35. The coefficient generator 30 generates a new set of coefficients 35 at regular intervals, being synchronised by clock pulses of a coefficient update clock 38.
In the example shown in FIG. 1, the coefficient generator in fact generates more than one set of coefficients at a time, with each set of coefficients (e.g. a set 36) corresponding to the output of a respective position encoder.
The successive sets of coefficients 35 are supplied to a signal processor 40 which receives an input digital audio signal 42 (e.g. a 44.1 kilohertz or 48 kilohertz 16 bit digital audio signal) and, using the current set of coefficients 35, generates an output filtered digital audio signal 44. For reasons which will be explained below, some of the coefficients 35 are delayed within the signal processor 40 by a delay element 46. The signal processor also receives the further sets of coefficients 36 etc, and performs further processing of the input digital audio signal 42 using those sets of coefficients.
FIG. 2 is a schematic diagram illustrating the operation of the signal processor 40 of FIG. 1.
The signal processor 40 is a pipelined processing device. This means that the signal processor 40 receives a sample of the input digital audio signal 42 in each sample period of the digital audio signal and supplies an output sample of the output digital audio signal 44 at each sample period. However, the processing required to generate an output sample is performed over the course of more than one sample period. This pipelined arrangement is represented schematically in FIG. 2, in which time is represented along the horizontal axis and a number of discrete processing streams within the signal processor 40 (e.g. separate central processing units or CPUs operating in parallel) are represented on the vertical axis.
In FIG. 2 the processing applied to a particular input sample (sample "n") is represented by shaded portions 50, 52 and 54. When sample n is received by the signal processor 40, it is initially processed at various times during a first sample period in a subset of the processing streams represented by the shaded portion 50. In the following sample period the processing of sample n is represented by the shaded portions 52 (the portion 50' in the second sample period illustrated being used to process the next sample n+1). Finally, in the third sample period illustrated in FIG. 2, the processing continues as represented by a shaded portion 54, before the filtered sample n is output by the signal processor 40.
FIG. 3 is a schematic diagram of an infinite impulse response (IIR) digital filter which may be embodied in the signal processor 40. This type of filter is conventional and is described in, for example, the book "Digital Signal Processing" (Proakis and Manolakis, MacMillan Publishing Company, 1992). In this type of filter, an input signal is delayed by successive delay elements (Z.sup.-1) with the output of various "taps" in the change of delay elements being multiplied by respective filter coefficients c1-c5. The results of the multiplication stages are summed by an adder 60 to generate the filtered output signal.
When a filter of the type illustrated in FIG. 3 is implemented in a pipelined signal processor 40 of the type described above, constraints on the number of processing operations which can be performed during a single sample period often mean that it is impossible to schedule all of the multiply operations used in the generation of a single filtered output sample (i.e. using a single set of coefficients such as the set 35) to take place during the same sample period. This situation is illustrated in FIG. 4, which is a further schematic timing diagram illustrating the operation of the signal processor 40 of FIG. 1.
In FIG. 4, the five multiply operations required to implement the filter of FIG. 3 are split between two successive sample periods 70, 72. In particular, the multiply operations for coefficients c1-c3 of a particular coefficient set are implemented in the sample period 70 and the multiply operations for the coefficients c4 and c5 of that same coefficient set are implemented in the sample period 72.
When the filter response has to be changed (e.g. because the potentiometer 10 has been moved by the user), it is important that all of the filter coefficients c1 to c5 are changed for effectively the same output audio sample, so that the situation does not arise that half of a filtering operation is carried out using one version of a particular set of coefficients and half using an updated version of that set. However, the coefficient generator 30 generates a complete set of coefficients 35 in parallel and at the same time, so this has meant that in the previously proposed apparatus of FIG. 1 a subset of the coefficients has to be delayed so that a particular filtering operation can be completed using a single version of the set of coefficients 35.
In FIG. 4, this situation is illustrated schematically in that a clock pulse (CU) of the coefficient update clock 38 occurs between the sample period 70 and the sample period 72. This means that the current set of coefficients 35 output by the coefficient generator 30 during the sample period 70 is, say, coefficient set (version) n and the set of coefficients output during the sample period 72 is, say, a different coefficient set (version) n+1. The multiplications by coefficients c1 to c3 take place using the coefficient set n during the sample period 70. However, in order that the remaining multiplications (by c4 and c5) are performed using coefficient set n rather than coefficient set n+1, the coefficients c4 and c5 have to be delayed during the sample period 70 for use during the sample period 72.
The situation described above, in which the coefficient generator 30 generates a plurality of complete sets of coefficients 35, 36 together and in parallel but some of those coefficients have to be delayed by the signal processor 40 for use in subsequent sample periods, is wasteful of the available processing resources because (a) the coefficient generator 30 is working needlessly fast, and (b) the implementation of the delay within the signal processor occupies a part of the limited processing and memory resources of the signal processor 40.


A multi guard ring structure for a reach-through type semiconductor device has at least first and second guard ring regions. The first guard ring region surrounds a main region with a predetermined first spacing. The second guard ring region surrounds the first guard ring region with a predetermined second spacing. To improve the ability to withstand reverse bias voltage, the second spacing between the first and second guard ring regions is made smaller than the first spacing between the main region and the first guard ring region in order that a maximum value of an electric field strength at a junction between the first guard ring region and the drift region may be equal to or lower than 85% of a maximum value of a field strength at the main junction at the avalanche breakdown condition of the main junction.

The present invention relates to a guard ring structure for a reach-through type high voltage semiconductor device.
There are two conventional guard ring structures.
A first conventional guard ring structure has equally spaced four annular guard ring regions surrounding a main region located at the center. Spacings among the main region and the guard ring regions are all equal to a predetermined value L. Four equal inter-region spacings are; a first spacing between the main region and the first nearest guard ring region, a second spacing between the first nearest guard ring region and the second nearest guard ring region, a third spacing between the second guard ring region and the third guard ring region, and a fourth spacing between the third guard ring region and the fourth guar ring region. The main and guard ring regions are p type regions formed in an n type drift layer formed on an n.sup.+ type substrate layer. The main region forms a main pn junction with the drift layer. An anode electrode is connected with the main region, and a cathode electrode is connected with the substrate layer. The guard ring regions are connected with no electrodes.
The main and guard ring regions are formed by thermal diffusion from the semiconductor surface through diffusion windows. Hence, each diffused region has a cross sectional shape which is round at each corner. In the case of a reach-through type, a depletion region produced from the main junction by application of a reverse bias extends fully across the drift layer and reaches the substrate layer at a voltage level lower than a reverse bias voltage at which an avalanche breakdown occurs at the main junction. For example, the drift layer is formed to have a thickness of about 50 .mu.m and an impurity concentration of about 1.times.10.sup.14 /cm.sup.3 to obtain a breakdown voltage of about 600 V.
The guard ring structure functions as follows:
The anode electrode 20 is grounded, and a positive potential is applied to the cathode electrode 21. Under these conditions, the junction between the p type main region and the n type drift region is reverse-biased, and a depletion layer extends into the drift region 5 whose impurity concentration is low to obtain a high breakdown voltage. The junction between the main region and the drift layer has a curved portion as well as a planar portion. The curved junction portion has a higher field intensity than the planer portion. Therefore, without the guard ring regions, an avalanche breakdown would occur at the curved junction portion at a reverse bias voltage lower than a breakdown voltage expected from the planar junction.
The first guard ring region near the curved main junction portion mitigates an increase of the electric field in the lateral direction when the cathode potential increases and the depletion region from the main region reaches the first guard ring region. With a further increase in the cathode potential, the depletion region starts extending from the first guard ring region. In this way, the guard ring structure acts to reduce electric field crowding, and to improve the withstand strength.
The equally spaced multi guard ring structure is easy in design, and capable of making a maximum field intensity of a surrounding guard ring region lower than a maximum field intensity of an inner region. The maximum field intensity of the first guard ring region is lower than that of the main region, and the maximum field intensity of the outer guard ring region is lower than that of the inner guar ring region. The outermost guard ring region is an exception. However, the guard ring structure is arranged to have such properties by increasing the number of guard rings or other measures.
When the spacing between the main region and the first guard ring region is reduced, the effect of mitigating the field strength at the curved main junction portion is increased, and the region at which the electric field is maximum in the main region is shifted in the curved portion toward the planar junction portion. Therefore, a reduction of the spacing between the main region and the first guard ring region improve the breakdown voltage of the main junction. However, too narrow a spacing causes a disadvantageous effect as explained later.
A second conventional multi guard ring structure is shown in B. J Baliga "MODERN POWER DEVICES", John Wiley & Sons. Inc., page 99, FIG. 3.26. In a p type drift layer, there are formed an n.sup.+ type main junction region, an n.sup.+ type first guard (or field) ring region surrounding the main junction region with a first spacing from the main junction region, an n.sup.+ type second guard ring region surrounding the first guard ring region with a second spacing from the first guard ring region, and an n.sup.+ type third guard ring region surrounding the second guard ring region with a third spacing from the second guard ring region. In this structure, the guard ring spacing together with the guard ring width is decreased with an increase in the distance from the main junction region. This structure causes a depletion region to extend gradually from an end portion of the main junction region in the lateral direction. The guard ring width is decreased in the lateral direction away from the main junction region so that an outer guard ring is narrower than an inner guard ring. Therefore, the depletion layer depth is gradually decreased along the lateral direction away from the main junction region, underneath the gradually narrowed guard ring regions. This design can save space at the device periphery. As explained in this document, the guard ring regions share the applied voltage equally in the ideal case, and avalanche breakdown is produced at the outer edges of all the guard ring regions simultaneously. However, this structure is a non-reach-through structure in which a depletion layer from the main junction region does not reach the bottom of the p type drift layer.


A single-ended sense amplifier, for fast sensing from a precharged low condition, is provided. In the precharge mode, the amplifier discharges the sensing node to ground, and charges a bias node to a first predetermined voltage. This bias node modulates the current drive capabilities of the first and second charge transistors. Once the sense amplifier enters the sensing mode, the voltage at the bias node causes the first charge transistor to rapidly supply a substantial amount of current to the sensing node. If the selected memory cell is in the conducting state, the voltage at the sense node is discharged to ground and the amplifier output is a low-voltage, indicating the detection of a logic "0" state. Conversely, if the selected memory cell is in a non-conducting state, the voltage at the sense node increases beyond a second predetermined voltage, and the amplifier output is a high-voltage, indicating the detection of a logic "1". The amplifier design eliminates the requirement for depletion mode transistors and the typical precharge/discharge scheme associated with their use. Accordingly, the self-biased sensing structure optimizes sensing speed, while reducing the power consumption of the amplifier.

Single-ended sense amplifiers are widely used in memory and microprocessor circuits for reading (sensing) the logic state of memory cells. In a conventional memory circuit, the memory cells are configured as an array of rows and columns, wherein the presence or absence of a transistor in a memory cell represents the stored bit at the respective memory cell location. The sense amplifier, coupled to the column of the memory cell to be read, detects whether the memory is in a conducting or non-conducting state. If the selected memory cell in the column is in a conducting state, the sense amplifier detects a logic "0", and conversely, the sense amplifier detects a logic "1" when the memory cell is in a non-conducting state.
High-performance microprocessors, utilizing on-chip ROMs for storage of operational information, require high-speed sense amplifiers for fast sensing of data. In many cases, these high-performance microprocessor designs use on-chip ROMs with numerous output lines. While fast sensing is particularly desirable in these microprocessor environments, efficient utilization of chip area and reduction of the power consumption attributable to the amplifier are also design goals. Some amplifiers designed for use in microprocessor circuits employ double-ended, differential amplifiers for fast sensing of data. These double-ended sense amplifiers typically require more devices than single-ended amplifiers, and consequently the chip area required is larger. Moreover, the double-ended amplifiers generally require more DC current for their operation. Consequently, double-ended sense amplifiers are often infeasible for use in high-performance microprocessor circuits.
The implementation of single-ended sense amplifiers typically requires less chip area, therefore these amplifiers are generally more suitable for use in microprocessor circuits with on-chip memory. In the prior art there are single-ended sense amplifiers which require precharge/discharge circuitry for their operation. The precharge/discharge scheme may consume a significant amount of power, and conceivably degrades the performance of the microprocessor circuit. Furthermore, these sense amplifier designs have required depletion devices, which require additional processing steps for their fabrication.

Sensing structure for single ended input