Abstract:
Methods for producing a multifilament Nb3Sn superconducting wire having a Jc value of at least 2000 A/mm2 at 4.2 K and 12 T by a) packing a plurality of Cu encased Nb rods within a first matrix which is surrounded by an intervening Nb diffusion barrier and a second matrix on the other side of the barrier remote from the rods thereby forming a packed subelement for the superconducting wire; b) providing a source of Sn within the subelement; c) assembling the metals within the subelement, the relative sizes and ratios of Nb, Cu and Sn being selected such that (i) the Nb fraction of the subelement cross section including and within the diffusion barrier is from 50 to 65% by area; (ii) the atomic ratio of the Nb to Sn including and within the diffusion barrier of the subelement is from 2.7 to 3.7; (iii) the ratio of the Sn to Cu within the diffusion barrier of the subelement is such that the Sn wt %/(Sn wt %+Cu wt %) is 45%-65%; (iv) the Cu to Nb local area ratio (LAR) of the Cu-encased Nb rods is from 0.10 to 0.30; (v) the Nb diffusion barrier being fully or partially converted to Nb3Sn by subsequent heat treatment; and (vi) the thickness of the Nb diffusion barrier is greater than the radius of the Nb portions of the Cu encased Nb rods; and d) assembling the subelements in a further matrix and reducing the assemblage to wire form such that (i) the multifilamentary Nb3Sn superconducting wire is formed of a plurality of the subelements, each having a Nb diffusion barrier to thereby form a wire having a distributed barrier design; (ii) the Nb portions of the copper encased Nb rods in the final wire are of diameter from 0.5 to 7 μm before reaction, and (iii) the Nb diffusion barrier that is fully or partially converted to Nb3Sn by heat treatment is from 0.8 to 11 μm thickness before reaction; and e) heat treating the final size wire from step d) to form the Nb3Sn superconducting phases, and multifilament Nb3Sn superconducting wires made thereby are described herein.
Abstract:
A device and method for use as an adjunct in assuring that a manufactured wire is substantially free of internal flaws. A plurality of successively adjacent wire bending stations are provided, where each station includes means for bending the wire into bending planes which are different for each of the stations. The wire is passed through the successive stations, whereby the different bending planes at each station subject the wire at each station to tensile bending strain at portions of the wire cross-section which are different for each station. As a result the probability is increased that a given internal flaw in the wire will be exposed to the tensile bending strain condition as the wire passes through the successive stations, increasing likelihood of breakage of the wire at the flaw or of flaw magnification to improve detection of the flaw during subsequent wire inspections.
Abstract:
Critical current densities of internal tin wire having values of at least 2000 at temperature of 4.2 K and in magnetic field of 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; and barrier thickness relative to the filament thickness; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.
Abstract:
Critical current densities of internal tin wire to the range of 3000 A/mm2 at temperature of 4.2 K and in magnetic field 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; barrier thickness relative to the filament thickness; additions of a dopant such as Ti or Ta to the Nb3Sn; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.
Abstract translation:通过在分布式屏障子元件设计中控制以下参数,可以实现在4.2K温度和磁场12 T范围内的3000 A / mm 2范围内的内部锡线的临界电流密度:wt% 锡青铜 原子Nb:Sn; 当地面积比; 可反应的屏障; 屏障厚度相对于灯丝厚度; 向Nb 3 Sn添加诸如Ti或Ta的掺杂剂; 以及用于重新排列和减少线材的设计,以控制随后的热反应阶段的最大长丝直径。
Abstract:
A packet timing method and apparatus for use with a system for controlling digital TV program start time. An encoder inserts a program clock reference (PCR) timing field, in at least two intervals in transport packets. A decoder generates a decoder-clock signal from the PCR timing signal, which has the same frequency as an encoder-clock signal used for encoding. In response to the PCR timing field, a rate of consumption of data is synchronized with a rate of production of data, and chroma sub-carrier is synchronized.
Abstract:
A video system for providing a large number of video streams. The video system includes a video server and dividing means. Storage means, a switch and control means are located at the video server. The video server has a plurality of central-processing units (CPUs). The dividing means divides a plurality of input video-streams entering the video system, and sends the divided plurality of input-video streams, with each divided video stream identified with a separate Ethernet address, to the video server. The storage means stores an input video-stream of the plurality of input video-streams as a stored-video stream. The switch routes an input-video stream of the plurality of input-video streams to the storage means. The control means controls the storage means to replay the stored-video stream and to control portions of the stored-video stream at an appropriate time, and controls the plurality of CPUs at the video server to work in parallel.
Abstract:
Web pages and other Internet information resources are retrieved from a one-way broadcast signal such as a broadcast television signal. A user selects from a range of available information, including hypertext markup language (HTML) pages, which is carried in the broadcast stream by invoking a command which is defined according to a uniform resource locator (URL) format. Table mapping data is carried in the broadcast signal and provides a broadcast address corresponding to the URL of the user request signal for use in identifying a location in the broadcast signal from which the desired information can be retrieved. The broadcast address may provide information regarding a frequency, packet identifier, satellite, transponder, cryptographic scheme, modulation scheme, data rate, error correction scheme, page number or other relevant criteria associated with the broadcast signal which must be known to retrieve the requested information. The system has the look and feel of a two-way Internet connection, and is compatible with existing transmission schemes.
Abstract:
A system for managing trading orders comprises a memory operable to store a first order associated with a particular trading product, wherein the first order is associated with a first price comprising a first root value. The system further comprises a processor communicatively coupled to the memory and operable to receive a second order associated with the particular trading product. The second order is associated with a second price; and the second price comprises a second root value and a particular fractional pip value. The processor is further operable to disclose the first root value and the second root value while suppressing the particular fractional pip value.
Abstract:
A method for generating a wide range of clock rates from a single clock. A delta is generated from a first clock signal and a second clock signal. An accumulative offset is generated from adding the delta to a previous accumulative offset for each clock period of the first clock signal. Whenever an overflow is encountered, the value of the accumulative offset is truncated. The second clock signal is interpolated between adjacent values.
Abstract:
A system for the delivery of video on demand (VOD). A wireless remote control device generates keystroke signals for controlling a TV display and has a single button for restarting a selected program at a beginning of the selected program. A head-end unit supports separate downstream virtual channels for each separate TV set connected on a common TV feeder-cable; The head-end unit locally records and stores many programs, and transmits each program using a compressed digital format. The Compressed digital format may use MPEG-2 or MPEG-4. The head-end unit has means for protecting against signal theft. A set top unit encapsulates the keystroke signals and transmits the keystroke signals via a two-way channel to the head-end unit.