Analysis of XANES for identification of highly dispersed transition metal oxides on supports

XANES of vanadium and niobium oxide on silica or alumina have been analyzed quantitatively by a deconvolution technique. Based on the results for reference compounds, local structures of supported vanadium and niobium species were identified. The composition was estimated from difference spectra for the samples which consisted of two kinds of species.     

A novel method of suppressing the inrush current of transformers by using a series‐connected voltage‐source PWM converter

This paper proposes a novel method of suppressing the inrush current of transformers. A small‐rated voltage‐source PWM converter is connected in series to the transformers through a matching transformer. As the connected PWM converter serves as a resistor for the source current, no inrush phenomena occurs. The required rating of the PWM converter, which serves as the damping resistor for the inrush phenomena, is 1/400 that of the main transformers in single‐phase circuits. In three‐phase circuits, it is 1/900. The basic principle of the proposed method is discussed. Digital computer simulation is implemented to confirm the validity and excellent practicability of the proposed method using the PSCAD/EMTDC. A prototype experimental model is constructed and tested. The experimental results demonstrate that the proposed method can perfectly suppress the inrush phenomena. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(4): 56–65, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20174     

A parallel algorithm for time-slot assignment problems in TDMhierarchical switching systems

The paper presents a parallel algorithm for time-slot assignment problems in TDM hierarchical switching systems, based on the neural network model. The TDM systems are operated in repetitive frames composed of several time-slots. A time-slot represents a switching configuration where one packet is transmitted through an I/O line. The goal of the algorithm is to find conflict-free time-slot assignments for given switching demands. The algorithm runs on a maximum of n²×m processors for m-time-slot problems in n×n TDM systems. In small problems up to a 24×24 TDM system, the algorithm can find the optimum solution in a nearly constant time, when it is performed on n²×m processors     

A video codec LSI for high-definition TV systems withone-transistor DRAM line memories

A video codec LSI for high-definition television (HDTV) systems has been developed. By using a time-compressed integration encoding technique, it converts a 20.0-MHz bandwidth luminance signal and two 5.0-MHz chrominance signals into a compressed image signal at 48.6-MHz sampling frequency. It is useful in many HDTV application systems, such as 400-Mb/s digital transmission system, a video disk player system, or an analog transmission system. Over 288000 elements, including a 52-kb one-transistor DRAM (dynamic random access memory) line memory specially developed for this LSI, were integrated on a 12.16×12.10-mm² chip. A standard cell layout method and a 1.2-μm CMOS logic LSI process were used     

面向可重构扫描网络的锁定隔离安全结构

为使可重构扫描网络免受未经授权的访问、恶意仪器对传输数据的窜改和嗅探3种安全攻击的影响,提出了锁定隔离安全结构.该结构首先把彼此不具有安全威胁的仪器分成一组,通过控制隔离信号实现组与组之间的单独访问,以防止恶意仪器对传输数据的窜改和嗅探.然后通过使用锁段插入位保护关键的仪器,只有扫描网络中处于特定位置的多个键值被设置成特定值(0,1序列)时锁段插入位才能打开,能加大未经授权访问的难度.此外,为解决仪器分组多导致硬件开销大和布线困难的问题,提出了仪器分组算法,根据仪器间的安全关系构建无向图,然后对无向图求极大独立集,能有效地减少仪器分组数.在ITC 02基准电路上的实验结果表明,与国际上同类方法相比,所提的安全结构打开锁段插入位所需要的时间增大了7倍,在面积、功耗和布线上的平均减少百分比分别为3.81%,9.02%和4.55%.     

基于三态信号的改进游程编码压缩方法

为提高集成电路测试效率,提出一种结合三态信号的改进游程编码压缩方法。先对原始测试集进行部分输入精简处理并填充测试集的无关位,再对经过预处理的测试集根据游程长度进行变长分段处理找出最优段长。按照游程长度的出现频率对最优段长下的参考位设置编码表进行编码压缩,使用三态信号编码标志位并将编码压缩后的测试集存入自动测试设备（ATE）,最终通过设计解压电路对ATE中存储的压缩数据进行无损解压。实验结果表明,在硬件开销未明显增加的情况下,该方法的测试数据平均压缩率达到74.39%,优于同类压缩方法。     

0Cr13Ni5Mo+Q345异种钢焊接工艺

介绍了一种新型焊接材料SW—309L超低碳不锈钢药芯焊丝用于0Crl3Ni5Mo Q345异种钢焊接。从母材性能、焊接材料的选择、焊接工艺评定等方面予以详细地分析和验证。     

Improved mechanical properties in dissimilar Ti-AISI 304L joints

The effect of low temperature post weld heat treatment on the tensile strength and bend test properties of dissimilar friction welds between titanium and AISI 304L stainless steel joints is investigated. Post weld heat treatment at temperatures less than 873 K has no effect on joint tensile strength properties, but markedly improves bend test properties. The highest bend angle is produced using a post-weld heat treatment at 773 K for 1 h (the Larson-Miller parameter corresponding to this treatment is 15.5×10³ K h^–1). Low temperature heat treatment improves bend ductility, because stress relaxation occurs with minimal increase in the transition region width at the bondline region. Dissimilar joint bend testing properties decrease markedly when the width of the transition region exceeds 1–2 m. An explanation for the detrimental effect of thick transition regions at the joint interface region on the mechanical properties of dissimilar joints is proposed. It is suggested that the development of significant triaxial stress due to the constraint imposed by large, needle-shaped intermetallic particles promotes premature joint failure in joints containing thick transition regions.     

A blog emotion corpus for emotional expression analysis in Chinese

Weblogs are increasingly popular modes of communication and they are frequently used as mediums for emotional expression in the ever changing online world. This work uses blogs as object and data source for Chinese emotional expression analysis. First, a textual emotional expression space model is described, and based on this model, a relatively fine-grained annotation scheme is proposed for manual annotation of an emotion corpus. In document and paragraph levels, emotion category, emotion intensity, topic word and topic sentence are annotated. In sentence level, emotion category, emotion intensity, emotional keyword and phrase, degree word, negative word, conjunction, rhetoric, punctuation, objective or subjective, and emotion polarity are annotated. Then, using this corpus, we explore these linguistic expressions that indicate emotion in Chinese, and present a detailed data analysis on them, involving mixed emotions, independent emotion, emotion transfer, and analysis on words and rhetorics for emotional expression.