改善PZT微位移器线性的一种方法

根据锆钛酸铅压电陶瓷的逆压电效应。设计了以８０３１单片机为核心的压电陶瓷堆微位移器提高了ＰＺＴ的线性，从而满足了在天文自适应系统中所要求的精确微位的应用。     

Long-term progression in chronic manganism: ten years of follow-up

We studied the long-term clinical course of five patients with chronic manganese intoxication. The mean scores of the King's College Hospital Rating Scale for Parkinson's disease increased from 15.0 +/- 4.2 in 1987 to 28.3 +/- 6.70 in 1991 and then to 38.1 +/- 12.9 in 1995. The deterioration was most prominent in gait, rigidity, speed of foot tapping, and writing. Tissue concentrations of manganese in blood, urine, scalp hair, and pubic hair returned to normal. Follow-up MRIs did not show paramagnetic high-signal intensity on T1-weighted images. The data indicate that clinical progression in patients with manganese parkinsonism continues even 10 years after cessation of exposure.     

面向对象机器翻译知识库IMT—KB的设计与实现

机器翻译知识库是机译系统的重要组成部分,针对传统机译知识库的不足之处,本文提出一种面向对象的机译知识体系结构,同时给出这种具有层次性和模块性机译知识库的存储组织和管理机制。     

Self-stabilizing depth-first token circulation on networks

Summary This paper proposes a self-stabilizing protocol which circulates a token on a connected network in nondeterministic depth-first-search order, rooted at a special node. Starting with any initial state in which the network may have no token at all or more than one token, the protocol eventually makes the system stabilize in states having exactly one circulating token. With a slight modification to the protocol —by removing nondeterminism in the search — a depth-first-search tree on the network can be constructed. The proposed protocol runs on systems that allow parallel operations. Shing-Tsaan Huang was born in Taiwan on September 4, 1949. He got his Ph.D. degree in 1985 from Department of Computer Science, University of Maryland at College Park. Before he pursued his Ph.D. degree, he had worked several years in the computer industry in Taiwan. Professor Huang is currently the chairman of the Department of Computer Science, Tsing Hua University, Taiwan, Republic of China. His research interests include interconnection networks, operating systems and distributed computing. He is a senior member of the IEEE Computer Society and a member of the Association for Computing Machinery. Nian-Shing Chen was born in Taiwan on October 21, 1961. He received his Ph.D. degree in computer science from National Tsing Hua University in 1990. Dr. Chen is currently an associate professor with the Department of Information Management at Sun Yat-Sen University of Taiwan. His research interests include distributed systems, computer networks, computer viruses and expert systems. He is a member of IEEE and Phi Tau Phi honorary society.This research is supported by National Science Council of the Republic of China under the contract NSC81-0408-E-007-05 and NSC82-0408-E-007-027     

Synthesis of large building blocks for dendritic polyethers

Summary Building blocks containing multi-aryl ethers linkage in larger size for rapid building larger dendrimers were prepared with 3,5-di(4-hydroxyphenoxy)benzyl alcohol (1) as branch monomer and 1,3,5-tri(4-hydroxyphenoxy)benzene (2) as core molecule. Two generation of dendritic polyethers (12 and 15) were obtained by Fréchet convergent approach with 3,5-diphenoxybenzyl bromide (3) as starting molecule. They were characterized firstly by ¹H-NMR, ¹³C-NMR, and MS.     

蒸发冷凝法中气体压强和蒸发温度对粒子大小的影响

在Ｎ＿２气氛中，用蒸发冷凝法，制备了Ｓｎ细微粒和Ｆｅ及Ｆｅ－４７（ｗｔ）％Ｎｉ合金超细微粒。分别用ＳＥＭ和ＴＥＭ，直接观测粒子大小及其分布。结果表明，平均粒径不是随Ｎ＿２气压强增加单调上升，而是在某一压强Ｐ＿（ｍａｘ）下，出现最大值。随蒸发温度提高，Ｐ＿（ｍａｘ）值迅速增大。粒子大小及其分布与粒子生长机制密切相关。对粒子凝聚生长条件进行了简要讨论。     

An intelligent sensor for detection of milling chatter

In this paper, a new real-time sensor system has been developed to detect chatter in milling operations. In the developed sensor system, a pattern recognition technique based on an unsupervised neural network using the adaptive resonance theory (ART) is adopted for detection of milling chatter. The features on the cutting force spectrum are fed into the sensor system to classify the milling process with or without chatter. The experimental results indicate that the proposed sensor system can accurately detect milling chatter regardless of the variation in cutting conditions.     

LOW-CYCLE FATIGUE UNDER NON-PROPORTIONAL LOADING

A series of strain-controlled, low-cycle fatigue experiments have been conducted on 42CrMo steel under various loading paths including circular, square, cruciform, and rectangular paths. Present experiments have shown that there is additional hardening under non-proportional cyclic loading. Non-proportional cyclic additional hardening also results in a shorter life for multiaxial low cycle fatigue. A non-proportionality measure of strain path based on both a physical basis and macromechanical phenomena is proposed. The loading path effect on additional hardening is also described well. Low-cycle fatigue damage accumulation and the evolution process under non-proportional loading is analysed via the Continuum Damage Mechanics Model of Chaboche. A non-proportinality measure is introduced in the damage evolution equation and a modified Coffin-Manson type formula is derived. A novel fatigue life prediction approach based on the critical-plane concept of Brown and Miller is proposed.     

ZSM-5型沸石催化剂的结焦与失活

本文对ZSM-5型沸石催化剂结焦与失活的关系进行了系统的评述.探讨了ZSM-5沸石的酸度和微孔结构对结焦过程的影响.