TiO_2粉体性能对PTC热敏电阻性能的影响

ＴｉＯ_２的纯度、粒度及粒形对ＢａＴｉＯ_３系ＰＴＣＲ的性能影响很大，对所用ＴｉＯ_２加以选择非常重要，国产和日本产ＴｉＯ_２原料在粉体性能上存在差异。     

全局最小均方算法

本文提出了一种基于全局均方误差最小准则的全局最小均方（ＴＬＭＳ）算法，在理论上分析了它的统计特性和收敛性，用数字仿真技术优良地它的性能。     

MIS型单晶硅液晶光阀

详细介绍了一种新颖、快速响应的金属－绝缘层－半导体构成的MIS型单晶硅液晶光阀的结构、工作机理、制作工艺和性能参数测试。液晶采用45°扭曲向列型混合场效应工作模式。所得到的光阀的极限分辨率为40lp／mm，口径40mm，最大对比度＞100：1，在930nm（△λ＝40nm）写入光灵敏度为20μW／cm2，响应时间为15ms。报道了该光阀在大屏幕投影显示中的应用。     

Temperature dependence study of two-dimensional electron gas effecton the noise performance of high frequency field effect transistors

We present experimental evidence that the noise figure (NF) and associated gain equal to those achieved with GaAs pseudomorphic high electron mobility transistors (GaAs p-HEMT's) can also be accomplished by ion implanted GaAs metal-semiconductor field-effect transistors (GaAs MESFET's). These measured noise figure results as a function of low temperature for GaAs MESFET's and p-HEMT's clearly suggest that the transport properties of the two-dimensional electron gas in HEMT's and p-HEMT's do not make a significant contribution to the noise reduction at high frequency operation of these devices     

Multilevel barrel shifter for CORDIC design

The coordinate rotation digital computer (CORDIC) algorithm is used in numerous special purpose systems for real-time signal processing applications. It uses barrel shifters to complete shift operations. However, the barrel shifter occupies most of the area of the CORDIC chip. A new structure of multilevel barrel shifters is presented. With this structure the shifter size is reduced by 68%. The novel structure can also slightly reduce the latency time of shift operations     

用于X光激光实验的反射式线聚焦光学系统的设计和分析

基于三维光线追迹的象差计算,对卢瑟福实验室用离轴球面反射线聚焦系统作了分析。然后,首次提出了用于X光激光实验的两类新的反射式线聚焦构型,即反射式光楔列阵和光锥列阵系统,并作了计算。最后,对所得结果作了比较和讨论。     

Polyamine analogue regulation of NMDA MK-801 binding: a structure-activity study

A series of analogues and homologues of spermine were synthesized, and their impact on MK-801 binding to the N-methyl-D-aspartate (NMDA) receptor was evaluated. These tetraamines encompass both linear and cyclic compounds. The linear molecules include norspermine, N1, N11-diethylnorspermine, N1,N12-bis(2,2,2-trifluoroethyl)spermine, homospermine, and N1,N14-diethylhomospermine. The cyclic tetraamines consist of the piperidine analogues N1,N3-bis(4-piperidinyl)-1,3-diaminopropane, N1,N4-bis(4-piperidinyl)-1,4-diaminobutane, N1,N4-bis(4-piperidinylmethyl)-1,4-diaminobutane, and N1,N4-bis[2-(4-piperidinyl)ethyl]-1,4-diaminobutane and the pyridine analogues N1,N3-bis(4-pyridyl)-1,3-diaminopropane, N1,N4-bis(4-pyridyl)-1,4-diaminobutane, N1,N4-bis(4-pyridylmethyl)-1,4-diaminobutane, and N1,N4-bis[2-(4-pyridyl)-ethyl]-1,4-diaminobutane. This structure-activity set makes it possible to establish the importance of charge, intercharge distance, and terminal nitrogen substitution on polyamine-regulated MK-801 binding in the NMDA channel. Four families of tetraamines are included in this set: norspermines, spermines, homospermines, and tetraazaoctadecanes. Calculations employing a SYBYL modeling program revealed that the distance between terminal nitrogens ranges between 12.62 and 19.61 A. The tetraamines are constructed such that within families cyclics and acyclics have similar lengths but different nitrogen pKa's and thus different protonation, or charge, states at physiological pH. The pKa values for all nitrogens of each molecule and its protonation state at physiological pH are described. The modifications at the terminal nitrogens include introduction of ethyl and beta,beta,beta-trifluoroethyl groups and incorporation into piperidinyl or pyridyl systems. The studies clearly indicate that polyamine length, charge, and terminal nitrogen substitution have a significant effect on how the tetraamine regulates MK-801 binding to the NMDA receptor. Thus a structure-activity basis set on which future design of MK-801 agonists and antagonists can be based is now available.     

一种碳－碳复合材料长寿命防氧化涂层的失效机制

用液相法联合ＣＶＤ法和硅化法制备了一种碳－碳复合材料复合梯度涂层，在此基础上对这种涂层在氧化过程中的失效机制进行了研究．结果表明：氧化层与液相层界面反应生成的气相产物是涂层失效的根本原因界面上气泡的不均匀形核、长大和破裂导致涂层表面出现孔洞．孔洞处气泡优先形核、长大和破裂并发展成为缺陷而使涂层失效     

ANALYSIS ON ROOM TEMPERATURE TENSILE STRENGTH OF δ-Al_2O_3, FIBER / Al-12Si COMPOSITE

对δ－Ａｌ２Ｏ３纤维／Ａｌ－１２Ｓｉ复合材料室温拉伸强度的分析表明，在实验条件下该复合材料存在δ－Ａｌ２Ｏ３纤维的最小体积分数Ｖｍｉｎ和临界体积分数Ｖｃｒｉｔ，并求出其基体强度δｍ和室温强度σｃ－δ－Ａｌ２Ｏ３纤维体积分数Ｖｆ直线方程及纤维的临界长度ｌｃ和复合材料的剪切应力τＰ确定复合材料的ＲＯＭ预测曲线，应首先判断σｍ是否等于未增强合金的强度σｕｍ才能得出正确的结论。     

90°分束偏光镜光强分束比研究

给出了90°分束偏光镜的e,o光光强分束比的计算公式,以及光强分束比随光波长的变化曲线;在6328Å测得的光强分束比与计算值是一致的。