压电量测系统漏电影响分析

本文通过对压电量测系统等效电路图的逐步简化,得出矩形脉冲信号的漏电方程;并对系统在各种情况下的时间常数,漏电相对误差进行了计算,最后就系统在校准和现场测试中经常碰到的几种情况,进行了定量估算,从而解决了压电量测系统在使用中的一些具体问题。     

岩土体斜(边)坡滑坡发生的机理

根据滑坡发生的初始条件、滑坡成因及方式表象,对常见的蠕变倾覆滑坡、卸荷滑坡、震动液化平推滑坡、潜蚀塌陷滑坡、溶蚀下陷滑坡、孔隙水压浮动滑坡和人工切蚀或冲(浪)蚀—加载滑坡等机理进行了分析.     

1/3码的动态CMOS全自检电路的设计

自检测电路设计方法有多种多样,本文中介绍了TSC电路的概念,并采用1/3码的动态CMOS设计TSC电路,通过在Cadence环境下仿真,仿真结果表明本设计可行。     

八种新功能晶体的比热及其与相变掺杂物关系的实验研究

本文对八种新型功能晶体Ｌｉ２Ｂ４Ｏ７、Ｂｉ１２ＴｉＯ２０、Ｂｉ１２ＧｅＯ２０、Ｂｉ１２ＧｅＯ２０、Ｂｉ４Ｇｅ３Ｏ１２、Ｓｒ１－ｘＢａｘＮｂ２Ｏ６（ｘ＝０．３３，０．４８）、ＬｉＴａＯ３等在１３０～９７３Ｋ范围内的比热行为及其与相变、组分之间的关系进行了实验研究，给出了比热的多项式拟合方程，并与用纽曼－卡普定律及用Ｗｉｋｅｌｍａｎｎ经验方程的比热计算值作了对比，为晶体比热的估算提供了依据和方法。     

电子束、离子束与蓝宝石相互作用的研究

研究了电子束、离子束作用于Al2O3表面时成分的变化，表明无论电子束或离子束都能使Al2O3发生分解，产生导电的元素Al。实验在PHI610·SAM上进行，电子束轰击下（3keV，O．5μA，入射角60°）10s就有元素Al分解出来，2min以后就达到饱和，分解析出量随时间成a（1－e－bt）的关系。离子束轰击下同样发生元素Al的分解，但当Ei＞3keV时，由于剥离速率加大，溅射5min时表面Al峰反而比1min时要弱。这时表面Al含量处于分解析出与溅射剥离的动态平衡中。实验还发现了Al2O3的解析与表面成分有关（如碳的含量）。最后讨论电子束与离子束的解析机理。     

Residual stresses and transformation toughening in MoSi2 composites reinforced with partially stabilized zirconia

The results of study of the effects of yttria stabilization (0–6 mol.%) on the room-temperature fracture behavior and toughening mechanisms in zirconia-reinforced MoSi₂ are presented in this paper. Transformation toughening is shown to occur only in composites reinforced with zirconia particles stabilized with 2 mol.% yttria. However, the fracture toughness levels are comparable in the other composites with yttria levels between 0 and 6 mol.%. Toughening in the other composites is attributed to the combined effects of residual stress, microcrack shielding/anti-shielding and/or crack deflection. A rigorous micromechanics-based model is presented for the estimation of residual stress levels in brittle materials reinforced with phases that can transform during cooling or under stress. The model is applied successfully to the rationalization of the observed fracture and toughening phenomena.     

波导短程透镜球差特性分析及其焦距精确测量方法的研究

本文研究短程透镜的焦点位于端面外的球差特性。对焦点位于波导外部（包括端面）的情况给出了一种精确测量焦距新方法，采用这种方法简单易行，测量精度取决于读数显微镜的读数精度（０．０１ｍｍ）。     

北淮阳金寨-霍山地区火山机构遥感地质解译研究

利用不同时期成像的航卫片资料，圈定和寻找北淮阳金寨－霍山地区火山机构，结合地面验证，研究火山活动的空间展布规律，以及火山机构的成矿控矿作用。     

粉尘薄膜爆轰

与普通爆轰不同，粉尘薄膜爆轰波前氧化剂与燃料处于分离状态．由于激波作用下壁面燃料的注入才于壁面附近形成燃烧的粉尘云，燃烧释放的热使激波自持形成粉尘薄膜爆轰。本文在长2、8m，横截面20mm×20mm的方型水平激波管中对此类爆轰进行了实验研究．并根据作者建立的模型对其二维结构进行了数值模拟。     

Selective phosphorylation of adult tau isoforms in mature hippocampal neurons exposed to fibrillar A beta

How senile plaques and neurofibrillary tangles are linked represents a major gap in our understanding of the pathophysiology of Alzheimer's disease. We characterized a hippocampal neuronal culture system in which tau undergoes maturation in vivo; rat neurons maintained in culture for more than 3 weeks replicated the splicing and phosphorylation changes that tau undergoes upon maturation in situ. Using this model system, we induced an Alzheimer-like neuritic dystrophy following the application of fibrillar beta-amyloid. The dystrophy consisted of focal distortions and swellings within the neurites and an altered phosphorylation of the adult tau isoforms. Fibrillar beta-amyloid induced the concomitant activation of MAP kinase and GSK3 beta. The aberrant activation of several signaling pathways may lead to the abnormal phosphorylation of tau and neuritic degeneration.