Study on the negative bias temperature instability effect under dynamic stress

This paper studies negative bias temperature instability (NBTI) under alternant and alternating current (AC) stress. Under alternant stress, the degradation smaller than that of single negative stress is obtained. The smaller degradation is resulted from the recovery of positive stress. There are two reasons for the recovery. One is the passivation of H dangling bonds, and another is the detrapping of charges trapped in the oxide. Under different frequencies of AC stress, the parameters all show regular degradation, and also smaller than that of the direct current stress. The higher the frequency is, the smaller the degradation becomes. As the negative stress time is too small under higher frequency, the deeper defects are hard to be filled in. Therefore, the detrapping of oxide charges is easy to occur under positive bias and the degradation is smaller with higher frequency.     

含部分晶须的钛酸锂的制备及其性能表征

L i4T i5O12是一种循环性能好、有很好的充放电平台、理论比容量较大、不与电解液反应的新型负极材料,研究探索以偏钛酸和碳酸锂为主要原料制备含部分晶须的尖晶石型晶型L i4T i5O12的一种方法。通过此工艺在1 000℃煅烧8 h后在样品中约20%的晶须出现,晶须的直径≤0.5μm,晶须的长度约为7μm。     

Analytical layer‐element method for non‐axisymmetric consolidation of multilayered soils

A numerically efficient and stable method is developed to analyze Biot's consolidation of multilayered soils subjected to non‐axisymmetric loading in arbitrary depth. By the application of a Laplace–Hankel transform and a Fourier expansion, the governing equations are solved analytically. Then, the analytical layer‐element (i.e. a symmetric stiffness matrix) describing the relationship between generalized displacements and stresses of a layer is exactly derived in the transformed domain. Considering the continuity conditions between adjacent layers, the global stiffness matrix of multilayered soils is obtained by assembling the inter‐related layer‐elements. Once the solution in the Laplace–Hankel transformed domain that satisfies the boundary conditions has been obtained, the actual solution can be derived by the inversion of the Laplace–Hankel transform. Finally, numerical examples are presented to verify the theory and to study the influence of the layered soil properties and time history on the consolidation behavior. Copyright © 2011 John Wiley & Sons, Ltd.     

区域次生地球化学负异常模型及其意义

原生地球化学负异常的研究已经引起重视,特别是前苏联的化探工作者还总结出利用地球化学原生负异常对热液矿床进行普查和评价的准则.但是,由于缺乏可供对比的划分负异常的适当方法,使得对负异常的研究不能系统化,研究结果也不能互相对比,尤其是对于区域水系沉积物测量中发现的负异常研究很少.本文通过对几个地区衬值负异常的分析,系统地探讨了区域性负异常的分布特征、负异常与正异常的关系、负异常的地质意义和找矿信息等.总结出单元素和多元素区域负异常的分布模型.建立了AU和Cu矿床的区域正负、异常模型.提出了地球化学异常是由正异常和负异常组成的.     

EKMAN PUMPING OVER MOUNTAINS

The analytical results of the previous paper(Wu,1989)are used to study the properties of vertical veloc-ity distribution at the top of the boundary layer.The relative position of a jet like geostrophic flow and el-lipse-shaped orography will affect the characteristic feature of vertical motion at the top of the boundary layerwhen the contributions of friction and orography are taken into consideration simultaneously.     

金矿床石英中负价氮的发现及赋存状态探讨

利用ｘ光电子能谱测试，发现金矿床石英中有负价氮的存在。这种氮的结合能为３９８ｅＶ士，该结合能氮的化合物有多种，氦均为负价态，其中有Ｓｉ＿３Ｎ＿４Ｓｉ的ｘ光电子能谱有二个谱峰值：１０３．４ｅＶ和１０１．９ｅＶ，前者为ｓｉＯ＿２的结合能，后者为Ｓｉ＿３Ｎ＿４的结合能。Ｎ和Ｓｉ的结合能均表明石英中有Ｓｉ＿３Ｎ＿４为负三价态。石英中负价Ｎ可能为替代氧的类质同象成分。     

放射性测量技术在油气勘查中的应用

本文介绍的油气勘查中的放射性测量，是一种油气普查新方法。它是利用油田上出现的负异常（或叫偏低场），反映了油气田的大体轮廓的基本原理进行的。前人及作者都取得了一定的工作成果。虽然取得了初步效果，但对机理等问题仍需进一步研究和完善。     

冬季青藏高原对东移大槽动力影响的研究：Ⅲ.模拟试验结果的分析

具体分析了本文Ⅱ的模拟试验结果。结果表明，该试验较清楚地再现了青藏高原地形对西风气流的影响，也显示了不同地形、急流的有无、强度和位置以及初始槽强度和基本气流斜压性的强度对东移槽的影响。这些结果有的清楚地再现了过去熟知的或还不很清楚的地形影响事实，有的可为东移槽的预报提供着眼点。     

西安地区地下水位下降及其环境负效应

本文通过西安地区多年地下水位动态资料,分析区域潜水及城郊自备井集中开采区承压水水位持续下降状况,阐述了地下水位持续下降对水环境、农业环境及城市地质环境所产生的负效应。