Hg1—xCdxTe的扫描光致发光研究

用傅里叶变换红外扫找光致发光方法研究了Ｈｇ１－ｘＣｄｘＴｅ体单晶样品。该方法可直接得到ＨｇＣｄＴｅ晶片组分的二维平面分布，并可得到辐射复合在复合机制中所占比重的平面分布，以及晶体中非平衡流子寿命的分布。     

傅里叶红外显微光谱技术测量HgCdTe晶片组分分布与截止波长分布

运用傅里叶红外显生光谱技术测量了ＨｇＣｄＴｅ晶片上透射光谱分析，并通过编程处理，得到ＨｇＣｄＴｅ晶片组分分布和截止波长分布图。     

碲镉汞合金组分分布的描述方法

介绍了一种利用ＥＤＸ和自动数据处理程序相结合。用于ＨｇＣｄＴｅ晶体组合分布研究的描述方法。实际使用结果表明，该方法满足ＨｇＣｄＴｅ晶体组分分布研究的要求，具有快速直观的特点，对指导工艺调整有重要意义，该法可用于其他半导体材料的成分分析。     

CdTe-HgCdTe界面的电导机制

本文研究了ＣｄＴｅ和ｎ型、ｐ型Ｈｇ０．５３Ｃｄ０．４７Ｔｅ界面的电学特性．ｎ型ＨｇＣｄＴｅＭＩＳ结构强反型区开始处的电导峰是表面处禁带态辅助的间接隧穿引起的；而ｐ型ＨｇＣｄＴｅＭＩＳ结构的强反型区电导出现两个振荡峰，是体陷阱辅助的价带电子到表面反型层二维子带的隧穿引起的，而耗尽区的电导峰则为界面态产生复合．指出ｐ型和ｎ型ＨｇＣｄＴｅＭＩＳ结构隧穿电导的差别是：ｐ型ＨｇＣｄＴｅＭＩＳ结构隧穿对表面处的禁带态不敏感．并用电导法研究ＣｄＴｅ／ＨｇＣｄＴｅ界面态在禁带中的分布，求得了界面态的时间常数和俘获截面     

180元HgCdTe线列器件的冷屏效应与背景限性能

从理论上分析了１８０元ＨｇＣｄＴｅ线列器件的冷屏效应，计算了１８０元ＨｇＣｄＴｅ线列探测器每个光敏元所对应的平面视场角（ＦＯＶ）及其在３００Ｋ背景辐射下的背景限探测率，并将实际的１８０元ＨｇＣｄＴｅ线列探测器件每个光敏元的性能同理论进行了比较，结果表明１８０元长波红外ＨｇＣｄＴｅ线列探测器的性能已经接近室温背景的理论极限．     

CdTe钝化的HgCdTe非平衡载流子表面复合速度的实验研究

利用Ａｒ＾＋束央求宙积技术在ＧｇＣｄＴｅ表面实现了低温ＣｄＴｅ介质薄膜的低温生长。在用－ＨｇＣｄＴｅ晶片表面分别用ＣｄＴｅ介质膜、ＨｇＣｄＴｅ自身阳极氧化膜进行表面钝化。利用光电导衰退测量技术测量了两种不同表面钝化的薄ＨｇＣｄＴｅ晶片的非平衡载流子（少数载流子）寿命,并通过光电导衰减信号波形的拟合,得到两种不同表面钝化的ＨｇＣｄＴｅ表面复合速度。实验结果表明,获得的ＣｄＴｅ／ＨｇＣｄＴｅ界面质量已     

碲镉汞薄膜材料

研制ＨｇＣｄＴｅ焦平面器件是当前实现长波红外焦平面器件的主要途径。红外焦平面器件要求大面积、均匀性好和高质量的ＨｇＣｄＴｅ材料。用ＬＰＥ、ＭＯＣＶＤ和ＭＢＥ外延生长的ＨｇＣｄＴｅ薄膜材料可满足焦平面器件对材料的要求。ＬＰＥ是目前研制ＨｇＣｄＴｅ光伏列阵主要材料，用双层掺杂生长的ｐ－ｎ异质结得到当前最高的Ｒ＿０Ａ值。ＭＯＣＶＤ和ＭＢＥ生长的ＨｇＣｄＴｅ外延膜近期有了较大的进展，除了在硅衬底上ＭＢＥ生长ＨｇＣｄＴｅ仍在研究之外，其它已趋向成熟并开始转向工业生产。为了研制高质量的ＨｇＣｄＴｅ外延膜，高质量的衬底材料与建立薄膜均匀性的检测工艺是十分必要的。     

（Hg，Cd）Te薄腰的LPE生长条件与纵向组分分布

根据热力学理论推导出（Ｈｇ，Ｃｄ）Ｔｅ液相外延生长过程中有效分凝系数的表达式并与实验结果进行比较，由此分析了Ｈｇ压、溶液组成、降温速度及过冷度等对（Ｈｇ，Ｃｄ）Ｔｅ液相外延薄膜纵向组分分布的影响．     

（Hg,Cd）Te薄膜的LPE生长条件与纵向组分分布

根据热力学理论推导出（Ｈｇ，Ｃｄ）Ｔｅ液相色延生长过程中有效分凝系数的表达式并与实验结果进行比较，由此分析了Ｈｇ压、溶液组成、降温国速度及过度等对（Ｈｇ，Ｃｄ）液相外延薄膜纵向组分分布的影响。     

用室温红外透射谱研究Hg_（1－x）Cd_xTe外延薄膜的组份分布

根据Ｈｇ１－ｘＣｄｘＴｅ本征吸收系数的经验公式及Ｈｏｕｇｅｎ模型，建立了一种用室温红外透射谱研究Ｈｇ１－ｘＣｄｘＴｅ外延薄膜组份均匀性的方法，用这种方法检测了ＬＰＥ、ＭＢＥ、ＭＯＣＶＤ薄膜的组份分布，并与二次离子质谱（ＳＩＭＳ）测量结果进行了比较     

Lifetime distribution based degradation analysis

The methods commonly used for degradation analysis deduce the lifetime distribution of a product from the distribution of the random parameters in the degradation path model for the product. This approach requires a functional form of the joint distribution of the random parameters, which poses certain practical difficulties. In this paper, we propose an alternative approach which makes inference directly on the lifetime distribution itself. In the proposed approach, degradation data are first used to derive predictive intervals of individual lifetimes. Then an imputation algorithm is invoked to obtain the estimate of the lifetime distribution. The approach has the following advantages: 1) the adequacy of the assumption on the lifetime distribution can be easily examined, 2) the estimated lifetime distribution has a closed form, and 3) the procedure can be more easily implemented. A simulation study is reported to demonstrate the efficiency of the proposed approach. The approach is applied to two real degradation data sets, and compared with Lu-Meeker's two stage method in the applications.     

威布尔分布下VFD恒定应力加速寿命试验与统计分析

为了精确地估计真空荧光显示器(VFD)的可靠性寿命,节省试验测试时间,通过建立加速寿命试验模型开展了4组恒定应力加速寿命试验,采用威布尔函数描述VFD寿命分布,利用最小二乘法(LSM)估计威布尔参数,完成了试验数据的统计分析,并自行开发了寿命预测软件,确定了加速寿命方程,实现了VFD的寿命估计。数值结果表明,试验设计方案是正确可行的,VFD的寿命服从威布尔分布,其加速模型符合线性阿伦尼斯方程,每个加速应力水平下VFD的失效机理不变,精确计算出的VFD寿命对其生产厂商和技术人员具有重要的指导意义。     

Expert judgment in maintenance optimization

A comprehensive method for the use of expert opinion for obtaining lifetime distributions required for maintenance optimization is proposed. The method includes procedures for the elicitation of discretized lifetime distributions from several experts, the combination of the elicited expert opinion into a consensus distribution, and the updating of the consensus distribution with failure and maintenance data. The development of the method was prompted by the lack of statistical training of the experts and the high demands on their time. The use of a discretized life distribution provides more flexibility, is more comprehendible by the experts in the elicitation stage, and greatly reduces the computation in the combination and updating stages. The methodology is Bayes, using the Dirichlet distribution as the prior distribution for the elicited discrete lifetime distribution. Methods are described for incorporating information concerning the expertise of the experts into the analysis     

Charge-carrier lifetime in Hg1−x CdxTe (x=0.22) structures grown by molecular-beam epitaxy

Measurements of the charge carrier lifetime in epitaxial structures based on narrow-gap Hg_1−x Cd_xTe (x=0.22), grown by molecular-beam epitaxy with pulsed excitation using radiation at different wavelengths, are reported. It is shown that in p-type epitaxial films the lifetime is determined by the Auger recombination mechanism at temperatures corresponding to the impurity conductivity, and for n-type epitaxial films recombination via local centers is characteristic. Fiz. Tekh. Poluprovodn. 31, 774–776 (July 1997)     

基于能量预测的无线传感器网络节点覆盖调度算法

针对无线传感器网络中存在的热区问题,采用非均匀部署方案,并在此基础上提出基于能量预测的无线传感器网络节点覆盖调度算法。并对算法进行了仿真实验和性能分析。结果表明该算法可以延长的网络生命周期并在较长的时间里保持较高的网络覆盖率,能够达到网络内大多数节点能耗均衡的设计目标。     

Coverage and Lifetime Optimization of Wireless Sensor Networks with Gaussian Distribution

A wireless sensor network (WSN) has to maintain a desirable sensing coverage and periodically report sensed data to the administrative center (i.e., base station) and the reporting period may range from months to years. Coverage and lifetime are two paramount problems in a WSN due to constraint of associated battery power. All previous theoretical analysis on the coverage and lifetime is primarily focused on the random uniform distribution of sensors or some specific network scenarios (e.g., a controllable WSN). In this paper, we provide an analytical framework for the coverage and lifetime of a WSN that follows a two-dimensional Gaussian distribution. We also study the coverage and lifetime when the dimensions of Gaussian dispersion (i.e., x, y) admit different Gaussian parameters (i.e., standard deviation, $sigma_x neqsigma_y$). We identify intrinsic properties of coverage/lifetime in terms of Gaussian distribution parameters, which is a fundamental issue in designing a WSN. Following the results obtained, we further determine the sensor deployment strategies for a WSN that could satisfy a predefined coverage and lifetime. Two deployment algorithms are developed based on using our analytical models and are shown to effectively increase the WSN lifetime.     

Lifetime Estimation Using Only Failure Information From Warranty Database

Knowledge about product lifetime obtained from actual usage (field data) is of great importance to manufacturers who want to get information about the true reliability of their products. Warranty data are frequently used to estimate reliability characteristics because such databases are automatically generated and updated at no additional cost from repair claims during warranty coverage. For engineering purposes, usage time (e.g., mileage) is more relevant, and lifetime parameters measured in usage time is an integral part of reliability analysis using warranty data. Usually, warranty data consist of only failure information. Censored data (e.g., mileage of non-failure automobiles) are not obtainable, of which usage time distributions are different from those of failed ones. Effective usage-based estimation thus requires supplementary information about usage accumulation for non-failure units such as follow-up studies, or a usage time distribution which includes both failure, and non-failure products. However, sometimes usage-based data for non-failed units are expensive and difficult to obtain. Thus, the unavailability of the usage time of censored units makes it difficult to estimate the usage-based lifetime distribution of products. This paper deals with that problem, and discusses how to estimate the lifetime distribution using warranty data which consist of only failure information. The practical consequence of this finding is that supplemental information is not needed to obtain correct estimates of the lifetime parameters.      

Energy Balanced Model for Lifetime Maximization in Randomly Distributed Wireless Sensor Networks

In this paper, an energy balanced model (EBM) for lifetime maximization for a randomly distributed sensor network is proposed. The lifetime of a sensor network depends on the rate of energy depletion caused by multiple factors, such as load imbalance, sensor deployment distribution, scheduling, transmission power control, and routing. Therefore, in this work, we have developed a mathematical model for analysis of load imbalance under uniform and accumulated data flow. Based on this analysis, we developed a model to rationalize energy distribution among the sensors for enhancing the lifetime of the network. To realize the proposed EBM, three algorithms—annulus formation, connectivity ensured routing and coverage preserved scheduling have been proposed. The proposed model has been simulated in ns-2 and results are compared with Energy-Balanced Transmission Policy and Energy Balancing and unequal Clustering Algorithm. Lifetime has been measured in terms of the time duration for which the network provides satisfactory level of coverage and data delivery ratio. EBM outperform both the existing models. In our model the variance of residual energy distribution among the sensors is lower than other two models. This validated the essence of energy rationalization hypothesized by our model.     

Reliability bounds for some static system models using lifetime data on their components

It has become increasingly difficult to obtain a sampling distribution of the reliability function of a system. Therefore, reliability bounds have been studied to facilitate the analysis of reliability characteristics. The bounds for the reliability of the system depend on the mean and variance of the lifetimes recorded on the system. However, in the early stages of design, the lifetime data on a system may either be costly or non-existent. Thus, by using lifetime data on the components of the system, the present study deals with the analysis of reliability bounds for some static system models.     

荧光寿命分析法鉴别机油品种特征信息提取

由于机油的品种鉴别在环境监测、事故认定等领域有着重要的作用,结合非线性最小二乘法的荧光寿命衰减曲线提取技术,能解决不同机油混合后的分类识别问题。研究通过激光诱导荧光雷达系统,利用时间分辨荧光实验,采用非线性最小二乘法将荧光寿命衰减曲线按照不同指数拟合,从相关指数及残差分布确定最佳拟合曲线。实验结果表明,三种不同机油产品的荧光寿命衰减曲线按照不同指数衰减其拟合效果不同,选取各自最佳拟合曲线,按照合成规律可以拟合出不同机油的荧光平均寿命参数,通过误差分析可信赖程度在95%以上。当以所有激发区域内像素点的平均荧光寿命为中心,利用2倍标准差作为置信限,统计其中两种不同机油激发区域中像素点荧光寿命值落入各自置信区间内的概率,二者的概率分别为87%和68%。通过三种不同油品的对比试验,验证了利用荧光寿命分析法实现不同机油产品油种识别的可能性,并可通过荧光寿命成像判断不同油种的空间分布信息。荧光寿命分析法为机油产品油种鉴别、成分分析及检测空间分布提供了一种新途径。