高性能ZnO纳米块体材料的制备及其拉曼光谱学特征

利用六面顶高压设备制备了高密度、低脆性、纳米级的ZnO块体材料，用MDI/JADE5 X射线衍射仪(Cu靶)和XL30S-FEG场发射扫描电子显微镜对高压样品的相组成、晶粒尺寸及微观形貌进行了表征.利用E55+FRA106/5傅里叶变换激光拉曼光谱仪通过ZnO块体样品位于50—500cm^-1之内的拉曼光谱, 研究了极性半导体纳米材料的拉曼光谱学特征.发现在极性半导体ZnO纳米块体材料中，没有出现明显的尺寸限制效应. 关键词： ZnO纳米块体 拉曼光谱 尺寸限制效应     

Element Importance and System Failure Frequency of a 2-State System

This paper redefines three measures of element s-importance for 2-state systems regardless of s-coherence, presents the calculation methods of these measures, and gives a new method to calculate the system time-specific failure and recovery frequencies. A poor point in the literature in extending methods for evaluating the s-importance of elements of s-coherent system to non-coherent system is pointed out. An example illustrates these definitions and calculation methods.     

拟南芥胚的不同区域对MeV离子辐照的响应

利用不同能量的质子在大气环境中辐照拟南芥的含水种子，能量从1.1MeV到6.5MeV.根据模拟计算结果，相应能量的离子对种子的损伤区域分别为胚的浅层、胚的一半和整个胚.本实验中，具有较高能量的质子可以完全均匀地作用于拟南芥生长、发育及遗传密切相关的胚茎端分生组织，而能量较低的质子则不能直接作用于茎端分生组织.实验所用质子注量范围为4×10⁹ions/cm²—1×10¹⁴ions/cm².实验结果显示，虽然拟南芥种子的发芽率和幼苗存活率随离子注量增加都呈现下降的趋势，但对应于不同的胚损伤区域，即在不同的入射质子能量条件下，注量曲线具有各自的特征.实验结果显示，拟南芥种子中除了胚茎端分生组织作为对离子辐照敏感的辐射主靶外，茎端分生组织之外的胚区域可能作为离子辐射次靶，影响到最终的辐射生物学效应. 关键词： 离子辐照 拟南芥 胚区域 生物效应     

生长温度对磁控溅射ZnO薄膜的结晶特性和光学性能的影响

采用反应射频磁控溅射方法，在Si (100) 基片上制备了具有高c轴择优取向的ZnO薄膜.利用 原子力显微镜、透射电子显微镜、X射线衍射分析、拉曼光谱等表征技术，研究了沉积温度 对ZnO薄膜的表面形貌、晶粒尺度、应力状态等结晶性能的影响；通过沉积温度对透射光谱 和光致荧光光谱的影响，探讨了ZnO薄膜的结晶特性与光学性能之间的关系.研究结果显示， 在室温至500℃的范围内，ZnO薄膜的晶粒尺寸随沉积温度的增加而增加，在沉积温度为500 ℃时达到最大；当沉积温度为750℃时，ZnO薄膜的晶粒尺度有所减小；在室温至750℃的范 围内，薄膜中ZnO晶粒与Si基体之间均存在着相对固定的外延关系；在沉积温度低于500℃时 ，制备的ZnO薄膜处于压应变状态，而750℃时沉积的薄膜表现为张应变状态.沉积温度的不 同导致ZnO薄膜的折射率、消光系数、光学禁带宽度以及光致荧光特性的变化，沉积温度对 紫外光致荧光特性起着决定性的作用.此外，探讨了影响薄膜近紫外光致荧光发射的可能因 素. 关键词： ZnO薄膜 表面形貌 微观结构 光学常数     

专用集成电路CAT技术的进展

本文简单地回顾了提高VLSI测试效率所采用的一些手段,讨论了在ASIC测试问题研究中出现的一些新观点、新方法、新动向,以及所取得的成果。在此基础上,文章阐明了ASIC测试技术的发展方向,并着重论述了可望在未来得到发展的,针对ASIC的功能测试方法。     

Method of selecting the regularisation parameter for microwaveimaging

The Tikhonov regularisation technique is widely used in the solution of inverse scattering problems. One of the difficulties in applying this technique is the proper selection of the associated regularisation parameter. Based on a stochastic model of the reconstruction process, a simple method is presented for selecting this parameter for an efficient implementation of various microwave imaging methods     

(NH4)2MoS4在活性炭上浸渍过程的研究:Ⅱ.干燥机理及模型

（ＮＨ＿４）＿２ＭｏＳ＿４在活性炭上浸渍过程的研究Ⅱ．干燥机理及模型秦慧芳，张成芳，陆岗，俞丰，朱子彬（华东理工大学无机化工研究所，上海２００２３７）２３７）关键词硫代钼酸铵，活性炭，干燥，钼分布，干燥模型负载型催化剂的活性组分在载体上的分布，受浸渍...     

A Survey of E-Commerce Security

E-commerce is a very active field of Internet research. A very important aspect of e-commerce is its security. Because of the variety of e-commerce applications, many security policies, protocols and techniques are involved in the deployment of the security. The related standards and protocols of e-commerce are studied in this paper. The general model of e-commerce security is set forth. In this model, two most important e-commerce protocols including secure sockets layer (SSL) and secure electronic transaction (SET) are analyzed. The open problems and new trends of e-commerce security are presented.     

An investigation of bulk recycling planning for an electronics recycling facility receiving industrial returns versus residential returns

Since most end-of-life electronics equipment contain hazardous materials such as lead solder alloys or lead-impregnated glass, it is important to divert them from landfills. For end-of-life products that are not repairable and do not contain reusable parts, bulk recycling is an alternative to recover base materials. In this paper, we contrast production and recycling planning and distribution decisions, activities, and costs. We reveal that while a traditional production facility connects suppliers and customers, a recycling facility connects both "input" and "output" customers. As a result, decisions in short-term bulk recycling planning include what products to accept, what products to process and reprocess, and what products to carry in inventory. Many recyclers set prices to receive "input" based on experience. For various prices to receive "input", we use a new analytical model to investigate the sensitivity of the short-term bulk recycling planning decisions in products from two different sources: industrial returns versus residential returns. The results of the case study show that different decisions are recommended for the industrial returns versus the residential returns when the total quantity of the incoming products is equal.     

光电光谱法分析钢中钙

本文研究了用光电光谱法测定钢中钙的方法 ,确定了最佳分析条件 ,分析了共存元素的干扰情况。用本方法测定钢中钙 ,具有良好的准确度和精密度 ,结果令人满意。