Undoped semi-insulating indium phosphide (InP) and its applications

During the past several years, the research and development of InP material has made great progress due to serving as the substrate for most optoelectronic devices operating at the communications wavelength of 1.31 and 1.55 μm. At present, InP has become an important semiconductor material together with Si and GaAs. When compared to GaAs, InP has higher electron velocity, higher radiation hardness and better heat-conducting property. The advantage of InP crystal material allows higher frequency operation and lower power requirements. Therefore, InP is widely being used for the manufacture of microwave devices, high-frequency devices and optoelectronic integrated circuits (OEICs) which are indispensable for wireless technology, satellite communications^[1—3]. Although n-type and p-type InP can meet actual needs, semi-insulating InP substrates remain to be improved due to their poor uniformity and consistency. For this reason, several possible approaches have been reported to the preparation of SI InP by wafer annealing under different conditions^[4—9].     

Expression of thymosin-β4, RACK1 and HMGB in adult amphioxus: implication for the evolutionary conservation of organ related functional molecules

Vertebrate thymosin-β4, RACK1 and HMGB are important molecules functioning in embryonic development and adult life. Here we report the expression patterns of amphioxus thymosin-β4, RACK1 and HMGB genes in tissues of adult amphioxus as revealed by RT-PCR and in situ hybridization. These three genes are all strongly expressed in the central nervous system and ovary, but differently expressed in other tissues including gut, testis, wheel organ, gill and endostyle.     

Efficient Fault Tree Analysis of Complex Fault Tolerant Multiple-Phased Systems

Fault tolerant multiple phased systems (FTMPS), i.e., systems whose critical components are independently replicated and whose operational life can be partitioned in a set of disjoint periods, are called "phases". Because of their deployment in critical applications, their reliability analysis is a task of primary relevance to validate the designs. Fault tree analysis based on binary decision diagram (BDD) is one of the most commonly used techniques for FTMPS reliability analysis. To utilize the technique the fault tree structure of FTMPS needs to be converted into the corresponding BDD format. Our research work shows that the system BDD generation algorithms presented in the literature are too inefficient to be used for industrial complex FTPMS because of the problems, such as variable ordering and combination of large BDDs. This paper presents a more efficient approach consisting of a flatting pre-processing technique, a proved efficient ordering heuristic and a bottom-up generation algorithm. The approach tries to combine share-variable BDDs by complex combination operation firstly and then combine no-share-variable BDDs using simple combination operation, thus to alvoid the intensive computations caused by large BDD combination operations. An example FTMPS is analyzed to illustrate the advantages of our approach.     

泥岩遇水软化微观机理研究

通过扫描电镜与X射线衍射仪对不含蒙脱石的华北中生代煤系地层泥岩的微观结构与物质组成进行分析，研究了该泥岩遇水软化过程中微观结构随时间变化的动态特征．研究表明：泥岩中的矿物颗粒在水的作用下，颗粒间的连结将逐渐破坏，使水分进入层状颗粒之间，从而在岩石内部产生不均匀内应力以及大量的微孔隙．这些微孔隙的出现及其吸附效应的影响，进一步破坏了岩石的内部结构体系，使泥岩在宏观上产生软化崩解的现象．可见，泥岩内部结构体系的特点是其软化崩解的真正原因，而是否含有蒙脱石并非泥岩软化崩解的决定性因素．     

基于MATLAB频分多址接入模型的仿真研究

介绍了频分多址模型,对模型进行了理论分析,采用Matlab编程模拟了其通信过程,并对实验结果进行了分析,实验表明该方法实用可行。     

添加Ti0.9Zr0.1Mn1.5复合球磨对Ti9.6V86.4Fe4 合金储氢性能的影响

系统研究了Ti9.6V86.4Fe4储氢合金中掺入10%（质量分数）的Ti0.9Zr0.1Mn1.5进行复合球磨对其相结构及储氢性能的影响.X射线衍射分析表明,Ti9.6V86.4Fe4铸态合金具有单一的体心立方（BCC）结构固溶体相,当添加10%的Ti0.9Zr0.1Mn1.5复合球磨后,复合物由BCC主相和C14型Laves第2相组成.扫描电子显微镜及X射线能量色散谱仪分析表明,Ti9.6V86.4Fe4合金粉颗粒表面包覆了一层Ti0.9Zr0.1Mn1.5微粒.储氢性能测试表明,Ti9.6V86.4Fe4中掺入10%的Ti0.9Zr0.1Mn1.5复合球磨后,虽然室温最大吸氢量（质量分数）从3.86%略微降低至3.61%,但其有效储氢量（质量分数）由2.01%提高到2.11%,活化性能和P-C-T曲线平台特性都得到了明显改善.     

基于贝叶斯公式的信息反馈机制

提出了一种基于贝叶斯公式的信息反馈模型BIF.当系统拒绝用户对资源的访问时,BIF通过计算在当前的条件下改变某些访问条件的可能性,把用户的访问条件的替代方案限制到一个小而有用的集合,系统将具有最大可能性的选项反馈给用户.用户根据系统的反馈改变访问条件从而成功访问资源.BIF引入附加策略来保护敏感策略,在此过程中不会泄漏任何危及到系统安全和机密性的信息.实验证明,BIF模型在保护了系统敏感信息的同时,也提高了系统的可用性及访问成功的几率.     

气隙式膜蒸馏法分离浓缩透明质酸水溶液的研究

介绍了应用气隙式膜蒸馏分离技术对透明质酸热敏性水溶液的浓缩分离情况. 结果表明, 使用膜孔径为0.2μm的聚四氟乙烯微孔疏水膜可使原料液的浓度提高1.6倍以上, 透明质酸截留率为80%以上. 探讨了循环时间、平均温差、热侧温度等条件对分离效果的影响, 并讨论了膜蒸馏过程热效率的变化规律.     

加强公路中小桥梁养护的建议

随着交通量的增加,过去修建的公路旧桥陈旧老化,破坏严重,难以适应发展的要求,文章论述了对旧桥加强养护和加固的10点建议.