Juxtaposed regions of extensive and minimal linkage disequilibrium in human Xq25 and Xq28

Linkage disequilibrium (LD), or the non-random association of alleles, is poorly understood in the human genome. Population genetic theory suggests that LD is determined by the age of the markers, population history, recombination rate, selection and genetic drift. Despite the uncertainties in determining the relative contributions of these factors, some groups have argued that LD is a simple function of distance between markers. Disease-gene mapping studies and a simulation study gave differing predictions on the degree of LD in isolated and general populations. In view of the discrepancies between theory and experimental observations, we constructed a high-density SNP map of the Xq25-Xq28 region and analysed the male genotypes and haplotypes across this region for LD in three populations. The populations included an outbred European sample (CEPH males) and isolated population samples from Finland and Sardinia. We found two extended regions of strong LD bracketed by regions with no evidence for LD in all three samples. Haplotype analysis showed a paucity of haplotypes in regions of strong LD. Our results suggest that, in this region of the X chromosome, LD is not a monotonic function of the distance between markers, but is more a property of the particular location in the human genome.     

Research on 3D Micro-nano Processing Reported on Nature

The latest issue of Nature reported in its Research Highlights ( see " Lithography: Luminous Lizards", Nature, Vol. 451, p868, Feb. 21, 2008) that a group of researchers from the Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS) achieved the new progress in 3D microstructures of nanometer composites using the multiphoton nanoprocessing technology.     

基于曲波变换的地震数据压缩感知重构算法

为提高地震数据压缩感知重构的信噪比和保真度, 提出一种基于曲波变换的地震数据压缩感知重构算法。建立了地震数据压缩感知重构模型, 分析了基于曲波变换稀疏表示的地震数据各尺度之间能量与熵的分布特性, 结合分块压缩感知技术降低随机观测的计算复杂度, 利用曲波变换稀疏表示高频区域各尺度之间的相关性, 设计了随信息熵变化的自适应双变量收缩阈值迭代重构的方法。实验结果表明, 在相同的采样率下,该算法重构的地震数据峰值信噪比提高了1. 5 dB 以上, 并且具有良好的细节信息保持能力。     

大型地下洞室群变形实测与数值模拟

以某水电站大型地下洞室群开挖为例,建立了三维数值分析模型,研究了洞室群开挖后洞周围岩的变形特性并分析了锚索应力损失对周围岩体变形和应力状态的影响;通过模拟结果与实测结果进行对比,分析模拟方法的合理性和支护方案的可行性.结果表明,围岩水平位移在洞室边墙中部最大,竖向位移在洞室拱顶最大,在洞室交叉部变形也较为显著;模拟结果与实测结果较接近,能良好地反映洞室实际开挖的过程和围岩的变形规律;锚索预应力损失达到某一程度时会使围岩水平位移显著增大.     

基于RSM-GA法的薄壁蜡模压蜡过程收缩率建模与优化

基于响应面法(RSM),通过一系列的实验建立了薄壁蜡模壁厚方向的收缩率与压蜡参数之间的数学模型,并对模型的合理性与充分性进行了方差分析,对压蜡过程中工艺参数对尺寸收缩率的影响进行了敏感性分析.为了减小收缩率,基于遗传算法(GA)对工艺参数进行了全局优化.     

Predictability of Plastic Parts Behaviour Made from Rapid Manufacturing

One of the most important issues to resolve in parts manufactured from rapid manufacturing (RM) technologies is to know their behavior working under real conditions. Total quality manufacturing (TQM) is only possible if mechanical properties are well known in the design stage depending on the processing parameters. This work is mainly focused on testing of several samples made with different selective laser sintering (SLS) parameters and technologies. This procedure is the starting point to establish a basis for designing for RM and the standardization of RM testing. The experiments and the analysis of variance (ANOVA) analyzed the effects of several factors on mechanical properties. The SLS technologies were 3DSystem and EOS. The results show which factor has a large effect on the variables and the interaction between them. The conclusions are very useful for developing rules for designing (designing for RM) and creating new standard rules (ISO, AISI, and DIN) for RM materials and parts testing. The ANOVA gives a better knowledge of the effects of these factors and eliminates unimportant parameters.     

德国的危机预防信息系统

对巨大灾难的管理(包括自然和人为的灾难)要获得高效、取得成功,决策者必须要及时获取相关信息。德国早年的一些大规模的灾难,例如2002年8月易北河的大洪水、1999年12月发生在德国南部的Lothar暴风雪,都显示了灾难管理部门只获取了部分的必需信息,在联邦政府和受灾地区的灾难反应部门间的通讯信息流也是极度不足。有鉴于此,2001年夏天德国内政部门决定建立“危机预防信息系统”(GermanEmergencyPlanningInformationSystem/简称deNIS)。在此基础上开发的denISⅡ的目标则是为市     

Microstructural evaluation and nanohardness of an AlCoCuCrFeNiTi high-entropy alloy

An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.     

科学饲料管理系统的研究与实现

本文论述了“清真畜产品规范生产与质量认证系统”中“科学饲料管理系统”的设计过程以及研发成果。该系统针对奶牛、肉牛和肉羊等特色动物养殖中饲料合理化和科学化的要求,对异构数据集成整合,即在客户端将各种异构数据转换成XML格式文件,通过Internet网络上传至服务器指定文件夹,并进行字段映射和数据整理,最后将经过整理的数据导入服务器数据库的相关表中,从而建立了宁夏地区特色动物饲料原料成分及配比数据库（知识库）,实现了全区共享的饲料配方服务管理平台、事务处理平台等。“科学饲料管理系统”的应用有助于改进奶牛等动物饲料配方的科学性,提高饲料的利用率,达到节本增效的目标,为提高养殖业管理水平与畜产品生产效率提供信息化技术支撑。