浅谈协同商务对会计信息化的影响

协同商务对会计信息化提出了新的挑战.文章探讨了协同商务的含义,并在此基础上归纳了协同商务对会计信息化的影响.     

热处理对以Al2O3为绝缘层的并五苯薄膜晶体管性能的影响

采用阳极氧化法制备了Al_2O_3绝缘材料,并制备了以Al_2O_3为绝缘层的并五苯薄膜晶体管器件(OTFT)。Al_2O_3绝缘层经过10 min 350℃氢热处理后,OTFT迁移率比未经氢热处理的增大近20倍,且阈值电压降到了-7 V。Al_2O_3膜MIS结构电容—电压(C–V)特性的平带电压平移量数据表明,Al_2O_3膜经过热处理后,并五苯半导体与Al_2O_3绝缘体界面处以及绝缘体内缺陷态密度显著地降低,Al_2O_3绝缘层和并五苯半导体层之间的接触得到改善,这使得经热处理Al_2O_3膜的OTFT器件性能得到显著的改善。     

A second generation human haplotype map of over 3.1 million SNPs

We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations.     

Genome-wide detection and characterization of positive selection in human populations

With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms from the International HapMap Project Phase 2 (HapMap2). We used 'long-range haplotype' methods, which were developed to identify alleles segregating in a population that have undergone recent selection, and we also developed new methods that are based on cross-population comparisons to discover alleles that have swept to near-fixation within a population. The analysis reveals more than 300 strong candidate regions. Focusing on the strongest 22 regions, we develop a heuristic for scrutinizing these regions to identify candidate targets of selection. In a complementary analysis, we identify 26 non-synonymous, coding, single nucleotide polymorphisms showing regional evidence of positive selection. Examination of these candidates highlights three cases in which two genes in a common biological process have apparently undergone positive selection in the same population:LARGE and DMD, both related to infection by the Lassa virus, in West Africa;SLC24A5 and SLC45A2, both involved in skin pigmentation, in Europe; and EDAR and EDA2R, both involved in development of hair follicles, in Asia.     

河北省御道口牧场气候生产潜力估算

御道口牧场位于河北省围场县北部坝上地区,是河北省畜牧业生产的重要产区.根据牧场多年降水和气温等气象观测资料,同时考虑地形因素和最小面积的限制,对御道口牧场的气候生产潜力进行了估算.得出牧场的气候生产潜力在3.75～5 t·hm-2·a-1之间,牧场内适合发展人工草地的平地和缓坡(＜5°)约占总土地面积的76.5%.     

塔里木河流域中下游典型地物光谱变化规律

由于塔里木河流域中下游距离河道在垂直向的差别,以及气候与人为因素的影响,使植被的空间分布具有异构性.典型地物光谱变化的研究为中下游生态环境的遥感监测提供了基础,实验研究表明:绿色全荣植物中,棉花由于其具有明显绿峰、水分吸收谷和近红外的高反射峰而更加容易识别,其他植物主要差别则集中在550,680,1420 nm附近的反射峰、吸收谷和1920～2500 nm之间的反射率;与绿色植被相比,枯枝的光谱在可见光部分的绿峰和红光吸收谷不明显,但在可见光部分波形有所差别,而与流沙土壤光谱相比,各波段反射率变化较大;对比不同荣枯比例的植物光谱发现,同一种植物随着荣枯配比的变化,除可见光绿峰、近红外反射峰和各水分吸收谷变化外,最明显的是在近红外1420～1820 nm之间和短波红外1920～2500 nm之间反射率随着枯枝的比例增加而明显升高;关于土壤光谱,中下游各断面占主要类型的流沙土光谱相差不大,但是盐碱土和含有一定水分的盐碱土则变化较大,而且反射率基本低于流沙土,结壳土则除在近红外和短波红外部分变化更加平缓而有所差别外,其余波段接近流沙土;同样的土壤背景下,近红外和短波红外部分反射率的差别能够在一定程度上反映覆盖度的变化.     

基于人的信息处理模型分析操作人员视觉信息处理过程

报告了由知觉、思维、运动３个处理器和短期记忆、工作记忆和长期记忆构成的研究用计算机实现 人的信息处理模型;把人的信息处理模型安装在一台PC机上,模拟生产操作人员监视锅炉厂模拟机计算机屏幕 的过程表明,视觉信息处理过程取决于画面因素、人的身心状态和知觉处理器参数等与实际生产操作人员的行 为特征相符。此模型可以用来分析工业生产中人为操作失误的发生机制,以预防和减少事故发生。     

安全性第一准则下的组合贷款模型

提出了一种在概率准则意义下的组合贷款模型,并设计了基于随机模拟的混合优化算法进行求解。 该算法突破了各种贷款收益率必须服从正态分布的假定,可对贷款收益率是任意分布形式的模型进行求解。 经数值仿真,验证了算法的可行性。     

基于聚类非参数检验的动态停车需求分布特征

为了探索动态停车需求的分布特征,提出聚类非参数检验分析方法.该方法按照个体-组-类的顺序对多时段随机变量进行聚合,在各聚合阶段运用相应的非参数检验方法校核结果,在确保拟合精度的同时,采用相应的模型描述动态随机变量的分布特征.结合该方法的运用,从问题确定、数据调查、数据处理与分析以及分布特征的归纳总结等环节详细阐述了动态...     

滚压对6061铝合金微动磨损性能的影响

应用一种恒力式滚压工具,依据Box-Behnken中心组合设计原理,以车削进给量、滚压力和滚压次数为自变量,以在SRV IV实验机上实现的100℃下的无润滑条件和润滑条件下的微动磨损体积为响应值,对6061铝合金进行滚压后的微动实验,推导出了非平面微动磨损体积的计算公式,并对微动实验中的摩擦系数、试样初始表面粗糙度和磨...