烷基硫醇在不同固定相上的QSRR研究

计算出体系中烷基硫醇化合物的各种结构参数,以优选出的分子连接性指数和量化参数为结构描述符,首次采用反向传播算法(BP)人工神经网络、径向基函数网络(RBF)2种非线性方法建立了参数少且精度高的定量结构-色谱保留相关(QSRR)模型,预测了烷基硫醇在4种极性固定上的气相色谱保留指数(RJ)。结果表明:在4种固定相上建立的BP模型均优于RBF模型且非线性方法(BP、RBF)优于文献中多元线性回归(MLR)方法,所建定量结构保留关系(QSRR)模型具有良好的稳定性和预测能力。     

醇类化合物色谱保留指数与结构参数定量关系的研究

采用拓扑指数(~mQ)、定位基参数(S_(ox))与醇在6种固定相上的气相色谱保留指数值(RI)进行了相关分析,发现RI与上述参数间存在良好的相关性,其关系式可表示为：RI=d (a~0)Q-(b~1)Q cS_(ox),其中a、b、c、d为系数。相关系数均大于0．98。继以留一法(Leave-one-out,LOO)进行交互检验,相关系数RCV均大于0．97。说明所建定量结构-保留关系(QSRR)模型具有良好的稳定性和预测能力,较好地揭示了醇类物质在不同固定相上气相色谱保留指数的变化规律。     

酯类化合物气相色谱定量结构保留关系的研究

采用分子电性距离矢量(MEDV)表征酯类化合物的分子结构,同时运用多元线性回归技术建立了81个酯类化合物,在2种固定相(Carbowax1540和Cqualane)上,气相色谱保留指数(RI)与MEDV的定量结构-色谱保留关系(QSRR)模型。在2种固定相上的QSRR模型的建模计算值复相关系数(Rcum)、留一法(leave-one-out)交互校验复相关系数(QCV)分别为0.9968和0.9958(Carbowax1540);0.9935和0.9908(Cqualane),结果表明MEDV能理想地表征酯类化合物的分子结构,所建模型具有良好稳定性和预测能力。     

分子结构分区方法及在二硫化合物QSRR研究中的应用

从二硫化合物分子结构特征出发,并结合色谱分离机制,将分子结构进行分区处理,通过所建构的总拓扑立体效应指数(TTSEI)、顶点度-距离指数(VDI)、奇偶指数(OEI)、极化效应指数(PEI)等拓扑结构参数,用多元线性回归(MLR)方法获得了二硫化合物在4种不同极性固定相上气相色谱保留指数(RI)与4个结构参数之间的定量结构-色谱保留相关(QSRR)的统一模型,相关系数均大于0.98,以留一法(Leave-one-out)进行交互检验,相关系数R_(cv)均大于0.97。模型方程用于预测各二硫化合物的气相色谱保留指数其稳定性和准确性俱佳。     

多氯代二苯并呋喃QSRR的拓扑量子方法研究

由于分子邻接矩阵能很好地表征分子的结构,以多氯代二苯并呋喃中不同的分子碎片实测的第一电离能为主元,构建分子的拓扑邻接矩阵,解得其特征根,参照分子轨道(MO)的概念。指定其中2个特征根为分子轨道的前线轨道HOMO,运用多元线性回归法,将矩阵特征根HOMO和分子体积作为参数,对多氯代二苯并呋喃在三种不同固定相中的色谱保留指数(RI)和相对保留时间(RRT)作相关分析,其相关系数都在0．968以上。所得方程的良好相关性,说明该方法合理、有效。     

用分子拓扑指数预测饱和酯类化合物的气相色谱保留指数

提出修正的分子极化效应指数(MPEIna)、烷基的极化效应指数(PEI)、奇偶指数(OEI)、均衡电负性(Xeq)、立体效应指数(SVij)等拓扑结构参数,运用多元线性回归(MLR)方法获得了饱和酯类化合物在7种不同极性色谱柱上的结构-保留相关(QSRR)模型,模型方程为:RI=aXeq×PEI bOEI-cSVij dXeq×MPEIna f,其中a、b、c、d、f为系数,相关系数均大于0.99,以留一法(Leave-one-out)进行交互检验,相关系数Rev均大于0.99,表明由上述分子结构参数得出的模型方程用于预测各饱和酯类化合物的气相色谱保留指数其稳定性和准确性俱佳,且较好地揭示了饱和酯类化合物在不同极性色谱柱上气相色谱保留指数的变化规律.     

交互柱法研究固定相极性参数对饱和酯QSRR建模的影响

用Chemoffice建构和优化了90个饱和酯的分子结构,运用Dragon6.0计算了2337个结构参数,采用Minitab15进行逐步回归筛选出2个结构参数SpPosA_Dz(Z)和RDF020p,通过多元线性回归方法构建了饱和酯化合物在7种不同极性色谱固定相上的定量结构-色谱保留相关关系(QSRR)模型,模型方程的相关系数在0.99以上。在此基础上建立交互柱QSRR模型,考察色谱固定相极性参数麦克雷诺常数(Mp)对保留指数的影响。研究结果表明:包含固定相极性参数Mp的交互柱QSRR模型方程对饱和酯化合物在不同极性色谱柱上的色谱保留指数都能得到较准确的预测结果。     

QSRR结合人工神经网络预测多氯联苯色谱保留时间

采用量子化学密度泛函B3LYP/6-311+G~*,在高斯09软件上计算了32个多氯联苯类化合物的电子结构参数:筛选出影响化合物色谱保留时间显著的5个变量,并建立其结构与保留时间之间的定量关系(MLR模型);同时,利用人工神经网络(artificial neural network,ANN)法建立相应的QSRR模型(ANN模型)与之对比。所建MLR模型的相关系数R=0.904,标准误差Se=0.542;ANN模型的相关系数R=0.981,标准误差Se=0.213。表明所建立的QSRR模型的稳定性和预测能力良好。结果表明,多氯联苯化合物的色谱保留时间与前沿轨道能级差ΔE和分子最高占有轨道能E_H成正比例关系。所建模型为预测多氯联苯化合物的色谱保留时间提供理论指导。     

多氯代二苯并呋喃定量结构性质关系的研究

基于定量结构-性质相关(QSPR)研究多氯代二苯并呋喃化合物的性质具有重要意义。采用分子电性距离矢量(MEDV)表征135个多氯代二苯并呋喃化合物(PCDFs)的分子结构,运用多元线性回归(MLR)技术,同时采用逐步回归结合统计检测筛选模型变量,建立PCDFs的气相色谱保留指数(RI)、正辛醇/水分配系数(LogK_(ow))、基于2种色谱条件下的2组气相色谱保留时间与MEDV的QSPR模型,模型的线性相关系数均在0.8971～0.9963之间。继用留一法和外部样本检验模型稳定性能。结果:所建QSPR模型的稳定性和预测能力良好。     

基于Monte Carlo采样模型集群分析对定量结构-色谱保留相关关系(QSRR)常用建模方法的比较研究

本文收集了环烷烃类、环烯烃类、酮类、胺类、醚类、酯类等有机物在固定相角鲨烷和SE-30上的气相色谱保留指数,并采用基于Monte Carlo采样的模型集群分析(Monte Carlo sampling model population analysis,MCS MPA)方法进行了定量结构-色谱保留指数相关关系建模方法的比较研究。对于两种固定相上的有机化合物,分别采用不同的分子描述符予以表征,分子描述符的选择基于统计学与遗传算法。采用的建模方法包括多元线性回归(multivariate linear regression,MLR)、支持向量机回归(support vector machine,SVM)、径向基函数人工神经网络方法(radial basis function artificial neural networks,RBF ANN),通过所建模型预测了独立外部测试样本的气相色谱保留指数。研究结果表明,对于本文所研究的数据,SVM回归方法的建模效果优于MLR与RBF ANN方法。     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.