对象关系数据库系统模型及映射规则

在业务逻辑层和关系数据库的物理存储结构中间增加一个O R代理层,提出了一个对象关系数据库系统的三层模型,并对系统模型的各个层次进行了详细的功能设计和分析;总结出了代理层O R映射的4条基本规则,并对各自的优缺点进行了比较.结果表明,该模型在实际应用中存在有效性.     

基于SQL Server 2000的关系数据与XML的映射研究

在阐述XML文档逻辑结构的基础上 ,对基于SQLServer 2 0 0 0的关系数据与XML的映射规则作了介绍 ,并对关系数据与XML映射的具体实现进行了研究     

三种数据库的应用比较

介绍关系数据库(RDB)、对象数据库(OODB)和XML本源数据库(NXD),分析了它们各自的特点.重点介绍了XML本源数据库,并分析了发展前景.比较三种数据库技术在工程应用方面的特点和优势,讨论它们各自适合的应用场合,指出XML本源数据库在工程应用方面的巨大优势.     

催化动力学光度法测定抗癌中草药中痕量硒Ⅰ.溴酸钾—罗丹明B体系

研究了硝酸介质中痕量硒(Ⅳ)催化溴酸钾氧化罗丹明B的褪色反应及动力学条件, 建立了动力学光度法测定痕量硒(Ⅳ)的新方法, 其灵敏度为0.905 μg·L-1, 测定范围0～9.6 μg·L-1。用于测定抗癌中草药中的硒(Ⅳ), 获得了满意的结果。     

A Novel Ranking Framework for Linked Data from Relational Databases

This paper investigates the problem of ranking linked data from relational databases using a ranking framework. The core idea is to group relationships by their types, then rank the types, and finally rank the instances attached to each type. The ranking criteria for each step considers the mapping rules and heterogeneous graph structure of the data web. Tests based on a social network dataset show that the linked data ranking is effective and easier for people to understand. This approach benefits from utilizing relationships deduced from mapping rules based on table schemas and distinguishing the relationship types, which results in better ranking and visualization of the linked data.     

关于RDB的几个新的线性分布模型

通过数组覆盖设计程序探索 ,建立了关于RDB的几个新的线性模型。设RDB直尺长为len ,有n条刻度 ,实现完全度量的刻度分布用f(len ,n)来表示 ,得到以下三个线性分布模型。f(8n - 31,n) ={ 1,4 ,5 ,8,8,… ,8,3,1,2 ,1} ;f(9n - 4 1,n) ={ 1,4 ,3,4 ,9,9,… ,9,5 ,1,2 ,2 } ;f(10n - 5 5 ,n) ={ 1,1,3,4 ,10 ,10 ,… ,10 ,1,2 ,3,6 ,2 ,3}。通过这些线性模型 ,在n一定的实用范围内 (n <19)改进了文 [5 ]提出的二次模型推出的结论。     

XPDL与关系数据库之间的映射

XPDL( XML Process Definition Language)是工作流管理联盟(WFMC)制定的工作流模型标准,而关系数据库是当前很多工作流厂商存放工作流数据的首选方法.讨论了XPDL与关系数据库(RDB)之间的映射原理及映射方法,并由此建立了映射文件,从而方便了XPDL与RDB之间的双向数据转换.     

RDB直尺的两类刻度分布模型

本文建立关于RDB直尺的两类刻度分布模型,依据这些模型改进了米勒(Miller)关于RDB的一个结论。     

Spectral quality assessment and application for gel-based matrix-assisted laser desorption ionization-time of flight tandem mass spectrometer

Gel-based matrix-assisted laser desorption ionization-time of flight tandem mass spectrometer (MALDI TOF/TOF MS) is one of the dominant methods of current proteomics, utilizing both peptide mass fingerprinting (PMF) and peptide fragment fingerprinting (PFF) for protein identification on a spot-to-spot basis. However, the unique impact of the quality of the corresponding mass spectrometry spectra remains largely unreported, and has motivated the development and use of an automatic spectra-assessment method. In this study, a multi-variant regression approach has been utilized to assess spectral quality for both PMF and PFF spectra obtained from MALDI TOF/TOF MS. The assessment index has been applied to investigations of MASCOT search results. Systematic examination of two large-scale sets of human liver tissue data has proved that spectral quality was a key factor in significant matching. Based on large-scale investigations on individual PMF search, individual PFF search and their combination, respectively, the filtering of bad quality spectra or spots proves to be an efficient way to improve search efficiency of all search modes in MASCOT. Meanwhile, a validation method based on score differences between normal and decoy (reverse or random) database searches is proposed to precisely define the positive matches. Further analysis showed that spectral quality assessment was also efficient in representing the quality of 2-DE gel spots and promoted the discovery of potential post-translation modifications.