DELTA系统——值得再次推介的国际分类学描述信息处理工具

DELTA(description language for taxonomy)系统是一个用于生物分类学描述的计算机信息处理系统,也是国际植物分类数据工作组(International Working Group on Taxonomic Databases for Plant Sciences)选定的国际数据交换通用标准。DELTA系统主要功能是对分类学的形态描述进行规范化处理,并在此基础上进行分类群的自动描述、交互式鉴定和分类信息管理等。随着DELTA系统近40年的研制和改进,以及因特网便捷的信息传输和交流,该系统被越来越多地应用于植物分类学研究。作者简要介绍了该系统的结构、功能、获取途径以及使用方法,对DELTA系统所包含的子程序的功能、用途及运行方式进行了简要分析,以期推动该系统在中国植物分类学研究中的普及和应用。

Optimal arrangement for pressure measurement points in working chamber of earth pressure balance shield

In order to exactly provide scientific basis for pressure dynamic balance control of working chamber of earth pressure balance shield (EPBS),study on optimal arrangement of pressure measurement points in working chamber was conducted. Based on mathematical description of optimal arrangement for pressure measurement points,fuzzy clustering analysis and discriminant analysis were used to divide pressure regions of nodes on bulkhead. Finally,the selection method of optimal measurement points was proposed,and by selecting d6.28 m EPBS as study object,the case study was conducted. By contrast,based on optimal arrangement scheme of pressure measurement points,through adopting weighted algorithm,the absolute error mean of equivalent pressure of working chamber is the smallest. In addition,pressure curve of optimal arrangement points presents parabola,and it can show the state of pressure distribution on bulkhead truly. It is concluded that the optimal arrangement method of pressure measurement points in working chamber is effective and feasible,and the method can provide basis for realizing high precision pressure control of EPBS.

Notes on the comb-footed spiders of genus Theridion(Araneae:Theridiidae),with description of a new species from Yuelushan Mt.,China

This paper presents five Theridion species from the Yuelu Mt.,Changsha,including one new species and four known species:Theridion albioculum(♀♂);T.longipalpum(♂);T.obscuratum(♂);T.subundatum sp.nov.(♂♀);T.undatum(♀♂).We provided the morphological description,photos for the new species and photos for the known species in current paper.