In order to provide an effective way to create descriptive records for electronic resources and the options to assist librarians in providing their users with enhanced access to Web resources,OCLC has developed anothe...In order to provide an effective way to create descriptive records for electronic resources and the options to assist librarians in providing their users with enhanced access to Web resources,OCLC has developed another new product of cataloging service named CORC.The characteristics of CORC are detailed in this paper based on the author’s experience of using CORC in the United States.Then the paper provides some suggestions for improving the sharing of cooperatively cataloged Web resources in China.展开更多
高温超导CORC(conductor on round core)电缆失超时的热负荷严重威胁了低温系统和电缆本体的安全稳定运行。受微米级超导薄膜制备工艺等的影响,CORC电缆并绕的多根高温超导带材不均匀。为分析不均匀临界电流对CORC电缆失超特性的影响,...高温超导CORC(conductor on round core)电缆失超时的热负荷严重威胁了低温系统和电缆本体的安全稳定运行。受微米级超导薄膜制备工艺等的影响,CORC电缆并绕的多根高温超导带材不均匀。为分析不均匀临界电流对CORC电缆失超特性的影响,该文搭建了基于三维TA方程的有限元模型。以降维的带材曲面为求解区域,以等效的电流密度为求解变量,失超模型在同一几何中表达超导和常导两种属性,构建电流和电势两种约束。在导体域建立降维的热模型,用以考虑损耗和传热的影响;在全局建立等效的电路模型,用以控制并联导体的分流。进一步地,耦合模型考虑温度依赖的接头电阻以模拟CORC电缆带材的烧断和电流的突变。结果表明,非均匀高温超导带材影响了电流重分配的动态响应,加快了局部失超的发展过程。展开更多
对网络资源实行书目控制是对其进行开发、利用的有效途径之一。网络资源数量大、增长快、稳定性小,唯有走合作编目之路才能达到事半功倍的效果。OCLC 顺应网络资源发展的趋势推出 CORC 计划,把“编目资源共享”的概念引入网络资源的组...对网络资源实行书目控制是对其进行开发、利用的有效途径之一。网络资源数量大、增长快、稳定性小,唯有走合作编目之路才能达到事半功倍的效果。OCLC 顺应网络资源发展的趋势推出 CORC 计划,把“编目资源共享”的概念引入网络资源的组织与控制,其中颇有值得我们思索与借鉴的地方。展开更多
文摘In order to provide an effective way to create descriptive records for electronic resources and the options to assist librarians in providing their users with enhanced access to Web resources,OCLC has developed another new product of cataloging service named CORC.The characteristics of CORC are detailed in this paper based on the author’s experience of using CORC in the United States.Then the paper provides some suggestions for improving the sharing of cooperatively cataloged Web resources in China.
文摘高温超导CORC(conductor on round core)电缆失超时的热负荷严重威胁了低温系统和电缆本体的安全稳定运行。受微米级超导薄膜制备工艺等的影响,CORC电缆并绕的多根高温超导带材不均匀。为分析不均匀临界电流对CORC电缆失超特性的影响,该文搭建了基于三维TA方程的有限元模型。以降维的带材曲面为求解区域,以等效的电流密度为求解变量,失超模型在同一几何中表达超导和常导两种属性,构建电流和电势两种约束。在导体域建立降维的热模型,用以考虑损耗和传热的影响;在全局建立等效的电路模型,用以控制并联导体的分流。进一步地,耦合模型考虑温度依赖的接头电阻以模拟CORC电缆带材的烧断和电流的突变。结果表明,非均匀高温超导带材影响了电流重分配的动态响应,加快了局部失超的发展过程。
