Zur Methodik der Messung der Aktivität von umschlossenen γ-Strahlungsquellen mittels Ionisationskammern

In der Arbeit wird über eine Empfehlung zur Methodik der Weitergabe der Aktivitätseinheit für umschlossene γ-Strahlungsquellen von den Normalen der metrologischen Slaatsämter der UdSSR (WNIIM) und der DDR (ASMW) an Normale niederer Ordnung berichtet. Die Weitergabe der Aktivitätseinheit geschieht durch Vergleich mittels Ionisationskammern. Die Empfehlung bezieht sich auch auf solche Fälle, in denen neben dem Hauptnuklid ein Verunreinigungsnuklid in der Quelle enthalten ist, sowie auf solche, bei denen unterschiedlicher Aufbau der zu vergleichenden Quellen vorliegt. Auβerdem umfaβt die Empfehlung die Methode der Fehlerrechnung.     

论高校系资料室的建设

本文简述了高校系资料室的产生、发展及现状，并阐述它的特点，最后提出利弊及改进意见。     

浅析高校图书馆的数字参考咨询服务

阐述了高校图书馆数字参考咨询服务的内涵，指出了数字参考咨询服务与传统参考咨询服务相比所具有的优势，分析了目前国内高校图书馆在开展数字参考咨询服务过程中存在的问题，并提出了相应的策略。     

Experimental PIV/V3V measurements of vortex-induced fluid–structure interaction in turbulent flow—A new benchmark FSI-PfS-2a

The investigation of the bidirectional coupling between a fluid flow and a structure motion is a growing branch of research in science and industry. Applications of the so-called fluid–structure interactions (FSI) are widespread. To improve coupled numerical FSI simulations, generic experimental benchmark studies of the fluid and the structure are necessary. In this work, the coupling of a vortex-induced periodic deformation of a flexible structure mounted behind a rigid cylinder and a fully turbulent water flow performed at a Reynolds number of Re=30 470 is experimentally investigated with a planar particle image velocimetry (PIV) and a volumetric three-component velocimetry (V3V) system. To determine the structure displacements a multiple-point laser triangulation sensor is used. The three-dimensional fluid velocity results show shedding vortices behind the structure, which reaches the second swiveling mode with a frequency of about 11.2 Hz corresponding to a Strouhal number of St=0.177. Providing phase-averaged flow and structure measurements precise experimental data for coupled computational fluid dynamics (CFD) and computational structure dynamics (CSD) validations are available for this new benchmark case denoted FSI-PfS-2a. The test case possesses four main advantages: (i) the geometry is rather simple; (ii) kinematically, the rotation of the front cylinder is avoided; (iii) the boundary conditions are well defined; (iv) nevertheless, the resulting flow features and structure displacements are challenging from the computational point of view. In addition to the flow field and displacement data a PIV-based force calculation method is used to estimate the lift and drag coefficients of the moving structure.     

魏源《洞庭吟》的当代反思

自然灾害成为当今社会的一个关键词。诚然,一些灾害诸如地震、台风等也许非人力因素可控;但连年洪灾,不仅有自然原因,更有人为因素。魏源《洞庭吟》即总结了当时长江水患形成的原因,批判了当时流行的天命说,认为上游乱砍滥伐山林造成水土流失,滨湖地区盲目围垦导致蓄洪区逐渐缩小,是造成水灾的重要原因,这一认识在当今无疑具有重要的借鉴意义。     

图书馆与档案馆网络参考咨询服务比较研究

对图书馆与档案馆的网络参考咨询现状进行了总结,通过比较图书馆与档案馆网络参考咨询服务的异同,借鉴图书馆网络参考咨询服务的一些经验,对档案馆网络参考咨询服务工作提出了一些建议。     

科技期刊著作权风险规避初探

基于广东省科技期刊著作权的保护现状,分析科技期刊的可能侵权情况,初探科技期刊规避著作权风险的方式.科技期刊与作品著作权人签订著作权转让合同是规避著作权风险的主要方式,要求作者提供《学术论文原创性声明》、原始数据证明材料,也是规避侵权的重要内容.合理引用参考文献,可避免学术不端的发生.     

Effect of Temperature on Henry's Constant in Simple Mixtures

Abstract

The molecular theory of dense fluids is progressing rapidly and its extension to mixtures is well underway. The purpose of this note is to call attention to a possibly serious difficulty in comparing experimental Henry's constants with those calculated from theory. The difficulty arises because whereas theorists choose temperature and density as independent variables, experimental equilibrium measurements on mixtures are often made along the saturation line where (at fixed composition) temperature and density are not both independent variables. Unless Henry's constants are defined with care, the effect of temperature on Henry's constants calculated from molecular theory may be qualitatively different from that observed.     

参考咨询馆员面临的挑战及因应之道

从图书馆信息中心的地位、大学生学习方式、师生对参考咨询馆员的依赖度3个方面讨论了互联网新技术对高校参考咨询馆员构成的挑战,并从高校参考咨询馆员自身的角度提出了3点因应之道。     

成年男性血小板正常参考值与地理环境的关系

为了给制定中国成年男性血小板正常参考值的统一标准提供科学依据,收集了中国100个单位测定的12670例成年男性血小板正常参考值,应用SPSS统计软件,运用相关分析和回归分析的方法,研究了其与7项地理因素指标的关系。