砖砌体裂缝的原因分析及防治

建筑工程质量症害不仅影响建筑工程的使用,严重还会给国家和人民生命财产带来巨大损失,除了要求高度的安全责任感外,还应该掌握和分析症害发生的原因及预防处理的方法,才能正确处理症害。砌体裂缝又是对建筑物危害程度较大的症害,参与了国内有关预防,处理方法,提出了砌体砌体裂缝产生原因、预防措施、处理方法。     

提高开放教育金融本科毕业论文质量的思考

毕业论文是培养学生综合应用专业知识分析和解决工作实践中的具体问题的重要的实践性教学环节。开放教育金融本科学员的毕业论文质量存在诸多问题,原因不仅有学员自身的,也包括指导教师、办学单位和试点教学管理等方面的,因而要提高开放教育金融本科毕业论文质量,必须从全方位入手。     

上海松江大学城图书馆资源共享研究

本文通过对松江大学城六所高校馆资源现状的调查和分析，探讨了大学城图书馆资源共性的必要性和可行性，提出了实现松江大学城图书馆资源共享的思路与对策。     

基于ASP的数字签名解决方案研究

以ASP为开发工具，对数字签名解决方案进行研究，提出了具体的实现方法。     

Numerical investigation of cavitating flow behind the cone of a poppet valve in water hydraulic system

Computational Fluid Dynamics (CFD) simulations of cavitating flow through water hydraulic poppet valves were performed using advanced RNGk-epsilon turbulence model. The flow was turbulent, incompressible and unsteady, for Reynolds numbers greater than 43000. The working fluid was water, and the structure of the valve was simplified as a two dimensional axisymmetric geometrical model. Flow field visualization was numerically achieved. The effects of inlet velocity, outlet pressure, opening size as well as poppet angle on cavitation intensity in the poppet valve were numerically investigated. Experimental flow visualization was conducted to capture cavitation images near the orifice in the poppet valve with 30° poppet angle using high speed video camera. The binary cavitating flow field distribution obtained from digital processing of the original cavitation image showed a good agreement with the numerical result. Project supported by the National Natural Science Foundation of China (No. 59835160) and Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry of China (No. 50175097)     

完全立方型三次函数为系数的线性微分方程

通过把线性微分方程化为可逐次积分的线性微分方程，找出了求这类方程通解的方法与理论，并给出了严格的证明和应用实例。     

高速铁路超大断面隧道施工方法数值模拟研究

针对高速铁路软弱、浅埋超大断面隧道,采用双侧壁导坑法、三台阶七步法两种施工方法分别进行三维数值模拟和开挖方法的科学性进行对比分析,结果表明:在施作大管棚超前支护的前提下,三台阶七步法比较合理.研究结论为同类工程的设计和施工提供理论参考.     

Inter-Parietal White Matter Development Predicts Numerical Performance in Young Children

In an effort to understand the role of interhemispheric transfer in numerical development, we investigated the relationship between children's developing knowledge of numbers and the integrity of their white matter connections between the cerebral hemispheres (the corpus callosum). We used diffusion tensor imaging (DTI) tractography analyses to test the link between the development of the corpus callosum and performance on symbolic and non-symbolic numerical judgment tasks. We were especially interested in the interhemispheric connections of parietal cortex in 6-year-old children, because regions of parietal cortex have been implicated in the development of numerical skills by several prior studies. Our results revealed significant structural differences between children and adults in the fibers of the corpus callosum connecting the left and right parietal lobes. Importantly, these structural differences were predictive of individual differences among children in performance on numerical judgment tasks: children with poor numerical performance relative to their peers exhibited reduced white matter coherence in the fibers passing through the isthmus of the corpus callosum, which connects the parietal hemispheres.     

怎样求函数EXP~((q))的可接受有理逼近

本文首先得到了函数R_(?)~s(q)是函数exp(q)的各类可接受有理逼近的必要条件,其次证明了exp(q)的含有s+t-p~*个自由参数的不低于p~*阶的有理逼近存在,且对于参数的每一组给定值,逼近式唯一.接着就逼近阶P≧2s-2,s≧2情形给出了exp(q)的双参数有理逼近R_s~s(q_ib_(s-1),b_s)和三参数有理逼近R_(s+1)~s(q_ib_(s-1),b_s,b_(s+1))的系数计算公式,并由此得到了求exp的含有多个自由参数的有理逼近的一般方法.     

基层电大教师专业发展:问题及化解

现代远程开放教育以新型的教育模式对电大教师提出了更新、更高的要求,但目前基层电大在教师专业发展问题上,不管是学校层面,还是教师自身层面,都存在不容忽视的问题,必须采取针对性措施进行有效的化解,使基层电大教师在专业知识和能力上得到全面提升,以承担起现代远程开放教育新的教育模式所赋予的全新角色和全新任务。