人口老龄化对我国居民消费需求的影响

人口老龄化作为社会发展到一定阶段的产物,必然会对经济社会产生重要影响。2000年第五次全国人口普查显示,中国已经进入老龄化社会。积极开展人口老龄化问题的研究,尤其是对经济社会的影响,并进行相应的政策引导,是妥善解决老龄化问题,维系社会和谐的必然选择。本文着重分析了人口老龄化对我国居民消费需求的影响,并相应提出了解决建议。     

原子激光的传输和控制

综述了原子激光和光子激光之间的相似和区别以及原子激光器的最新进展情况，在此基础上，还介绍了实验和理论是如何利用原子激光和光子激光之间的区别实现对原子激光的传输和控制的，主要包括发散角、横向模型，利用磁光场构成的元件实现对它的控制以及可能会出现的成丝现象等。     

带刚性连梁混凝土短肢剪力墙结构的有限元分析

通过大型有限元软件ANSYS对带刚性连梁的双肢短肢剪力够结构的刚度以及混凝土的非线性进行计算和分析。结果显示:设置刚性连粱可以有效地增强短肢剪力墙结构的侧移刚度,同时具有较好的延性性能。     

Effect of corrosion on bond behavior and bending strength of reinforced concrete beams

There is growing concern for corrosion damage in reinforced concrete structures with several decades’ service. Pullout tests and beam tests were carried out to study the effect of reinforcement corrosion on the bond behavior and bending strength of reinforced concrete beams. The bond strength of plain bars and concrete initially increases with increasing corrosion, then declines. The turning point depends on the cracking of the concrete cover. The bond strength of deformed bars and concrete increases with corrosion up to a certain amount, but with progressive increase in corrosion, the bond strength decreases, and the cracking of the concrete cover seems to have no effect on the bond strength. On the basis of test data, the bond strength coefficient recommended here, which, together with the bond strength of uncorroded steel bars and concrete, can be used to easily calculate the bond strength of corroded steel bars and concrete. The bond strength coefficient proposed in this paper can be used to study the bond stress-slip relationship of corroded steel bars and concrete. The bending strength of corroded reinforced concrete beams declines with increasing reinforcement corrosion. Decreased bending strength of corroded RC beam is due to reduction in steel bar cross section, reduction of yield strength of steel bar, and reduction of bond capacity between steel bar and concrete. Project supported by Cao Guanbiao Key Technology Development Founding of Zhejiang University and Construction Ministry of China.     

利用奇异函数自动处理变截面梁在复杂载荷作用下的变形

该文利用奇异函数，结合工程数学的方法，运用计算机自动处理变截面梁在复杂载荷作用下的变形问题。     

Polycrystalline ZnS<Subscript>x</Subscript>Se<Subscript>1−x</Subscript> thin films deposited on ITO glass by MBE

MBE growth of ZnS_xSe_1−x thin films on ITO coated glass substrates were carried out using ZnS and Se sources with the substrate temperature ranging from 270°C to 330°C. The XRD σ/2σ spectra resulted from these films indicated that the as-grown polycrystalline ZnS_xSe_1−x thin films had a preferred orientation along the (111) planes. The evaluated crystal sizes as deduced from the FWHM of the XRD layer peaks showed strong growth temperature dependence, with the optimized temperature being about 290 °C. Both AFM and TEM measurements of these thin films also indicated a similar growth temperature dependence. High quality ZnS_xSe_1−x thin film grown at the optimized temperature had the smoothest surface with lowest RMS value of 1.2 nm and TEM cross-sectional micrograph showing a well defined columnar structure. Project supported by the National Science Council of PRC (No. 59910161981) and RGC grant from the Hong Kong Government under Grant (No. NS-FC/HKUST 35)     

模糊控制方法在球杆系统中的应用

该文在MATLAB软件Simulink环境下建立了球杆的仿真模型和实时控制模型,并设计了双环模糊控制器.应用控制软件Wincon对系统进行了实时的控制,取得了较好效果.     

新规则下女子竞技体操平衡木成套动作编排特征及趋势

探讨2013年竞技体操平衡木规则最新变化的基础上,对新规则实施后最近的大型赛事上,我国运动员和世界优秀运动员成套动作编排内容进行统计分析,探索出新规则下女子平衡木成套动作的编排特征,以及对我国女子平衡木发展趋势的影响,为教练员、运动员提供一定的理论依据。本文主要采用文献资料法、专家访谈法对2013年新规则主要变化与发展方向进行分析,进而通过录像观察法、数理统计法等研究方法,分析新规则实施后,参加全运会和世界单项锦标赛前八名运动员的成套动作。     

钢桁架作为箱梁横隔板的研究

采用钢桁架代替箱梁混凝土横隔板的办法,可以解决箱梁跨中的混凝土横隔板自重大,施工不易控制,容易开裂的问题。计算采用横隔板及顶板前后各一部分截取出来的隔离体为模型,把将横隔板看作简支梁、悬臂梁或连续梁,进行恒载和活载分配,得到内力后根据允许应力法计算桁架强度,由此得到钢桁架作为箱梁横隔板一般计算方法。