便梁加固铁路线箱桥顶进施工技术的研究

D型便梁加固线路顶进箱桥施工技术已得到广泛应用.本文结合马鞍山江东大道宁芜铁路既有线框架箱桥施工实践,对D型便梁加固线路顶进施工工艺和技术特点进行了研究,实践证明效果良好.     

强流束晕-混沌的幂函数反馈控制法

文章设计了一种形式简单的幂函数反馈控制器。数值模拟结果显示，该方法能有效实现5种不同初始分布强流离子束的束晕-混沌控制，尤其是该方法控制后全局高斯分布的晕度也达到了零。     

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.     

GFRP加固混凝土梁受弯性能试验研究

对15根玻璃纤维布加固的钢筋混凝土梁进行了试验研究。试验结果表明,玻璃纤维布加固的钢筋混凝土梁抗弯承载力显著提高,加固效果明显,但要有足够的粘贴长度以避免发生剥离破坏。     

纤维塑料筋混凝土研究新进展

纤维塑料筋是一种性能优越的高性能复合材料，适用于土木工程混 凝土结构。与 普通钢筋相比，纤维塑料筋具有抗拉强度高、抗腐蚀性能优良、重量轻、弹模低、抗剪和抗 挤压强度低等特点。目前，纤维塑料筋在国外已成为结构工程领域研究热点。自2000年以来 ，在国家自然科学基金的资助下，我们较系统地开展了纤维塑料筋混凝土的试验与理 论研究，本文介绍有关最新研究成果。     

双曲拱坝体型优化设计

采用改进的复合型法对某双曲拱坝进行了体型优化设计，优化过程中结构重分析采用线弹性有限单元法，本文分别三心圆、地数螺旋线，抛物线，双曲线，椭圆和一般二次曲线六种体型进行了研究，结果表明，一般二次曲线体型的坝体方量，最大拉应力较其它几种体型均为最小，其优化后拱坝的混凝土方量和最大拉应力比原设计方案分别降低约8．77％和20％。     

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.     

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)     

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。     

钢连梁带缝剪力墙结构的研究

提高连系梁的延性是改善剪力墙结构搞震性能的关键．以钢连梁代替现有的带缝混凝土连梁的新结构，能更好保证其设计破坏荷载，减少施工困难，有效地作为地震能耗能机构．