中小型林用装卸桥起升机构载荷率探讨

本文通过对起升机构载荷率的探讨,提出增加一个快速档可使装卸桥实现一机多用的设想。     

Extensible elastica solutions on the large deflection of fiber cantilever with circular wavy crimp (I)

Extensible elastica solutions of two-dimensional deflection of crimped fiber cantilever of circular wavy crimp were obtained for one end clamped boundary under concentrated, inclined and dead tip load Fiber was also regarded as a linear elastic material. Crimp was described as a combination of semicircular arcs smoothly connected with each other having constant curvature of all the same magnitude and alternative sign. Also the inclined load direction was taken into account. The solutions were expressed as the recursive forms of integrals in two different cases, which can also be transformed to elliptic integrals respectively. Comparing the data with inextensible ones was carried out. Consequently in the solution, the normal strain of neutral axis is expressed in terms of cross-sectional area, second moment of area and normalized load parameter. Examples of the circular cross-sectioned fiber are presented. As a result, the differences of normalized load between inextensible and extensible elastica solutions when the radius ratio becomes 0.1 were maximum Λ=0.1.     

高强复合纤维加固钢筋混凝土受弯构件的研究

分析研究了粘贴高强复合纤维加固受弯构件的受力过程，探讨了加固后钢筋混凝土梁正截面的破坏特征、受力特点以及影响因素，并提出正截面强度计算公式。试验结果表明：钢筋的配筋率与复合纤维的粘贴量对加固效果影响较大；实施桥梁构件加固时，要考虑加固前混凝土和钢筋已存的应力应变；复合玻璃纤维能有效地抑制裂缝的开展与延伸，为今后研究提供了参考。     

Nest site characteristics and male reproductive success in the upland bully, Gobiomorphus breviceps (Eleotridae)

Abstract— The characteristics of male upland bullies ( Gobiomorphus breviceps ) and their nest sites were examined in two New Zealand streams as possible determinants of male reproductive success. There was no association between male size, nest site characteristics (depth, distance to shore, river velocity, nest rock size), and male reproductive success. Similarly, the male's parasite load had no detectable influence on reproductive success. Multiple regression analysis revealed that no combination of factors could explain the wide variation in male reproductive success. It may be that the unpredictable nature of the stream habitats of bullies has favored reduced choosiness in females, which could lead to an absence of correlations between male and nest characteristics and reproductive success.     

悬链线理论及其应用研究 Ⅵ.单跨索道多荷重悬链线算法数学模型

从索道悬链线的标准线形出发 ,建立单跨架空索道在多荷重状态下悬链线算法的数学模型 ,在计算上采用牛顿迭代法来求解非线性方程组 ,能进行单跨索道多荷重的承载索精确设计     

流体压力对油气管道纵向稳定性的影响

建立了海洋立管的挠曲线微分方程，对两端固定约束的情况用无穷级数法求得其临界屈曲载荷计算式，并同时用能量法给出了其近似计算式。讨论了内外液压对管道纵向稳定性的影响，对平躺管道，外部液压的作用增加了管道的稳定性，内部液压的作用减小了其稳定性。计算结果可供管道设计时参考。     

浅谈临安实现农业现代化竹业仍需挑重担

文章回顾 了临安竹业在实现临安农村经济翻二番右面所起作用，分析了临安农业现代化主要指标与临安竹业关系，针对临安竹业存在问题和实现农业现代化需要，提出临安竹业进一步发展对策。     

我校5000米跑运动员马志安的短期训练分析

本通过对马志安的短期训练分析，提出了长距离跑各个阶段的训练特点，只有按照各个阶段的特点来训练才能创造好成绩，并着重指出快速力量在长距离跑中的重要性。     

湘潭湘江四大桥模型试验的加载方法研究

基于ANSYS软件建立了湘潭湘江四大桥有限元模型,通过有限元理论分析研究了桁架式拱肋组合受力特点,提出了关于桁架拱肋拱桥活载试验的一种活载加载方法.该方法将拱肋实腹段(拱脚)断面与桁架段断面分别按弯矩影响线与应力影响线布置活载.然后分别按传统方法和本文提出的新方法进行模型试验.理论与试验结果表明:新方法更能准确找出危险断面的最不利工况加载位置,这种新的活载布置方法也可为同类钢管混凝土桁架拱桥的试验提供参考.     

车辆动态称重系统误差产生机理

车辆动态称重系统广泛应用于治理超载超限运输,其称量精度与车辆通过计量平台时的运动状态有一定的关系。首先对运行车辆进行运动学分析,找出影响动态称重系统称量精度的主要运动形式,并以此为依据,得出车辆轴载称量原理,最后分析了车辆通过计量平台时的振动来源,以揭示称重系统误差产生机理。