钢筋混凝土梁有效高度不定性成因与控制

混凝土梁的有效高度直接影响到构件的截面承载能力,在设计、施工过程中处理不当,将直接导致质量事故的发生,必须引起工程界的重视。探讨了混凝土梁有效高度的不定性成因,并提出了控制截面有效高度的若干对策。     

Hierarchical closed form solutions for plates bent by localized transverse loadings

3D and 2D closed form plate models are here applied to static analysis of simply supported square isotropic plates. 2D theories are hierarchically classified on the basis of the accuracy of the displacements and stresses obtained by comparison to the 3D exact results that could be assumed by the reader as benchmark for further analyses. Attention is mainly paid on localized loading conditions, that is, piecewise constant load. Also bi-sinusoidal and uniformly distributed loadings are taken into account. All of those configurations are considered in order to investigate the behavior of the 2D models in the case of continu- ous/uncontinuous, centric or off-centric loading conditions. The ratio between the side length a and the plate thickness h has been assumed as analysis parameter. Higher order 2D models yield accurate results for any considered load condition in the case of moderately thick plates, a/h=10. In the case of thick plates, a/h=5, and continuous/uncontinuous centric loading conditions high accuracy is also obtained. For the considered off-centric load condition and thick plates good results are provided for some output quantities. A better solution could be achieved by simply increasing the polynomial approximation order of the axiomatic 2D displacement field.     

保险定价中的安全附加费

本文用效用理论阐释了保险定价中的安全附加费存在的合理性、可行性和应该满足的条件。并且解释了再保险可以降低安全附加费,从而降低保险商品的定价。     

Nonlinear analytical solution for one-dimensional consolidation of soft soil under cyclic loading

INTRODUCTION Conventional consolidation analysis based on Terzaghi’s one-dimensional theory neglects the non-linearity of soil for the sake of mathematical expediency, which is considered to be one of the theory’s shortcomings. Many researchers have pro-posed one-dimensional (1D) consolidation models where the coefficient of volume compressibility mv, coefficient of permeability kv, and coefficient of consolidation cv, vary with either depth or time. Schiffman (1958), Davis and Raymon…     

因子分析在学生成绩分析中的应用

用因子分析对我系01级学生各门课程成绩进行分析,寻找出学生成绩背后隐藏的潜在变量,并将因子得分排序与传统排序进行比较,得到了一些有意义的结果．     

随机荷载作用下梁的弹塑性极限分析

讨论了随机荷载特性与结构弹塑性极限分析的基本假设，基于机动法和静力法，对矩形截面梁的随机弹塑性极限分析进行了研究，其结果对结构随机优化设计具有重要意义。     

TiO2光催化剂在膨润土上的负载化及载钛量测定

用离子交换法在膨润土上负载TiO2，用分光光度法测定了负载型二氧化钛光催化剂中的钛含量，考察了不同浓度的Ca^2 、Mg^2 、Fe^3 、Al^3 杂质离子和不同显色酸度对载钛量测定的影响．研究结果显示，最佳的酸度为1．5M，最佳的负载温度为45℃，最佳的负载时间为3h。     

Analysis on Dynamic Response of Hard-Soft-Hard Sandwich Panel Under Blast Loading

Surface contact explosion experiments have been performed for the study of dynamic response of the hard-soft-hard sandwich panel under blast loading. Experimental results have shown that there are four damage modes, including explosion cratering, scabbing of the backside, radial cracking induced failure and circumferential cracking induced failure. It also illustrates that the foam material sandwiched in the multi-layered media has an important effect on damage patterns. The phenomena encountered have been analyzed by the calculation with ALE method. Meanwhile, the optimal analysis of foam material thickness and position in the sandwich panel were performed in terms of experimental and numerical analysis. The proper thickness proportion of the soft layer is about 20% to the thickness of sandwich panel and the thickness of the upper hard layer and lower hard layer is in the ratio of 7 to 3 under the condition in this paper when the total thickness of soft layer remains constant.     

Evaluation of blast-resistant performance predicted by damaged plasticity model for concrete

In order to evaluate the capacity of reinforced concrete (RC) structures subjected to blast loadings,the damaged plasticity model for concrete was used in the analysis of the dynamic responses of blast-loaded RC structures,and all three failure modes were numerically simulated by the finite element software ABAQUS.Simulation results agree with the experimental observations.It is demonstrated that the damaged plasticity model for concrete in the finite element software ABAQUS can predict dynamic responses and typical flexure,flexure-shear and direct shear failure modes of the blast-loaded RC structures.     

"学分银行"的信贷运行机理解读

"学分银行"具有作为银行的存储、信贷、兑换的基本功能,可从事诸如存分(学分)、贷分(学分)和学分兑换(转换)等基本业务活动.其最高境界是学分通兑,但必须经历从学分认证到互认到通兑的循序深化、通畅的过程.这有赖于诸如学分绩点效应、"学分银行"的级别分类、"学分银行"间的学分通兑系数以及学分标准的制定等一系列难题的合理解决.