载流导体的二维温度场的分析

为分析机电设备导体中电流引起的热分布问题,建立了机电设备的简化有限元模型,对导体进行了自适应网格划分,采用有限元方法求解热导微分方程,得到导体中热分布情况,可以估算导体的形状和尺寸,为机电设备选择合适的导体提供了一种有效的设计方法。     

钓鱼网站的鉴别方法与防范策略研究

文章从钓鱼网站的种类和传播途径入手,重点分析了钓鱼网站的鉴别方法和防范措施,最后指出了打击钓鱼网站的难度.     

叶片类零件检测方法的试验研究

研究了交流电磁场信号对叶片裂纹影响的方式和规律,分析和找出了缺陷与交流电磁场信号响应特征之间的关系,提出了叶片表面采用交流电磁场检测技术的原理、方法.通过采用交流电磁场检测技术检测证实,在工程检测中有一定的实际意义.     

连续刚构箱梁剪力滞效应分析

以靖远黄河大桥这一五跨连续刚构箱梁桥为工程背景,运用当量截面法计算靖远桥的剪力滞系数。分析其简化计算,将结果与ANSYS分析结果进行比较。     

仲丁醇含量对正丁烯直接水合法制仲丁醇的影响

研究了正丁烯直接水合法制仲丁醇工艺中原料水中仲丁醇含量对反应的影响.当原料水中含有少量仲丁醇时(约0.9%时),其对水合反应过程的转化率影响不大;原料水中含有少量仲丁醇时,反应过程的稳定性比较好.当水合反应的原料水中仲丁醇浓度增大时(原料水中仲丁醇浓度为2.0%左右时),反应过程的转化率明显下降.当水合反应的原料水中仲丁醇含量进一步增大时,反应过程的转化率下降明显,但呈非线性变化.     

复合材料蜂窝夹层结构计算的一般方法和进展

本文对目前蜂窝夹层结构有限元分析的方法进行旭纳；对每一种计算模型中所包含的假设作一讨论；指出其适用范围，供设计和强度计算时参考。     

On learning and development, Piagetian style: I. A reply to Lefebvre-Pinard.

Examines the equilibration theory of Piaget (learning vs development, stage transitions) to make more explicit the methodological foundations of B. Inhelder et al (1974). In this connection, the "problem-solving" learning method used by these authors is analyzed by means of the new concept of "learning loops." Similarly, the successful equilibration learning method used by M. Lefebvre and A. Pinard (1974) is analyzed and shown to involve executive facilitation and chunking (coordination) of 2 crucial schemes. A process-structural model of conservation acquisition previously developed by the present author, and its empirical tests by R. Case (1975) and by G. M. Parkinson (1975), are used to illustrate and to empirically support the process-structural differences theoretically found between these 2 equilibration methods. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一种16QAM调制实现技术的研究

讨论了16QAM调制时应用不同类型和参数的滤波器对系统性能的影响．针对16QAM的特点，采用了存储波形累加求和法来代替一般的滤波成形，提高了调制速度．并利用其相位对称的特点将波形存储表压缩为原容量的1／4，有效地节约了存储空间．     

Nodal DG-FEM solution of high-order Boussinesq-type equations

A discontinuous Galerkin finite-element method (DG-FEM) solution to a set of high-order Boussinesq-type equations for modelling highly nonlinear and dispersive water waves in one horizontal dimension is presented. The continuous equations are discretized using nodal polynomial basis functions of arbitrary order in space on each element of an unstructured computational domain. A fourth-order explicit Runge-Kutta scheme is used to advance the solution in time. Methods for introducing artificial damping to control mild nonlinear instabilities are also discussed. The accuracy and convergence of the model with both h (grid size) and p (order) refinement are confirmed for the linearized equations, and calculations are provided for two nonlinear test cases in one horizontal dimension: harmonic generation over a submerged bar, and reflection of a steep solitary wave from a vertical wall. Test cases for two horizontal dimensions will be considered in future work.     

Meshless local Petrov-Galerkin method for continuously nonhomogeneous linear viscoelastic solids

A meshless method based on the local Petrov-Galerkin approach is proposed for the solution of quasi-static and transient dynamic problems in two-dimensional (2-D) nonhomogeneous linear viscoelastic media. A unit step function is used as the test functions in the local weak form. It is leading to local boundary integral equations (LBIEs) involving only a domain-integral in the case of transient dynamic problems. The correspondence principle is applied to such nonhomogeneous linear viscoelastic solids where relaxation moduli are separable in space and time variables. Then, the LBIEs are formulated for the Laplace-transformed viscoelastic problem. The analyzed domain is covered by small subdomains with a simple geometry such as circles in 2-D problems. The moving least squares (MLS) method is used for approximation of physical quantities in LBIEs.