论织物组织与丝线缩度的关系

本文通过对基元组织和新品种《涤春绸》组织经纬交织状况的研究,论述了不同织物组织对经线缩度的影响,求出了不同组织之间丝线理论屈曲长度的相互关系,进而从理论上阐明了《涤春绸》组织在实际生产中产生经向不同缩度的原因,并指出了解决问题的途径,对设计和生产具有一定的指导意义。     

关于体上的自共轭矩阵的注记

在文[1]、[2]的基础上,本注记证明了一般体上的自共轭矩阵的收缩定理,特征数≠2的体上的自共轭矩阵的GH对角化定理以及体上某些类型矩阵分解为自共轭矩阵乘积的相应结果,并得到了四元数体上的可中心化矩阵与可交换化矩阵的一种关系。     

砖混结构墙体裂缝设计防治措施

针对砌体结构较易出现的墙体裂缝问题进行了探讨，调查了裂缝产生的部位及裂缝形式，根据温度缝、收缩缝、沉降缝等各类裂缝的不同成因，结合工程设计和施工经验，提出了若干预防和控制措施，供实际工程参考。     

基于空间收缩的种群灭亡精英演化算法

对于多峰、非线性函数的最优化问题，提出一种新的基于空间收缩的种群灭亡精英演化算法（EEASCE)，以最优个体为中心收缩搜索空间，在新的收缩空间上重新初始化群体，提高群体的差异性，进行遗传操作，以避免算法对冗余空间的过多搜索，使得算法收敛到最优解，对标准测试函数的仿真表明，该算法具有精度高，稳健性强的优点。     

尼龙66原丝物理性能指标测试方法的改进

简述了目前中国神马集团尼龙 6 6浸胶帘子布生产过程中原丝纤度及原丝沸水收缩率指标的测试方法及存在的弊端 .通过对国内外同行业浸胶帘子布生产过程中原丝物理性能测试方法的比较及我公司对比测试 ,对原始数据统计分析后 ,提出了可行的改进意见     

砂型铸造中缩陷的预防

文章主要从缩陷的特征、种类及形成机理等方面讨论砂型铸造中的缩陷及其预防.     

On predicting abrupt contraction flows with differential and algebraic viscoelastic models

The numerical simulation of flows through a planar contraction at low Reynolds number is considered for Newtonian and for viscoelastic fluids. The recently proposed algebraic extra-stress model (AESM) derived from the differential constitutive equation for an Oldroyd-B fluid is extended to a Phan-Thien–Tanner fluid. The approach is based on the exact polynomial representation using a three-term tensor basis. It is also shown that the algebraic formulation reproduces exactly the extra-stress tensor components for pure shear and for pure elongation flow. A parameter based on the strain rate and the rotation rate tensors is presented to identify the regions of the flow where the AESM model produces exact results. A second-order numerical scheme accurate in time and space, based on the finite volume method using a staggered grid has been applied to solve the conservation and constitutive equations for the Newtonian and viscoelastic flows. The numerical simulations for the viscoelastic fluids have been done using the classical constitutive equations in a differential form and the algebraic extra-stress model. Excellent agreement between the extra-stress values is obtained with the two different approaches, showing the viability of AESM.     

元素电负性及其影响因素

本文介绍了八种电负性的标度方法及特点,并对电负性的影响因素进行了讨论。     

On a matrix cracking model using Coulomb’s friction law

A matrix cracking model is developed based upon Coulomb friction law instead of a constant frictional shear stress usually assumed in the matrix cracking analyses. A Lamé formulation incorporated with Coulomb friction law is adopted to solve the elastic states of fiber/matrix stress-transfer through a frictionally constrained interface in the slipping region and a modified shear lag model is applied to evaluate the elastic responses in the intact region. By using an energy balance approach, the critical stress for propagating a semi-infinite fiber-bridged crack in a unidirectional fiber reinforced composite is formulated in terms of the frictional coefficient rather than the frictional shear stress usually equated in the matrix cracking stress formulations. The critical stress for matrix cracking and the corresponding stress distributions calculated by the present Coulomb friction model will be compared with those predicted by the constant frictional shear stress models. The effect of Poisson contraction caused by stress redistribution between the fiber and matrix on the matrix cracking mechanics will be shown and discussed in the present analysis.