Product family formation and selection for reconfigurability using analytical network process

The paper develops a conceptual framework for product family formation towards reconfigurability through proposing a product-process reconfiguration link. Different decisive factors affecting product family formation and selection such as manufacturing requirements, market requirements, manufacturing cost and process reconfiguration are investigated. An analytical network process (ANP) model is proposed to incorporate all the outlined decisive factors and major criteria and elements influencing the product family formation and selection. As a consequence of the interactive nature of the product family selection problem, most of the children's’ elements within the same cluster and/ or different clusters are associated with each other. As a result, all the clusters are connected to each other (outer dependencies) as well as their connections to themselves (inner dependencies). The proposed ANP model is examined through a case study in a manufacturing company for validation. Synthesis judgments and sensitivity analysis are carried out for selecting the most appropriate product family along with analysing the influence of the selected critical elements.     

数值解析混合法分析永磁直线同步电机性能

针对数值法或解析法研究永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)性能时存在的不足,采用数值解析混合法研究PMLSM磁场,把电机的磁场划分区域,针对各区域特点分别采用纯解析法和数值法,气隙区包括永磁体无网格剖分,采用解析法获得此区的磁场解析表达式;初级齿槽区采用有限元法研究电枢不同励磁形式、齿槽及端部半填槽对磁场的影响.解析和有限元法通过两者的边界条件相耦合,建立并求解电机的磁场,获得空载电势与磁链参数,分析工作在SPWM-VI下PMLSM的动态性能,提出PMLSM空载电势实验的一种新方法,仿真和实验结果进行比较分析,验证了数值解析混合法分析PMLSM性能的正确性及快速性.     

长沙市轨道交通2号线场地地震地质灾害评价

根据查阅前人已有的基础资料,认真总结了工程场地范围内的地震活动性评价、地震危险性分析评估以及各站点的地震土层反应计算结果等资料,同时对长沙轨道交通2号线各站点及沿线工程场地的地震地质灾害进行了综合评价,得出工程场地的工程地震条件较好,整体稳定性较好,不存在威胁工程的严重地震地质灾害,工程场地基础经处理后适宜建设。     

Analytical models for the series resistance of selective emitters in silicon solar cells including the effect of busbars

A theoretical analysis of the power loss and series resistance of the front side emitter in silicon solar cells is presented. Existing 1D models (infinitely long finger) and 2D models (including the effect of busbars) of emitter series resistance contribution are extended to the case of selective emitters. The general case of different current densities for both emitters in the selective emitter scheme is considered in these extensions. The resulting models depend on the individual sheet resistances and current densities in both emitters and the device's overall grid geometry. The models are corroborated by finite element simulation of the potential in the emitter. An excellent agreement is found between the analytical models, and the simulations for a wide range of sheet resistances typically encountered in silicon solar cells. Grid simulations using the 2D model are applied to solar cells with selective emitters, where the width of the low‐resistive emitter was varied. The simulations demonstrate that the 2D model can explain the absolute change in fill factor observed in these cells. Copyright © 2013 John Wiley & Sons, Ltd.     

磁性高分子微球的制备及在分析化学中的应用进展

在总结近年来国内外有关磁性高分子微球研究成果的基础上,阐述了磁性高分子微球的结构类型、特点、目前的各种制备方法、袁征以及在分析化学领域的最新应用进展,指出了当前研究中需要解决的问题.     

航天器反作用轮扰动精细模型

为预测扰动对航天器产生的影响,并采取相应的控制方法和隔离系统,提出了基于反作用轮扰动实验模型的扰动精细模型,克服了解析建模高次谐波不准的缺点,精确地反映了反作用轮的扰动特点.利用这种方法可以有效地得到适用于仿真的系统方程.     

A dynamic problem on the edges of a mode I crack subjected to moving unit-step loads

By the theory of complex functions, a dynamic problem on the edges of a mode I crack subjected to moving unit-step loads are investigated. The Riemann-Hilbert problem is easily formulated by the ways of selfsimilar functions. The analytical solution obtained is rather simple and concise. After the solution was utilized by superposition theorem, the relevant solution on the case of arbitrary loading can be obtained.     

基于并行计算的三自由度并联机床动力学解析模型

基于运动学分析、凯恩动力学方程和数字-符号方法,建立了三自由度并联机床的动力学解析模型.将广义坐标、构件的质量和转动惯量处理为符号量.将动力学模型矩阵的推导问题转化为特定条件下运用运动学和动力学计算公式求解驱动力的问题,由计算机自动生成动力学模型矩阵中的各元素的实时代码.文中引入了一种新的标量矩阵与矢量矩阵的乘法运算,研究了广义坐标和构件的质量对驱动力的影响规律.构造了动力学解析模型的并行算法,节省了计算时间.给出了动力学模型矩阵元素的实时代码生成和驱动力矩与参数关系的具体数值实例.     

催化裂化催化剂形貌分析方法的建立

结合显微镜观察,通过分析毫米级颗粒、微米级Duke粒子及催化裂化催化剂,研究动态数字图像分析仪CamsizerX2分析颗粒形貌的合理准确性。考察分散方式、分散压力和记录颗粒数量因素的影响,建立了催化裂化催化剂球形貌分析方法。