A Model Combining Discrete Event System Simulation and Genetic Algorithm for Buffer Allocation in Unreliable Large Production Lines

To solve the difficulties in allocating buffers for unreliable large production lines, this paper investigated a model combining the genetic algorithm with the discrete event system simulation method. In the simulation method, times-to-failure of an unreliable large production line is assumed to follow exponential distribution, whereas times-to-repair and times-to-processing are set to follow an Erlang-k distribution. Using a genetic algorithm based on special position-based mapping means and elitist protection strategy, the buffer configuration of an auto-body welding line is optimized. The simulation of the optimized configuration shows that the performance of the production line, such as productivity and the main average utilization of the workstations, is much improved. This model can optimize the allocation of buffers for unreliable large production lines effectively.     

活性炭富集—GFAAS法测定乙烯气中的砷含量

提出一种乙烯气中砷的富集，消解方法，详细地考察了实验条件，用ＧＦＡＡＳ法对乙然气中砷含量进行了测定。相对标准偏差〈４．７％，测定结果与氢化物原子荧光法测定结果相吻合。     

热压工艺参数对n型和p型Bi2Te3基赝三元热电材料电学性能的影响

通过熔炼/研磨/热压方法制备了n型和p型赝三元Bi₂Te₃基的热压合 金样品，测量了由不同工艺参数(热压温度、热压压力)制备的样品Seebeck系数和电导率.分析了热压参数对热电性能产生的影响.特别是发现了增加热压压力和热压温度会使n型和p型热压样品的Seebeck系数和电导率都有所提高，这与单晶和取向晶体材料的Seebeck系数和电导率变化趋势相反的规律显然不同，其结果对热压样品的电学性能提高有积极的影响. 关键词： 热电材料 热压 Seebeck系数 工艺参数     

光学双稳态半导体激光器的理论分析

引入了正切函数作为非线性光－电流关系函数，借地速率方程，建立了光学双稳半导体激光器的理论模型。对器件本身进行了理论分析，讨论了器件的主要特性，给出了数值分析结果，提出了器件性能改进方法。     

论长期荷载下粘弹性薄壳的稳定性

在论文[10—12](注:本文的引文,下同)里,依据论文[9]里采用过的蠕变稳定的定义,通过受压柱形薄壳的例题,分析了粘弹性的解题特点。结果表明,对指定的构件就表面摄动而言,轴对称变形的稳定性范围可分成几个部分,而其中的每一部分的稳定性程度也有质的不同。     

毛泽东思想活的灵魂与邓小平“中国特色论”的精髓

本文通过对毛泽东思想活的灵魂与邓小平“中国特色论”的精髓的鲜明特质的分析，阐明两者所处的时代特点、历史作用和现实意义。     

环氧乙烷及其应用

环氧乙烷依其化学性質是最有利益的化合物之一。正如它的名称,环氧乙烷(又叫氧化乙烯)是乙烯的衍生物,在双鍵的位置連接着氧     

Scattering of an unpolarized Bessel beam by spheres

The scattering process of an unpolarized Bessel beam through spherical scatterers is investigated. We derive the analytical solutions of scattered fields of x-and y-polarized Bessel beams using a sphere, after which the dimensionless scattering function for an unpolarized Bessel beam is obtained. The dimensionless scattering function is applicable to spherical scatterers of any size on the beam axis or near it. Through numerical simulations, we demonstrate that extreme points exist in the direction or neighboring direction of the conical angle for spherical scatterers on the beam axis, whereas the existence of extreme points depends on the ratio between the spherical scatterers size and central spot size of the Bessel beam.     

河流古流量研究进展

河流古流速、流量的估算,可以反映出古河道的冲刷与沉积的演变过程．通过对古流量进行研究将为深入理解过去气候变化、讨论人类与环境变化的互动关系以及环境因素在文明形成中的作用都具有重要的意义．笔者对河流古流量研究状况进行了综述,多数学者主要用河相关系法、地貌-水力学法、泥沙粒径-水力学法、古水系法等对占流量进行估算,并指出了目前研究的不足和发展趋势,以利于研究者把握古流量研究现状,并推动其进一步探讨．