农村有线电视及广播故障维修问题研究

在我国现在有线电视越来越普及,乡镇有线电视接收也逐渐步入正轨。在世界科技迅猛发展的今天,作为科技发展较快的我国,乡镇有线电视的建设面临着投资金额较大、建设成果回收期较长等一系列问题。并且乡镇有线电视接收器的保养及外线故障的维修以及农村电视广播的维修业存在着一定问题。     

基于GA-PSO的多目标混流装配线排序研究

为求解生产调度中的多目标混流装配线排序问题,提出一种将遗传算法与粒子群算法相结合的混合算法——GA-PSO算法.为更好地评价个体,提出一种引入个体的Pareto分级和拥挤距离的适应度函数.针对标准PSO算法求解排序问题的不足,提出了一种将实数映射成离散值的方法.在算法的历次迭代中,早期通过遗传算法全局搜索优势扩大搜索范...     

煤基碳分子筛的制备及其研究进展

<正>碳分子筛(Carbon MolecularSieve,简称CMS)是近几十年发展起来的一种新型炭质吸附材料,它具有接近被吸附分子直径的狭缝型微孔(由1nm以下的微孔和少量大孔组成),孔隙发达且孔径分布均匀,能够把立体结构大小有差异的分子分离。本文,笔者简要介绍了CMS的结构、煤基碳分子筛的制备方法及国内外煤基碳分子筛的研究进展。     

中世纪西欧农奴制解体原因探析

中世纪西欧农奴制是西欧封建社会的一种经济形态,与自给自足的庄园经济相适应。伴随着社会经济的发展,农奴制日趋解体,农奴制的解体对资本主义经济的发展起到了促进作用。从社会经济产物、十字军东征、封建王权加强、封建立法及农奴们自身的斗争等方面探析其解体的原因有助于提高我们对这一问题的认识。     

有理依赖的食饵--捕食模型正周期解的存在性

研究了带时滞的有理依赖的食饵——捕食模型，借助迭合度理论建立了这个模型正周期解存在的充分条件．     

Σ2上关于Morse猜想的研究

对于一个动力系统,当它是度量传递的时,它一定是拓扑可迁的,但是,反命题却不一定成立.1946年和1973年,Morse先后两次提到拓扑可迁性能否推出度量传递性的问题.他猜想说对于解析或具有某种光滑性的系统,拓扑可迁性蕴含度量传递性.本文讨论在亏格数为2的紧致的可定向二维流形上,对于解析系统来说,猜想是成立的.     

远距离制备粒子的纠缠态

提出了一个远距离制备两粒子纠缠的方案，它是基于局域操作和经典通信实现的；借助于共生纠缠度讨论了纠缠操作对两粒子纠缠形式的影响；并将该方法推广到远距离制备多粒子的纠缠.     

Novel Plastic Encapsulation Holding Method for Automobile Glass Using Injection Molding Process

Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However, these materials cannot hold glass tightly, thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem, a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly, a pair of permanent magnets is introduced as energy source, followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold, which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding, the magnetic energy product and the magnetized filed distributions, and the re-checklng method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force, which not only protects glass but serf-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface, with no scratches and cracks on the glass and no slight glass movements in the mold cavity.     

面向产品族的敏捷配置研究

针对如何快速响应客户的需求,最大限度地节省配置成本,本文对面向产品族的敏捷配置进行了研究。首先,以产品设计平台为依托,从产品配置的角度出发提出了产品配置数据模型;然后,通过分析市场需求,建立产品族设计链,快速缩小设计空间;最后,以山地车为例进行说明。     

高瓦斯突出煤层工作面采空区瓦斯防治技术研究

针对高瓦斯突出煤层工作面上隅角瓦斯易超限的技术难题,以邹庄矿3204工作面为工程背景,利用数值模拟、理论分析、现场实测的研究方法,对采空区埋管及无埋管条件下工作面及采空区瓦斯分布规律进行了研究。结果表明:采空区埋管增加了上隅角瓦斯流动的通道,分流了采空区及工作面涌出的部分瓦斯,降低了上隅角及回风巷瓦斯浓度。据此,提出了采空区埋管为主,高位钻场抽采为辅的采空区瓦斯治理方案,现场实测验证了工作面高位钻场布置层位的合理性。工业性试验表明:采空区埋管为主,高位钻场抽采为辅的采空区瓦斯治理方案对实现采空区瓦斯治理具有积极意义。