便携式瓦斯检测仪管理系统的设计与实现

针对以人工登记为主的矿山便携式瓦斯检测仪发放和回收工作存在效率低下、工作流程繁琐及不利于管理和统计的问题,设计一种便携式瓦斯检测仪自动收发系统.该系统包括收发装置、服务器和Web客户端三部分,采用C-S和B-S共存的复合结构,以PHP作为开发语言,选用MySQL数据库.实际应用结果表明,该系统能够很好地完成仪表发放回收工作,便于科学的管理仪表,加快了矿山信息化和智能化的建设.     

时间触发以太网的分布式任务负载均衡分配方法

对于以时间触发以太网(time-triggered Ethernet,TTE)为互连基础设施的分布式综合化系统,通过将各个任务的物理拓扑、虚拟链路拓扑等多种设计约束属性转化定义为代价函数。提出了一种将信息处理和通信任务指派并映射到分布嵌入式资源的方法,使设计者能够利用TTE网络通信的时间确定性机制,统一地安排处理任务和通信任务。采用模拟退火算法启发式求解优化问题,保证网络节点处理和节点间通信的负载均衡性。通过一个TTE网络拓扑下任务分配的案例,采用软件仿真的形式说明这种方法的适用性。     

功能性建筑涂料照亮市场

功能性建筑涂料除了具备普通建筑涂料的装饰作用外，还能起到某种功能性作用。随着国民经济的快速发展，其应用也越来越普遍，可以预期，功能性建筑涂料的实用性，拓宽建筑涂料的应用范围。本文作者庚晋介绍了几种功能性建筑涂料的特点、主要用途、最新研究动态、施工方法、市场前景等。     

基于C#的Excel数据导入导出研究与实现

为了提高信息管理系统中数据导入导出操作的灵活性和通用性,本文详细介绍了在Visual Studio 2008使用C#语言、通过引用Office的COM组件技术,结合Microsoft SQL Server 2005实现了Excel数据导入到数据库以及数据库数据导出到Excel的设计思路和实现方法。实践证明该方法有较强的通用性和实用性。     

基于敲击声振法的风机叶片脱层检测系统设计

脱层是风机叶片的主要损伤形式,根据风电叶片的材料特性及外形特点,分析和研究了敲击声振检测原理和现场检测的可行性。叶片出现脱层时,缺陷处刚度下降,敲击应力持续时间增大。依据此检测原理,计算出合理的等效锤头质量,利用压电薄膜作为动态冲击力传感器进行了力锤的结构设计;利用FPGA设计了便携式检测仪,对敲击信号进行信息提取和处理,计算敲击力脉冲信号的宽度,具有结果图形显示和串行通信的功能。经过实验,验证了脉冲宽度与损伤深度的关系。     

Rheological behavior of two-phase polymer melts

Rheological behavior of dispersed two-phase polymer melts has been investigated by means of a capillary rheometer. The two-phase systems chosen for study were blends of two polymers: high-density polyethylene and polystyrene, which are incompatible in the molten state. In order to investigate the state of dispersion, photographs were taken of the microstructure of extrudate samples, showing that the polystyrene forms long fibers or droplets as a discrete phase dispersed in the polyethylene which forms a continuous phase. Measurements were made of the axial pressure distributions of the two-phase molten polymers flowing through circular tubes, which permit one, according to the theory advanced by Han, to determine viscous and elastic properties of the melts. Also measured was melt die swell ratio. It has been found from the two independent experimental techniques that there exist a maximum and/or minimum elastic property at a certain blending ratio, and that the elastic property decreases first with L/D ratio of a capillary and then levels off.     

四种杀菌剂对枸杞黑果病的防治效果

枸杞黑果病是枸杞产区的主要病害．发病后造成黑花、黑蕾和黑果，使枸杞产量降低，品质变劣。为探明四种杀菌剂对枸杞黑果病的防治效果及最佳剂量，2003年对下述四种杀菌剂进行了田间药效对比试验，调查防效结果如下：20％三苯基醋酸锡WP450～281g／hm^2(以有效成分计，下同)，20％氟硅唑EC21．08g／hm^21．5％噻霉酮EW16、88～21．08g／hm^2、40％氟硅唑EC450g／hm^2和70％甲基托布津WP787．5g/hm^2对枸杞黑果病防效均在88．25％以上。经LSD检验各处理间防效无显著差异。     

Interrelationship of the baric index for the normal burning velocity of gas—Air mixtures and the kinetics of trimolecular reactions in a flame front

Through numerical simulation of flame propagation through a methane- and hydrogen-air mixture, with consideration given to the transfer and chemical reactions, we have investigated the relationship between the kinetics of trimolecular reactions and the baric index of the normal burning velocity. It has been demonstrated that the lower the constants of the trimolecular reaction rates, the higher the magnitude of the baric index. In the case of methane the baric index, although it grows, it nevertheless remains negative, while in the case of hydrogen this index changes sign.Balashikha. Translated from Fizika Goreniya i Vzryva, No. 2, pp. 46–49, March–April, 1991.