粮食温度无线检测系统设计

介绍粮库房式仓粮食温度检测系统和无线数据传输方法,单片机与无线收发模块nRF401的硬件接口电路和软件设计,点对多点无线通信协议.     

基于突变理论的采空区顶板安全厚度多因素预测模型

确定采空区顶板安全厚度对保证矿山作业安全具有重要意义。本文采用有限差分软件FLAC3D,基于尖点突变理论和强度折减法研究西石门铁矿采空区顶板安全系数与其厚度的函数关系,建立了顶板安全厚度判断方法。在此基础上,通过单因素试验研究了采空区纵深、跨度、高度、顶板粘聚力与抗拉强度对采空区顶板安全厚度的影响,结果表明：纵深、跨度、顶板粘聚力、抗拉强度与顶板安全厚度之间分别呈现线性、非线性正相关、非线性负相关、非线性负相关的变化关系;高度对顶板安全厚度的影响非常小。并建立了综合考虑采空区纵深、跨度、顶板粘聚力与抗拉强度4种因素的采空区顶板安全厚度预测模型,为确定采空区顶板安全厚度提供了一种新的研究方法。模型预测结果与某硫铁矿瞬变电磁勘探结果相吻合,验证了预测模型方法的科学性和有效性。     

预应力垂直锚补偿重力式结构在闹市窄地基坑围护中的应用

介绍预应力垂直锚的施工及其施工要点，相对于钭拉锚而言，垂直锚占地极为有限，因此，在闹市窄地基坑围护中应用预应力垂直锚补偿重力式结构，具有其独特的优势。     

复合型土钉墙的非线性有限元分析

复合型土钉墙是近年来在沿海软土地区出现的一种新型基坑围护结构 ,已得到广泛应用。建立并采用了带转动自由度的Goodman单元 ,对其进行的非线性有限元分析 ,通过与工程实例的对比检验了这一方法的合理性。     

灵活选用电气控制柜导线配线规格

根据电磁学原理，当电流流过导线时，载流子在导线中将趋于导线表层，即产生“趋肤效应”，从而降低了导线的有效使用率，本文根据多年的实践经验提出的“组合导线工艺”，可提高导线的有效使用率。     

Thermal Transport in Conductive Polymer–Based Materials

The demand for flexible conductive materials has motivated many recent studies on conductive polymer–based materials. However, the thermal conductivity of conductive polymers is relatively low, which may lead to serious heat dissipation problems for device applications. This review provides a summary of the fundamental principles for thermal transport in conductive polymers and their composites, and recent advancements in regulating their thermal conductivity. The thermal transport mechanisms in conductive polymer–based materials and up‐to‐date experimental approaches for measuring thermal conductivity are first summarized. Effective approaches for the regulation of thermal conductivity are then discussed. Finally, thermal‐related applications and future perspectives are given for conductive polymers and their composites.     

空间环境下磁性液体润滑/密封初探

磁性液体(磁流体/磁流变液)作为一种新型磁控智能材料,兼顾液体的流动性及固体磁性材料的磁响应特性,在外磁场作用下可实现二者间的可逆性转换。磁性液体润滑密封因其零泄漏、自修复等优良特性受到广泛关注,特别是近年来在航天装备中的应用研究。为探讨磁性液体在航天装备中的应用,从恶劣的宇宙环境出发,分析地外空间装备研发所面临的严峻环境挑战,对高真空、高辐射、高低温热循环三大主要问题进行针对性分析,探讨磁性液体用于航天装备润滑/密封的可行性,总结相关磁性液体极端工况润滑/密封技术的进展和局限性,并提出未来研究中亟待解决的重要科学问题。     

电控柴油机在线故障诊断系统实用简单计算方法研究

本文使用简单实用C＋＋算法及基本数学理论进行快速、实用电控柴油机在线故障诊断的研究。首先,进行了特有的故障码设计,按照故障码的原理,对故障进行了分类。接着,充分运用故障码编制形成的框架,对基本故障的诊断算法进行了编制。然后,对多参数故障及复杂故障进行了算法设计。最后,为提高故障库的扩展功能,设计了“未知故障”处理功能。另外,进行了软件可靠性的研究。通过模拟实验结果表明：系统设计合理,工作可靠,达到了预期的目标,证明故障论断实用简单算法的可行性。     

Magnetic Properties of La1-xSrxCoO3 (0≤x≤0.5)

The measurements of temperature dependence of the magnetic susceptibility of La1-xSrxCoO3 perovskite oxides at different Sr doping (0≤x≤0.5) and annealing temperature were presented. For the sample with x=0.1, a shoulder was observed around 150 K, and a peak which is one feature of spin glass appeared around 50 K in the curve of susceptibility versus temperature. The high-temperature(250～420 K)susceptibility fits well with Curie-Weiss law for all samples. Weiss constant and effective magnetic moment were determined and their variations with Sr doping and oxygen annealing condition were obtained. The Weiss constant increases monotonously with Sr content for x>0.2. The values of effective moments were interpreted with the spin state of cobalt ions. Studies on the susceptibilities of the samples with x=0.2 under different preparation temperatures and annealing temperatures show that the rising of sintering temperature and annealing temperature will increase the para-ferromagnetic transition temperature, and reduce the effective moment to normal value. Our result shows that both Co3 and Co4 ions should be in IS state after annealing and the oxygen annealing causes the transition of Co3 spin state from HS to IS.     

架空电缆在10 kV线路应用中的探讨

通过对10kV架空绝缘导线(以下简称架空电缆)性能分析，指出架空电缆在线路运行中的可靠性、经济性以及架设施工、维修便利等方面都优于裸导线。为了进一步科学应用架空电缆，针对一些容易发生的问题，提出了相应的防止措施，重点介绍了国内外架空电缆的防雷技术和咸宁地区的防雷特点。