Design of the low power wake-up receiver for internet of things communication

A wake-up receiver with high energy efficiency and low power consumption is proposed for solving the power consuming problems of wireless nodes communication in the Internet of Things. The proposed wake-up receiver based on the wake-up mechanism can effectively schedule the network nodes communication, and use the simple envelope detection structure to achieve frequency down-conversion, which can flexibly manage energy and reduce power consumption. Based on UMC 65nm CMOS process technology, the wake-up receiver is designed and simulated. The results show that it can achieve S₁₁ of -21dBm and a sensitivity of -75dBm at a data rate of 1Mb/s, when operating at the central frequency of 780MHz and input signal adopting an on-off keying (OOK) modulation, and the power consumption is 82μW at 1.2V voltage supply.     

小型水库斜卧涵铸铁放水口设计与应用

文章介绍了斜卧涵铸铁放水口的设计内容,阐述了其在运行管理中的优点。     

浅谈矿场原油含盐量化验的创新方法

现行含盐量化验方法存在着耗时长、有安全隐患、操作不慎易导致试验失败等不足。基于矿场含盐量化验的原理,通过理论分析与对照试验检验,对现行含盐量化验方法进行改进,提出了一种化验原油含盐量的创新方法。该方法在确保化验结果准确的前提下,可提高化验效率,保障人身安全,降低工作强度,满足矿场对含盐量资料需求,提高含盐量资料的全准率。     

一种基于改进的多值因果图的近似推理

针对因果图的精确推理是NP难的,提出寻找近似的推理算法。根据以往文献中近似推理的原理,通过一种可能性比值,找到转化后的连接事件概率。该近似推理保证了多值因果图在推理过程中概率的归一性,最后用于实例得出的结果满足概率论知识且符合实际。     

基于脱钩模型的新疆碳排放与经济增长的关系研究

在共建丝绸之路经济带以及生态文明的大背景下,新疆作为丝路经济带的核心区与中国西部重要的桥头堡,其经济发展的速度与效益值得关注。尤其新疆是我国重要的能源资源储备区,如何协调好能源开发过程中的碳排放与经济增长之间的关系,是当前摆在我们眼前的一大课题。本文旨在通过脱钩模型分析新疆碳排放与经济增长之间的关系,得出新疆碳排放与经济增长总体上呈现弱脱钩的结论,据此分析弱脱钩状态产生的原因,并提出了有针对性的对策建议,以期促进新疆经济能更好的适应经济新常态。     

传统刺绣工艺在现代服装设计中的时尚化体现

对传统刺绣在当代时尚社会的发展进行了初步的研究,从刺绣本身的材质、图案题材、针法到刺绣工艺手法的结合创新,进行了分析,总结出传统刺绣的时尚性演变与发展,旨在对现有的刺绣情况进行总结,丰富设计手法,将传统刺绣的继承与发展落到实处。     

Simple Preparation of Crystal Co3（BTC）2·12H2O and Its Catalytic Activity in CO Oxidation Reaction

Crystalline metal-organic framework cobalt(Ⅱ) benzenetricarboxylate Co3(BTC)2?12H2O(MOF-Co) has been prepared using solvothermal method. The reaction of cobalt(Ⅱ) nitrate and 1,3,5-benzenetricarboxylic(BTC) acid in a mixed solution of N,N-dimethylformamide(DMF)/C2H5OH/H2O(1:1:1, ν/ν) at low temperature for short reaction times produced this crystalline compound. Compared with traditional hydrothermal method, a mixed solution method for the synthesis of crystalline metal complex was found to be highly efficient. After water molecules were removed from this metal complex, its exposed nodes served as active sites. When this MOF-Co was employed in the oxidation of CO, it showed good catalytic properties causing 100% conversion of CO to CO2 at low temperature of 160 ℃.     

Global optimization for ducted coaxial-rotors aircraft based on Kriging model and improved particle swarm optimization algorithm

To improve the operational efficiency of global optimization in engineering, Kriging model was established to simplify the mathematical model for calculations. Ducted coaxial-rotors aircraft was taken as an example and Fluent software was applied to the virtual prototype simulations. Through simulation sample points, the total lift of the ducted coaxial-rotors aircraft was obtained. The Kriging model was then constructed, and the function was fitted. Improved particle swarm optimization(PSO) was also utilized for the global optimization of the Kriging model of the ducted coaxial-rotors aircraft for the determination of optimized global coordinates. Finally, the optimized results were simulated by Fluent. The results show that the Kriging model and the improved PSO algorithm significantly improve the lift performance of ducted coaxial-rotors aircraft and computer operational efficiency.     

电控柴油机分缸均衡控制算法及试验

柴油机各个气缸的进气量、喷油量、燃烧等存在差异,导致气缸间存在做功差异,直接影响柴油机转速的平稳性以及排放性能等。针对位置式电控柴油机,采用PI闭环控制,通过瞬时转速信号识别并计算各缸的工作差异,利用分缸均衡控制算法对油量进行补偿修正。试验结果显示低转速稳态工况转速波动由7 r/min降至3 r/min,各缸工作不均匀度由±5 r/min降至±2 r/min,在瞬态过程和高转速3 400 r/min时该算法仍然适用有效。     

基于改进Kendall-f算法的发电机定子温度分析

在线监测发电机定子温度可有效发现定子部分过热性故障,如何从检测的温度数据中提取反映定子故障预警的信息是目前国内外研究的热点。该文采用可变窗改进Kendall-f算法处理监测温度数据,提取其变化趋势特征信息;采用偏度分析提取监测温度异常值,从而正确诊断定子过热性故障,仿真分析及实验结果表明该方法有效提高了定子温度监测与预警的准确率。