Improved hydrogen desorption properties of ammonia borane by Ni-modified metal-organic frameworks

Ammonia borane (AB) has attracted intensive study because of its low molecular weight and abnormally high gravimetric hydrogen capacity. However, the slow kinetics, irreversibility, and formation of volatile materials (borazine and ammonia) of AB limit its practical application. In this paper, new strategies by doping AB in metal-organic framework MIL-101 (denoted as AB/MIL-101) or in Ni modified MIL-101 (denoted as AB/Ni@MIL-101) are developed for hydrogen storage. In AB/MIL-101 samples, dehydrogenation did not present any induction period and undesirable by-product borazine, and decomposition thermodynamics and kinetics are improved. For AB/Ni@MIL-101, the peak temperature of AB dehydrogenation was shifted to 75 °C, which is the first report of such a big decrease (40 °C) in the decomposition temperature of AB. Furthermore, borazine and ammonia emissions that are harmful for proton exchange membrane fuel cells, were not detected. The interaction between AB and MIL-101 is discussed based on both theoretical calculations and experiments. Results show that Cr-N and B-O bonds have generated in AB/MIL-101 nanocomposites, and the decomposition mechanism of AB has changed.     

双啮合弦线转子泵的设计及流量分析

为了降低弦线转子泵的流量脉动率和提高转子的面积利用系数，提出具有两对转子的双啮合弦线转子泵。分析转子径距比对弦线转子泵脉动率和转子面积利用系数的影响；探究双啮合弦线转子泵流量脉动率与两对转子之间的差动角大小的关系，得出了当差动角〖BF〗α=π/(2z)〖BFQ〗时，双啮合弦线转子泵的脉动率为0；且此时通过增大转子径距比可提高转子面积利用系数，使转子面积利用系数由原来的245%提高到451%。研究结果表明：双啮合弦线转子泵具有转子面积利用系数高、无流量脉动的特点。     

扩张型等离子体热壁反应装置及冶炼粉矿的研究

为了适应等离子体反应装置冶炼矿的需要，研制出扩张型等离子体热壁反应装置，用此反应装置进行了分解锆石和碳还原钛铁矿的试验。结果表明，此装置结构简单，输送矿速度快、传热效果好。     

加纳布维水电站调相运行系统设计简介

从水轮发电机组调相、压水系统的设计计算、控制流程、止漏环冷却、补气等环节对加纳布维水电站调相系统设计进行详细介绍,为其它水电站调相运行系统的设计提供参考。     

Outage probability analysis for superposition coded symmetric relaying

Superposition coded symmetric relaying is a bandwidth-efficient cooperative scheme where each source node simultaneously transmits both its own "local" packet and "relay" packet that originated at its partner by adding the modulated local and relay signals in Euclidean space. This paper investigates the power allocation and outage probability of a superposition coded symmetric relaying system with finite-constellation signaling. We first derive the mutual information (MI) metrics for the system. The derived MI metrics consist of two parts: one represents the MI conveyed by the modulated signal corresponding to its own data, and the other represents the MI conveyed by the modulated signal corresponding to its partner’s data. Using MI based effective signal-to-noise ratio mapping technique, we attain expressions for the outage probability. Furthermore, we discuss power allocation policies that minimize the outage probability. Simulation results are presented to verify the correctness of the outage probability analysis and the benefits of the power allocation.     

激光跟踪仪在汽车车身检测和分析中的应用

本文探讨了激光跟踪仪的使用特点以及近年来最新发展的6D测量技术，并基于此提出了车间现场环境中车身的检测和分析方案，及时、快速的发现和解决车身零件制造，尺寸分析等问题，提高汽车车身测量效率和生产质量。     

环境为热浴的开放量子系统模型的研究

基于具有non-Markovian特性的关于量子系统约化密度矩阵的精确系统动力学方程，分别根据方程所具有的非封闭、不等时、积分微分方程的特性，通过Born逼近和Markov逼近得到关于量子系统约化密度矩阵的封闭、等时和微分的Markovian主方程；逐一分析了Markovian主方程的Lindblad形式、具有方便检验正定性的GKS表达形式、针对单量子位系统的Bloch球表达形式和无需明确的环境信息也能对开放系统进行描述的Kraus表达形式；分析并比较了能去除系统动力学方程non-Markovian特性的4种Markov逼近方法以及其他四种特定情形下常见的Markovian主方程；对于不适用于Markov逼近的情形，分析了能满足开放量子系统动力学对于系统状态要求的post-Markovian主方程；当热浴与量子系统发生能量交换，且热浴与量子系统组成的封闭系统能量守恒时，给出了热浴状态不恒定时开放量子系统的动力学方程，并通过Markov逼近得到Markovian主方程。     

全球家居创新GIA奖2010-2011年度颁奖盛典

去年3月,笔者曾有幸出席了2009-2010年度GIA(Global Innovator Awards Dinner)颁奖典礼及晚宴.如果说那是以中国专业媒体嘉宾的身份,抑或是作为见习评委出席盛典的话,那么时隔一年之后的2011年3月6日晚上,就是名正言顺地作为国际评委出席了2010-2011年度GIA的颁奖盛典,见证...     

旋挖钻机主卷扬新型卷筒研究与应用

国产旋挖钻机主卷扬机构钢丝绳寿命偏短是行业的一个共性问题,也是一个急需解决的难题。影响钢丝绳寿命的因素多,工作时受力情况比较复杂,钢丝绳排绳与磨损目前没有权威理论可循。本文从排绳机理和卷筒结构系统研究,通过试验及数据分析,找出主要影响因素,提出了有较高实用价值的新型主卷扬改进的总体思路和方案,该新型主卷扬解决方案已运用于中联重科多个型号旋挖钻机上。