新型碳纳米复合材料实现太阳能化学储热

<正>开发新型太阳能热存储材料已成为探索太阳能高效利用的重要基础。近日,天津大学材料学院封伟教授带领的团队,通过化学结构设计,制备了具有高效光伏化学储热特性的偶氮苯/石墨烯复合材料,克服了传统光伏储热材料与技术存在存储密度低和装置体积庞大等局限性,为实现高密度、长效循环的太阳能储热提供了可能。该成果日前刊发在自然(Nature)出版集团旗下期刊《科学报告》(Scientific Reports)上。,,     

气相色谱-质谱-选择离子存储法检测皮革和纺织品中的禁用偶氮染料

采用气相色谱-质谱-选择离子存储法,结合保留时间、特征离子的相对丰度比、谱库检索信息、峰面积对皮革和纺织品中的禁用偶氮染料进行定性、定量分析。在选择离子存储模式下,各种偶氮染料的浓度在5～100μg/mL范围内与色谱峰面积呈良好的线性关系,相关系数大于0.9903。对于大部分芳香胺3种浓度水平的加标回收率为69.8%～94.3%,检出限为0.005～2.446μg/mL(S/N=3),测定结果的相对标准偏差小于13%(n=6)。该方法满足禁用偶氮染料的分析要求。     

手性分子光开关研究进展

介绍了近年来发展起来的不同类型的手性光开关分子, 如手性螺烯、偶氮苯、二芳基乙烯、螺吡喃、联二萘、俘精酸酐、胆红素-IIIα, 手性光致变色聚合物等; 讨论了分子手性光开关材料特殊的光致异构性质, 综述了该材料在信息存储等应用方面的研究状况, 并展望了手性光开关材料的研究前景.     

新型全息用光致聚合物的研究

研制了一种新型全息用光致聚合物材料,其成膜树脂为胺固化环氧体系,全息记录组分为光引发自由基聚合体系.用新合成的高效光敏染料DEAMC做光敏剂,通过配方调整,制备了一系列的样片,以457 nm的蓝光为记录光,632.8 nm的红光为探针光,研究了样片的衍射效率、灵敏度、折射率调制度等全息性能.结果表明,通过调整材料的配方组成、各组分的含量及样片的膜厚等因素,可以优化样片的全息性能.对样片的信噪比损失(LSNR)测试结果表明,在全息存储的曝光量范围内对样片曝光引起的图像信噪比损失仅有0.40 dB,说明样片的光学质量高,在全息存储上将具有很好的应用前景.     

Simulation Analysis of the Optimal Storage Resource Alloction for Large HENP Databases

Large High Energy and Nuclear Physics(HENP)databases are commonly stored on robotic tape systems because of cost considerations.Later,selected subsets of the data are cached into disk caches for analysis or data mining.Because of the relatively long time to mount,seek,and read a tape,it is important to minimize the number of times that data is cached into disk.Having too little disk cache will force files to be removed from disk prematurely,thus reducing the potential of their sharing with other users .Similarly,having too few tape drives will not make good use of a large disk cache,as the throughput from the tape system will form the bottleneck.Balancing the tape and disk resources is dependent on the patterns of the requests to the data.In this paper,we describe a simulation that characterizes such a system in terms of the rsources and the request patterns.We learn from the simulation which parameters affect the performance of the system the most.We also observe from the simulation that,there is a point beyond which it is not worth investing in additional resources as the benefit is too marginal.We call this point the “point-of -no-benefit“(or PNB),and show that using this concept we can more easily discover the relationship of various parameters to the performance of the system.     

Electrochemical hydrogen storage properties of melt-spun Ti0.9Zr0.1V0.2Ni1.5La0.5 alloy

The Ti_0.9Zr_0.1V_0.2Ni_1.5La_0.5 alloy samples were synthesized by melt-spinning technique at the different wheel velocity (cooling rate), and the structure and electrochemical hydrogen storage properties were investigated. The result indicated that the structure of the melt-spun ribbons mainly contains C14 Laves phase and V-based solid solution phase. The discharge capacity, cyclic stability, high-rate discharge ability and electrochemical kinetic of the alloy electrodes are correlated with the cooling rate (wheel velocity), and the maximum discharge capacity is over 200 mA·h/g at the wheel velocity of 20 m/s.     

轻质建筑中定形相变内隔墙板冬季应用效果研究

现代轻质建筑热容较小,窗墙比较大,冬季在利用透射太阳辐射采暖的同时易造成室内温度波动过大。本文提出将定形相变蓄能板安装在建筑内隔墙表面,以增加建筑热容,减小室温波动。采用经实验验证程序,模拟分析了相变板热物性、表面换热系数和用量对冬季室内温度波动的影响,给出了北京地区相变内隔墙房间的设计原则。