Improved thermodynamic property fields of LiBr–H2O solution

This article presents a thermodynamically consistent set of specific enthalpy, entropy, and heat capacity fields for LiBr–H₂O solution. The temperatures span from 0 to 190°C, while the concentrations span from 0 to 75 wt%. The work is based on the empirical inputs of Dühring's gradient and intercept, specific heat capacity data at a reference concentration of 50 wt% and density data. These properties have been evaluated using most of the experimental data available in the literature. The present approach circumvents the issue of negative dew point at low temperatures and high concentrations. The information provided in this article could be useful for designers of absorption chillers.     

优化系统,废热蒸汽资源化

本文介绍了一个将废热利用与改善环境相结合，成功实施的案例。该项目既提高了企业的经济效益，又改善了环境。通过案例实施技术、经济和环境效益的分析表明：废热利用和改善环境相结合的技术是一种最佳的能量回收技术，应在企业大力推广。     

Preparation and properties of the heteropolyoxometalates of large organic cation with molybdotungstosilicic acids

Some new heteropolyoxometalates of large organic cations with molybdotungstosilicic acids （general formula： （CTMA）4SiMoxW12-xO40·mH2O·nDMF, x=0,2,4,6,8,10,12） were prepared by the reaction of cetyltrimethylammonium bromide （CTMAB,C16H33N（CH3）3Br） with H4SiMoxW12-xO40（x=0,2,4,6,8,10,12） in aqueous solution and recrystallization in DMF, and characterized by elemental analysis, IR spectra,TG- DTA and XRD techniques. The IR spectrum confirms the presence of Keggin structure and organic cations in these compounds, and it is indicated that the stretching vibration of the M-Od, M-Ob-M and Si-Oa becomes more red-shifted when molybdenum is gradually substituted for the tungsten atom. In particular, the thermal decomposition of the heteropolyoxometalates was studied in nitrogen atmosphere. The TG-DTA curves show that their thermal behaviors not only contain the release of water molecule, DMF molecule, CTMA and its fragments but also contains simultaneous collapse of Keggin anion. Their end products of the thermal decomposition are the mixture of WO3, MoO3 and SiO2. And from the final decomposition temperature of view, it is found that the thermal stability of these compounds gradually is decreased when the number of molybdenum atoms is increased.     

Theoretical analysis of low-temperature hot source driven two-stage LiBr/H2O absorption refrigeration system

A detailed theoretical analysis is presented for a two-stage LiBr/H₂O absorption refrigeration system, which consists of an evaporator, a low-pressure absorber, a low-pressure generator, a high-pressure absorber, a high-pressure generator, a condenser, a low-pressure heat exchanger and a high-pressure heat exchanger, driven by a low-temperature hot source. A comparison of results from the theoretical analysis and preliminary experiment indicates that the theoretical analysis developed can represent a real system with a reasonable accuracy, and is useful for future development.     

四(二乙胺基)溴化鏻的合成及用于相转移催化Halex反应

四(二乙胺基)溴化鏻(TPB)是制备含氟芳香族化合物的一种新型相转移催化剂。以PCl3作原料经季鏻化、氨解、中和、烷基化4步反应合成了TPB,反应总收率41%,w(TPB)=90%。产物由31PNMR、1HNMR、MS进行了结构确证。并将该催化剂应用于Halex反应制备对氟硝基苯,初步考察了其催化效果,收率62%。     

用热管回收余热作热源的溴化锂冷热水机组

该文介绍了一种能回收利用工业废气制冷和制热的溴化锂冷热水机组；采用高效的“水-碳钢“热管换热器，传热效率高；分析了节能效果，论证了本机组有较好的节能效果。本机组可推广到很多具有废热可用的场合，具有很好的经济效益。     

北京某中心空调冷热源方案比较

本文对北京某中心空调系统设计进行了三种冷热源方案的比较：在整个采暖和空调季节进行初投资和运行费用的对比后，得出冰蓄冷加常规采暖系统具有较好的经济性。     

溴化锂吸收式制冷机冷剂水溢出故障分析及排除

叙述了溴化锂吸收式制冷机冷剂水溢出故障的分析及其排除方法。     

阳离子表面活性剂/醇/水三元体系液晶的研究

在25℃时绘制了阳离子表面活性剂3-辛烷氧基-2-羟丙基三甲基溴化铵(R8TAB)／正丁醇／水的三元体系的相图，在偏光显微镜下发现该体系中的某些区域呈现出彩色液晶。一些绚丽的彩色照片清楚地显示了不同的液晶纹理。用。HNMR和小角X衍射与纹理照片对照．确定了该体系的液晶结构类型，用差示扫描量热法证实了液晶结构的转化。研究分析了液晶层厚度、温度和时间对液晶颜色变化的影响，结果表明．液晶膜厚度是产生颜色的关键因素。     

The interfacial turbulence in falling film absorption: effects of additives

The results of vertical falling film experiments on the absorption of water vapor to aqueous lithium bromide solutions with an additive, 2-ethyl-1-hexanol, are reported. During the absorption, the film becomes highly turbulent. Consequently, the heat and mass transfer is significantly enhanced by turbulent mixing. In addition, the instability mechanisms are detailed. In the vicinity of water absorption, surface-tension gradients due to the lower LiBr concentration, the lower additive concentration, and the higher temperature at the interface, can favor instability of the falling film.