Conceptual design of a high-efficiency absorption cooling cycle

The search for high-efficiency, gas-fired cooling cycles has led to the development of dual-loop absorption machines with cooling coefficients of performance (COPs) in the 1.2 to 1.7 range. This increased performance may call for high generator temperatures, new working fluids or new materials of construction. In most cases, two different sets of working fluids are required. The conceptual design presented here is aimed at obtaining high efficiencies with relatively low temperatures, employing only one set of fluids. The concept consists of two loops coupled in a configuration aimed at minimizing the loss of thermodynamic availability incurred when transferring refrigerant between the loops. The working fluid pair is a solution of lithium bromide-water. The calculated COPs are of the order of 1.8. The cycle relies on an elaborate evaporator-absorber combination. The paper presents the conceptual design, the critical assumptions, and the performance calculations for the concept.     

Head-to-head polymers: 33. Bromination of cis-1,4-polybutadiene to head-to-head poly(vinyl bromide)

Cis-1,4-polybutadiene (PB) in a 0.5% solution of a solvent mixture of dichloromethane and 1,2-dibromoethane or tetrahydrofuran was quantitatively brominated with elemental bromine at 0°C under careful exclusion of oxygen to head-to-head poly(vinyl bromide). Partially brominated PB has a structure of random or block sequences of butadiene units in the polymer depending on the bromination solvent but shows no stereospecificity in the CHBrCHBr-dyads. Partially brominated PB with block structure showed a microphase-separated morphology over a wide range of composition. Microphase separation is less pronounced for the more random structure of butadiene units. I.r and ¹³C n.m.r. spectroscopy of the partially brominated PB was used to follow the progress of the bromination.     

The thermodynamic performance of a new solution cycle in double absorption heat transformer using water/lithium bromide as the working fluids

In this paper, a new solution cycle in the double absorption heat transformer is presented and the thermodynamic performance of this new cycle is simulated based on the thermodynamic properties of aqueous solution of lithium bromide. The results show that this new cycle is superior to the cycle being studied by some researchers. This new solution cycle has a wider range of operation in which the system maintains the high value of COP and has larger temperature lifts and operation stability. The relationship between the absorber and the absorbing evaporator is more independent and this makes the operation and control of the system more easier.     

聚甲基丙烯酰氧乙基二甲基丁烷基溴化铵共振光散射法测定核酸

通过光谱法研究聚甲基丙烯酰氧乙基二甲基丁烷基溴化铵(PMDB)和核酸的作用。结果表明通过共振光散射法用PMDB检测微量的DNA可靠、准确和简单。     

S-苄基-L-半胱氨酸的合成

由溴化苄和L-半胱氨酸直接合成S-苄基-L-半胱氨酸,通过正交试验及统计分析,检验了各影响因子的显著性,确定了最佳工艺条件为：反应时间2.5h,反应温度45℃,原料配比n（溴化苄）：n（L-半胱氨酸）=1：1.在此条件下反应,摩尔产率可达到95%.     

高分子和盐对3-十二烷氧基-2-羟丙基三甲基溴化铵泡沫性能的影响

测定了3-十二烷氧基-2-羟丙基三甲基溴化铵(C12TAB)在PVP、PEG和溴化钠存在下的泡沫性能。结果表明：含量相同时，C12TAB／NaBr混合体系的起泡性能高于C12TAB／高分子体系，而稳泡性能低于后者。含量相同的C12TAB／高分子体系，PVP对C12TAB的影响好于PEG。     

Ionic liquid as reaction medium for the synthesis and crystallization of a metal-organic framework: (BMIM)2[Cd3(BDC)3Br2] (BMIM = 1-butyl-3-methylimidazolium, BDC = 1,4-benzenedicarboxylate)

An ionic liquid, 1-butyl-3-methylimidazolium bromide, is used as reaction medium for the synthesis and crystallization of a coordination polymer, (BMIM)₂[Cd₃(BDC)₃Br ₂] (1) (BMIM = 1-butyl-3-methylimidazolium, BDC =  1,4-benzenedicarboxylate), which forms an anionic two-dimensional framework with the imidazolium cations located between the layers. This compound is thermally stable up to ca. 340 °C and exhibits blue emission in solid state at room temperature. Other characterizations by IR and UV–visible spectra are also described.     

Study on the polymerization of ϵ‐caprolactam in the interlamellar spaces of [TEACOOH]–montmorillonite intercalations complex and its characterization

The polymerization of ?‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ?‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003     

十六烷基三甲基溴化铵活化催化合成香豆素

以无水碳酸钾为催化剂、十六烷基三甲基溴化铵(HTMAB)为活化剂，用水杨醛和醋酸酐为原料通过Perkin反应合成香豆素，研究了物料比、催化剂用量和HTMAB用量和反应近结束时保温时间对产率的影响。结果表明：用HTMAB为活化剂，可有效活化碱催化剂无水碳酸钾，提高了其碱性，与无HTMAB时相比，香豆素产率有较大提高，其最佳反应条件是n(水杨醛)：n(乙酸酐)：n(碳酸钾)：n（HTMAB)为1．00：3．00：0．25：0．03，反应温度185℃，反应近结束时保温3h，香豆素产率可达85．3％。     

浅析氯化氢合成余热利用

介绍了采用热水型溴化锂机组对氯化氢合成中产生的余热的利用,通过计算,对比分析了节能效果。