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反应焓变的测定是普通化学、无机化学教学的常规实验。实验用量热计大致可分为两种类型:即保温杯型[2~5]和烧杯夹泡沫塑料绝热型[5~7];采用的搅拌方法则有手握量热计摇动搅拌[1]、手握玻璃棒(或下端加环)上下移动或转动搅拌[2,3]、电动搅拌机搅拌或电磁搅拌器搅拌[5]。经过长期实践,已发现现有各种简易量热计存在如下问题:(1)搅拌过程中容易碰破量热计内壁或温度计;(2)手动搅拌不充分、不均匀,反应时间长,由此带来实验误差大;(3)烧杯夹泡沫塑料型量热计,在清洗过程中夹层容易进水,热容变化进而导… 相似文献
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用溶解量热法,以KIO_4和KOH组成的弱碱性溶液为量热溶剂,设计3个不同的热化学循环,用RD-1型热导式自动量热计测定了MoO_3的标准生成焓,并推荐其值为ΔH_(t(moO_3))~0(298.15K)=-765.0±6.8kJ·mol~(-1)。 相似文献
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量热法测定氯化钐与甘氨酸配合物的标准生成焓 总被引:2,自引:0,他引:2
稀土在生命科学领域的研究日益受到人们关注,稀土化合物所具有的抑菌、抑癌、消炎等作用及其作用机理的探讨已有报道[1~3]。最近几年稀土在生物领域中的研究又有了新的突破和进展,从稀土与氨基酸、蛋白质、膜脂及膜蛋白的作用到其对DNA。RNA的影响[1,4],从稀土的分子水平、细胞及亚细胞水平到动物整体实验的系统研究[5,6]等,分别从不同的层次、不同的水平研究了稀土的生物效应。但至目前为止,稀土的生物效应机理及其对人体的影响尚未得到令人满意的解释。由于氨基酸是构成人体蛋白质的基本单位,故研究稀土与氨基… 相似文献
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石油馏分恒压比热容与焓的研究 总被引:2,自引:0,他引:2
用差示扫描量热计(DSC)测定5个国产原油馏分在系列温度下的恒压比热容,给出比热容与温度的关联式。经标准物质α-Al2O3和正庚烷的恒压比热容测定表明,与文献数据的平均偏差在±2%以内。由恒压比热容计算馏分相应温度下的焓,与落入式铜量热计直接量热所得的结果比较,符合良好。还考察8个恒压比热容计算方法的这些馏分的适用性。 相似文献
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由于锂离子电池安全问题的严重性,它的热性质一直受到很大重视。对电池的热性质表征,传统方法主要包括单组分的热重(TG)、示差扫描(DSC)、加速量热法(ARC)等测量。由于体积较大,对于整池的热物性研究主要依赖于加速量热仪或充电/放电过程的温度检测。整池充放电过程的热耗散/吸收过程只能利用热导式量热计进行,如我们曾利用Calvet量热计对AA型Ni-MH电池在充放电过程中的热耗散进行过研究。 相似文献
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由于锂离子电池安全问题的严重性,它的热性质一直受到很大重视.对电池的热性质表征,传统方法主要包括单组分的热重(TG)、示差扫描(DSC)、加速量热法(ARC)等测量.由于体积较大,对于整池的热物性研究主要依赖于加速量热仪或充电/放电过程的温度检测. 相似文献
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It has been found that an ordinary reaction calorimeter can be used for the determination of small heat effects (10^-^3 to 10^-^4 C temperature change) by correctly evaluating the Newton's cooling constant K through a reference temperature technique. This technique was applied to the determination of the integral enthalpies of solution of L(+)-aspartic acid and L(+)-glutamic acid in water in the concentration range of 10^-^3 to 10^-^4 mol/kg which were found equal to 25.8+/-0.6 and 25.7+/-0.4kJ/mol respectively (twice standard deviation). No CH2 increment effect has been revealed in the solution enthalpies of these two amino-acids. 相似文献
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本文提出, 以不同的电热功率, 对稀释后的系统分别进行升温的方法, 求出K值, 进而计算出热容C. 相似文献
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In this paper, it is made a study of the accuracy of an isothermal titration calorimeter in the operating mode of ‘continuous
injection’. The experimental equipment has been a TAM2277-201/2250 by Thermometric AB and the liquid mixtures used in the
calibration have been the mixture cyclohexane+benzene and the mixture water+ethanol. The calibration contemplates different
effects that affect the uncertainty in the determination of the sensitivity, the effect of the liquid injection, the treatment
of the calorimetric signal, the variation of the experimental baseline and the different noises included in the calorimetric
signal. 相似文献
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By using electrical calibrations and with the injection
of liquids with very different heating capacities (water and cyclohexane),
it is made a thorough evaluation of the ‘injection effect’ in
terms of the parameter ρc
p
f (ρc
p
– volumetric heat capacity, f –
injection flow) in an isothermal titration calorimeter. This effect can be
evaluated accurately in the case of non-volatile liquids, however, when dealing
with volatile liquids, the uncertainty in their determination increases because
of the vaporization heat. 相似文献
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The suitability of the SETARAM high temperature calorimeter for the determination of mixing enthalpies of liquid metallic alloy systems has been investigated. Several methods of calibration were investigated as well as the dependence of the calibration factor on total mass in the crucible and volume of the crucible occupied. The results indicate that calibration with an inert substance, such as tungsten or molybdenum, during the course of the mixing experiments is the optimal procedure. Heats of mixing for liquid AuSn and CuSn alloys were determined at 1380 K and 1440 K, respectively, and compared with literature values. The agreement of the values obtained here and those in the literature is satisfactory. 相似文献