转动弹精密量热计的研制

该仪器采用潜水式,结构设计合理,精密度高。按环境等温和绝热跟踪两种方式工作,温度测量采用石英频率温度计,实现了高精密度下的自动化和打印,温度控制的波动范围在±0.001K以内。     

转动弹燃烧量热计与噻蒽燃烧热的测定

本文叙述了转动弹量热计的建立。用本实验室自制高纯苯甲酸标定了量热计的能当量,其精密度为0.02％,利用本仪器测定噻蒽的燃烧热值 -△E~_c~0=1730.26±0.52千卡/克分子。     

汽化热量热计的建立及物质汽化潜热的测定

在J.H.Mathews仪器的基础上进行适当改进,本文建立了一种等温绝热型汽化热量热计,经对甲醇、乙醇、苯、甲苯和水等物质的测定,精度可达0.1-0.2%,与文献值对比,准确度在0.3%以内,在纯物质测定的基础上,对水+乙醇、苯+甲醇两个二元物系进行了等压积分汽化潜热的测定,文中对采用“差分-积分图”方法反映汽化过程中体系的焓变作了一些探讨,另外,本文还就我国石油轻馏分汽化热的测定进行了初步的探索和研究。     

精密转动弹量热计和有机氯化物的热化学研究

本文叙述了精密绝热、恒温两用转动弹量热计的建立,并用本实验室自制的高纯度苯甲酸标定了量热计的能当量,其精密度在绝热和恒温条件下分别为0.02%和0.007%,利用此仪器测得对氯苯甲酸、鲨烷和全氯间苯二腈的燃烧热值⊿E_c⁰,分别为-3062.06±0.42,-19,765.64±1.86-3,4s6.72±2.21kJmol^-1,利用上述数据和CO₂(g),H₂O(1)和[HCl·600H₂O](1)的标准生成热,导出此三种化合物的生成热⊿H_i⁰分別为-420.71±1.16,-861.97±5.89和189.57±4.59kJmol^-1.     

等温稀释型量热计的建立和过量焓的测定

本文建立了一套等温稀释型量热计, 该量热计可用于吸热型体系过量焓的测定,量热计灵敏度为2μV.J^-^1, 恒温精度为±8*10^-^3K。经环己烷-苯体系和环己烷-正己烷体系在298.15K时标定, 精确度在15%以内, 测定了缔合体系在乙醇 -苯体系303.15K时溶液的过量焓。     

敏感1000倍的量热计

敏感１０００倍的量热计ＩＢＭ的科学家们开发了一种新的量热计。这种量热计比原有的量热计对温度要敏感１０００倍，其检测温度变化的范围可达１０－５Ｋ，且价格相对低廉。这种量热计的基点在于一个镀有铝层的微型机械硅杠杆。由于硅和铝的热膨胀系数不同（双金属效应）...     

对氨基苯甲酸热力学性质的量热和热分析研究

在80～400 K温区,用高精度全自动绝热量热仪测定了对氨基苯甲酸摩尔热容,得到摩尔热容随温度的变化的关系式为：     

聚四氟乙烯等温稀释型量热计

过量焓是溶液的基本热力学性质,近廾年来不少学者对它进行了大量的研究,取得了引人注目的成绩。目前应用较多的为等温稀释型及流动型量热计。尽管后者具有速度快、试剂用量省等优点,但前者结构简单、操作方便和实验精度高,因此得到广泛的应用。传统的等温稀释型量热计的本体为玻璃杜瓦瓶,当活塞上下移动时常常引起破裂,另一方面由于使用汞封,使实验物料受到很大限制。为了克服这些缺点,我们用聚四氟乙烯作为量热计本体,取得满意的效     

感温电阻式热导量热计的研制

目前国内外生产和应用的热导量热计其感温系统多为热电堆。这种类型的量热计由于涉及几十对甚至几百对热电偶的焊接和安装,难于做到处于孪生体系的两个量热单元完全对称,热电偶金属的长短、焊点的大小和形状、绝缘层的厚薄和安装松紧等都是造成不对称的根源。这就容易使量热计的稳定性受到影响。     

一种新型的量热计研制成功

对量热方法的研究是量热学的一个重要课题。目前,我国通用的量热计有恒温外套式和绝热式两种,但由于一般尚未实现自动化,其量热操作十分繁琐,而且灵敏度也不够高,有些重要过程的微小热量还不能测定.近代,国外发展了一种新型的热导式自动量热计,具有很高的灵敏度,能够自动测量和记录各种非常微小的热效应,用途十分广泛。六十年代以后,我国向国     

Method for Measuring the Combustion Heat of Natural Gas with Isothermal Calorimeter

Factors that are to be taken into account in developing a calorimetric technique are considered. The possible deviations of temperatures at the inlet and outlet of gases in the calorimeter from the nominal values are evaluated and an example of such estimate is given for the case of methane burning in batch and continuous operation modes. The necessity for taking into account the humidity of gases fed into the calorimeter burner is demonstrated. The proposed method was used to perform absolute measurements of the combustion heat of methane.     

Design and Study of Gas Calorimeter for Absolute Measurements of the Combustion Heat of Natural Gas

A novel burning calorimeter design based on a heat pipe is presented. A circuit for automated control over operation of the proposed device is considered. The stability of the results is assessed. Several accessory parameters affecting the reproducibility of measurement results are evaluated. One of recent designs of the KTT-7 calorimeter, based on a thermosiphon, is analyzed. The uncertainty in heat power measurements on KTT-7 is evaluated.     

精密溶解量热装置的建立与标定

本文报道了自行建立的用热敏电阻作为测温元件的精密溶解量热装置,并用量热标准物质光谱纯氯化钾和美国国家标准局提供的三羟甲基氨基甲烷(TRIS)对仪器进行了标定,在25℃所得实验结果:KCI溶解焓为17518±15 J·mol~(-1);TRIS与0.1 mol/L HCI的反应焓为-29729±31J·mol~(-1),与文献值吻合,检验了该装置的可靠性.     

粗略测量乙醇燃烧热的实验探究与反思

基于"粗略测定乙醇燃烧热"实验及其改进为案例, 针对实验结果和实验过程进行了探究分析;引导学生在简陋粗糙的实验条件下理解原理, 体验过程, 感悟控制实验条件对实验结论的重要性;从激发学生的学习效能感、"过程学习"的评价方式等角度对教学活动提出了建议。     

氧弹式量热法测燃烧热实验的改进

本文讨论了氧弹式量热计的改进方法 ,并对仪器装置和实验原理进行了分析 ,最后给出了仪器改进前后部分实验结果的比较 ,从中可以看出 ,实验准确度有较大的提高。     

一套恒温环境连续式滴定量热装置的建立及其热谱图分析方法的改进

根据滴定量热原理,结合国内实际建立了一套恒温环境连续式滴定量热计。经各种物理性能测试表明,仪器运行稳定可靠,灵敏度为9.91×10^-5kmm^-1,经化学标定(HClO₄+NaOH)测得△H_N⁰=-13.341±0.0181kcalmol^-1。用本仪器测定银(Ⅰ)-吡啶两级配合物的稳定常数和生成焓,结果与文献值吻合。     

Determination of Crystallization and Melting Behaviour of Poly-lactic Acid and Polypropyleneblends as a Food Packaging Materials by Differential Scanning Calorimeter

The food packaging materials commonly used is made from polymers synthetic base on petroleum derivatives. However, the use of synthetic polymers has negative impacts on the environment, because it is difficult to degrade naturally either by biotic or abiotic process. This is a problem for the environment and therefore it needs to do the assessment of the technology to reduce the degree of difficulty on its degradation or to find a new material that can be degradable naturally. One of the most important properties of food packaging materials is the polymer crystallinity. This refers to the overall level of crystalline component in relationship to its amorphous component. It is directly related to many of key properties exhibited by a semi-crystalline polymer including brittleness, toughness, stiffness or modulus, optical clarity, creep or cold flow, barrier resistance and long-term stability. Thus, in this study, PP blends with the PLA and meltsat 250^oCfor 4 hours, and investigates their crystallization and melting behavior using DSC at cooling rate of 10 and 40^oC/min. The results show that base on their thermograms, with increasing the cooling rate will decreasing the crystallinity or increasing amorphous area underthe peaks.     

Construction of an Isoperibol Calorimeter to Measure the Specific Heat Capacity of Foods Between 20 and 90°C

A simple isoperibol calorimeter, using the modified method of mixtures, was developed to measure the average specific heat capacity of different dough types between 20 and 90°C. The method consisted of encapsulating the sample in a copper cylinder and immersing the capsule in water at a different temperature. The procedure was tested for reliability with distilled water and whole fat milk before applying it to five dough types of varying moisture and fat contents. Mean values of 4.176±0.008 kJ kg^-1 K^-1 and 3.942±0.034 kJ kg^-1 K^-1 were obtained for distilled water and milk respectively, which agree within 0.23 and 0.34% from reported values. The specific heat values for the five dough types were found to range between 2.15–2.68 kJ kg^-1 K^-1 between 2.35–3.10 kJ kg^-1 K^-1 and between 2.40–3.19 kJ kg^-1 K^-1 at the three temperature levels studied. The specific heat capacity was found to depend not only on the moisture level but also on the fat content, especially for dough types with a high percent of fat. Regression analysis was then used to correlate these values and develop a set of empirical equations. The results were used to assist in energy balance calculations in backing oven for industrial purposes. This revised version was published online in July 2006 with corrections to the Cover Date.     

二甲氧基嘧啶胺与金属配合物的恒容燃烧热测定

在无水乙醇中，使钴、铜、锌、锰的盐与二甲氧基嘧啶胺(AMP)反应，回流数 小时后，浓缩、冷却，抽滤，制得了6种二甲氧基嘧啶胺与钴、铜、锌、锰的固态 配合物．用化学分析和元素分析确定了它们的组成，分别为Co(AMP)_2Cl_2(1)， Cu(AMP)_2Cl_2(2)，Cu(AMP)_2(NO_3)_2(3)，Zn(AMP)_2Cl_2(4)，Mn(AMP) _2Cl_2(5)和zn(AMP)s04(6)；用IR，～1H NMR研究了他们的成键情况；用精密转动 弹热量计测定了配体及配合物的恒容燃烧热△_cU，计算了它们的标准摩尔燃烧焓 △_cH_m～θ和标准摩尔生成焓△fH_m～θ．