剩余函数法预测纯物质汽化热

在纯物质常沸点汽化热的剩余函数预测法基础上,结合Watson方程,推导出预测纯物质任一温度下汽化热的新方程,由最基本物性数据T_b、T_c和P_(?),预测350种各类物质13117个温度点的汽化热,与文献常用值相比较的总绝对平均误差为2.8％。     

量热法研究缓蚀作用

<正> 前言研究金属在酸中的腐蚀及缓蚀作用多采用失重法,量气法,电化学法,比色分析法等,失重法为经典方法,但操作较繁。其它方法虽各有一些优点,但均费时,仪器要求也较高。近年来,国外采用Mylius的量热法研究缓蚀剂的缓蚀作用,此法所用仪器简     

绝热量热法测量高分子凝聚液比热容

利用精密自动绝热比热容实验装置，测量了丁苯橡胶合成过程中高分子凝聚液的比热容数据，为大型丁苯橡胶合成装置建造提供了基础物性数据。     

图论法预测纯物质常沸点汽化热：饱和烷烃和链烯烃汽化热的预测

本文以图论法为基础,提出了一个预测异构烷烃和链烯烃常沸点汽化热的计算方程式:应用该式对50种饱和烷烃和25种链烯烃的汽化热分别进行了预测。结果表明,预测的精确度和简便性都是令人满意的。     

纯物质汽化热的预测

在纯物质常沸点汽化热的剩余函数预测法的基础上,结合并改进W-S方程,推导出预测纯物质在任一温度下的汽化热的新方程。由最基本的物性数据T_b,T_c,P_c,预测245种各类物质7574个温度点的汽化热,与实验值相比较的总绝对平均误差为1.77％,优于原剩余函数法。     

剩余函数法预测纯物质的常沸点汽化热

本文根据化工热力学原理把剩余函数概念扩展到用于纯物质的汽化热,引入Clapeyron方程式和Pitzer三参数对比状态普遍化关系式,再代入Edmister方程式,推导出纯物质常沸点汽化热的新计算方程式.应用该方程式,由最基本的物性数据T_b、T_c和P_c,预测了390种各类物质的常沸点汽化热,与文献实验值相比较,总的绝对平均误差为2.0%.     

鹿耳促菌作用的量热法研究

用热活性检测仪测定了茸对大肠杆菌,金黄色葡萄球菌起促进代谢作用的热功率－时间曲线,并根据曲线建立了细菌促进生长的实验模型,计算了生长速率常数和最佳促菌浓度。     

应用分子聚集理论改进剩余函数法预测纯物质常沸点汽化热

在剩余函数法预测纯物质常沸点汽化热的基础上,应用分子聚集理论导出的维里方程,推导出预测纯物质常沸点汽化热的新方程。通过390种各类物质检验,表明新方程优于原剩余函数法的预测结果。     

聚酯的差示扫描量热法热性能分析

使用DSC差示扫描量热仪分析了三种聚酯产品的热性能。同等试样量时,从测得试样的熔点、结晶度及曲线图形可以分析判断出,PET-2聚酯样品产品质量最好。     

GENERALIZED METHOD FOR CALCULATING LATENT HEAT OF VAPORIZATION

The latent heat of vaporization of a pure substance is often required in many engineering design/process calculations. Knowledge of the latent heat of vaporization can be of particular value when dealing with a material for which complete enthalpy data are not available. A method has been developed for making accurate reliable estimates of the latent heat of vaporization when only the vapor pressure and the critical constants of the material are known.     

Thermogravimetric determination of the heat of vaporization of some highly polar solvents

Thermogravimetry was employed successfully in determining the enthalpies of vaporization of some industrially important solvents. The data obtained from the thermograms pertaining to weight loss were used for evaluating the rate of evaporation of the samples and were substituted in a form of the Clausius—Clapeyron equation for such determinations. Values of the enthalpies reported, using the thermogravimetric technique, were repeatable to within 1% and with an accuracy better than ±5% of the true values at the temperatures reported. Comparison with data obtained from other sources appears to be quite satisfactory.     

预测不同温度下有机纯质汽化热的新方程

阐明Watson公式的不足和缺陷,应用分子热力学理论揭示出液体的汽化热取决于液体的分子间相互作用力,导出预测不同温度下有机纯质汽化热的新方程,其物理意义明确.经用39种结构类型的310个实验值检验,平均误差0.69%.Watson式为3.06%,本法的精度比Watson式高4.4倍以上.     

Vacuum Drying of Porous Solids under Supercooling

Vacuum drying of sintered glass beads, cemented glass balloons, and baked clay was investigated under supercooling. Glass beads and glass balloons, which were made of a common glass material, were used for comparison. Concerning sintered glass beads, there was no effect of supercooling on drying rates at a pressure of 0.93 kPa. In cemented glass balloons as well as in baked clay, however, a prominent peak of drying rates emerged in drying rate curves and at the same time, a stepwise increase in the surface temperature appeared under supercooling at a pressure of 1.19 kPa; no peak of drying rates emerged in drying rate curves of sintered glass beads. The total amount of latent heat of vaporization and sensible heat generated at the peak of drying rates was 39-59% of the latent heat of solidification. A part of the latent heat of solidification evaporated the water in the sample, producing a peak of drying rates as well as a stepwise increase in the surface temperature of the sample.     

立方型状态方程用于蒸发热的计算

推导出立方型状态方程计算纯流体蒸发热的新公式,该计算式的特点是式中含有能量参数对温度的导数 da/dT,而与 a(T)无关。根据这一公式对立方型状态方程推算蒸发热进行了比较分析,提出a(T)与 da/dT 相互独立的计算方法,并用 Peng-Robinson 方程对70多种物质(包括烃、醇、卤代烃、酮、无机气体等)进行了关联计算,蒸汽压和蒸发热的平均相对误差分别为0.70%和1.33%。     

用相对分子质量描述同系物的蒸发热

本文用Y=A·1M+B·1M/(C1+M)作为经验规则,对正烷烃等23类同系物的蒸发热与其相对分子质量作了关联,并与另一经验规则Y=A·M+B·M/(C+tb)作了比较。     

Determination of environmentally relevant physical-chemical properties of some fatty acid esters

Fat models frequently use input parameters that are defined at environmental conditions. In a recently developed gas-liquid chromatography method (GC-VAP), vapor pressures, heats of vaporization, and heat capacity differences (gas-liquid) of fatty acid esters are determined over a large temperature range that includes environmental temperatures. This method also allows an accurate determination of the normal boiling point temperature of a substance. Literature values of vapor pressure, boiling point temperature, and heat of vaporization at 298.15 K for the chosen esters are all in excellent agreement with those determined with the developed method. Correlations between carbon number and heat of vaporization are high.     

非极性有机物蒸发热与正常沸点的关联

通过对正烷烃蒸发热、正常沸点与碳数关系的研究,理论推导出蒸发热与正常沸点之间的关系,并拟合得一简单适用的公式:Hυ=23.234×BP1.21256+1502.13。应用于上百种常见非极性有机物,误差较小。     

氯化石蜡-52生产中余热的利用

根据氯化石蜡的生产特点,提出了合理利用生产中反应余热的思路,并简要介绍了该项技术改造方案及其经济效益。