趋势分析法评价苯系物标准气体的时间稳定性

根据GB/T 15000.3—2008设计了苯系物标准气体的时间稳定性研究方案,制备了4瓶苯系物标准气体,随着时间的推移进行测定并将结果制图,结果显示量值随时间没有显著的变化趋势。以线性关系为模型,计算线性直线的斜率和斜率的标准偏差,用t检验判断斜率是否显著来评价标准气体的稳定性。计算结果显示,所有斜率均不显著,因此该研究制备的苯系物标准气体能够稳定保存22个月。根据时间稳定性数据计算由不稳定性引起的不确定度,并讨论了这种计算不稳定性引起不确定度的方法对结果有放大的可能性。     

Kinetic mechanism and effects of molecular structure on thermal hazards of azo compounds

In this paper, the kinetic mechanism of AIBN, AMBN, and ABVN was proposed, and the effect of molecular structure on their thermal hazards based on the kinetic mechanism was investigated. Calculated by non-isothermal DSC datum, the kinetic mechanism of AIBN, AMBN, and ABVN is revealed by the linear relationship between the integrated form of mechanical function and reaction time. The results indicate that the thermal decomposition process is controlled by the Johnson-Mehl-Avrami equation. Based on the determination of kinetic mechanism function, the reaction rate constants at various heating rates are directly calculated, and the intercept of the best fitting straight line of reaction rate constants with heating rate is approximately equal to the reaction rate constant under isothermal conditions. Besides, theoretical values obtained by multiplying kinetic mechanism function by reaction rate are well consistent with the experimental values, suggesting that the kinetic mechanism obtained is credible. Bond Dissociation Energies (BDE) calculated by quantum chemical equations are employed to evaluate the thermodynamics stability of AIBN, AMBN, and ABVN. Depending on similar molecular structures, the influence of differentiated group structure on the thermodynamic stability represented by BDE and heat release and the kinetic stability characterized by reaction rate constant were revealed. Finally, the results demonstrate that the thermal hazard increases as the volume of substituent group and molecular weight.     

Evaluation of thermal hazard characteristics of four low temperature reactive azo compounds under isothermal conditions

The polymerization reaction can lower the threshold of the required energy by the initiator to improve the efficiency of the overall process reaction. Emerging polymerization initiators are also a major focus of process improvement and technological progress. Azo compounds (azos), which used in dyeing applications, are subsequently used in polymerization reactions due to their highly exothermic reaction characteristics. Although higher heat release can promote polymerization and modify the product, heat generation may also cause process hazards.These thermal hazard parameters were studied by selecting dimethyl 2,2′-azobis(2,4-dimethylvaleronitrile) (ABVN), 2,2′-azobis(2-methyl propionate) (AIBME), 2,2′-azobis(2-methylpropionamide) dihydrochloride (AIBA), and 2,2′-azobis(isobutyronitrile) (AIBN), which are common azo initiators at present. Thermal hazards are closely related to the reaction kinetics of the substance itself. The form of the reaction, the apparent activation energy and the thermodynamic parameters of the exothermic mode were also obtained.Kinetic analysis of the actual process using the experimental data of the isothermal calorimetry model is rarely used in the evaluation of related thermal hazard characteristics. The simulation results revealed the kinetic azo models and were further applied to calculate the runaway situations of azo under specific boundary conditions.     

采用跟踪控温近似绝热系统测定火炸药热爆炸参数的探讨

本文针对以往在火炸药热爆炸参数测试过程中，因试样与加热介质之间的热交换所带来的较大测试误差，建立了跟踪控温下的近似绝热测试系统，研制了本测试系统的中枢仪器──四通道数显温度调节自动跟踪仪。通过本测试系统的建立，使得对热爆炸参数的测试更具有科学性和实用性。     

火电厂废水的净化与回收利用

针对火电厂废水悬浮物含量高、粒径小、难分离、废水量大的特点 ,采用高浊度废水净化技术 ,优化工艺流程 ,实现了火电厂所有废水的净化与回收利用 ,且经济效益显著。     

聚乙烯塑料类固体废弃物热裂化研究

在反应温度455-495℃,氢气压力0.1～4.0MPa和反应时间2～12h的范围内,就聚乙烯塑料类固体废弃物热裂化时温度、压力和反应时间的影响以及不同反应条件下产物的碳数分布、馏程变化进行了探讨,得出适合于生产柴油馏分的反应条件是温度475℃,常压或低压,反应时间4h等。     

废旧塑料的处理工艺

介绍了当前国内外几种处理和利用废旧塑料的方法，特别对废旧塑料掩埋、再生、回收焚烧、热裂解制造燃料油和化学品的技术和存在的问题作了重点探讨。     

空气中联苯——联苯醚的气相色谱法测定

以国产硅胶担体为固体吸附剂,采集空气中联苯-联苯醚。经热解吸、制冷、闪蒸后,用气相色谱法测定。实验结果,在常温下,国产硅胶对联苯-联苯醚的吸附率达100％;解吸回收率为97.5％:变异系数<5％;方法的检测限为0.4μg。     

废旧塑料热解催化及其产物分析

采用热解──催化法使废旧聚乙烯塑料裂解，并对裂解产物进行ＧＣ／ＭＳ分析．结果表明，废旧聚乙烯塑料的裂解产物主要由正构烷烃、烯烃及少量环烷烃组成．这些化合物均具有重要的回收利用价值．     

顺层边坡岩体结构稳定性分析

顺层边坡的失稳问题一直是工程地质学和岩石力学领域内极为瞩目和急待解决的问题之一。本文根据顺层边坡的地质背景及力学作用机制,抽象出了顺层边坡溃屈破坏的力学模型。利用板柱弹性稳定性理论,结合结构力学的知识,推导出了相应的计算公式。实例分析表明,利用文中的理论方法,并结合工程现场有效的量测手段,可方便、有效的判定顺层边坡的稳定性。