硬脂酰氧基乙酸锌作为PVC热稳定剂的研究

以硬脂酸锌和氯乙酸为原料，制备了硬脂酰氧基乙酸锌．以硬脂酸锌作为对照物。通过热老化箱实验法、刚果红试纸法等多种方法对硬脂酰氧基乙酸锌及硬脂酰氧基乙酸锌／硬脂酸钙进行了热稳定性的研究．结果表明，硬脂酰氧基乙酸锌对PVC具有一定的热稳定性能，与硬脂酸钙具有较好的协同作用。     

硬脂酰氧基乙酸锌作为PVC热稳定剂的研究

以硬脂酸锌和氯乙酸为原料,制备了硬脂酰氧基乙酸锌.以硬脂酸锌作为对照物,通过热老化箱实验法、刚果红试纸法等多种方法对硬脂酰氧基乙酸锌及硬脂酰氧基乙酸锌/硬脂酸钙进行了热稳定性的研究.结果表明,硬脂酰氧基乙酸锌对PVC具有一定的热稳定性能,与硬脂酸钙具有较好的协同作用.     

PVC热稳定剂五（巯基乙酸异辛酯）锑的合成及其性质

以焦锑酸钠与巯基乙酸异辛酯为原料，用一步法合成了五（巯基乙酸异辛酯）锑，并用红外光谱对产品进行了分析，实验结果表明，当焦锑酸钠与巯基乙酸异辛酯的量比为1．2：1．0时，以甲苯为溶剂，加热回流3．5h，即可得到目标产物五（巯基乙酸异辛酯）锑，其收率为92．8％；当五（巯基乙酸异辛酯）锑在PVC中加添加量为2．5％时，PVC的热稳定时间为40min(20℃时）；当其与硬脂酸钡复配时，表现出协同作用。     

氯化聚氯乙烯的热稳定性配方研究

利用刚果红法研究热稳定剂三盐、两盐、钙锌复合稳定剂、有机锡、硬脂酸钙对氯化聚氯乙烯(CPVC)的稳定作用, 研究结果表明:铅盐类稳定剂稳定效果较好,各种稳定剂之间具有协同效应。在考虑环保要求的基础上确定较佳的CPVC配 方。     

氯化聚氯乙烯的热稳定性配方研究

利用刚果红法研究热稳定剂三盐、两盐、钙锌复合稳定剂、有机锡、硬脂酸钙对氯化聚氯乙烯（CPVC）的稳定作用，研究结果表明：铅盐类稳定剂稳定效果较好，各种稳定剂之间具有协同效应。在考虑环保要求的基础上确定较佳的CPVC配方。     

红外光对魔芋葡甘聚糖影响研究及优化

以纯化魔芋葡甘聚糖（KGM）为研究对象,探讨了红外光照射时间及温度与KGM粘度的相关性,经单因素和响应面试验研究表明,红外光对KGM的影响主要源于红外光产生的辐照热,与KGM含水量有一定关系,而与光的强弱没有明显相关性.响应面优化实验结果显示,在56.50℃红外光持续照射40.30h对KGM有很好的干燥效果,且不会破坏KGM分子结构.     

土壤源热泵热响应测试研究进展及分析

对土壤源热泵热响应实验的发展进行了综述和分析.回顾国内外热响应实验的发展,简述热响应的概念和相关理论,论述国内外研究现状及发展动态,分析热响应测试结果的影响因素,如采用闭环控制克服电网波动、稳定功率和流量,并给出相应措施.最后给出目前存在的问题及发展方向.     

硬脂酸锌催化非光气合成甲苯二氨基甲酸甲酯的研究

考察了多种Ｌｅｗｉｓ酸催化剂在用碳酸二甲酯代替光气与２,４－二氨基甲苯反应合成２,４－甲苯二氨基甲酸甲酯（ＴＤＣ）过程中的催化活性．在研究条件下,催化活性排序为：硬脂酸锌＞醋酸铀酰锌＞醋酸钴＞钛酸四丁酯＞氯化亚锡．用Ｌ９（３４）正交表设计安排了实验,优化了以硬脂酸锌为催化剂的反应条件．在最优反应条件下,ＴＤＣ收率为９５．５％．利用ＸＲＤ、ＩＲ,研究了催化剂在反应前后的变化,确定了其失活的主要原因．     

化学共沉淀法制备M型钡铁氧体研究

将均匀设计方法应用于化学共沉淀法制备M型钡铁氧体．经XRD、SEM等技术并结合均匀实验结果,研究合成因素Fe／Ba摩尔比、滴定时间、滴定温度、溶液pH值、晶化时间、晶化温度、预烧温度、预烧时间、煅烧温度、煅烧时间对所合成的M型钡铁氧体的影响．利用多元线性回归分析对均匀实验数据进行处理,分别得到了各影响因素与合成物相对结晶度、杂质相含量及颗粒径厚比间的函数关系,由此揭示了对各实验指标产生影响的因素及其影响主次顺序,确定了各实验指标的因素最优水平取值,为制备优良性能BaFe．2019提供了基础．     

响应面法优化硬脂酸淀粉酯合成的研究

以小麦淀粉为原料,硬脂酸为酯化剂,盐酸为催化剂,在干法条件下合成硬脂酸淀粉酯.通过单因素实验研究了各因素对产品取代度(DS)和反应速率(RE)的影响,确定了合成硬脂酸淀粉酯的适宜工艺条件:盐酸用量(淀粉干基)0.05%、体系含水量20%、硬脂酸添加量(淀粉干基)3%、反应时间180 min、反应温度150℃,得到取代度为0.013 8的产品.在单因素实验的基础上,通过响应面实验得到最优工艺条件,获得取代度为0.014 2的产品.     

Thermal Wave Effect and Sintering Activation Energy at the Initial Stage of Field Assisted Sintering Process for Non-conductive Al_2O_3 Powders

The effect of thermal wave at the initial stage for non-conductive Al_2 O_3 powders compact in field assisted sintering technique(FAST) was investigated. The Lord and Shulman type generalized thermoselastic theory was introduced to describe the influence of thermal-mechanical interaction, as well as the heat transport and thermal focusing caused by thermal wave propagation. The expression of vacancy concentration difference of the particles was deduced by considering transient thermal stress. Subsequently, the relationship between activation energy and vacancy concentration difference was obtained. The mechanism of surface diffusion, volume diffusion, simultaneous surface and volume diffusion was analyzed. The numerical simulations indicate that low sintering temperature can obtain high local temperature by the superposition effect of thermal wave. Vacancy concentration differences were improved during FAST compared with hot-pressure and pressureless sintering, thereby decreasing the sintering time. By contrast, the activation energy declined with the decrease of vacancy concentration difference in the neck growth process.     

Thermal Wave Effect and Sintering Activation Energy at the Initial Stage of Field Assisted Sintering Process for Non-conductive Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Powders

The effect of thermal wave at the initial stage for non-conductive Al₂O₃ powders compact in field assisted sintering technique (FAST) was investigated. The Lord and Shulman type generalized thermoselastic theory was introduced to describe the influence of thermal-mechanical interaction, as well as the heat transport and thermal focusing caused by thermal wave propagation. The expression of vacancy concentration difference of the particles was deduced by considering transient thermal stress. Subsequently, the relationship between activation energy and vacancy concentration difference was obtained. The mechanism of surface diffusion, volume diffusion, simultaneous surface and volume diffusion was analyzed. The numerical simulations indicate that low sintering temperature can obtain high local temperature by the superposition effect of thermal wave. Vacancy concentration differences were improved during FAST compared with hot-pressure and pressureless sintering, thereby decreasing the sintering time. By contrast, the activation energy declined with the decrease of vacancy concentration difference in the neck growth process.     

Thermal insulation and cooling properties of thermal barrier coatings of flame baffles

In order to study the thermal insulation and cooling properties of thermal barrier coatings of a flame baffle,several ZrO2 thermal barrier coatings with different thicknesses were prepared on the surfa...     

时效和热循环对CnZnAl系合金记忆性能的影响

本文研究了CuZnAl系合金去稳定化处理后,经马氏体状态长时间时效以及多次热循环时记忆特性的稳定性。结果表明,马氏体稳定化去除彻底的材料,在马氏体时效及热循环过程中记忆特性将基本保持不变,而去稳定化不彻底的材料,在马氏体时效过程中尚有再稳定化现象;在多次热循环过程中仅使A_s有所下降,而恢复率仍保持低值。     

响应面优化光催化降解低浓度富马酸废水

采用TiO2光催化氧化处理低浓度富马酸废水。在单因素实验基础上,通过响应面分析法中Box-Behnken进行实验设计,以废水初始浓度、pH值、催化剂投入量及光照时间作为变量,以废水的降解率作为响应量,研究不同变量对富马酸废水降解效率的影响及其交互作用。实验结果表明,该处理方法对富马酸废水具有很好的降解效率,光催化降解富马酸过程符合一级降解动力学过程;二次多项式的拟合优化结果表明,光照时间和废水pH值的交互作用显著。优化出的降解低浓度富马酸的最佳工艺条件是:废水初始浓度为68.76 mg/L时,催化剂投加量为0.06 g,pH值为5.01,反应时间为48.67 min,在该操作条件下降解效率可以达到97.41%。     

Numerical and experimental evaluation on methods for parameter identification of thermal response tests

Several parameter identification methods of thermal response test were evaluated through numerical and experimental study. A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal conductivity had been known in the simulation of thermal response test. The thermal response curve was firstly obtained through numerical calculation. Then, the accuracy of the numerical model was verified with measured data obtained through a thermal response test. Based on the numerical and experimental thermal response curves, the thermal conductivity of the soil was calculated by different parameter identification methods. The calculated results were compared with the assumed value and then the accuracy of these methods was evaluated. Furthermore, the effects of test time, variable data quality, borehole radius, initial ground temperature, and heat injection rate were analyzed. The results show that the method based on cylinder-source model has a low precision and the identified thermal conductivity decreases with an increase in borehole radius. For parameter estimation, the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal conductivity.     

响应面法优化家蝇幼虫中抗氧化成分的提取工艺

以家蝇幼虫为原料,以1,1-二苯基苦基苯肼（DPPH）自由基清除率为指标,采用响应面法对其抗氧化成分的提取工艺进行优化．在单因素试验的基础上,采用全因子试验的方法,分别对提取条件中的甲醇体积分数、温度、时间三因素进行研究;通过二次回归方程解得出最佳配比为甲醇体积分数为36％,提取时间为4．8h,提取温度为18℃。经试验表明,在此条件下提取液对1,1-二苯基苦基苯肼（DPPH）自由基清除率为81．9％,与理论值接近．     

仿生形态表面气固冲蚀磨损性能

根据试验优化设计理论,利用L27(313)三水平正交表设计试验,对具有凹坑形、凹槽形、圆环形仿生形态表面的试件进行冲蚀磨损试验研究,运用极差分析处理试验数据,得到三种表面形态试件的冲蚀率与各试验因素之间的关系。结果表明:试验因素对冲蚀率的影响程度由大到小依次为砂子目数、转速、喷砂量、形态;冲蚀率随着目数、转速的增大而增大;所有一级交互作用中,形态和喷砂量之间的交互作用对冲蚀率的影响最大,目数和转速之间的交互作用对冲蚀率的影响最小。     

液化场地桩基加速度反应试验与数值模拟

为研究液化场地桥梁桩基加速度反应特性,采用自编的土-结地震相互作用有限元分析程序,输入三种试验记录工况,进行可液化场地桥梁桩基地震反应振动台试验与数值模拟.结果表明:三种地震输入下,自下而上沿桩-柱墩长度方向,加速度峰值放大系数变化基本一致且均出现在10～20s时段内,加速度时程曲线的形状也极其相似;压缩0.15g El Centro波输入下加速度反应在砂土层与黏土层过渡带有增大趋势、在地表则有一定程度减小,且压缩0.15g El Centro波较0.15g El Centro波输入下均偏小,0.15g El Cen-tro波输入下自下而上桩的加速度时程幅值和峰值放大系数的试验值、计算值均一直有较大幅度增大;0.5g El Centro波输入下,加速度时程幅值的计算值和试验值在桩折断位置之下一直增大、至砂土层与黏土层过渡带则大大减小,加速度峰值放大系数的试验值和计算值在砂土层与黏土层过渡带突变增大、而在地表则明显减小,且较0.15g El Centro波输入下桩的峰值放大系数要偏小.     

含水层构造对抽灌水温变特性的影响

针对不同含水层构造抽灌井群地下温度场的演化规律进行实验研究,分析相同井群抽灌量和几何参数条件下,不同含水层介质的热湿运移规律及热交互影响。研究表明:含水层岩性的变化对井场热贯通时间的影响较大,对后期的热交互影响相对略小。粒块体结构较大的砂砾含水层,其井场热贯通时间明显缩短。含水层介质的分布状态对热交互影响较大,对热贯通时间的影响有大有小。对于均匀分布含水介质,各井抽灌量应尽量均匀分配,推迟热贯通发生和减弱热交互影响。对于非均匀分布含水介质,采用各井配置流量调整,可改善热湿均衡性,避免非均匀含水介质的不利影响。