Degradation of p-nitrotoluene by 03/H2 02 process and oxidation mechanism

The degradation of p-nitrotoluene by O2/H2O2 process in a bubble contact column was investigated.Effects of the molar ratio of hydrogen peroxide to ozone, pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2 O2/O3 molar ratio for the degradation of p-nitrotoluene was around O. 6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-metbyl-2-nitrophenol, 2-methy1-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl) -2-nitro phenol, acetic acid, 2-methylpropanc diacid and 2-(hydroxylmethyl) propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydrexy intermediate pathway. Then unstable polybydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.     

Degradation of p-nitrotoluene by O3/H2O2 process and oxidation mechanism

The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.     

一种多元复合地基复合模量的计算方法

多元复合地基的沉降计算依赖于其复合模量的取值.目前多元复合地基复合模量计算均未考虑桩对桩间土的侧向挤密作用,因而其沉降计算结果与实际值相差较大.而考虑桩体与桩间土的侧向挤压作用,依据线弹性变形理论,推求的多元复合地基的复合模量公式应用于工程实例,结果表明,该方法是合理可行的,并且存在着参数易于确定、方法简便、机理清楚的特点.     

HPFL加固空斗墙砌体抗压强度试验研究

高性能水泥复合砂浆钢筋网薄层(HPFL)加固法是一种新型的结构加固补强技术.通过2组对比试件和3组加固试件在分级加载下的轴压试验,研究了HPFL对空斗墙砌体的抗压加固效果.实验结果表明,单面加固极限承载力提高41.7%,双面加固不仅极限承载力提高50%~53.8%,开裂荷载也提高约21.3%~27%.笔者通过实验数据拟合了空斗墙受压应力-应变曲线,并提出HPFL加固空斗墙砌体承载力计算方法,供加固设计时参考.     

新型分子筛脱除钙离子的热力学研究

实验测定了新型分子筛对钙离子的全交换容量及25℃、50℃、75℃下离子交换平衡数据.依据实验数据,绘制了Na+-Ca2+离子交换等温线以及Kielland图,计算出了该过程的焓变化,吉布斯自由能和熵变化.研究表明该新型分子筛Na+-Ca2+离子交换过程可用Langmuir吸附等温式很好的描述,且该过程为吸热反应,可自发进行,高温有利于钙离子的交换.     

一种双游程编码的测试数据压缩方案

SOC芯片测试中一个主要的挑战就是处理大量的测试数据.为了减少芯片测试中的测试数据,提出了一种双游程的编码方案,采用变长到变长的编码方式对0游程和1游程进行编码.该算法在编码时同时考虑0游程和1游程,大大减少了测试数据中短游程的数量,同时文中给出了一种基于有限状态机的解压缩算法的实现方案.理论分析和实验结果证明该方案具有高压缩率、硬件实现简单等特点.     

亲水型温敏凝胶聚合物的制备与性能分析

温敏高分子材料因其对温度具有敏感性而被应用于温控开关及药物控温释放等领域.本文以N-异丙基丙烯酰胺(NIPAm)、甲基丙烯酰胺(MAm)作为单体,过硫酸钾作为引发剂,采用N,N’-亚甲基双丙烯酰胺(BIS)作为交联剂,制备了亲水型温敏凝胶聚合物,并研究了两种单体组分的质量分数比及交联剂的用量对所制备的凝胶聚合物的低临界溶液温度(LCST)、溶胀率和保水率的影响.研究结果表明:合成的N-异丙基丙烯酰胺与甲基丙烯酰胺的凝胶聚合物(简写为P(NI-PAm-co-MAm))的低临界溶液温度(LCST)随着凝胶聚合物体系中亲水单体比例的增加而升高;交联剂含量越多,则凝胶聚合物的溶胀率越小,而保水率增大;凝胶聚合物的亲水单体比例增加,则凝胶聚合物的溶胀率和保水率均增大.     

大学生创业素质培养的研究与实践

推进高等学校创新创业教育和促进大学生自主创业工作是落实党的建设创新型国家,以创业带动就业发展战略的重大举措。经济管理学院根据吉林化工学院人才培养方案的总体要求,组建创业教育教研室,从理论教学和实践教学等方面探索培养学生创业素质的途径,初见成效。     

GPS的低噪声放大器的设计

论述应用于GPS的低噪声放大器的设计原理,并通过ADS仿真软件,设计出低噪声放大器。给出噪声系数、增益和输入端匹配的仿真结果。通过优化,可以使得噪声系数达到1.2以下、增益值达到30dB以上的指标。     

变螺距螺纹数车编程

变螺距螺纹在一些行业的用途极其广泛,数控车床上车削变螺距螺纹,要解决的关键问题之一是加工程序的编写。文章以西门子802D数车系统为例,阐述变螺距螺纹的数控加工原理及参数编程方法,并给出原程序,为生产中解决变螺距螺纹的加工提供参考依据。