低浓度苯胺在大孔树脂上吸附的动力学研究     

李湘  李忠 《西江大学学报》2006,27(2):32-35,49

测定了水相中苯胺在NKA—Ⅱ和AB-8这2种大孔吸附树脂上的吸附等温线和吸附速率曲线．结果表明：极性的NKA—Ⅱ对苯胺的吸附量要高于弱极性的AB-8对苯胺的吸附量，苯胺在2种吸附树脂上的相平衡关系符合Freundlich方程；苯胺在NKA—Ⅱ和AB-8上的吸附受腱扩散控制．动态吸附实验和模拟结果表明：模拟透过曲线与实验透过曲线比较吻合，所建立的模型能够较好地描述苯胺在2种大孔吸附树脂填充柱上的吸附透过过程．  相似文献   

Recovery of Dilute Acetic Acid by Catalytic Distillation Using NKC-9 as Catalyst     

张志刚  李晓峰  徐世民  李鑫钢 《天津大学学报(英文版)》2006,12(4):264-270

The reaction kinetics of dilute acetic acid with methanol using NKC-9 as catalyst was studied at temperatures of 308 K, 318 K, 323 K, 328 K. The kinetic model based on Langmuir-Hinshel-wood rate model was derived and the activation energy was 6.13×104 kJ/kmol. The experiment of recovery of dilute acetic acid was conducted in a packed bed catalytic distillation column. The optimal process parameters and operational conditions determined to make up to 85.9% conversion of acetic acid are as follows:the height of catalyst bed is 1 100 mm, reflux ratio is 4:1, and the ratio of methanol to acetic acid is 2:1. The method can be used as a guide in industrial scale recovery of 15%-30% dilute acetic acid.  相似文献   

Polymerization of methyl methacrylate with ethylene bridged heterodinuclear metallocene of samarium and titanium-study on synergism and kinetics     

Sun Jun-quan  Pan Zhi-da  Hu Wei-qiu  Yang Shi-lin 《浙江大学学报(A卷英文版)》2001,2(4):366-371

Comparison of MMA polymerization results with samarocene chloride, titanocene chloride and the title heterodinuclear (Sm−Ti) catalyst, respectively, showed synergism in the Sm-Ligand-Ti system, which obviously influenced the polymerization behaviors, for example, of yeilding higher activity and higher molecular weight polymer. Kinetic studies on polymerization of MMA with ethylene bridged samarocene and titanocene chloride/Al(i-Bu)₃ showed that the polymerization rate was first-order on the catalyst concentration, and 1.9-order on the monomer. The overall activation energy measured was 52.8 kJ/mol. Project supported by NSFC (No. 20074028), and SINOPEC(X598037).  相似文献   

Adsorption of Cu^2 ＋, Zn^2＋ and Cd^2＋ on Bacillus subtilis     

刘丽艳李鑫钢  唐国武孙津生 《天津大学学报(英文版)》2006,12(2):104-108

A process of biosorption of Cu2 , Zn2 and Cd2 on Bacillus subtilis was investigated. The experiments show that the process of biosorption is quite fast. The maximum adsorption was reached after 5 min and hardly changed with time. The experimental data was analyzed using four sorption kinetic models: the pseudo-first-order, the Ritchie second-order, the modified second-order and the Elovich equations, which helped to determine the best-fit equation for the sorption of metal ions onto biomass. The results show that both the Ritchie second-order and modified second-order equations can fit the experimental data. The Langmuir model is able to accurately describe adsorption of Cu2 and Zn2 on B. subtilis. The experimental data points of adsorption Cd2 and Zn2 on B. subtilis are described by Freundlich isotherms model.  相似文献   

Investigation on Crystallization Kinetics of Zr-AI-Based Bulk Amorphous Alloys     

王国明李维火  方守狮华勤 肖学山 《上海大学学报(英文版)》2005,9(1):78-81

Zr65Al10Ni10Cu15, Zr52.5Al10Ni10Cu15Be12.5 and Zr52.5Al10Ni14.6 Cu17.9Ti5bulk amorphous alloys were prepared by copper mould casting. The crystallization kinetics was measured by differential scanning calorimeter(DSC) with different heating rates, and the activation energy was calculated using Kissinger equation. The relationship between thermal stability and rate constant of crystallization reaction is discussed on the view of crystallization kinetics, and the effect of small atom Beryllium on thermal stability of bulk amorphous alloys is also studied.  相似文献   

SAP材料的接枝反应动力学实验研究   总被引：1，自引：0，他引：1  

李丽  刘东  曹冲  梁敏 《实验室研究与探索》2007,26(6):26-29

对淀粉接枝丙烯酸所得接枝共聚物及接枝侧链物进行分离提纯和分析测试,确定了其接枝效率并表征了淀粉及其接枝物的形态结构;通过分别测定接枝共聚反应速率与淀粉、单体、引发剂浓度的关系曲线,确定了该接枝共聚反应的速率关系式;推算出了反应的表观活化能。  相似文献   

Fe(Ⅲ)-H2O2-甲基紫体系催化褪色光度法测定痕量铁(Ⅲ)     

鲁绪会  柯敏 《安康学院学报》2003,15(1):66-69

研究了Fe(Ⅲ)在酸性介质中催化双氧水甲基紫体系的氧化褪色反应,提出一种测定痕量Fe(Ⅲ)的新方法,体系的最大吸收波长为566nm,Fe(Ⅲ)含量在4～12μg*ml-1符合朗伯-比耳定律,回归方程为ΔA=0.00775C+0.05,相关系数γ=0.9930,最低检出限为2.75×10-7g*ml-1,相对标准偏差为1.83%,结果令人满意.  相似文献   

聚合物结晶动力学     

杨海  刘天西 《南阳师范学院学报》2007,6(12):37-40,51

总结了几种常见的用于描述聚合物等温及非等温结晶行为的动力学方法,并结合具体的应用实例对这些动力学模型的优缺点等方面进行了简单的讨论。  相似文献   

基于蒙特卡罗模拟的不同聚合温度下的丙烯聚合动力学研究   总被引：4，自引：0，他引：4  

罗正鸿  黄凯  曹志凯 《东南大学学报》2006,22(1):117-120

在不考虑其他杂质参与聚合反应的情况下,并基于已有对丙烯聚合反应过程的普适化认识,提出了一个普适的丙烯聚合反应机理(基元反应).在已有的丙烯聚合反应机理基础上,为了证实该聚合反应过程总活性基是否满足“稳态假定”以及考察聚合反应温度对聚合过程的影响,采用蒙特卡罗模拟方法研究了传统Ziegler-Natta催化剂催化下的丙烯聚合动力学.模拟得到的总活性基数目在丙烯聚合初期快速增加到峰值,然后随聚合反应的进行保持恒定,证实了丙烯聚合过程中总活性基符合稳态假定.同时,模拟得到了聚合温度对丙烯聚合过程的转化率、分子量的影响.模拟结果表明:在聚合过程中,丙烯单体的消耗速率随聚合温度升高而增加;不同聚合温度下的数均聚合度峰值相同,但随温度增加,数均聚合度峰值来得早;随聚合温度增加,数均分子量减少,分子量分布变宽.  相似文献   

Improved elastase production by Bacillus sp. EL31410─further optimization and kinetics studies of culture medium for batch fermentation     

何国庆  陈启和  琚晓捷  石乃冬 《Journal of Zhejiang University. Science. B》2004,(2)

INTRODUCTION Elastase is an enzyme that attacks and solubi-lizes elastin. As elastase can degrade elastin (Mori-hara, 1967) that other proteases cannot; it has broad applications in medical therapy, food processing and daily use chemicals industry. Considerable eff- orts were made to screen the elastase-producing strains, to study its pathogen effect and its charac-terizations (Tsuzuki and Oka, 1965; Tsai et al., 1988; Sharon et al., 1997; Ozaki and Shiio, 1975). Shiio, 1975). Reporte…  相似文献