甲胺与γ—丁内酯反应的热动力学研究

以甲胺和γ-丁内酯为原料可生产一种十分重要的化工试剂N-甲基吡咯烷酮.测定其反应热效应和速率常数对于化工设计和工业生产具有重要意义.本文以热导式自动量热计测定了该反应未见文献报道的摩尔焓和速率常数,为化工生产提供了有用数据.     

O（^3P）原子与丙醛和正丁醛化学反应动力学研究

我们已对O(~3p)原子和酮类分子化学反应速率常数进行了系列测定,分析讨论了羰基对O(~3p)抽提氢原子反应速率的影响,关于O(~3p)与醛类分子反应速率的测定也有报道。本文用流动微波放电-化学发光光子计数方法测定O(~3p)原子与丙醛和正丁醛化学反应速率常数及其与温度的关系,并由动力学数据对醛基中C—H键的离解能进行了讨论。     

氧原子（^3P）与环己酮反应速率常数研究

碳氢化合物被NO_x光氧化过程中会产生中间物质酮类化合物,与烷烃、烯烃不同的是,这类化合物与大气化学中感兴趣的自由基,如O、OH等的基元反应研究得不多。除有少量关于O(~3p)与丙酮反应速率常数测定的报道外,前文还报道了O(~3p)与丁酮反应速率常数的测定,并得出该反应速率常数与温度关系的Arrhenius表达式。     

甲基丙烯酸甲酯本体自由基聚合的链终止过程和终止反应参数k_t

本文报道了在ESR谱仪上用后效应技术严格测定了反应全程终止速率常数k_t,并就自由基微环境对终止反应的影响进行了讨论。     

用NMR法研究铜(Ⅱ)-氨基酸二元配合物配体交换反应动力学

采用Varian XL200超导核磁谱仪,在200.057MHz和25±0.5℃条件下,测定了水溶液中Cu(Ⅱ)分别与脯氨酸、缬氨酸、α-氨基丁酸、苏氨酸、丙氨酸和甘氨酸配合物的配体交换反应速率常数.根据NMR原理导出了实验线宽与配体交换反应速率常数之间的关系,解释了弛豫时间随配体浓度的变化关系.实验表明,交换反应速率大小顺序与氨基酸配体的空间因素一致,即随氨基酸的碳原子数增加,交换反应速率常数减少.根据实验结果提出涉及三角双锥过渡态的反应机理.     

特征参量法1: 简单级数反应的热动力学研究法

建立了测定热动力学体系冷却常数的线性拟合法和简单级数反应通用的热动力学研究法---特征参量法。导出了简单级数反应的动力学参数Kn和速率常数kn的通用计算式。应用冷却常数的线性拟合法在不同温度下测定了两个反应体系的冷却常数, 探讨了温度、浓度、介质及装样方式对冷却常数的影响。应用简单级数反应的特征参量法研究了一级、二级、三级和分数级反应的热动力学, 结果文献值吻合。讨论了热动力学体系的冷却常数对速率常数计算结果的影响。     

特征参量法1: 简单级数反应的热动力学研究法

建立了测定热动力学体系冷却常数的线性拟合法和简单级数反应通用的热动力学研究法---特征参量法。导出了简单级数反应的动力学参数Kn和速率常数kn的通用计算式。应用冷却常数的线性拟合法在不同温度下测定了两个反应体系的冷却常数, 探讨了温度、浓度、介质及装样方式对冷却常数的影响。应用简单级数反应的特征参量法研究了一级、二级、三级和分数级反应的热动力学, 结果文献值吻合。讨论了热动力学体系的冷却常数对速率常数计算结果的影响。     

异相Ziegler-Natta催化剂的活性中心多分散性(Ⅱ)——4种活性中心的聚合动力学参数

测定了络合Ⅱ型TiCl₃-Al(C₂H₅)₃催化1-辛烯聚合中不同时间的产物分子量分布,用4个Schulz-Flory“最可几”分布函数叠加,较好地拟合了实测分布,从而确定此体系有4种活性中心。从拟合及动力学测定结果确定了4种活性中心的聚合速率、浓度及链增长速率常数、链转移速率常数等,讨论了各活性中心的结构及聚合机理。     

CH(A^2△和B^2∑^-)和醇类分子碰撞过程动力学研究

本文报道用四倍频YAG激光(266nm)光解CHBr3产生电子激发态CH(A,B)自由基和测量自发辐射CH(A,B→X)的时间分辨信号的方法测定了室温(290K)下CH(A,B)被醇类分子(乙醇、异丙醇、正丁醇、异戊醇和叔戊醇)猝灭的速率常数, 实验测定的CH(A)和CH(B)猝灭速率常数k~q^A和k~q^B(单位为10^-^1^0cm^3.molecule^-^1.s^-^1)值如下(误差为线性拟合的标准偏差):此外, 还从碰撞配合物模型出发, 就醇分子中OH基对猝灭速率常数的影响作了讨论。     

乙酸乙酯皂化反应的热动力学实验

介绍基于量热法的热动力学原理。利用该方法测定了乙酸乙酯皂化反应的速率常数,并比较了该方法与电导法的优缺点。     

Reaction and kinetics in system of rare earths with p-hippurochlorophosphonazo

The beta-type reactions, in which rare earth ions react with chlorophosphonazo, reagents, are extremely sensitive and have been applied widely to determination of rare earths. The reactions and kinetic behavior of the beta-type homo- and iso-nuclear chelates of rare earth with p-hippurochlorophosphonazo (CPA-pHA) have been investigated by a spectrophotometric method. Some kinetic parameters, such as the reaction rate constants, the half lives and the activation energies, were measured. The competing reactions between lanthanoid ions forming and non-forming beta-type chelates were also studied. The effects and trends of different organic solvents on the beta-type chelates have been discussed. A reaction mechanism of beta-type chelates has been proposed.     

稀土催化体系Nd(napb)_3-AlEt_2Cl-Al(i-Bu)_3对双烯烃聚合的活性

分析了催化剂Nd(naph)_3-AlEt_2Cl-Al(i-Bu)_3三组分反应产物的组成,用动力学方法研究了其催化异戊二烯聚合的活性。催化剂各组分的配比及制备方法对其活性及利用率有显著影响。催化剂的利用率随它使用时浓度的减小而增大,最后达到恒定链终止反应由体系中过量的AlEt_2Cl吸附于活性体而发生。     

Study and analytical application of rare earth inhibition of laccase

The effect of metal ions on the laccase-catalyzed redox reaction of 5,6-dibromo-2,3-dicyanohydroquinone to 5,6-dibromo-2,3-dicyanosemiquinone was studied. The results show that rare earth ions strongly inhibited the reaction, while most of the common elements such as Ca(2+), Mg(2+), Cu(2+), Zn(2+), Al(3+) and Fe(3+), etc. had no inhibition on the reaction. Further experimental results reveal that the inhibition of lanthanum (III) on laccase activity was of the comparative type and the degree of inhibition of La(3+) on laccase activity was proportional to the concentration of La(3+). Based on this, a simple, rapid and new stopped-flow enzyme-catalyzed analytical kinetic method for determination of rare earth was proposed and applied to the determination of trace amounts of rare earth in water.     

Simultaneous Determination of Samarium and Gadolinium by a Automated Stopped-flow Analyzer

The present paper contains the reaction mechanism of the rare earth complex with 2-(2-arsenophenylazo)-7-(2, 6-dichloro-4-fluoro-phenylazo)- 1, 8-dihydroxynaphthalene-3, 6-disulfonic acid (DCF-arsenazo) studied preliminarily with a fully automated stopped-flow analyzer. A method with a high sensitivity and selectivity is proposed for the simultaneous determination of samarium and gadolinium based on the differential kinetic reaction of the rare earth complex with DCF-arsenazo. Sm and Gd in their concentrated oxides were determined with the relative errors less than 6%.     

配体交换反应速差动力学法同时测定稀土混合物的数学模型

提出了用可逆模型进行曲线拟合处理数据,并以稀土偶氮肿Ⅲ络合物与CyDTA交换反应为例作验证,结果理论曲线与实验曲线能很好地吻合,提高了用动力学法测定混合稀土的准确度。     

异戊二烯/1,2-环氧己烷嵌段共聚物的合成及其固定化酶

稀土催化剂;葡萄糖氧化酶;异戊二烯/1;2-环氧己烷嵌段共聚物的合成及其固定化酶     

Extraction of the contribution of kinetic profile for reaction of a chemical species in unknown matrices by standard addition method

A new and simple strategy is applied to resolve kinetic profile for the reaction of an analyte in unknown matrices, using standard addition method (SAM). The proposed method uses kinetic spectrophotometric data obtained by standard addition of analyte into unknown mixtures followed by the reaction of analyte with a proper reagent. The proposed method extracts kinetic profile for the reaction of an analyte by averaging the kinetic profiles obtained by subtraction of kinetic profiles after and before standard addition. The rate constant can be obtained using computational curve fitting. The performance of method was evaluated by using synthetic data as well as several experimental data sets. The proposed method can be applied to obtain kinetic profiles of the reactions in the presence of additive interference as well as multiplicative interferences. Hydroxylation reaction of diphenylcarbazide (DPCI) in the presence of diphenylcarbazone (DPCO) as a real system at various pHs was also studied by the present method. The rate constant and the order of the hydroxylation reaction were determined from extracted kinetic profiles.     

La(NO3)3和Pr(NO3)3对高岭石脱羟基动力学的影响

采用热重和微商热重(TG/DTA)综合热分析技术在不同升温速率下研究了掺入La(NO₃)₃和Pr(NO₃)₃的高岭石的热分解过程, 利用Coats-Redfern积分法和Achar微分法对热分析实验数据进行动力学计算, 得到了高岭石脱羟基反应过程中的控制机理函数、 活化能和指前因子等动力学参数; 分析了2种稀土掺入对高岭石脱羟基过程动力学参数的影响, 并用Ozawa法对活化能进行了验证. 结果表明, 未掺稀土和掺入Pr(NO₃)₃的高岭石的脱羟基反应过程均受化学反应模型F₃控制, 反应的活化能分别为307.94和282.86 kJ/mol, 指前因子lnA的值分别为47.8980和44.1718; 掺入La(NO₃)₃的高岭石脱羟基反应过程控制机理函数发生改变, 受化学反应模型F₂控制, 反应活化能为196.02 kJ/mol, 指前因子lnA的值为29.5551. 与未掺稀土的高岭石对比, 掺入Pr(NO₃)₃后活化能和指前因子略有降低; 而掺入La(NO₃)₃后则显著降低, 分别降低了36.34%和38.30%. 采用Ozawa法验证得到的活化能与Coats-Redfern积分法和Achar微分法结果一致.     

稀土化合物参与的聚丙烯反应挤出接枝马来酸酐

将多种稀土化合物用于等规聚丙烯(iPP)与马来酸酐(MAH)的接枝反应, 对接枝共聚物的结构、 接枝率和加工行为等进行了表征和研究. 结果表明, 稀土氧化物CeO2和Nd2O3的加入促进了iPP熔体接枝MAH的反应, 与未加入稀土化合物的接枝体系相比, MAH单体接枝率最大值分别提高了14%和25%, 同时接枝共聚物的熔体流动速率(MFR)也分别增大了34%和56%. 根据实验条件下接枝共聚物的MFR与MAH单体接枝率间的关系, 并结合熔体接枝反应机理, 提出了采用MFR来表征接枝率的方法, 并建立了工作曲线. 同时, 对不同稀土化合物抑制或促进熔体接枝反应发生的机理进行了初步探讨.     

对甲基苯磺酰化蛋氨酸La(Ⅲ)配合物的非等温热分解动力学研究

合成甲基苯磺酰化蛋氨酸配合物[La(p-methBsMeH)3],并通过元素分析、红外光谱、X射线粉末衍射、TD-DTG及摩尔电导等对其结构进行了表征,在非等温条件下,采用Achar的微分法和Coats-Redfem的积分法拟合出配合物的热分解动力学方程、相应的动力学参数及活化熵变△S≠、活化吉布斯自由能变△G≠和活化...