反应速率

For intramolecular electron transfer reactions in solution,the fluctuations of the intramolecular vibrational modes are much faster than that of solvent mode.Thus,the reaction-diffusion equation is commonly used to describe the motion of solvent,with a sink function to treat the vibrational high-frequency mode.Based on this theory-so -called the Sumi-Marcus theory,we proposed an imaginary-time split operator approach to solve the reaction-diffusion equation.The approach is applied to evaluate the intermolecular ET rate between oxazine 1 and N,N-dimethlaniline.By measuring the two average survival times of the donor state probability and the rate constant in long time limit,the full kinetics of the ET is revealed with a variety of sink functions.

对于扩散控制的溶液中的电子转移反应，分子内振动模的运动比溶剂运动快很多，Sumi-Marcus理论提出用反应扩散方程(reaction-diffusion equation)处理溶剂的扩散运动，而分子内的振动用sink函数来表示，我们基于此理论发展了用虚时间分裂算符的方法(imaginary-time Split operator approach)解反应扩散方程，并将其应用于嗪1(oxazine 1，OX1)和N，N-二甲基苯胺分子之间的电子转移反应，Sink函数采用几种不同的微扰表达式，通过计算得到给体几率衰减的两种平均速率和长时间极限下的速率常数，揭示了该体系电子转移过程中的一些动力学性质。

At present,the rate laws and reaction mechanisms of pyrite oxidation,pyrite and chalcopyrite formation,uraninite and magnetite dissolution in aqueous solutions are mainly studied,and it is discovered that (1)oxidation rate of pyrite controlled by surface reaction assume fractional dependence on Fe3+ and O2 molalities in acid solutions;(2)Pyrite cannot nucleate directly from solutions below 300 ℃,it can only form initially through sulfidation of a FeS precursor. The rate equation of reaction between FeS and H2S to form pyrite is of the second order;(3)Chalcopyrite is formed by reactions of pyrrhotite or pyrite with Cu2+,the former proceeds via a series of mediate metastable phases of Cu-Fe sulfide,whereas the rate equation of the latter is apparently of the first order which is controlled by surface reaction;(4)The nonlinear behavior of magnetite dissolution at acid pH can be represented by a shrinking core model coupling with surface reaction and diffusion transport.

目前主要研究了水溶液中黄铁矿氧化、黄铁矿和黄铜矿形成、晶质铀矿和磁铁矿溶解的速率定律和反应机理，发现：(1)酸性溶液中黄铁矿的氧化速率对Fe3+和O2浓度呈分数依赖并受表面反应的控制；(2)低于300 ℃时黄铁矿不能从溶液中直接成核，而需初始地通过FeS先驱物的硫化生成，FeS与H2S反应形成黄铁矿的速率方程为二级；(3)磁黄铁矿或黄铁矿与Cu2+反应均可形成黄铜矿，前者经历了一系列准稳的Cu-Fe硫化物的中间物，后者的速率方程为表观一级并受表面反应的控制；(4)酸性pH时磁铁矿的非线性溶解行为可采用表面反应扩散输运耦合的收缩核模型来描述。

The effects of the surfactants, trioctyl phosphine oxide, sodium dodecyl sulfonate and hexadecyl trimethyl ammonium bromide, on the extraction rate of Co^2^+ were investigated. The acceleration in the kinetics in contributed to the associated molecule~2 TOPO taking part in the extraction process directly. The decrement effects of SDS or CTMAB on the rate of extraction kinetics of Co^2^+ with HDEHP were also observed, which caused by the adsorption of molecules of SDS or CTMAB on the interface and decreased the interfacial adsorption amount of HDEHP. In addition, the extraction rate was reduced by a bigger margin in HDEHP-SDS system. This can be explained in terms of the formation of an electric field at the interface.

研究体系中加入不同表面活性剂所引起萃取速率的不同改变：三辛基氧化膦因与HDEHP形成可萃取的Co^2^+活性分子缔合物，降低了萃取过程活化能而使反应加速；十二烷基磺酸钠和十六烷基三甲基溴化铵因占据发生萃取反应的界面区，减小了HDEHP与Co^2^+反应的机会而使反应减速； SDS还因其在界面形成较强的负电场，造成Co^2^+的附加势能而使萃取速率有更大幅度的降低。

Previous results have established a rate of interaction between WIMPs and nuclei that varies depending on WIMP mass.

以前的结果已经确立了一个依赖于WIMP质量的WIMPs跟原子核之间的反应速率。

The on-line reaction kinetics of RIM polymerization of PU/VER SINs has been monitored by using a mini-RIM machine interfaced with FTIR During the course of synthesis, the two pairs of reactants interfere with each other in PU/VERA SIN system, although they follow different polymerization mechanisms and the possibility of inter-component chemical binding may be neglected (secondary hydroxyl groups of VERA capped).

在对机械搅拌混合物料PU／VER SIN体系进行了DSC、FTIR聚合反应动力学研究的基础上，本文首次利用第一台国产微型RIM机成功地实现了RIM PU/VER SIN体系合成时的FTIR在线聚合反应动力学测量。虽然PU、VERA网络的生成遵循不同的聚合反应机理（逐步缩聚反应、自由基共聚反应），并且两网络间的化学键合作用可以忽略（VERA为封闭仲羟基的VER），但合成PU/VERA SIN时两组份的相互作用不容忽视，两网络的生成速率均低于同样温度下纯网络的生成速率。

The result will provide afundamental basis for industrial design.Firstly,based on the assumptions that the reaction generating mono-ester was controlled by the solution rate of pentaerythritol,that di-ester conversed to tri-ester rapidly and that all the reverse reactions and side reactions were omitted,the equations of reaction kinetics were obtained.

具体工作如下：(1)基于生成一酯的反应受季戊四醇溶解速率控制、二酯迅速转化为三酯和忽略所有逆反应及其它副反应的假设基础上，建立了酯交换反应的反应动力学方程，获得了不同温度下的动力学常数和速率常数的指前因子及活化能。

E. , a relatively fast second-order reaction followed by a very slow first-order one.

这两个阶段的反应速率都是TEMPO-16 2。

The copolysiloxane PSII3A the raio of fed monomers (M1/M2)=1/9, M1 is 4-undecylen-

比较了异构反应速率和异构转换率，以聚硅氧烷共聚物PSII3A[侧基比(M1/M2)=1/9， M1是对十一烯酰基偶氮苯， M2是对十一烯酰氧对氧基苯酯]为最佳。

Rocket engine ; plasma ; assisted combustion ; Gibbs free energy ; reac tion speed

火箭发动机；等离子体；助燃；吉布斯自由能；反应速率

After that, the main aim of this study is to determine the ratio between the reaction rates in a continuous stirred tank reactor rS(CSTR and that in a packed-bed bioreactor with immobilised biomass rS

在那之后，主要的目的是为了确定该研究的反应速率之间的比例在连续搅拌釜式反应器，寻在填充床生物反应器和固定生物量

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。