二分子

On the basis of the kinetic equation of substrate reaction in the presence of urea or guanidine hydrochloride, all microscopic kinetic constants for the free enzyme and enzyme-substrate binary and ternary complexes have been determined. The results of the present studies indicate that:①In the presence of urea or guanidine hydrochloride, enzyme-substrate complexes lose their activity less rapidly than the free enzyme. Therefore, both substrates, NADPH and 7, 8-dihydrofolate, protect dihydrofolate reductase against inactivation.②The denaturation of dihydrofolate reductase by urea follows single-phase kinetics, and changes in enzyme activity and tertiary structure proceed simultaneously in the unfolding process, so it may be an"all or none"process.③The GdnHCl-induced unfolding of the dihydrofolate shows a biphasic transition, while the change in the enzyme activity is a single exponential process. The rate constant of inactivation is consistent with that of the fast conformational change. Therefore, the kinetic intermediate of protein unfolding should be a partially folded and inactive form.

我们根据在脲或盐酸胍存在下的底物反应动力学方程求得游离酶和酶底物二元、三元复合物的微观动力学常数，结果表明：①酶-底物二元、三元复合物的失活速度明显慢于游离酶，说明两个底物二氢叶酸和NADPH对酶的失活都具有一定程度的保护作用；②在脲作用下，酶的失活和构象变化均为单指数项过程，而且酶的活力丧失和三级结构变化是同时发生的，说明二氢叶酸还原酶的脲变性可能是一个"全或无"的两态过程；③在盐酸胍作用下，酶的构象变化为两相过程，而失活则是单指数项过程，酶分子构象变化的快相速度常数与失活速度常数基本一致，因此我们认为二氢叶酸还原酶的盐酸胍变性过程中存在一个没有活力、但仍具备一定空间结构的变性中间体。

In the conformation change process, the second hyperpolarizability values of system and for singlet are negative system (a of 45° and 135° with the exception, and less than the absolute value of all triplets. The second hyperpolarizability values of system for singlet and triplet states are positive and in molecular close plane configuration time, the value of triplet is greater than that of the singlet.

在构象变化过程中，体系和单重态的二阶超极化率均为负值体系(a的45°和135°除外，且绝对值都小于三重态的二阶超极化率值，体系的单三重态二阶超极化率值均为正值，且在分子接近平面构型时，三重态的γ值大于单重态。

The rest denote sound break down, it be called rest and shown as '0' in the music book. Rest can be disport as note full-rest, half-rest quarter rest, eight rest and sixteen rest.

二分之二拍 2/2 2/2 beat 四分子二拍 2/4 2/4 beat 四分之三拍 3/4 3/4 beat 四分之四拍 4/4 4/4 beat 八分之三拍 3/8 3/8 beat 八分之六拍 6/8 6/8 beat 八分之十二拍 12/8 12/8 beat 三、休止符rest 表示声音停顿的符号，叫休止符，用"0"来表示休止符和音符一样可分为：全休止符，二分休止符，四分休止符，八分休止符和十六分休止符。

The excited-state intramolecular proton transfer tautomerism reaction of 6-methyl-4-hydroxy pyri-midine monomers and dimmers was investigated by the ab initio method with the self-consistent reaction field with Tomas's polarized continuum mode and CIS theories at HF level on the basis of 6-311+G* and 6-31G basis set. By studying the potential energy surface, it was found that the monomer's ground-state proton transfer process together with the excited-state proton transfer process is a molecular system of four energy level, but dimmers were not, which can be used to explain the fact that UV-visible absorption and fluorescence spectra of monomer and dimers all corresponded to quinoid.

采用 ab initio HF理论的组态相关CIS方法和连续溶剂模型PCM，分别在6-311+G*和6-31G水平上研究了6-甲基-4-羟基嘧啶单体及二聚体激发态质子转移的异构化反应；对其反应势能面的研究发现，单体基态和激发态的异构化反应一起可以形成四能级的分子电子体系，而二聚体的却不能，由此解释了单体和二聚体的紫外吸收光谱和荧光发射光谱均对应于酮式构型的原因。

Their adsorption rate on the molecular sieve catalysts surface and the stability of their carbonium ions were then obtained based on the molecular simulation on these molecules from their dipole moment, 2-dimensional electrostatic potential energy contours and 3-dimensional electrostatic potential energy isosurface.

采用半经验的AM1量子化学计算方法和静态理论，分别考察了噻吩、 3 甲基噻吩和 2 ，5 二甲基噻吩分子结构特性的不同，从偶极矩、各自垂直于芳香环平面的二维电势能分布曲线和整个分子周围三维电势能分布情况等方面分析了它们在分子筛催化剂表面吸附速度的快慢和生成正碳离子稳定性的高低，进一步比较了噻吩及其衍生物所生成的正碳离子进一步反应的能量变化，从而可判断噻吩及其衍生物裂化脱硫速度的快慢，噻吩及其衍生物裂化脱硫的速度由大到小分别为：2 ，5 二甲基噻吩、 3 甲基噻吩、噻吩。

An unprecedented combination of photochromism and solvatochromism for a 1,2-bis cyclopentene derivative,1,2-bis(2-methyl-5-formyl-thien-3-yl) perfluorocyclopentene,is observed:1 BMFTP,dissolved in the alcohols,exhibits the largest positive solvatochromic shift in wavelength witnessed to date.

我们发现了醛基二芳烯BMFTP的溶剂变色效应：1在醇类溶剂中，醛基二芳烯分子闭环态吸收波长将会发生显著红移；2在不同溶剂中，醛基二芳烯闭环态吸收波长不同。

A small molecule core (TMP-SK3)with three terminal carboxyl groups was synthesized successfully by the reaction of 1,1,1-trihydroxymethylpropane with the excessive sebacic acid diacetic anhydride.

以1，1，1-三羟甲基丙烷与过量癸二酸二乙酸酐反应，制得了端羧基的三官能度小分子核三癸二酸三羟甲基丙烷酯（TMP-SK3）。

The polyetherurethane was synthesized by one-step method for cosmetic applications by coupling poly(PTMG,Mn=2000) and poly(PEO,Mn=2000) with 4,4'-diphenylmethane diisocyanate.

聚醚型聚氨酯用于化妆品中，由聚四亚甲基醚二醇和聚环氧乙烷与4，4-二苯甲烷二异氰酸酯采用一步法合成，结果表明PEU暴露在60℃酒精/水(80/20，体积比)溶液中放置4周后发生降解，PEU发生变质，其相对分子质量、粘度和机械性能都发生改变。

The mechanism of dioxygen oxidation of 4-nitrotoluene-2-sulfonic acid to 4,4'-dinitrostilbene-2,2'-disulfonic acid in alkali solution under mild condition was investigated.

探讨了在温和条件下在碱的水溶液中氧气液相氧化 4-硝基甲苯- 2 -磺酸制取 4，4'-二硝基二苯乙烯- 2 ，2 '-二磺酸的反应机理，发现 4-硝基甲苯- 2 -磺酸在碱作用下发生离子化生成 4-硝基- 2 -磺酸基苄基阴离子，然后被活化的分子氧氧化成 4-硝基- 2 -磺酸基苄基自由基是反应的关键步骤。

When Ni〓 was equatorially coordinated by four nitrogen atoms from the same amine ligands such as ethylenediamine and N-methylethylenediamine, arenedisulfonates did not axially coordinated to Ni〓.

Ni〓与同样的胺配体（如乙二胺、N-甲基乙二胺）的四个氮原子在赤道平面配位后，芳烃二磺酸根离子并没有在轴向与Ni〓配位，水分子仍然占据轴向的位置。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。