还原

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。

The facile methods for selective generation of〓(n= 1, 2, 3) were reported.

系统地研究了〓的还原反应，初步总结了一些还原〓的规律。2、开发了水相化学方法选择性地合成〓(n=l，2，3)负离子。

The high oxidation-reduction potential and lack of reduced conditions permits aerobes and facultative anaerobes to contribute to the decomposition processes.

高氧化还原电势和缺乏还原条件，使得好氧菌和兼性厌氧菌进行分解或腐化过程。

The subsequent signal recovered from the samples will not contain the high frequency component of the original signal and will display a false low frequency signal.

以低于信号中最高频率两倍的频率进行信号取样时出现的一种效应，即当由取样状态还原时，还原后的信号将不再含有原来信号中的高频成分，并将显示出虚假的低频信号。

Signal recovered from the samples will not contain the high frequency component of the original signal and will display a false low frequency signal.

以低于信号中最高频率两倍的频率进行信号取样时出现的一种效应，即当由取样状态还原时，还原后的信号将不再含有原来信号中的高频成分，并将显示出虚假的低频信号。

According to the electrochemistry mixed potential theory, the linear sweep voltammagram method is used to study the cathod and anode processes of the stabilizers. The results show that α-α' dipyridyl can decrease the deposition velocity by inhibit the anodic oxidation of formaldehyde, and potassium ferrocyanide can stabilizing the bath by inhibit the deoxidation of Cu~(2+).

根据电化学混合电位理论，用线性伏安法研究表明，α-αˊ联吡啶通过有效地抑制甲醛的阳极氧化来抑制沉铜速率；而亚铁氰化钾主要通过抑制Cu~(2+)的还原峰电流来阻碍Cu~(2+)的还原析出，但宏观的对化学镀铜镀速的影响不大。

For the system of industrial test for treatling 200m 3/d wastewater, the removal rate of COD reached to over 90%, and the H 2S in firedamp was finally recovered as the by-product of sulfur.

这些物质在厌氧环境下，通过硫酸还原菌的作用，产生大量硫的还原产物存在于消化液中，一方面引起设备的腐蚀，使水质产生异味；当这些物质在消化器中积累到一定浓度，就对甲烷菌产生严重的抑制作用。

The results show that the periodic average yield of acrylonitrile under any forced periodic oscillation of oxygen concentration among this experimental conditions,thus obtained could higher than that under the steady-state condition.

而为完成整个氧化还原循环过程，气相氧分子就必须在不同丙烯吸附中心的再氧化中心上吸附，获得电子，解离后扩散进入催化剂中的阴离子孔穴，如图1所示。从该机理可知，反应气氛中的氧烯比大小对催化剂表面的氧化还原反应过程的循环有重大影响。

When TiP2 powder and carbon grain are mixed and pressed into globosity, the reduction is either gas-solid or solid-solid reaction.

升高温度有利于还原进行，钛氧化物的开始还原温度随气相中的CO分压降低而降低。

Our spectroelectrochemistry studies confirms that it is from the semiquinone species that the glycoside elimination occurs.

由于ADM在体内往往需要还原激活，对ADM的还原反应的研究更引起人们的关注。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。