活性中心

The synthesis of flame retardant for cotton with a new catalytic system ;2. Advances in the catalytic system s for synthesis of terephthalic acid via oxidation of paraxylene

在不同二苯基二甲氧基硅烷用量、聚合温度及聚合时间等条件下，考察DDS对α-烯烃聚合载体型催化体系活性中心的影响。

1 To mimic the active centers of tyrosinate iron enzymes whichcontain phenolate donors, new tripodal ligand, N-(2-hydroxybenzyl)-N, N-bis(2-benzimidazolymethyl) aminewhich contain imidazoleand phendate groups were designed and synthesized and its iron com-plexes 〓(2)(where Mim=N-Methylimidazole) and Fe 〓(3) were prepared andcharacterized by various spectroscopic methods.

1.1 为了模拟酪酸铁酶活性中心，设计并合成了含有酚羟基和苯骈咪唑基四齿配体N，N-(2-羟基苯)-N，N-二氨，并合成它的铁配合物：Fe〓、Fe〓〓(2)和Fe〓，并经各种谱学手段表征了这些铁配合物。

But thefunctions of SOD-like genes were not approved.We cloned SOD gene fromBombyx mori Nuclear Polyhedrosis Virus genome by PCR.

我们克隆了家蚕杆状病毒的sod基因，测定其核苷酸序列与人源的SOD1基因同源性为56％，其中铜、锌离子的结合位点和酶活性中心位点相当保守。

Shows that the same enzyme or enzymes of similar function, its active site near the ...

可见同一酶或功能相近的酶，其活性中心附近的。。。

Being combining with products distribution in styrene oxidation, we propose the styrene epoxidation carry out with Ti metallacyclo intermediates, And at the same time Ti-ZSM-5 have properties both catalytic epoxidation and acid-catalysis, namely the skeletal Ti can catalyze styrene epoxidation to styrene oxide and the skeletal Ti and Al can provide Lewis acid site to cause the rearrangement of styrene oxide to phenylacetaldehyde rapidly, the solvolysis to glycols and the cleavage of C=C double bond. Ti-ZSM-5 can also provide Bronsted acid site simultaneously, which is also catalytic center for the solvolysis to glycols.

同时结合Ti-ZSM-5催化选择性氧化苯乙烯反应的产物分布结果，提出苯乙烯环氧化反应可能是通过金属有机环机理进行；Ti-ZSM-5同时具有催化环氧化和酸催化两种功能，其骨架钛可催化苯乙烯环氧化生成环氧苯乙烷，而骨架钛和骨架铝等可提供Lewis酸位使环氧苯乙烷迅速发生重排生成苯乙醛从而使其成为反应的主要产物，同时还可发生加成以及碳碳键的裂解等副反应：Ti-ZSM-5也提供Bronsted酸位，它也是生成加成产物的活性中心。

Forms a thioether bond with the sulfhydryl group in the active center of the enzyme.

与酶活性中心的巯基形成硫醚键。

FT-IR and UV-vis spectra indicated the existence of tetrahedrally coordinated Ti atoms, which may act as active sites for epoxidation of olefin.

FT-IR和UV-vis结果说明该沸石骨架在存在四配位钛，从而有可能成为催化烯烃环氧化反应的活性中心。

Thenard(1811), the discoverer of hydrogen peroxide, expected that its degradation in living tissue is performed by a special substance, which Schonbein (1863) identified as a certain kind of 'ferment'. Loew (1901) was the first who named this H2O2-degrading enzyme catalase, but it took further 22 years until Warburg (1923) demonstrated that the active center of catalase contains iron, as concluded from the characteristic inhibition with cyanide.

过氧化氢的发现者Thenard ，希望活体组织中过氧化氢的降解是由一种特殊物质引起的，Schonbein定义这种特殊物质为某种酵种，Loew是第一个定义为过氧化氢降解酶，22年后Warburg 证明过氧化氢酶的活性中心含有Fe，正如从已知氰化物的特性得到结论。1927年，WIeland提出了一个简单的细胞过中氧化氢酶的解释。

Characterization of the catalysts indicates that the Cu species is more stable in the VCe1-xCux-NaCl than those in the supported catalysts, and the reduced copper species with low valance might be the active sites.

通过各种表征手段表明，在复合氧化物中铜物种能够以孤立的状态稳定存在，经过还原后，还原态的低价态铜物种可能是反应的活性中心。

Eliminating radical in human body by taking the alimental organism with antioxidant capabilities is beneficial to the health and can make us long life.

本文主要考察食疗型生物体中生物高分子活性中心元素分布与其抗氧化功能之间的关系。

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％。