酸基

And the ability of antioxidant of polyhydroxy benzamides don't have too many differences with Trolox (IC50 =13.90 μg/ml), the substition of hydroxy group at amino benzene ring doesn't affect the whole ability of antioxidant apparently, but while the single hydroxy group at carboxylic acid benzene ring, they are apparently decrease to scavenge the ability of free radical, as a result, the hydroxy at amino benzene ring substitutes its function, without the hydroxy group, the ability of antioxidant is worst, but it upgrades its function while the hydroxy and amino are in the ortho-position or para-position.

而当多酚醯胺化合物其抗氧化能力与Trolox差不多时(IC50 =13.90 μg/ml)，胺基苯环上之羟基取代对整体抗氧化能力影响不明显，但在羧酸苯环上具单羟基时，其清除自由基能力明显下降，使得胺基苯环上羟基取代发挥了影响力，无羟基取代时，抗氧化能力最差，而羟基与胺基互为邻位或是对位时较间位有提升效果。

In this paper, 4-4-(trifluoromethoxy benzoyl cyclohexyl-3, 5-diaminobenzoate with a large branch chain, pyromellitic dianhydride and 4-(4-aminobenzyl) benzenamine were used to synthesize polyimides. The effect of monomer charge order on pretilt angle was investigated for the first time when PIs were used as LC alignment layer, and the effect of diamine mole ratio on pretilt angle was studied. The thermal stability of the pretilt angle was discussed.

文章用均苯四酸二酐、4，4'-二胺基二苯甲烷和具有较大支链的4-（4-苯甲酰基）环己基－3，5-二胺基苯甲酸酯等单体制备聚酰亚胺，首次研究了单体加料顺序对液晶预倾角的影响，同时也研究了二胺配比对液晶预倾角的影响问题，并探讨了预倾角的热稳定性等问题。

This is a new way for comprehensive utilization of waste fat and oil. The dropping points of lithium grease and lithium-calcium complex grease can be improved through adding the complex additives. Oxalic acid and sebacic acid are effective on lithium grease' and lithium-calcium complex grease' respe...

采用加入复合剂提高锂基润滑脂和锂-钙基润滑脂的滴点，加入草酸复合剂对所制备的锂基润滑脂的滴点的提高最为有效，加入癸二酸复合剂对锂-钙基润滑脂的滴点提高效果最好。

In attempt to obtain a further insight into the contribution of charged residues to other allosteri c properties , in this study we designed and synthesized a site directed mutan t , b82 Lys-Asn , for examing influencs the tetrameric stability and enthalpit ic change in O2 binding of human adult hemoglobin.

本研究焦点放在血红蛋白中央空腔中，带有正电残基的其中一个位置，b82 Lysyl ，来研究其正电离子效应与人类血红蛋白氧合反应热及四合体安定性的相关。针对这个目标，我们利用电脑做胺基酸序列排列比对和分子结构的模拟，选择以Asparaginyl残基取代Lysyl残基。

Hydroesterification of tert-butyl alcohol with ethanol catalyzed by transition metal triphenylphosphine complexes were investigated in room temperature ionic liquids as reaction medium at 100-140℃ and 3-6MPa of CO.

首次在超强酸氯铝酸离子液体中实现了饱和烷烃的羰化反应。发现2，2，4-三甲基戊烷可直接与CO反应，产物叔丁基异丁基酮，叔丁基异丁烯基酮和3，3，5-三甲基环己酮。

Base played a crucial role in this reaction: in the Pd2/L1 catalyzed α-arylation of ethyl malonate, K3PO4 is the base of choice; in the α-arylation of ethyl acetoacetate, K2CO3 is the most effective base.

在这类催化反应中，碱的选择具有重要的影响：以K3PO4为碱， Pd2/L1催化体系在丙二酸二乙酯的α-芳基化中，富电子溴代芳烃显示较好的活性； Pd2/L1催化的乙酰乙酸乙酯α-芳基化时，以 K2CO3为碱，催化体系显示较好的活性，这个催化体系可控制反应得到α-芳基乙酰乙酸乙酯，而不是脱乙酰基的产物。

Base played a crucial role in this reaction: in the Pd2/L1 catalyzed α-arylation of ethy malonate, K3PO4 is the base of choice; in the α-arylation of ethyl acetoacetate, K2CO3 is the most effectiv base.

在这类催化反应中，碱的选择具有重要的影响：以K3PO4为碱，Pd2/L1催化体系在丙二酸二乙酯的α-芳基化中，富电子溴代芳烃显示较好的活性；Pd2/L1催化的乙酰乙酸乙酯α-芳基化时，以K2CO3为碱，催化体系显示较好的活性，这个催化体系可控制反应得到α-芳基乙酰乙酸乙酯，而不是脱乙酰基的产物。

Electron transfer reaction between the radical cations of purine nucleotides and some aromatic amino acids was studied by use of pulse radiolytic techniques. Time-resolved spectroscopic evidence revealed that the one-electron-oxidized radicals of dAMP and dGMP can be efficiently repaired by tyrosine and tryptophan.

鉴于在DNA光敏损伤过程中主要生成嘌呤碱基阳离子自由基，利用脉冲辐解技术研究了嘌呤碱基阳离子自由基与部分芳香氨基酸的相互作用，获得了酪氨酸和色氨酸对单电子氧化的dAMP和dGMP经快速电子转移修复的瞬态吸收光谱证据。

With the nitrobenzene、 m-chloronitrobenzene、 m-nirtobenzenesulfone sodium salt for bottom thing, Grinard agent is a nucleophilic reagent reaction for under the different term proceeds a series reaction.

以苄基氯化镁为亲核试剂，以硝基苯、间硝基氯苯、间硝基苯磺酸钠为底物进行亲核取代反应，探讨与芳环相连的吸电子基团的数目及吸电子性，对亲核取代反应的影响。

MS results revealed that 3- propionaldehyde was transferred into 3- propanol, 3- propanoic acid, 3 ethanol, 3- timonacic.

质谱鉴定其转化产物有甲硫基丙醇、甲硫基丙酸、甲硫基乙醇、甲硫基丙烯。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。