选择反应

In order to study the aldol condensation of 2.15-hexadecanedione on the surface of aluminium, the intermolecular condensation mechanism of acetone occurring on aluminum was simulated by using semi-empirical AM1 method embodied in MOPAC 6.0 program package. The optimized structures and geometry parameters of 5 transition complexes and 4 intermediates were given.First, 2 molecules of acetone coordinated with aluminum by electrostatic attraction.One atom of hydrogen of acetone migrated to aluminum because of t...

为了研究2，15－十六烷二酮在氧化铝表面的环合机理，选择小分子丙酮为模型化合物，用量子化学半经验AM1方法研究双分子丙酮在氧化铝表面的醛醇缩合机理，给出了反应过程中的5个过渡态和4个中间体的结构和几何参数，该催化反应可以认为是氧化铝分子与两分子丙酮分子发生静电络合作用，然后借助氧原子的负电荷导致脱氢并实现缩合，根据中间体的能量变化，推测有较稳定的铝复合物生成。

For the aerobic oxidation of benzyl alcohol reaction,metallic palladium supported on the SiO_2-Al_2O_3 support was used as catalysts.

研究主要涉及以氧气为氧化剂的苯甲醇选择氧化反应和在惰性气氛中无氢受体存在的条件下的苯甲醇氧化脱氢反应两部分。

The possibility and extent of the goal reactions could be evaluated based on these calculations. The theoretical calculations also provided the basis for the choice of suitable catalysts and reaction conditions. The experimental results have demonstrated that the thermodynamic calculations are correct.

通过计算可判断所研究反应进行的可能性和程度，对催化剂和反应条件的选择提供了理论依据，实验结果也证明了热力学计算的正确性。

Chiral ligands mentioned above and their complexes with acetate copper were used as enantio-selective catalysts in asymmetric cyclopropanation reactions of diazoacetate and 1,1-diphenyl ethylene. Investigations indicate that all of them reveal certain optical-selective capability, but chiral C2-symmetric 2,6-bispyridine ligands show better catalytic capability than chiral asymmetric schifF-base ligands.

选择了2个手性2，6-吡啶双噁唑啉配体和6个手性不对称席夫碱配体与醋酸铜形成的配合物作为催化剂，对重氮乙酸乙酯与1，1-二苯乙烯不对称环加成进行催化反应，发现这8个催化剂对1，1-二苯乙烯的不对称环丙烷化反应都表现出了一定的光学活性诱导能力，手性2，6-吡啶双噁唑啉-铜类具有比手性Schiff碱-铜类更好的催化性能。

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。

Part Ⅰ The Research of Chiral Phosphorus Catalysts in the Enantioselective Borane Reduction of Prochiral Ketones ABSTRACT In this paper, the preparation of varied types of chiral phosphorus ligands and their applications as catalysts in the asymmetric borane reduction of prochiral ketones were investigated.

第一部分对映选择的潜手性酮的硼烷还原反应中手性磷催化剂的研究本文研究了多种不同类型的手性磷配体催化剂的合成及其在酮的不对称硼烷还原反应中的应用。

The monoclonal antibody was produced by the method of inoculating BALB/c mice intraperitoneally with the hybridoma cells, and purified with protein A-Sepharose 4B affinity chromatography.3 Establishing of ELISA protocol to detect hBLySTwo kind of different ELISA protocols were tried to study the experiment condition of detecting hBLyS level. Streptavidin was used to indirect coating in protocal 1, but biotin-avidin system was used to enlarge the final reaction signal in protocal 2. The optimal reaction condition was chosen by the experiments. The sensitivity of protocal 1 was poor, but the linear relation of protocal 2 standard curve was excellent when the concentration of hBLyS was between 3.2~400 ng/mL. So a protocal was established which sensitivity can reach to nanogram.

建立检测hBLyS蛋白含量的ELISA方法选用2种ELISA方案对hBLyS蛋白含量的测定方法进行研究，方案一用链霉亲和素做间接包被，方案二用生物素-亲和素系统做终反应放大；优化选择2种检测方法的反应条件；方法一的敏感度较低：方法二在hBLyS蛋白浓度为3.2～400 ng/mL范围内，标准曲线的线性关系良好；从而建立了一种可检测hBLyS蛋白浓度为ng级水平的ELISA方法。

The analysis which is only based on price-deciding is not very complex, but to study the dynamics response of non-pricing competition, the matter is not that simple. First of all we must choose what is the most effective means of competition, or a combination of several methods. Secondly we must take into account the opponent how to make a strategic response.

仅仅对于定价的分析并不很复杂，可是要研究非价格竞争的动态反应，事情就不那么简单，首先我们必须得考虑选择何种最有效的竞争方式，或者是几种方式的组合；其次我们必须得考虑到对手会作出何种战略反应，最后我们还得决定资源投入的最优数量。

In part one, a new method for the synthesis of nitriles by phase transfer catalytic reaction is introduced.

选择了一些在相应的反应温度下为液体状态的脂肪族和活泼的芳香族卤代物或酯为氰化反应底物，进行了无溶剂条件下的腈化物的合成。

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％。