选择性的

The mechanisms underlying these biases of subcortical neurons are still under investigation.

视皮层内较强的方位、方向选择性主要是由视皮层内部机制形成的，而皮层下神经元也具有明显的方位、方向敏感性，并对视皮层神经元的方位、方向选择性有初步的贡献，然而这种皮层下方位、方向敏感性的形成机制仍在进一步的探索中。

This discourse starts with the WTO safeguard clauses , analyses the safeguards cases in the international trade, studies the source, reality, validity of the selective and unselective implementations and states the view of its development.

本文从分析WTO保障措施的具体条款入手，结合国际贸易中保障措施的实际案例，深入研究了WTO保障措施实施方式的选择性和非选择性，在其存在的根源、现实性、合法性及这两种实施方式的今后的发展方向等方面提出了见解。

From the results of IR and XPS spectrocopy. The cationic sol components H〓SiO〓 and 〓 of the solution trend to adsorp on the surface of electronegative aegirine because of electrostatic acctraction each other, and interrupted the collector's reaction with Fe〓 on the surface. Hence the flotation of aegirine was decreased, on the other hand, there is electrostatic repulsion between the surface of hematite and the cationic sol H〓SiO〓.〓, Which has advantage to dispersion of hematite particles, therefore, the hematite flotation is achieved sucessfully with anionic collector.

根据红外光谱和XPS测试结果可知，在弱酸性介质中，活性硅酸胶体抑制剂中荷正电的胶团H〓SiO〓及〓由于电性吸引而选择性地覆盖在荷负电的钠辉石表面，从而阻碍了阴离子捕收剂与表面Fe〓的配位作用，导致钠辉石的浮游被抑制；而赤铁矿表面由于荷正电，与矿浆中的H〓SiO〓、〓等硅酸胶团存在着电性排斥作用，有利于赤铁矿颗粒的稳定分散，所以赤铁矿能够被脂肪酸捕收剂吸附而选择性上浮。

Through screening lipases, lipase Novozym 435 and lipase Alcaligenes sp were found to show higher activity and better enantioselectivity for the resolution of 2-(2-chloro- 1-hydroxyethyl)thiophene. The optimal reaction conditions were finally achieved by further investigating the effects of solvents, temperature, rotation speed and enzyme concentrations.

通过对不同来源酶的筛选，找到了Novozym 435和Alcaligenes sp两种选择性较好的酶，它们均对该反应具有较高的选择性和较快的反应速度，在此基础上进一步通过对溶剂、温度、摇床转速以及酶用量的筛选，确定了能够有效拆分2-氯-1-(2-噻吩)-乙醇的较佳反应条件。

In the forth part of the dissertation, based on the mechanism of classical Strecker reaction,we developeda new method for the asymmetric synthesis of the α,α-disubstituted amino acid, and applied it to theasymmetric synthesis of-αM4CPG, compound 11a and 11b.

在本论文的第四部分，我们从深入分析经典的Strecker反应入手，发展了一条新的以酮为原料出发的立体选择性地合成α，α-双取代的光学纯的氨基酸的方法，并且利用该方法立体选择性地合成了化合物-αM4CPG，11a和11b。

The results show that among the acetoacetonate complexes,Co_3 has the best catalytic activity.The optimum reaction conditions were as follows:0.764 mmol of Co_3,mole fraction of ethanal 10%based on the substrate,room temperature,oxygen pressure 2 MPa,reaction time 11h and solvent acetonitrile.Under these conditions,13.3%p-chlorobenzaldehyde was obtained with 15.3%conversion and 87.2%selectivity.The oxidation can also be carried out without solvent with 8.1%conversion,89.1%selectivity and 7.2%yield respectively.

在金属配合物中Co_3的催化性能最好，在其用量为0.764 mmol、乙醛用量为反应物物质的量的10%、氧气压力为2MPa时，以乙腈为反应介质，室温下反应11h，反应的转化率和选择性可达15.3%，87.2%，对氯苯甲醛收率可达13.3%；反应也可在无溶剂时进行，此时反应的转化率、选择性及醛的收率分别为：8.1%，89.1%，7.2%。

Both catalytic activity and selectivity of Ru(PPh_3)_3Cl_2 were improved in ionic liquid BMImPF_6/DME medium.The conversion of hexene and selectivity ofβ-adduct for the hydrosilylation reaction of 1-hexene with triethoxysilane catalyzed by Ru(PPh_3)_3Cl_2 in ionic liquid BMImPF_6DME (V/V=1/4) medium at 90℃were 100% and 89.0%,respectively.

实验结果表明，在乙二醇二甲醚/离子液体1-丁基-3-甲基咪唑六氟磷酸盐(BMImBF_6)(V/V =1/4)介质中，于90℃下，己烯与三乙氧基硅烷反应的转化率为100%，β加成物的选择性可达89.0%，而用Rh(PPh_3)_3Cl作为反应的催化剂，在纯离子液体BMImPF_6中，就可以高效催化烯烃与三乙氧基氢硅烷的加成反应，过渡金属Rh(PPh_3)_3Cl，Ru(PPh_3)_3Cl_2催化剂/离子液体BMImPF_6催化体系，不仅解决了产物与催化剂分离困难这一难题，同时，离子液体BMImPF_6的存在提高了过渡金属Rh(PPh_3)_3Cl，Ru(PPh_3)_3Cl_2催化硅氢加成反应的活性，特别是β加成物的选择性。

A composition that can be used as catalyst is disclosed, which comprises or is produced by combining, a titanium compound; either a complexing agent, a combination of a complexing agent, hypophosphorous acid or a salt thereof, and optionally a solvent, a zirconium compound, or both, combinations thereof; a phosphorus compound; and, optionally, a solvent.

公开了一种可用作催化剂的组合物，该组合物包括钛化合物；络合剂，或络合剂、次磷酸或其盐和选择性使用的溶剂、锆化合物或二者的组合，或它们的组合；磷化合物和选择性使用的一种溶剂；或是用它们的组合制成的催化剂。

This paper reports the experimental equipment and technology parameter for the synthesis of diisopropylbenzene and triisopropylbenzene by catalytic alkylation between benzene and propene, the conversion of benzene is more than 98%,the selectivity of diisopropylbenzene and triisopropylbenzene is more than 40% and 36% respectively.

报道了苯与丙烯催化烷基化合成二异丙苯和三异丙苯的实验装置与工艺条件，苯的转化率达98%以上，二异丙苯的选择性≥40%，三异丙苯的选择性≥36%，经分离后可获得纯度≥95%的二异丙苯和三异丙苯产品，所提供的合成工艺基本上无污染，在国内外具有先进的技术。

Study of the mesh selectivity of diamond and square mesh codend of two-stick swingnet;2. In order to assess the size selectivity for fishes of beam trawl fishing in offshore of the East China Sea,experiments of codends with different mesh configuration,including diamond mesh, square mesh and turned through 90° diamond mesh(T90) in 4 sea trials have been carried out and catch data were collected by comparative fishing method.

选择性分析结果显示，对于短吻舌鳎，横向使用的菱形网目网囊L50(50%选择体长)最大，而SR最小，菱形网目网囊L50最小，而SR最大；对于棘头梅童鱼和小黄鱼，菱形网目网囊的L50最小，SR最大，横向使用的菱形网目网囊L50最大，而方形网目网囊SR最小；除不同结构的网目扩张程度不同以外，鱼体体型结构的特殊性以及网囊结构也可能是导致选择性差异的主要原因。

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。