选择性的

To probe into either the attractiveness to or avoidance from phylloxera of grape rootstocks and cultivars with different tolerance, as well as into the volatile components from their roots, the method of invitro root segment culture was used to investigate the selectivity of Phylloxera viticola Fitch to the roots of grape rootstocks '5BB' and '140Ru' and cultivar 'Kyoho'.

为了探讨不同抗性水平砧木及品种对根瘤蚜吸引及驱避效应以及鉴定挥发性物质组分，采用离体根段培养法测定葡萄根瘤蚜Phylloxera viticola Fitch对砧木5BB，140 Ru及栽培品种巨峰的选择性，发现根瘤蚜对栽培品种巨峰的根段具有很强的选择性，至接种后3d，67.13%的根瘤蚜优先选择巨峰；而对5BB和140 Ru的选择性却很差，分别有15.29%和17.58%的根瘤蚜选择5BB及140 Ru。

The third part elaborates the strategy of selectivity attention and the factors which affect it, then combining with the design of web-based course "The Design of Active Sever Page" which was designed by the writer, elaborates how to apply the strategy of selectivity attention in the the web-based course: 1 design clear navigator; 2 ascertain the target of instruction; 3 take problem as the direction to cause the student's attention;4 the preceding analysises: the analysis of the need of study, the analysis of learner and the analysise of study content; 5 combining muultiual sensorial passages to present the stimulability to course the attention of the learner; 6 enhance the characteristic of the main body to cause the student's attention;7 emphasize the student's position as main body.

第三部分详细介绍选择性注意策略及影响选择性注意策略的因素，之后结合笔者设计的《 ASP 动态网页设计》网络课程具体阐述网络课程中选择性注意策略的应用：1设计清晰的导航；2确定可观察可测量的教学目标；3以问题为导向引起学生的注意；4前端分析：学习需求分析、学习者分析和学习内容分析；5多通道结合呈现刺激，引起学习者的注意；6强化主体的特征引起学生的注意；7强调学生的主体地位。

The E-TOF will also be feasible and practical to assist chemists in screening the optimal reaction condition or evaluating the overall efficiency of different catalytic systems for a specific asymmetric reaction.4.For the first time,we explored chiralγ-hydroxy-α,β-acetylenic esters,which were prepared via asymmetric alkynylation,as key intermediates to the synthesis of chiralγ-butyrolactones. This convergent and enantioselective approach to chiralγ-butyrolactones is practical and easily handled with protecting group free.

这一概念包括反应产率、对映选择性、配体用量以及反应时间四个重要反应参数，不仅适用同一反应不同催化体系的横向综合性评价，而且适用于某一特定反应催化体系的优化过程，有助于研究人员选择最佳的反应条件。4、我们发展了以手性γ-羟基-α，β-炔酸酯为关键中间体完成了手性γ-丁内酯类天然产物的对映立体选择性全合成，该关键中间体能够以我们的催化体系方便的对映选择性合成，之后的官能团转换方法成熟，易于操作，无需进行繁琐的官能团保护和脱保护过程，绿色经济。

Moreover,the selective oxidation of primary and secondary alcohols to corresponding carbonyl compounds with the multinuclear copper complexes Cul-Cu4 as catalysts have been conducted using TBHP and O_2/TEMPO,respectively.Among them,the copper complex Cu3 showed the best performance.On the performances of the two classes of oxidants,benzylic and heterocyclic alcohols could be effectively oxidized to carbonyl compounds.Specifically,the secondary alcohols could be effectively oxidized to ketones with excellent selectivity up to 100%in the presence of TBHP and the allylic alcohols could be effectively oxidized to aldehydes in the presence of O_2/TEMPO system.

实验结果还表明，在TBHP或O_2/TEMPO存在下，各配合物催化剂均能使各种取代芳香伯/仲醇以及杂环醇等以不同程度的转化率和选择性转化成相应的醛或酮，其中，配合物Cu3在O_2/TEMPO存在下可使苯甲醇和烯丙醇等以较高转化率和近100%的选择性转化成相应的醛，而对其它芳香醇和脂肪伯/仲醇等的催化性能则较差；在TBHP存在下，配合物Cu3则可使1-苯乙醇和其它仲醇以较高转化率和近100%的选择性转化为相应的酮，但对各类其它伯醇选择氧化的性能相对较差。

The temperature and the addition of surfactant can accelerate conversion and selectivity of reaction. Under the conditions of 200℃、0.38MPa、0.06 mol/L、t=4h,the conversion of hexene is 86.32%.Selectivity of 2-hexene and 3-hexene is 30.46% and 57.86%.

结果表明，当表面活性剂的加入以及反应温度的升高，能明显提高反应的转化率和选择性，在200℃、0.38MPa、0.032 mol/L的反应条件下，反应4小时底物转化率为86.32%，3-己烯的选择性为57.86%，2-己烯的选择性为30.46%。

It was found that manganese porphyrins linked with stable nitroxyl radials could oxidize sulfides using NaOCl as the oxidant to give the corresponding sulfoxides in good to excellent yields (80-97%) with high chemoselectivity and diasteroselectivity (dr≥7:1 for glycosyl sulfoxides).

发现连有稳定氮氧自由基的卟啉锰络合物对NaOCl选择性氧化各种硫醚底物有较好的催化效果，获得了高的产率(80％～97％)、化学选择性和非对映选择性(糖基亚砜非对映异构体的比例大于7：1)。

New reactions found in this program include: photoinduced regioselective free radical addition to aromatic imines;photoinduced Dielse-Alder reactions of aromatic imines for synthesis of tetrahydroquinoline derivatives;Photoinduced radical cation mediated selective ring opening reaction of epoxides;Formation of novel macrocyclic crown ethers by photoinduced reaction of diazonaphthaquinones;photoinduced selective desilylation of silyl ethers.

用这种方法成功的发现了下列在有机合成中有意义的新反应：(1)光诱导产生的自由基正离子诱导的自由基对芳香亚胺的区域选择性加成反应；(2)用光诱导的芳香亚胺的Diels-Alder反应合成四氢喹啉衍生物；(3)经光诱导产生的自由基正离子基诱导的环氧化物选择性开环反应；（4）重氮萘酮在环醚中经光诱导反应形成新奇的大环冠醚；（5）硅醚的光诱导选择性脱硅基反应。

The synergistic effect of Cu and Mn is listed as follows:(1) On improving the structure of rust layer, addition of Cu and Mn can reduce cracks and pores in rust layer;(2) On altering the composition of rust, it can increase the amount of Fe3O4 and γ-FeOOH, while decrease that of β-FeOOH;(3) On the chemical state of alloying elements and selectivity of rust layer, it mainly convert the anion selectivity to canoed selectivity;(4) On the electrochemical aspect, it can decrease the anode current density and increase the corrosion potential of steel.

Cu、Mn的协同作用主要体现在以下几个方面：在改善锈层结构方面，主要是减少锈层中的裂纹与孔洞，提高锈层与基体的结合强度；在改变锈层组成方面，增加Fe3O4和γ-FeOOH的含量，降低β-FeOOH的含量；在元素化学状态与离子选择性方面，促使锈层由阴离子选择性转变为阳离子选择性，抑制Cl-的渗透；在电化学方面，大幅度降低阳极电流密度，提高钢基体的自腐蚀电位。

In order to improve size selection for shrimps of multi-codends beam trawls fishing in offshore of the East China Sea,experiments of several sea trials for size selectivity of codends with different mesh configuration, including diamond mesh, square mesh and turned through 90° mesh,have been carried out and catch data were collected by comparative fishing method.

选择性模型对哈氏仿对虾和葛氏长臂虾渔获数据的拟合结果显示，选择性模型具有较好的拟合性，但存在航次间差异；不同网目结构网囊的选择性曲线模型都可简化为Logistic曲线；对于哈氏仿对虾，相比菱形网目网囊，方形网目和转向网目网囊的L50较大，而SR较小(菱形和方形网目之间差异显著，菱形和转向网目之间差异不显著)；对于葛氏长臂虾，方形网目和转向网目网囊的L50较大(菱形和方形网目之间差异显著，菱形和转向网目之间差异不显著)。

The NH〓/CO〓=2in accordance with the constitutes of ammonium carbamate can not be separated by ordinary methods, The separation way which used the different absorption rates of high gas velocity between ammonia and carbon dioxide in aqueous solution has been made up in this study.

在实验室高速喷射鼓泡反应器的条件下，研究了M〓/M〓=2的混合气体在水溶液中的选择性吸收过程，获得了良好的选择性效果：连续吸收的选择性因子S〓在2.06～8.23之间，S〓在2.86～10.83之间。

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。