取代

The initial SAR studies indica ted:(1)the presence of alinker of methene at the N-1may be beneficial to anti-HIV activity,while longer chain could enhance toxicity;(2)substituted phenyl at the C-2could reduce toxicity;(3)6-substituted benzimidazoles generally showed higher anti-HIV activity than 5-substuted ones;(4)the presence of ahalogenated benzyl ring at the N-l would enhance anti-HIV potency and decrease cytotoxicity.

初步构效分析提示：(1)苯并咪唑环1位侧链间隔基为亚甲基时活性最好，侧链延长，毒性增大；(2)苯并咪唑2位侧链无间隔基毒性相对较低；(3)苯并咪唑6位取代活性高于5位取代；(4)苯并咪唑1位芳环用卤素取代，毒性明显降低。

Nitrations of both hydroxyl- and acetamino-substituted porphyrins were found to take place at the adjacent position of the substituent in the very aryl ring, whereas nitro group was guided into para positions of unsubstituted phenyl ring during the nitration of nitro-substituted porphyrin.

结果表明，羟基和乙酰氨基卟啉的硝化反应发生在与该取代基处于同一芳环的meta位，而硝基卟啉进行硝化时，硝基取代于其他未取代苯环的para位。

For the first time, this study conducted a series of field sampling in multiple locations over several years and demonstrated that the B and Q biotypes first invade areas with high frequency of transport through human movement of plant materials, and then rapidly spread into surrounding areas and displace indigenous genotypes, and in parallel with displacement significant changes in sex ratio occurred in the mixed populations. Crossing experiments demonstrated that in the B. tabaci species complex there are many genetic groups that are completely or nearly completely isolated in reproduction. Apart from behavioural mechanisms, difference in host plant suitability and insecticide susceptibility between whitefly biotypes may also play important roles in the displacement of indigenous whiteflies by alien whiteflies in Zhejiang.

本研究首次以一个地理区域内广泛系统的野外调查数据证实，B型和Q型烟粉虱首先通过花卉苗木调运入侵交通较为发达的地区，然后迅速向周边扩张并取代土著烟粉虱，同时入侵取代过程伴随着混合种群中性比的变化；杂交试验证明烟粉虱复合种内存在多个生殖上隔离或基本隔离的遗传群；B型烟粉虱在浙江省内迅速取代土著烟粉虱，除行为机制外，生物型之间寄主适应性和药剂敏感性等方面的差异也可能在此过程中起着重要作用。

The present paper take the purine synonym kui zuo lin as a parent nucleus, separately in its 4 and 7 introduction structure diverse substituted benzene amino and the flexible side chain, designed a series of 4- substitution anilino-- 6- methoxy - 7-(2- hydroxyl to substitute for third oxygen radical) kui zuo lin a kind of compound.

本论文以嘌呤类似物喹唑啉为母核，分别在其4位和7位引入结构多样的取代苯氨基和柔性侧链，设计了一系列4-取代苯胺基-6-甲氧基-7-(2-羟基取代丙氧基)喹唑啉类化合物。

The reactions of several phenols and 2, 2, 6, 6-tetramethyl-4-substituted piperidine oxoammonium salt have been studied. It was found that these oxoammonium salts are new facile reagents for phenolic coupling.

应用2，2，6，6-四甲基哌啶氧铵盐实现了酚类的氧化偶联反应：对位取代的酚类底物得到邻位-邻位偶联产物；2，6-二取代的酚类底物得到对位-对位偶联产物；2，4，6-三取代的阻碍酚类底物得到苄位氧化偶联产物。

On the one hand, one benzen ring of stilbene was substituted by one pyridine ring for the purpose of evaluating the bioactivities of azastilbenes. On the other hand, some stilbene derivatives with different substituents in different sites were designed for the study of SAR.

一，以吡啶环替代母核的一个苯环，考察分子中引入氮原子对活性的影响；二，改变母核上的取代基类型及取代位点，考察取代基在构效关系中的影响规律。

In this paper, 2,6-dimethyl-1,4-phenylene oxidel was modified by trimethyl chlorosilane and triphenyl chlorosilane, and a serfes of silyl-substituted PPO were synthesized.

讨论了聚2，6－二甲基－1，4－苯撑氧与三甲基氯硅烷和三苯基氯硅烷的反应，合成了一系列取代含量不同的三甲基硅取代PPO和三苯基硅取代PPO。

Substitutes on benzal benzene ring of BFP have different effects on ·OH scavenging activity in vitro. 2-Cl,3-Cl,2-CH3,4-CH3 and 3-OCH3 may enhance the activity. 3-CH3 may not change the activity.

BFP苄基苯环上2-Cl、3-Cl、2-CH3、4-CH3、3-OCH3取代，可增强体外清除·OH活性；3-CH3取代，体外清除·OH活性基本不变；2-OCH3、4-OCH3取代，体外清除·OH活性降低。

Substitutes on benzal benzene ring of BFP have different effects on ·OH scavenging activity in vitro. 2-Cl,3-Cl,2-CH3,4-CH3 and 3-OCH3 may enhance the activity. 3-CH3 may not change the activity. 2-OCH3 and 4-OCH3 may reduce the activity.

BFP苄基苯环上2-Cl、3-Cl、2-CH3、4-CH3、3-OCH3取代，可增强体外清除·OH活性；3-CH3取代，体外清除·OH活性基本不变；2-OCH3、4-OCH3取代，体外清除·OH活性降低。

To our surprise we achieved the ligand 9, 11 and 29 with coordinating atoms fixing at benzylic and benzene ring positions, whose structure is unique in the planar chiral cyclophane chemistry.

以钯催化的烯丙基取代反应对配体进行了考察，硫醚或硒醚取代基在苄位取代的配体表现出更高的反应活性和更高的对映选择性，配体9和11均给出最高为94％的ee值。

I'm strongly against the death penalty — it's an eye for an eye.

我不赞成死刑——这是以牙还牙的报复行为。

And to get you the support you need, we're enlisting all elements of our national power: our diplomacy and development, our economic might and our moral suasion, so that you and the rest of our military do not bear the burden of our security alone.

并给你们所须的支援，我们正徵召国家所有各种的力量：我们的外交及发展，我们的经济力量与道德劝说，所以你们与其他军人不须要孤独地负起国家安全的责任。