四体的

Cephalotaxine ester of 2-oxo-6-methylheptanoic acid was treated with lithium diisopropylamide and Me O-(1-methoxyisopropyl)glycolate to give a mixture of homoisoharringtonine and its stereoisomers with 56% yield. The four stereoisomers separated by TLC showed identical mass spectra and almost superimposed IR but with different 1H NMR spectra. The configuration of the 2'-C and 3'-C of the four isomers were postulated based upon their 1H NMR spectra as compared with the 1H NMR spectra of isoharringtonine and its stereoisomers.

2-氧代-6-甲基庚酰基三尖杉碱(3)与0-(1-甲氧基异丙基)羟基乙酸甲酯(4)在强碱性试剂二异丙胺锂存在下，起亲核加成反应，反应中间体5在室温用酸性丙酮水解，得到一种新的三尖杉酯类生物碱一一高异三尖杉酯碱(6c)及其立体异构体(6a、6b、6d)的混合物，产率56%、通过制备薄层层析分得这四个立体异构体，它们的1H NMR和异三尖杉酯碱及其立体异构体的1H NMR类似，推定了它们的绝对构型。

The lifetime of M intermediate of BRE194Q was less than 1.0 s by photomicrography. The lifetime of M intermediates of BRI119T/T121S/A126T and BRI119T/T121S/A126T/E194Q were 3.0 s and 2.0 s, respectively.

显微视频录像技术记录的PVA膜中样品的M态寿命表明，野生型BR的M态寿命最短，单突变体的M态寿命小于1.0 s，三突变体的寿命为3.0 s，四突变体的寿命为2.0 s。

The lifetime of M intermediate of the three mutants in PVA films were recorded by employing photomicrography. In distilled water, the visible absorption maximum of BRI119T/T121S/A126T and BRI119T/T121S/A126T/E194Q mutants were blue shifted notably by 11 and 12 nm respectively and the BRE194Q's was weakly red shifted in comparison with WT-BR.

与野生型BR相比较，在水溶液中，单突变体的可见吸收光谱的最大吸收峰发生了轻微红移，三突变体和四突变体的最大吸收峰则分别发生了11.0和12.0 nm的明显蓝移。

The lifetime of M intermediate of BR(subscript E194Q) was less than 1.0 s by photomicrography. The lifetime of M intermediates of BR(subscript I119T/T121S/A126T) and BR(subscript I191T/T121S/A126T/E194Q) were 3.0s and 2.0s, respectively.

显微视频录像技术记录的PVA膜中样品的M态寿命表明，野生型BR的M态寿命最短，单突变体的M态寿命小于1.0s，三突变体的寿命为3.0s，四突变体的寿命为2.0s。

The lifetime of M intermediate of the three mutants in PVA films were recorded by employing photomicrography. In distilled water, the visible absorption maximum of BR(subscript I119T/T121S/A126T) and BR(subscript I119T/T121S/A126T/E194Q) mutants were blue shifted notably by 11 and 12 mm respectively and the BR(subscript E194Q)'s was weakly red shifted in comparison with WT-BR.

与野生型BR相比较，在水溶液中，单突变体的可见吸收光谱的最大吸收峰发生了轻微红移，三突变体和四突变体的最大吸收峰则分别发生了11.0和12.0nm的明显蓝移。

The excited-state intramolecular proton transfer tautomerism reaction of 6-methyl-4-hydroxy pyri-midine monomers and dimmers was investigated by the ab initio method with the self-consistent reaction field with Tomas's polarized continuum mode and CIS theories at HF level on the basis of 6-311+G* and 6-31G basis set. By studying the potential energy surface, it was found that the monomer's ground-state proton transfer process together with the excited-state proton transfer process is a molecular system of four energy level, but dimmers were not, which can be used to explain the fact that UV-visible absorption and fluorescence spectra of monomer and dimers all corresponded to quinoid.

采用 ab initio HF理论的组态相关CIS方法和连续溶剂模型PCM，分别在6-311+G*和6-31G水平上研究了6-甲基-4-羟基嘧啶单体及二聚体激发态质子转移的异构化反应；对其反应势能面的研究发现，单体基态和激发态的异构化反应一起可以形成四能级的分子电子体系，而二聚体的却不能，由此解释了单体和二聚体的紫外吸收光谱和荧光发射光谱均对应于酮式构型的原因。

Experimental mice were exposed to Trypanosome evansi after injection by different doses of antigenic reservoir. The results showed that 20 μg dose produced 83% and 67% protection to 2 sample variations after 4 immunizations. However, 3 immunizing doses could not give good protection. No protective effects were detected when experimental animals immunized by single VSG exposed to isotype from different rabbits.

用不同剂量抗原库免疫小鼠后进行攻虫，结果显示：经四次免疫后，20μg 剂量对随机抽取的两个变异体100 条虫体的保护率分别达到 83%和 67%；改变免疫方法，经三次免疫后的保护效果不理想；用单一 VSG 抗原免疫小鼠，接种来自不同兔体的同型虫体，不能起到相应保护作用。

Result showed that tetrasubstituted calix [4] arenes in lower rim were stronger complex abilities than bisubstituted calix [4] arene with transition metal, heavy metal and rare earth ions. But when introducing the aminephenolicalcohols in the 1, 3-bisubstituted calix [4] arenes, the complex abilities were improved.

结果表明：在Lower rim上四取代的杯[4]芳烃配体比1，3-二取代的杯[4]芳烃配体对过渡金属离子，重金属离子及稀土离子有更好的配位能力，但当1，3-二取代的取代基上引入醇胺链型配体时，对金属离子也有很好的配位能力。

How to process it affects the equivalent prediction of the entire conductor performance. According to the traditional composite theory, the following several predictions were carried: only consider the functions of the stainless steel conduit outside the cable body, the double insulation and the double shielding layer; the influence of the flexible cable body is neglect, so only consider the function of its internal helium tube; the material nature of the cable body is assumed the isotropism, which the elasticity modulus is 1-10 GPa (here taking 2 GPa); combining the homogenization theory with the composite damage theory.

在传统复合材料理论的基础上，对ITER超导电流传输线导体等效弹性模量进行理论预测：预测一，只考虑电缆体外的不锈钢导管、双绝缘和双屏蔽层；预测二，忽略柔性电缆体的影响，但考虑其内部氦管；预测三，假设电缆体呈各向同性，弹性模量取1～10 GPa；预测四，利用均匀化理论分析电缆体的等效弹性模量，复合材料损伤理论分析超导电缆与中心氦管之间、电缆复合体和不锈钢导管之间界面情况。

The characteristics of the resting nuclei and the prophase chromosomes of all the tetraploids and hexaploids were quite similar to each other.

所有四倍体和六倍体的体细胞间期核特征和前期染色体形态特征基本相似。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。