分子

By comparing the amino acids sequences of SCRs of different regulators of complement activation and homologous structure units of DAF in different species, the conservative and nonconservative amino acids in DAF were determined. The possible activity sites were analysed and mutation amino acids sites to construct the mutant library were defined.3. Constructing and evaluating of yeast display mutant library on DAF scaffold.

SCRs多重序列比较及DAF突变位点的选择通过对补体调控蛋白家族成员、不同种属DAF分子的同源结构单位SCR的氨基酸序列进行多重序列比较，确定了DAF分子中的保守性氨基酸和非保守性氨基酸，并根据已有的实验结果，对DAF分子可能活性位点进行了分析，确定了构建酵母细胞表面呈现库的突变氨基酸位点。

The latter disappears due to the dissociation of the cyclic recognition sites in flexible PEG-1O00, and the pattern changes to noncyclic recognition.

另一种模式是环型识别；聚乙二醇主体分子和有机化合物客体分子以一种环状的集团结构方式发生选择性分子间作用力。

Aiming at two key issues in the molecular design of high-spin moleculesand organic ferromagnets, i.e., the ferromagnetic coupling strength in localradical fragments and the changeover of coupling capabilities offerromagnetic coupling units in building high-spin molecules, we made anextensive and deep investigation on numerous important conjugated radicalsystems within the semiempirical and nonempirical VB model, respectively.

针对高自旋分子和有机铁磁体的分子设计中的两个重要问题，即自由基片断的铁磁偶合强度及铁磁偶合单元在&建造&高自旋分子时其偶合能力的变化，分别用半经验的和非经验的VB模型，以一些重要的共轭自由基体系为对象进行了广泛而深入的研究。

A new method for ab initio energy partition is being developed in order to gain new insight into the nature of electron delocalization, and it is able to provide any molecule with a fragment MO basis set in which the π and σ systems have been separated out no matter whether molecule is planar or nonplanar as well as whether the π system is conjugated or cumulated.

我们的方法可以为任何一个共轭分子(无论是平面的还是非平面的，是含共轭双键的还是含累积双键的)，提供一个π与σ体系彻底分离的片断分子轨道基组。这个轨道基组不仅满足分子特殊的对称性，而且还具有确切的电子占据数。

Based on the analyses of the obtained sequences and the sequences from other three representative species of Oscillatoriaceae, and two species of Microcystis , the evolutionary affiliation among the genera of Oscillatoriaceae was discussed.

并通过计算机联网从国际分子生物学数据弹库中获取颤藻科其它种的rDNA基因间隔区序列，通过比较分析，从分子水平对颤藻科Oscilatoriaceae属间的某些分类学问题进行了讨论，并根据序列中核苷酸差异值探讨了颤藻科属间界定的分子标准。

The total energies,ionization potentials and electron affinities of two geometric structures of O_4 are given.Compared with the calculated results of oxy...

与氧原子、普通氧分子O2和臭氧分子O3的计算结果比较，显示O4分子可以以正方形结构或正四面体结构形式存在，其中正方形结构更有可能是O4分子的真实空间结构。

Ancient biomolecules obtained and characterized from in situ Quaternary fossils or sedimentary matrix have provided Quaternary scientists with quantitative and high resolution data that contain rich and some times unique paleobiological, paleogenetic, and paleoenvironmental information.

作者预见对第四纪地层中的原位和分散保存的古代生物分子的研究将在广度上以多分子综合研究而深度上与单体分子同位素技术相结合，为第四纪科学家们提供大量解决地质学和演化生物学问题的高精度数据。

Since Watson and Crick have brought forward the model of DNA helix structure and explain about it's reproduce mechanism in molecule level, research work concerning DNA has been continuously lucubrated. However, whether translating inheritance information and rebuilding DNA molecule via menstruating DNA sequence, or to date the most compelling gene project, chromosome protract et. al, there all need a sort of molecule scissors cleaving DNA, DNA cleavage reagent. At present, tool enzyme of cleaving DNA is mostly DNA restriction enzymes founded in 70 years, which only cleave DNA at specific 4-8 base pair sequences that are usually palindromic, so this restricts the at very fast speed developing of gene technology at certain extent.

自从Watson和Crick提出DNA的双螺旋结构并对其复制机制在分子水平上进行解释后，使得对DNA的研究不断深入，但无论是通过测定DNA的序列来破译遗传信息、改造DNA分子，还是目前最令人关注的基因工程、染色体绘制等，都需要一种断裂DNA分子的&剪刀&——DNA断裂试剂，目前断裂DNA的工具酶主要是上个世纪70年代发现的DNA限制性内切酶，但所知的Ⅱ型限制性内切酶的DNA序列识别长度较短（约为4～8个碱基对），而且一般要求回文结构，这就给飞速发展的基因工程技术带来一定的限制。

It is very suitable for pentaerythritol derivatives to be applied to synthesize new glycocluster and glycodendrimer because of their special structural characters.

由于季戊四醇衍生物本身所具备的结构特点，这类分子非常适合于合成新型的糖簇分子和糖树枝状分子。

In this study, effect of initiator, pH, temperature and time on products showed that different relative molecular weight were obtained by means of changing these factors. The standard method was used to study the connection between the scale inhibition and the relative molecular weight of PESA.

通过对PESA聚合过程的研究，找到了影响PESA相对分子质量的关键因素，得出了通过调节引发剂的添加量、改变反应温度等控制PESA相对分子质量及其分布的方法，制备了相对分子质量从400～1200的PESA。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。