分子

Though the result was not so good, a general understanding of the problems lying in the manufacture process of the device was gotten.We found the symmetry was destroyed or decreased in the crystal structure of symmetrical star-shaped molecules, such as tetra(4-cyanophenoxymethyl-methane, tetra(N-pyrrolemethyl)methane, and a center of charility was self-formed.

本文发现，原本高度对称的星状分子，在晶体结构中，分子对称性破坏或降低，表现为手性分子；以四(4-氰基苯氧基甲基)甲烷为例，从分子间氢键作用的角度，解释了该现象形成的原因。

We found the symmetry was destroyed or decreased in the crystal structure of symmetrical star-shaped molecules, such as tetra (4-cyanophenoxy methyl -methane, tetra (N-pyrrolemethyl) methane, and a center of charility was self-formed. The phenomena was discussed by analyzing the intermolecular hydrogen-bonding interactions of tetra (4-cyanophenoxy methyl -methane.

本文发现，原本高度对称的星状分子，在晶体结构中，分子对称性破坏或降低，表现为手性分子；以四（4-氰基苯氧基甲基）甲烷为例，从分子间氢键作用的角度，解释了该现象形成的原因。

Then, the equation of quantitative structure-activity relationship was effectively established with four descriptors like the molecular volume V(subscript m, order zero chi index, sum of the product of solvent-accessible surface area multiplied by partial charge for all positively charged atoms (Jurs-PPSA-3), and molecular surface area.

QSAR方程含分子体积V、分子分支度指数CHI-0、分子中带正电荷原子的溶剂可积面积与其所带电荷之积的加和值Jurs-PPSA-3以及分子表面积S4个结构描述符。

It was found that thionine, cobalt porphrin, rigid molecular wire, and iodide can all act as "molecular glue" for gold nanoparticles.

我们发现硫瑾染料分子、钴卟啉染料分子、刚性分子导线、碘离子都可以作为连接金纳米粒子的"分子胶水"。

Thus, a topological rubber glove is ofsuch a structure that is topological achiral and has topological point group 〓 in 〓space.

我们的结果表明：具有拓扑点群〓的分子是拓扑手性的；具有拓扑点群〓的分子是拓扑非手性的；如果一个分子在三维空间具有拓扑点群〓，那么这个分子具有拓扑橡胶手套的性质。

The C30 carbyne trefoil knot studied is intertwined by the sp hybridized15 chain, which is topologically chiral and belongs to D 3 point-group of symmetry.

三叶结分子是最简单的非平凡纽结分子， C30卡宾三叶结分子是由一条闭合的15 sp杂化碳链组成的，是具有 D 3对称性的拓扑手性分子。

The trefoil is known as the simplest nontrivial molecular knot. The C30 carbyne trefoil knot studied is intertwined by the sp hybridized15 chain, which is topologically chiral and belongs to D3 point-group of symmetry.

三叶结分子是最简单的非平凡纽结分子，C30卡宾三叶结分子是由一条闭合的l5 sp杂化碳链组成的，是具有D3对称性的拓扑手性分子。

The minimal energy conformations of host-guest complexes were obtained with Tripos force field. Molecular dynamics simulations were carried out to investigate chiral molecular recognition and the distribution of hydrogen bonds. The energies of recognition system were calculated with MM+ force field as well.

首次将分子力学方法引入卟啉的手性分子识别领域的研究；用Tripos力场研究了主客体配合物最低能量构象，比较了同一主体与互为对映异构体的两个氨基酸甲酯形成的配合物的能量差异；用分子动力学模拟方法研究了手性分子识别行为及体系的氢键分布；用MM+力场研究了识别体系的能量。

After two-cluster testing,branch length testing and relative rate testing ,two sequences(Melantitta nigra and Aythya americana) of 15 Cty b sequences were deleted because thek evolutionary rate were heterogeneous. The divergence between Anseriformes and Galliformes was chosen as an anchor point. Nucleotide sequence and amino acid sequence of 13 sequences data set was used to calibrated Anatidae molecular clocks. The results indicated that amino acid sequence is better than nucleotide sequence when divergence time is calculated with two kinds of sequences. The reliable divergence time of Anatidae were estimated with """"1+2TiTv"""" model.

经过二簇检验、分枝长度检验和相对速率检验，删除2条速率不恒定的序列后，用剩余的13条序列，以鸡形目与雁形目的分歧时间(89.8MYA)为锚定点，用顺序标定法标定鸭科鸟类分子钟的分析结果表明，用&1+2TiTv&分析得到的鸭科鸟类的分歧时间比较可靠；氨基酸序列用泊松校正模型和Γ模型估计的分类单元间的分歧时间则比较一致，表明氨基酸序列更适合用于鸭科鸟类分子钟的研究；用同一基因标定分子钟时，较长序列得到的结果标准误比较小；与核苷酸序列相比，氨基酸序列更适于用作分子钟的标定。

As mentioned above, this dissertation can be divided into two parts. One is devoted to study the high resolution ro-vibrational spectra of some asymmetry top molecules, such as D〓O and DOCl. Another is about studying anharmonic force field and vibrational intensities of some symmetry top molecules by quantum chemistry method, such as SiHCl〓 and AsH〓.

因此本论文的工作以此为脉络分为两个部分，第一部分以D〓O和DOCl分子为体系，研究非对称陀螺分子的高分辨振转光谱；第二部分以对称陀螺SiHCl〓和AsH〓分子为体系，用量子化学计算的方法研究了小分子的非谐性力场和振动光谱强度。

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。