原子结构化学

With quantum chemical calculation, all the information about electronic and spatial structures of specific compounds can be obtained, including molecular orbital energy level, atomic charge density, polarizability, and electrostatic charge of molecules.

通过对化合物进行量子化学计算，可以获得有关分子的电子结构和立体结构信息，如分子轨道能级、原子的电荷密度、极化率以及分子的静电荷等。

In the work, three P-Mo-V heteropoly acids with different Vanadium number have been synthesized by acidification- etherization. Their component and structure have been confirmed by ICP-AES and TGA. They have been characterized by FT IR, XRD and UV. FT IR demonstrates their Keggin structure.

本文采用酸化—醚化法合成了三种不同钒原子数的P-Mo-V三元杂多酸，并用ICP-AES和TGA确定其化学组成和结构，用FT IR、XRD和UV等手段对其结构和性质进行了表征。

The results showing that α-Ti, atomic crystal with face-center structure became TiH2, ionic crystal with cubic-center structure, and there were two parallel process after electrolysis: chemical adsorption occured on the surface of material mainly, but dominant physical adsorption enhanced dislocation of crystal.

结果表明，电解后面心立方结构的原子晶体α-Ti转变成了体心立方结构的离子晶体TiH2；存在着两个不平衡的并行进程：化学吸附主要发生在材料表面，占优势的物理吸附强化了材料内部的晶体位错。

Chemical bonds and structural theory of organic chemistry 6 class hoursKnow the history of organic chemistry; Grasp the basic theory of organicchemistry, such as structural theory, chemical bonds, resonance theory, atomic andmolecular orbital theory, and valence bond theory; understand polar and non-polarcompounds, dipole moment and know how to express the structures of organiccompounds with different molecular formulas.

了解有机化学发展简史；掌握有机化学结构理论、化学键理论、共振理论、原子和分子轨道理论和杂化轨道理论；了解极性和非极性分子并掌握有机化合物结构的表示法。

As we all know, thermochemistry is the direct application of thermodynamic in the field of chemistry.

近年来，纳米结构材料引起人们极大的兴趣，对这些由有限个原子构成的小颗粒，再由这些小颗粒凝聚而成的纳米结构材料在热化学方面有什么新的特点，它与颗粒尺寸的关系和粗晶、多晶材料所遵循的规律是否一致，已成功描述粗晶和多晶热力学行为的经典热力学理论对纳米材料是否还适用，这些问题是纳米材料的深入研究和推广应用所必须解决的关键问题。

We explore the relation between structure and activity , structure and toxicity from electronic structure and three—dimensional conformation in order to provide theoretical foundations for predicting the activity and toxicity of these chemical compounds, researching into mechanism of action and choosing safener.

通过比较四种均三氮苯类除草剂的红外光谱特征吸收的实验值和计算值，并运用规范不变原子轨道法GIAO法在RHF/6-31G水平上计算出西玛津的δ~1H-NMR和δ~(13)C-NMR，与实验值的对比统计分析，结果表明：用RHF/6-31G优化的分子构型最佳，AM1法次之，考虑到优化时间和研究的需要，我们在研究均三氮苯类除草剂分子的结构与活性关系时，为了进行深入、精确的理论研究，采用从头算RHF/6-31G进行优化；而对于此类化合物的结构与毒性的关系研究时，更注重分子的量子化学参数的相对值而非绝对值，因而采用AM1的方法。

A theoretical study of the surface structure of silica-supported zirconium sulfate tetrahydrate with high catalytic activity for synthesis of 2-ethoxyethyl acetate has been investigated using the ASED-MO method (including atomic repellent energy).

采用量子化学ASED-MO(含原子对排斥的EHMO法)为基础的结构自动优化EHTOPT法研究了硅胶负载型硫酸锆表面相的结构特征。

The change for substitute group on chlorin ring of chlorophyll-a derivative and the effect on their visible spectra is discussed and summarized according to relation of electron effect and substituted position of different groups with conjugated region.

根据不同取代基的电子效应、取代位置与分子共轭区域的联系，提出二氮杂轮烯和四氮杂轮烯组成的非等原子芳香体系结构，总结了卟吩大环上的化学结构变化对其可见光谱的影响。

A satisfactory result was obtained,the correlation coefficient of the built model based on Leave-one-out Cross-validation were 0.990 0 and 0.986 7,respectively.This model is tested by 13C NMR chemical shift of three terpenoid compounds and the excellent result with correlation coefficients R =0.977 7 was obtained.

而C原子是组成有机化合物分子骨架的重要元素，其NMR谱包含了与该分子量子化学性质直接相关的信息[2]，因此，NMR谱被广泛应用于对有机化合物结构的鉴定[3-4]、动态过程和平衡及水溶液中蛋白质三维结构的研究(见2002年诺贝尔化学奖得主维特里希的成果)。

The results show that the diffraction patterns for WS2 single phase were observed; the pronounced quantum size effect exists in S-W-S nano clusters, and it enhances the hybridization of different electronic shell obits and formed a closed hollow spherical structure without any dangling bond. In the lubricating process, such a system can maintain its chemical stability and decrease energy dissipation.

分析结果表明：XRD图样显示为WS2相单相；在S-W-S纳米簇团中存在显著的量子尺寸效应，该效应强化了硫原子电子壳层间的轨道杂化，使纳米级的WS2润滑晶体形成了1个没有悬键的、化学性能稳定的中空球体，在润滑过程中，这种结构可使体系保持较强的化学稳定性，能耗降低。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。