量子化学

In this paper, we evaluated the performance of different quantum chemical methods for calculating ^13C chemical shifts of acetylsalicylic acid and its derivatives.

我们用量子化学的方法预测了乙酰水杨酸及其衍生物分子上碳原子的化学位移，并通过比较计算值和实验值得到不同理论计算方法的误差范围。

The supermolecule system building on the weak interactions between molecules has always been the focus on chemistry , bionomy , material science and informatics theoretically and experimentally . However , because the experiments fail to provide varied information in detail .

通过分子间弱相互作用构筑的超分子体系一直是化学，生命科学，材料科学，信息科学领域在理论和实验上的研究焦点，但对于分子间的相互作用体系，实验研究不能提供十分详细的各种信息，所以量子化学计算在补充其结构，能量，光谱等信息上有着重要的意义。

The chemisorption of CO on platinum clusters was treated by EHMO method.

本文用EHMO方法对CO在Pt原子簇上的化学吸附进行了量子化学计算。

As an example, we note that the relativistic correction to the hydrogen shielding in hydrogen iodide is about 15 ppm at the Hartree-Fock level, an effect that exceeds the normal shielding range of protons.

本文第二章首先引入了一种含有相对论效应的拟相对论的Hamiltonian，并运用到汞和碲等重核元素的核磁屏蔽常数和化学位移的量子化学从头算研究中。

With the development of quantum chemistry theory and computational technique, the excited state of molecules: a high-energy unsteady electronic state, has been investigated using accurate electronic structure theory methods.

随着量子化学理论方法和计算机技术的发展，量子理论模型已成为一种研究分子的高能、不稳定电子态－激发态的最有效手段。

Reaction trends of catalytic desulfurization of thiophene were determined based on the reaction energy needed, which was obtained with the AM1 calculation results of thiophene and possible carbonium ions on transition state.

采用半经验AM1计算方法，利用静态理论对噻吩在分子筛催化剂上的催化裂化脱硫机理进行了量子化学计算研究，通过对噻吩分子和可能产生的中间正碳离子的量子化学计算，得到各中间反应所需的能量，从而判断噻吩催化裂化脱硫反应的趋势，证实了氢转移反应在催化裂化脱硫中所起的作用。

In Chapter 2, introduces elementary theory and quantum chemistry computation methods, which mainly contained the reaction surface, crossing rules of the potential energy surfaces, tradition transition state theory, spin-orbit coupling mechanism and rules for intersystem crossing.

第二章简要地介绍了量子化学计算方法，主要包括量子化学基本理论和反应势能面、势能面相交与不相交规则、过渡态理论和系间窜越的选择规则。

Aggregation Behavior and the Hard Water Resistant Ability of Linear Alkylbenzene Sulphonate :MesoDyn Simulation and Quantum Calculation Study The quantum calculation and MesoDyn simulation were combined in this paper, the Critical Micella Concentration difference of LAS and AS was studied by the simulation, and aggregation morphology as well as aggregation behavior of linear alkylbenze sulfonate in aqueous solution was investigated by MesoDyn simulation in the presence and absence of shear.

水溶液中直链烷基苯磺酸盐的介观模拟及其抗硬水能力的量子化学计算将介观模拟和量子化学计算方法相结合，通过模拟的方法从介观角度研究了十二烷基苯磺酸盐和十二烷基磺酸盐临界聚集浓度的差异，考察了LAS水溶液体系的聚集形貌以及微相分离时发生的复杂行为。

One of the Holy Grails of quantum mechanical calculation is to predict properties of matter prior to experiments, to examine the physical properties or processes that are inaccessible by experiments.

量子化学是研究分子微观结构、性质和分子间相互作用的基础学科，在近20年中，量子化学的基础理论和计算方法取得了显著进展。

In this paper, the flotation rule and behavior of kyanite一group polymor-phous minerals were studied in modified Hallimond tube in detail,Further-more, the energy change of collector/mineral systems before and after ad-sorption and the net charge densities of the atoms on the minerals surfaceswere calculated by use of quantum chemistry ,The flotability of the mine-rals was successfully explained.

进一步应用量子化学CNDO／2法计算了捕收剂在矿物上吸附的能量变化和矿物表面原子的电荷分布密度，并根据量子化学计算结果成功地解释了蓝晶石类同质异相矿物的浮选规律。

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％。