三原子的

The effects of excess air coefficient and cylinder pressure on these spectra are also studied. The experimental resultS show that the three different combustion phases in a gasoline engine have different combustion characteristic spectra: a large number of atoms, molecules, ions and radicals which are in their excited states are existing during the ignition process, with the development of the combustion, the spectra intensities of CH, C2 radicals increase rapidly.

实验结果表明，汽油机三个不同的燃烧阶段具有不同的燃烧光谱特征：着火过程中，存在着大量的处于激发态的分子、原子、离子、自由基等活化中心的束缚态光谱，随着燃烧发展，CH、C2自由基的光谱强度明显加强；当减小过量空气系数时，光谱强度变弱并且着火延迟期增长；自由基特征光谱的光强变化曲线可以反映它们在燃烧过程中的浓度变化。

A newly developed three-dimensional holographic vector of atomic interaction field（3D-HoVAIF）was used to describe the chemical structure of 200 aromatic compounds with toxic effect on Tetrahymena pyriformis.

采用新型的的三维原子场全息作用矢量（3D-HoVAIF）研究了200种芳香化合物的化学结构与其生物毒性的定量构效关系。

This thesis studies the analytical methods of determination of Leucogen and Hydroxymethylnicotinamide by Ultraviolet and Atomic Absorption Spectrscopy.

本文研究了分光光度法和原子吸收光谱法测定利血生及羟甲基烟酰胺的分析方法，提出了利血生的三种测定方法和羟甲基烟酰胺的一阶导数峰-零法的测定新方法，并用于实际样品的测定，获得满意结果。

In this method onlydihedral angles were selected as independent variales,a proper target function was minimized by loacl-to-globular optimization,thus these dihedral angles andthe coordinates of six kinds of the backbond atoms (N,HN,Cα,IIα,C′,0) were calculated.

这种方法把肽平面之间的二面角当做独立变量，通过从局部到整体逐渐最优化的方法使适当构造的目标函数最小，计算出这些二面角，以及主链每个残基上六种原子N、H%%^^N%%^^、C%%^^α%%^^、H%%^^α%%^^、C′、O的空间坐标，绘出蛋白质分子的溶液三维结构图案，并成功地把这种方法编写成计算程序DISNMA，且以碱性胰蛋白酶抑制剂为标准结构，得到了很好的验证。

X-ray analyses indicate that lattice parameters decrease due to Cu-doping; while XPS results show that Cu-doping leads to positive chemical shifts of the Cu 2P1/2 and La 3d5/2 and 3d3/2 levels, implying that Cu-O and La-O bondings are strengthened and their bond lengths are shortened; while magnetization measurements show that after 8 hours' Arannealing, the Neel temperature of Cu-rich sample is about 31K higher than that of the sample without Cu doping, indicating that the three-dimensional antiferromagnetic correlation is enhanced.

结合各种分析手段认为，掺杂的铜原子部分替代了 La 位，也有填补 CuO2面的 Cu 空位和在晶界形成微量第二相的可能占位情况，使得铜的掺杂取得了增强二维特别是三维反铁磁交换作用的效果，促进了La2CuO4+δ系统的相分离。

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 ESR data of 3f suggest that Cu〓 is in a distorted tetrahedral field, that is to say, Cu〓 is coordinated to three tertiaty nitrogen atoms and one chloride anion.

为了探测模型化合物中Cu〓的配位情况和几何构型，采用相同的方法合成和表征了杂双核化合物3f，ESR信号结合质谱信息表明杂双核化合物3f中，Cu〓是四配位的，即它与一个C1〓和三个叔铵氮原子配位而处于变形的四面体场中。

NiRs are divided into two different types based on their prosthetic groups, namely heme-containing nitrite reductases (cd1-NiRs) and Copper-containing nitrite reductases.

Cu-NiRs呈三聚体结构，每个单体都含有两种类型的铜原子，它们在酶催化过程中起着传递电子的重要作用。在催化过程中，Cu-NiRs中部分残基的结构变化有利于催化反应的进行。

The three pure component parameters for alkanes were determined by fitting the saturated vapor pressure and liquid density data, near linear relations were observed between the parameter values and the carbon number.

由拟合正构烷烃的饱和蒸汽压和液相密度所确定的三个纯组分参数与烃的碳原子数呈良好的线性关系。

The Small Magellanic Cloud pictured above actually spans 15,000 light-years or so and contains several hundred million stars.

但这张远视图片中生动的颜色是人工绘色的，是基于通过狭窄滤波片的三种曝光，每一个滤波片记录下气态星云中特殊原子放射出的光。

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％。