查询词典 vortex atom

Two special structural features of the sulfonium salt were proved to stabilize its corresponding ylide and depress the 2,3-sigma rearrangement. One is that there is a trimethylsilyl in the end of the allylic double band. This silicon atom can stabilize a α-carbon anion and the corresponding ylide. Another is that there is hydroxy group in the beta-position of sulfonium atom. The oxygen of this hydroxy group may stabilize the sulfonium cation.

为了稳定生成的烯丙基硫叶立德，并抑制它的2， 3-sigma 重排反应，在硫叶立德结构上做了两方面的考虑：一是在烯丙基双键的未端引入硅基，利用硅原子对 a -碳负离子的稳定作用来稳定烯丙基硫叶立德；二是在硫原子的 b -位引入羟基，利用羟基氧对硫正离子的作用来稳定硫叶立德。

Significant progress has been made by Dalibard,Dupont-Roc and Cohen-Tannoudji in 1982,who argued that there exists a symmetric operator ordering between the operators of atom and field that renders the distinct contributions of vacuum fluctuations and radiation reaction to the atom\'s spontaneous emission and energy shift separately Hermitian.

这种不确定性的根源来自于相互作用哈密顿量中原子和场算符的排序问题。1982年，法国物理学家Dalibard，Dupont-Roc和Cohen-Tannoudji提出原子和场算符对称排序的方法，从而消除了这种不确定性，使得真空涨落和辐射反作用对原子自发辐射和能级移动的贡献都是厄米的。

Afterwards, using the spherical tensor form of many-electron atom Hamilton and the irreducible tensor theory, the relativistic and fine-structure energy correction to the non-relativistic energy of Boron-like atoms in the ground and the first excited states have been further investigated. A theoretically analytic way has been given as to the calculation of all the radial integrations and spin summations, which concern interactions such as orbit-orbit, spin-orbit, spin-spin and spin-other-orbit. Therefore, the whole process of calculating the many- electron atom energy structures has been explicitly revealed and the results are relatively precise and satisfactory.

在此基础上，利用多电子原子哈密顿算符的球张量形式和不可约张量理论，进一步研究了类硼离子基态和第一激发态非相对论能级的相对论修正和精细结构，给出了轨道-轨道、自旋-轨道、自旋-自旋、自旋-其它轨道等相互作用所涉及的所有角向积分和自旋求和的解析计算方法，清晰地展示了多电子原子结构计算的过程，得到了较为精确的理论计算结果。

CH3OH could attack the phosphor atom in 1,3,2-dioxaphopholane of compiound (1) to give O-methyl O-hydroxyethyl-O-phthalimidoethyl thiophosphate in 85% yield; in the presence of potassium hydroxide aryl selenol could attack the carbon atom in 1,3,2-diox-aphopholane of the cyclic phospholipid conjugate of N^1-(2-furanidyl)-N^3--5-fluorouracil to give the corresponding product of ring-opening in high yields.

在室温下，以异丙醇作溶剂，苯硒酚与化合物2不反应。在氢氧化钾存在下，以异丙醇／水作溶剂（体积比20：1，在室温下，硒酚可以有效地进攻中化合物2中1，3，2-二氧磷杂环戊烷中的碳原子生成相应的开环产物。按照这一反应条件，顺利实现了硒酚对N^1-（2-呋喃基）-N^3-羟烷基-5-氟脲嘧啶硫代环甘油磷脂缀合物的亲核开环，生成甘油骨架的端碳原子上带有芳硒基新颖的磷脂核苷缀合物。

Ta atom is triangularly coordinated and M atom is trigonal-pyramidally surrounded by Te atoms.

Ta具有三角形的Te配位， M具有三角锥的Te配位。

In this work, taking into account the molecular fraction and the presence of the 4-atom, we calculated the Gibbs free energy and studied, the influence of the percent of 4-atom on the parameters of the triple point and the critical point.

本文进一步考虑4-原子的存在，计算了有空格点存在时系统的吉布斯自由能，研究了4-原子所占百分数对三相点t_t，P_t值以及临界点t_c，p_c值的影响，获得了具有三相点和临界点的完整相图。

Structural and density of state analysis shows the interaction of O atom and surface is the total contribution of valance orbital of O atom and hybridized surface orbital of NiTi alloy.

态密度分析和结构分析表明，O原子与表面的相互作用主要是由O原子价轨道和NiTi合金杂化表面轨道贡献。

Each of the four valency electrons of the carbon atom is shared with one of a hydrogen atom.

碳原子的四个价电子都各与氢原子的一个价电子共用。

In such structure, each In atom is bonded with two Si substrate atoms and one neighboring In atom, thus all three valency of In are saturated.

在这种再构结构中，每个 In 原子与两个衬底 Si 原子及一个相邻的 In 原子形成共价键。

In the structure of complex (1), two L valine molecules chelated with Cu in five member ring by the coordination of amino nitrogen atom and carboxylate oxygen atom with the center ion.

在自组合过程中，配体与配位中心离子以自发和直接的配位络合方式能够产生精致的超分子晶体结构 [1，2 ] 。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。