三键

Starting from 3-benzoyl-5-formyl-indolizine, 3-benzoyl-5-(2'2'-diacetylethenyl)-indolizines and analogs were obtained by the 〓mediated aldol condensation or Wittig reaction. These compounds,promoted by low-valent titanium, gave highly functionlizedcycl[3,2,2]azine derivatives. The coupling reaction proceeded betweenthe carbonyl group and the carbon-carbon double bond, a rare example inMcMurry reaction.

我们以3-苯甲酰基-5-甲酰基中氮茚为原料，通过三碘化钐促进的aldol反应和Wittig反应制备了3-羰基-5-羰基乙烯基中氮茚，随后经低价钛还原偶联，没有生成正常的分子内羰基-羰基偶联产物，而是得到反常的羰基与α，β-不饱羰基的双键偶联产物，较高收率地得到了含多官能团的CycI[3，2，2]azine衍生物。

Huwentoxin-Ⅱ is a neurotoxin purified from the venom of the Chinese bird hunting spider Selenocosmia huwena, which contains 37 amino acid residues including 6 cysteine forming three pairs of disulfide.

虎纹捕鸟蛛毒素Ⅱ（huwentoxin-Ⅱ，HWTX-Ⅱ）是从虎纹捕鸟蛛Selenocosmiahuwena毒液中纯化出的新型多肽神经毒素，含有37个氨基酸残基，包括6个半胱氨酸，形成了三对二硫键。

Trigonal - Three-point core, bond angle 120

三角形-三点核心，键角120

The ligands are tridentate and bridge across the Ag〓 triangles with bridging S atoms occupying all three edges of these trans-oriented triangles.

三齿配体通过硫原子形成了跨过Ag〓三角平面的三条边的桥键。

In order to probe the existence of nonthermal microwave effects, four synthetic transformations (Diels-Alder cycloaddition, alkylation of triphenylphosphine and 1,2,4-triazole, direct amide bond formation) were reevaluated under both microwave dielectric heating and conventional thermal heating.

为了探测非能微波效应的存在，四种合成转化反应（Diels-Alder环加成、三苯基膦和1，2，4-三唑的烷基化、酰胺键的直接合成）在微波介电加热和传统热加热两种情况下的重新评价。

A water-soluble gold nanoparticle was prepared with trisodium citrate by reduction method, and using cystine as a self-assembled molecule, three dimensional net structure of gold nanoparticle with cystine was obtained.

用柠檬酸三钠还原法制备了水溶性金纳米粒子，粒子的平均粒径为4.5 nm，它与胱氨酸作用后，胱氨酸利用双硫键在其表面成功地进行了自组装，获得了金纳米粒子-胱氨酸的三维网状结构。

The interaction between MT and AA was expressed by infrared spectra, the functional groups of -SH in MT had lone pair electrons, which could formπ-πwith -C=O in AA. The equilibrium binding experiment and Scatchard analysis showed, at least three kinds of binding sites would exist when MT-imprinted polymer formed, the most adsorption capacities were 3.3896mg/g, 0.9362mg/g, 1.6583mg/g respectively; most terminal thiolate sulfurs in MT were polymerized as binding sites in the process of polymerization, which could observed from TEM, binding capability of other thiolate sulfurs was weak since spatial hindrance existed.

采用红外光谱研究了加入金属硫蛋白后功能单体丙烯酸官能团谱峰的变化，结果表明金属硫蛋白分子中的-SH与丙烯酸中的C=O在氯仿溶液中能形成π-π键，由聚合物的吸附特性和Scatchard分析可以得出，金属硫蛋白印迹聚合物至少存在三种结合位点，其高、中、低的最大吸附量分别为3.3896mg/g、0.9362mg/g、1.6583mg/g；通过透射电镜可以观察到，金属硫蛋白在聚合过程中主要以分子两端的巯基作为结合位点，不同位置的巯基受到的空间位阻不同，导致产生了三种不同的结合位点。

Determined electric conductivity of Rare Earths salt ErCl 3、DyCl 3、NdCl 3 and YCl 3 in H 2O at 293K, using formula calculated the molar conductivity of Rare Earths salt in H 2O , and discussed the effect of the electric conductivity and the molar conductivity of Rare Earths salt in H 2O with concentration at 293

天然Ⅰa型金刚石在垂直于( 10 0 )，( 110 )和( 111)三个方向上定向显微红外光谱的定量比较分析表明：水、片晶和C—C键在以上三个方向上所测得的浓度是不相同的。

It was not a simple system with three different spline sizes, three different thread sizes, and eight different spacers.

这不是一个有三个不同的花键尺寸，三种不同的螺纹尺寸，和8个不同的间隔简单的系统。

Headlines features of the 5500 include an instant swap key for switching the phone into different modes, a 3D sensor which enables pedometer functionality for sports tracking and an alternative interaction method, text to speech capabilities for various functions, and an active (stainless steel and rubberised casing) orientated design.

突出的功能包括快速功能切换键以在三种模式间切换，一个三维感应器从而能让手机用作步数计，一个可供选择的互动方法，文本阅读能力，以及面向户外运动的设计。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。