金属环

Based on the pioneers' research work, the theoretical calculations have been performed on the interactions between the alkaline earth ions and aromatic systems.

在前人研究一价离子的基础上，进一步研究了金属离子，特别是碱土金属离子与芳环体系的相互作用。

The preparation of epoxides by reaction between alkyl peroxides and olefins catalyzed by high-valent transition metal complexes is one of the most important means of preparation of epoxides.

以高价过渡金属配合物为催化剂，催化烯烃直接环氧化反应是合成环氧化合物的重要途径之一。

ASpheric FeNi nanoparticles with average diameter of about 70 nm were obtained in the system of cetyltrimethyl ammonium bromide/H_2O,while most of the products were nanofilms/rods with the addition of cyclohexane; nearly monodisperse FeNi nanoparticles with average diameter of about 25 nm were prepared in the system of PEG/cyclohexane/H_2O.With the assistance of ultrasonic,a no-surfactant method to 8.5 nm FeCo nanocrystals with high Ms(＞200.5 emu/g)has been developed with economical FeCl_3·6H_2O as iron sources.

a以水合肼为还原剂在十六烷基三甲基溴化铵/H_2O体系中得到了平均粒径约70 nm的FeNi合金球形颗粒，当在此体系中加入环己烷时样品主要形态为纳米膜/棒；于PEG/环己烷/H_2O体系中制备了单分散性较好的平均粒径约25 nm的FeNi合金纳米颗粒，合金纳米颗粒粒径随金属离子浓度减小而减小。

All the actuators of the three-axis turntable are brushless torque motors, all the bearings are aerostatic air bearings, so the friction caused by these elements can be neglected. The main source of friction is the metal-to-metal friction on the slip rings. Hence the "Columb+Viscous+Static" friction model is used here for analysis.

由于三轴转台的驱动系统选用的是无刷电机，轴承则采用的是气浮轴承，轴系上的摩擦力已大大降低，三轴转台上的摩擦主要是滑环轴上金属对金属的摩擦，所以文中选用&库仑＋粘滞＋静摩擦&的摩擦模型来进行分析。

The effects of different center metal ions on third-order NLO properties are discussed. And the conclusion is drawn that the charge transfers from macrocycle π-orbital to metal d orbital make the substantial contributions to microscopic hyperpolarizability.

论文的第三章选择系列酞菁化合物作为研究对象，讨论了不同的中心金属离子对三阶非线性光学性质的影响，确认酞菁共轭环平面上的π轨道到金属离子的d轨道电子跃迁对三阶非线性光学极化率起主要贡献。

The complexing properties of compounds 10a, 10b, 11a and 11b toward alkali metal ions were studied by 〓H NMR titration, ESI-MS, UV-Vis spectra, Fluoresence spectra and liquid-liquid extraction. The results show:(1) the 1:1 complexes were formed.(2) The calix-crown 10a, 11a have a higher selectivity for Na〓 ions, whereas 10b, 11b for K〓 ions.(3) The complexing ability toward alkali metal ions was enhanced when the calix-crown have side arm carbonyl.(3) The coordination of alkali metal ions toward phenoxy, carbonyl and crown ethereal oxygens take place by rotation around the carbon-carbon bond of carbonyl and methylene.

六，用〓H NMR滴定，ESI-MS，UV-Vis，Fluorescence，液-液萃取实验研究了10a，10b，11a和11b对金属离子的配位性质，研究结果表明：1）杯芳烃冠醚衍生物同碱金属离子形成了1：1配合物，化合物10a、11a对Na〓具有较高的配位能力，化合物10b、11b对K〓具有较高的配位能力；2）在杯冠醚环的旁边引入带有羰基氧原子的基团作为侧臂参与配位可以加强对碱金属离子的配位能力；3）金属离子分别同苯酚氧，羰基氧，聚氧醚链氧发生了配位，配位过程中侧链基团涉及到了羰基碳与亚甲基碳的碳碳键的旋转过程。

It is an excellent adhesion improver used in polyamide, epoxy, nitrile, phenol aldehyde adhesive and sealed material to improve the dispersion of pigment and the adhesion to glass, aluminum, iron, also applicable for latex coating such as polyamide, epoxy and acrylic acid type.

优异的粘结促进剂，可用于聚氨酯、环氧、腈类、酚醛粘胶剂和密封材料，改善颜料的分散性并提高对玻璃、铝、铁金属的粘合性，也适用于聚氨酯、环氧和丙烯酸乳胶涂料。

X 6.36(3)? is formed.Liquid-liquid extraction experiments, between twelve heterocyclic thioalkoxycalix[4]arene on the lower rim, fifteen heterocyclic thioacetamidecalix[4]arene on the upper rim and Na~+、K~+、Cs~+、Mg~(2+)、Cu~(2+)、Co~(2+)、Cd~(2+)、Ni~(2+)、Pb~(2+)、Hg~(2+) and Ag~+ picrates, have been carried out and their results are compared.

分别将十二个下沿含有杂环硫烷氧基杯芳烃衍生物和十五个上沿含有杂环硫乙酰胺基的杯芳烃衍生物与Na~+、K~+、Cs~+、Mg~(2+)、Cu~(2+)、Co~(2+)、Cd~(2+)、Ni~(2+)、Pb~(2+)、Hg~(2+)和Ag~+的十一种苦味酸盐进行了离子萃取实验，并对两类衍生物与不用金属离子的萃取能力进行了分析和比较。

One end of its metal shell is fusion connected to ceramic stem and another end is connected with the device to be tested.

金属外壳的一端与陶瓷芯柱相熔封，外壳的另一端与待测器件相接，离子收集极与电子发射体组件相对阳极环同轴非对称安装于金属外壳内。

The shapes of the suspended ring in the present work are also designed to self-center the lens liquid, then influences of different shapes of the suspended rings on the variation of optical power of the meniscus are discussed.

悬浮的金属圆环同时被用来使透镜中的水滴自居中，讨论了具有自居中效应的不同悬浮圆环形状对弯月面光学功率变化范围的影响。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。