铱

This paper is focused on the preparation, characterization of metal clusters and theircatalytic performance in the enantioselective as well as stereoselective hydrogenations. It iscomposed of the five parts as follows: Chapter 1 A review was given on the two most studied enantioselective systems—Ni/TA and Pt/cinchona system, including some recent progress.

本论文研究了铂、铱纳米金属簇在α-酮酯、α-二酮不对称氢化中的催化性能及金属离子在α-二酮立体选择性氢化中的修饰作用，主要分为以下几部分：第一章对多相不对称催化体系一Ni／TA和Pt／cinchona及其一些最新进展作了较系统的评述；同时简要介绍了纳米金属簇的特性及其在催化中的一些应用。

On some occasions, we would have to use Iridium satellite phones for communication.

在某些情况下，我们必须用铱卫星电话交流。

The device based on the copolymer with 1% molar fraction of Ir complex in the polymer had a peak luminous efficiency of 2.89 cd/A, and the maximal luminance of 1689 cd/m^2 with the configuration of ITO/PEDOT: PSS/emissive layer/Ba/AlPEDOT: poly(3, 4-ethytenedioxythiophene, PSS: poly.

基于铱配合物摩尔分数为1%的聚合物发光器件（器件结构：ITO/PEDOT： PSS/emissive layer/Ba/Al，PEDOT：聚（3， 4-亚乙基二氧噻吩），PSS：聚苯乙酸磺酸钠）在电流密度为40×10^(-3)A/平方公分时，最大电流效率达到2.89cd/A，器件的最大亮度达到1689cd/平方公尺，色坐标为(0.34， 0.59)。

The Iridium luminaire family includes CosmoPolis and ...

铱灯具系列包括大都会和。。。

Chapter 5 describes the synthesis of iridacycles based on [4+1] cyclization reaction.

第五章主要研究基于[4+1]关环法的铱杂环化合物合成。

Most of previous studies focused on the dosimetry around an Iridium-192 in water.

研究结果显示，铱192射源在近接治疗的剂量评估上仍有改善空间。

This story, though, raises the question of why there is but a single ejecta layer of iridium and shocked quartz in late Cretaceous rocks around the world.

然而，这却引发了一个问题：为什么全世界只有一个白垩纪后期的铱和受震石英熔岩层。

Lanthanides belong to the sixth cycle of the periodic table Ⅲ B family, are all solid metal, they are La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, holmium, erbium, thulium, ytterbium, and lutetium were 15 kinds of metals and their periphery are two layers of electronic 5d16s2, while the peripheral third layer f orbital but never zero to 14, so the external electronic structure of 4f0-145d16s2, and therefore these elements in oxidation number are to 3, very close chemical properties, extraction, when it is difficult to separate them they are mostly multi-element mineral mix, more difficult to increase refining, and their atomic number of 57-71, one by one to increase the number of protons the nucleus, and thus extranuclear electron of gravity is also growing, so that atomic radius decreases with increasing atomic number Z, which makes lanthanides contraction, ionic radius is also reduced, which also makes Zr, Hf, Nb and Ta, Mo and W, the atom and ionic radius very close to each other they also determine a similar nature, resulting in difficult separation, also the tribe Ⅷ of the fifth cycle, ruthenium, rhodium, palladium, and the sixth cycle, osmium, iridium, platinum is very similar in nature, thus The six elements, said platinum group elements.

镧系元素属于周期表第六周期中ⅢB族，全部是固体金属，它们是镧、铈、镨、钕、钷、钐、铕、钆、铽、镝、钬、铒、铥、镱和镥共十五种金属元素，它们的外围两层的电子均是5d16s2，而外围第三层的f轨道电子却从零增加到14个，所以外围电子结构为4f0－145d16s2，而使这些元素氧化数均为＋3，化学性质极为接近，提炼时很难分开，它们的矿石又大多是多种元素混在一起的，更增加提纯难度，它们的原子序数为57－71，核内质子数逐个增加，因而对核外电子引力也不断增强，使原子半径随原子序数Z增加而减小，这就使镧系元素收缩、离子半径也缩小，这也使得Zr和Hf，Nb和Ta、Mo和W等原子和离子半径都很接近、也决定了它们彼此性质类似，以致难以分离、也使第Ⅷ族中第五周期的钌、铑、钯和第六周期的锇、铱、铂在性质上极为相似，因而称这六个元素为铂系元素。

Methods Recording electrode fabricated from external insulated wire 60μmin diameter（95%Pt-5%Ir alloy）,was implanted directly by microsurgery technique into the fascicle of the sciatic nerve of rabbit.

用显微外科操作技术将直径60μm的95%铂、5%铱合金表面绝缘的金属丝直接插入家兔坐骨神经一神经束中作为记录电极。

However, the content of iridium in the rock formation is 200 times the normal concentration.

然而这个岩层中的铱含量是正常含量的200倍。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。