查询词典 Nb

Recently, great advances were accomplished with arsenic trioxide in the treatment of APL. It has been revealed that As〓O〓 has dual effects on APL cell line NB〓 cell: inducing of apoptosis and improving of partial differentiation.

近年来，国内外学者运用三氧化二砷治疗APL取得了较大进展，研究发现As〓O〓对APL细胞株NB〓细胞具有诱导凋亡和促进不完全分化的双重效应。

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。

Ta,Mo,W,Ti,Nb,the refractory impurity elements,in RE metals are dissolved thoroughly with the addition of fluoric acid,and then determined by ICP-MS.

在稀土金属的冶炼过程中，常用到一些由难熔金属制成的冶炼容器，这样极易引入相应的难熔金属杂质，如Ta、Mo、W、Ti、Nb等。

For Group II gneiss, in contrast, Nb correlates with LILE, but not with LREE.

Nb与LREE的相关性继承了原岩的特征，而不是由变质脱水引起的。

LaNi〓 can be easily activated at room temperature and activated LaNi〓 possesses catalysing effect for the dissociation of H〓, which greatly reduces the energy barrier for dissociation of H〓. Hydrogen passed through LaNi〓 particles, then diffused into the crystal lattices of V、Nb and TiFe alloy and formed hydrogenate.

LaNi〓粒子在室温下很容易活化，活化后的LaNi〓具有了氢分子分解为氢原子的催化作用，降低了氢分子分解为氢原子所必须克服的势垒，氢通过LaNi〓粒子而进入V、Nb、TiFe合金晶格中，形成金属氢化物。

The inserts are large with an iC, inscribed circle diameter, of 19 mm and a thickness of 6 mm with a composition of 5-10 wt-% Co, 5-12 wt-% cubic carbides or carbonitrides of the metals Ti, Ta and/or Nb, and balance WC with a stratified binder phase enriched surface zone 15-40m thick.

刀片很大，其内接圆直径iC≥19mm，厚度≥6mm，其组分为：5-10wt％的Co、5-12wt％的金属Ti、Ta和/或Nb的立方碳化物或者碳氮化物，并且其余为WC，分层富粘结相表面区域为15-40μm厚。

The anomaly range of elements Cr、Ni 、Nb has the direct corresponding relationship with the shape of kimberlite pipe or vein.

Cr、Ni 、Nb的元素异常范围与金伯利岩管的形状有直接的对应关系。

The difference between the lithosome shape, distribution of kimberlite and the physical natures of adjacent rock decides the size, intensity of anomaly and the reflecting degrees. The anomaly range of elements Cr、Ni 、Nb has the direct corresponding relationship with the shape of kimberlite pipe or vein.

综合物化探异常与矿体吻合较好；金伯利岩岩体形状空间分布与围岩的物性差别，决定了异常大小强弱、反映明显程度； Cr、Ni 、Nb的元素异常范围与金伯利岩管的形状有直接的对应关系。

The kimberlite has the intensive magnetism, low resistivity, and high content of Cr、Ni and Nb. Its geophysical and geochemical prospecting anomaly over the earth's surface are mostly shaped in ellipse and ribbon, which is paragenetic with fracture structure.

金伯利岩的分布严格受断裂构造控制，矿体呈管状、脉状，具有成群、结带分布的特征；它具有磁性强、电阻率低、微量元素Cr、Ni 、Nb含量高的特征。

It was found that the partition ratios of Nb, Mn andSi have a close linear relationship with α_ in logarithmic scale.

本文发现，Nb，Mn和Si的平衡分配比同α_的对数值之间有良好的线性关系。

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。