查询词典 F-22

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。

Furthermore, in the entrance section, again, ratio d/l and ratio h/f are between 10% and 60%.

此外，在入口部分，比例d／|和比例h／f还处于10％和60％之间。

The F ratio is assumed to be unchanged when using multiple antenna elements.

假定 F 比率在使用全向天线元素时是不变的，这种假定基于系统中智能天线的全面部署这一事实。

Thereby F/T-PSA ratio may be useful for the differentiation between BPH and prostate cancer.

因而，F/T-PSA测定可有助于BPH与前列腺癌的鉴别诊断。

In this paper, the relationship between the fatigue crack front straightness S t and fatigue loading ratio f were explored.

通过实验，研究了疲劳裂纹前沿平直度 St与疲劳载荷比 f 之间的关系，发现两者高度正相关，为预制具有平直裂纹前沿的疲劳裂纹提供了有效的途径和方

For the mathematically inclinded, the sweet spot's diameter is proportional to the cube of the f/ratio.

从数学计算看，甜点的直径与f/焦比的立方成正比。

The reason for this is that ratio F/D determines the angle the edges of the parabola are seen from the focus.

原因就是F/D的比率限定了抛物线焦点到边缘的角度。

His first camera had an aperture of about 360mm or 14.5 in diameter, and a focal ratio of f/1.75. It is now housed in a museum at the Hamburg Observatory .

他的第一个相机的光圈约三百六十零毫米或14.5 ，直径，和一个焦点的比例f/1.75 ，这是现在住在一个博物馆在汉堡天文台。

The ratio F/D is also crucial in determining the characteristics of the feed that will illuminate the dish.

在决定典型照射馈源时，F/D的比率也是决定性因素。

In this paper, the elementary concepts of complex Riesz space and complex f -algebra are introduced first.

本文首先引人了复Riesz空间和复f-代数的基本概念。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。