金属元素

A soft silver-white ductile metallic element; the most electropositive and alkaline metal .

一种质地柔软的银白色韧性金属元素，是最具正电性与碱性的金属。

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。

A hard gray lustrous metallic element that is highly corrosion-resistant; occurs in niobite and fergusonite and tantalite.

一种坚硬有光泽的灰色金属元素，抗腐蚀性极强，见于铌铁矿、褐钇铌矿和钽铁矿中。

Ferromanganese nodules formed under different genetic conditions uptake different transition metals.

在不同生成环境下生成的铁锰结核吸收不同的过渡金属元素。

A white, crystalline, brittle, highly diamagnetic metallic element used in alloys to form sharp castings for objects sensitive to high temperatures and in various low-melting alloys for fire-safety devices.

铋：白色、晶状、易碎、高度抗磁的金属元素，用于高温敏感物体的合金中，以铸成锋利物件，多种用于防火安全设施的低熔点合金。

For both kinds of flocculent sludge,the diameter of the formed granular sludge is 0.5 to 1 mm and SVI is 30 mL/g,but the differences in the sludge...

此外，在污泥由絮状向颗粒状转化的过程中，其含水率和部分金属元素的含量明显降低。

A soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime.

一种软质的银色稀土属金属元素，见于硅铍钇矿、独居石和磷钇矿中。

To accomplish this, the researchers used gallium, a metal ery similar to iron.

为了阻断细菌对于铁元素的摄入，研究人员采用了一种与铁非常相似的金属元素－镓。

A ductile silvery metallic element that is resistant to corrosion used in alloys occurs in pentlandite and smaltite and garnierite and millerite .

一种硬而软的银色金属元素，可锻造，抗腐蚀，用于合金中，见于硫镍铁矿，砷钴矿，硅镁镍矿，针镍矿中。

A hard malleable ductile metallic element that is resistant to corrosion used in alloys occurs in pentlandite and smaltite and garnierite and millerite .

一种硬而软的银色金属元素，可锻造，抗腐蚀，用于合金中，见于硫铁矿，钴，硅镁，针中。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。