以后地位 : 注释


工夫:2018-06-05 20:48 阅读:

Scientists have isolated the two different forms of water molecule for the first time. 克日,迷信家们初次乐成别离出两种差别方式的水分子。 Water molecules were known to exist as two distinct "isomers", or types, based on their slightly different properties at the atomic level. 基于原子程度上稍微差别的性子,已知的水分子可以以两种差别的“异构体”范例存在。 By separating out the two isomers, researchers were able to show that they behave differently in the way that they undergo chemical reactions. 经过别离出两种异构体,研讨职员可以证明它们在停止化学反响时可以体现出差别的举动。 In basic terms, water molecules consist of a single oxygen atom bonded to a pair of hydrogen atoms. 简言之,水分子是由两个氢原子和一个氧原子键合而成的。 However, they can be further subdivided based on a property of the nuclei at the hearts of the hydrogen atoms - their "spin". 但是,它们可以依据氢原子中心“自旋”的特性进一步细分。 While they aren't spinning in the sense we would understand, this property of hydrogen nuclei does affect the rotation of the water molecules themselves. 固然这不是我们平凡了解意义上的旋转,但氢核的这种属性的确会影响水分子自身的旋转。

If the nuclear spins of the two hydrogen atoms in water are oriented in the same direction, it is called ortho-water. If they are arranged in different directions, it is known as para-water. 假如水分子中的两个氢原子核自旋以相反的偏向取向,则称为正水分子。假如他们异向自旋,则被称为负水分子。 Given that the isomers are very similar, it has been particularly challenging to separate them out. But co-author Prof Stefan Willitsch and his colleagues succeeded in doing it using electric fields. 鉴于异构体十分类似,以是将它们离开十分具有应战性,但Stefan Willitsch传授和他的同事乐成天时用电场停止了水分子别离。 They were then able to investigate how the different forms of water reacted with another chemical. 随后,他们就可以研讨差别方式的水分子与另一种化学品的反响状况。 They used ultracold diazenylium ions (a form of nitrogen) for this test. The researchers found that para-water reacted about 25% faster with the diazenylium than ortho-water. 他们运用氮离子(一种氮的方式)停止了这项测试。研讨职员发明,与正水分子相比,负水分子化学反响速率进步了25%左右。 Because the rotation of H2O molecules is affected by the nuclear spin, different attractive forces act between the partners in this chemical reaction. 由于水分子的旋转遭到核自旋的影响,以是在这种化学反响中,差别的吸引力在互相反响之间起了作用。 Prof Willitsch said the research could help improve control over other kinds of chemical reaction: "The better one can control the states of the molecules involved in a chemical reaction, the better the underlying mechanisms and dynamics of a reaction can be investigated and understood." Willitsch传授表现,这项研讨可以协助改进对其他范例化学反响的控制:“我们可以更好地控制化学反响中水分子的形态,有利于更深化研讨和了解反响的潜伏机制和动力学。”