查询词典 helium

Researchers at the University of Alberta in Edmonton, Canada have discovered that combining helium ...

研究人员在艾伯塔大学在加拿大埃德蒙顿发现相结合的氦

Alpha particle s have two positive charges and a mass of four atomic mass units; they are identical to helium nuclei.

因为α粒子有两个正电荷，质量为4，射出后产生的子核的正核电荷和原子序数都比母核小两单位，质量小四单位。

Upon gaining two electrons the alpha particle becomes a helium atom.

粒子获得两个电子后变成了氧原子。

With the discovery of the radio-elements, physicists found themselves for the first time confronted with strange substances, minute generators of radiation endowed with an enormous concentration of energy; alpha rays, positively charged helium atoms, beta rays, negatively charged electrons, both possessed of a kinetic energy which it would be impossible to communicate to them by ''.

由于放射性元素的发现，物理学家们第一次发现自己面临许多陌生的物质——许多具有巨大的浓缩能量的、能够发生辐射的细微物质，如射线，即带正电荷的氦原子小射线，即带负电荷的电子。

Element; discovered by bombarding americium with helium.

一种放射性超铀元素，在用氦轰击镅时发现。

A radioactive transuranic element; discovered by bombarding americium with helium.

一种放射性超铀元素，在用氦轰击镅时发现。注意，注意力集中

The composition of Jupiter is 75% hydrogen and 25% helium by mass, with traces of ammonia, water and methane.

木星的组成是75％，氢和氦25％的质量与氨，水和甲烷的痕迹。

Although helium is nontoxic and inert, it can act as a simple asphyxiant by displacing the oxygen in air to levels below that required to support

尽管氦无毒且不活泼，通过取代空气中的氧，使之下降到维持生命所必须的水平以下，它可以成为简单的窒息物。

Therefore,it is essential for the researchers to study and develop advanced helium gas abstraction technology from natural gas in order to make sure the costeffectiveness of production and to gurantee national helium supplies for many industries.

因此，在保护有限氦气资源的同时，研究开发先进的天然气提氦技术对于提高氦气生产的经济性、保障国家用氦安全和促进我国天然气提氦工业的发展具有重要意义。

For lack of helium gas resource in China,heliumbearing natural gas has become the only source of producing helium gas in industries so there are obvious difficulties in the abstraction technology without costeffectiveness.

含氦天然气迄今仍是工业化生产氦气的唯一来源。我国氦气资源相当贫乏，含量很低，提取难度大，成本高。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。