Heavy water is heavy because the hydrogen in it weighs twice as much as ordinary hydrogen (it has a proton and a neutron in its nucleus, instead of just a proton).
重水之所以重是因为水中氢的重量是普通氢的两倍(它的原子核中有一个质子和一个中子,而不仅仅是一个质子)。
This work prepared the way for the discovery of the neutron by Sir James Chadwick and, above all, for the discovery in 1934 by Irène and Frédéric Joliot-Curie of artificial radioactivity.
这项工作为詹姆斯·查德威克爵士发现中子铺平了道路,尤其是为伊莲娜和弗雷德里克·约里奥特·居里在1934年发现人工放射性奠定了基础。
They would form helium and a subatomic particle, called a neutron.
聚变后形成氦以及一种称为“中子”的亚原子粒子。
A deuterium atom is a hydrogen with an extra neutron in its nucleus.
重氢是原子核中多一个中子的氢。
A spinning neutron star is tied to a mysterious tail — or so it seems.
一个旋转的中子星拖出了一条神奇的尾巴,至少看起来是这样的。
A thimbleful of a neutron star would weigh over 100 million tons.
一颗中子星很微量的一部分,重量也会超过1亿吨。
Each proton (or neutron) has about two thousand times the mass of an electron.
每一个中子或者质子的质量都是一个电子的两千倍。
One teaspoonful of material from a neutron star would weigh a billion tonnes.
一茶匙中子星上的物质重达十亿吨。
As an added safety measure, they injected neutron-absorbing boric acid into the core.
同时向堆芯注射可吸收中子的硼酸来作为一种附加的安全措施。
When a neutron inside an atom decays, it produces a proton, an electron, and a neutrino.
原子内的一个中子衰变后会产生一个质子、一个电子和一个中微子。
But sometimes a cosmic ray will collide with a nitrogen atom, giving it an extra neutron.
但有时宇宙射线会撞击氮原子,赋予它一个额外的中子。
This generator drives an energetic wind of electrons and ions away from the neutron star.
这个发电机制造出强劲的能量风,把电子和离子吹离中子星。
So instead of looking at many neutron stars, researchers needed to look at only this one.
因此,不同于以往观察许多中子星,研究人员们只需要观测这一个中子星即可。
One step from becoming black holes, neutron stars are thedensest objects in the universe.
中子星是宇宙中密度最高的天体之一,一茶匙的重量便高达数十亿吨,距离成为黑洞只有一步之遥。
In the same way the proton and neutron should also have their corresponding antiparticles.
同样地,质子和中子也应该有对应的反粒子。
When the commonest isotope of iron (56Fe) absorbs a neutron, the result is not radioactive.
当最普通的铁(56Fe)的同位素吸收了一个中子,生成物无放射性。
Known as "neutron activation," the technology provides precise results, even on tiny samples.
这种被称作“中子激活分析”的技术甚至能对微小的样本提供精确的结果。
Rutherford had put forward some tentative ideas that there might be a third particle - a neutron.
卢瑟福提出一些试探性的想法认为也许会有第三种粒子——中子。
For example, spinning neutron stars called pulsars emit clocklike streams of electromagnetic pulses.
例如,被称为脉冲星的自旋中子星发射出像钟摆一样的电磁脉冲。
Likewise, it can't go on forever because Cas a would get far colder than neutron stars generally do.
同样,这种效应无法永远持续下去,因为否则Cas a将远比普通中子星的温度低。
It also bodes ill for the prospect of fusion using helium-3, a rare helium isotope that is missing a neutron.
这也预示着,利用氦- 3这种缺少一个中子的稀有的氦同位素进行核聚变的前景很黯淡。
But they didn't have to scoop a chunk of neutron degenerate matter from the surface of a real neutron star either.
但他们也并不需要从一颗真正的中子星表面挖来一块中子星简并物质。
Magnetars are a type of neutron star which has a magnetic field a million billion times stronger than the Earth's.
磁星是一类磁场比地球磁场强千亿倍的中子星。
These rods, made of neutron-absorbing materials such as boron, mop up excess neutrons and quench the chain reaction.
这些控制棒,由能够吸收中子的物质——硼制成,它吸收多余的中子,使链式反应停止。
Magnetars are a type of neutron star? An object so dense its protons and electrons have merged to form neutrons.
磁星是中子星的一种,它的密度非常大,其质子和电子被迫结合形成中子。
Now, two teams of physicists say they have more direct evidence for superfluidity in the heart of a neutron star.
现在,两个小组的物理学家宣称他们掌握了中子星核心中超流的更直接的证据。
After the supernova, the leftover matter could either have collapsed into a black hole or an extremely dense neutron star.
超新星爆发以后,剩余的物质可能塌缩为一个黑洞,也可能形成一颗密度极大的中子星。
After the supernova, the leftover matter could either have collapsed into a black hole or an extremely dense neutron star.
超新星爆发以后,剩余的物质可能塌缩为一个黑洞,也可能形成一颗密度极大的中子星。
应用推荐