Neutrons have no charge and are constituents of the atomic nucleus . they are very penetrating and can only be stopped by hydrogen - rich materials , such as water or paraffin 中子不带电荷，是组成原子核的粒子之一，穿透能力极高，只有水或石蜡这些含有大量氢原子的物质，可以阻隔中子。
Neutrons have no charge and are constituents of the atomic nucleus . they are very penetrating and can only be stopped by hydrogen - rich materials , such as water or paraffin 中子中子不带电荷，是组成原子核的粒子之一，穿透能力极高，只有水或石蜡这些含有大量氢原子的物质，可以阻隔中子。
A structure the size of an atom represents a fundamental limit : to make anything smaller would require manipulating atomic nuclei ? essentially , transmuting one chemical element into another 单原子的结构是个基本极限：若要做得更小，基本上就得操控原子核了，这可是把一种化学元素转换为另一种。
An example of energy contributing to mass occurs in the most familiar kind of matter in the universe ? the protons and neutrons that make up atomic nuclei in stars , planets , people and all that we see 能量贡献给质量的例子，就发生在宇宙中我们最熟悉的物质上，那就是构成恒星、行星、人以及我们所见万物的质子与中子。
These energy levels are determined by how tightly the atomic nucleus holds the electrons , which depends on the strength of the electromagnetic force between them ? and therefore on the fine - structure constant 能阶是由原子核拉住电子的松紧程度所决定，而这又取决于能阶之间的电磁力强度，因此便和精细结构常数关系密切。
The main equipment of the ion electrostatic accelerator is in good condition . if it is used again it will be the important implement of science research about atomic nucleus physics , biology aberrance and material denaturalization 它的主要设备情况良好，一旦恢复使用，将成为原子核物理，生物诱变，材料改性等科研工作的重要工具。
At the time , the theory was regarded as a failure ; it did not achieve its goal of explaining the atomic nucleus , and veneziano soon shifted his attention to quantum chromodynamics , to which he made major contributions 当时，这个理论被认为是失败的；它并没有达成解释原子核物理的目标，而维纳齐亚诺很快就把注意力转移到量子色动力学，并对其做出了主要的贡献。
For example , a single electron in an unexcited atom is pictured classically as a particle moving in a circular trajectory around the atomic nucleus , whereas in quantum mechanics it is described by a static , spherically symmetric wavefunction surrounding the nucleus 例如，单个电子在不活跃原子里被经典描述为粒子围绕原子核圆形运动，但是在量子力学里它通过用静止、围绕核子的球对称波函数来描述。
Discusses in detail the microscopic nature of various physical quantities characterizing the intrinsic attributes of hydrogen atom to prove that the hydrogen atom ' s quantum energy , the inner quantum orbital momentum of electron and the relative quantum distance between atomic nucleus and electron all relate to the quantum state of the atomic system 摘要阐述了表征氢原子内在属性的各种物理量的微观本质，证明氢原子系统的量子能量、系统内部电子的量子轨道动量及原子核和电子的量子相对距离均与原子系统所处的量子状态有关。
