每日一词：量子理论 (Quantum theory)

在19世纪末，经典物理学已经无法解释许多与电磁辐射相关张元素的各种观察结果。1900年，德国物理学家马克斯·普朗克提出，电磁辐射——包括光——不是作为一个连续的波发射出来的，而是作为被称识图搜索为量子的离散能量束。普朗克将每个量子的能量（E）与波的频率（f）联系在一起，公式海城大悲寺为E= hf，其中h是普朗克常数。

小猪佩奇头像其中一个更令人费解的现象是光电效应，即当光或其他形式的电磁辐射照射到某些金属时，会发射出电子。1905年，阿尔伯特·爱因斯坦提出，只有在普朗克的光量子理论正确的情况下，才能解释这种效应。在光电效应的情况下，光的行为不是作为一种波，而是作为一种粒子流（现在称为光子）。20年后，法国物理学家路易·维克多·德·布罗格利（1892-1987）提出，电子也表现出类似的波粒二象性。

普朗克的想法促使丹麦物理学家尼尔斯·玻尔在1913年提出，在原子内部，电子只能在某些允许的轨道上移动，每个轨道都有自己的能量级别。当一个电子从一个较高的能级跃迁到一个较低的能级时，辐射会以离散的沙发品牌排行榜前十名量子形式释放出来。

1927年，德国物理学家维尔纳·海森堡提出了他著名的不确定性原理。牛顿力学认为，一个物体的位置和动量可以同时测量，而且精确度可以达到无限高。而不确定性原理指出，在原子和亚原子尺度上，这是不可能的，因为观察的行为本身改变了结果。

量子理论打破了许多如因果关系之类的概念框架，看起来与我们的常识相悖。但它已经有了无数的实际应用，尤其是在现代计算技术基础——半导体领域。

Towards the end of the 19th拉菲堡 century, observations of various phenomena relating to electromagnetic radiation raised questions that classical pps皮肤美白hysics seemed incapable of answering. Then in 19林天宏00 the German physicist Max Planck suggested that electromagnetic radiation - including light -is not emitted as a continuous wave, but as discrete bundles of energy called quanta. Planck linked the energy (E) of each Quantum to the frequency of the wave (f) in the equation E= hf, where h is the so-called Planck constant.

One of 自制飞机杯the more puzz成人高考录取通知书ling phenomena was the photoelectric effect, in which electrons are emitted when light or other forms of electromagnetic radiation strike certain metals. In 1905, Albert Einstein pr返利appoposed that the effect could only be explained if Planck's quantum theory of light was correct. In the case of the photoelectric effect, light behaves not as a wav香港面积多少平方公里e, but as a stream of par循环水ticles (now known as photons). Two decades later, the French physicist Louis Victor de Broglie (1892-1987) suggested that electrons display a similar wave-particle duality.

Planck's idea prompted the Danish physicist Niels Bohr to suggest in 1913 that inside the atom (see page 175), electrons can only move in certain permitted orbits, each with its own energy level. When an electron jumps from a hi炼铁技术gher to a lower energy作文在线 level, radiation is released in discrete quanta.

In 1927, the German physicist Werner Heisenberg de阳光农场vised his famous uncertainty principle. Newtonian mechanics assumes that the position and momentum of a body can be measured simultaneously with infinite accuracy. The uncertainty principle states that at the atomic and subatomic scale, this is not possible, because the very act of observing alters the outcome.

Quantum theory, undermining as it d福大考研oes many conceptual frameworks such as causality, may s定价模型eem c宏碁电脑维修ontrary to common sense. But it has been found to have innumerable p鬼4虐ractical applications, not least in our understanding of semiconductors, the basis of modern computing technology.