mean free path

简明释义

平均自由路程

英英释义

例句

1.In a gas, the average distance a molecule travels before colliding with another is known as its mean free path.

在气体中，分子在与另一个分子碰撞之前平均行驶的距离被称为自由程。

2.When designing vacuum systems, engineers must consider the mean free path of particles.

在设计真空系统时，工程师必须考虑粒子的自由程。

3.The mean free path of air molecules is affected by temperature and pressure.

空气分子的自由程受温度和压力的影响。

4.The mean free path can be calculated using the density and cross-sectional area of the molecules.

可以通过分子的密度和横截面积计算自由程。

5.In plasma physics, the mean free path helps predict how particles will interact.

在等离子体物理中，自由程有助于预测粒子如何相互作用。

作文

The concept of mean free path is fundamental in the study of physics, particularly in the fields of thermodynamics and kinetic theory. The term refers to the average distance a particle travels between collisions with other particles. Understanding this concept is crucial for several applications, including gas dynamics, material science, and even astrophysics. In essence, the mean free path provides insights into how particles interact in a given medium, which can influence everything from the behavior of gases to the properties of solids.To elaborate further, let’s consider the behavior of gas molecules in a closed container. Gas molecules are in constant motion, and they collide with one another and with the walls of the container. The mean free path quantifies the average distance a molecule travels before it collides with another molecule. This distance depends on various factors, including the size of the molecules, the density of the gas, and the temperature. For instance, at higher temperatures, molecules move faster, which can increase the mean free path since they spend less time in close proximity to one another.The mathematical expression for the mean free path can be derived from the kinetic theory of gases. It can be expressed as:\[ \lambda = \frac{kT}{\sqrt{2} \pi d^2 P} \]where \( \lambda \) is the mean free path, \( k \) is the Boltzmann constant, \( T \) is the temperature, \( d \) is the diameter of the gas molecules, and \( P \) is the pressure of the gas. This formula illustrates how changes in temperature and pressure can affect the average distance between collisions.In practical applications, knowing the mean free path helps scientists and engineers design better systems. For example, in the field of semiconductor manufacturing, understanding the mean free path of electrons can lead to improved performance of electronic devices. Similarly, in astrophysics, the mean free path of photons in a star can influence its luminosity and temperature.Moreover, the mean free path is not limited to gases; it also applies to liquids and solids. In liquids, the mean free path can help explain phenomena such as diffusion and viscosity. In solids, it can influence the thermal conductivity and electrical properties of materials. Thus, the versatility of the mean free path concept makes it a valuable tool across various scientific disciplines.In conclusion, the mean free path is a key parameter that helps us understand the behavior of particles in different states of matter. By studying the mean free path, we gain insights into the interactions of particles, which can have profound implications in both theoretical and applied sciences. Whether in designing new materials or understanding cosmic phenomena, the mean free path remains an essential concept that bridges multiple fields of study, enhancing our overall comprehension of the physical world.

“平均自由程”这一概念在物理学研究中是基础性的，特别是在热力学和动理论领域。这个术语指的是粒子在与其他粒子碰撞之间的平均行进距离。理解这一概念对多个应用至关重要，包括气体动力学、材料科学，甚至天体物理学。实质上，“平均自由程”提供了关于粒子在给定介质中如何相互作用的见解，这可能影响从气体行为到固体特性的方方面面。进一步阐述，我们考虑气体分子在封闭容器中的行为。气体分子处于不断运动中，它们相互碰撞并与容器壁发生碰撞。“平均自由程”量化了分子在与另一分子碰撞之前的平均行进距离。这一距离取决于多个因素，包括分子的大小、气体的密度和温度。例如，在高温下，分子运动得更快，这可能增加“平均自由程”，因为它们在彼此的近距离停留的时间更少。“平均自由程”的数学表达式可以通过气体动理论推导出来。它可以表示为：\[ \lambda = \frac{kT}{\sqrt{2} \pi d^2 P} \]其中 \( \lambda \) 是“平均自由程”，\( k \) 是玻尔兹曼常数，\( T \) 是温度，\( d \) 是气体分子的直径，\( P \) 是气体的压力。这个公式说明了温度和压力的变化如何影响碰撞之间的平均距离。在实际应用中，了解“平均自由程”帮助科学家和工程师设计更好的系统。例如，在半导体制造领域，理解电子的“平均自由程”可以提高电子设备的性能。同样，在天体物理学中，光子在恒星中的“平均自由程”可以影响其亮度和温度。此外，“平均自由程”不仅仅局限于气体；它也适用于液体和固体。在液体中，“平均自由程”可以帮助解释扩散和粘度等现象。在固体中，它可以影响材料的热导率和电气特性。因此，“平均自由程”概念的多样性使其成为各个科学学科中的宝贵工具。总之，“平均自由程”是一个关键参数，帮助我们理解不同物态下粒子的行为。通过研究“平均自由程”，我们获得了粒子相互作用的见解，这在理论和应用科学中都具有深远的影响。无论是在设计新材料还是理解宇宙现象，“平均自由程”始终是一个桥接多个研究领域的重要概念，增强了我们对物理世界的整体理解。