网站首页  英汉词典

请输入您要查询的英文单词：

　

单词 Equipartition of Energy
释义

Equipartition of Energy

中文百科

能量均分定理 Equipartition theorem

（重定向自Equipartition of Energy）
图二: 于温度为298.15K（即25°C）时，四种惰性气体分子速度的机率密度函数。图中的四种气体为氦（4He）、氖（20Ne）、氩（40Ar）及氙（132Xe）；左上角的数字代表它们的质量数。这些机率密度函数的量纲为概率除以速度；由于概率无量纲，总量纲能以秒／米表示。
图四：双原子气体的摩尔比热容对温度的理想化曲线图像。高温时比热容跟均分定理预测的(7/2)R一致（其中R为理想气体常数），但当低温时会降至(5/2)R及后来的(3/2)R，这是由于振动及旋转态被“冻结”了的缘故。均分定理的这次失败引出一个只能被量子力学解释的悖论。对大部分分子而言，平移温度Trot比室温要低得多，而Tvib则要比这要大十倍以上。一氧化碳，CO，是一个典型的例子，其Trot ≈ 2.8 K而Tvib ≈ 3103 K。对非常大的分子或不太受束缚的原子Tvib能接近室温（约300 K）；例如，碘气I2的Tvib ≈ 308 K[19]。

在经典统计力学中，能量均分定理是一种联系系统温度及其平均能量的基本公式。能量均分定理又被称作能量均分定律、能量均分原理、能量均分，或仅称均分。能量均分的初始概念是热平衡时能量被等量分到各种形式的运动中；例如，一个分子在平移运动时的平均动能应等于其做旋转运动时的平均动能。

能量均分定理能够作出定量预测。类似于均功定理，对于一个给定温度的系统，利用均分定理，可以计算出系统的总平均动能及势能，从而得出系统的热容。均分定理还能分别给出能量各个组分的平均值，如某特定粒子的动能又或是一个弹簧的势能。例如，它预测出在热平衡时理想气体中的每个粒子平均动能皆为(3/2)kBT，其中kB为玻尔兹曼常数而T为温度。更普遍地，无论多复杂也好，它都能被应用于任何处于热平衡的经典系统中。能量均分定理可用于推导经典理想气体定律，以及固体比热的杜隆-珀蒂定律。它亦能够应用于预测恒星的性质，因为即使考虑相对论效应的影响，该定理依然成立。

英语百科

Equipartition theorem 能量均分定理

（重定向自Equipartition of Energy）
Thermal motion of an α-helical peptide. The jittery motion is random and complex, and the energy of any particular atom can fluctuate wildly. Nevertheless, the equipartition theorem allows the average kinetic energy of each atom to be computed, as well as the average potential energies of many vibrational modes. The grey, red and blue spheres represent atoms of carbon, oxygen and nitrogen, respectively; the smaller white spheres represent atoms of hydrogen.
Figure 2. Probability density functions of the molecular speed for four noble gases at a temperature of 298.15 K (25 °C). The four gases are helium (4He), neon (20Ne), argon (40Ar) and xenon (132Xe); the superscripts indicate their mass numbers. These probability density functions have dimensions of probability times inverse speed; since probability is dimensionless, they can be expressed in units of seconds per meter.
Figure 4. Idealized plot of the molar specific heat of a diatomic gas against temperature. It agrees with the value (7/2)R predicted by equipartition at high temperatures (where R is the gas constant), but decreases to (5/2)R and then (3/2)R at lower temperatures, as the vibrational and rotational modes of motion are

In classical statistical mechanics, the equipartition theorem is a general formula that relates the temperature of a system with its average energies. The equipartition theorem is also known as the law of equipartition, equipartition of energy, or simply equipartition. The original idea of equipartition was that, in thermal equilibrium, energy is shared equally among all of its various forms; for example, the average kinetic energy per degree of freedom in the translational motion of a molecule should equal that of its rotational motions.
随便看

　

英汉网英语在线翻译词典收录了3779314条英语词汇在线翻译词条，基本涵盖了全部常用英语词汇的中英文双语翻译及用法，是英语学习的有利工具。

　

Copyright © 2004-2024 encnc.com All Rights Reserved
更新时间：2025/6/18 0:36:39