“relaxation time”的概念、定义、翻译、参考文献-科学参考

relaxation time

Astronomy

The time expected for the orbit of a star in a cluster or galaxy to be significantly changed through gravitational perturbation by other stars. For a cluster of N stars this is about 0.1N times the time a typical star takes to cross the cluster (the crossing time). Globular clusters are far older than their relaxation times, and hence are said to be relaxed. For the Galaxy, by contrast, the relaxation time is longer than the age of the Universe.

Geology and Earth Sciences

1. The time taken by a disturbed system to reach equilibrium, or the time taken for the magnitude of some parameter to decrease to about 37% of its initial value. For example, the temperature-dependent relaxation time (τ‎) of a dielectric is related to the relaxation frequency (f_r) such that τ‎ = 1/(2π‎f_r). Physically, it is the time taken for an ionic defect to move within a crystal lattice under the influence of an applied alternating electromagnetic field.
2. In geomorphology, the time taken for a system to become adjusted to a sustained change in the nature and/or intensity of external processes. Such an adjustment normally involves a change in the shape of the land-form or landscape constituting the system. Relaxation times vary. The width of a river channel may adjust in response to an increase in discharge in, perhaps, 10 years, while a glaciated mountain range may require 10⁵–10⁶ years to lose the imprint of ice.

Geography

The time taken by a geomorphological system to adjust to a sustained change in the nature/intensity of an external process. For the Yellow River, Wu et al. (2008) Geomorph. 100, 3–4 find a mean relaxation time of about five to six years for channel adjustment.

单词	relaxation time
释义	relaxation time Astronomy The time expected for the orbit of a star in a cluster or galaxy to be significantly changed through gravitational perturbation by other stars. For a cluster of N stars this is about 0.1N times the time a typical star takes to cross the cluster (the crossing time). Globular clusters are far older than their relaxation times, and hence are said to be relaxed. For the Galaxy, by contrast, the relaxation time is longer than the age of the Universe. Geology and Earth Sciences 1. The time taken by a disturbed system to reach equilibrium, or the time taken for the magnitude of some parameter to decrease to about 37% of its initial value. For example, the temperature-dependent relaxation time (τ‎) of a dielectric is related to the relaxation frequency (f_r) such that τ‎ = 1/(2π‎f_r). Physically, it is the time taken for an ionic defect to move within a crystal lattice under the influence of an applied alternating electromagnetic field. 2. In geomorphology, the time taken for a system to become adjusted to a sustained change in the nature and/or intensity of external processes. Such an adjustment normally involves a change in the shape of the land-form or landscape constituting the system. Relaxation times vary. The width of a river channel may adjust in response to an increase in discharge in, perhaps, 10 years, while a glaciated mountain range may require 10⁵–10⁶ years to lose the imprint of ice. Geography The time taken by a geomorphological system to adjust to a sustained change in the nature/intensity of an external process. For the Yellow River, Wu et al. (2008) Geomorph. 100, 3–4 find a mean relaxation time of about five to six years for channel adjustment.
随便看	Abelard’s thesis Abelian group abelian group abelian group(classification theorem) Abelianization Abel, John Jacob Abell Catalogue Abell cluster Abell radius Abel, Niels Henrik Abel, Niels Henrik (1802–29) Abel Prize Abel, Sir Frederick Augustus Abelson, Philip Hauge Abel summation Abel’s Limit Theorem Abel’s partial summation formula Abel’s test ABEND Aberdeen, George Hamilton Gordon, 4th Earl of (1784–1860) aberration aberration, constant of aberration of starlight aberration, optical ab esse ad posse valet consequentia