chronicle
发表于 2025-3-26 22:19:44
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冰雹
发表于 2025-3-27 04:23:42
Cortical and Periosteal Lesions,d to emission or absorption of radiation of a frequency that fulfills Bohr’s energy-frequency relation. In an absorption process, a photon is absorbed. In an emission process, a photon is emitted. Einstein found that the emission of a photon is possible by two different processes, spontaneous and st
真繁荣
发表于 2025-3-27 05:49:38
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nutrients
发表于 2025-3-27 09:48:04
A. Bhuyan,H. Messer,P. M. Schultheiss? Which are the sizes and the costs of lasers? Why is it necessary to have different types of lasers in the same frequency range? We will also mention some specific lasers and we will discuss the concept of the book.
obstinate
发表于 2025-3-27 13:42:55
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Ccu106
发表于 2025-3-27 19:39:20
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subacute
发表于 2025-3-27 23:16:31
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厨房里面
发表于 2025-3-28 04:12:25
Cortical and Periosteal Lesions,. In an emission process, a photon is emitted. Einstein found that the emission of a photon is possible by two different processes, spontaneous and stimulated emission, and that the coefficients describing the three processes—absorption, stimulated and spontaneous emission—are related to each other (Einstein relations).
骄傲
发表于 2025-3-28 10:13:17
Laser Principleresults in an increase of the energy density of the radiation. The active medium in a laser experiences feedback from radiation stored in a laser resonator. A portion of radiation coupled out of the resonator represents the useful radiation.
灌输
发表于 2025-3-28 13:12:42
Basis of the Theory of the Laser: The Einstein Coefficients. In an emission process, a photon is emitted. Einstein found that the emission of a photon is possible by two different processes, spontaneous and stimulated emission, and that the coefficients describing the three processes—absorption, stimulated and spontaneous emission—are related to each other (Einstein relations).