The rate equations for a continuous four level laser are solved in this letter, taking into account the finite lower level lifetime and the crystal field splitting of the laser levels.

在考虑了有限的下能级寿命和激光能级与晶格场的相互作用的基础上，对四能级激光的速率方程组进行了求解。

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Both the Kondo resonance and the spin-splitting of the single electron levels can be controlled by internal magnetization of the electrodes, which can be used to generate a spin-valve effect.

而近藤共振和单电子能级的自旋劈裂都可以通过电极的内部磁化强度来控制，可以用来产生自旋阀效应。

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Scientists say it formed when high sea levels flooded the middle of North America, splitting the continent in two for millions of years during the late Cretaceous period.

VOA: special.2010.10.05