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利用整层模式大气统计求解GRAPES-3DVAR动力平衡约束的数值试验 被引量:5
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作者 王瑞春 龚建东 +1 位作者 张林 薛谌彬 《热带气象学报》 CSCD 北大核心 2014年第4期633-642,共10页
针对采用单层模式大气中统计求解风压场平衡关系的不足,采用改进方案,在表达动力平衡约束时考虑不同层次上变量之间的相关,利用整层模式大气中的旋转风场统计求解每一层上质量场的平衡部分。改进方案通过类岭回归方法减少多重共线性以... 针对采用单层模式大气中统计求解风压场平衡关系的不足,采用改进方案,在表达动力平衡约束时考虑不同层次上变量之间的相关,利用整层模式大气中的旋转风场统计求解每一层上质量场的平衡部分。改进方案通过类岭回归方法减少多重共线性以及小尺度噪音对统计求解的不利影响,提高了统计结果的稳健程度。数值试验结果表明,相对于原有方案,采用整层模式大气统计求解的方案能更好地保证质量场在垂直方向分析的合理性,减少数字滤波初始化对分析增量的调整,提高位温的分析效果。在冬、夏两个代表月同化预报循环的对比试验中,改进方案对温度场的预报效果有明显提高,对风压场预报也有一定程度的正效果。 展开更多
关键词 三维变分同化 动力平衡约束 统计求解 GRAPES 数值试验
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New Approach for Solving Master Equations in Quantum Optics and Quantum Statistics by Virtue of Thermo-Entangled State Representation 被引量:11
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作者 FAN Hong-Yi HU Li-Yun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期729-742,共14页
By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation (η|, which can arrange master equations of density operators p(t) in quant... By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation (η|, which can arrange master equations of density operators p(t) in quantum statistics as state-vector evolution equations due to the elegant properties of (η|. In this way many master equations (respectively describing damping oscillator, laser, phase sensitive, and phase diffusion processes with different initial density operators) can be concisely solved. Specially, for a damping process characteristic of the decay constant k we find that the matrix element of p(t) at time t in 〈η| representation is proportional to that of the initial po in the decayed entangled state (ηe^-kt| representation, accompanying with a Gaussian damping factor. Thus we have a new insight about the nature of the dissipative process. We also set up the so-called thermo-entangled state representation of density operators, ρ = f(d^2η/π)(η|ρ〉D(η), which is different from all the previous known representations. 展开更多
关键词 master equation fictitious mode thermo-entangled state representation damping oscillator and laser phase sensitive and phase diffusion processes
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