classical diffusion 中文意思是什麼
classical diffusion
解釋
等離子經典擴散-
According to gaseous " molecular kinetic, the mass diffusion rate is within finite value. so theoretical conclusion of mass flux ' s producing and the essential relation of flux vs. force could be drawn. with the assumption that local density states in near equilibrium and the distribution is gradual changed, the classical first pick ' s law was modified considering mass relaxation time
根據氣體分子運動論對質量傳播速度為有限值情況下的質量流的產生及流與力之間的本構關系作了理論推導，在假定局域濃度處于近平衡態，其分佈為漸進的情況下得到了考慮質量鬆弛作用的經典fick第一定律的修正式。 -
As one of the several models to improve the drift - diffusion model, the hydrodynamic model plays an increasingly important role in simulating the behavior of the charge carrier in sub - micron semiconductor devices because it can exhibit velocity overshoot and ballistic effects for which are not accounted the classical drift - diffusion model
漂移擴散模型自上世紀五十年代初一出現，就得到了人們的廣泛關注。但隨著微電子技術的發展，它不能很好的解釋半導體中的有些現象，流體動力學模型就應運而生了。 -
In this thesis, a semi - classical model of the force on an atom is used to describe the motion of a two - level atom interacting with a standing wave laser field. the velocity dependent force and momentum diffusion are derived through optical bloch equations by using the matrix form of the continued fraction technique. by investigating the dynamic properties of atoms in laser field, we can control and manipulate the mechanical motion of an atom
本文利用半經典理論，從二能級原子在激光駐波場中所滿足的運動方程出發，推導出密度矩陣元所滿足的遞推關系，利用矩陣連分數方法求解出密度矩陣元，從而求出依賴于原子運動速度的光壓力與動量擴散系數，通過討論原子在激光場中的動力學行為，為原子在激光場中被囚禁、形成原子列陣以及可控制的量子態，從而為量子信息處理提供理論基礎。 -
A local theorem for ruin probability in the classical risk model perturbed by diffusion
帶隨機干擾經典風險模型破產概率的局部定理 -
This feature reflects the physical phenomenon of breaking of waves and development of shock waves. in the fields of fulid dynamics, ( 0. 2. 1 ) is an approximation of small visvosity phenomenon. if viscosity ( or the diffusion term, two derivatives ) are added to ( 0. 2. 1 ), it can be researched in the classical way which say that the solutions become very smooth immediately even for coarse inital data because of the diffusion of viscosity. a natural idea ( method of regularity ) is obtained as follows : solutions of the viscous convection - diffusion pr oblem approachs to the solutions of ( 0. 2. 1 ) when the viscosity goes to zeros. another method is numerical method such as difference methods, finite element method, spectrum method or finite volume method etc. numerical solutions which is constructed from the numerical scheme approximate to the solutions of the hyperbolic con - ervation laws ( 0. 2. 1 ) as the discretation parameter goes to zero. the aim of these two methods is to construct approximate solutions and then to conside the stability of approximate so - lutions ( i, e. the upper bound of approximate solutions in the suitable norms, especally for that independent of the approximate parameters ). using the compactness framework ( such as bv compactness, l1 compactness and compensated compactness etc ) and the fact that the truncation is small, the approximate function consquence approch to a function which is exactly the solutions of ( 0. 2. 1 ) in some sense of definiton
當考慮粘性后，即在數學上反映為（ 0 . 1 . 1 ）中多了擴散項（二階導數項） ，即使很粗糙的初始數據，解在瞬間內變的很光滑，這由於流體的粘性擴散引起，這種對流-擴散問題可用古典的微分方程來研究。自然的想法就是當粘性趨于零時，帶粘性的對流-擴散問題的解在某意義下趨于無粘性問題（ 0 . 1 . 1 ）的解，這就是正則化方法。另一辦法從離散（數值）角度上研究僅有對流項的守恆律（ 0 . 1 . 1 ） ，如構造它的差分格式，甚至更一般的有限體積格式，有限元及譜方法等，從這些格式構造近似解（常表現為分片多項式）來逼近原守恆律的解。
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