perturbation approximation 中文意思是什麼

perturbation approximation 解釋
微擾近似
  • perturbation : n. 1. 慌張，動搖；混亂。2. 狼狽，不安，焦慮。3. 引起不安[混亂]的事物；引起動搖的原因。4. 【天文學】攝動；【物理學】微擾。adj. -al
  • approximation : n. 1. 接近；近似。2. 【數學】近似值。3. 概算，略計。
  1. Its biquadratic finite element approximation is considered and under the appropriately graded meshes, quasi - optimal order error estimates in the - weighted h ^ 1 - norm, up to a logarithmic factor in the singular perturbation parameter, are proved

    然後，考慮此方程在分層網格剖分上的雙二次有限元逼近，在-加權h ^ 1 -模意義下得到了至多相差一個關于攝動參數對數因子的擬最優階收斂的誤差估計。
  2. Collisonal quantum interference ( cqi ) was observed in the intramolecular rotational energy transfer in the experiment of the static cell, and the integral interference angles were measured. to observe more precise information, the experiment in the molecular beam should be taken, from which the differential interference angle can be obtained precisely. in this paper, the theoretical model of cqi is described in an atom - diatom system in the condition of the molecular beam, based on the first - born approximation of time dependent perturbation theory, taking into accounts the anisotropic lennard - jones interaction potentials. the method of observing and measuring correctly the differential interference angle is presented. the changing tendencies of the differential interference angle with the impact parameter, velocity, and et al. are discussed

    分子內部轉動傳能的靜態池實驗觀察到了碰撞量子干涉效應（ cqi ） ，並且測得積分干涉角，為了獲得更加精確的分子內部轉動傳能的碰撞量子干涉效應信息，實驗就必須要採用分子束實驗進行.本文理論上採用各項異性相互作用勢，應用含時微擾理論的一級波恩近似，假想在分子束實驗的條件下，建立在原子-雙原子分子體系中碰撞量子干涉的理論模型.理論上推導出微分干涉角具體表達式，通過計算定性地討論了微分干涉角隨著碰撞參數、速率等的變化趨勢，同時初步探討了實驗的正確觀測途徑，得出了採用分子束進行實驗觀測的實驗方法，為進一步進行分子束實驗提供了理論基礎，對實驗的進行起到了一定的借鑒作用
  3. We must seek two main approximation methods of solution, the variation method and perturbation theory.

    我們必須尋求兩個主要的近似解法、變分法和微擾法。
  4. The equation including the nonlinear dispersion, i. e. the modified nonlinear schrodinger ( mnls ) equation, is a better model. in this thesis, we take mnls solitons as a model for femtosecond soltions. then based on the recently developed direct perturbation theory for perturbed mnls equation, we study the raman self - frequency shift of femtosecond solitons and its suppression by the means of frequency filters. for this purpose, first, we define the physical parameters of mnls solitons ; next, through the direct perturbation theory for perturbed mnls equation, under adiabatic approximation, we obtain the evolving parameters of mnls soliton on our questions and then choose the parameters of frequency filters based on it ; at last, we directly numerically simulated our questions by split - step fourier ( ssf ) method after improving the arithmetic of the differentiation of the nonlinear item for satisfying mnls equation

    本論文以mnls孤子作為光纖飛秒孤子的模型，通過新近建立的mnls孤子直接微擾理論，研究光纖中由拉曼效應引起的飛秒孤子在傳輸中的自頻移，以及通過頻率濾波對自頻移的抑制。為此，首先給出描述mnls孤子的各物理量，然後用mnls孤子直接微擾理論，解析地得到這些問題絕熱近似下的孤子參數演化，並由此選擇頻率濾波的參數，最後用分步傅里葉方法，在對非線性項微商的演算法做出了適合於mnls孤子的改善後，對拉曼效應及頻率濾波進行了直接數值模擬，其中頻率濾波參數用微擾理論確定。
  5. Secondly, the effectiveness and limitation of the classical perturbation, such as the method of multiple scales and the poincare - lindstedt method, are discussed in detail through a duffing oscillator with delayed velocity feedback. it is shown that the two perturbation methods are effective only in solving the approximate solution of the first two orders. an ambiguity or paradox will be encountered when they are used to seeking for the third or higher order approximation of solution

    其次，以一具有時滯速度反饋的duffing系統為例，研究了經典攝動法如多尺度法， poincar - lindstedt法等在求解時滯微分方程級數解時的適用性和局限性問題，指出利用這些方法只能有效求得系統的前兩階近似解，而在求系統的三次以上近似解時會出現矛盾或二義性。
  6. A successive approximation procedure for complex eigenvalue perturbation problem

    廣義復特徵值攝動問題的逐步逼近法
  7. The quadratic programming perturbation approximation method for the linear programming problem

    求解線性規劃問題的二次規劃攝動逼近法
  8. The results of numerical experiments, using the four - dimensional variational data assimilation system of the nonhydrostatic mesoscale model mm5, show that : the tangent linear model and adjoint model conducted by keeping the " on - off " switches the same as the basic state, can provide a good approximation of the first - order information to the nlm perturbation and a good descent direction for the minimization procedure ; switching on and off at every other time step in the kuo cumulus parameterization scheme do n ' t impact the convergence rate of cost function ; the existence of the switches do n ' t impact improvement to the mm5 model rainfall prediction because that not only specific humidity, but also wind, temperature and pressure are assimilated into the model

    非靜力中尺度數值模式mm5的四維變分資料同化系統進行的數值試驗結果表明： 「開關」變量保持與基態一致，所構造的切向線性模式能夠提供關于非線性模式擾動的一階近似，伴隨模式所計算的梯度值能夠為最小化過程提供較好的下降方向；郭氏降水參數化方案中對流每隔一個積分步的交替發生並不影響目標函數最小化的收斂速度； 「開關」變量的存在也不影響將風、溫度、氣壓和比濕結合起來同化對mm5降水預報準確性的提高。
  9. First, we concisely recall the formation and development of bose - einstein condensa - tion ' s theory and it ' s experimentation. secondly, we briefly intro - duce some properties of weakly interactive bose gases, and derive the nonlinear gross - pitaevskii equation that is the condensate macroscopic wave function ' s equation. thirdly, we give a exam - pie, an approximation analytical solution of the gross - pitaevskii equation in a spherical symmetric harmonic trap is derived by a perturbation theory approach, this solution is consistent with that numerically obtained

    全文共分為四章：第一章首先簡要的介紹和回顧了玻色-愛因斯坦凝聚理論的產生和發展，以及其實驗研究的過程，然後著重介紹了弱相互作用的玻色氣體的一些性質，並推導出了凝聚體宏觀波函數滿足非線性的gp方程，還以球對稱的諧振子勢為例，用標準的微擾方法求出了定態的gp方程近似解，發現其與已知的數值結果符合得很好。
  10. A perturbation method by tight - binding approximation which provide the relation of phase constant and angular spectrum of fields of in - waveguide is presented. the strip width of phase constant can be given. on the other hand, the group delay - time due to the k dispersion in single - mode transmission can also be estimated

    提出一種利用緊束縛近似的微擾法計算陣列波導的相位常數與輸入光角譜的關系，由此算出相位常數的帶寬，並利用衍射方法估算單模傳輸中k色散引起的群延時。
  11. The second aspect : from qgp kinetic equations with collision integrals, by using the relaxation time approximation, we calculate the distribution functions to the second order correction. we obtain the distribution functions for quarks ( and anti - quarks ) and gluons under perturbation of the fluctuation of the color field. then in the high - temperature - low - density area, we discuss the characteristics of the distribution functions, and use t hem to get the net baryon density and the energy density

    第二，從有碰撞項的qgp動力論方程出發，忽略自旋，在色漲落擾動下，利用弛豫時間近似，得到夸克和膠子分佈函數的二級修正，通過數值分析重點討論了高溫低密情況下qgp中成分粒子分佈函數的特性，並且由分佈函數得到凈重子數密度和能量密度。
  12. Schrodinger equation, bound states, hydrogen atoms, wave packets and uncertainty relations, wkb approximation, principle of quantum mechanis, perturbation theory, variational method, spin and angular momentum, scattering theory

    薛丁格方程、束縛態、氫原子、波包及測不準原理、 wkb近似、量子力學的原理、微擾論、變方法、自旋與角動量、散射論。
  13. In this paper, we first investigate the impurity effect ( ba2 + ) on the dielectric and phase transition properties in srtio3 within the framework of the transverse - field ising model ( tim ). then a possible coupling mechanism between the magnetism and dielectric properties in eutio3 is discussed and the magnetic influence on the frequency of the soft - phonon mode is investigated via the heisenberg model, soft - mode theory under the mean field approximation, the second quantization theory and the perturbation theory. and we proceed further investigation on eu1 - xbaxtio3 of

    我們發現baxeul _ xtio3 （ o 『 x 『 0 . 2 ）的介電常數和由內察的偏置場導致的電極化除了隨雜質濃度產生相應的變化，同時在磁和介電性質的藕合作用影響下在低溫下偏離通常的量子順電體行為，在尼爾溫度附近出現異常，且磁場通過對最近鄰自旋關聯的作用來影響介電常數和電極化。
  14. The first section introduces the background, significance and the relative development of the dissertation. then the roughness of rough surface and the basic theories of the scattering of electromagnetic waves from rough surfaces are discussed, and the kirchhoff approximation and small perturbation method are presidented in detail

    然後介紹了描述隨機粗糙面的有關統計特性參量，給出了處理粗糙面散射問題的不同方法，指明了各自的適用條件，並對經典粗糙面電磁散射的kirchhoff標量近似法和微擾法做了詳細闡述。
  15. It is said that the stochastic perturbation method basically could not fulfil the requirement of dynamical random response problems. however, so far in the dissipative systems, this is not the case. thirdly, the unified approach is combined with the orthogonal polynomial approximation

    3 ）將統一解法，與正交多項式逼近方法結合起來，指出文獻中流傳的採用正態pdf來描述隨機結構參數的缺陷，並先後提出了拱形概率密度與更具有一般性的? pdf模型，並分別與chebyshev多項式逼近、 gegenbauer多項式逼近相配合，構成了一套具有廣泛適應性的解法。
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