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少模液芯光子晶体光纤中飞秒脉冲的演化研究
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作者 于慧敏 文进 +4 位作者 王倩 武政委 张辉 张颖 潘雨 《红外》 CAS 2024年第4期13-24,共12页
本文旨在研究少模光纤中飞秒脉冲的传输与演化特性。提出了一种高非线性少模甲苯液芯光子晶体光纤(Toluene Liquid-Core Photonic Crystal Fiber,TLC-PCF)。泵浦波长处的非线性系数约为42 W^(-1)·km^(-1)。采用多模广义非线性薛定... 本文旨在研究少模光纤中飞秒脉冲的传输与演化特性。提出了一种高非线性少模甲苯液芯光子晶体光纤(Toluene Liquid-Core Photonic Crystal Fiber,TLC-PCF)。泵浦波长处的非线性系数约为42 W^(-1)·km^(-1)。采用多模广义非线性薛定谔方程(Multimode Generalized Nonlinear Schr9dinger Equation,MM-GNLSE)对飞秒脉冲的传输与演化进行了建模和求解。对比了不同峰值功率(1 kW、10 kW、50 kW)的能量转移特性。当中心波长为2000 nm、峰值功率为50 kW、脉宽为200 fs的高斯脉冲在30 cm长的TLC-PCF中传输时,得到1980~2500 nm的超连续谱输出,能量转移在0.02 m处首次到达平衡点。数值结果表明,当一个模式被激发时,其简并模式会发生能量转移,且四波混频(Four-Wave Mixing,FWM)负责TLC-PCF中模式间的能量转移。本文创新性地采用MM-GNLSE理论分析具有慢非线性的少模液芯光子晶体光纤中的模式耦合、超连续谱产生(Supercontinuum Generation,SCG)以及能量转移特性。 展开更多
关键词 光纤 脉冲传输 超连续谱产生 广义非线性薛定谔方程 甲苯
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模函数的Hlder连续性与次可乘性
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作者 马晓艳 裘松良 +1 位作者 钟根红 褚玉明 《高校应用数学学报(A辑)》 CSCD 北大核心 2012年第4期481-487,共7页
研究了模函数φK(a,r)的Hlder连续性及次可乘性,建立了φK(a,r)的几个精确不等式.
关键词 高斯超几何函数 广义模方程 函数
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模函数的Hlder连续性和次可乘性
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作者 马晓艳 《浙江理工大学学报(自然科学版)》 2012年第5期727-729,共3页
模函数φK(r)在几何函数论、模方程理论得到广泛研究,如拟共形映照理论中Hlder连续性和次可乘性,文章研究了广义Ramanujan模方程解φK(a,r)的Hlder连续性和次可乘性。当a=1/2时,φK(a,r)=φK(r)。
关键词 广义Ramanujan方程 函数 Hlder连续性 次可乘性
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New Agegraphic Dark Energy in Brans-Dicke Theory 被引量:1
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作者 LIU Xiang-Lai ZHANG Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第10期761-768,共8页
In this paper, we investigate the new agegraphic dark energy model in the framework of Brans-Dicke theory, which is a natural extension of the Einstein's general relativity. In this framework the form of the new ageg... In this paper, we investigate the new agegraphic dark energy model in the framework of Brans-Dicke theory, which is a natural extension of the Einstein's general relativity. In this framework the form of the new agegraphic dark energy density takes as pq = 3n^2Ф(t)η^-2, where η is the conformal age of the universe and Ф(t) is the Brans-Dicke scalar field representing the inverse of the time-variable Newton's constant. We derive the equation of state of the new agegraphic dark energy and the deceleration parameter of the universe in the Brans-Dicke theory. It is very interesting to find that in the Brans-Dicke theory the agegraphic dark energy realizes quintom-like behavior, i.e., its equation of state crosses the phantom divide ω= -1 during the evolution. We also compare the situation of the agegraphic dark energy model in the Brans-Dicke theory with that in the Einstein's theory. In addition, we discuss the new agegraphic dark energy model with interaction in the framework of the Brans-Dicke theory. 展开更多
关键词 agegraphic dark energy quantum gravity cosmic acceleration Brans--Dicke theory
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Reconstructing Quintom from WMAP 5-year Observations:Generalized Ghost Condensate
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作者 张敬飞 桂元星 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第8期380-388,共9页
In the 5-year WMAP data analysis, a new parametrization form for dark energy equation-of-state was used, and it has been shown that the equation-of-state, w(z), crosses the cosmological-constant boundary w = -1. Bas... In the 5-year WMAP data analysis, a new parametrization form for dark energy equation-of-state was used, and it has been shown that the equation-of-state, w(z), crosses the cosmological-constant boundary w = -1. Based on this observation, in this paper, we investigate the reconstruction of quintom dark energy model. As a single-real-sealarfield model of dark energy, the generalized ghost condensate model provides us with a successful mechanism for realizing the quintom-like behavior. Therefore, we reconstruct this scalar-field quintom dark energy model from the WMAP 5-year observational results. As a comparison, we also discuss the quintom reconstruction based on other specific dark energy ansatzs, such as the CPL parametrization and the holographic dark energy scenarios. 展开更多
关键词 dark energy quintom ghost condensate
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Hamiltonian Forms for a Hierarchy of Discrete Integrable Coupling Systems
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作者 XU Xi-Xiang YANG Hong-Xiang LU Rong-Wu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第12期1269-1275,共7页
A semi-direct sum of two Lie algebras of four-by-four matrices is presented,and a discrete four-by-fourmatrix spectral problem is introduced.A hierarchy of discrete integrable coupling systems is derived.The obtainedi... A semi-direct sum of two Lie algebras of four-by-four matrices is presented,and a discrete four-by-fourmatrix spectral problem is introduced.A hierarchy of discrete integrable coupling systems is derived.The obtainedintegrable coupling systems are all written in their Hamiltonian forms by the discrete variational identity.Finally,we prove that the lattice equations in the obtained integrable coupling systems are all Liouville integrable discreteHamiltonian systems. 展开更多
关键词 integrable lattice equation semi-direct sum of Lie algebra integrable coupling system discrete variational identity Hamiltonian form Liouville integrability
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Exact Generator and its High Order Expansions in Time-Convolutionless Generalized Master Equation:Applications to Spin-Boson Model and Exictation Energy Transfer
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作者 Yan-yingLiu Ya-mingYan +2 位作者 MengXu Kai Song QiangShi 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第4期575-583,616,共10页
The time-convolutionless (TCL) quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kern... The time-convolutionless (TCL) quantum master equation provides a powerful tool to simulate reduced dynanfics of a quantum system coupled to a bath. The key quantity ill the TCL master equation is the so-called kernel or generator, which describes eflhcts of the bath degrees of freedom. Since the exact TCL generators are usually hard to calculate analytically, most applications of the TCL generalized master equation have relied on approximate generators using second and fourth order perturbative expansions. By using the hierarchical equation of motion (HEOM) and extended HEOM methods, we present a new approach to calculating the exact TCL generator and its high order perturbative expansions. The new approach is applied to the spin-boson model with diflhrent sets of parameters, to investigate the convergence of the high order expansiolls of the TCL generator. We also discuss circumstances where the exact TCL generator becomes singular for the spin-boson model, and a model of excitation energy transfer in the Fenna-Matthews-Olson complex. 展开更多
关键词 Tirne-convolutionless generalized rnaster equation Spin-boson model Exactgenerator High order expansion
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A generalized sinusoidal model and its applications
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作者 库少平 《Journal of Chongqing University》 CAS 2009年第1期70-74,共5页
A physical model of sinusoidal function was established. It is generalized that the force is directly proportional to a power function of the distance in a classical spring-oscillator system. The differential equation... A physical model of sinusoidal function was established. It is generalized that the force is directly proportional to a power function of the distance in a classical spring-oscillator system. The differential equation of the generalized model was given. Simulations were conducted with different power values. The results show that the solution of the generalized equation is a periodic function. The expressions of the amplitude and the period(frequency) of the generalized equation were derived by the physical method. All the simulation results coincide with the calculation results of the derived expressions. A special function also was deduced and proven to be convergent in the theoretical analysis. The limit value of the special function also was derived. The generalized model can be used in solving a type of differential equation and to generate periodic waveforms. 展开更多
关键词 sinusoidal function sinusoidal model differential equation waveform generator
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A Model-calibration Approach to Using Complete Auxiliary Information from Stratified Sampling Survey Data
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作者 WU Chang-chun ZHANG Run-chu 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第2期309-316,共8页
In stratified survey sampling, sometimes we have complete auxiliary information. One of the fundamental questions is how to effectively use the complete auxiliary information at the estimation stage. In this paper, we... In stratified survey sampling, sometimes we have complete auxiliary information. One of the fundamental questions is how to effectively use the complete auxiliary information at the estimation stage. In this paper, we extend the model-calibration method to obtain estimators of the finite population mean by using complete auxiliary information from stratified sampling survey data. We show that the resulting estimators effectively use auxiliary information at the estimation stage and possess a number of attractive features such as asymptotically design-unbiased irrespective of the working model and approximately model-unbiased under the model. When a linear working-model is used, the resulting estimators reduce to the usual calibration estimator(or GREG). 展开更多
关键词 model-calibration pseudo empirical likelihood stratified sampling survey complete auxiliary information estimating equations generalized linear models superpopulation
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Generalized Maximum Fuzzy Entropy Methods with Applications on Wind Speed Data
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作者 Aladdin Shamilov Sevil Senturk Nihal Yilmaz 《Journal of Mathematics and System Science》 2016年第1期46-52,共7页
This study is connected with new Generalized Maximum Fuzzy Entropy Methods (GMax(F)EntM) in the form of MinMax(F)EntM and MaxMax(F)EntM belonging to us. These methods are based on primary maximizing Max(F)En... This study is connected with new Generalized Maximum Fuzzy Entropy Methods (GMax(F)EntM) in the form of MinMax(F)EntM and MaxMax(F)EntM belonging to us. These methods are based on primary maximizing Max(F)Ent measure for fixed moment vector function in order to obtain the special functional with maximum values of Max(F)Ent measure and secondary optimization of mentioned functional with respect to moment vector functions. Distributions, in other words sets of successive values of estimated membership function closest to (furthest from) the given membership function in the sense of Max(F)Ent measure, obtained by mentioned methods are defined as (MinMax(F)Ent)m which is closest to a given membership function and (MaxMax(F)Ent)m which is furthest from a given membership function. The aim of this study consists of applying MinMax(F)EntM and MaxMax(F)EntM on given wind speed data. Obtained results are realized by using MATLAB programme. The performances of distributions (MinMax(F)En0m and (MaxMax(F)Ent)m generated by using Generalized Maximum Fuzzy Entropy Methods are established by Chi-Square, Root Mean Square Error criterias and Max(F)Ent measure. 展开更多
关键词 Maximum fuzzy entropy measure Generalized maximum fuzzy entropy methods Moment vector functions Membership function.
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Investigating biological population model using exp-function method 被引量:1
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作者 Qazi Mahmood Ul Hassan Syed Tauseef Mohyud-Din 《International Journal of Biomathematics》 2016年第2期159-173,共15页
This paper is the spectator of the arrangement of an efficient transformation and exfunction technique to build up generalized exact solutions of the biological population model equation. Computational work and subseq... This paper is the spectator of the arrangement of an efficient transformation and exfunction technique to build up generalized exact solutions of the biological population model equation. Computational work and subsequent numerical results re-identify the effectiveness of proposed algorithm. It is pragmatic that recommended plan is greatly consistent and may be comprehensive to other nonlinear differential equations of fractional order. 展开更多
关键词 Biological population model fractional calculus exp-function method.
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Thermodynamic compatibility and mechanical analogue of the generalized Jeffreys and generalized Oldroyd-B fluids with fractional derivatives 被引量:3
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作者 YANG Pan ZHU KeQin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第4期737-742,共6页
The study of generalized Jeffreys and generalized Oldroyd-B fluids with fractional derivatives has made rapid progress as an example of applications of fractional calculus in theology. However, their thermodynamic com... The study of generalized Jeffreys and generalized Oldroyd-B fluids with fractional derivatives has made rapid progress as an example of applications of fractional calculus in theology. However, their thermodynamic compatibility and mechanical ana- logue have not yet been properly considered. In the present study, by discussing both these issues, we find that the two orders of fractional derivatives in the constitutive equation of the generalized Jeffreys fluid must be the same in order to ensure that the equation is physically correct. Based on this generalized Jeffreys fluid, a thermodynamically compatible generalized Oldryd-B fluid is also proposed by the convected coordinates approach. 展开更多
关键词 generalized Jeffreys fluid generalized Oldroyd-B fluid thermodynamic compatibility mechanical analogue
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From Dislocation Motion to an Additive Velocity Gradient Decomposition, and Some Simple Models of Dislocation Dynamics
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作者 Amit ACHARYA Xiaohan ZHANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第5期645-658,642,共14页
A mathematical theory of time-dependent dislocation mechanics of unrestricted geometric and material nonlinearity is reviewed. Within a "small deformation" setting, a suite of simplified and interesting mode... A mathematical theory of time-dependent dislocation mechanics of unrestricted geometric and material nonlinearity is reviewed. Within a "small deformation" setting, a suite of simplified and interesting models consisting of a nonlocal Ginzburg Landau equation, a nonlocal level set equation, and a nonlocal generalized Burgers equation is derived.In the finite deformation setting, it is shown that an additive decomposition of the total velocity gradient into elastic and plastic parts emerges naturally from a micromechanical starting point that involves no notion of plastic deformation but only the elastic distortion,material velocity, dislocation density and the dislocation velocity. Moreover, a plastic spin tensor emerges naturally as well. 展开更多
关键词 Dislocations PLASTICITY Continuum mechanics Finite deformation
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Ramanujan's cubic transformation and generalized modular equation
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作者 WANG MiaoKun CHU YuMing SONG YingQing 《Science China Mathematics》 SCIE CSCD 2015年第11期2387-2404,共18页
We study the quotient of hypergeometric functions in the theory of Ramanujan's generalized modular equation for a ∈ (0, 1/2], and find an infinite product for- mula for μ1/3(r) by use of the properties of μ*a... We study the quotient of hypergeometric functions in the theory of Ramanujan's generalized modular equation for a ∈ (0, 1/2], and find an infinite product for- mula for μ1/3(r) by use of the properties of μ*a(r) and Ramanujan's cubic transformation. Besides, a new cubic transformation formula of hypergeometric function is given, which complements the Ramanujan's cubic transformation. 展开更多
关键词 Gaussian hypergeometric function Ramanujan's cubic transformation generalized modular equa-tion infinite product modular function
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Anisotropic Inflationary Scenario Via Generalized Chaplygin Gas Model
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作者 Abdul Jawad Shamaila Rani 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第5期653-658,共6页
We investigate generalized chaplygin gas for warm inflationary scenario in the context of locally rotationally symmetric Bianchi type I universe model.We assume two different cases of dissipative coefficient,i.e.,cons... We investigate generalized chaplygin gas for warm inflationary scenario in the context of locally rotationally symmetric Bianchi type I universe model.We assume two different cases of dissipative coefficient,i.e.,constant as well as function of scalar field.We construct dynamical equations as well as a relationship between scalar and radiation energy densities under slow-roll approximation.We also derive slow-roll parameters,scalar and tensor power spectra,scalar spectral index,tensor to scalar ratio for analyzing inflationary background during high dissipative regime.We also use the WMAP7 data for the discussion of our parameters. 展开更多
关键词 anisotropic universe model inflation generalized chaplygin gas
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