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土壤中铬的形态及其转化 被引量:68
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作者 陈英旭 何增耀 吴建平 《环境科学》 CAS CSSCI CSCD 北大核心 1994年第3期53-56,共4页
通过土壤中不同结合态铬的逐级提取方法的研究,提出了以1mol/LNH4Ac、2mol/LHCl和5%H2O2-2mol/LHCl提取的铬分别为交换态铬、沉淀态铬和有机结合态铬。自然土壤中铬主要以沉淀态铬和残渣态铬形式... 通过土壤中不同结合态铬的逐级提取方法的研究,提出了以1mol/LNH4Ac、2mol/LHCl和5%H2O2-2mol/LHCl提取的铬分别为交换态铬、沉淀态铬和有机结合态铬。自然土壤中铬主要以沉淀态铬和残渣态铬形式存在。还原条件下,土壤中铬有向有机结合态铬转化的趋势。降低土壤pH,水溶态和代换态铬含量增加,沉淀态和残渣态铬含量降低,添加Cr(Ⅲ)能使土壤本身pH值下降,添加Cr(Ⅵ)使土壤pH值有所上升。 展开更多
关键词 土壤 逐级提取 形态转化
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有机质对冻融黑土重金属Zn赋存形态的影响 被引量:24
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作者 高文文 刘景双 王洋 《中国生态农业学报》 CAS CSCD 北大核心 2010年第1期147-151,共5页
冻融作用对不同有机质含量的土壤重金属Zn赋存形态转化产生显著影响,以24h为1个冻融周期,对150mg(Zn)·kg-1的黑土冻融8次,结果表明,随着有机质含量的增加,未经冻融土壤的交换态和铁锰氧化物结合态Zn含量逐渐降低,有机结合态Zn含量... 冻融作用对不同有机质含量的土壤重金属Zn赋存形态转化产生显著影响,以24h为1个冻融周期,对150mg(Zn)·kg-1的黑土冻融8次,结果表明,随着有机质含量的增加,未经冻融土壤的交换态和铁锰氧化物结合态Zn含量逐渐降低,有机结合态Zn含量逐渐增加,残渣态Zn含量变化不显著。冻融作用可促进交换态和铁锰氧化物结合态Zn含量降低,促进有机结合态和残渣态Zn含量增加。随着土壤有机质含量的增加,冻融作用使重金属Zn生物有效态含量降低。通过有机质含量与各形态Zn含量拟合,在未冻融和冻融条件下,各形态Zn含量与有机质含量之间呈二次多项式的函数关系,相关系数r2在0.664和0.995之间。 展开更多
关键词 重金属ZN 形态转化 冻融交替 有机质 黑土
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Exact solutions for nonlinear partial fractional differential equations 被引量:22
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作者 Khaled A.Gepreel Saleh Omran 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第11期32-38,共7页
′In this article, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved (G′/G)-expansion func... ′In this article, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved (G′/G)-expansion function method to calculate the exact solutions to the time- and space-fractional derivative foam drainage equation and the time- and space-fractional derivative nonlinear KdV equation. This method is efficient and powerful for solving wide classes of nonlinear evolution fractional order equations. 展开更多
关键词 fractional calculus complex transformation modified Riemann-Liouville derivative im- proved (G′/G)-expansion function method
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(G′/G)-Expansion Method for Solving Fractional Partial Differential Equations in the Theory of Mathematical Physics 被引量:16
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作者 郑滨 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第11期623-630,共8页
In this paper, the (G′/G)-expansion method is extended to solve fractional partial differential equations in the sense of modified Riemann-Liouville derivative. Based on a nonlinear fractional complex transformation,... In this paper, the (G′/G)-expansion method is extended to solve fractional partial differential equations in the sense of modified Riemann-Liouville derivative. Based on a nonlinear fractional complex transformation, a certain fractional partial differential equation can be turned into another ordinary differential equation of integer order. For illustrating the validity of this method, we apply it to the space-time fractional generalized Hirota-Satsuma coupled KdV equations and the time-fractional fifth-order Sawada-Kotera equation. As a result, some new exact solutions for them are successfully established. 展开更多
关键词 (G'/G)-expansion method fractional partial differential equations exact solutions fractionalcomplex transformation
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Traveling wave solutions to some nonlinear fractional partial differential equations through the rational(G'/G)-expansion method 被引量:7
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作者 Tarikul Islam M.Ali Akbar Abul Kalam Azad 《Journal of Ocean Engineering and Science》 SCIE 2018年第1期76-81,共6页
In this article,the analytical solutions to the space-time fractional foam drainage equation and the space-time fractional symmetric regu-larized long wave(SRLW)equation are successfully examined by the recently estab... In this article,the analytical solutions to the space-time fractional foam drainage equation and the space-time fractional symmetric regu-larized long wave(SRLW)equation are successfully examined by the recently established rational(G/G)-expansion method.The suggested equations are reduced into the nonlinear ordinary differential equations with the aid of the fractional complex transform.Consequently,the theories of the ordinary differential equations are implemented effectively.Three types closed form traveling wave solutions,such as hyper-bolic function,trigonometric function and rational,are constructed by using the suggested method in the sense of conformable fractional derivative.The obtained solutions might be significant to analyze the depth and spacing of parallel subsurface drain and small-amplitude long wave on the surface of the water in a channel.It is observed that the performance of the rational(G/G)-expansion method is reliable and will be used to establish new general closed form solutions for any other NPDEs of fractional order. 展开更多
关键词 Nonlinear space-time fractional equations Nonlinear fractional complex transformation Conformable fractional derivative Exact solutions
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博斯腾湖西岸湖滨绿洲土壤含盐量高光谱估算 被引量:7
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作者 赵慧 李新国 +2 位作者 靳万贵 麦麦提吐尔逊·艾则孜 牛芳鹏 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2020年第4期56-63,共8页
以博斯腾湖西岸湖滨绿洲土壤盐分及其对应的高光谱数据为研究对象,对原始光谱反射率(R)进行均方根(R)、对数(lg R)、倒数(1/R)、对数倒数(1/lg R)变换,引入分数阶微分对变换的光谱反射率进行0~2内的微分预处理,通过显著性检验优选特征波... 以博斯腾湖西岸湖滨绿洲土壤盐分及其对应的高光谱数据为研究对象,对原始光谱反射率(R)进行均方根(R)、对数(lg R)、倒数(1/R)、对数倒数(1/lg R)变换,引入分数阶微分对变换的光谱反射率进行0~2内的微分预处理,通过显著性检验优选特征波段,并利用特征波段进行偏最小二乘回归的建模和验证。结果表明:1)通过显著性检验较多的特征波段是:1/R为691个波段,比通过原始波段多226个波段;且随着阶数的增加,在各阶数中通过显著性检验的波段数量呈先增加后减少的趋势;通过数量较多的特征波段是1/R的0.4阶和0.6阶,分别为145、150;2)原始光谱反射率的相关性极大值绝对值是:2阶为0.53,其他4种数学变换的相关性极大值绝对值比R高0.11~0.16,特征波段主要集中在600~1000 nm和2020~2330 nm;3)在原始光谱反射率及其变换值的各分数阶微分利用偏最小二乘回归建模中,1/lgR的0.2阶建立的模型为最佳模型,RC^2=0.78,RMSEC=1.56,RV^2=0.63,RMSEV=1.44。 展开更多
关键词 分数阶微分 土壤含盐量 光谱变换 偏最小二乘回归 高光谱估算
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An Approach to Differential Geometry of Fractional Order via Modified Riemann-Liouville Derivative 被引量:1
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作者 Guy JUMARIE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2012年第9期1741-1768,共28页
In order to cope with some difficulties due to the fact that the derivative of a constant is not zero with the commonly accepted Riemann-Liouville definition of fractional derivative, one (Jumarie) has proposed rece... In order to cope with some difficulties due to the fact that the derivative of a constant is not zero with the commonly accepted Riemann-Liouville definition of fractional derivative, one (Jumarie) has proposed recently an alternative referred to as (local) modified Riemann-Liouville definition, which directly, provides a Taylor's series of fractional order for non differentiable functions. We examine here in which way this calculus can be used as a framework for a differential geometry of fractional or- der. One will examine successively implicit function, manifold, length of curves, radius of curvature, Christoffel coefficients, velocity, acceleration. One outlines the application of this framework to La- grange optimization in mechanics, and one concludes with some considerations on a possible fractional extension of the pseudo-geodesic of thespecial relativity and of the Lorentz transformation. 展开更多
关键词 fractional calculus modified Riemann-Liouville derivative fractional Taylor's series fractional manifold fractional geodesic fractional mechanics Lorentz transformation
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On limit fractional Volterra hierarchies
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作者 Lixiang Zhang Chuanzhong Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第1期7-16,共10页
For the limit fractional Volterra(LFV)hierarchy,we construct the n-fold Darboux transformation and the soliton solutions.Furthermore,we extend the LFV hierarchy to the noncommutative LFV(NCLFV)hierarchy,and construct ... For the limit fractional Volterra(LFV)hierarchy,we construct the n-fold Darboux transformation and the soliton solutions.Furthermore,we extend the LFV hierarchy to the noncommutative LFV(NCLFV)hierarchy,and construct the Darboux transformation expressed by quasi determinant of the noncommutative version.Meanwhile,we establish the relationship between new and old solutions of the NCLFV hierarchy.Finally,the quasi determinant solutions of the NCLFV hierarchy are obtained. 展开更多
关键词 limit fractional Volterra hierarchy noncommutative limit fractional Volterra hierarchy Darboux transformation soliton solution quasi determinant solution
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A New Approach for the Exact Solutions of Nonlinear Equations of Fractional Order via Modified Simple Equation Method 被引量:1
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作者 Muhammad Younis 《Applied Mathematics》 2014年第13期1927-1932,共6页
In this article, the modified simple equation method has been extended to celebrate the exact solutions of nonlinear partial time-space differential equations of fractional order. Firstly, the fractional complex trans... In this article, the modified simple equation method has been extended to celebrate the exact solutions of nonlinear partial time-space differential equations of fractional order. Firstly, the fractional complex transformation has been implemented to convert nonlinear partial fractional differential equations into nonlinear ordinary differential equations. Afterwards, modified simple equation method has been implemented, to find the exact solutions of these equations, in the sense of modified Riemann-Liouville derivative. For applications, the exact solutions of time-space fractional derivative Burgers’ equation and time-space fractional derivative foam drainage equation have been discussed. Moreover, it can also be concluded that the proposed method is easy, direct and concise as compared to other existing methods. 展开更多
关键词 Exact Solutions Complex transformation MODIFIED SIMPLE EQUATION METHOD Nonlinear Equations of fractional Order fractional Calculus Theory
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高阶非线性薛定谔方程的精确解研究 被引量:3
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作者 朱加民 《激光与红外》 CAS CSCD 北大核心 2006年第5期389-391,共3页
文章基于分数变换原理,研究了用于描述飞秒光脉冲传输的高阶非线性薛定谔方程,得到了它的各种包络型Jacobian椭圆函数双周期解和新型亮孤波解。分析结果表明:这种亮孤子的存在依赖于正三阶色散效应。
关键词 高阶非线性薛定谔方程 分数变换 孤波解
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Transportation inequalities for stochastic delay evolution equations driven by fractional Brownian motion 被引量:2
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作者 Zhi LI Jiaowan LUO 《Frontiers of Mathematics in China》 SCIE CSCD 2015年第2期303-321,共19页
We discuss stochastic functional partial differential equations and neutral partial differential equations of retarded type driven by fractional Brownian motion with Hurst parameter H 〉 1/2. Using the Girsanov transf... We discuss stochastic functional partial differential equations and neutral partial differential equations of retarded type driven by fractional Brownian motion with Hurst parameter H 〉 1/2. Using the Girsanov transformation argument, we establish the quadratic transportation inequalities for the law of the mild solution of those equations driven by fractional Brownian motion under the L2 metric and the uniform metric. 展开更多
关键词 Transportation inequality Girsanov transformation delay stochastic partial differential equation (SPDE) fractional Brownian motion (fBm)
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Exact Solutions for Fractional Differential-Difference Equations by an Extended Riccati Sub-ODE Method 被引量:2
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作者 冯青华 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第5期521-527,共7页
In this paper, an extended Riccati sub-ODE method is proposed to establish new exact solutions for fractional differential-difference equations in the sense of modified Riemann-Liouville derivative. By a fractional co... In this paper, an extended Riccati sub-ODE method is proposed to establish new exact solutions for fractional differential-difference equations in the sense of modified Riemann-Liouville derivative. By a fractional complex transformation, a given fractional differential-difference equation can be turned into another differential-difference equation of integer order. The validity of the method is illustrated by applying it to solve the fractional Hybrid lattice equation and the fractional relativistic Toda lattice system. As a result, some new exact solutions including hyperbolic function solutions, trigonometric function solutions and rational solutions are established. 展开更多
关键词 fractional differential-difference equations exact solutions Riccati sub-ODE method fractional complex transformation
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Exact Solution of Fractional Diffusion Model with Source Term used in Study of Concentration of Fission Product in Uranium Dioxide Particle 被引量:2
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作者 房超 曹建主 孙立风 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期863-867,共5页
The exact solution of fractional diffusion model with a location-independent source term used in the study of the concentration of fission product in spherical uranium dioxide (U02) particle is built. The adsorption... The exact solution of fractional diffusion model with a location-independent source term used in the study of the concentration of fission product in spherical uranium dioxide (U02) particle is built. The adsorption effect of the fission product on the surface of the U02 particle and the delayed decay effect are also considered. The solution is given in terms of Mittag-Leffler function with finite Hankel integral transformation and Laplace transformation. At last, the reduced forms of the solution under some special physical conditions, which is used in nuclear engineering, are obtained and corresponding remarks are given to provide significant exact results to the concentration analysis of nuclear fission products in nuclear reactor. 展开更多
关键词 fractional diffusion Fick's law source term finite Hankel transformation Laplace transformation
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Dynamic analysis of a new chaotic system with fractional order and its generalized projective synchronization 被引量:1
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作者 牛玉军 王兴元 +1 位作者 年福忠 王明军 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第12期97-104,共8页
Based on the stability theory of the fractional order system, the dynamic behaviours of a new fractional order system are investigated theoretically. The lowest order we found to have chaos in the new three-dimensiona... Based on the stability theory of the fractional order system, the dynamic behaviours of a new fractional order system are investigated theoretically. The lowest order we found to have chaos in the new three-dimensional system is 2.46, and the period routes to chaos in the new fractional order system are also found. The effectiveness of our analysis results is further verified by numerical simulations and positive largest Lyapunov exponent. Furthermore, a nonlinear feedback controller is designed to achieve the generalized projective synchronization of the fractional order chaotic system, and its validity is proved by Laplace transformation theory. 展开更多
关键词 dynamic analysis fractional order generalized projective synchronization Laplace transformation
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Peng's maximum principle for a stochastic control problem driven by a fractional and a standard Brownian motion 被引量:2
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作者 BUCKDAHN Rainer JING Shuai 《Science China Mathematics》 SCIE 2014年第10期2025-2042,共18页
We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another ... We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another one,driven only by the standard Brownian motion with coefficients depending on both the fractional Brownian motion and the standard Brownian motion.We derive a maximum principle and the associated stochastic variational inequality,which both are generalizations of the classical case. 展开更多
关键词 fractional Brownian motion stochastic control system backward stochastic differential equation variational inequality maximum principle Girsanov transformation Galtchouk-Kunita-Watanabe decomposition
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Modified Projective Synchronization of Fractional-order Chaotic Systems with Different Dimensions 被引量:2
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作者 Xi ZHANG Ran-chao WU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2020年第2期527-538,共12页
In this paper,the modified projective synchronization between two fractional-order chaotic systems with different dimensions is investigated.The added-order scheme and the reduced-order scheme are proposed,respectivel... In this paper,the modified projective synchronization between two fractional-order chaotic systems with different dimensions is investigated.The added-order scheme and the reduced-order scheme are proposed,respectively.Based on the Laplace transformation and feedback control theory,controllers are designed such that two chaotic systems with different dimensions could be synchronized asymptotically under the presented schemes.Corresponding numerical simulations are given to show the effectiveness of the proposed schemes. 展开更多
关键词 Modified PROJECTIVE SYNCHRONIZATION fractional-ORDER CHAOTIC systems LAPLACE transformation
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分数阶时滞系统的稳定性 被引量:2
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作者 方园 《阜阳师范学院学报(自然科学版)》 2012年第3期11-13,共3页
文章讨论了分数阶线性系统的稳定性问题,其中一部分状态含有时滞。借助Laplace变换,引入时滞系统的特征方程,最后,利用特征方程的根全部具有负实部则系统稳定的性质对系统稳定性进行了分析。
关键词 分数阶 时滞 LAPLACE变换 稳定
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含指数函数和指数积分函数的积分 被引量:2
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作者 金元松 《电子学报》 EI CAS CSCD 北大核心 1992年第6期77-80,共4页
本文对电磁场问题的理论计算中常遇到的含有指数函数和指数积分函数的积分,得出了解析表达式。
关键词 指数积分函数 电磁场 指数函数
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Generalized Canonical Transformations for Fractional Birkhoffian Systems 被引量:1
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作者 ZHANG Yi 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第4期499-506,共8页
This paper presents fractional generalized canonical transformations for fractional Birkhoffian systems within Caputo derivatives.Firstly,based on fractional Pfaff-Birkhoff principle within Caputo derivatives,fraction... This paper presents fractional generalized canonical transformations for fractional Birkhoffian systems within Caputo derivatives.Firstly,based on fractional Pfaff-Birkhoff principle within Caputo derivatives,fractional Birkhoff’s equations are derived and the basic identity of constructing generalized canonical transformations is proposed.Secondly,according to the fact that the generating functions contain new and old variables,four kinds of generating functions of the fractional Birkhoffian system are proposed,and four basic forms of fractional generalized canonical transformations are deduced.Then,fractional canonical transformations for fractional Hamiltonian system are given.Some interesting examples are finally listed. 展开更多
关键词 fractional Birkhoffian system generalized canonical transformation fractional Pfaff-Birkhoff principle generating function
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On a Boundary Value Problem for a Polynomial Pencil of the Sturm-Liouville Equation with Spectral Parameter in Boundary Conditions
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作者 A. Adiloglu Nabiev 《Applied Mathematics》 2016年第18期2418-2423,共7页
The boundary value problem with a spectral parameter in the boundary conditions for a polynomial pencil of the Sturm-Liouville operator is investigated. Using the properties of the transformation operators for such op... The boundary value problem with a spectral parameter in the boundary conditions for a polynomial pencil of the Sturm-Liouville operator is investigated. Using the properties of the transformation operators for such operators, the asymptotic formulas for eigenvalues of the boundary value problem are obtained. 展开更多
关键词 Sturm-Liouville Equation Boundary Value Problem transformation Operator Spectral Theory of Differential Operators Asymptotic Formulas fractional Derivative EIGENVALUE EIGENFUNCTION Polynomial Pencil
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