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有理函数变换法求扩展(3+1)维Jimbo-Miwa方程丰富的精确解(英文) 被引量:2
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作者 哈金婷 李欣越 张辉群 《上海师范大学学报(自然科学版)》 2019年第3期261-271,共11页
利用扩展的有理函数变换法对两个扩展的(3+1)维Jimbo-Miwa方程进行了研究,得到了丰富的精确解,特别是共振孤波解,复合解及三角函数、双曲函数和指数函数结合形式的解。除此之外,对所得解的结构作了详细的图像展示和性质分析。
关键词 (3+1)维Jimbo-Miwa方程 有理函数变换 复合解
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有理函数变换法求解两类扩展的(3 + 1)维Jimbo-Miwa方程
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作者 哈金婷 关雪 张辉群 《应用数学进展》 2018年第10期1247-1255,共9页
在本文中,我们引入有理函数变换法对两类扩展的(3 + 1)维Jimbo-Miwa方程进行了研究。通过这种方法并借助于Maple软件得到了它们新的行波精确解,而且如果我们选择不同的常微分方程,还可以得到不同类的行波解,补充了以往文献的研究成果。
关键词 (3+1)维Jimbo-Miwa方程 有理函数变换 新的行波精确解
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磁性材料复磁导率的宽带测量及模型 被引量:3
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作者 梁涛 谢彦召 《强激光与粒子束》 EI CAS CSCD 北大核心 2016年第1期83-88,共6页
分析了线圈杂散参数对高频下复磁导率测量的影响,指出绕组电阻、寄生电容及漏感会导致传统复磁导率测量方法在高频下误差增大。在此基础上提出了使用单匝全包结构进行复磁导率宽带测量的方法,该方法适用于400 MHz以下频率的复磁导率测... 分析了线圈杂散参数对高频下复磁导率测量的影响,指出绕组电阻、寄生电容及漏感会导致传统复磁导率测量方法在高频下误差增大。在此基础上提出了使用单匝全包结构进行复磁导率宽带测量的方法,该方法适用于400 MHz以下频率的复磁导率测量。介绍了复磁导率的常见模型,并分别使用Levy法及有理函数迭代逼近法(IRFA)进行模型参数提取,分析了两种算法的优缺点及应用范围。应用推荐复磁导率测量方法对三种磁性材料进行了复磁导率的测量和建模,结果表明,使用推荐的复磁导率测量方法及数据提取算法,可以较好地实现对磁性材料的小信号建模。 展开更多
关键词 磁性材料 复磁导率 有理函数迭代逼近 小信号模型 杂散参数
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IKONOS-2卫星影像纠正及精度分析 被引量:7
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作者 熊轶群 《北京测绘》 2004年第1期5-7,共3页
随着遥感技术、计算机技术的发展,遥感已经从高端的科学研究步入实际应用的各个领域。特别是美国SpaceImage公司于1999年9月26日发射了世界上首颗高分辨率商业卫星IKONOS-2,这标志着高分辨率的遥感时代已经来临。其1米分辨率的卫星影像... 随着遥感技术、计算机技术的发展,遥感已经从高端的科学研究步入实际应用的各个领域。特别是美国SpaceImage公司于1999年9月26日发射了世界上首颗高分辨率商业卫星IKONOS-2,这标志着高分辨率的遥感时代已经来临。其1米分辨率的卫星影像使对地观测达到了一个新阶段--既能满足“数字地球”的需要,也能代替航空摄影并满足工程勘察的需要。本文在研究遥感图像的一般多项式法、有理函数法等多种纠正方法的基础上,对实验区的IKONOS卫星影像进行纠正,通过比较其纠正结果,提出了在使用有理多项式系数(RPC)基础上,通过有理函数法对IKONOS影像进行纠正的方法。 展开更多
关键词 卫星影像纠正 精度分析 一般多项式 有理函数法
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Further Extended Jacobi Elliptic Function Rational Expansion Method and New Families of Jacobi Elliptic Function Solutions to (2+1)-Dimensional Dispersive Long Wave Equation
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作者 ZHANG Yuan-Yuan WANG Qi ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第2期199-206,共8页
In this paper, a further extended Jacobi elliptic function rationM expansion method is proposed for constructing new forms of exact solutions to nonlinear partial differential equations by making a more general transf... In this paper, a further extended Jacobi elliptic function rationM expansion method is proposed for constructing new forms of exact solutions to nonlinear partial differential equations by making a more general transformation. For illustration, we apply the method to (2+1)-dimensionM dispersive long wave equation and successfully obtain many new doubly periodic solutions. When the modulus m→1, these sohitions degenerate as soliton solutions. The method can be also applied to other nonlinear partial differential equations. 展开更多
关键词 doubly periodic solution soliton solution (2+1)-dimensional dispersive long wave equation
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New Families of Rational Form Solitary Wave Solutions to (2+1)-Dimensional Broer-Kaup-Kupershmidt System*
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作者 WANGQi CHENYong +1 位作者 LIBiao ZHANGHong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期769-774,共6页
Taking the (2+1)-dimensional Broer-Kaup-Kupershmidt system as a simple example, some families of rational form solitary wave solutions, triangular periodic wave solutions, and rational wave solutions are constructed b... Taking the (2+1)-dimensional Broer-Kaup-Kupershmidt system as a simple example, some families of rational form solitary wave solutions, triangular periodic wave solutions, and rational wave solutions are constructed by using the Riccati equation rational expansion method presented by us. The method can also be applied to solve more nonlinear partial differential equation or equations. 展开更多
关键词 Riccati equation rational expansion method (2+1) -dimensional Broer-Kaup-Kupershmidt system symbolic computation rational form solitary wave solutions
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Extended Jacobi Elliptic Function Rational Expansion Method and Its Application to (2+1)-Dimensional Stochastic Dispersive Long Wave System
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作者 SONG Li-Na ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第6期969-974,共6页
In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evo... In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evolution equations. To illustrate the effectiveness of our method, we take the (2+ 1)-dimensional stochastic dispersive long wave system as an example. We not only have obtained some known solutions, but also have constructed some new rational formal stochastic Jacobi elliptic function solutions. 展开更多
关键词 stochastic evolution equations (2+ 1)-dimensional stochastic dispersive long wave system rational formal stochastic Jacobi elliptic function solutions
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New Extended Jacobi Elliptic Function Rational Expansion Method and Its Application
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作者 ZHENG Ying ZHANG Yuan-Yuan ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第1X期5-9,共5页
In this paper, an extended Jacobi elliptic function rational expansion method is proposed for constructing new forms of exact Jacobi elliptic function solutions to nonlinear partial differential equations by means of ... In this paper, an extended Jacobi elliptic function rational expansion method is proposed for constructing new forms of exact Jacobi elliptic function solutions to nonlinear partial differential equations by means of making a more general transformation. For illustration, we apply the method to the (2+1)-dimensional dispersive long wave equation and successfully obtain many new doubly periodic solutions, which degenerate as soliton solutions when the modulus m approximates 1. The method can also be applied to other nonlinear partial differential equations. 展开更多
关键词 extended Jacobi elliptic function rational expansion method rational formal Jacobi elliptic function solution (2+1)-dimensional dispersive long wave equation
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移动车辆非定常气动力时域模拟及分析 被引量:4
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作者 严乃杰 苏永华 +3 位作者 郭辉 班新林 李永乐 向活跃 《中国公路学报》 EI CAS CSCD 北大核心 2021年第4期119-127,共9页
为了在时域中考虑复数导纳函数,精细化模拟作用在移动列车上的非定常气动力,提出列车复数导纳函数时频变换方法,并建立同时考虑顺风向、横风向和竖向脉动风的移动列车非定常气动力数学模型。首先,推导出相对于移动列车的瞬时风速,并将... 为了在时域中考虑复数导纳函数,精细化模拟作用在移动列车上的非定常气动力,提出列车复数导纳函数时频变换方法,并建立同时考虑顺风向、横风向和竖向脉动风的移动列车非定常气动力数学模型。首先,推导出相对于移动列车的瞬时风速,并将瞬时风速代入到移动列车风荷载模型中,通过泰勒级数展开和忽略脉动风速、三角函数高阶项,将移动列车非定常气动力表示成关于顺风向、横风向和竖向脉动风的函数。然后,基于有理函数逼近法,将频域的复数导纳函数展开成有理函数项表示,再通过拉普拉斯逆变换实现导纳函数的时频变换,并将变换后的时域导纳函数代入推导的气动力模型中,精细化模拟移动列车非定常气动力。最后,通过与加权函数法对比,验证基于有理函数逼近法模拟移动列车非定常气动力方法的正确性,分析复数导纳函数相位、横风向和竖向脉动风对列车非定常气动力的影响。研究结果表明:有理函数逼近法可以成功实现列车复数导纳函数的时频变换,能够在非定常气动力时域模拟中有效考虑复数导纳函数的相位特性;导纳函数能够降低气动力的峰值,其相位可以使得非定常气动力时程产生"延迟";横风向和竖向脉动风对列车非定常气动力的贡献不容忽视,能够使得气动力峰值显著增大;在列车非定常气动力模拟中,应该综合考虑复数导纳函数以及横风向和竖向脉动风的影响。研究结果可为移动列车风荷载及风-车-桥耦合振动等相关研究提供参考。 展开更多
关键词 桥梁工程 非定常气动力 有理函数逼近 移动列车 导纳函数 时域模拟
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Determination of the limits for multivariate rational functions
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作者 XIAO ShuiJing ZENG GuangXing 《Science China Mathematics》 SCIE 2014年第2期397-416,共20页
The purpose of this paper is to solve the problem of determining the limits of multivariate rational functions.It is essential to decide whether or not limxˉ→0f g=0 for two non-zero polynomials f,g∈R[x1,...,xn]with... The purpose of this paper is to solve the problem of determining the limits of multivariate rational functions.It is essential to decide whether or not limxˉ→0f g=0 for two non-zero polynomials f,g∈R[x1,...,xn]with f(0,...,0)=g(0,...,0)=0.For two such polynomials f and g,we establish two necessary and sufcient conditions for the rational functionf g to have its limit 0 at the origin.Based on these theoretic results,we present an algorithm for deciding whether or not lim(x1,...,xn)→(0,...,0)f g=0,where f,g∈R[x1,...,xn]are two non-zero polynomials.The design of our algorithm involves two existing algorithms:one for computing the rational univariate representations of a complete chain of polynomials,another for catching strictly critical points in a real algebraic variety.The two algorithms are based on the well-known Wu’s method.With the aid of the computer algebraic system Maple,our algorithm has been made into a general program.In the final section of this paper,several examples are given to illustrate the efectiveness of our algorithm. 展开更多
关键词 rational function LIMIT infinitesimal element strictly critical point rational univariate represen-tation (RUR) Wu's method transfer principle
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