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The Center and the Fine Focus for a Class of Quartic Polynomial Poincare Equations 被引量:2
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作者 TIANDe-sheng ZENGXian-wu YUChang-chun LIPei-luan 《Wuhan University Journal of Natural Sciences》 CAS 2004年第6期867-870,共4页
We study a class of quartic polynomial Poincare equations by applying a recurrence formula of focal value. We give the necessary and sufficient conditions for the origin to be a center, and prove that the order of fin... We study a class of quartic polynomial Poincare equations by applying a recurrence formula of focal value. We give the necessary and sufficient conditions for the origin to be a center, and prove that the order of fine focus at the origin for this class of equations is at most 6. Key words quartic polynomial Poincare equation - center - fine focus - order CLC number O 175. 12 Foundation item: Supported by the National Natural Science Foundation of China (19531070)Biography: TIAN De-sheng (1966-), male, Ph. D candidate, research direction: qualitative theory of differential equation. 展开更多
关键词 quartic polynomial Poincare equation CENTER fine focus order
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FIXED POINTS AND STABILITY FOR QUARTIC MAPPINGS IN β-NORMED LEFT BANACH MODULES ON BANACH ALGEBRAS 被引量:2
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作者 H.Azadi KENARY A.R.ZOHDI M.Eshaghi GORDJI 《Acta Mathematica Scientia》 SCIE CSCD 2013年第4期1113-1118,共6页
The goal of the present paper is to investigate some new HUR-stability results by applying the alternative fixed point of generalized quartic functional equationin β-Banach modules on Banach algebras. The concept of ... The goal of the present paper is to investigate some new HUR-stability results by applying the alternative fixed point of generalized quartic functional equationin β-Banach modules on Banach algebras. The concept of Ulam-Hyers-Rassias stability (briefly, HUR-stability) originated from Th. M. Rassias stability theorem that appeared in his paper: On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc. 72 (1978), 297-300. 展开更多
关键词 generalized Hyers-Ulam stability quartic functional equation Banach mod-ule unital Banach algebra generalized metric space fixed point method
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MODIFIABLE QUARTIC AND QUINTIC CURVES WITH SHAPE-PARAMETERS 被引量:2
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作者 邬弘毅 朱功勤 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2001年第1期9-19,共11页
This paper presents a method for creating modificable quartic and quintic curves with shape parameters. The curves can achieve C 2 even C 3 continuity and unify both interpolation and approximation to the control poin... This paper presents a method for creating modificable quartic and quintic curves with shape parameters. The curves can achieve C 2 even C 3 continuity and unify both interpolation and approximation to the control points without solving a system of equations or inserting additional control points. They have the local properties like the cubic B spline. Besides, the quintic curve would be able globally to tend the control polygon. 展开更多
关键词 modifiable quartic and quintic curves shape parameters C 2 or C 3 continuity interpolation and approximation.
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Pull-in instability analyses for NEMS actuators with quartic shape approximation 被引量:1
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作者 Junsheng DUAN Zongxue LI Jinyuan LIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第3期303-314,共12页
The pull-in instability of a cantilever nano-actuator model incorporating the effects of the surface, the fringing field, and the Casimir attraction force is investigated. A new quartic polynomial is proposed as the s... The pull-in instability of a cantilever nano-actuator model incorporating the effects of the surface, the fringing field, and the Casimir attraction force is investigated. A new quartic polynomial is proposed as the shape function of the beam during the deflection, satisfying all of the four boundary values. The Gaussian quadrature rule is used to treat the involved integrations, and the design parameters are preserved in the evaluated formulas. The analytic expressions are derived for the tip deflection and pull-in parameters of the cantilever beam. The micro-electromechanical system (MEMS) cantilever actuators and freestanding nano-actuators are considered as two special cases. It is proved that the proposed method is convenient for the analyses of the effects of the surface, the Casimir force, and the fringing field on the pull-in parameters. 展开更多
关键词 micro-electromechanical system (MEMS) nano-electromechanical system(NEMS) Casimir force pull-in instability quartic shape function
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Ground-state vortex structures of a rotating binary dipolar Bose–Einstein condensate confined in harmonic plus quartic potential
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作者 陈光平 乔昌兵 +3 位作者 郭慧 王林雪 王雅君 谭仁兵 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期251-256,共6页
We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions ... We consider a binary dipolar Bose–Einstein condensate confined in a rotating harmonic plus quartic potential trap.The ground-state vortex structures are numerically obtained as a function of the contact interactions and the dipole–dipole interaction in both slow and rapid rotation cases. The results show that the vortex configurations depend strongly on the strength of the contact interactions, the relative strength between dipolar and contact interactions, as well as on the orientation of the dipoles. A variety of exotic ground-state vortex structures, such as pentagonal and hexagon vortex lattice,square vortex lattice with a central vortex, annular vortex lines, and straight vortex lines, are observed by turning such controllable parameters. Our results deepen the understanding of effects of dipole–dipole interaction on the topological defects. 展开更多
关键词 Bose–Einstein condensate dipolar–dipolar interaction HARMONIC PLUS quartic POTENTIAL trap vortex structure
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Quartic coupling and its effect on wetting behaviors in nematic liquid crystals
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作者 曾明颖 Holger Merlitz 吴晨旭 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第2期325-329,共5页
Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates,a quartic coupling is included in constructing the surface energy for a liquid crystal cell.The phase diagram an... Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates,a quartic coupling is included in constructing the surface energy for a liquid crystal cell.The phase diagram and the wetting behaviors of the liquid crystal cell,bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate are discussed by taking the quartic coupling into account.The nematic order increases at the surface while it decreases in the bulk as a result of the introduction of quartic substrate-liquid crystal coupling,indicating that the groove anchoring makes the liquid crystal molecules align more orderly near the substrate than away from it.This causes a different wetting behavior:complete wetting. 展开更多
关键词 quartic coupling surface anchoring energy phase transition wetting behavior
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Bioconvection Mangnetohydrodynamic Tangent Hyperbolic Nanofluid Flow with Quartic Chemical Reaction Past a Paraboloid Surface
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作者 S.M.Atif W.A.Khan +1 位作者 Muhammad Abbas Umair Rashid 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第1期205-220,共16页
In this numerical study,the effect of quartic autocatalysis type of chemical reaction,buoyancy force and thermal radiation phenomenon and magnetic effect on tangent hyperbolic nanofluid past an upper horizontal surfac... In this numerical study,the effect of quartic autocatalysis type of chemical reaction,buoyancy force and thermal radiation phenomenon and magnetic effect on tangent hyperbolic nanofluid past an upper horizontal surface of a paraboloid has been studied.By considering the Buongiorno model approach,a diffusion of unequal coefficients in the presence of gyrotactic microorganism is discussed.Implementation of microorganism’s idea is used to stabilize the nanoparticles through bioconvection.The modeled PDEs of the problems are converted into nonlinear ODEs with the assistant of the similarity transformations.To tackle nonlinear ODEs,MATLAB package bvp4c is used.In addition,a hallmark of the Matlab code with the reported results in the literature is achieved by benchmarking.The variations in motion,concentration,temperature,and motile density due to sundry parameters have been analyzed in-depth via graphs.Our analysis shows that the density profile of motile of microorganism is hiked with an increment in the bioconvection Rayleigh number but decreases for higher thermal Grashof number. 展开更多
关键词 quartic autocatalysis tangent hyperbolic nanofluid brownian motion paraboloid of revolution MHD flow thermophoresis
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Jacobi Quartic曲线上GLV/GLS标量乘算法
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作者 翁江 姬伟峰 +3 位作者 吴玄 李映岐 张林锋 孟浩 《电子学报》 EI CAS CSCD 北大核心 2021年第9期1783-1789,共7页
目前GLV/GLS (Gallant,Lambert,Vanstone/Galbraith, Lin, Scott)标量乘算法的研究主要集中在Weierstrass曲线上,尝试寻找和构造更多或者更高次数的可有效计算的自同态.本文主要研究了Jacobi Quartic曲线上GLV/GLS标量乘算法.首先利用... 目前GLV/GLS (Gallant,Lambert,Vanstone/Galbraith, Lin, Scott)标量乘算法的研究主要集中在Weierstrass曲线上,尝试寻找和构造更多或者更高次数的可有效计算的自同态.本文主要研究了Jacobi Quartic曲线上GLV/GLS标量乘算法.首先利用曲线之间的双有理等价,给出了该类曲线在素域上可有效计算自同态的具体构造,得到2维GLV方法 .然后考虑椭圆曲线的二次扭曲线,利用曲线之间双有理等价和Frobenius映射,给出了该类曲线在二次扩域上可有效计算自同态的具体构造,得到2维GLS方法 .将上述GLV和GLS方法结合起来,同时利用曲线在二次扩域上的两个不同的自同态,得到4维GLV方法 .最后针对j不变量为0或1728两类特殊形式的椭圆曲线,利用更高次的扭曲线,得到4维GLV方法 .实验结果表明:对于Jacobi Quartic曲线,2维GLV方法和4维GLV方法比5-NAF方法分别提速37.2%和109.4%以上.同时,在三种不同的实现方式下,Jacobi Quartic曲线上标量乘效率都优于Weierstrass曲线. 展开更多
关键词 椭圆曲线 Jacobi quartic曲线 标量乘 GLV方法 GLS方法 可有效计算的自同态
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A note on Pythagorean hodograph quartic spiral
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作者 ZHENG Zhi-hao WANG Guo-zhao 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2018年第2期234-252,共19页
By using the geometric constraints on the control polygon of a Pythagorean hodo- graph (PH) quartic curve, we propose a sufficient condition for this curve to have monotone curvature and provide the detailed proof. ... By using the geometric constraints on the control polygon of a Pythagorean hodo- graph (PH) quartic curve, we propose a sufficient condition for this curve to have monotone curvature and provide the detailed proof. Based on the results, we discuss the construction of spiral PH quartic curves between two given points and formulate the transition curve of a G2 contact between two circles with one circle inside another circle. In particular, we deduce an attainable range of the distance between the centers of the two circles and summarize the algorithm for implementation. Compared with the construction of a PH quintic curve, the complexity of the solution of the equation for obtaining the transition curves is reduced. 展开更多
关键词 Pythagorean hodograph quartic curve SPIRAL CURVATURE transition curve
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ERROR BOUNDS IN PERIODIC QUARTIC SPLINE INTERPOLATION
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作者 Riaz A.Usmani 《Analysis in Theory and Applications》 1996年第3期1-9,共9页
In this paper we develop periodic quartic spline interpolation theory which,in general,gives better fus to continuous functions than does the existing quintic spline interpolation theory.The main theorem of the paper ... In this paper we develop periodic quartic spline interpolation theory which,in general,gives better fus to continuous functions than does the existing quintic spline interpolation theory.The main theorem of the paper is to establish that r=0,1,2,3.Also,the nanperiodic cases cannot be constructed empoly-ing the methodology of this paper because that will involve several other end conditions entirely different than(1,10). 展开更多
关键词 ERROR BOUNDS IN PERIODIC quartic SPLINE INTERPOLATION 二凡 SPI
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An Unconditionally Monotone <i>C</i><sup>2</sup>Quartic Spline Method with Nonoscillation Derivatives
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作者 Jin Yao Karl E. Nelson 《Advances in Pure Mathematics》 2018年第1期25-40,共16页
A one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C2 ... A one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C2 and unconditionally monotone. A set of control points is employed to constrain the curvature of the interpolation function and to eliminate possible nonphysical oscillations in the slope space. An extension of this method in two-dimensions is also discussed. 展开更多
关键词 MONOTONE Interpolation quartic NON-OSCILLATION Derivative Interface Reconstruction Slope Space HERMIT Spline
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Green’s Function for the Quartic Oscillator
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作者 Robert L. Anderson 《Applied Mathematics》 2016年第14期1571-1579,共9页
In this paper, a quantum mechanical Green’s function  for the quartic oscillator is presented. This result is built upon two previous papers: first [1], detailing the linearization of the quartic oscillator (qo)... In this paper, a quantum mechanical Green’s function  for the quartic oscillator is presented. This result is built upon two previous papers: first [1], detailing the linearization of the quartic oscillator (qo) to the harmonic oscillator (ho);second [2], the integration of the classical action function for the quartic oscillator. Here an equivalent form for the quartic oscillator action function  in terms of harmonic oscillator variables is derived in order to facilitate the derivation of the quartic oscillator Green’s Function, namely in fixing its amplitude. 展开更多
关键词 Nonrelativistic quartic QUANTUM MECHANICS Green’s OSCILLATOR
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New Approach to Approximate Circular Arc by Quartic Bezier Curve
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作者 Azhar Ahmad Rohaidah Masri Jamaluddin M. Ali 《Open Journal of Applied Sciences》 2012年第4期132-737,共606页
This paper presents a result of approximation an arc circles by using a quartic Bezier curve. Based on the barycentric coordinates of two and three combination of control points, the interior control points are determ... This paper presents a result of approximation an arc circles by using a quartic Bezier curve. Based on the barycentric coordinates of two and three combination of control points, the interior control points are determined by forcing the curvature at median point as similar as the given curvature at end points. Hausdorff distance is used to investigate the order of accuracy compare to the actual arc circles through central angle of . We found that the optimal approximation order is eight which is somewhat similar to preceding methods in the literatures. 展开更多
关键词 ARC circle barycentric COORDINATE HAUSDORFF distance quartic BEZIER
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Direct Fisher Inference of the Quartic Oscillator’s Eigenvalues
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作者 S. P. Flego Angelo Plastino A. R. Plastino 《Journal of Modern Physics》 2011年第11期1390-1396,共7页
It is well known that a suggestive connection links Schr?dinger’s equation (SE) and the information-optimizing principle based on Fisher’s information measure (FIM). It has been shown that this entails the existence... It is well known that a suggestive connection links Schr?dinger’s equation (SE) and the information-optimizing principle based on Fisher’s information measure (FIM). It has been shown that this entails the existence of a Legendre transform structure underlying the SE. Such a structure leads to a first order partial differential equation (PDE) for the SE’s eigenvalues from which a complete solution for them can be obtained. We test this theory with regards to anharmonic oscillators (AHO). AHO pose a long-standing problem and received intense attention motivated by problems in quantum field theory and molecular physics. By appeal to the Cramer Rao bound we are able to Fisher-infer the energy eigenvalues without explicitly solving Schr?dinger’s equation. Remarkably enough, and in contrast with standard variational approaches, our present procedure does not involve free fitting parameters. 展开更多
关键词 INFORMATION Theory Fisher’s INFORMATION Measure LEGENDRE Transform quartic ANHARMONIC Oscillator
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基于粒子群优化的改进四次S型加减速控制算法
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作者 张青山 吴正平 《科学技术与工程》 北大核心 2023年第8期3338-3344,共7页
针对基于传统三次S型加减速算法在数控机床起止端加加速度不连续,存在柔性冲击,以及传统四次S型加减速算法模型繁复,时间复杂度高的问题,设计加加速度曲线在加速区间、减速区间的开始和结束阶段连续不断变化,提高了速度曲线变化的平滑性... 针对基于传统三次S型加减速算法在数控机床起止端加加速度不连续,存在柔性冲击,以及传统四次S型加减速算法模型繁复,时间复杂度高的问题,设计加加速度曲线在加速区间、减速区间的开始和结束阶段连续不断变化,提高了速度曲线变化的平滑性,减低了工件加工运行时间。同时,提出一种基于粒子群算法的速度规划方法,根据加减速控制模型构建其适应度函数,继而得到加减速规划所需的所有参数。最后通过MATLAB对所提算法进行仿真实验。结果表明:所提算法能有效降低系统的柔性冲击,并提高加工精度和运行效率。 展开更多
关键词 数控系统 加减速算法 四次S形曲线 速度规划 粒子群算法(PSO)
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一类时间可逆四次系统的等时中心 被引量:1
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作者 桑波 刘文健 朱思铭 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 2011年第4期59-63,共5页
当中心邻域的闭轨周期为常数时,该中心称为等时中心.解决等时中心问题的主要难点在于周期系数代数簇的分解和横截交换系统的计算.对于一类含有三次非线性项的时间可逆四次系统,给出了周期系数的递推算法,在此基础上,利用吴方法得到了系... 当中心邻域的闭轨周期为常数时,该中心称为等时中心.解决等时中心问题的主要难点在于周期系数代数簇的分解和横截交换系统的计算.对于一类含有三次非线性项的时间可逆四次系统,给出了周期系数的递推算法,在此基础上,利用吴方法得到了系统具有等时中心的充要条件. 展开更多
关键词 时间可逆系统 四次系统 等时中心 等时性
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一类四次多项式系统原点的极限环分支 被引量:1
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作者 卢景苹 《广西科学》 CAS 2013年第2期85-87,共3页
给出一类四次多项式系统原点的前8个奇点量,由奇点量导出焦点量,得到该系统原点成为8阶细焦点的条件,证明该系统从原点可以分支出8个极限环.
关键词 四次多项式系统 奇点量 焦点量 极限环
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具有三次曲线解的二次系统的极限环的存在性 被引量:2
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作者 沈伯骞 刘德明 《辽宁师范大学学报(自然科学版)》 CAS 1990年第2期1-7,共7页
本文证明了具有三次曲线解y^2=ax^3+bx^2+cx+d的二次系统是可以存在极限环的。证明了当且仅当此三次曲线解的图象具有一个孤立点的情形时,才有可能存在极限环,并得出了此系统存在极限环的条件。
关键词 三次曲线解 二次系统 极限环
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第一临界情形下的四次系统的局部拓扑结构
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作者 李学敏 张筱玮 《山东师范大学学报(自然科学版)》 CAS 1997年第3期241-244,共4页
讨论了第一临界情形下的平面四次系统高次奇点的局部拓扑结构。
关键词 第一临界情形 四次系统 拓扑结构 稳定性
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基于四次位移曲线加减速方法的CNC系统的设计 被引量:2
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作者 赵文龙 李立斌 《机床与液压》 北大核心 2010年第6期18-20,共3页
介绍基于四次位移曲线加减速方法的CNC系统的硬件结构和软件结构,并进行了实验验证,结果表明该系统在加减速控制等方面都取得良好的效果。与传统的数控系统相比,性能得到很大的改善。
关键词 加减速控制方法 四次位移曲线加减速方法 CNC系统
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