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1.
本文的主要目的是把Melnikov方法推广到一般的系统x=f(t,x,ε),利用指数二分性和Liapunov-Schmidt方法,我们对一般系统构造了一个Melnikov型函数。  相似文献   

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A class of nonlinear elliptic problems driven by p(x)-Laplacian with a nonsmooth locally Lipschitz potential is considered.By applying the version of the nonsmooth three-critical-point theorem,the existence of three solutions to the problems is proved.  相似文献   

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为探讨Mandelbrot集(简称M集)的外部结构,Philip曾提出了“区域分解”和“角度分解”方法。本文推广了这两种方法,提出了等势线和色彩调配法,并利用这四种方法构造了复映射z←z^w c(w=α iβ)的广义M集的外部结构图。研究表明广义M集的外部结构具有分形特征,其断裂的原因是主幅角选取的不连续性。  相似文献   

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Chaos is closely associated with homoclinic orbits in deterministic nonlinear dynamics. In this paper, analytic expressions of homoclinic orbits for some (2+1)- dimensional nonlinear Schrodinger-like equations are constructed based on Hirota's bilinear method, including long wave-short wave resonance interaction equation, generalization of the Zakharov equation, Mel'nikov equation, and g-Schrodinger equation are constructed based on Hirota's bilinear method.  相似文献   

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在研究非线性振动问题时,有时会出现奇数维微分方程组。对于这类系统,采用传统的KBM方法在建立标准方程时就遇到了困难。本文提出了求解奇数维非线性动力学系统的推广KBM平均法。通过具体的算例,说明于得到原系统的平均方程进而,求得渐近解或对系统分岔行为研究。  相似文献   

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Fluidization data acquired, processed and printed out inone integral instrument: pressure drop versus gas velocity fluctuating height versus gas velocity minimum fluidization velocity quality of fluidization expressed in terms of bed collapsing curves: rate of bubble escape rate of particulate sedimentation in dense phase rate of consolidation of packed solids printout of dimensionless subsidence time  相似文献   

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本文列举了诸多工程领域中的液体共振运动现象,详细探讨了船舱中伴有剧烈流动的晃荡问题.描述了基于理论分析的非线性多模态方法,该方法便于波动稳定性分区、多分支解和物理稳定性的研究.强调了方形舱、垂向圆柱舱以及球形舱内伴有旋转和混沌(不规则波动)的三维流动的重要性.晃荡引起的砰击涉及到各种各样的内流条件,这些条件随液体深度与舱体长度之比而变化.针对棱柱状LNG舱,讨论了许多与流体力学和热力学参数、影响砰击载荷效应的水弹性以及模型实验缩尺比的物理现象.  相似文献   

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叶轮机内部流场的修正Taylor—Galerkin(MDTGFE)有限元法   总被引:2,自引:0,他引:2  
朱刚  胡庆康 《力学季刊》1994,15(4):58-63
首先改进了TGFE的基本假设考虑前后时间步之间的非线性效应,对流函数-涡量方程进行有限元离散,得到了修正Taylor-Galerkin算法的有限元离散公式。采用这种方法,我们计算了后台阶绕流流动。另外,还用本方法的思想计算了叶轮机内部准三元流动。  相似文献   

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混沌振动压实动力学的仿真研究—(I)混沌识别   总被引:1,自引:0,他引:1  
本文提出了四自由度混沌振动压路机“机架-振动轮-土”系统的力学模型;建立了其数学模型;对数学模型进行了数值仿真;根据振动轮的运动,利用混沌识别的定性方法(相轨图、功率谱图和Poincare图)与定量方法(最大Lyapunov指数),对系统的混沌特征进行了识别。结果表明:系统的运动是混沌的。  相似文献   

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评价膜-基体系的综合性能的重要指标是其失效的临界载荷。膜-基体系的失效不仅发生在界面,也有可能发生在镀层或底材之中,或许还有可能发生混合失效,因此,在测试膜-基低系失效的临界载荷方面,即使是已经在国内外得到广泛应用的划痕法也有其弱点,为了使膜-基体系的失效临界载荷的测试尽可能地接近于实际使用工况,更能切近实际地反映膜-基体系的综合承载能力,提出了一种擦膜试验法,并且研制了CM-1型多功能擦膜摩擦试  相似文献   

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本文将计算Normal-form的常用方法-矩阵法编写成Mathematica程序包,借助于Mathematica的符号推导功能,将矩阵法的全部计算步骤模块化,使程序包具有通用性,适用于计算二维系统的任意阶normal-form、三维系数的2、3阶normal-form、高维系统的二阶normal-form。  相似文献   

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为了精确计算可倾瓦推力轴承的静特性,本文建立了推力轴承静特性的计算模型,推导了推力轴承动力润滑的基本Reynolds方程,考虑了润滑油温粘效应、素流的影响、瓦块的温度变形及压力弹性变形。本文还以广州蓄能水电厂一期工程四号机组的推力轴承为例,计算了几种不同初始参数条件下的计算结果,以期对机组推力轴承的特性有一个较全面的认识和了解。  相似文献   

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Shallow water waves and a host of long wave phenomena are commonly investigated by various models of nonlinear evolution equations. Examples include the Korteweg–de Vries, the Camassa–Holm, and the Whitham–Broer–Kaup (WBK) equations. Here a generalized WBK system is studied via the multi-linear variable separation approach. A special class of wave profiles with discontinuous derivatives (“peakons”) is developed. Peakons of various features, e.g. periodic, pulsating or fractal, are investigated and interactions of such entities are studied. The project supported by the National Natural Science Foundation of China (10475055, 10547124 and 90503006), and the Hong Kong Research Grant Council Contract HKU 7123/05E.  相似文献   

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Ni—W(D)合金电刷镀层的滑动磨损特性研究   总被引:5,自引:2,他引:5  
研究了 Ni- W( D)合金刷镀层在不同载荷下的滑动磨损特性 ,用扫描电子显微镜观察试样磨损表面形貌 ,用铁谱仪和流体光谱仪分别分析磨屑的尺寸和成分 .结果表明 :在载荷 1 0 0~ 2 0 0 N下 ,Ni- W( D)合金镀层磨损表面主要呈现轻微擦伤迹象 ,刷镀层表现出优良的抗磨能力 ;在 30 0 N载荷下 ,由于镀层剥落而造成磨粒磨损 ,磨损率剧增  相似文献   

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影响振压路机压实性的参数-压实参数,主要有:振动轮振幅A、激振频率W,激振力Fe,力的传递比Rr(土壤受力Fs与激振力Fe之比)。本文通过对“混沌”与“普通”振动压路机压实参数的对比,来比较“混沌”与“普通”振动压路机的压实性能。结果表明:“混沌”振动压路机的压实优性能优于“普通”振动压路机。  相似文献   

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The basic concepts about the active structures and some attributes of the modes were presented in paper “Liner Active Structures and Modes ( Ⅰ ) “. The characteristics of the active discrete systems and active beams were discussed, especially, the stability of the active structures and the orthogonality of the eigenvectors. The notes about modes were portrayed by a model of a seven-storeyed building with sensors and actuators. The concept of the adjoint active structure was extended from the discrete systems to the beams that were the representations of the continuous structures. Two types of beams with different placements of the measuring and actuating systems were discussed in detail. One is the beam with the discrete sensors and actuators, and the other is the beam with distributed sensor and actuator function. The orthogonality conditions were derived with the modal shapes of the active beam and its adjoint active beam. An example shows that the variation of eigenvalues with feedback amplitude for the homo-configuration and non-homo-configuration active structures.  相似文献   

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