Global dynamics near the resonance in the sine-gordon equation

樱椋睿澹牵铮颍洌铮? ＥｑｕａｔｉｏｎTX１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｎｏｎｌｉｎｅａｒｄｙｎａｍｉｃｓｏｆｔｈｅｄａｍｐｅｄｄｒｉｖｅｎｓｉｎｅ－Ｇｏｒｄｏｎｅｑｕａｔｉｏｎｕｔ－ｕｘｘ＋ｓｉｎｕ＝－ε（αｕｔ＋Γｃｏｓωｔ）,（１．１）ｗｈｅ?..     

Bifurcation analysis in a predator-prey system with stage-structure and harvesting

In this paper, we consider a predator-prey model with stage-structure and harvesting. This model is the same as the one developed by Kar and Pahari (2007) [9], but we make bifurcation analysis more general than their work. In particular, using the approach of Beretta and Kuang (2002) [4], we show that the positive steady state can be destabilized through a Hopf bifurcation. We also investigate the stability and direction of periodic solutions bifurcating from Hopf bifurcation by using the normal form theory and the center manifold theorem presented in Hassard et al. (1981) [8]. Numerical simulations are then carried out as supporting evidences of our analytical results.     

一泛函微分系统的稳定性和Hopf分支

本文给出了一3维泛函微分系统的平衡点的全时滞稳定的代数判据,并讨论给出了该系统存在Hopf分支的条件。     

断裂力学的数值计算方法的研究现状与展望

介绍了当前用于断裂力学研究的多种数值计算方法。详细分析了有限元法、边界元法、无网格法、数值流形方法和小波数值方法等计算方法的特点及其在断裂力学研究中的应用现状，并探讨了断裂力学数值计算方法研究的发展趋势．     

Calculation of Coefficients of Simplest Normal Forms of Hopf and Generalized Hopf Bifurcations

Consider the following dynamical system x.=f(x),x∈Rn(1)wherexis the state vector andfis analytic, assumingthatx=0 is an equilibrium of system (1), i.e.f(0) =0. Further, suppose that the Jacobian matrixevaluated on the equilibriumx=0 presents a purelyimag…     

Selecting harvesting in a predator-prey system with stage structure for prey

In this papěr, we have considered a prey-predator system with selective harvesting of predator species. The stability of the passes through a sequence of critical values.     

一类次黎曼流形上测地线的研究

构造了一类步数为2(k+1)的次黎曼流形,讨论了其上面连接原点和适当远点的奇异测地线的存在性.     

弱量子超代数wHdq(g)的弱Hopf代数结构

定义了一个弱量子超代数wHqd(g),其中g=D(n,1)是一个李超代数.构造了wHdq(g)的一个弱Hopf代数结构.     

排气歧管温度场对矿用防爆柴油机防爆性能的影响

采用PRO/E三维建模软件及数值模拟方法对排气歧管进行建模,利用ANSYS软件,研究排气歧管在额定功率工况下循环工作状态的瞬态温度场,并给出了相应的仿真结果。结果表明：该排气管能够满足安全防爆的要求。     

非线性控制系统的一般形式及其稳定性

给出了SISO非线控制系统的点相对阶的概念,以此得出一般Brrnes Isidori标准形式。并对于具有最小相位非线性系统,给出了渐近稳定的充分条件;对于具有非最小相位系统,通过设计控制器来构建中心流形的方法,给出了其渐近稳定性的证明