采用单边拉氏变换进行系统分析的讨论

为深入理解系统分析的复频域分析法，澄清某些模糊概念，本文首先阐述了用单边拉氏变换进行系统分析的必要性。进而对ｔ＜０的激励信号对ｔ≥０响应的影响、“０－系统”与“０＋系统”的异同、用Ｙ（ｓ）＝Ｈ（ｓ）Ｆ（ｓ）求零状态响应的条件等几个易于产生歧义的问题进行了分析讨论     

Time-stepping for multibody dynamics with friction-affected bilateral constraints

The dynamics of multibody systems with friction-affected bilateral constraints is essentially different from those of smooth multibody systems.In this paper,general modeling and numerical methods for this kind of friction-affected system are given.Each friction-affected bilateral constraint is modeled by splitting it into two unilateral constraints opposite to each other.The constraint equalities are replaced with complementarity inequalities to avoid the absolute value terms in the dynamic equations.A linear complementarity problem time-stepping scheme is presented for simulation that does not suffer from the difficulties of enumeration (known as Delassus' problem).The algorithm has the advantage that it needs no detection for stick-slip transition when neglecting the difference between the static and kinetic friction coefficients.Our method is carried out in an example to analyze the nonsmooth nonlinear behavior of a typical mechanism.     

一类单边算子权移位的谱

本文首先给出重数有限的单边算子权移位的等价表示,进而对一类具有下(上)三角权的移位给出简单方便的计算谱的方式.     

单边增长条件下2n阶常微分方程的奇周期解

本文讨论了一类2n阶微分方程周期解的存在性,其中 n 是正整数. 运用Leray-Schauder不动点定理与Fourier分析的方法,在允许非线性项f超线性增长的条件下,本文获得了该方程的奇周期解.     

变质量单面完整约束系统的Lie对称性与守恒量

研究变质量单面完整约束系统的Lie 对称性与守恒量. 首先利用微分方程在无限小群变换下的不变性建立了系统的Lie 对称性的确定方程,给出了结构方程和守恒量;其次研究了系统的Lie 对称性逆问题;最后举例说明结果的应用.