We consider a system of neutral equations with unbounded delay, and derive conditions on Liapunov functionals to ensure that the solutions are uniformly bounded and uniformly ultimately bounded.
本文探讨了已往学者试图解释重动句的形成,分类及其句法语义特征等所存在的种种问题,然后根据动词所表现的事件类型(typology of events)尝试从语义上对重动句进行分类。并通过语言事实论证"宝玉骑马骑累了"这类重动句的动词...本文探讨了已往学者试图解释重动句的形成,分类及其句法语义特征等所存在的种种问题,然后根据动词所表现的事件类型(typology of events)尝试从语义上对重动句进行分类。并通过语言事实论证"宝玉骑马骑累了"这类重动句的动词复制(verb copying)不是因为移位(moving)或为了满足汉语句法中的"短语结构条件"(Phrase structure constraint),而是要让表完成体态的"得""到""了""过"等在句中能够得以实现。展开更多
In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f...In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f(x)≠0,the system is non-Hamiltonian,so we have to introduce some reversibility assumptions to apply a suitable twist theorem,for reversible maps with small twist.Moreover,when the nonnegative parameterαdecreases to 0,the system becomes discontinuous.In this case,we need to introduce some suitable transformations to overcome the lack of regularity.We will prove that for any nonnegative parameterα,when p(t)is an odd periodic function satisfying∣∣∫2π0p(t)sintdift∣∣<4,all the solutions are bounded;when p(t)satisfies∣∣∫2π0p(t)sintdift∣∣>4,the SD oscillator has unbounded solutions,and when p(t)satisfies∣∣∫_(0)^(2π)p(t)sintdift∣∣≥4+|F|_(∞),all the solutions are unbounded.展开更多
This paper considers a class of p-NFDEs. By Liapunov functionals, we establish two boundedness criteria, which improve some boundedness conditions for FDEs in the literature. Some examples are also worked out to demon...This paper considers a class of p-NFDEs. By Liapunov functionals, we establish two boundedness criteria, which improve some boundedness conditions for FDEs in the literature. Some examples are also worked out to demonstrate the advantages of our results.展开更多
文摘We consider a system of neutral equations with unbounded delay, and derive conditions on Liapunov functionals to ensure that the solutions are uniformly bounded and uniformly ultimately bounded.
基金supported by the Key Research Funds for the Universities of Henan Province(No.19A110018)the Foundation for Key Teachers of Henan Polytechnic University(No.2022XQG-09)。
文摘In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f(x)≠0,the system is non-Hamiltonian,so we have to introduce some reversibility assumptions to apply a suitable twist theorem,for reversible maps with small twist.Moreover,when the nonnegative parameterαdecreases to 0,the system becomes discontinuous.In this case,we need to introduce some suitable transformations to overcome the lack of regularity.We will prove that for any nonnegative parameterα,when p(t)is an odd periodic function satisfying∣∣∫2π0p(t)sintdift∣∣<4,all the solutions are bounded;when p(t)satisfies∣∣∫2π0p(t)sintdift∣∣>4,the SD oscillator has unbounded solutions,and when p(t)satisfies∣∣∫_(0)^(2π)p(t)sintdift∣∣≥4+|F|_(∞),all the solutions are unbounded.
文摘This paper considers a class of p-NFDEs. By Liapunov functionals, we establish two boundedness criteria, which improve some boundedness conditions for FDEs in the literature. Some examples are also worked out to demonstrate the advantages of our results.
