By means of theory of toplogical degree in nonlinear functional analysis combining with qualitative analysis method in ordinary differential equations, we discuss the existence of nontrivial periodic orbits for higher...By means of theory of toplogical degree in nonlinear functional analysis combining with qualitative analysis method in ordinary differential equations, we discuss the existence of nontrivial periodic orbits for higher dimensional autonomous system with small perturbations.展开更多
In this study, phylogenetic relationships of 33 species belonging to 19 genera of Issidae and 1 outgroup （Paravarcia decapterix） were analyzed using maximum parsimony （MP） and Bayesian inference （BI） methods bas...In this study, phylogenetic relationships of 33 species belonging to 19 genera of Issidae and 1 outgroup （Paravarcia decapterix） were analyzed using maximum parsimony （MP） and Bayesian inference （BI） methods based on partial sequences of the nuclear 18S rDNA and wingless genes （Wg）. The topologies of the phylogenetic trees generated from different methods were quite similar. The phylogenetic analysis divided Issidae into five subfamilies： Caliscelinae, Tonginae, Parahiraciinae, Hemisphaeriinae and Issinae. The results also supported that the genus Eusudasina should be transferred from Issinae to Hemisphaeriinae.展开更多
All the symplectic matrices possessing a fixed eigenvalue ω on the unit circle form a hypersurface in the real symplectic group Sp(2n). This paper is devoted to the study of the topological structures of this hypersu...All the symplectic matrices possessing a fixed eigenvalue ω on the unit circle form a hypersurface in the real symplectic group Sp(2n). This paper is devoted to the study of the topological structures of this hypersurface and its complement in Sp(2n).展开更多
文摘By means of theory of toplogical degree in nonlinear functional analysis combining with qualitative analysis method in ordinary differential equations, we discuss the existence of nontrivial periodic orbits for higher dimensional autonomous system with small perturbations.
基金supported by the National Natural Science Foundation of China(31372234,30970388)the Ministry of Education of China(TS2011XBNL061)Fauna Sinica(2006FY120100)under the Ministry of Science and Technology of China
文摘In this study, phylogenetic relationships of 33 species belonging to 19 genera of Issidae and 1 outgroup （Paravarcia decapterix） were analyzed using maximum parsimony （MP） and Bayesian inference （BI） methods based on partial sequences of the nuclear 18S rDNA and wingless genes （Wg）. The topologies of the phylogenetic trees generated from different methods were quite similar. The phylogenetic analysis divided Issidae into five subfamilies： Caliscelinae, Tonginae, Parahiraciinae, Hemisphaeriinae and Issinae. The results also supported that the genus Eusudasina should be transferred from Issinae to Hemisphaeriinae.
基金Partially supported by NNSFMCSEC of ChinaQiu Shi Sci Tech. Foundation
文摘All the symplectic matrices possessing a fixed eigenvalue ω on the unit circle form a hypersurface in the real symplectic group Sp(2n). This paper is devoted to the study of the topological structures of this hypersurface and its complement in Sp(2n).
