In this paper, we study the n-species biological systemwe get sufficient conditions for the existence of the invariant plane to system (1) whenm=1 and m = 2, we also get sufficient conditions for the eristence and sta...In this paper, we study the n-species biological systemwe get sufficient conditions for the existence of the invariant plane to system (1) whenm=1 and m = 2, we also get sufficient conditions for the eristence and stability ofthe heteroclinic cycle to system (1) when m = 1 and m = 2. In the case m = 1 andn = 3, we get conditions for the existence and stability of the heteroclinic cycle on theinvariant plane of system (1). In this case, we also prove that there is a center insidethe heteroclinic cycle and bounded by this heteroclinic cycle.展开更多
This paper gives a sufficient condition for the existence of heteroclinic cycle in the model of competition between n species and a criterion for determining the stability of the heteroclinic cycle. The results given ...This paper gives a sufficient condition for the existence of heteroclinic cycle in the model of competition between n species and a criterion for determining the stability of the heteroclinic cycle. The results given in this paper extend the results obtained by May and Leonard in [1]and by Hofbaner and Sigmund in [2]. A conjecture on the permanence of the model and a open problem on the stability of the heteroclinic cycle for the critical case are given at the end of this paper.展开更多
Leaves of multipurpose tree species （those providing more than one function or product of human use） can serve as sources of fer- tilizer for nutrient supply, especially nitrogen （N）. In this study chopped leaves ...Leaves of multipurpose tree species （those providing more than one function or product of human use） can serve as sources of fer- tilizer for nutrient supply, especially nitrogen （N）. In this study chopped leaves of tropical tree species （5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species） were in- corporated in soil to evaluate its effects on wheat biological productivity （including grain yield, GyIELD） under dryland conditions. High quality leaves of N-fixing tree species （e.g. Dalbergia sissoo, Cassia fistula and Prosopis cineraria） had lower carbon/nitrogen （C/N）, lignin/nitrogen （L^o/N）, polyphenol/nitrogen （PPt/N） and lignin＋polyphenol /nitrogen （L~＋PpL/N） ratios than low quality leaves of non-N-fixing species. Com- bination treatments had intermediate values of different parameters, Application of high quality leaves caused greater increases in wheat productivity and yield than other species.展开更多
文摘In this paper, we study the n-species biological systemwe get sufficient conditions for the existence of the invariant plane to system (1) whenm=1 and m = 2, we also get sufficient conditions for the eristence and stability ofthe heteroclinic cycle to system (1) when m = 1 and m = 2. In the case m = 1 andn = 3, we get conditions for the existence and stability of the heteroclinic cycle on theinvariant plane of system (1). In this case, we also prove that there is a center insidethe heteroclinic cycle and bounded by this heteroclinic cycle.
文摘This paper gives a sufficient condition for the existence of heteroclinic cycle in the model of competition between n species and a criterion for determining the stability of the heteroclinic cycle. The results given in this paper extend the results obtained by May and Leonard in [1]and by Hofbaner and Sigmund in [2]. A conjecture on the permanence of the model and a open problem on the stability of the heteroclinic cycle for the critical case are given at the end of this paper.
基金supported by Ministry of Environment and Forests,New Delhi,India
文摘Leaves of multipurpose tree species （those providing more than one function or product of human use） can serve as sources of fer- tilizer for nutrient supply, especially nitrogen （N）. In this study chopped leaves of tropical tree species （5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species） were in- corporated in soil to evaluate its effects on wheat biological productivity （including grain yield, GyIELD） under dryland conditions. High quality leaves of N-fixing tree species （e.g. Dalbergia sissoo, Cassia fistula and Prosopis cineraria） had lower carbon/nitrogen （C/N）, lignin/nitrogen （L^o/N）, polyphenol/nitrogen （PPt/N） and lignin＋polyphenol /nitrogen （L~＋PpL/N） ratios than low quality leaves of non-N-fixing species. Com- bination treatments had intermediate values of different parameters, Application of high quality leaves caused greater increases in wheat productivity and yield than other species.
