[Objective] This study aimed to separate and purify antibacterial substances from soil Streptomyces sp. CaiF1, and to explore the activities of this substance. [Method] The antibacterial substances were separated and ...[Objective] This study aimed to separate and purify antibacterial substances from soil Streptomyces sp. CaiF1, and to explore the activities of this substance. [Method] The antibacterial substances were separated and purified by Ethyl acetate extraction, macroporous adsorptive resin, silica gel chromatography and preparative high performance liquid chromatography (HPLC), and powdery mildew were taken as the indicating bacterial to study their activities. [Result] Antibacterial substances were purified and the stability analysis of the extracts from Streptomyces CaiF1 fermentation broth showed very stable at pH 2.0-pH 10.0, 100 ℃ and changed very little under UV treatment for 24 h. Inhibition rate of powdery mildew was 69.7%. [Conclusion] The purified antibacterial substances showed good stability, which provided theoretical foundation for their structural identifications and future applications.展开更多
In this paper, we discuss the stability of general compound boundary value prob-lems combining Riemann boundary value problem for an open arc and Hilbert bound-ary value problem for a unit circle with respect to the p...In this paper, we discuss the stability of general compound boundary value prob-lems combining Riemann boundary value problem for an open arc and Hilbert bound-ary value problem for a unit circle with respect to the perturbation of boundary curve.展开更多
In this paper, we consider a nonlinear system of reaction diffusion equa- tions arising from mathematical neuroscience and two nonlinear scalar reaction diffusion equations under some assumptions on their coefficients...In this paper, we consider a nonlinear system of reaction diffusion equa- tions arising from mathematical neuroscience and two nonlinear scalar reaction diffusion equations under some assumptions on their coefficients. The main purpose is to couple together linearized stability criterion （the equivalence of the nonlinear stability, the linear stability and the spectral sta- bility of the standing pulse solutions） and Evans functions to accomplish the existence and instability of standing pulse solutions of the nonlinear system of reaction diffusion equations and the nonlinear scalar reaction diffusion equa- tions. The Evans functions for the standing pulse solutions are constructed explicitly.展开更多
基金Supported by National Natural Science Foundation of China （60474002, 60674041） and National High Technology Research and Development Program of China （863 Program） （2006AA04Z173）
文摘[Objective] This study aimed to separate and purify antibacterial substances from soil Streptomyces sp. CaiF1, and to explore the activities of this substance. [Method] The antibacterial substances were separated and purified by Ethyl acetate extraction, macroporous adsorptive resin, silica gel chromatography and preparative high performance liquid chromatography (HPLC), and powdery mildew were taken as the indicating bacterial to study their activities. [Result] Antibacterial substances were purified and the stability analysis of the extracts from Streptomyces CaiF1 fermentation broth showed very stable at pH 2.0-pH 10.0, 100 ℃ and changed very little under UV treatment for 24 h. Inhibition rate of powdery mildew was 69.7%. [Conclusion] The purified antibacterial substances showed good stability, which provided theoretical foundation for their structural identifications and future applications.
基金the Natural Science Foundation of Fujian Province (2008J0187).
文摘In this paper, we discuss the stability of general compound boundary value prob-lems combining Riemann boundary value problem for an open arc and Hilbert bound-ary value problem for a unit circle with respect to the perturbation of boundary curve.
基金supported by a Faculty Research Grant of Lehigh University
文摘In this paper, we consider a nonlinear system of reaction diffusion equa- tions arising from mathematical neuroscience and two nonlinear scalar reaction diffusion equations under some assumptions on their coefficients. The main purpose is to couple together linearized stability criterion （the equivalence of the nonlinear stability, the linear stability and the spectral sta- bility of the standing pulse solutions） and Evans functions to accomplish the existence and instability of standing pulse solutions of the nonlinear system of reaction diffusion equations and the nonlinear scalar reaction diffusion equa- tions. The Evans functions for the standing pulse solutions are constructed explicitly.
