维普中文期刊产品整合服务
3篇 您的检索式:作者名="ZHANGLiqun"
    题名 作者 年代 出处 被引量
1Improving biocontrol activity of Pseudomonas fluorescens through chromosomal inte-gration of 2,4-diacetylphloro-glucinol biosynthesis genes显示文摘Antibiotic 2,4-diacetylphloroglucinol (2,4- DAPG) produced by Pseudomonas fluorescens CPF-10 and 2P24 is a principal factor enabling bacteria to suppress plant diseases caused by soilborne pathogens. In this study, a 2,4-DAPG biosynthesis locus phlACBDE cloned from strain CPF-10 was assembled into a mini-Tn5 transposon and in- troduced into the chromosome of P. fluorescens P32 (2,4- DAPG?), CPF-10 and 2P24 to construct the 2,4-DAPG over- producing derivatives P32-38, CPF10-9 and 2P24-48, respec- tively. All the transgenic strains showed an enhanced anti- biosis capacity against plant microbial pathogens in vitro and two strains, P32-38 and CPF10-9, provided significantly bet- ter protection against wheat take-all disease caused by Gae- umannomyces graminis var. tritici and tomato bacterial wilt caused by Ralstonia solanacearum in greenhouse. Compared to their parental strains, the 2,4-DAPG overproducing de- rivatives colonized to the same extent on the wheat tips in the autoclaved soil, but developed larger populations in natural soil. These results indicated that production of antibiotics 2,4- DAPG by biological control pseudomonads can contribute not only to their disease suppression capacities but also to the ecological competence in the resident microflora. Our re- search also suggests that it is a realistic approach to improve biocontrol capacity of P. fluorescens through the genetic modification of its antibiotic 2,4-DAPG production.ZHOUHongyou WEIHailei LIUXili WANGYe ZHANGLiqun TANGWenhua 2005Chinese Science Bulletin2005,50,8:4
2Robust stability analysis of uncertain discrete-time systems with state delay显示文摘The sufficient conditions of stability for uncertain discrete-time systems with state delay have been proposed by some researchers in the past few years, yet these results may be conservative in application. The stability analysis of these systems is discussed, and the necessary and sufficient condition of stability is derived by method other than constructing Lyapunov function and solving Riccati inequality. The root locations of system characteristic polynomial, which is obtained by augmentation approach and Laplace expansion, determine the stability of uncertain discrete-time systems with state delay, the system is stable if and only if all roots lie within the unit circle. In order to analyze robust stability of system characteristic polynomial effectively, Kharitonov theorem and edge theorem are applied. Example shows the practicability of these methods.RenZhengyun ZhangLiqun ShaoHuihe 2004Journal of Systems Engineering and Electronics2004,15,2:0
3Optimal closed-loop identification test design for internal model control显示文摘In this paper, optimal closed-loop test design for control is studied. The identified model is used for controller design. The control scheme used is internal model control (IMC) and the design constraint is the power of the process output or that of the reference signal. The measure of performance is the variance of the error between the output of the ideal closed-loop system (with the ideal controller) and that of the actual closed-loop system (with the controller computed from the identified model). Optimal spectrum formulae can be used to determine the PRBS signal in industrious identification.ZhangLiqun ShaoHuihe DaiDan 2004Journal of Systems Engineering and Electronics2004,15,4:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费