[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomat...[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.展开更多
In this paper, by using the theory of semigroup and spectrum, a computation formula on the growth order of one class of C0-semigroups in Banach space isproved.
It is known that the square of a ω-hyponormal operator is also ω-hyponormal. In this note it is showed that these exists an invertible operator which is not log-hyponormal but its integer powers are all ω-hyponorma...It is known that the square of a ω-hyponormal operator is also ω-hyponormal. In this note it is showed that these exists an invertible operator which is not log-hyponormal but its integer powers are all ω-hyponormal. MR Subject Classification 47B20 - 47A63 Keywords Lowner-Heinz inequality - ω-hyponormal - Furuta inequality Supported by Natural Science and Education Foundation of Henan Province.展开更多
The point spectrum and non-degenerate symplectic structure of eigenfunction systems of off-diagonal infinite dimensional Hamiltonian operator H=(■)are studied in this article.The necessary and sufficient conditions f...The point spectrum and non-degenerate symplectic structure of eigenfunction systems of off-diagonal infinite dimensional Hamiltonian operator H=(■)are studied in this article.The necessary and sufficient conditions for the eigenfunction systems of off-diagonal infinite dimensional Hamiltonian operator H to have non-degenerate symplectic structure are given.Further,the necessary and sufficient conditions for point spectrum to be contained in real axis,imaginary axis and other areas are obtained for off-diagonal infinite dimensional Hamiltonian operator H,respectively.As an illustrating example,off-diagonal infinite dimensional Hamiltonian operators derived from the plate bending problem and string vibration problem are used to justify the conclusions.展开更多
基金Supported by the Fund of Science and Technology in GuangXi Zhuang Autonomous Region(0009018)~~
文摘[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.
文摘In this paper, by using the theory of semigroup and spectrum, a computation formula on the growth order of one class of C0-semigroups in Banach space isproved.
基金Supported by Natural Science and Education Foundation of Henan Province
文摘It is known that the square of a ω-hyponormal operator is also ω-hyponormal. In this note it is showed that these exists an invertible operator which is not log-hyponormal but its integer powers are all ω-hyponormal. MR Subject Classification 47B20 - 47A63 Keywords Lowner-Heinz inequality - ω-hyponormal - Furuta inequality Supported by Natural Science and Education Foundation of Henan Province.
基金Supported by the National Natural Science Foundation of China(Grant No.11961022)the Natural Science Foundation of Inner Mongolia Autonomous Region(Grant Nos.2021MS01017,2021BS01007,2020ZD01)+3 种基金Inner Mongolia Higher Education Scientific Research Project(Grant Nos.NJZY21205,NJZY21208)University Basic Scientific Research Business Funding of Inner Mongolia(Grant No.ZSQN202216)Inner Mongolia“Grassland Talents”Industrial Innovation Talent Team ProjectResearch and Innovation Team Construction Plan of Hohhot Minzu College(Grant No.HM-TD-202005)。
文摘The point spectrum and non-degenerate symplectic structure of eigenfunction systems of off-diagonal infinite dimensional Hamiltonian operator H=(■)are studied in this article.The necessary and sufficient conditions for the eigenfunction systems of off-diagonal infinite dimensional Hamiltonian operator H to have non-degenerate symplectic structure are given.Further,the necessary and sufficient conditions for point spectrum to be contained in real axis,imaginary axis and other areas are obtained for off-diagonal infinite dimensional Hamiltonian operator H,respectively.As an illustrating example,off-diagonal infinite dimensional Hamiltonian operators derived from the plate bending problem and string vibration problem are used to justify the conclusions.
