The essential oil of the whole fruit and the peel of Anli pear (Pyrus Ussriensis Maxim.)grown in the western region of Liaoning Province was extracted through the hydrodistillationmethod, and was investigated by gas c...The essential oil of the whole fruit and the peel of Anli pear (Pyrus Ussriensis Maxim.)grown in the western region of Liaoning Province was extracted through the hydrodistillationmethod, and was investigated by gas chromatography-mass spectrometry (GC-MS) technique.The yields of the essential oils of Anli pear whole fruit and the peel were 0.073 and0.36%, respectively. The identification of the volatile compounds was conducted throughthe commercial National Institute of Science and Technology (NIST) and Wiley massspectral search program, confirmed by comparing the retention indices with standardvalues of authentic samples. A total of 7 and 16 components were identified from theessential oils of the peel and the whole fruit, respectively. The predominant constituentof the two kinds of essential oils was butylated hydroxytoluene, which is a typicalantioxidant.展开更多
Based on Chun-Ching Shih’s idea,the basic transform was substituted and the quasi-Chun-Ching Shih’s fractional Fourier transform with periodicity of 2,3 and M was deduced.The two former transforms and the Chun-Ching...Based on Chun-Ching Shih’s idea,the basic transform was substituted and the quasi-Chun-Ching Shih’s fractional Fourier transform with periodicity of 2,3 and M was deduced.The two former transforms and the Chun-Ching Shih’s fractional Fourier transform were only the particular cases of quasi-Chun-Ching Shih’s fractional Fourier transform with periodicity of M.展开更多
A mathematical model of a predator-prey model with Ivlev’s functional response concerning integrated pest management (IPM) is proposed and analyzed. We show that there exists a stable pest-eradication periodic soluti...A mathematical model of a predator-prey model with Ivlev’s functional response concerning integrated pest management (IPM) is proposed and analyzed. We show that there exists a stable pest-eradication periodic solution when the impulsive period is less than some critical values. Further more, the conditions for the permanence of the system are given. By using bifurcation theory, we show the existence and stability of a positive periodic solution. These results are quite different from those of the corresponding system without impulses. Numerical simulation shows that the system we consider has more complex dynamical behaviors. Finally, it is proved that IPM stragey is more effective than the classical one.展开更多
In this paper the management model a two-species fishery involving impulsesis investigated by using optimal impulsive control theorem. Optimal impulsive harvesting times andthe corresponding optimal harvesting populat...In this paper the management model a two-species fishery involving impulsesis investigated by using optimal impulsive control theorem. Optimal impulsive harvesting times andthe corresponding optimal harvesting population levels in different cases are obtained.展开更多
In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the line...In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the linear stability and instability of trivial and semi-trivial periodic solutions. Moreover, we use standard bifurcation theory to show the existence of coexistence states which arise near the semi-trivial periodic solution. As an application, we also examine some special case of the system to confirm our main results.展开更多
文摘The essential oil of the whole fruit and the peel of Anli pear (Pyrus Ussriensis Maxim.)grown in the western region of Liaoning Province was extracted through the hydrodistillationmethod, and was investigated by gas chromatography-mass spectrometry (GC-MS) technique.The yields of the essential oils of Anli pear whole fruit and the peel were 0.073 and0.36%, respectively. The identification of the volatile compounds was conducted throughthe commercial National Institute of Science and Technology (NIST) and Wiley massspectral search program, confirmed by comparing the retention indices with standardvalues of authentic samples. A total of 7 and 16 components were identified from theessential oils of the peel and the whole fruit, respectively. The predominant constituentof the two kinds of essential oils was butylated hydroxytoluene, which is a typicalantioxidant.
文摘Based on Chun-Ching Shih’s idea,the basic transform was substituted and the quasi-Chun-Ching Shih’s fractional Fourier transform with periodicity of 2,3 and M was deduced.The two former transforms and the Chun-Ching Shih’s fractional Fourier transform were only the particular cases of quasi-Chun-Ching Shih’s fractional Fourier transform with periodicity of M.
基金Supported by National Natural Science Foundation of China (No.10171106)
文摘A mathematical model of a predator-prey model with Ivlev’s functional response concerning integrated pest management (IPM) is proposed and analyzed. We show that there exists a stable pest-eradication periodic solution when the impulsive period is less than some critical values. Further more, the conditions for the permanence of the system are given. By using bifurcation theory, we show the existence and stability of a positive periodic solution. These results are quite different from those of the corresponding system without impulses. Numerical simulation shows that the system we consider has more complex dynamical behaviors. Finally, it is proved that IPM stragey is more effective than the classical one.
基金This research is supported by the Foundation of Educational Committee of Liaoning Province (No.20331080)
文摘In this paper the management model a two-species fishery involving impulsesis investigated by using optimal impulsive control theorem. Optimal impulsive harvesting times andthe corresponding optimal harvesting population levels in different cases are obtained.
基金This research is supported by the National Natural Science Foundation of China (10171106).
文摘In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the linear stability and instability of trivial and semi-trivial periodic solutions. Moreover, we use standard bifurcation theory to show the existence of coexistence states which arise near the semi-trivial periodic solution. As an application, we also examine some special case of the system to confirm our main results.
