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Your search keyword '"Wei, Chunjin"' showing total 49 results
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49 results on '"Wei, Chunjin"'

8. Bifurcation analysis of a delayed reaction–diffusion–advection Nicholson's blowflies equation.

Author

Tan, Mengfan, Wei, Chunjin, and Wei, Junjie

Subjects
*BLOWFLIES, *HOPF bifurcations, *ADVECTION, *EQUATIONS
Abstract

In this paper, we investigate the dynamics of a reaction-diffusion Nicholson's blowflies equation with advection. The stability of positive steady state and existence of Hopf bifurcation are obtained by analyzing the distribution of the eigenvalues. Moreover, by using the center manifold theory and normal form method, an explicit algorithm for determining the direction and stability of the Hopf bifurcation is derived. Meanwhile, we find out that the bifurcation value is increasing with respect to the advection rate. Finally, numerical results demonstrate that the advection term causes the population to move from upstream to downstream, which also indicates that advection term plays a key role in the description and interpretation of some common natural phenomena. [ABSTRACT FROM AUTHOR]

Published
2024
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33. A stochastic predator–prey model with Holling II increasing function in the predator.

Author

Huang, Youlin, Shi, Wanying, Wei, Chunjin, and Zhang, Shuwen

Subjects
STOCHASTIC models, LOTKA-Volterra equations, PREDATORY animals, PREDATION, COMPUTER simulation
Abstract

This paper is concerned with a stochastic predator–prey model with Holling II increasing function in the predator. By applying the Lyapunov analysis method, we demonstrate the existence and uniqueness of the global positive solution. Then we show there is a stationary distribution which implies the stochastic persistence of the predator and prey in the model. Moreover, we obtain respectively sufficient conditions for weak persistence in the mean and extinction of the prey and extinction of the predator. Finally, some numerical simulations are given to illustrate our main results and the discussion and conclusion are presented. [ABSTRACT FROM AUTHOR]

Published
2021
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34. Dynamics of a stochastic three-species nutrient-phytoplankton-zooplankton model

Author

Wei Chunjin, Zhang Shuwen, Lan Guijie, and Fu Yingjie

Subjects
education.field_of_study, Extinction, Applied Mathematics, General Neuroscience, Population, White noise, Stability (probability), Zooplankton, General Biochemistry, Genetics and Molecular Biology, Phytoplankton, Quantitative Biology::Populations and Evolution, Initial value problem, Applied mathematics, education, Mathematics, Deterministic system
Abstract

We investigate a stochastic three-species nutrient-phytoplankton-zooplankton model in this paper. We verify that the system admits a unique positive global solution starting from any positive initial value firstly. Then the sufficient conditions that guarantee the population extinction and persistence in the mean are derived. The results show that weaker white noise will strengthen the stability of the system, while stronger white noise will result in extinction of population. We also show that around the positive equilibrium point of deterministic system, the stochastic system is weakly persistent in the mean under some conditions.

Published
2018

35. A research of pest management SI stochastic model concerning spraying pesticide and releasing natural enemies

Author

Fu Yingjie, Lan Guijie, Wei Chunjin, and Zhang Shuwen

Subjects
Lyapunov function, Comparison theorem, Integrated pest management, Stochastic modelling, Applied Mathematics, General Neuroscience, Boundary (topology), General Biochemistry, Genetics and Molecular Biology, symbols.namesake, Stochastic differential equation, Bounded function, symbols, Applied mathematics, Epidemic model, Mathematics
Abstract

In this paper, we study the dynamics of the stochastic SI epidemic model for pest management concerning spraying pesticide and releasing natural enemies. Existence of a unique global positive solution is proved firstly. And we show that the positive solution to the stochastic system is stochastically bounded. Third, by using Khasminshii's method and Lyapunov function, we derive the sufficient conditions for the existence of the nontrivial stochastically positive T-periodic solution. Then, by comparison theorem for stochastic differential equation, the sufficient conditions for existence and global attraction of the boundary periodic solution are obtained. Finally, Numerical simulations are carried out to substantiate the analytical results.

Published
2018

48. One-Step Synthesis of High-Quality Water-Soluble CdSe Quantum Dots Capped by N-Acetyl-L-cysteine via Hydrothermal Method and Their Characterization

Author

Wei, Chunjin, Li, Jinyu, Gao, Fang, Guo, Shuxia, Zhou, Yongcui, and Zhao, Dan

Abstract

Novel water-soluble CdSe quantum dots (QDs) have been prepared with N-acetyl-L-cysteine as new stabilizer through a one-step hydrothermal route. The influence of experimental conditions, including reaction time, molar ratio of reactants, and pH value, on the luminescent properties of the obtained CdSe QDs has been systematically investigated. The characterization of as-prepared QDs was carried out through different methods. In particular, we realized qualitative and semiquantitative studies on CdSe QDs through X-ray photoelectron spectroscopy and electron diffraction spectroscopy. The results show that the as-prepared CdSe QDs exhibit a high quantum yield (up to 26.7%), high stability, and monodispersity and might be widely used in biochemical detection and biochemical research.

Published
2015
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49. The impact of fear factor and self-defence on the dynamics of predator-prey model with digestion delay.

Author

Li J, Liu X, and Wei C

Subjects
Animals, Digestion, Food Chain, Population Dynamics, Models, Biological, Predatory Behavior
Abstract

In this paper, we propose both deterministic and stochastic predator-prey models with digestion delay, incorporating fear factor and self-defence. For the deterministic model, the existence and stability of the equilibrium are investigated and the occurrence of Hopf bifurcation is studied. For the stochastic model, we investigate the existence of a unique global positive solution of the model and analyze the asymptotic behavior of the global solution around the equilibriums of the deterministic model. Finally, numerical simulations are carried out to verify our analytical results, which indicate that the intensity of white noise, fear factor and self-defence have a significant relationship with the dynamics of the predator-prey model and expand the theoretical analyses.

Published
2021
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