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草地蝗虫种群数量消长数学模型研究 总被引:3,自引:1,他引:3
本文根据草地蝗虫发生特点,在充分考虑其数量消长受环境条件、敌害及本身内禀作用制约的基础上,提出了以时序为特点的几种主要蝗虫及混虫种群数量消长的数学模型。宽须蚁蝗、狭翅雏蝗及混合种群密度的拟合模型中z和x有较强的相关性,故这几个模型较好的反映了消长情况。但在混合种群消长模型中,自9月15日以后观测值迅速下降,而模型值并未很快下降,这是由于模型未考虑蝗虫生存的临界温度。 相似文献
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We present Turing pattern selection in a reaction—diffusion epidemic model under zero-flux boundary conditions. The value of this study is twofold. First, it establishes the amplitude equations for the excited modes, which determines the stability of amplitudes towards uniform and inhomogeneous perturbations. Second, it illustrates all five categories of Turing patterns close to the onset of Turing bifurcation via numerical simulations which indicates that the model dynamics exhibits complex pattern replication: on increasing the control parameter v, the sequence “H0 hexagons → H0-hexagon-stripe mixtures → stripes → Hπ-hexagon-stripe mixtures → Hπ hexagons” is observed. This may enrich the pattern dynamics in a diffusive epidemic model. 相似文献
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We present Turing pattern selection in a reaction-diffusion epidemic model under zero-flux boundary conditions.The value of this study is twofold.First,it establishes the amplitude equations for the excited modes,which determines the stability of amplitudes towards uniform and inhomogeneous perturbations.Second,it illustrates all five categories of Turing patterns close to the onset of Turing bifurcation via numerical simulations which indicates that the model dynamics exhibits complex pattern replication:on increasing the control parameter ν,the sequence "H 0 hexagons → H 0-hexagon-stripe mixtures → stripes → H π-hexagon-stripe mixtures → H π hexagons" is observed.This may enrich the pattern dynamics in a diffusive epidemic model. 相似文献
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中央空调系统节能控制的全局优化模型 总被引:1,自引:0,他引:1
首先通过分析得出商场内各产热单元的冷负荷,给出商场内总冷负荷关于人流量和商场温度的表达式;然后分别用优化方法和解超定方程方法求出商场内人流量随时间的变化;最后采用全局优化原理对中央空调系统的节能控制进行建模,实现了整个中央空调系统的能耗最小化. 相似文献
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