城市区域性人口承载力动态综合测度

对马尔萨斯人口增长模型进行研究,设计人口承载力发展路径和基于增长模型的隶属函数,从概率角度构建人口承载力动态综合测度模型,同时,以城市区域为研究对象,以经济作为人口承载力主导影响因素,辅之以自然、环境、资源与科技因素,构建人口承载力综合评价指标体系,多角度、多因素分析区域人口承载力,寻找人口承载短板,为人口承载力研究提供新的研究方法和视角.实证研究结论显示,研究区域人口承载力当前处于承载力强阶段,并开始向适度阶段过渡,其内部指标和子系统发展不平衡,人口系统自身发展稳定,经济和环境人口承载力强,资源和科技承载力较弱,随着区域经济的发展,在相当长一段时间内可进入适度人口阶段.     

随机种群模型数值解的均方散逸性

讨论了随机种群模型数值解的均方散逸性,基于步长受限制和无限制的两种条件,利用补偿的和无补偿的数值方法研究了随机种群模型数值解的均方散逸性.从而得出补偿的数值算法更适合解决随机种群模型数值解的均方散逸性问题.     

The population‐level impact of HBV and its vaccination on HIV transmission dynamics

Hepatitis B virus (HBV) and its vaccination strategy may affect human immunodeficiency virus (HIV) transmission dynamics because both viruses have synergistic effects. To quantitatively assess the potential impact of HBV and its vaccination strategy on HIV transmission dynamics at the population level, in this paper, we formulate a deterministic compartmental model that describes the joint dynamics of HBV and HIV. We first derive the explicit expressions for the basic reproduction numbers of HIV and HBV and analyze the dynamics of HIV and HBV subsystems, respectively. Then a systematic qualitative analysis of the full system is also provided, which includes the local and global behavior. By using a set of reasonable parameter values, the full system is numerically investigated to assess the potential impact of HBV and its vaccination strategy on HIV transmission. The direct and indirect population level impact of HBV on HIV is demonstrated by calculating the fraction of HIV infections attributable to HBV and the difference between HIV prevalence in the presence and absence of HBV, respectively. The findings imply that the increase of HBV vaccination rate may unusually accelerate HIV epidemics indirectly, although the direct effect of HBV on HIV transmission decreases as HBV vaccination rate increases. Finally, the potential impact of HIV on HBV transmission dynamics is investigated by way of parenthesis. Copyright © 2016 John Wiley & Sons, Ltd.     

On analytical and numerical approaches to division and label structured population models

Even among cells in the same population, the concentration of a protein or cellular constituent can vary considerably. This heterogeneity can arise from several sources, including differences in kinetic rates between cells and distribution of cellular constituents through cell division. Compartmental models have been used to describe the distribution of the number of divisions undergone by cells in a population. More recently, such models have been coupled with the dynamics of intracellular labels and analytical solutions to the division and label structured population equations have been found. However, such approaches have thus far focused on simple models of intracellular dynamics such as the decay of an intracellular label. In this work, we demonstrate that analytical solutions are possible for more general forms of intracellular dynamics offering the promise to lend mathematical insight into population dynamics in more realistic biological settings.     

Non-destructive assessment of parchment deterioration by optical methods

A non-destructive and non-invasive method for quantitative characterization of parchment deterioration, based on spectral measurements, is proposed. Deterioration due to both natural aging (ancient parchments) and artificial aging (achieved by means of controlled UV irradiation and temperature treatment) was investigated. The effect of aging on parchment native fluorescence was correlated with its deterioration condition. Aging causes fluorescence intensity drop, spectral shift of the main peak, and an overall change in the fluorescence spectral features. Digital color imaging analysis based on visible reflectance from the parchment surface was also applied, and the correspondent color components (RGB) were successively correlated with the state of parchment deterioration/aging. The fluorescence and color imaging data were validated by analysis of historical parchments, aged between 50 and 2000 years and covering a large variety of states of deterioration. The samples were independently assessed by traditional microscopy methods. We conclude that the proposed optical method qualifies well as a non-destructive tool for rapid assessment of the stage of parchment deterioration.     

Oscillation and stability of nonlinear discrete models exhibiting the Allee effect

In this paper, we consider the discrete nonlinear delay population model exhibiting the Allee effect

The Effect of Incoherent Population Pumping on Squeezing in Resonance Fluorescence

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A Semigroup Approach to Nonlinear Equation of Age-dependent Population Dynamics

This paper deals with nonlinear model, of age-dependent population dynamics, with nonautonomous time dependence. Using a nonlinear semigroup approach, the authors prove the existence of the problem under general assumptions.     

改革开放后中国流动人口迁移机制研究

具有社会和空间双重转换特征的人口流动是社会主义市场经济发展的客观要求和必然结果.本文在评述国际上有关流动人口迁移机制理论的荃础上,系统地分析了中国流动人口的成因,归纳总结了有关流动人口发展趋势与改革、解除阻止人口流动的制度和政策的四点结论.     

我国运动稳定性研究的新进展

综述了近年来我国运动稳定性(包括力学系统、控制系统、人口系统、生态系统和大系统的稳定性)及其一般理论的研究进展。