Then,with the inter-provincial migration factor introduced and the rate of net migration calculated,the population size and structure of Shaanxi Province between 2001 and 2050 has been predicted.
the author's viewpoint is that with the coming of information age and the development of knowledge economy, education investment capacity should be one of the most important factors measuring the proper scale of population.
It is analyzing on the difference between people's capacity and people's scale and foundation of contacting mainly, do the rational scale of population in order to define.
To realize population and economy sustainable development, we should moderately develop population scope, reasonably adjust population structure, greatly improve population quality.
The article used the possibility-satisfaction degree method of system engineering to build a forecasting model of the reasonable population scope in Shanghai city. It incorporates lots of factors in five aspects that are the level of economics, social living, level of resources, environments and strength requirement and finds the reasonable population scope and the conditions that the scope relies on at an objective time. The article made different kinds of acuity degree analysis of key influence factors and got some policy conclusion.
mediohispanicum was generalized both at the regional and local (population) scale, since its flowers were visited by more than 100 species of insects with very different morphology, size and behaviour.
However, this frequency being low - 15 % over the last decade - the results at population scale are not much penalised and that inexperienced birds do not seem to be as much responsible for breeding malfunctions as one might be led to expect.
Contiguous resistant and sensitive herds with similar pre-epidemic density were detected on a smaller population scale, suggesting complementary mechanisms intervening besides density-dependence as determinants of the outbreak outcome.
Epidemiologic model of SIS type has a delay corresponding to the infectious period and disease-related deaths, so that the population size is variable.
Moreover, when σ>amp;gt;1, the local or global asymptotical stability of endemic equilibrium for DI model with constant population size in n-dimensional or two-dimensional space is obtained.
A range-wide survey of Dakotaskipper (Hesperia dacotae) populationsassessed levels of genetic variability andgeographic scale of population structure inthis species of conservation concern.
An indirect means of assessing realized larval dispersal - and hence geographic scale of population 'openness' - is available from analyses of population genetic differentiation.