鳜野生群体与养殖群体的RAPD分析

用60个随机引物对鳜Siniperca chuatsi Basilewsky野生群体和养殖群体进行随机扩增多态DNA(RAPD)分析,经过引物筛选,分别用55个和54个引物对野生鳜和养殖鳜进行群体内分析。结果表明,野生群体多态位百分率为85．75％,群体内遗传相似率和遗传距离分别为0．8547和0．1453;养殖群体多态位百分率为16．39％,遗传相似率和遗传距离分别为0．9527和0．0473;两群体间遗传相似率和遗传距离分别为0．6905和0．3095;鳜野生群体具有较高的遗传多样性,养殖群体的遗传多样性却显著降低,野生群体与养殖群体间有明显的遗传差异,说明人工繁育对鳜基因组造成了显著的影响。     

德保苏铁扶平居群与“回归项目”居群的调查

德保苏铁是我国特有种,为更好地了解其回归项目人工居群状况,为其今后的发展制定规划,2012年对其个体进行生长特性调查。（1）调查德保苏铁扶平居群结构,并绘制其分布图。将此次调查数据与2001年马晓燕等调查的数据对比,发现植株数量由2001年的785株下降致2012年的425株。扶平居群年龄结构呈倒金字塔型,扶平居群极度濒危,亟需有效保护。（2）调查扶平居群和黄连山居群（即＂回归自然项目＂居群）植株的形态指标并进行比较,人工居群的有茎干植株比、植株叶数均值都优于扶平居群的,说明德保苏铁回归自然项目已取得初步成功。     

不动点问题和广义联立变分不等式问题及混合平衡问题的迭代格式

在Hilbert空间中介绍了1种迭代序列,利用这种序列找出了混合平衡问题的解集和非扩张映射不动点问题的解集以及关于逆强单调的广义联立变分不等式问题解集的公共元.证明了在某些参数控制条件下,迭代序列强收敛于此公共元.     

分层混合均衡问题和不动点问题的等价性

在Hilbert空间中,介绍了一类改进的混合均衡问题,并在适当条件下研究了混合均衡问题与不动点问题的等价关系,进一步建立了关于分层混合均衡问题解的一个充分必要条件.     

一个迭代序列的不动点问题变分不等式问题及平衡问题

介绍了在Hilbert空间中求解平衡问题,非扩张映射不动点问题及变分不等式问题公共解的迭代序列.在一些参数控制条件下给出了迭代序列的强收敛定理.

Abstract：

This paper introduces the iterative sequences for finding the common solution of an equilibrium problem,a fixed point problem of a nonexpansive mapping and the variational inequality problem in a Hilbert space.Some strong convergence theorems of the iterative sequences are obtained under some parameter controlling conditions.     

Cross-national comparison of population density

The unresolved difficulties associated with defining and measuring population density strictly circumscribe the scope and nature of the conclusions that can be properly derived from differentials in man:land ratios. Any conclusions about human density will have meaning only to the extent that they are based on a recognition that this density must be viewed in both static and dynamic terms and that it cannot be isolated in analysis, from either the social and cultural setting, the demographic characteristics of the population, or the broader processes of social change within the society. In and of itself, the familiar man:land ratio says more about area than it does about either the human experience of density or the relation of population to resources. This ratio is therefore essentially meaningless as an indicator of comparative conditions of life among different countries and different geographic regions. The mere fact of having a relatively low average population density thus, does not automatically entitle a nation to complacency about its ability to adjust readily to future population change, either in terms of growth in numbers or in the geographic location of its people.