人口素质的家庭影响因素分析

家庭是个体社会化的重要场所。家庭背景、家庭结构、家庭关系以及家庭教育等方面对人口素质有着不容忽视的影响 ,在当前家庭发生巨大变革的背景下 ,家庭变迁与人口素质呈动态关系 ,优化家庭因素对提高人口素质具有实践意义。     

论建立现代养老体系与弘扬传统养老文化

今后较长时间内 ,老年人自养、家庭养老、社会化养老等各种养老方式将同时存在、互为补充、不断发展演变 ,构成我国现代养老体系的基本框架。要从根本上解决人口老龄化问题 ,必须在建立现代养老体系的过程中 ,弘扬传统养老文化 ,只有这样 ,才能营造“尊老”、“敬老”的社会氛围 ,形成良好的“养老”社会环境 ,建设有中国特色的新型养老文化     

世纪末的俄罗斯人口问题和发展展望

２０世纪９０年代以来,随着经济的巨变,俄罗斯产生了一系列的人口问题,如高离婚率、低生育率与高人流比,多种原因造成人口素质下降、人才大量外流等。俄罗斯未来１５年人口数量将继续减少,人口素质略有提高,人口老龄化进程加快,人才外流状况短期内将难有改观。     

超大城市土地优化配置中的人口问题初探——以广州市为例

文章首先指出超大城市日益严重的土地资源短缺迫切要求城市土地的优化配置,然后以广州为例,具体阐述了在超大城市的土地优化配置中要如何重视与人口分布、管理的协调.     

老年人生活状况的城乡比较分析

本文利用 1996和 1997两年在厦门地区举行的城乡老年人日常生活及供养状况抽样调查资料 ,描述城区和农村两地老年人的背景特征 ,探讨老有所养、所医、所为和所乐等方面的城乡差别 ,在此基础上提出消除这些差别的几点对策。     

俄罗斯人口亏损问题初探

伴随着婚姻家庭领域出现的一系列不健康趋势 ,从 1992年开始 ,俄罗斯总人口数量逐年下降。俄罗斯家庭人口领域不良状况的出现 ,除文化方面的原因外 ,与国家经济状况的日下和不考虑家庭利益而实施的社会经济改革有直接关系。俄罗斯急待出台一套行之有效的家庭人口政策。本文介绍了俄罗斯目前的家庭人口状况 ,对人口亏损出现的原因做出分析 ,并提出改善方向     

Density-dependent growth and reproduction of the apple snail, Pomacea canaliculata : a density manipulation experiment in a paddy field

To examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint-marked snails of 15–20 mm shell height into 12 enclosures (pens) of 16 m² at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than 3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however, higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density. The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering period, was not significantly different among density treatments. These results suggest that snail density after the overwintering period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate the population of P. canaliculata in paddies. Received: October 23, 1998 / Accepted: July 16, 1999     

Economic development and labor force participation of older persons

The effect of economic development on labor force participation rates of older men and women is examined using national data for 134 countries. The analysis provides new insights into the evolution of retirement patterns with rising personal income, slowing population growth, the aging of the population, and shifts in the composition of employment. The analysis indicates a negative relationship between per capita income and labor force participation rates. This relationship is stronger for older men than for older women and is most apparent among middle income countries. An older population is associated with lower participation rates for older men and higher widow rates produce higher participation rates among older women. Industrial changes such as a decline in the proportion of the labor force employed in agriculture lower the proportion of older persons in the labor force. Finally, national social security policies are shown to impact the proportion of older persons that remains in the labor force.     

人口转变完成后的中国人口老龄化

在人口转变完成之后。由于人口惯性的存在,人口老龄化将比人口转变过程中的人口老龄化速度更快。中国已经基本完成人口转变,进入了人口老龄化的加速时期,老年人口比重和规模以及老年人口乘数均快速上升。因此,必须在思想上对人口老龄化问题真正重视,实现人口政策和人口工作的重心从控制人口数量向数量与结构并重转变,并尽快完善我国的养老保障制度。     

人口密度、平均工资、公共交通与城市商圈发展

文章引入城市人口密度、城市在岗职工平均工资和年末实有公共（汽）电车运营数三个变量,作为影响城市商圈发展的自变量系统。在提出假设的基础上,论证了他们与城市商圈发展之间呈同向关系。弹性系数分别为0.30、0.96、0.84,表明城市人口密度、城市在岗职工平均工资和年末实有公共（汽）电车运营数三个变量各自分别每提高1％.城市商圈发展分别增长0.30％、0.96％、0.84％。提出通过大力发展社会生产,提高城镇居民人均工资水平;消除贫富两级分化,建设和谐社会;加快发展城市公共交通,完善城市基础设施建设等措施,优化城市商圈消费环境、提高和完善城市商圈服务功能,促进城市商圈的可持续发展。