Sex similarities in occupational status attainment: Are the results due to the restriction of the sample to employed women?

Research on sex differences in occupational attainment suggests that working men and working women attain essentially the same mean level of occupational attainment and do so through quite similar processes. A possible explanation for these similarities is that the sample of working women contains an overrepresentation of successful women, since women who can afford not to work will stay out of the labor force unless they find a job commensurate with their education. This we define as a censoring problem. By extending a technique developed by Heckman, we can estimate the structural parameters for all women, regardless of current employment status. This procedure allows us to assess the impact of the censoring problem on women's occupational attainment equations.     

Size and duration of empires growth-decline curves, 3000 to 600 b.c.

Area changes of about 30 best known empires and states are compiled and tabulated. Superimposed and juxtaposed graphs (size versus time) help to visualize the relative size and location in time of these empires. Size-time integral, maximum stable size, adulthood date, and duration are defined operationally and are listed for 20 empires. A criterion is given for distinctness of successive empires. The size-time integral is a direct measure of an empire's impact on history insofar as that impact depends on sheer size and duration. The integral is largest for the Chinese Hsia-Shang, Egyptian New, Old, and Middle, Assyrian New, and Hittite empires. A world-wide territorial concentration index is tabulated. It increases during the period considered from 0.08 to 1.4% of the world dry land area.     

莱麦草染色体组分析及染色体变异的观察

通过对有丝分裂中期及减数分裂终变期染色体数目统计,形态、行为的观察,发现莱麦草染色体呈现广泛的变异：有丝分裂中期株内染色体数目在2n＝11──56内变化,含有本物种染色体数目2n＝28的细胞仅占统计数的27．8％。减数分裂终变期出现36％具非整倍性的花粉母细胞,染色体数除数目变异外还有结构变异如Robertson易位等。本文对该种进行了染色体组分析,确认其为同源四倍体。同时对该物种株内产生混倍性的原因,在物种进化上的意义进行了探讨。     

Seasonal forcing on the dynamics ofClethrionomys rufocanus: Modeling geographic gradients in population dynamics

We interpret gradients in population dynamics of the gray-sided vole from the southwestern part of the island of Hokkaido to its northeastern part within the framework of a phenomenological model involving the relative length of summer and winter. In Hokkaido, as in other northern regions, both spring and fall is considered as short transition periods between the two main seasons — summer (the primary breeding season) and winter (the non-reproductive or secondary breeding season). We show that the geographic transition in dynamics may be understood as the combined consequence of different patterns of density-dependence during summer and winter, and geographically varying season lengths. Differences are shown to exist between summer and winter with respect to strength of density-dependence. Direct density-dependence, in particular, is stronger during winter than during summer. A model is presented to show how relative lengths of seasons can induce both stable and periodically fluctuating population dynamics. The results are compared and contrasted with what is otherwise known about the gradient in rodent dynamics in Fennoscandia.     

《本草纲目》与伊斯兰(回回)医药的关系

《本草纲目》中的不少“本草”是从西方的伊斯兰诸国传入中国的,伊斯兰民族的医学典籍中的例举及其诠释足可证明这个事实。     

南京市自主创新能力的现状分析

运用企业自主创新能力的评价指标体系,对南京市自主创新能力水平进行纵向和横向比较,可以比较好地把握其自主创新能力的现状。通过对南京市近四年自主创新能力指标的纵向比较,不难发现除了自主创新环境之外,南京市的自主创新资源、自主创新活动以及自主创新产出能力均有较大幅度的增长;通过将南京市与三大科技竞争力较强的城市自主创新能力指标进行横向比较,指出了南京市在自主创新能力上存在的突出问题。一是工业增加值率过低,二是研发经费过低。并在此基础上提出一系列对策和建议。对于提高南京自主创新能力水平,无疑具有重大的理论意义和现实意义。     

我国文化产业的梯级开发和利用初探

随着全球化的进一步扩张,一种全球文化消费的观念逐渐成形。世界各国相应加大对文化的保护和开发,物质文化与非物质文化遗产的保护和开发也提上政府的议事日程。适时将文化作为一种产业进行规范的开发和可持续利用,也是今后各级政府工作的重中之重。     

欠发达地区政府行为公共性弱化探析

公共性是政府的根本属性,它决定了政府必须将公共利益作为政府行为的首要原则,确保公共利益得到切实维护和实现。然而,由于各种主客观原因,目前欠发达地区政府行为表现出了利益化、法外化、低效化的不良特征,导致政府行为公共性弱化。本文讨论了欠发达地区政府行为公共性弱化的现实原因,并提出了规避欠发达地区政府行为公共性弱化的路径选择。     

卢甘国考

本文就宋代文献中经常出现的"卢甘国"这一名词进行考证,辨清了以往学界的误认,得出了卢甘国就是今青海省东南部黄河源头的古羌族部落的结论。     

人口较少民族发展道路探析——以鄂温克民族为例

本文以鄂温克族为例,探析了人口较少民族发展的道路,分析总结了人口较少民族发展的重要经验。