On the move: explaining migration patterns in Estonia during the transition period

This paper attempts to explore the migration patterns during the transition period in Estonia. A structuration approach was used to analyze data from the Estonian Statistical Office collected in 1997. Findings show that for migration between urban and rural areas, work-related reasons have been the most important motivating factor in urban growth during the transition period. Also considered are the family and education. In relation to sociodemographic structure of the population, men cite work, while women count family-related reasons, as the main motive for migrating. As to nonregistration, the most significant reason relates to issues of ownership. Because migrants are living in rented housing, it is not possible for them to register even if they desire to do so. Other reasons include "temporary", associated with study and work; "juridical", bureaucratic matters; and "multiple places of residence". This analysis, however, is incomplete because the attitudes and patterns of behavior have only partially or perfunctorily been related to the dramatic changes that have occurred in Estonian society. Proper statistical data are needed to help examine trends at a more disaggregated spatial level.     

Offshore experiments on styrene spillage in marine waters for risk assessment

Within the context of risk evaluation of chemical spillages into the marine environment, this paper reports on an offshore experiment to study the behaviour of styrene spilled into sea under natural conditions and discusses theoretical approaches. Floating structures were used to enclose the spillage and the gaseous cloud formation, and dissolution processes were in situ monitored. The identification of spill risks for man and marine environment through GESAMP's hazard profile is described for styrene: Styrene is rated as a chemical with a significant health hazard that will float but also evaporate. However, monitoring of the water column in the experiments showed that the concentration of styrene in water during the first hour represents 50% of the product spilled. For the potentially exposed public, the GESAMP hazard rating recommends the closure of beaches and evacuation. The risk assessment developed from experimental data confirms this safety advice.     

地理科学与农业发展中的若干综合问题

现在苏联地理学家参加的农业发展的研究工作有下列重要课题:从土地利用观点研究土地资源(分类、制图和土地的经济评价),农业现状的地域研究(类型、区划)和合理农业地域组织的论证(短期和长期预测)。从农业土地利用观点研究土地资源对环境地域综合体的研究,即土地类型学的发展,在过去是农业生产实践的需要,在将来也会继续保持其重要地位。     

关于城市生态地质环境的研究

研究生态地质环境要把人类置于中心地位,而城市又是人类最集中的生产和生活活动的聚集区.未来世界都市化已成为主导思潮,半个世纪前全球30%的人口住城镇,现在接近50%,2015年将达到2/3.城市人口的增长比乡村快2.5倍.因此研究人类生态地质环境要先从城市生态地质环境开始.     

认知冲突下一轮复习的深度学习与知识建构 ——以"三角洲堆积地貌"为例

认知冲突是认知发展过程中,学习者原有认知结构与现实情境之间的冲突或矛盾,是已有的知识经验与新知识不一致而暂时心理失衡的一种认知状态。在一轮复习中,很多学生囿于经验的认知,常会在试题或者情境中产生认知冲突,陷入迷茫和混乱的状态。究其原因,大多是真实情境中的认知冲突没有得到有效的解决。因此,本文以“三角洲堆积地貌”为例,通过深入和切换课堂情境,诱发一系列认知冲突,让学生在“经验—个体—集体”的认知冲突过程中,实现一轮复习的深度学习与知识建构,以期在一轮备考中发挥作用。     

Integrating GB and US census microdata for studying the impact of family migration on partnered women's labour market status

This paper investigates the problems in integrating different data sets for social science research. A cross-national analysis of the effects of family migration on labor market participation rates for female partners was used as an example to concretize these problems. The data used in the cross national analysis came from the 1991 British Census Sample of Anonymised Records and the 1990 United States Public Use Microdata Sample. The problems addressed were the following: data collection; manipulation and reliability; question type and definition; and measurement of individual and family variables. As part of the analysis, some empirical findings were also presented. Significant overall differences between the US and Great Britain (GB) samples were observed, particularly concerning graduate qualifications, marital and employment status, and ethnic group. There were higher numbers of married partners and full-time workers in the US sample, while female partners undertaking part-time employment were greater in GB. Furthermore, the US sample had more couples with a female graduate as compared with the GB sample who had a higher proportion of nongraduate couples. Finally, this paper recognized the importance of cross- national research in the evaluation of national ideological and institutional structures.     

空间扩散分析方法探讨

区域经济学指出:空间元素并不是以等同的,均匀的形式向周围地区扩散。通过分析区域内经济现象的空间扩散过程,我们可以发现:这种扩散过程是以某种特定的形式,而不是以随机的形式进行的,整个扩散过程是通过区域内人流、物流、信息流以及资金流来实现的。本文将通过经济元素的空间扩散过程的分析,介绍分析空间扩散形式的一种新的方法——空间倾向曲面。某一区域范围内,总有一点收入水准比周围地区高,并依次向周围地区递减。     

新疆尼勒克县喀英迪地区铅锌矿地质特征及成因

喀英迪铅锌矿主要产于早石炭世阿克沙克组及其与晚奥陶世呼独克达坂组的接触带上。通过普查工作共圈定15个铅锌矿体。其中主要矿体4个,Ⅰ-4矿体处于晚奥陶世呼独克达坂组灰岩与早石炭世阿克沙克组的不整合接触面上及其两侧,工程控制总长度为523m,最大斜深100m。倾向70°～100°,倾角一般20°～50°,连续性较好。该矿体铅单工程厚0.86～5.64m,平均2.86m,厚度变化系数为70.57%;锌单工程厚0.80～5.64m,平均1.81m,厚度变化系数为93.97%,属于变化较稳定型矿体。铅单工程品位0.62%～16.47%,平均4.53%,品位变化系数114.34%;锌单工程品位0.53%～12.37%,平均3.78%,品位变化系数57.47%。属于有用组分分布较均匀型矿体。通过对矿床地质特征的研究,认为该矿床属沉积岩容矿的、层控的、构造控制非岩浆型低温热液矿床。     

利用H/V谱比法辨识场址非线性反应(英文)

The horizontal-to-vertical spectral ratio has become popular in studies of the site effect and the determination of the predominant period of a site.