Genetic amniocentesis in multiple gestations

Thirty-one genetic amniocenteses involving multiple gestations were performed in the genetics unit between 1976 and 1982. Three sets of triplets were included. Precise locations of the sacs were determined using real-time ultrasonography and successful sampling of all sacs was accomplished. Spontaneous abortions occurred in two normal twins and one normal triplet gestation. Two therapeutic abortions were performed for fetal abnormalities. Two cases of discordance for trisomy 21 (one twin and one triplet) were allowed to continue; the twin case terminated at 25 weeks' gestation with neonatal deaths and the triplets are alive and well.     

基塘系统可持续发展现状、问题及对策研究

珠江三角洲基塘生态系统是一种独特的人工生态系统，也是可持续农业的一种类型。本文分析了在经济高速发展的条件下，基塘生态系统的特点、现状及可持续发展中存在的问题，并针对性地提出对策和建议。     

环境影响评价与环境管理体系关系初探

分析环境影响评价和环境管理体系之间的差异性及内在相关性特征，提出在保护环境工作中将两者有机结合的重要意义，阐明了环境保护工作新的思路。     

Nutrient budgets: sustainability assessment of rainfed lowland rice-based systems in northeast Thailand

In northeast Thailand, the sustainability of rainfed lowland rice-based systems, the dominant land-use system (LUS) in the region, is a concern for the welfare of the population in this relatively poor region. Poor soil fertility and low inputs are seen as major causes of this lack of sustainability. In this context, the assessment of nutrient budgets is seen as a powerful tool for the assessment of critical components of the sustainability of this particular LUS. Biophysical, socioeconomic, and management-related data on the farming systems were collected for 30 farms in Ubon Ratchathani Province, northeast Thailand. A relational database system (RDBS) was developed to manage and analyze the data. The RDBS includes a calculation procedure for the semi-automatic generation of partial nutrient balances. Partial nutrient balances are good indicators for some critical components of sustainability, and important for decision support on soil fertility management when considered with the additional factors that are required for a full nutrient balance.For the rice-based systems of 30 farms, mean partial balances were 12 kg N ha⁻¹, 8 kg P ha⁻¹, and 7 kg K ha⁻¹ per year. Large variations in partial N, P, and K balances exist among different farms and, even more so, for different land utilization types (LUTs). The LUTs are distinct cropping system–management combinations that occur down to the subfield level. Many of the partial balances assessed were negative.Farmers manage nutrients for similar parcels of land in very different ways. This results in the observed large variation in partial nutrient balances, even for the same type of land use within the same farm. These results confirm the high inter-farm and intra-farm variability for partial balances of N, P, and K of several preliminary studies. Farmer interviews and field surveys revealed that different socioeconomic factors appear to be related with inter- and intra-farm variability in nutrient budgets. In addition, the socioeconomic component of the case study revealed that diversification of income sources, particularly off-farm employment, had a larger impact on household income than rice production. Furthermore, while many less well-off households had a greater reliance on rice production, many farms with high off-farm and non-rice farm income had a higher total production of rice.The nutrient balance approach, starting with partial nutrient balances, may become an important component of a dynamic and site-specific decision support tool (DST) for nutrient management, and a relational database of the form used in this study may become a key element.     

地铁型材模具的探讨

介绍了大型铝型材的特点 ,大型铝型材模具的设计 ,分流比的选择 ,分流孔位置的布置 ,芯头颈部的选择 ,工作带的确定以及加工中的注意事项     

涂料印花废水污染治理技术

分析了涂料直接印花废水污染物成分和理化性质，提出了该废水的治理措施。     

经济增长的生态环境代价及思考

以可持续发展理论为指导，分析了重庆市经济增长的生态环境代价，对目前的经济增长方式作了深刻反思、据测算、重庆市仅生态破坏、大气污染、水污染造成的经济损失就占全市ＧＤＰ的１６．１％。要改变不合理的发展方式，必须落实可持续发展的发展战略、转变经济增长方式，增加生态环境保护投入，加强资源与环境核算和环境法制工作。     

蒙山茶业发展中的生态环境问题与对策刍议

分析了蒙山茶业生态环境特征，指出目前传统茶区存在的弊病，提出在蒙山建立生态茶区的重要性及其具体措施。     

建筑与环境

引述了“可持续发展”的战略原则 ,对建筑设计中采用环保的设计方法进行了探讨和论述。列举了建筑与环境、建筑节能新技术的应用、循环再生建筑、健康的室内环境以及建筑与历史、地域、人文环境的关系。并介绍了国外建筑环保材料的应用与发展趋势     

关于区域可持续发展的思考与实践

以特大城市中心城区——上海市徐汇区为对象,探讨了实施区域可持续发展的基础和途径,提出区域可持续发展要注重塑造特色品牌,以科技产业化、城市环境建设、社区管理等方面的优先项目为载体,加以切实推进。