排序方式: 共有5条查询结果,搜索用时 31 毫秒
1
1.
2.
Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined. 相似文献
3.
4.
人们在对岸线资源的并发利用过程中,总是比较难以协调保护和利用的矛盾,因此,协调好岸线资源的保护与利用的矛盾在海岸规划开发过程中十分重要。本文主要在前人已经取得的研究成果基础上,结合湛江市南三岛海岸线资源极其发展现状,分析了南三岛岸线的自然资源特征,并对其保护及开发利用进行初步的研究和探讨。 相似文献
5.
基于广深港客运专线东涌站的站场周边地区规划设计,通过分析该地区的功能定位、空间结构、交通组织、建筑高度、开发强度、开发空间等方面的问题,确定合理的发展模式及分期建设规划,同时也为我国高速铁路站点周边地区的建设积累经验。 相似文献
1