全文获取类型
收费全文 | 113篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 4篇 |
环保管理 | 22篇 |
综合类 | 31篇 |
基础理论 | 13篇 |
污染及防治 | 22篇 |
评价与监测 | 1篇 |
社会与环境 | 27篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 2篇 |
1985年 | 16篇 |
1984年 | 16篇 |
1983年 | 19篇 |
1982年 | 12篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 0 毫秒
31.
小流域地段景观生态设计研究——以大别山巴河上游地段为例 总被引:1,自引:0,他引:1
陈剑中 《长江流域资源与环境》1996,(1)
在实地调查研究的基础上,分析了巴河上游流域地段的景观结构功能与演替及流域治理存在的问题,切中流域生态环境变化的要害——水土流失问题。在区内景观带自然分异的基础上,进行了流域景观生态设计。 相似文献
32.
Kendall J. Bryant 《Journal of environmental psychology》1984,4(1):43-60
Two perspectives in the analysis of pointing and mapping tasks as the measure of representations of the large-scale environment are examined. These two perspectives are: (1) an individual difference approach; and (2) a cognitive representational approach. Convergence between methods assessing the same geographical/spatial knowledge is necessary as evidence for the existence of unified cognitive-spatial representations of the environment.Three sets of analyses interrelate performance on pointing and mapping tasks. In the first analysis, a confirmatory factor analytic model is applied to short tests of pointing and mapping accuracy to determine whether one or two factors are needed to account for covariation between the tests. In the second analysis, covariation among errors in pointing and mapping of specific locations is partitioned into general and specific method factors using the Schmid-Leiman procedure. In the third analysis, pointing errors for identical locations within the mapping and pointing tasks are directly compared on the basis of directional errors.The three analyses indicate that: (1) tests of pointing and mapping measure highly related abilities; (2) the targets used in pointing and mapping tasks are of differential importance in identifying general and specific method factors; and (3) there is little or no direct correspondence between directional errors made in pointing tasks and those occurring in mapping tasks for the same locations.When results of the three analyses are examined in relationship to criteria for convergence of pointing and mapping tasks, little evidence is found to suggest that directional errors in these tasks arise from a unified mental representation of the geographical environment. However, substantial predictable individual differences are apparent for both tasks. 相似文献
33.
The city canal of Colombo, an effluent canal running through the city, was monitored for its nitrogeneous species and toxic trace metal contents. The canal is the dumping ground for municipal garbage, human and animal excreta, organic waste matter, etc. However, nitrate content of the canal water remains low, indicating an incomplete nitrification process. Due to the existing pH and redox conditions, the nitrogen species are present in a chemically reduced form. Since the Pb, Cd, and Zn contents of the canal water are high, industrial contamination is obvious. The environmental impact of such a polluted canal is enhanced by the presence of a large number of drinking water wells in the vicinity of the canal. 相似文献
34.
Douglas W. Kuehl Elizabeth Durhan Brian Butterworth Darcy Linn 《Environment international》1984,10(1):45-49
Fish from 18 major watersheds near the Great Lakes were collected in 1979, 1980, or 1981, and analyzed by gas chromatography-mass spectrometry for polychlorinated planar organic chemical residues. Isomers of 36 different chemicals were identified by mass spectral data but not quantitated. The list includes isomers of chlorinated dibenzo-p-dioxins and dibenzofurans. 相似文献
35.
36.
The distribution of Nickel-63, Iron-59, Manganese-54 and Tin-113 in plasma was studied in rats which received single intravenous (i.v.) injection of aqueous solutions of their salts alone, and in rats which also received single intramuscular (im) injection of triethylene tetramine (TETA). TETA was extremely effective in reducing the plasma concentration of Nickel-63 followed by that of Iron-59, Manganese-54 and Tin-113. 相似文献
37.
38.
39.
明确濒危水鸟栖息地分布并加以保护对于维持水鸟物种多样性和提高湿地环境质量具有重要意义.自1980年以来京津冀地区水鸟数量出现较大波动,为了分析濒危水鸟潜在分布区域及其变化特征,借助GIS平台和MaxEnt模型,基于2015年濒危水鸟"出现点"信息,定量识别了影响京津冀地区濒危水鸟分布的主要驱动因素和贡献率,并预测了2050年RCP2.6、RCP4.5、RCP8.5(依次代表低、中、高3种CO2浓度排放模式)3种气候情景下濒危水鸟的潜在适宜区分布和保护空缺规律.结果表明:①京津冀地区濒危水鸟共有9种,东方白鹳、遗鸥和黑鹳3种濒危水鸟潜在适宜区面积较大.东方白鹳和遗鸥适宜区主要集中于环渤海湾沿岸和北京市中南部,黑鹳则主要集中于北京市南部房山区和东北部.②与2015年相比,2050年RCP2.6、RCP4.5和RCP8.5三种气候情景下濒危水鸟适宜区面积均较大,相应适宜区面积增幅依次为96.24%、103.94%和65.51%,适宜区空间分布上向西南和东北方向扩张.③国家自然保护区对濒危水鸟潜在适宜区和热点区的覆盖率较低,相较天津市,河北省和北京市对这两个区域的覆盖不足.④在京津冀地区尺度下,不同情景下保护区覆盖濒危水鸟适宜区比例依次为基准情景(1.26%)> RCP8.5情景(1.11%)> RCP2.6情景(0.70%)> RCP4.5情景(0.29%),保护区覆盖热点区比例依次为RCP4.5情景(0.83%)>基准情景(0.77%)> RCP8.5情景(0.08%)> RCP2.6情景(0).研究显示,以单个水鸟为单位分析濒危水鸟潜在适宜区分布格局,能够精准有效地揭示国家自然保护区对濒危水鸟的覆盖情况. 相似文献
40.
This study evaluated yield production and changes in the patterns of functional growth analysis parameters of greenhouse-grown soybeans exposed to low concentrations of ozone (O3). Plants were exposed over a 113-day interval for 341 h to four concentrations of O3 (2.0, 4.6, 7.0 and 9.7 pphm O3) on an intermittent basis. Destructive harvests were periodically taken from all treatments to monitor plant response and to provide the basis for growth analysis techniques. Relative to the ambient greenhouse air control treatment (2.0 pphm O3), 7.0 and 9.7 pphm O3 typically reduced plant biomass accumulation, leaf area and expansion, relative growth rate, unit leaf rate, seeds per plant (35% reduction), and other yield components; however, the growth and yield parameters of the 4.6 pphm O3 treatment were often stimulated. With this one exception, O3 reduced soybean vegetative growth and altered the pattern of biomass partitioning. As a consequence, the soybean yields were also reduced. 相似文献