全文获取类型
收费全文 | 595篇 |
免费 | 74篇 |
国内免费 | 110篇 |
专业分类
安全科学 | 170篇 |
废物处理 | 37篇 |
环保管理 | 49篇 |
综合类 | 279篇 |
基础理论 | 80篇 |
环境理论 | 1篇 |
污染及防治 | 72篇 |
评价与监测 | 41篇 |
社会与环境 | 38篇 |
灾害及防治 | 12篇 |
出版年
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 21篇 |
2019年 | 23篇 |
2018年 | 21篇 |
2017年 | 25篇 |
2016年 | 19篇 |
2015年 | 33篇 |
2014年 | 30篇 |
2013年 | 38篇 |
2012年 | 47篇 |
2011年 | 47篇 |
2010年 | 24篇 |
2009年 | 41篇 |
2008年 | 25篇 |
2007年 | 39篇 |
2006年 | 33篇 |
2005年 | 29篇 |
2004年 | 16篇 |
2003年 | 27篇 |
2002年 | 32篇 |
2001年 | 23篇 |
2000年 | 26篇 |
1999年 | 19篇 |
1998年 | 19篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有779条查询结果,搜索用时 15 毫秒
91.
92.
通过对秦山核电站运行前后相隔近7 a 的工程区邻近海域四季度月生物与非生物环境生态各要素的两次调查分析,进行了Ⅰ期工程运行以来海域生态环境及水质状况的影响评价。结果认为,秦山海域具典型强潮河口湾生态特征,营养盐丰富,而生产力低下。潮汐、径流和湾外海水入侵是导致海洋环境要素季节和年际变化并直接影响海洋生物结构的主要因子。水体富营养化指数上升是沿岸工业和生活污水大量排放的结果。核电站运行中冷却水的热排放由于杭州湾特殊的海底地形和强潮混合的水体环境对附近水域的热升温效应不明显。秦山Ⅰ期工程运行以来对海域生态环境和水质变化未见明显影响 相似文献
93.
Zhang Qide Wang Yuxi Yu Shuqing Song Liming Liu Xianwan Li Changzhi Lin Hejie 《环境科学学报(英文版)》1989,1(1):73-84
The authors seek, through tests on simulated sand samples in a wind tunnel and analysis of minerals combination and trace elements, to discover the environmental implications of flying-up, falling-down and concentration variation as a function of natural wind speed and direction, distance of movement, range and extent of influence on the atmospheric environment, of micro-granular components on the ground surface in the Keerqin desert area in northwest Liaoning Province of China. 相似文献
94.
95.
96.
应用改进密切值法进行地表水环境综合评价 总被引:1,自引:0,他引:1
针对密切值法应用中的实际问题,引入目标差值率和虚拟优点、劣点的概念,对密切值法进行了改进.将改进后的密切值法应用于地表水环境综合评价中,经实例分析表明,该方法概念清晰、计算简便实用,且从评价结果可获许多潜在的信息,是开展地表水流域水环境综合评价的一种有效的方法. 相似文献
97.
This study investigated the floc aggregation, average floc size, floc size variance and floc growth velocity when ferric chloride (FeCl3) and polyferric chloride (PFC) were used to treat the simulated water samples. The factors including coagulant dose, ionic strength and solution pH, which affect the floc aggregation, were studied. Experiments were carried out in a bench-scale reactor using photometric dispersion analyzer ( PDA). Results showed that there were great differences between the floc aggregation of PFC and FeCl3. The average floc size and fioc growth velocity of PFC were much larger than those of FeCl3. Compared with FeCl3, PFC gave a better coagulation performance in wider range of pH, dosage and ionic strength. It was also found that the coagulation efficiency of PFC did not depend on average floc size but on floc growth velocity. 相似文献
98.
ABSTRACT: A simple simulator was constructed, calibrated, programmed and used in management studies of a hydraulic system containing two pumping stations in series, connected by canals and reservoirs. The features of the model, its calibration and use are described, and comparisons between measured and computed hydraulic behavior are presented. 相似文献
99.
A. V. Il’inykh 《Russian Journal of Ecology》2005,36(3):200-204
The impact of the nuclear polyhedrosis virus on the population dynamics of the gypsy moth Lymantria dispar L. has been studied. The results have shown that polyhedrosis morbidity in the western Siberian population of the insect is relatively low, compared to that reported for North American and European populations. A possible cause of this situation is found in the high migration activity of moths in the Asian L. dispar populations, which allows the virus load on the biotope to remain relatively stable and insufficient for the initiation of mass viral diseases during population outbreaks.__________Translated from Ekologiya, No. 3, 2005, pp. 222–226.Original Russian Text Copyright © 2005 by Ilinykh. 相似文献
100.
D. Wendum 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):6149
For operational or research purposes (dispersion computations of radioactive effluents during nuclear emergency situations, simulations of chemical pollution in the vicinity of thermal power plants), different models of passive dispersion in the atmosphere have been developed at the Environment Department of EDF’s R and D Division. This report presents the comparison of the performances of three such models: DIFTRA (lagrangian puff model, with operational goal), DIFEUL (three dimensional eulerian) and DIFPAR (Monte Carlo particle model) for the simulation of the first ETEX release, an international tracer campaign during which a passive tracer cloud has been followed over Europe. The results obtained in this study give model vs. experience differences of the same order as the model vs. experience differences observed during an international model comparison experiment using data of the Chernobyl release, the ATMES exercise. In addition to the standard statistical scores used in the evaluation of the performances of the transport models two asymmetric scores (in contradistinction with the Figure of Merit in Space) are proposed: “efficiency” and “power”. Their aim is to separate the two manners in which a model may be wrong: by predicting presence of pollutant while none is measured or conversely predicting absence when pollutant is actually detected. 相似文献