全文获取类型
收费全文 | 1683篇 |
免费 | 218篇 |
国内免费 | 164篇 |
专业分类
安全科学 | 307篇 |
废物处理 | 24篇 |
环保管理 | 375篇 |
综合类 | 701篇 |
基础理论 | 215篇 |
污染及防治 | 52篇 |
评价与监测 | 201篇 |
社会与环境 | 109篇 |
灾害及防治 | 81篇 |
出版年
2024年 | 4篇 |
2023年 | 32篇 |
2022年 | 63篇 |
2021年 | 89篇 |
2020年 | 64篇 |
2019年 | 68篇 |
2018年 | 55篇 |
2017年 | 94篇 |
2016年 | 116篇 |
2015年 | 67篇 |
2014年 | 93篇 |
2013年 | 111篇 |
2012年 | 116篇 |
2011年 | 129篇 |
2010年 | 89篇 |
2009年 | 106篇 |
2008年 | 66篇 |
2007年 | 123篇 |
2006年 | 90篇 |
2005年 | 68篇 |
2004年 | 49篇 |
2003年 | 51篇 |
2002年 | 46篇 |
2001年 | 35篇 |
2000年 | 41篇 |
1999年 | 24篇 |
1998年 | 24篇 |
1997年 | 26篇 |
1996年 | 17篇 |
1995年 | 10篇 |
1994年 | 14篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1971年 | 3篇 |
排序方式: 共有2065条查询结果,搜索用时 15 毫秒
911.
Ammonium nitrate is one of the most widespread contaminants related with the viability of natural amphibian populations. In this study we have evaluated in terms of mortality and total length the effects that a previous sublethal pulse to ammonium nitrate generates in Epidalea calamita. Experiments were divided in two phases. In the first one, tadpoles were exposed to two different treatments, with and without a low ammonium nitrate concentration (22 mg NH4NO3 L−1). The second phase consisted in static toxicity experiments from both origin treatments with five different nominal concentrations (0, 22, 45, 90 and 180 mg NH4NO3 L−1). Results showed that tadpoles that had experienced a previous sublethal exposure showed a negative effect on survival (57% of reduction in the LC50 value) and total length, throughout an increase in their sensitivity. These results could help us to understand the situation of amphibian populations inhabiting aquatic ecosystems exposed to discontinuous and variable pulses of pollutants. 相似文献
912.
He Jie Département d’économique GREDI Faculté d’administration Université de Sherbrooke boulevard de l’Univesité Sher-brooke QC JKR Canada 《中国人口.资源与环境(英文版)》2008,6(1):14-24
In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production function in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μ g/m^2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth. 相似文献
913.
Introduction
In this paper, we show that FARS data can be a comparable alternative to observational NOPUS data in estimating seat belt use in the United States once we correct for sample selection bias.Results
Based on assumptions of independence for seatbelt choice, we establish a lower and upper bound for seatbelt usage rates, and find that once we correct for sample selection bias, the seatbelt usage estimates from the corrected FARS emerge at least as a comparable alternative to NOPUS estimates.Impact on Industry
This implies that researchers can use corrected FARS to complement NOPUS, thus being able to utilize the rich cross-sectional details available in FARS data to analyze various relevant research questions. 相似文献914.
Areal FJ Touza J MacLeod A Dehnen-Schmutz K Perrings C Palmieri MG Spence NJ 《Journal of environmental management》2008,89(4):300-307
This paper analyses the cut flower market as an example of an invasion pathway along which species of non-indigenous plant pests can travel to reach new areas. The paper examines the probability of pest detection by assessing information on pest detection and detection effort associated with the import of cut flowers. We test the link between the probability of plant pest arrivals, as a precursor to potential invasion, and volume of traded flowers using count data regression models. The analysis is applied to the UK import of specific genera of cut flowers from Kenya between 1996 and 2004.There is a link between pest detection and the Genus of cut flower imported. Hence, pest detection efforts should focus on identifying and targeting those imported plants with a high risk of carrying pest species. For most of the plants studied, efforts allocated to inspection have a significant influence on the probability of pest detection. However, by better targeting inspection efforts, it is shown that plant inspection effort could be reduced without increasing the risk of pest entry. Similarly, for most of the plants analysed, an increase in volume traded will not necessarily lead to an increase in the number of pests entering the UK. For some species, such as Carthamus and Veronica, the volume of flowers traded has a significant and positive impact on the likelihood of pest detection. We conclude that analysis at the rank of plant Genus is important both to understand the effectiveness of plant pest detection efforts and consequently to manage the risk of introduction of non-indigenous species. 相似文献
915.
Top-down法计算中国五氯酚钠消费分布 总被引:2,自引:0,他引:2
为履行<关于持久性有机污染物(POPs)的斯德哥尔摩公约>,中国将逐渐淘汰POPs的生产和使用,环境介质中POPs浓度监测和处置是履约工作的重要部分,而其消费分布的研究可以为监测和模型计算找出重点区域.采用Top-down法,根据当年全国的五氯酚钠消费,以药物灭螺面积、钉螺面积、血吸虫病流行村数等为替代数据,计算了各省份的五氯酚钠消费分布,并进一步计算出省内各市级地区的五氯酚钠消费分布.从2003年的计算结果来看,五氯酚钠消费最大的是湖北省和湖南省,两省五氯酚钠消费占到全国总消费的72.62%.最主要的地区是湖北省荆州市和湖南省岳阳市、常德市、益阳市,分别占全国总消费的15.25%、12.78%、11.72%、9.89%,总和占到全国总消费的49.64%,上述地区将成为今后研究和监测的重点区域. 相似文献
916.
Theodore E. Endreny Gregory D. Jennings 《Journal of the American Water Resources Association》1999,35(2):363-377
ABSTRACT: Recent developments in water quality monitoring have generated interest in combining non-probability and probability data to improve water quality assessment. The Interagency Task Force on Water Quality Monitoring has taken the lead in exploring data combination possibilities. In this paper we take a developed statistical algorithm for combining the two data types and present an efficient process for implementing the desired data augmentation. In a case study simulated Environmental Protection Agency (EPA) Environmental Monitoring and Assessment Program (EMAP) probability data are combined with auxiliary monitoring station data. Auxiliary stations were identified on the STORET water quality database. The sampling frame is constructed using ARC/INFO and EPA's Reach File-3 (RF3) hydrography data. The procedures for locating auxiliary stations, constructing an EMAP-SWS sampling frame, simulating pollutant exposure, and combining EMAP and auxiliary stations were developed as a decision support system (DSS). In the case study with EMAP, the DSS was used to quantify the expected increases in estimate precision. The benefit of using auxiliary stations in EMAP estimates was measured as the decrease in standard error of the estimate. 相似文献
917.
地表水自动监测网数据自动审核的创新与实践 总被引:1,自引:0,他引:1
在地表水质量自动监测网络的质量保证管理中,山东省省、市两级监控中心使用计算机数据审核系统对监测数据进行实时监控和质量控制,创新地实现了对监测数据有效性的自动判别、监测网的运行情况自动评价等自动化质控措施。 相似文献
918.
This paper analyzes the impacts of urbanization and unemployment rate on China’s divorce rate with the panel data of 31 Chinese provinces from 2000 to 2011. The study manifests as follows. First, the significant influence of urbanization cannot be observed on the rising breakdown since the latter is not the inevitable result of the former. In the second place, unemployment rate has a significant negative influence on divorce rate, namely, with the former increasing, the latter will decrease, which echoes the perspective of divorce cost. And finally, this paper also finds positive effects of per capita fixed investment, old-age dependency rate, average household size, the proportion of floating population and population density, and negative correlation of average education attainment on divorce rate. 相似文献
919.
He Jie 《中国人口.资源与环境(英文版)》2013,11(1):14-24
Abstract In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production function in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μg/m2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth. 相似文献
920.
Matthias Brueggmann Matthias Roetting Holger Luczak 《International journal of occupational safety and ergonomics》2013,19(4):387-401
A comparison of international literature in occupational safety and health (OSH) research over the years from 1980 to 1998 was conducted. The comparison is based on the different languages of the over 35,000 articles, which were collected from different databases. The distribution of languages in the analyzed data has to be considered carefully with respect to the original purpose of the data collection and the specific role of the international publication language, English. The comparison shows that in several aspects OSH research does not differ in different publication languages. In some methodological aspects, and in specific objects of research, differences between articles published in different languages can be found. 相似文献