全文获取类型
收费全文 | 25276篇 |
免费 | 213篇 |
国内免费 | 191篇 |
专业分类
安全科学 | 583篇 |
废物处理 | 1051篇 |
环保管理 | 3143篇 |
综合类 | 5575篇 |
基础理论 | 5778篇 |
环境理论 | 9篇 |
污染及防治 | 6410篇 |
评价与监测 | 1571篇 |
社会与环境 | 1461篇 |
灾害及防治 | 99篇 |
出版年
2022年 | 187篇 |
2021年 | 200篇 |
2019年 | 164篇 |
2018年 | 327篇 |
2017年 | 297篇 |
2016年 | 499篇 |
2015年 | 381篇 |
2014年 | 560篇 |
2013年 | 1792篇 |
2012年 | 660篇 |
2011年 | 956篇 |
2010年 | 771篇 |
2009年 | 868篇 |
2008年 | 986篇 |
2007年 | 1081篇 |
2006年 | 958篇 |
2005年 | 789篇 |
2004年 | 825篇 |
2003年 | 812篇 |
2002年 | 752篇 |
2001年 | 952篇 |
2000年 | 650篇 |
1999年 | 453篇 |
1998年 | 283篇 |
1997年 | 310篇 |
1996年 | 315篇 |
1995年 | 358篇 |
1994年 | 352篇 |
1993年 | 319篇 |
1992年 | 300篇 |
1991年 | 335篇 |
1990年 | 299篇 |
1989年 | 273篇 |
1988年 | 275篇 |
1987年 | 248篇 |
1986年 | 224篇 |
1985年 | 229篇 |
1984年 | 280篇 |
1983年 | 271篇 |
1982年 | 279篇 |
1981年 | 227篇 |
1980年 | 210篇 |
1979年 | 208篇 |
1978年 | 210篇 |
1977年 | 179篇 |
1976年 | 167篇 |
1975年 | 174篇 |
1974年 | 197篇 |
1973年 | 151篇 |
1967年 | 158篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
962.
963.
964.
Luis H. P. Garbossa Robson V. Souza Carlos J. A. Campos Argeu Vanz Luiz F. N. Vianna Guilherme S. Rupp 《Environmental monitoring and assessment》2017,189(1):27
Thermotolerant coliform (TC) loadings were quantified for 49 catchments draining into the North and South Bays of Santa Catarina (SC, southeastern Brazil), an area known for its tourism and aquaculture. TC loadings were calculated based on flow measurements taken in 26 rivers. TC concentrations ere quantified based on surface water samples collected at 49 catchment outlets in 2012 and 2013. Median TC loads ranged from 3.7 × 103 to 6.8 × 108 MPN s?1. TC loadings in the catchments increased in proportion to increases in resident human population, population density and percentage of urbanised area. Catchments with more than 60% of area covered by wastewater collection and treatment systems had higher TC loads per person than catchments with less than 25%. Based on the study catchments, these results indicate that current sewerage infrastructure is ineffective in reducing contamination of faecal origin to surface waters. These findings have important implications for the management of microbiological health hazards in bathing, recreational and shellfish aquaculture waters in the North and South Bays of Santa Catarina Island. 相似文献
965.
J. F. Jasonsmith B. C. T. Macdonald I. White 《Environmental monitoring and assessment》2017,189(4):188
Wybong Creek discharges salts into the agriculturally and industrially important Hunter River in New South Wales, Australia. Abrupt increases in salinity occur periodically in the mid-Wybong Creek catchment. In order to understand the processes which cause these abrupt increases, changes in surface and groundwater were investigated. It is shown that salinity increases can be attributed to highly discrete groundwater discharge directly into the river from below. Hourly electrical conductivity data measured in the river showed regular, diurnal electrical conductivity fluctuations of up to 350 μS cm?1. These fluctuations could not be attributed to barometric pressure, temperature, or evapotranspiration. Instead, a similar periodicity in surface water electrical conductivity and groundwater height in nearby groundwater wells was found. Fluctuations were of similar periodicity to the orthotides which cause fluctuations in surface water height and are induced by Earth tides. The geology in the mid-catchment area indicates conditions are optimal for Earth tides to impact groundwater. The reporting of orthotidal changes in water chemistry in this article is believed to be the first of its kind in the scientific literature, with the large fluctuations noted having important implications for water monitoring and management in the catchment. Further research investigating Earth-tide-induced phases of groundwater heights will better constrain the relationships between surface water chemistry and groundwater height. 相似文献
966.
This study investigates land cover change near the abandoned Pine Point Mine in Canada’s Northwest Territories. Industrial mineral development transforms local environments, and the effects of such disturbances are often long-lasting, particularly in subarctic, boreal environments where vegetation conversion can take decades. Located in the Boreal Plains Ecozone, the Pine Point Mine was an extensive open pit operation that underwent little reclamation when it shut down in 1988. We apply remote sensing and landscape ecology methods to quantify land cover change in the 20 years following the mine’s closure. Using a time series of near-anniversary Landsat images, we performed a supervised classification to differentiate seven land cover classes. We used raster algebra and landscape metrics to track changes in land cover composition and configuration in the 20 years since the mine shut down. We compared our results with a site in Wood Buffalo National Park that was never subjected to extensive anthropogenic disturbance. This space-for-time substitution provided an analog for how the ecosystem in the Pine Point region might have developed in the absence of industrial mineral development. We found that the dense conifer class was dominant in the park and exhibited larger and more contiguous patches than at the mine site. Bare land at the mine site showed little conversion through time. While the combination of raster algebra and landscape metrics allowed us to track broad changes in land cover composition and configuration, improved access to affordable, high-resolution imagery is necessary to effectively monitor land cover dynamics at abandoned mines. 相似文献
967.
J. Franzaring G. E. Mbaka T. F. Ambebe J. N. Nkengafac S. Schlosser A. Fangmeier 《Environmental monitoring and assessment》2017,189(4):186
The growing population number and traffic loads, increasing environmental pressures, agricultural intensification, and the establishment of Mount Cameroon National Park demand farsighted environmental management in the region and the definition of a favorable ecological status. Since plants grow in the interface between soils and the atmosphere they can be used as passive biomonitors for the environmental quality. At the same time, the accumulation of nutrients and pollutants in crops is linked to human health, so that foliar elemental levels can be used as an integrative measure for environmental pollution and impact assessment. In the present study, we collected leaf samples of plantain, cassava, cocoyam, and maize on 28 sites at the southern flanks of Mt. Cameroon and determined 20 chemical elements. Air pollution in the study area comes from biomass and waste burning mainly, but emissions from traffic and a large refinery were believed to also play a significant role. However, spatial patterns in foliar elemental concentrations reflected the geochemistry rather than specific sources of pollution. Significant differences in foliar metal and nutrient levels were observed between the four species, indicating a different demand and uptake of specific elements. The results were compared to published data on nutrient concentrations in the tested species and the so-called reference plant. The data can be used as a baseline for future studies in plant nutrition and the environmental monitoring in inner tropical regions where these crops are grown. 相似文献
968.
H. W. Zhang Y. Q. Sun Y. Li X. D. Zhou X. Z. Tang P. Yi A. Murad S. Hussein D. Alshamsi A. Aldahan Z. B. Yu X. G. Chen V. d. P. MUGWANEZA 《Environmental monitoring and assessment》2017,189(8):411
Assessment of groundwater quality plays a significant role in the utilization of the scarce water resources globally and especially in arid regions. The increasing abstraction together with man-made contamination and seawater intrusion have strongly affected groundwater quality in the Arabia Peninsula, exemplified by the investigation given here from the United Arab Emirates, where the groundwater is seldom reviewed and assessed. In the aim of assessing current groundwater quality, we here present a comparison of chemical data linked to aquifers types. The results reveal that most of the investigated groundwater is not suitable for drinking, household, and agricultural purposes following the WHO permissible limits. Aquifer composition and climate have vital control on the water quality, with the carbonate aquifers contain the least potable water compared to the ophiolites and Quaternary clastics. Seawater intrusion along coastal regions has deteriorated the water quality and the phenomenon may become more intensive with future warming climate and rising sea level. 相似文献
969.
Human population growth in coastal areas continues to threaten estuarine ecosystems and resources. Populations of Crassostrea virginica have declined across the USA due to water quality degradation, disease pressure, alteration of habitat, and other changes related to anthropogenic impacts. Metals that may be present in estuarine habitats can bioaccumulate in oysters, with potential consequences to the health of oysters and humans consumers. This study (1) evaluated the occurrence and relationships of metal concentrations in oyster tissue versus estuarine sediments, (2) examined oyster tissue concentrations in relation to state water quality designations, and (3) evaluated the potential risk for humans from oyster consumption related to metal concentrations from harvestable waters. Results indicated metal concentrations in sediments and oysters along coastal South Carolina remain low compared to other areas and that concentrations in oyster tissue and adjacent sediments were not highly correlated with each other. However, high concentrations of some metals occurred in oysters sampled from areas designated as Approved for Harvesting. This is important because most harvest area designation systems rely on regular bacterial monitoring when evaluating the safety of consumption. Others safety measurements may be necessary as part of routine monitoring. 相似文献
970.
I. Panagiotoulias F. Botsou H. Kaberi A. P. Karageorgis M. Scoullos 《Environmental monitoring and assessment》2017,189(11):598
In order to document the impact of Best Available Techniques (BAT) and implementation of regulation on the improvement of the coastal marine environment state, we examined the case of a representative steel mill located at the Gulf of Elefsis (Greece). The evaluation of metal pollution was based on the analysis of major and trace elements, organic carbon, magnetic properties, and sediment accumulation rates, in sediment cores obtained from the vicinity of the plant. The analytical data are discussed in relation to steel production, changes of production routes, and adoption of BAT introduced in order to fulfill EU and national legislation. The results show that the input of pollutants to sediments and the degree of contamination were reduced by approximately 40–70% in the decade 2003–2015 in comparison to the periods of high discharges (1963–2002), whereas the toxicity risks from “high-to-extremely high” were reduced to “medium-to-high.” 相似文献