全文获取类型
收费全文 | 4960篇 |
免费 | 87篇 |
国内免费 | 503篇 |
专业分类
安全科学 | 163篇 |
废物处理 | 272篇 |
环保管理 | 467篇 |
综合类 | 1190篇 |
基础理论 | 977篇 |
环境理论 | 5篇 |
污染及防治 | 1690篇 |
评价与监测 | 414篇 |
社会与环境 | 308篇 |
灾害及防治 | 64篇 |
出版年
2024年 | 5篇 |
2023年 | 53篇 |
2022年 | 159篇 |
2021年 | 162篇 |
2020年 | 90篇 |
2019年 | 105篇 |
2018年 | 146篇 |
2017年 | 171篇 |
2016年 | 230篇 |
2015年 | 220篇 |
2014年 | 284篇 |
2013年 | 402篇 |
2012年 | 318篇 |
2011年 | 339篇 |
2010年 | 243篇 |
2009年 | 228篇 |
2008年 | 301篇 |
2007年 | 253篇 |
2006年 | 206篇 |
2005年 | 209篇 |
2004年 | 244篇 |
2003年 | 225篇 |
2002年 | 181篇 |
2001年 | 127篇 |
2000年 | 67篇 |
1999年 | 72篇 |
1998年 | 49篇 |
1997年 | 53篇 |
1996年 | 48篇 |
1995年 | 44篇 |
1994年 | 37篇 |
1993年 | 26篇 |
1992年 | 26篇 |
1991年 | 29篇 |
1990年 | 17篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 14篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1979年 | 8篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1966年 | 4篇 |
1964年 | 5篇 |
1958年 | 3篇 |
排序方式: 共有5550条查询结果,搜索用时 171 毫秒
961.
Public concern over the possibility of migration of stored CO2 to the surface with resulting damage to vegetation or hazard to humans and animals is a matter which will need to be addressed to be able to satisfy likely regulatory requirements for onshore CO2 storage in a number of jurisdictions. While soil CO2 concentration is readily measured continuously and in situ with current technology, the measurement of CO2 flux at depths below the soil A horizon may be a more sensitive and meaningful technique for early detection of a near surface CO2 plume. We describe a system for the continuous measurement of soil CO2 flux at a depth of approximately 1.3 m and present results from three instruments deployed at the Otway Basin Pilot Project in Victoria, Australia and one development system deployed at Sutton, near the Australian Capital Canberra. 相似文献
962.
The phylogeography of two sympatric Magellanic limpets of the genus Nacella was studied. The historical and contemporary processes underlying their intraspecific patterns in Argentina were inferred using the mitochondrial cytochrome oxidase I gene. Results indicate different evolutionary histories in the two species. A recent geographic and demographic expansion ~11,000?years ago, with absence of current genetic structuring, is proposed for Nacella magellanica. In contrast, the phylogeographic pattern showed noticeable phylogenetic and geographic discontinuities in Nacella deaurata; slow continuous population size growth with current low levels of gene flow among its populations was also observed, indicating demographic equilibrium. The beginning of divergence between these closely related limpets was estimated at about 270,000?years ago with very little or none gene flow occurring after their splitting. These contrasting historic patterns could be related to distinctive responses to climate changes associated with Pleistocene glaciations, as a result of differences in their ecological traits. 相似文献
963.
In this paper, we argue that understanding marine ecosystem functioning requires a thorough appreciation of the role of intraguild
predation to system dynamics. The theoretical predictions of intraguild predation models might explain some of the community
features observed in marine ecosystems such as low diversity in upwelling and productive systems and species alternation in
response to moderate external forcing. Finally, we argue that an ecosystem approach to fisheries requires that the size–structure
of fish populations should be taken into account and that it is extremely important to account for the predators of early
stages (eggs and larvae) to gain a thorough understanding of the key interactions between species. 相似文献
964.
965.
Flávia Noronha Dutra Ribeiro Jacyra Soares Amauri Pereira de Oliveira 《Environmental Fluid Mechanics》2011,11(6):551-572
This work investigates the capability of an oceanic numerical model dynamic and thermodynamically coupled to a three-dimensional
mesoscale atmospheric numerical model to simulate the basic features of the air–sea interaction in the coastal upwelling area
of Cabo Frio (RJ, Brazil). The upwelling/downwelling regime is an important feature in the oceanic circulation of Cabo Frio
and determines the sustainability of local ecosystems. This regime is predominantly driven by the atmospheric circulation
and is well documented, being suitable to be used as test reference for atmospheric and oceanic coupled and uncoupled models.
The oceanic boundary conditions, coastline shape and coupling effect have been tested. The uncoupled oceanic model forced
by a NE (SW) wind field generates a realistic upwelling (downwelling) phenomenon regardless of the proximity of the lateral
boundary and how realistic is the shape of the coastline. The atmospheric-oceanic coupled model generates an upwelling location
and intensity similar to the uncoupled simulation, but the upwelling is gradually enhanced by the sea-breeze circulation.
It also generates vertical profiles of mixing ratio that compare better to the observations than the uncoupled simulation
and air potential temperature and wind vertical profiles that represent particular features of the atmospheric circulation
at Cabo Frio. 相似文献
966.
Polycyclic aromatic hydrocarbons in effluents from wastewater treatment plants and receiving streams in Tianjin, China 总被引:1,自引:0,他引:1
Weixiao Qi Huijuan Liu Jiuhui Qu Chengzhi Hu Huachun Lan Michael Berg Huimin Ren Wei Xu 《Environmental monitoring and assessment》2011,177(1-4):467-480
Surface water, suspended particulate matter, pore water, and sediment samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) in Yongding New River, South Drainage Canal and North Drainage Canal, which receive most of wastewater from industrial city of Tianjin. PAH concentrations in effluent samples of wastewater treatment plants (WTP) discharging into the South Drainage Canal and North Drainage Canal were quantified for the first time. The results showed that the discharge of the WTPs recently only contributed to the PAH contamination in the canals near the outlets of the WTPs. PAH levels in sediments of the streams were greatly higher than those in soils by riverbank probably due to receiving large amounts of untreated wastewater. Unusually high benz[a] anthracene concentration strongly influenced the seasonal and spatial variation of total PAH concentrations in South Drainage Canal. Paired samples t test of ??Nap, Fl, Phe, Fluo and ??Nap, Phe, Fluo, Chry concentrations, which were dominant components in the air samples from non-heating and heating season, respectively, in the suspended particulate matters from the streams showed that PAH source from air deposition was more important for Yongding New River than that for South Drainage Canal and North Drainage Canal. Source apportionment based on PAH profiles indicated that coal combustion was the major PAH contamination source, and coke oven sources and wood combustion also contributed to the PAH contamination of the streams. This was further indicated by organic petrography analysis. 相似文献
967.
Introduction: Occupational Health and Safety (OHS) stakeholders rarely factor the cost of workplace accidents into prevention spending decisions. The lack of consideration of this key information is related to the fact that the scientific literature has failed to provide OHS stakeholders with a cost-calculation tool that is both sufficiently accurate and does not require a data-collection stage ill-suited to the time constraints of workplace decision-makers. Method: This study reviews the recent literature to identify key elements that should foster the use of indirect-cost calculation methods by decision makers. Results: A “local” approach currently appears to be the best method for calculating indirect costs of workplace incidents or accidents in comparison to “bottom-up” or “top-down” approach. This paper discusses four criteria that this type of approach must satisfy to be compatible with the time constraints and accuracy demands of OHS stakeholders in organizations. In addition, four bases for the development of a new indirect cost estimation model are presented and discussed. Impact on industry: this study provides bases and criteria to help the development of indirect-cost calculation models better suited to workplace use than those currently available. 相似文献
968.
Galante-Oliveira S Oliveira I Ferreira N Santos JA Pacheco M Barroso C 《Journal of environmental monitoring : JEM》2011,13(2):304-312
Nucella lapillus (dog whelk) imposex levels were assessed along the mainland Portuguese coast in 2006 and 2008 and were compared with available data from 2003 for the same area. Given that specimen size has been described as a factor inducing variation in some of the imposex assessment indices, and thus resulting in less reliable results, new monitoring and data analysis procedures are described and applied to study change of imposex levels from 2003 to 2008. A significant decline in imposex intensity was observed in the study area during the study period, and the Portuguese coast ecological status (under the terms defined by the OSPAR Commission) notably improved after 2003, confirming the effectiveness of the Regulation (EC) No. 782/2003 in reducing TBT pollution. Nevertheless, N. lapillus populations are still extensively affected by imposex, and fresh TBT inputs were detected in seawater throughout the coast in 2006. These recent inputs are attributed to vessels still carrying TBT antifoulants applied before 2003, as their presence in vessels was only forbidden in 2008. Considering that Regulation (EC) No. 782/2003 is an anticipation of the IMO global ban entered into force in September 2008, a worldwide-scale decrease in TBT pollution can be expected in the near future. 相似文献
969.
Santos MJ Sousa JP Tiago I Veríssimo A Lemos MF 《Journal of environmental monitoring : JEM》2011,13(8):2102-2104
Changes in saprophytic organism's gut microbial communities may present a threat to organic matter breakdown which can ultimately lead to soil function impairment. In this study, Amplified Ribosomal DNA Restriction Analysis (ARDRA) was evaluated as a potential simple molecular tool to assess shifts in bacterial community structure in hindgut populations of Porcellio dilatatus exposed to contaminated food. This prospective tool can also be used for a variety of purposes and samples prior to the use of more specific and sophisticated methods. 相似文献
970.
Yuxue Kong Xurong Bai Jie Wei Yanqin Ren Rui Gao Fahe Chai Hong Li Fei Xu 《环境科学学报(英文版)》2023,123(1):169-182
Polycyclic aromatic hydrocarbons(PAHs) and their nitrated derivatives(NPAHs) attract continuous attention due to their outstanding carcinogenicity and mutagenicity. In order to investigate the diurnal variations, sources, formation mechanism, and health risk assessment of them in heating season, particulate matter(PM) were collected in Beijing urban area from December 26, 2017 to January 17, 2018. PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry(GC-MS). ... 相似文献