全文获取类型
收费全文 | 4912篇 |
免费 | 139篇 |
国内免费 | 61篇 |
专业分类
安全科学 | 271篇 |
废物处理 | 168篇 |
环保管理 | 1245篇 |
综合类 | 534篇 |
基础理论 | 1349篇 |
环境理论 | 8篇 |
污染及防治 | 992篇 |
评价与监测 | 317篇 |
社会与环境 | 173篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 57篇 |
2022年 | 55篇 |
2021年 | 55篇 |
2020年 | 62篇 |
2019年 | 69篇 |
2018年 | 122篇 |
2017年 | 133篇 |
2016年 | 179篇 |
2015年 | 122篇 |
2014年 | 160篇 |
2013年 | 407篇 |
2012年 | 232篇 |
2011年 | 304篇 |
2010年 | 202篇 |
2009年 | 237篇 |
2008年 | 260篇 |
2007年 | 255篇 |
2006年 | 227篇 |
2005年 | 195篇 |
2004年 | 180篇 |
2003年 | 148篇 |
2002年 | 140篇 |
2001年 | 86篇 |
2000年 | 94篇 |
1999年 | 68篇 |
1998年 | 74篇 |
1997年 | 60篇 |
1996年 | 63篇 |
1995年 | 78篇 |
1994年 | 74篇 |
1993年 | 66篇 |
1992年 | 57篇 |
1991年 | 39篇 |
1990年 | 35篇 |
1989年 | 36篇 |
1988年 | 30篇 |
1987年 | 39篇 |
1986年 | 40篇 |
1985年 | 39篇 |
1984年 | 44篇 |
1983年 | 44篇 |
1982年 | 53篇 |
1981年 | 43篇 |
1980年 | 31篇 |
1979年 | 15篇 |
1978年 | 29篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1972年 | 7篇 |
1971年 | 9篇 |
排序方式: 共有5112条查询结果,搜索用时 46 毫秒
331.
Factors controlling the transport of geogenically-derived arsenic from a coastal acid sulfate soil into downstream sediments are identified in this study with both solid-phase associations and aqueous speciation clearly critical to the mobility and toxicity of arsenic. The data from both sequential extractions and X-ray adsorption spectroscopy indicate that arsenic in the unoxidised Holocene acid sulfate soils is essentially non-labile in the absence of prolonged oxidation, existing primarily as arsenopyrite or as an arsenopyrite-like species, likely arsenian pyrite. Anthropogenically-accelerated pedogenic processes, which have oxidised this material over time, have greatly enhanced the potential bioavailability of arsenic, with solid-phase arsenic almost solely present as As(V) associated with secondary Fe(III) minerals present. Analyses of downstream sediments reveal that a portion of the arsenic is retained as a mixed As(III)/As(V) solid-phase, though not at levels considered to be environmentally deleterious. Determination of arsenic speciation in pore waters using high performance liquid chromatography/Inductively Coupled Plasma-Mass Spectrometry shows a dominance of As(III) in upstream pore waters whilst an unidentified As species reaches comparative levels within the downstream, estuarine locations. Pore water As(V) was detected at trace concentrations only. The results demonstrate the importance of landscape processes to arsenic transport and availability within acid sulfate soil environments. 相似文献
332.
McGoldrick DJ Durham J Leknes H Kierkegaard A Gerhards R Powell DE McLachlan MS 《Chemosphere》2011,85(8):1241-1247
Cyclic volatile methyl siloxanes (cVMS) are high volume production chemicals used in a wide range of industrial and consumer products. Three cVMS compounds (D4, D5, and D6) have and are undergoing environmental risk evaluations in several countries and have been proposed for legal regulation in Canada. As interest in monitoring concentrations of these chemicals in the environment increase, there is a need to evaluate the analytical procedures for cVMS in biological matrices in order to assess the quality of data produced. The purpose of this study was to determine laboratory testing performance for measuring residues of D4, D5, and D6 in a standard set of fish homogenate samples and to estimate limits of determination for each substance. The samples sent to each laboratory consisted of homogenized whole body tissues of hatchery raised rainbow trout which were fed food fortified with D4, D5, and D6 (dosed) and trout that were fed standard food rations (control). The participants analyzed each sample using their analytical method of choice using their own standards and procedures for quantification and quality control. With a few exceptions, participating laboratories generated comparable results for D4, D5, and D6 in both the dosed and control samples having z-scores between 2 and −2. Method detection limits for the whole fish matrix were on average 2.4 ng g−1 ww for D4, 2.3 ng g−1 ww for D5, and 1.8 ng g−1 ww for D6. 相似文献
333.
Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia-nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH4-N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH4-N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH4-N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia-nitrogen at the maximum, but a faster decrease of leachate concentration levels. 相似文献
334.
Dimkpa CO Calder A Britt DW McLean JE Anderson AJ 《Environmental pollution (Barking, Essex : 1987)》2011,159(7):1749-1756
The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells’ periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes. 相似文献
335.
Farooque AA Zaman QU Madani A Abbas F Percival DC Esau TJ 《Journal of environmental science and health. Part. B》2011,46(4):366-379
Land application of biosolids from processed sewage sludge may deteriorate soil, water, and plants. We investigated the impact of the N-Viro biosolids land-application on the quality of the soil water that moved through Orthic Humo-Ferric Podzols soil of Nova Scotia (NS) at the Wild Blueberry Research Institute, Debert, NS Canada. In addition, the response of major soilproperties and crop yield was also studied. Wild blueberry (Vaccinium angustifolium. Ait) was grown under irrigated and rainfed conditions in 2008 and 2009. Four experimental treatments including (i) NI: N-Viro irrigated, (ii) NR: N-Viro rainfed, (iii) FI: inorganic fertilizer irrigated, and (iv) FR: inorganic fertilizer rainfed (control) were replicated 4 times under randomized complete block design. Soil samples were collected at the end of each year and analyzed for changes in cation exchange capacity (CEC), soil organic matter (SOM), and pH.Soil water samples were collected four times during the study period from the suction cup lysimeters installed within and below crop root zone at 20 and 40 cm depths, respectively. The samples were analyzed for a range of water quality parameters including conductance, hardness, pH, macro- and micronutrients, and the infectious pathogens Escherichia coli (E. coli) and salmonella. Berries were harvested for fruit yield estimates. Irrigation significantly increased CEC during 2008 and the soil pH decreased from 4.93 (2008) to 4.79 (2009). There were significant influences of irrigation, fertilizer, and their interaction, in some cases, on most of the soil water quality parameters except on the infectious bacteria. No presence of E. coli or salmonella were observed in soil and water samples, reflecting the absence of these bacteria in biosolids used in this experiment. Nutrient concentration in the soil water samples collected from the four treatments were higher in the sequence NI > NR > FI > FR. The irrigation treatment had significant effect on the unripe fruit yield. We conclude that the comparable performance of N-Viro biosolids and the increasing prices of inorganic fertilizers would compel farmers to use economically available N-Viro biosolids that, coupled with the supplemental irrigation, did not deteriorate the studied soil properties, soil water quality, and the wild blueberry yield during this experiment. 相似文献
336.
Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil 总被引:2,自引:0,他引:2
Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm3-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg−1 of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl2 extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated. 相似文献
337.
Stevens CJ Duprè C Dorland E Gaudnik C Gowing DJ Bleeker A Diekmann M Alard D Bobbink R Fowler D Corcket E Mountford JO Vandvik V Aarrestad PA Muller S Dise NB 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2243-2250
A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha−1 yr−1) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate. 相似文献
338.
The Jordan River is among the world’s most famous and culturally and historically significant waterways. The lower stretch of the river, however, has been a victim of development in a water scarce region, with current flows less than 5 % of historical levels. Furthermore, as it functions as an international border in a region of conflict, access to the river and its potential as a tourist attraction has been limited. Recently, there have been numerous calls for rehabilitation of the river. This study presents a first estimate of the economic benefits of such rehabilitation and compares them to the estimated costs. Identical contingent valuation method surveys were administered in Israel, Jordan, and the Palestinian Authority. Evidence from this study shows that, despite the large opportunity costs of increasing environmental flows, rehabilitation of the lower Jordan would produce positive net economic benefits. This is true even though the study estimated only the benefits to local populations, and not to international tourists or those outside the region. Net benefits are maximized when taking a regional, as opposed to strictly national, approach. 相似文献
339.
Zhu Ting Ganesh P. Shivakoti Chen Haiyun David Maddox 《Environment, Development and Sustainability》2012,14(2):197-220
Community-based co-management (CBCM) mechanisms for forest management have matured through the development of new economic
analysis and common property theory. However, while many local CBCM mechanisms have been initiated in Chinese Natural Reserves,
there are few objective, data-based evaluations of whether these mechanisms improve forest conservation and local livelihoods.
This research uses Baishuijiang National Natural Reserve (BNNR) as a study case to evaluate China’s current CBCM mechanisms.
The evaluation is based mainly on three criteria: efficiency, equality and sustainability of project operation. Survey data
indicate that local CBCM mechanisms provide a wide-participation platform for local villagers, associated administration managers,
research institutions and NGOs to join in forest resource protection work while improving local livelihood. CBCM projects
have also facilitated a reduction in forest resource dependency, the improvement of household income and encouragement of
local people to participate in forest resource protection. Our analysis suggests that most CBCM organizations have made progress
in efficiency, equity and sustainability. However, further study should focus on how to deal with the lingering problems of
inequity in responsibility and rights among CBCM committee members, poor distribution of benefits, insufficient program-design
and management expertise, faulty information dissemination, and insufficient capital investment. 相似文献
340.
de Nazelle A Nieuwenhuijsen MJ Antó JM Brauer M Briggs D Braun-Fahrlander C Cavill N Cooper AR Desqueyroux H Fruin S Hoek G Panis LI Janssen N Jerrett M Joffe M Andersen ZJ van Kempen E Kingham S Kubesch N Leyden KM Marshall JD Matamala J Mellios G Mendez M Nassif H Ogilvie D Peiró R Pérez K Rabl A Ragettli M Rodríguez D Rojas D Ruiz P Sallis JF Terwoert J Toussaint JF Tuomisto J Zuurbier M Lebret E 《Environment international》2011,37(4):766-777