全文获取类型
收费全文 | 17425篇 |
免费 | 158篇 |
国内免费 | 141篇 |
专业分类
安全科学 | 380篇 |
废物处理 | 696篇 |
环保管理 | 2078篇 |
综合类 | 3960篇 |
基础理论 | 3922篇 |
环境理论 | 7篇 |
污染及防治 | 4402篇 |
评价与监测 | 1101篇 |
社会与环境 | 1117篇 |
灾害及防治 | 61篇 |
出版年
2022年 | 127篇 |
2021年 | 151篇 |
2019年 | 128篇 |
2018年 | 248篇 |
2017年 | 237篇 |
2016年 | 363篇 |
2015年 | 305篇 |
2014年 | 427篇 |
2013年 | 1154篇 |
2012年 | 477篇 |
2011年 | 711篇 |
2010年 | 550篇 |
2009年 | 631篇 |
2008年 | 711篇 |
2007年 | 756篇 |
2006年 | 673篇 |
2005年 | 546篇 |
2004年 | 590篇 |
2003年 | 556篇 |
2002年 | 545篇 |
2001年 | 675篇 |
2000年 | 410篇 |
1999年 | 307篇 |
1998年 | 201篇 |
1997年 | 226篇 |
1996年 | 238篇 |
1995年 | 252篇 |
1994年 | 244篇 |
1993年 | 220篇 |
1992年 | 210篇 |
1991年 | 220篇 |
1990年 | 203篇 |
1989年 | 184篇 |
1988年 | 174篇 |
1987年 | 158篇 |
1986年 | 155篇 |
1985年 | 152篇 |
1984年 | 173篇 |
1983年 | 170篇 |
1982年 | 181篇 |
1981年 | 153篇 |
1980年 | 135篇 |
1979年 | 130篇 |
1978年 | 135篇 |
1977年 | 116篇 |
1976年 | 105篇 |
1975年 | 109篇 |
1974年 | 118篇 |
1971年 | 100篇 |
1967年 | 103篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
791.
Anna Maria J?nsson Olle Anderbrant Jennie Holmér Jacob Johansson Guy Schurgers Glenn P. Svensson Henrik G. Smith 《Ambio》2015,44(3):249-255
In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science–stakeholder collaboration, and in a two-way dialog link empirical experience and impact modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science–stakeholder communication. By this, we hope to stimulate a discussion among the science–stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models. 相似文献
792.
The aim of this study was to determine the level of 26 polycyclic aromatic hydrocarbons (PAHs) at parking garages and to provide the necessary annual information based on occupational inhalation exposure and non-occupational inhalation exposure, which carry risks for the environment. For this purpose, 22 samples were collected continuously from both gas and particulates phase PAHs from two parking garages at Konya City Center, Turkey. The exposure-based risk of these samples was evaluated using concentrations of the carcinogenic PAH compounds. None of the 26 PAHs measured had values exceeding the recommended exposure limits (RELs) standard values for inhalation rate recommended by the World Health Organization (WHO). Exposure levels of gas and particulate PAHs for the occupational group and the public (children and adults who spend time in shopping centers) were found to be 0.07–28.24 μgm?3 and 0.05–5.753 μgm?3, respectively, representing levels two to four times higher than those at the control site. Maximum daily inhalation of B[a]Py was estimated at 1.33 ngd?1 for exposure of the public and as 274 ngd?1 for the occupational group. It is believed that traffic makes a substantial contribution to the PAH profile, which had relatively high concentrations of naphthalene (Napth) and coronene (Coro). Highly carcinogenic dibenzo(a,l)pyrene (B[al]Pyre) was found in the ambient air at two parking garages. Napth and phenanthrene (Phen) were the main compounds found in nearly all the tested samples. In this study, benzo[e]pyrene (B[e]Py) was used as a reference for PAHs because its concentration is stable and does not change seasonally. Considering the importance of these compounds in relation to human health, the aim of this work was to characterize and quantify the more toxic PAHs in parking garages. Conducting PAH sampling and their chemical analysis is very costly and labor intensive. This study produced data that can be a powerful tool for environmental forensics. 相似文献
793.
Patrick Smallhorn-West Jan van der Ploeg Delvene Boso Meshach Sukulu Janet Leamae Mathew Isihanua Martin Jasper Janet Saeni-Oeta Margaret Batalofo Grace Orirana Alick Konamalefo Jill Houma Hampus Eriksson 《Ambio》2022,51(6):1504
Coastal fisheries are a critical component of Pacific island food systems; they power village economies and provide nutritious aquatic foods. Many coastal women and men actively fishing in this region rely on multi-species fisheries, which given their extraordinary diversity are notoriously difficult to both characterize, and to manage. Understanding patterns of fishing, diversity of target species and drivers of these patterns can help define requirements for sustainable management and enhanced livelihoods. Here we use a 12-month data set of 8535 fishing trips undertaken by fishers across Malaita province, Solomon Islands, to create fisheries signatures for 13 communities based on the combination of two metrics; catch per unit effort (CPUE) and catch trophic levels. These signatures are in turn used as a framework for guiding suitable management recommendations in the context of community-based resource management. While a key proximate driver of these patterns was fishing gear (e.g. angling, nets or spearguns), market surveys and qualitative environmental information suggest that community fishing characteristics are coupled to local environmental features more than the market value of specific species they target. Our results demonstrate that even within a single island not all small-scale fisheries are equal, and effective management solutions ultimately depend on catering to the specific environmental characteristics around individual communities.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01690-z. 相似文献
794.
Canhada João C. S. Paiva Fábio F. G. Shinohara Gabriel M. M. Okimoto Fernando Hiranobe Carlos T. Teixeira Silvio R. Job Aldo E. Santos Renivaldo J. 《Journal of Material Cycles and Waste Management》2023,25(2):944-953
Journal of Material Cycles and Waste Management - Leather production is a technology that boosts the economy because of its versatility and durability. However, the wastes generated throughout the... 相似文献
795.
Lunag Marcelino N. Abana Alexander S. Agcaoili Juco P. Arellano Jillien Kaith T. Caluza Coleen Angela G. Decena Nick Brylle V. Paz Emmanuel R. Dela Delgado Lyka Angela B. Obero Aaron F. Ocampo Don Miguel E. Sacdalan Charlene Ann D. 《Journal of Material Cycles and Waste Management》2023,25(2):1216-1226
Journal of Material Cycles and Waste Management - The daily use of facemask to prevent virus transmission increases the negative effect on the environment because of improper waste disposal. Due to... 相似文献
796.
Christian Mrz Felipe S. Freitas Johan C. Faust Jasmin A. Godbold Sian F. Henley Allyson C. Tessin Geoffrey D. Abbott Ruth Airs Sandra Arndt David K. A. Barnes Laura J. Grange Neil D. Gray Ian M. Head Katharine R. Hendry Robert G. Hilton Adam J. Reed Saskia Rühl Martin Solan Terri A. Souster Mark A. Stevenson Karen Tait James Ward Stephen Widdicombe 《Ambio》2022,51(2):370
Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy. 相似文献
797.
Factors affecting TCLP lead leachability from computer CPUs 总被引:1,自引:0,他引:1
The factors impacting lead leachability from computer central processing units (CPUs) during the toxicity characteristic leaching procedure (TCLP) were investigated. Several CPUs were disassembled and their component materials were decreased in size to meet the requirements of the TCLP. The impact of CPU composition was examined by leaching different combinations of the CPU components. The ferrous metal content of the mixture greatly impacted lead leaching. TCLP lead concentrations of CPUs predicted by leaching the lead-bearing printed wire boards alone were much greater than those measured when the ferrous metal of the CPU was included in the mixture. The leaching of iron and zinc from the galvanized steel components of the CPU created electrochemical conditions where lead was less soluble. Additional size reduction beyond that required by the TCLP did not result in additional lead leaching. As the volume of head space above the leaching solution increased, the concentration of lead measured increased as well. 相似文献
798.
Effects of the forced ventilation on composting of a solid olive-mill by-product ("alperujo") managed by mechanical turning 总被引:1,自引:0,他引:1
Cegarra J Alburquerque JA Gonzálvez J Tortosa G Chaw D 《Waste management (New York, N.Y.)》2006,26(12):1377-1383
The evaluation of the most suitable aeration technology for olive-mill by-product "alperujo" (AL) composting was carried out by using two identical piles prepared by mixing AL with a bulking agent (fresh cow bedding) and a mature compost (as inoculant). Forced ventilation was employed in conjunction with mechanical turning in one of the piles, whereas only mechanical turning was used in the other pile. These two treatment methods were evaluated by assessing process efficiency and end-product quality. The results show that the composting process was completed in less time when forced ventilation was coupled with mechanical turning. A slight delay in the evolution of pH, C/N ratio, and biodegradation of fats and organic matter was observed when only turning was employed. However, the recommended method for composting AL was mechanical turning without forced ventilation since the composition of the end-product in this case was comparable to the composted AL using forced ventilation coupled with mechanical turning. Furthermore, there were substantial economic savings by selecting mechanical turning alone, which included capital costs for equipment. 相似文献
799.
The capacity of anaerobic granular sludge to remove selenate from contaminated wastewater was investigated. The potential of different types of granular sludge to remove selenate from the liquid phase was compared to that of suspended sludge and contaminated soil and sediment samples. The selenate removal rates ranged from 400 to 1500 microg g VSS(-1) h(-1), depending on the source of biomass, electron donor, and the initial selenate concentration. The granular structure protects the microorganisms when exposed to high selenate concentrations (0.1 to 1 mM). Anaerobic granular sludge "Eerbeek," originating from a UASB reactor treating paper mill wastewater, removed about 90, 50, and 36% of 0.1, 0.5, and 1 mM of Se, respectively, from the liquid phase when incubated with 20 mM lactate at 30 degrees C and pH 7.5. Selenite, elemental Se (Se(o)), and metal selenide precipitates were the conversion products. Enrichments from the anaerobic granular sludge "Eerbeek" were able to convert 90% of the 10-mM selenate to Se(o) at a rate of 1505 microg Se(VI) g cells(-1) h(-1), a specific growth rate of 0.0125 g cells h(-1), and a yield of 0.083 g cells mg Se(-1). Both microbial metabolic processes (e.g dissimilatory reduction) as well as microbially mediated physicochemical mechanisms (adsorption and precipitation) contribute to the removal of selenate from the Se-containing medium. 相似文献
800.
Runion GB Davis MA Pritchard SG Prior SA Mitchell RJ Torbert HA Rogers HH Dute RR 《Journal of environmental quality》2006,35(4):1478-1486
Plant species vary in response to atmospheric CO2 concentration due to differences in physiology, morphology, phenology, and symbiotic relationships. These differences make it very difficult to predict how plant communities will respond to elevated CO2. Such information is critical to furthering our understanding of community and ecosystem responses to global climate change. To determine how a simple plant community might respond to elevated CO2, a model regenerating longleaf pine community composed of five species was exposed to two CO2 regimes (ambient, 365 micromol mol(-1) and elevated, 720 micromol mol(-1)) for 3 yr. Total above- and belowground biomass was 70 and 49% greater, respectively, in CO2-enriched plots. Carbon (C) content followed a response pattern similar to biomass, resulting in a significant increase of 13.8 Mg C ha(-1) under elevated CO2. Responses of individual species, however, varied. Longleaf pine (Pinus palustris Mill.) was primarily responsible for the positive response to CO2 enrichment. Wiregrass (Aristida stricta Michx.), rattlebox (Crotalaria rotundifolia Walt. Ex Gmel.), and butterfly weed (Asclepias tuberosa L.) exhibited negative above- and belowground biomass responses to elevated CO2, while sand post oak (Quercus margaretta Ashe) did not differ significantly between CO2 treatments. As with pine, C content followed patterns similar to biomass. Elevated CO2 resulted in alterations in community structure. Longleaf pine comprised 88% of total biomass in CO2-enriched plots, but only 76% in ambient plots. In contrast, wiregrass, rattlebox, and butterfly weed comprised 19% in ambient CO2 plots, but only 8% under high CO2. Therefore, while longleaf pine may perform well in a high CO2 world, other members of this community may not compete as well, which could alter community function. Effects of elevated CO2 on plant communities are complex, dynamic, and difficult to predict, clearly demonstrating the need for more research in this important area of global change science. 相似文献