全文获取类型
收费全文 | 4579篇 |
免费 | 32篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 67篇 |
废物处理 | 163篇 |
环保管理 | 209篇 |
综合类 | 1760篇 |
基础理论 | 932篇 |
环境理论 | 8篇 |
污染及防治 | 1092篇 |
评价与监测 | 207篇 |
社会与环境 | 176篇 |
灾害及防治 | 7篇 |
出版年
2019年 | 41篇 |
2018年 | 82篇 |
2017年 | 87篇 |
2016年 | 106篇 |
2015年 | 96篇 |
2014年 | 109篇 |
2013年 | 205篇 |
2012年 | 105篇 |
2011年 | 199篇 |
2010年 | 133篇 |
2009年 | 137篇 |
2008年 | 216篇 |
2007年 | 181篇 |
2006年 | 150篇 |
2005年 | 128篇 |
2004年 | 117篇 |
2003年 | 110篇 |
2002年 | 140篇 |
2001年 | 86篇 |
2000年 | 75篇 |
1999年 | 60篇 |
1998年 | 54篇 |
1997年 | 45篇 |
1996年 | 47篇 |
1995年 | 52篇 |
1994年 | 52篇 |
1993年 | 34篇 |
1992年 | 43篇 |
1991年 | 40篇 |
1990年 | 41篇 |
1989年 | 33篇 |
1981年 | 31篇 |
1977年 | 32篇 |
1976年 | 32篇 |
1973年 | 34篇 |
1968年 | 31篇 |
1967年 | 42篇 |
1966年 | 34篇 |
1965年 | 55篇 |
1964年 | 41篇 |
1963年 | 45篇 |
1962年 | 39篇 |
1961年 | 51篇 |
1960年 | 46篇 |
1959年 | 53篇 |
1958年 | 54篇 |
1957年 | 46篇 |
1956年 | 49篇 |
1955年 | 44篇 |
1954年 | 44篇 |
排序方式: 共有4621条查询结果,搜索用时 515 毫秒
291.
Felton Adam Löfroth Therese Angelstam Per Gustafsson Lena Hjältén Joakim Felton Annika M. Simonsson Per Dahlberg Anders Lindbladh Matts Svensson Johan Nilsson Urban Lodin Isak Hedwall P. O. Sténs Anna Lämås Tomas Brunet Jörg Kalén Christer Kriström Bengt Gemmel Pelle Ranius Thomas 《Ambio》2020,49(5):1065-1066
Ambio - In the original published article, the sentence “Nevertheless, semi-natural forest remnants continue to be harvested and fragmented (Svensson et al. 2018; Jonsson et al. 2019), and... 相似文献
292.
Russian Journal of Ecology - Technogenic pollution can accelerate microevolutionary processes in natural populations. We estimated the nuclear DNA content of 10 Bromus inermis Leyss. samples from... 相似文献
293.
In this study, dry season radon flux densities and radon fluxes have been determined at the rehabilitated Nabarlek uranium mine in northern Australia using conventional charcoal canisters. Environmental background levels amounted to 31± 15 milli Becquerel per m2 per second (mBq m−2 s−1). Radon flux densities within the fenced rehabilitated mine area showed large variations with a maximum of 6500 mBq m−2 s−1 at an area south of the former pit characterised by a disequilibrium between 226Ra and 238U. Radon flux densities were also high above the areas of the former pit (mean 971 mBq m−2 s−1) and waste rock dump (mean 335 mBq m−2 s−1). The lower limit for the total pre-mining radon flux from the fenced area (140 ha) was estimated to 214 kBq s−1, post-mining radon flux amounted to 174 kBq s−1.Our study highlights that the results of radon flux studies are vitally dependant on the selection of individual survey points. We suggest the use of a randomised system for both the selection of survey points and the placement of charcoal canisters at each survey point, to avoid over estimation of radon flux densities. It is also important to emphasize the significance of having reliable pre-mining radiological data available to assess the success of rehabilitation of a uranium mine site.2006 Springer. The Australian Government's right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
294.
Bioaerosol sampling by a personal rotating cup sampler CIP 10-M 总被引:1,自引:0,他引:1
Görner P Fabriès JF Duquenne P Witschger O Wrobel R 《Journal of environmental monitoring : JEM》2006,8(1):43-48
High concentrations of bioaerosols containing bacterial, fungal and biotoxinic matter are encountered in many workplaces, e.g. solid waste treatment plants, waste water treatment plants and sewage networks. A personal bioaerosol sampler, the CIP 10-M (M-microbiologic), has been developed to measure worker exposure to airborne biological agents. This sampler is battery operated; it is light and easy to wear and offers full work shift autonomy. It can sample much higher concentrations than biological impactors and limits the mechanical stress on the microorganisms. Biological particles are collected in 2 ml of liquid medium inside a rotating cup fitted with radial vanes to maintain an air flow rate of 10 l min(-1) at a rotational speed of approximately 7,000 rpm. The rotating cup is made of sterilisable material. The sampled particles follow a helicoidal trajectory as they are pushed to the surface of the liquid by centrifugal force, which creates a thin vertical liquid layer. Sterile water or another collecting liquid can be used. Three particle size selectors allow health-related aerosol fractions to be sampled according to international conventions. The sampled microbiological particles can be easily recovered for counting, incubation or further biochemical analysis, e.g., for airborne endotoxins. Its physical sampling efficiency was laboratory tested and field trials were carried out in industrial waste management conditions. The results indicate satisfactory collection efficiency, whilst experimental application has demonstrated the usefulness of the CIP 10-M personal sampler for individual bioaerosol exposure monitoring. 相似文献
295.
Ozdilek HG 《Environmental monitoring and assessment》2006,122(1-3):203-219
Rapid industrialization and urbanization in Turkey, especially over the last twenty five years, has provided better living standards to its residents, but it also caused a decrease in environmental quality. In late 1970's, air quality monitoring activities were started in some major cities by individual researchers in Turkey. It was just around the 1990's that a countrywide program on continuous air pollution monitoring in major province centers and selected large towns was launched. The impact of air pollution on people depend on various factors, such as existence and magnitude of coal powered energy generation plants, type of urban heating and their efficiency, and the numbers and specifications of vehicles. In this study, current Turkish urban air quality over the turn of the Millennium (1992–2001) is studied in the light of the country's worst cities in terms of outdoor air quality, the number of upper respiratory diseases, sinusitis, bronchitis, and pneumonia cases in these provinces reported by the state medical treatment facilities in 2001. The population that is under outdoor urban air pollution hazard was computed. A comparative analysis between the provinces that use natural gas and others that use fossil fuels was also completed in order to project monetary gains if the studied provinces will transform their indoor heating and industrial operations to be run by natural gas or other cleaner energy sources. If natural gas use in air polluted urban centers could be realized in the near future, approximately 212 to 350 million US dollars per annum could to be saved just by reducing health related problems caused by outdoor air pollution. 相似文献
296.
G. Venkatesh Åsa Nyflött Chris Bonnerup Magnus Lestelius 《Environment, Development and Sustainability》2018,20(4):1483-1497
The purpose of a barrier coating in food packaging is primarily to increase the shelf life of the foodstuff contained within the packaging, preserve its colour, odour, taste and quality, and thereby reduce food wastage (both at retail outlets and households). While most publications hitherto have compared packaging and barrier-coating materials on the basis of their environmental impacts alone, this paper adopts a more holistic approach by factoring in the economic aspect as well. Four barrier material alternatives—starch, polyethylene, EVOH + kaolin and latex + kaolin are analysed. Two well-defined end-of-life handling scenarios, relevant to Sweden, are: one in which everything except starch is recycled, with starch being composted, and the other in which everything is incinerated. Among the several environmental impact categories which can be analysed, this paper considers only global warming. Two approaches are tested to combine the economic and environmental aspects—normalisation, weighting and aggregating on the one hand, and using the carbon tax to internalise the externality caused by GHG emissions on the other. For the set of weighting factors obtained thanks to a survey conducted by the authors (40.6% for environmental and 59.4% for economic), starch emerges as the most sustainable alternative, followed by polyethylene for both the end-of-life handling scenarios. This tallies with the result obtained by using the carbon tax for internalisation of the externality. The case study, methodology and results presented in this paper, will hopefully be a springboard for more detailed studies of this nature, under the umbrella of sustainability. 相似文献
297.
Jean-Baptiste E. Thomas Jonas Nordström Emma Risén Maria E. Malmström Fredrik Gröndahl 《Ambio》2018,47(4):398-409
Efforts are on the way on the Swedish West Coast to develop the capacity for cultivation of marine resources, notably of kelps. Given that this is a region of great natural and national heritage, public opposition to marine developments has been identified as a possible risk factor. This survey thus sought to shed light on awareness levels, perceptions of different types of aquaculture and on reactions to a scenario depicting future aquaculture developments on the West Coast. When asked about their general opinions of aquaculture, respondents tended to be favourable though a majority chose neutral responses. On the whole, respondents were favourable to the depicted scenario. Finally, it was found that the high-awareness group tended to be more supportive than the low or medium-awareness groups, hinting at the benefits of increasing awareness to reduce public aversion and to support a sustainable development of aquaculture on the Swedish West Coast. 相似文献
298.
299.
Gabriela Eguren Noelia Rivas-Rivera Claudio García Bernardo Böcking Santiago Bandeira 《Environmental monitoring and assessment》2018,190(12):710
Agricultural systems have experienced rapid expansion and intensification in the last several decades. In Uruguay, since the beginning of 2000, the most common cropping systems have included soybeans. Currently, this crop is expanding towards lowlands traditionally occupied by rice in rotation with pastures. However, the environmental effects of agricultural intensification and diversification are not well known. Thus, some indices have been proposed to quantify the changes in agricultural production systems and assess water quality. The main goal of this study was to develop a water quality index (WQI) to assess the impacts of the diversification of rice production systems in northwest Uruguay. The study was carried out in an agricultural basin where other summer crops have been incorporated in the rice-pasture sequence. Agriculture intensification and crop diversification indices were calculated using information provided by farmers. Water samples were collected downstream of the production area before crop sowing and after crop harvest (2008–2009 to 2010–2011 and 2016–2017 to 2017–2018). Biochemical oxygen demand, nitrates, total phosphorus, fecal coliforms, and total suspended solids were the variables that mainly explained the effects of the agricultural activities on water quality. The proposed water quality index included these unweighted variables, which allowed for the pre-sowing and post-harvest to be differentiated, as well as the degree of diversification. Therefore, the proposed WQI constitutes a tool that can be used to evaluate the water quality in an agricultural basin. Likewise, it can be used to select agricultural sequences that generate the least possible impacts on the associated water resources. 相似文献
300.
Carbon dioxide emissions have accelerated since the signing of the Kyoto Protocol. This discouraging development may partly
be blamed on accelerating world growth and on lags in policy instruments. However, it also raises serious question concerning
whether policies to reduce CO2 emissions are as effective as generally assumed. In recent years, a considerable number of studies have identified various
feedback mechanisms of climate policies that often erode, and occasionally reinforce, their effectiveness. These studies generally
focus on a few feedback mechanisms at a time, without capturing the entire effect. Partial accounting of policy feedbacks
is common in many climate scenarios. The IPCC, for example, only accounts for direct leakage and rebound effects. This article
attempts to map the aggregate effects of different types of climate policy feedback mechanisms in a cohesive framework. Controlling
feedback effects is essential if the policy measures are to make any difference on a global level. A general conclusion is
that aggregate policy feedback mechanisms tend to make current climate policies much less effective than is generally assumed.
In fact, various policy measures involve a definite risk of ‘backfiring’ and actually increasing CO2 emissions. This risk is particularly pronounced once effects of climate policies on the pace of innovation in climate technology
are considered. To stand any chance of controlling carbon emissions, it is imperative that feedback mechanisms are integrated
into emission scenarios, targets for emission reduction and implementation of climate policy. In many cases, this will reduce
the scope for subsidies to renewable energy sources, but increase the scope for other measures such as schemes to return carbon
dioxide to the ground and to mitigate emissions of greenhouse gases from wetlands and oceans. A framework that incorporates
policy feedback effects necessitates rethinking the design of the national and regional emission targets. This leads us to
a new way of formulating emission targets that include feedback effects, the global impact target. Once the full climate policy feedback mechanisms are accounted for, there are probably only three main routes in climate
policy that stand a chance of mitigating global warming: (a) returning carbon to the ground, (b) technological leaps in zero-emission
energy technology that make it profitable to leave much carbon in the ground even in Annex II countries and (c) international
agreements that make it more profitable to leave carbon in the ground or in forests. 相似文献