首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   273篇
  免费   6篇
  国内免费   8篇
安全科学   19篇
废物处理   25篇
环保管理   45篇
综合类   25篇
基础理论   48篇
污染及防治   54篇
评价与监测   51篇
社会与环境   13篇
灾害及防治   7篇
  2023年   3篇
  2022年   5篇
  2021年   7篇
  2020年   4篇
  2019年   8篇
  2018年   13篇
  2017年   10篇
  2016年   10篇
  2015年   11篇
  2014年   12篇
  2013年   28篇
  2012年   13篇
  2011年   11篇
  2010年   9篇
  2009年   14篇
  2008年   9篇
  2007年   20篇
  2006年   9篇
  2005年   14篇
  2004年   8篇
  2003年   10篇
  2002年   8篇
  2001年   6篇
  2000年   9篇
  1999年   6篇
  1998年   3篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1993年   7篇
  1992年   4篇
  1991年   2篇
  1989年   1篇
  1988年   1篇
  1982年   1篇
  1981年   1篇
  1979年   2篇
排序方式: 共有287条查询结果,搜索用时 31 毫秒
101.
Australia, a country which has regularly experienced various natural disasters, is now set to face more intense and frequent disasters in the twenty-first century as a result of climate change. Prior research indicates that in Australia, the perceived risks of climate change are mixed and becoming less prevalent across rural and urban locations, posing a threat to the public’s adoption of mitigation and adaptation strategies. Research was conducted in four disaster-impacted rural Australian towns to investigate whether prior disaster experience, trust in climate change risk communications and specific location predicted climate change risk perceptions. Four case study sites were chosen exemplifying communities impacted by different types of disaster events. The case study towns were Beechworth (wildfire, 2009) and Bendigo (drought, 2002–2008) in Victoria; Ingham (flood, 2009) and Innisfail (cyclone, 2006) in Queensland. Structural equation modelling analyses of surveys returned by a sample of 1,008 householders across the four towns showed that prior disaster experience had no impact upon climate change risk perceptions. Instead climate change risk perceptions were predicted by trust in climate change communications, climate change knowledge and the geographical location of the sample, suggesting the need for targeted, place-specific contextual communication interventions that consider the needs and socioeconomic characteristics of the community in question.  相似文献   
102.
To recognize properties of a mixture of Vistula sand (medium sand acc. to USCS) with Slovak zeolite as reactive materials suitable for permeable reactive barriers proposed for protection of groundwater environment in vicinity of old landfills comprehensive laboratory investigations were performed. The present study investigates the removal of contaminants specific for landfill leachates onto zeolite-sand mixtures containing 20%, 50% and 80% of zeolite (ZS20, ZS50 and ZS80). Taking into account the results of batch tests it was concluded that the Langmuir isotherm best fitted the data. It was observed that the presence of ammonium, calcium and magnesium decreases the removal efficiency of copper by 32%. Column tests of contaminant migration through the attenuation zone of the reactive materials were interpreted using the software package CXTFIT, which solves a one-dimensional advection-dispersion equation. Column test results also indicate the strong influence of the presence of interfering substances on copper immobilisation; dynamic sorption capacities decrees twofold. Throughout the landfill leachate flow through ZS80 sample, a constant reduction of NH+4 (at 100%), K+ (at 93%) and Fe total (at an average of 86%) were observed. There was no reduction in chemical oxygen demand and biochemical oxygen demand.  相似文献   
103.

Emission inventories (EIs) are the fundamental tool to monitor compliance with greenhouse gas (GHG) emissions and emission reduction commitments. Inventory accounting guidelines provide the best practices to help EI compilers across different countries and regions make comparable, national emission estimates regardless of differences in data availability. However, there are a variety of sources of error and uncertainty that originate beyond what the inventory guidelines can define. Spatially explicit EIs, which are a key product for atmospheric modeling applications, are often developed for research purposes and there are no specific guidelines to achieve spatial emission estimates. The errors and uncertainties associated with the spatial estimates are unique to the approaches employed and are often difficult to assess. This study compares the global, high-resolution (1 km), fossil fuel, carbon dioxide (CO2), gridded EI Open-source Data Inventory for Anthropogenic CO2 (ODIAC) with the multi-resolution, spatially explicit bottom-up EI geoinformation technologies, spatio-temporal approaches, and full carbon account for improving the accuracy of GHG inventories (GESAPU) over the domain of Poland. By taking full advantage of the data granularity that bottom-up EI offers, this study characterized the potential biases in spatial disaggregation by emission sector (point and non-point emissions) across different scales (national, subnational/regional, and urban policy-relevant scales) and identified the root causes. While two EIs are in agreement in total and sectoral emissions (2.2% for the total emissions), the emission spatial patterns showed large differences (10~100% relative differences at 1 km) especially at the urban-rural transitioning areas (90–100%). We however found that the agreement of emissions over urban areas is surprisingly good compared with the estimates previously reported for US cities. This paper also discusses the use of spatially explicit EIs for climate mitigation applications beyond the common use in atmospheric modeling. We conclude with a discussion of current and future challenges of EIs in support of successful implementation of GHG emission monitoring and mitigation activity under the Paris Climate Agreement from the United Nations Framework Convention on Climate Change (UNFCCC) 21st Conference of the Parties (COP21). We highlight the importance of capacity building for EI development and coordinated research efforts of EI, atmospheric observations, and modeling to overcome the challenges.

  相似文献   
104.
In spite of widespread support from most member countries’ societies for European Union policy, including support for the sustainable development idea, in many EU countries the levels of acceptance of new environmental protection programmes have been and, in particular in new member states, still are considerably low. The experience of the countries which were the first to implement union directives show that they cannot be effectively applied without widespread public participation. The goal of this study was, using the example of Poland, to assess public acceptance of the expansion of nature conservation in the context of sustainable development principles and to discover whether existing nature governance should be modified when establishing new protected areas. The increase in protected areas in Poland has become a hotbed of numerous conflicts. In spite of the generally favourable attitudes to nature which Polish people generally have, Natura 2000 is perceived as an unnecessary additional conservation tool. Both local authorities and communities residing in the Natura areas think that the programme is a hindrance, rather than a help in the economic development of municipalities or regions, as was initially supposed. This lack of acceptance results from many factors, mainly social, historic and economic. The implications of these findings for current approach to the nature governance in Poland are discussed.  相似文献   
105.
The acorn barnacle, Semibalanus balanoides, is thought to release larvae in response to phytoplankton blooms, but there is evidence that another, unidentified cue for release may exist. We conducted high-frequency sampling in Little Harbor, Massachusetts, USA, to determine whether early-stage larval abundance was related to several environmental variables, and to characterize vertical distributions of the larvae. Larval concentrations peaked at 2.52 and 1.02 individuals l−1 during two storms. Larvae were more abundant near the surface than near the bottom. We suggest the hypothesis that turbid conditions and upward-swimming behavior may protect newly-released larvae from predation and cannibalism. Future studies should test this hypothesis with barnacles and other invertebrates.  相似文献   
106.

Background

Over the past 20 years, genetically modified organisms (GMOs) have raised enormous expectations, passionate political controversies and an ongoing debate on how these technologies should be assessed. Current risk assessment procedures generally assess GMOs in terms of their potential risk of negatively affecting human health and the environment. Can this risk-benefit approach deliver a robust assessment of GMOs? In this paper, we question the validity of current risk assessment from both a social and an ecological perspective, and we elaborate an alternative approach, namely in-context trajectory evaluation. This paper combines frame analysis, context analysis and ecosocial analysis to three different case studies.

Results

Applying frame analysis to Syngenta's recent campaign 'Bring plant potential to life', we first de-construct the technosocial imaginaries driving GMOs innovation, showing how the latter endorses the technological fix of socioeconomic problems whilst reinforcing the neoliberal sociopolitical paradigm. Applying context analysis to biopharming in New Zealand, we then explore local practices and knowledge, showing that particularities of context typically omitted from risk assessment processes play a key role in determining both the risks and the potential benefits of a technology. Finally, drawing from the Italian case, we outline through ecosocial analysis how the lack of long-term studies, further aggravated by current methodological deficiencies, prevent risk assessment from considering not only how GMOs affect the environmental context but also, and most importantly, the way people live in, and interact with, this context.

Conclusion

Incorporating frame analysis, context analysis and ecosocial analysis, in the form of in-context trajectory evaluation, into the assessment of GMOs can improve the social compatibility, political accountability and ecological sustainability of its outcomes.  相似文献   
107.
A few aspects of skin protection against ultraviolet (UV) light and methods of assessing efficacy of UV-protecting cream or gels have been discussed. UV-protection in cream and gels is not only a strategy of the cosmetic industry but a necessity because of human occupational activity and daily habits.  相似文献   
108.
The concept of an occupational health and safety management system (OH&S MS) has become widespread over the past 20 years. However, there are few studies on the subject, they are generally methodologically weak and in many cases cannot be generalized. A formalized OH&S MS is a set of rules and connected elements of the general organization management system which guarantees accomplishment of the organization?s objectives in the area of upgrading safety conditions of both employees and the environment. The need for research on voluntary management systems stems from the necessity to propagate appropriate solutions and their continuous development processes. This paper discusses an OH&S MS as a source of data and essential information on the process of developing a system. It examines the relationship between the degree to which the requirements of Standard No. PN-N-18001:2004 have been adapted and the demand for health and safety data and information.  相似文献   
109.
Honest advertisement models of sexual selection propose that exaggerated secondary sexual ornaments are condition-dependent, and that only individuals with superior disease resistance will be able to express costly ornamentation. Studies of secondary sexual ornamentation and their maintenance by sexual selection tend to focus on males. However, females may also possess showy ornaments. We investigated whether female ornaments, in the form of sexual swellings, reliably signal female fitness in a semifree-ranging colony of mandrills (Mandrillus sphinx) at the Centre International de Recherches Médicales, Franceville (CIRMF), Gabon. We measured swelling height and width using photographs of periovulatory females over three mating seasons and compared swelling size with parasitism (using fecal analysis over one annual cycle), immune status (ratio of lymphocytes to neutrophils in blood smears made during captures), and genetic diversity (microsatellite heterozygosity). Swelling size varied by up to 10% between cycles in individual females, giving some support to the hypothesis that size differences may indicate the quality of individual swelling cycles. However, there was no significant difference in swelling size between conceptive and nonconceptive cycles. Measures of swelling size varied more between females than within females across swelling cycles, implying that swelling size was a relatively consistent characteristic of individual females. Swelling size was not significantly related to either general measures of parasitism and immune status, or to the closest available measures to each swelling cycle. Nor was swelling size significantly related to genetic diversity. The healthy, provisioned nature of the colony and problems associated with observational, correlational studies restrict interpretation of our data. However, in combination with previous findings that females of higher reproductive success do not show larger swellings, and that males do not allocate mating effort as a function of swelling size, these results imply that sexual swelling size does not indicate female quality in these semifree-ranging mandrills.  相似文献   
110.
Response of soil catalase activity to chromium contamination   总被引:3,自引:0,他引:3  
The impact of chromium(III) and (VI) forms on soil catalase activity was presented. The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from di erent depths were used in the experiment. The soil samples were amended with solution of Cr(III) using CrCl3, and with Cr(VI) using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control. Catalase activity was assayed by one of the commonly used spectrophotometric methods. As it was demonstrated in the experiment, both Cr(III) and Cr(VI) have an ability to reduce soil catalase activity. A chromium dosage of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr(III) and 68% to 76% for Cr(VI), with relation to the control. Catalase activity reached maximum in the soil material from surface layers (0–25 cm), typically characterized by the highest content of organic matter creating favorable conditions for microorganisms.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号