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   293篇
  免费   0篇
  国内免费   8篇
安全科学   17篇
废物处理   10篇
环保管理   47篇
综合类   49篇
基础理论   53篇
污染及防治   84篇
评价与监测   19篇
社会与环境   19篇
灾害及防治   3篇
  2023年   8篇
  2022年   13篇
  2021年   18篇
  2020年   8篇
  2019年   4篇
  2018年   5篇
  2017年   9篇
  2016年   6篇
  2015年   7篇
  2014年   9篇
  2013年   36篇
  2012年   9篇
  2011年   12篇
  2010年   11篇
  2009年   14篇
  2008年   11篇
  2007年   15篇
  2006年   15篇
  2005年   12篇
  2004年   6篇
  2003年   10篇
  2002年   3篇
  2001年   1篇
  2000年   3篇
  1999年   2篇
  1998年   4篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   5篇
  1993年   3篇
  1992年   3篇
  1991年   1篇
  1990年   4篇
  1989年   4篇
  1987年   1篇
  1986年   4篇
  1985年   1篇
  1983年   1篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1978年   2篇
  1973年   2篇
  1955年   1篇
  1938年   1篇
  1933年   1篇
  1931年   2篇
  1926年   1篇
  1920年   1篇
排序方式: 共有301条查询结果,搜索用时 15 毫秒
141.
The Salinas River watershed along the central coast of California, U.S.A., supports rapidly growing urban areas and intensive agricultural operations. The river drains to an estuarine National Wildlife Refuge and a National Marine Sanctuary. The occurrence, spatial patterns, sources and causesof aquatic toxicity in the watershed were investigated by sampling four sites in the main river and four sites in representative tributaries during 15 surveys between September1998 and January 2000. In 96 hr toxicity tests, significant Ceriodaphnia dubia mortality was observed in 11% of the mainriver samples, 87% of the samples from a channel draining anurban/agricultural watershed, 13% of the samples fromchannels conveying agricultural tile drain runoff, and in 100% of the samples from a channel conveying agricultural surface furrow runoff. In six of nine toxicity identificationevaluations (TIEs), the organophosphate pesticides diazinon and/or chlorpyrifos were implicated as causes of observed toxicity, and these compounds were the most probable causes oftoxicity in two of the other three TIEs. Every sample collectedin the watershed that exhibited greater than 50% C. dubia mortality (n = 31) had sufficient diazinon and/or chlorpyrifos concentrations to account for the observed effects.Results are interpreted with respect to potential effects on other ecologically important species.  相似文献   
142.
Universities have long borne an influential role in sustainability. Nonetheless, the affinity toward eclectic and piecemeal practices has been addressed as oxymoron to the essence of sustainable development, and the need to hone campus members’ buy-in is credited to be cardinal for systemic transformation. Major attributes for systemic campus sustainability are identified, incorporated, and proposed via a conceptual model. Those attributes are key sustainable development areas as well as perception and motivation on the topics that must be taken into consideration by universities to be able to adhere to a more pragmatic and inclusive sustainable development. Thus, the central intent of the authors is to offer a mechanism which may facilitate as well as elevate systemic campus sustainability. An extensive review of the literature in the area of sustainability, perception, and motivation is conducted, which includes articles, journals, conference proceedings, university reports, books, and materials from websites. By extracting and integrating crucial constituents of sustainable development from various studies, this paper contributes to the existing literature on sustainable development providing an input to the implementation of systemic campus sustainability.  相似文献   
143.
Against a backdrop of continuous deforestation and the degradation of forest resources, this paper is an attempt to develop auspicious criteria and indicators of forest sustainability for Cameroon, drawing from the strength and weaknesses of those currently applicable. Using data emanating from both secondary and primary sources, this paper concludes that while the adoption and implementation of the criteria for forest sustainability should normally lead to sustainability, it should not be taken for granted because sustainability is not an abstract concept, but measurable. Thus, whether or not forest in Cameroon is sustainable can only be ascertained through the effective application of the criteria and indicators delineated in this paper.  相似文献   
144.
Heat stress on workers working outdoors in the power industry may result in fatigue and deterioration in task performance. This research collected and analyzed data on task performance of workers working indoors and outdoors with and without a cooling suit. The task performance was compared on the basis of heart rate, oxygen consumption, tympanic temperature, subjective responses, productivity, and error rates. Based on One-Way Analysis Of Variance (ANOVA) results, a significantly lower estimated working oxygen consumption was observed (p < .001) when the cooling suit was worn. The productivity was higher while workers wore the cooling suit as compared to no cooling suit (p = .011) whereas the error rates were significantly lower(p < .001). Also a significantly lower self-reported discomfort was observed in the neck and shoulders while working wearing the cooling suit (p = .004). This study concluded that wearing a cooling suit while working outdoors was associated with physiological benefits as well as improved task performance of the study participants.  相似文献   
145.
This paper presents a mixed integer nonlinear programming (MINLP) model to improve the computational use of the layer of protection analysis (LOPA). For a given set of independent protection layers to be implemented in a process, the proposed optimization model is solved to: a) Include costs associated with the different prevention, protection and mitigation devices, and b) Satisfy the risk level typically specified in the LOPA analysis through the occurrence probability. The underline purpose focuses on improving the analysis process and decision making to obtain the optimal solution in the safeguards selection that satisfies the requirements to be considered as IPL’s. The optimization is based on economic and risk tolerance criteria. As a first stage of this proposal, the safety instrumented system (SIS) design is optimized so that the selection of SIS components minimizes the risk and satisfies the safety integrity level (SIL) requirements. A case study is presented to validate the whole proposed approach.  相似文献   
146.
Environmental Science and Pollution Research - The motivation for the current study stem from the United Nations Sustainable Development Goals (UN-SDGs) such as access to clean (SDG-7) and...  相似文献   
147.
In the present work we describe the photocatalytic degradation of methylbutandioic acid (MBA), focusing particularly on adsorption of the MBA on TiO2 surface. We observe a very fast surface carboxylate formation, a decrease of the surface carboxylates during the reaction and an apparent zero order kinetic for the degradation of MBA. We conclude that the main way of MBA degradation is its reaction in the solution, and not on the surface of TiO2. The influence of the surface carboxylates on the efficiency of the catalyser is under study.  相似文献   
148.
Both the advanced oxidation process (AOP) using a combination of hydrogen peroxide addition and microwave heating (H2O2/microwave), and the microwave heating process were used for solubilization of phosphorus from liquid dairy manure. About 80% of total phosphate was released into the solution at a microwave heating time of 5 min at 170 degrees C. With an addition of H2O2, more than 81% of total phosphate could be released over a reaction period of 49 h at ambient temperature. The AOP process could achieve up to 85% of total phosphate release at 120 degrees C. The results indicated that both the microwave, and the AOP processes could effectively release phosphate from liquid dairy manure. These processes could serve as pretreatments for phosphorus recovery from animal wastes, and could be combined with the struvite crystallization process to provide a new approach in treating animal wastes.  相似文献   
149.
Environmental Science and Pollution Research - Polyvinylidene fluoride (PVDF) blended with varying concentrations of titanium nanotubes (TNT) was electrospun to result in a nanocomposite filter...  相似文献   
150.

The United Nations Climate Conference 25, held in December 2019, reached a significant agreement against implementing the Paris agreement come 2020. Bound by the contract, 189 countries who are party to the deal agreed to constrain worldwide temperature to ascend to 1.5° Celsius. To this end, the present study attempts to investigate the readiness of selected countries in the European Union to implement the agreement, which will better the quality of the global environment. In line with this, this study appraises the connection between economic growth, renewable and non-renewable energy consumption, on emissions in 11 countries in the European Union from 1990 to 2016. The study utilises the Pooled Mean Group-Auto Regressive Distributed Lag (PMG-ARDL) model estimator and Dumitrescu and Hurlin Panel Causality analysis to analyse the long-run and short-run impact and direction of causality among these factors, respectively. The long-run study's empirical results show a U-shaped Environmental Kuznets Curve (EKC) and a negative connection between renewable energy use and emissions in the EU-11 countries. In the short-run, non-renewable energy use worsens CO2 emissions while renewable energy use leads to a fall in emissions. Similarly, causality tests show a feedback mechanism between emissions and renewable energy use and between non-renewable energy and renewable use. Also, there is unidirectional causality from income to CO2 emissions, non-renewable energy use to CO2 emissions. The investigation recommends an expanded proportion of renewable energy sources in the EU countries’ energy mix to cut down on emissions.

  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