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   523篇
  免费   40篇
  国内免费   6篇
安全科学   27篇
废物处理   23篇
环保管理   133篇
综合类   69篇
基础理论   144篇
污染及防治   124篇
评价与监测   19篇
社会与环境   29篇
灾害及防治   1篇
  2023年   8篇
  2022年   6篇
  2021年   20篇
  2020年   14篇
  2019年   16篇
  2018年   23篇
  2017年   23篇
  2016年   40篇
  2015年   24篇
  2014年   25篇
  2013年   50篇
  2012年   28篇
  2011年   34篇
  2010年   23篇
  2009年   20篇
  2008年   31篇
  2007年   15篇
  2006年   23篇
  2005年   16篇
  2004年   22篇
  2003年   17篇
  2002年   16篇
  2001年   16篇
  2000年   5篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1993年   2篇
  1992年   6篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1984年   3篇
  1983年   1篇
  1982年   4篇
  1981年   2篇
  1980年   3篇
  1979年   4篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有569条查询结果,搜索用时 31 毫秒
511.
Religious harassment claims in the United States have risen sharply over the past decade. However, victims of religious harassment may not always report harassment, and true rates may be higher. Hence, actions taken by third parties present (observers) are important in combating harassment in the workplace. The purpose of this paper is to extend a previous model of observer intervention and related research by testing it empirically in the context of religious harassment and identify factors that influence observers' decision to intervene (intervention), when they intervene (level of immediacy), and how much they intervene (level of involvement). Across two studies, we find evidence that verbal harassment, ambiguity of intent, relationship to target/harasser, recurrence belief, religious commitment, pro‐social orientation, and the interactive effect of shared religion and religious commitment predict intervention. Furthermore, individuals show higher levels of involvement and immediacy in intervention when costs are low and emotional reactions are high. Implications of these findings for engaging observers in combatting harassment are discussed. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
512.
During an inspection of the old Rockhole Mine area in Kakadu National Park in 1999, it was found that a small amount of tailings from the former South Alligator uranium (U) mill had been uncovered by wet season rain and road works. Samples of sediment, water and freshwater mussels, Velesunio angasi, were collected from the South Alligator River, near and at the confluence of Rockhole Mine Creek, and adjacent to the exposed tailings. The 228Ra/226Ra activity ratios in sediments and mussel tissue indicate a small influence from the tailings and from Rockhole Mine adit water on 226Ra concentrations. The uptake of 226Ra in mussels does not correlate with other alkaline-earth metals. Mussel U concentrations are higher immediately downstream of Rockhole Mine Creek, but there is no noticeable increase in the immediate vicinity of the tailings area. A hypothetical ingestion of 2 kg of mussels from the sites was used to estimate the committed effective dose for a 10-year-old child resulting in a figure of 0.23 mSv per annum, of this total dose, 69% is attributed to 210Po. Only 0.03 mSv per annum can be directly linked to impacts of the tailings.  相似文献   
513.
Stawell Gold Mine in NW Victoria, Australia, mines ores that contain large concentrations of As and significant quantities of the metals Pb and Cr. The aim of this research was to understand the dispersion, enrichment and probable exposure of these potentially hazardous elements around the mine site. Fifty-five surface soil samples were collected near the mine (<15 km) and analysed by ICP-MS/OES following bioavailable and four-acid extractions. Soils near the mine show greater concentrations of As, Cr and Pb than those near a regionally determined background. This is attributed to the combination of a natural geochemical halo around mineralization and anthropogenic dispersion due to mining and urbanization. Total As concentrations were between 16 and 946 mg kg−1 near the mine in a regional background of 1–16 mg kg−1. Total Cr concentrations were between 18 and 740 mg kg−1 near the mine in a regional background of 26–143 mg kg−1. Total Pb concentrations were between 12 and 430 mg kg−1 near the mine in a regional background of 9–23 mg kg−1. Dispersion of contaminant elements from the present ore processing is <500 m. The most enriched soils occur close to the town and are unrelated to present mining practices. The bioavailable As, Cr and Pb, soil ingestion rates and Risk Reference Doses were used to estimate health risks. An average toddler (12 kg) would need to consume at least 1.5 g, and most likely 12 g, of soil per day to show some symptoms of As toxicity. The maximum measured bioavailable As would pose a risk at average ingestion rates of 200 mg per day. Individuals with soil-eating disorders would exceed the safe daily consumption limits for As, and potentially Cr and Pb. Small children are not typically exposed to soil everyday, very few have soil eating disorders, and, therefore, the health risk from the soils around the mine is minimal.  相似文献   
514.
515.
IntroductionThis study measured whole-body vibration (WBV) exposures in front-end loader operators, and evaluated the effects of traction chains and work tasks on their WBV exposures.MethodWBV exposures were measured and compared across three different front-end loader tire configurations: (a) stock rubber tires, (b) rubber tires with ladder chains, and (c) rubber tires with basket chains. The operators completed three distinct standardized tasks: driving on a city street, simulated plowing, and a simulated scooping and dumping task. A portable data acquisition system collected tri-axial time weighted and raw WBV data per ISO 2631-1 and 2631-5 standards. In addition, Global Positioning System (GPS) data were collected in order to compare loader speeds across tire conditions and the standardized tasks.ResultsRelative to the stock rubber tires, both types of tire chains significantly increased WBV exposures with the ladder chains having substantially higher WBV exposures compared to basket chains. Additionally, there were task dependent differences in WBV exposures. During the driving task, the z-axis (up and down) was the predominant exposure; the plowing task had a more even distribution of exposure across all three axes; while during scooping and dumping task, the x-axis (fore and aft) had the highest WBV exposures. The GPS data indicated that there were significant speed differences across tasks but not between the basket and ladder chain conditions.ConclusionsTires with ladder chains increased the front-end loader operators' exposure to WBV above the ISO 2631-1 recommended eight hour action limit increasing risk for adverse health effects. Although more expensive, basket chains are recommended over ladder chains since they substantially lowered the front-end loader operator's exposures and may ultimately reduce vibration related wear and tear on the vehicle.Impact on IndustryIn order to reduce a heavy equipment vehicle (HEV) operator’s chances for developing low back pain, this study provides information that health and safety professionals can use to reduce whole-body vibration (WBV) exposures when operating front-end wheel loaders with traction chains.  相似文献   
516.
Abstract

The U.S. Environmental Protection Agency (EPA) published the Regional Haze Rule (RHR) in 1999.1 The RHR default goal is to reduce haze linearly to natural background in 2064 from the baseline period of 2000–2004. The EPA default method2,3 for estimating natural and baseline visibility uses the Interagency Monitoring of Protected Visual Environments (IMPROVE) formula. The IMPROVE formula predicts the light extinction coefficient from aerosol chemical concentrations measured by the IMPROVE network. The IMPROVE light scattering coefficient formula using data from 1994–2002 underestimated the measured light scattering coefficient by 700 Mm?1, on average, on days with precipitation. Also, precipitation occurred as often on the clearest as haziest days. This led to estimating the light extinction coefficient of precipitation, averaged over all days, as the light scattering coefficient on days with precipitation (700 Mm?1) multiplied by the percent of precipitation days in a year. This estimate added to the IMPROVE formula light extinction estimate gives a real world estimate of visibility for the 20% clearest, 20% haziest, and all days. For example, in 1993, the EPAs Report to Congress projected visibility in Class I areas would improve by 3 deciviews by 2010 across the haziest portions of the eastern United States because of the 1990 Clean Air Act Amendments. Omitted was the light extinction coefficient of precipitation. Adding in the estimated light extinction coefficient of precipitation, the estimated visibility improvement declines to <1 deci-view.  相似文献   
517.
518.
Environmental regulations traditionally have been developed to limit pollution emitted to a single environmental medium at a time. This approach has been followed for a variety of reasons—political, legal, and informational, to name a few. However, more efficient environmental management could be achieved if environmental standards were issued simultaneously across all media. In this way multimedia pollutant tradeoffs could be utilized and regulatory uncertainty could be reduced.  相似文献   
519.
Belardo S  Howell A  Ryan R  Wallace WA 《Disasters》1983,7(3):215-220
A microcomputer-based system was developed to provide local officials responsible for disaster management with assistance during the crucial period immediately following a disaster, a period when incorrect decisions could have an adverse impact on the surrounding community.
While the paper focuses on a potential disaster resulting from an accident at a commercial nuclear power generating facility, the system can be applied to other disastrous situations. Decisions involving evacuation, shelter and the deployment of resources must be made in response to floods, earthquakes, accidents in the transportation of hazardous materials, and hurricanes to name a few examples.
As a decision aid, the system was designed to enhance data display by presenting the data in the form of representations (i.e. road maps, evacuation routes, etc.) as well as in list or tabular form. The potential impact of the event (i.e. the release of radioactive material) was displayed in the form of a cloud, representing the dispersion of the radioactive material. In addition, an algorithm was developed to assist the manager in assigning response resources to demands.
The capability for modelling the impact of a disaster is discussed briefly, with reference to a system installed in the communities surrounding the Indian Point nuclear power plant in New York State.
Results demonstrate both the technical feasibility of incorporating microcomputers indecision support systems for radiological emergency response, and the acceptance of such systems by those public officials responsible for implementing the response plans.  相似文献   
520.
This paper identifies some scientific impediments to ecosystem management and describes bio-physical databases required to help systematically and empirically address the ecological sustainability challenge. Examples are drawn from ongoing work in Ontario. This work has implications for efforts in ecological land classification, landscape ecology, more efficient locating of research and monitoring plots, wildlife management and ultimately trade-off analyses. We conclude with the recommendation that the key primary databases, as currently evolving for Ontario, could and should be developed nationally, thereby creating a NatGRID database, i.e., Nationally Georeferenced Resource Information for Decision-making. NatGRID could be used to help address, in a more quantitative manner, fundamental questions regarding ecological sustainability and trade-offs in forest management.  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