全文获取类型
收费全文 | 1360篇 |
免费 | 24篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 53篇 |
环保管理 | 279篇 |
综合类 | 124篇 |
基础理论 | 392篇 |
环境理论 | 1篇 |
污染及防治 | 327篇 |
评价与监测 | 83篇 |
社会与环境 | 70篇 |
灾害及防治 | 11篇 |
出版年
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 16篇 |
2019年 | 12篇 |
2018年 | 25篇 |
2017年 | 12篇 |
2016年 | 44篇 |
2015年 | 30篇 |
2014年 | 34篇 |
2013年 | 125篇 |
2012年 | 35篇 |
2011年 | 67篇 |
2010年 | 48篇 |
2009年 | 60篇 |
2008年 | 56篇 |
2007年 | 71篇 |
2006年 | 57篇 |
2005年 | 52篇 |
2004年 | 40篇 |
2003年 | 44篇 |
2002年 | 45篇 |
2001年 | 39篇 |
2000年 | 27篇 |
1999年 | 26篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 20篇 |
1995年 | 34篇 |
1994年 | 19篇 |
1993年 | 20篇 |
1992年 | 13篇 |
1991年 | 25篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 9篇 |
1987年 | 16篇 |
1986年 | 15篇 |
1985年 | 11篇 |
1984年 | 25篇 |
1983年 | 10篇 |
1982年 | 14篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 12篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 5篇 |
1971年 | 7篇 |
排序方式: 共有1387条查询结果,搜索用时 147 毫秒
231.
Introduction: China's rapid motorization has resulted in significant challenges in road safety. Method: Using official national statistics, this study examines road traffic injuries (RTIs) experienced by foreigners in China. The number of foreigners entering China has increased 2.4 times over the study period, from 10.16 million in 2000 to 24.33 million in 2008. Results: From 2000- 2008, the number of road traffic fatalities among foreigners similarly increased 2.5 fold, including 49 fatalities reported in 2008. Nonfatal RTIs during this same time frame increased by a magnitude of 1.8 (126 nonfatal injuries in 2000 to 223 in 2008). Conclusions: This study suggests that the total number of foreigners working or visiting China each year who suffer fatal and nonfatal road traffic injuries is relatively low. Impact on Industry: This study provided evidence suggesting that foreigners visiting or working in China face a relatively low risk of road traffic injuries. 相似文献
232.
Kristen A. Conner Author Vitae Author Vitae Gary A. Smith Author Vitae 《Journal of Safety Research》2010,41(1):17-23
Introduction
The purpose of this study was to analyze linked crash and hospital data to determine the effect that enactment of a standard enforcement safety belt law in Ohio would have on hospital charges and direct medical costs due to motor-vehicle crashes, focusing on the impact to the state's Medicaid system.Method
The linkage and analysis was conducted as part of the Ohio Crash Outcome Data Evaluation System (CODES) program. Current safety belt usage in Ohio stands at 82% with its secondary enforcement safety belt law.Results
Assuming an increase in usage to 92% through standard enforcement, over $15.3 million in medical costs to Medicaid for injuries that occur in a single year could be prevented over a 10-year period. Cumulative savings could reach more than $91.2 million during the 10-year period. In addition, 161 fatalities could have been prevented in one year had all unbelted occupants who sustained a fatal injury instead chosen to wear their safety belt.Summary and Impact on Industry
Clearly, substantial progress can be made in reducing the number of deaths and injuries, as well as medical costs associated with motor-vehicle crashes, by strengthening safety belt laws and increasing safety belt usage in Ohio. 相似文献233.
Donna K. McNeese‐Smith 《组织行为杂志》1999,20(2):243-259
This ex‐post facto/correlational study examines the relationships among the following variables: nurse manager motivation for power, achievement and affiliation (N=19), managerial leadership behaviors, staff nurse outcomes of job satisfaction, productivity and organizational commitment (N=221) and patient satisfaction (N=299). Results show that managerial motivation for power is negatively correlated with manager use of leadership behaviors and staff nurse job satisfaction but positively correlated with patient satisfaction. Managerial motivation for achievement is positively correlated with use of leadership behaviors as well as nurse job satisfaction, productivity and organizational commitment, and generally to patient satisfaction. Managerial motivation for affiliation reveals few significant positive or negative relationships with other variables. The researcher concludes that both power and achievement motivation of the manager influence staff and patient outcomes in health care in the 1990s. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
234.
235.
The invasive non-native shrub Rosa rugosa (Japanese Rose) is well-established in many northwest European countries where, especially on coastal sand-dunes, it forms large dominant stands with adverse effects on semi-natural vegetation and biota of high conservation status. Its recent increase in England’s largest dune system on the Sefton Coast in north Merseyside led to an investigation into its rate of spread. Using digitised aerial photographs and GIS methodology, sample patches of old-established R. rugosa were found to have grown in area by an average of 22 % per annum between 1989 and 2013. This rate of increase is comparable to that found in Denmark and higher than reported for several other woody plants in coastal dunes. In the absence of management, R. rugosa could soon dominate large areas on the Sefton Coast, with serious consequences for amenity and the nature conservation interest of the dune system. 相似文献
236.
C. L. Huffard S. von Thun A. D. Sherman K. Sealey K. L. Smith Jr. 《Marine Biology》2014,161(12):2735-2751
Pelagic forms of the brown algae (Phaeophyceae) Sargassum spp. and their conspicuous rafts are defining characteristics of the Sargasso Sea in the western North Atlantic. Given rising temperatures and acidity in the surface ocean, we hypothesized that macrofauna associated with Sargassum in the Sargasso Sea have changed with respect to species composition, diversity, evenness, and sessile epibiota coverage since studies were conducted 40 years ago. Sargassum communities were sampled along a transect through the Sargasso Sea in 2011 and 2012 and compared to samples collected in the Sargasso Sea, Gulf Stream, and south of the subtropical convergence zone from 1966 to 1975. Mobile macrofauna communities exhibited changes in community structure and declines in diversity and evenness within a 6-month time period (August 2011–February 2012). Equivalent declines in diversity and evenness were recorded in the same region (Sargasso Sea, 25°–29°N) in 1972–1973. Recent community structures were unlike any documented historically, whether compared to sites of the same latitude range within the Sargasso Sea, or the broader historical dataset of sites ranging across the Sargasso Sea, Gulf Stream, and south of the subtropical convergence zone. Recent samples also recorded low coverage by sessile epibionts, both calcifying forms and hydroids. The diversity and species composition of macrofauna communities associated with Sargassum might be inherently unstable. While several biological and oceanographic factors might have contributed to these observations, including a decline in pH, increase in summer temperatures, and changes in the abundance and distribution of Sargassum seaweed in the area, it is not currently possible to attribute direct causal links. 相似文献
237.
Pierre Mérel Aaron Smith Jeffrey Williams Emily Wimberger 《Journal of Environmental Economics and Management》2014
Not as much abatement as has been presumed. Smog check programs aim to curb tailpipe emissions from in-use vehicles by requiring repairs whenever emissions, measured at regular time intervals, exceed a certain threshold. Using data from California, we estimate that on average 41% of the initial emissions abatement from repairs is lost by the time of the subsequent inspection, normally two years later. Our estimates imply that the cost per pound of pollution avoided is an order of magnitude greater for smog check repairs than alternative policies such as new-vehicle standards or emissions trading among industrial point sources. 相似文献
238.
ABSTRACTThis article contributes to efforts to validate a common set of parameters and principles of sustainable agriculture. Comparisons between alternative forms of sustainable agriculture and rural-to-urban community resilience are investigated. Conclusions are drawn between multiple sustainable/alternative agriculture systems and evaluated. A set of common baseline parameters and principles is proposed as a method of evolving a common structural framework for strengthening sustainability of agriculture and rural contexts. Concepts of rural-to-urban community sustainability are proposed, supporting sustainable agriculture contexts as rural and urban. In the twenty-first century, agriculture is becoming more diversified and less typified as a rural occupation. Urban agriculture is expanding as the need for fresh, affordable, accessible agriculture produce increases in urban areas. Evidence supports symbiotic relationships between sustainable agriculture and rural/urban communities, although some claim this relationship has not been clearly defined.This article investigates sustainable agriculture from two perspectives. We ask ‘what are common parameters and principles of the various forms of sustainable agriculture,’ and ‘why urban-to-rural context.’ Organic agriculture parameters and principles are proposed as a conceptual framework toward establishing baseline parameters and principles for sustainable agriculture. Best management parameters of urban and rural sustainable agriculture in the United States and the United Kingdom are examined for their potential to develop a strengthening framework of parameters and principles of agriculture and rural-to-urban sustainability. These results are compared and evaluated for their effectiveness in redefining current sustainable agriculture practices, and their value in strengthening sustainable agriculture symbiosis with rural-to-urban community systems. 相似文献
239.
Mohammad Salehi Bardia Panahbehagh Afshin Parvardeh David R. Smith Yuancai Lei 《Environmental and Ecological Statistics》2013,20(4):571-590
Adaptive two-stage sequential sampling (ATSSS) design was developed to observe more rare units and gain higher efficiency, in the sense of having a smaller variance estimator, than conventional sampling designs with equal effort for rare and spatially cluster populations. For certain rare populations, incorporating auxiliary variables into a sampling design can further improve the observation of rare units and increase efficiency. In this article, we develop regression-type estimators for ATSSS so that auxiliary variables can be incorporated into the ATSSS design when warranted. Simulation studies on two populations show that the regression-type estimators can significantly increase the efficiency of ATSSS and the detection of more rare units as compared to conventional sampling counterparts. Simulation of sampling of desert shrubs in Inner Mongolia (one of the two populations studied) showed that by incorporating a GIS auxiliary variable into ATSSS with the regression estimators resulted in a gain in efficiency over ATSSS without the auxiliary variable. Further, we found that the use of the GIS auxiliary variable in a conventional two-stage design with a regression estimator did not show a gain in efficiency. 相似文献
240.
Adrian A. Smith Jocelyn G. Millar Lawrence M. Hanks Andrew V. Suarez 《Behavioral ecology and sociobiology》2012,66(9):1267-1276
Eusociality is characterized by a reproductive division of labor, wherein workers respond to the presence of reproductive individuals by refraining from reproduction themselves and restricting the reproductive efforts of others. Our understanding of how eusociality is maintained therefore depends on characterizing the mechanism by which workers detect the presence of a reproductive. Variations in cuticular hydrocarbons correspond to changes in reproductive ability in ants, and experimental studies are beginning to reveal the function of hydrocarbons as signals. In this study, we compare the cuticular hydrocarbon profiles of dominant and reproductive workers and queens of the ant Odontomachus brunneus with profiles of non-reproductive workers. Using split/reunification tests we document the existence of worker policing in both queenless and queenright colonies; supernumerary reproductives were treated aggressively by nestmates. Finally, we induce aggression and replicate queen-like submissive nestmate responses by supplementing the hydrocarbon profile of workers with (Z)-9-nonacosene, a compound that was significantly more abundant on the cuticles of reproductives. In three bioassays, we compare this manipulation to various control manipulations of the hydrocarbon profile and demonstrate that workers gauge the reproductive activity of nestmates through changes in their cuticular hydrocarbon profiles. 相似文献