全文获取类型
收费全文 | 3379篇 |
免费 | 72篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 124篇 |
废物处理 | 102篇 |
环保管理 | 611篇 |
综合类 | 549篇 |
基础理论 | 881篇 |
环境理论 | 9篇 |
污染及防治 | 816篇 |
评价与监测 | 196篇 |
社会与环境 | 149篇 |
灾害及防治 | 47篇 |
出版年
2023年 | 14篇 |
2022年 | 17篇 |
2021年 | 41篇 |
2020年 | 20篇 |
2019年 | 33篇 |
2018年 | 80篇 |
2017年 | 78篇 |
2016年 | 86篇 |
2015年 | 87篇 |
2014年 | 97篇 |
2013年 | 246篇 |
2012年 | 164篇 |
2011年 | 203篇 |
2010年 | 150篇 |
2009年 | 166篇 |
2008年 | 175篇 |
2007年 | 209篇 |
2006年 | 206篇 |
2005年 | 150篇 |
2004年 | 113篇 |
2003年 | 104篇 |
2002年 | 116篇 |
2001年 | 66篇 |
2000年 | 60篇 |
1999年 | 49篇 |
1998年 | 50篇 |
1997年 | 60篇 |
1996年 | 46篇 |
1995年 | 54篇 |
1994年 | 49篇 |
1993年 | 31篇 |
1992年 | 33篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 12篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 19篇 |
1985年 | 17篇 |
1984年 | 19篇 |
1983年 | 21篇 |
1982年 | 17篇 |
1981年 | 17篇 |
1980年 | 18篇 |
1979年 | 20篇 |
1978年 | 15篇 |
1977年 | 10篇 |
1965年 | 12篇 |
1962年 | 8篇 |
1957年 | 10篇 |
排序方式: 共有3484条查询结果,搜索用时 953 毫秒
621.
Sandra Uthes Katharina Fricke Peter Zander Stefan Sieber Annette Piorr 《Ecological modelling》2010,221(18):2136-2152
The Common Agricultural Policy (CAP), a system of market support instruments, direct income transfers, and rural development measures, has been put through an ongoing reform process in recent decades. This paper introduces three policy impact assessment tools (SIAT, SEAMLESS-IF, MEA-Scope tool) and analyses how these tools have responded to a number of challenges for integrated assessment modelling as reported in the international literature. Significant progress has been made with regard to modelling linkages whereas other challenges, particularly those related to issues of scale and uncertainty management, require further efforts. It is also analysed which CAP instruments are represented and what kinds of effects can be analysed at different scales. Market instruments and direct payments are comparatively well represented, while the ability to model rural development measures is mostly beyond the scope of these tools. Because each tool has found a different solution for coping with the common challenges of integrated assessment modelling, the choice of one of the tools for a particular application depends strongly on the policy questions being asked. The SIAT provides the big picture via its ability to represent broad changes in policy instruments with EU-wide cross-sector impacts. The most comprehensive analysis of agricultural policy instruments can be obtained with SEAMLESS-IF. The MEA-Scope tool complements the other two approaches with detailed regional profiles. 相似文献
622.
Adam F. A. Pellegrini Brian D. Wisenden Peter W. Sorensen 《Behavioral ecology and sociobiology》2010,64(3):381-387
A behavioral syndrome is a suite of behaviors correlated across multiple social contexts. In this study, boldness in the face
of predation risk was assessed twice in fish across two different sensory modalities in both the field and lab to ascertain
the biological relevance and complexity of this attribute. Individual fathead minnows were captured from a natural field population
using traps that either contained chemical alarm cues (conspecific skin extract) or control (well water) and their responses
to the presence of predator behind a glass partition assessed in the laboratory. Although fewer fish were captured in alarm
cue-labeled traps, these bold fish performed longer predator inspections than shy fish captured in control traps. Thus, a
shy/bold behavioral syndrome was expressed consistently across field and lab settings in response to both chemical and visual
indicators of danger. Shy and bold individuals did not differ in sex, body length, secondary sexual characteristics, or parasite
load but were of more robust physical condition. 相似文献
623.
Susan Barrett Peter Whittle Kerrie Mengersen Richard Stoklosa 《Environmental and Ecological Statistics》2010,17(4):503-519
We consider the problem of designing a surveillance system to detect a broad range of invasive species across a heterogeneous
sampling frame. We present a model to detect a range of invertebrate invasives whilst addressing the challenges of multiple
data sources, stratifying for differential risk, managing labour costs and providing sufficient power of detection. We determine
the number of detection devices required and their allocation across the landscape within limiting resource constraints. The
resulting plan will lead to reduced financial and ecological costs and an optimal surveillance system. 相似文献
624.
Christian J. Jerome H.C. Neil Ganey Mustapha Mouloua Peter A. Hancock 《International journal of occupational safety and ergonomics》2013,19(4):539-546
A central concern of Intelligent Transportation Systems (ITS) is the effect of in-vehicle devices (e.g., cell phones, navigation systems, radios, etc.) on driver performance and safety. As diverse and innovative technologies are designed and implemented for in-vehicle use, questions regarding the presence and use of these devices assume progressively greater importance. Further concerns for advanced driver training require us to develop and validate reliable and effective procedures for assessing such effects. This work examines a number of candidate procedures, in particular the evaluation of change in cognitive workload as a strategy by which such goals might be achieved. 相似文献
625.
Bradley Chase Waldemar Karwowski Michael E. Benedict Peter M. Quesada Holly M. Irwin-Chase 《International journal of occupational safety and ergonomics》2013,19(1):5-15
A visual-visual dual computer task was designed to test the effect of the thermal environment on dual task performance. The temperatures selected for testing were 20 and 35 °C Wet Bulb Globe Temperature (WBGT). 34 volunteers were randomly assigned to 1 of the 2 temperature conditions. Individual differences in single task performance were controlled by equating the baselines of single task performance. Once individual differences in single task capacity were controlled, statistically significant differences in performance were demonstrated. Mean accuracy was computed over a 1-hr testing period in each temperature condition. Participants’ mean accuracy in the 35° condition (38.18%) was substantially lower than in the 20° condition (50.88%). 相似文献
626.
Peter Vink Mathilde Miedema Ernst Koningsveld Henk van der Molen 《International journal of occupational safety and ergonomics》2013,19(1):71-82
Bricklaying is a physically demanding job. Bricklayers frequently flex their trunk to pick up bricks and mortar and position these in a wall. The experienced workload is highest working with bricks at 0 to 50 cm from the floor. In this study the effects of 2 devices that have proven to be feasible in practice are evaluated.The 50 cm raise due to the 2 devices is experienced as comfortable, the estimated lumbar compression force was reduced, and observations indicate likewise. It is discussed that the field experiments have many drawbacks. Nevertheless, based on this study in combination with other literature the improvements could be recommended. 相似文献
627.
ABSTRACTThe global industrial food system is increasingly recognised as a source of poor health that deepens social and economic inequity. Health advocates, policy makers, and food activists strive to improve nutrition and food access across racial and ethnic divides; however, given established approaches, they may miss fundamental pathways for improving health and justice comprehensively. While food access and nutrition are often identified as primary concerns for marginalised communities and the reason for food insecurity and food-related illness, critical food justice scholars use a more expansive lens to suggest a democratised food system is needed, and that solutions based solely in access to healthy food can undermine more systemic approaches. Our research extends this analysis, highlighting the importance of endemic food culture (foodways) as a tool for retaining identity, building community, and maintaining health among refugee populations in one community in Salt Lake City, Utah. Further, this work suggests that community engagement and expertise is essential in leveraging foodways such that marginalised communities can effectively resist cheap, unhealthy, and placeless calories. 相似文献
628.
Peter J. Tango Richard A. Batiuk 《Journal of the American Water Resources Association》2013,49(5):1007-1024
Achieving and maintaining the water quality conditions necessary to protect the aquatic living resources of the Chesapeake Bay and its tidal tributaries has required a foundation of quantifiable water quality criteria. Quantitative criteria serve as a critical basis for assessing the attainment of designated uses and measuring progress toward meeting water quality goals of the Chesapeake Bay Program partnership. In 1987, the Chesapeake Bay Program partnership committed to defining the water quality conditions necessary to protect aquatic living resources. Under section 303(c) of the Clean Water Act, States and authorized tribes have the primary responsibility for adopting water quality standards into law or regulation. The Chesapeake Bay Program partnership worked with U.S. Environmental Protection Agency to develop and publish a guidance framework of ambient water quality criteria with designated uses and assessment procedures for dissolved oxygen, water clarity, and chlorophyll a for Chesapeake Bay and its tidal tributaries in 2003. This article reviews the derivation of the water quality criteria, criteria assessment protocols, designated use boundaries, and their refinements published in six addendum documents since 2003 and successfully adopted into each jurisdiction's water quality standards used in developing the Chesapeake Bay Total Maximum Daily Load. 相似文献
629.
The geologic and geomorphic expressions of a mineral deposit determine its location, size, and accessibility, characteristics which in turn greatly influence the success of artisans mining the deposit. Despite this critical information, which can be garnered through studying the surficial physical expression of a deposit, the geologic and geomorphic sciences have been largely overlooked in artisanal mining‐related research. This study demonstrates that a correlation exists between the roles of female miners at artisanal diamond and gold mining sites in western and central Africa and the physical expression of the deposits. Typically, women perform ore processing and ancillary roles at mine sites. On occasion, however, women participate in the extraction process itself. Women were found to participate in the extraction of ore only when a deposit had a thin overburden layer, thus rendering the mineralized ore more accessible. When deposits required a significant degree of manual labour to access the ore due to thick overburden layers, women were typically relegated to other roles. The identification of this link encourages the establishment of an alternative research avenue in which the physical and social sciences merge to better inform policymakers, so that the most appropriate artisanal mining assistance programs can be developed and implemented. 相似文献
630.
Joseph PM 《Environment international》2008,34(8):1185-1191
Our previous paper entitled "Paradoxical ozone associations could be due to methyl nitrite from combustion of methyl ethers or esters in engine fuels" (Env. Int.. 2007;33;1090) reviewed 11 studies of the impact of ozone on human health that, paradoxically, found a negative coefficient for ozone-morbidity associations. We argued that the most likely explanation for this effect would be methyl nitrite (MN) as an unsuspected exhaust component of engines with methyl ether in the fuel. The basis of the argument was the fact that MN is rapidly destroyed by sunlight, so that MN would be negatively correlated with ozone. All (but one) of the reviewed studies concluded that criterion pollutants could not explain the negative slope. The argument was strengthened by the observation that such paradoxical ozone associations have not been found in regions without significant methyl ether in gasoline. Left unaddressed in the previous paper was the possibility that fine particulate matter (FPM) might explain the POA. If this were true, then it would be necessary that the FPM be negatively correlated with ozone in those regions that found a POA. The current paper reviews data on FPM-ozone correlations in those regions where a POA was identified. The results show that FPM was, in most cases, positively correlated with ozone and so could not explain the POA. 相似文献