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   2286篇
  免费   183篇
  国内免费   114篇
安全科学   116篇
废物处理   12篇
环保管理   669篇
综合类   616篇
基础理论   325篇
环境理论   54篇
污染及防治   23篇
评价与监测   107篇
社会与环境   337篇
灾害及防治   324篇
  2024年   5篇
  2023年   63篇
  2022年   43篇
  2021年   64篇
  2020年   80篇
  2019年   122篇
  2018年   118篇
  2017年   127篇
  2016年   124篇
  2015年   137篇
  2014年   75篇
  2013年   219篇
  2012年   144篇
  2011年   145篇
  2010年   107篇
  2009年   79篇
  2008年   73篇
  2007年   82篇
  2006年   91篇
  2005年   73篇
  2004年   79篇
  2003年   74篇
  2002年   57篇
  2001年   51篇
  2000年   87篇
  1999年   59篇
  1998年   25篇
  1997年   34篇
  1996年   13篇
  1995年   20篇
  1994年   15篇
  1993年   27篇
  1992年   5篇
  1991年   16篇
  1990年   12篇
  1989年   8篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1980年   3篇
  1979年   1篇
  1977年   2篇
  1974年   1篇
  1972年   1篇
  1971年   2篇
排序方式: 共有2583条查询结果,搜索用时 437 毫秒
401.
Abstract

The Bali Roadmap, as the breakthrough on inter-governmental negotiation of climate change mitigation, having brought United States on track, is still a result of compromises. The major compromises of the Bali Roadmap are centered around three issues of quantifying emission reduction targets, developing countries’ obligations as well as quantifying developed countries’ financial assistance in developing countries’ capacity building on climate change. It is found that the rationalities behind these compromises are the national interests. Due to the fact, achieving cohesion among all nations in climate change actions is very difficult. Therefore, the Bali Roadmap may lead to a tough way with distant hope. However, technology innovation and well-designed economic instruments would be helpful and supportive for further international negotiation and cooperation.  相似文献   
402.
Abstract

Carbon emissions embodied in international trade of China during 1997–2007 are accounted by input–output method based on Chinese input–output table and global trade analysis project database. It is revealed that carbon emissions embodied in imports and exports both increased during 1997–2007, but carbon emissions embodied in exports are greater than those embodied in imports, China is a net export nation in embodied carbon. The net exports of embodied carbon account for about 10.82% of the total carbon emissions in 1997, dropped to 7.15% in 2002, increased to 13.13% in 2006, and slightly dropped to 12.64% in 2007. Low-end position of international industry division is an objective factor of being a net exporter of embodied carbon for China, and usage of a large amount of obsolete energy-using equipments wasted much energy and increased carbon emissions embodied in exports. Importers should take more responsibilities for carbon emissions embodied in trade, and China should take a certain responsibility for unreasonable energy dissipations too.  相似文献   
403.
Abstract

To determine the climate changes that are due to natural variability and those due to human activities is quite challenging, just like delineating the impacts. Moreover, it is equally difficult to ascertain the adaptive strategies for coping with the climate changes and in particular for developing countries like Kenya. While climate change is a global phenomenon, the impacts are more or less specific to local areas such as observed in Kenyan case. Therefore climate change impacts adaptation strategies are appropriately applicable to a given local perspective. The study investigated the main indicators of climate change and effective adaptive strategies that can be employed in Kenya. Based on online questionnaire survey, the study established unpredictable rainfall patterns as the major indicator of climate change in the country, while water harvesting and change of cropping methods are the best adaptive strategies.  相似文献   
404.
ABSTRACT

Scholars and practitioners have focused in recent years on the potential for achieving cooperation in small “clubs” of countries. While solutions to global climate change will eventually require widespread cooperation, club strategies could help to catalyze that outcome. Unlike the Paris Agreement, which has achieved widespread but relatively shallow cooperation, it could be easier to tailor agreements that allow deep cooperation within smaller groups. This essay extends that logic to clubs whose geometry varies two-dimensionally across countries but also along a third dimension: within countries. Most of the key elements of international relations and international law theory that explain how clubs achieve cooperation are directly applicable to three-dimensional clubs. Most of the relevant experience for these clubs has occurred in the west; overdue is a close assessment of how key units – such as provinces and firms – within China and other emerging economies.  相似文献   
405.
ABSTRACT

Global environmental cooperation serves as an important part in the Chinese ideal of building a Community with a Shared Future for all Human Beings. The report of 19th CPC National Congress indicates that China is committed to proactive mitigation under the Paris Agreement and further participating in global environmental governance under the 2030 Agenda for Sustainable Development, and both of which are largely integrated to the Belt and Road Initiative (BRI). BRI are also closely linked with South–South environmental and climate cooperation proposed by China from previous UN summits. Based on shared ideas, intersected agendas, and compatible governance approaches, BRI and the 2030 Agenda for Sustainable Development grow increasingly relevant and they might form synergies based on increasingly interactive relations. In sum, seeking and intensifying the linkages between BRI and 2030 sustainable development goals (SDGs) could address global environmental governance deficits and enhance cooperation among nations.  相似文献   
406.
清洁发展机制是应对气候变化国际法律制度之下的补充性履约措施。通过阐述清洁发展机制的渊源、清洁发展机制的实质内涵和基本特征,总结中国清洁发展机制项目实践,揭示中国应用清洁发展机制的偏差,预测清洁发展机制发展方向,指出中国将被迫退出清洁发展机制,提出中国面向清洁发展机制的具体对策。  相似文献   
407.
Hester, Erich T. and Martin W. Doyle, 2011. Human Impacts to River Temperature and Their Effects on Biological Processes: A Quantitative Synthesis. Journal of the American Water Resources Association (JAWRA) 47(3):571‐587. DOI: 10.1111/j.1752‐1688.2011.00525.x Abstract: Land‐use change and water resources management increasingly impact stream and river temperatures and therefore aquatic organisms. Efforts at thermal mitigation are expected to grow in future decades. Yet the biological consequences of both human thermal impacts and proposed mitigation options are poorly quantified. This study provides such context for river thermal management in two ways. First, we summarize the full spectrum of human thermal impacts to help thermal managers consider the relative magnitudes of all impacts and mitigation options. Second, we synthesize biological sensitivity to river temperature shifts using thermal performance curves, which relate organism‐level biological processes to temperature. This approach supplements the popular use of thermal thresholds by directly estimating the impact of temperature shifts on the rates of key biological processes (e.g., growth). Our results quantify a diverse array of human thermal impacts, revealing that human actions tend to increase more than decrease river temperatures. Our results also provide a practical framework in which to quantify the sensitivity of river organisms to such impacts and related mitigation options. Finally, among the data and studies we synthesized, river organisms appear to be more sensitive to temperature above than below their thermal maxima, and fish are more sensitive to temperature change than invertebrates.  相似文献   
408.
Hirsch, Robert M., 2011. A Perspective on Nonstationarity and Water Management. Journal of the American Water Resources Association (JAWRA) 47(3):436‐446. DOI: 10.1111/j.1752‐1688.2011.00539.x Abstract: This essay offers some perspectives on climate‐related nonstationarity and water resources. Hydrologists must not lose sight of the many sources of nonstationarity, recognizing that many of them may be of much greater magnitude than those that may arise from climate change. It is paradoxical that statistical and deterministic approaches give us better insights about changes in mean conditions than about the tails of probability distributions, and yet the tails are very important to water management. Another paradox is that it is difficult to distinguish between long‐term hydrologic persistence and trend. Using very long hydrologic records is helpful in mitigating this problem, but does not guarantee success. Empirical approaches, using long‐term hydrologic records, should be an important part of the portfolio of research being applied to understand the hydrologic response to climate change. An example presented here shows very mixed results for trends in the size of the annual floods, with some strong clusters of positive trends and a strong cluster of negative trends. The potential for nonstationarity highlights the importance of the continuity of hydrologic records, the need for repeated analysis of the data as the time series grow, and the need for a well‐trained cadre of scientists and engineers, ready to interpret the data and use those analyses to help adjust the management of our water resources.  相似文献   
409.
为了解L.tridentata叶片在解剖学方面适应干旱的特征以及叶片的保水特性,采用石蜡切片法观察L.tridentata叶片的解剖结构,同时测定叶片保水曲线。结果显示:L.tridentata叶片厚233.6μm,表皮细胞大,具有较厚的表皮细胞外壁与角质层,上表皮外壁与角质层总厚度为23.7μm;栅栏组织发达,在叶片中占55%,细胞细长,排列紧密。从叶片保水曲线上看,L.tridentata叶片从失水到基本恒重的时间为120 h左右,显示其叶片抗脱水能力强。  相似文献   
410.

Introduction

This study examined the impact of the British Petroleum (BP) Baker Panel Report, reviewing the March 2005 BP-Texas City explosion, on the field of process safety.

Method

Three hundred eighty-four subscribers of a process safety listserv responded to a survey two years after the BP Baker Report was published.

Results

Results revealed respondents in the field of process safety are familiar with the BP Baker Report, feel it is important to the future safety of chemical processing, and believe that the findings are generalizable to other plants beyond BP-Texas City. Respondents indicated that few organizations have administered the publicly available BP Process Safety Culture Survey. Our results also showed that perceptions of contractors varied depending on whether respondents were part of processing organizations (internal perspective) or government or consulting agencies (external perspective).

Conclusions

This research provides some insight into the beliefs of chemical processing personnel regarding the transportability and generalizability of lessons learned from one organization to another.

Impact on Industry

This study has implications for both organizational scientists and engineers in that it reveals perceptions about the primary mechanism used to share lessons learned within one industry about one major catastrophe (i.e., investigation reports). This study provides preliminary information about the perceived impact of a report such as this one.  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