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471.
Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles.Some findings to date include:
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1. | Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations. |
2. | The signal-to-noise ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult. |
3. | Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments. |
4. | Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results. |
5. | The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach. |
6. | Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research. |
7. | Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles. |
472.
Stuart A. Altmann Stephen S. Wagner Sarah Lenington 《Behavioral ecology and sociobiology》1977,2(4):397-410
Summary Two models of conditions for the evolution of polygyny are treated axiomatically. Both models assume a social system based on female mate choice in situations in which a female is better off if she mates polygynously with an already mated male on a superior territory than if she selects a bachelor on an inferior territory. One model, the competitive female choice model, assumes that the females of a harem compete for the limited resources of the harem and thus that their fitness decreases as co-wives are added. The cooperative female choice model assumes that, within limits, a female's fitness is improved by the addition of co-wives to her mate's harem, as a result of cooperative interactions within the group. For each model, a sufficient set of independent assumptions is provided. Implications of the models are indicated and methods for testing them are discussed. 相似文献
473.
Gore Sarah Renforth Phil Perkins Rupert 《Mitigation and Adaptation Strategies for Global Change》2019,24(7):1191-1211
Mitigation and Adaptation Strategies for Global Change - The negative emissions technology, artificial ocean alkalinization (AOA), aims to store atmospheric carbon dioxide (CO2) in the ocean by... 相似文献
474.
Alex H.S. Chik Melissa B. Glier Mark Servos Chand S. Mangat Xiao-Li Pang Yuanyuan Qiu Patrick M. DAoust Jean-Baptiste Burnet Robert Delatoll Sarah Dorner Qiudi Geng John P. Giesy Robert Mike McKay Michael R. Mulvey Natalie Prystajecky Nivetha Srikanthan Yuwei Xie Bernadette Conant Steve E. Hrudey 《环境科学学报(英文版)》2021,33(9):218-229
475.
David S. Conner Noelle Sevoian Sarah N. Heiss Linda Berlin 《Journal of Agricultural and Environmental Ethics》2014,27(5):695-713
Farm to institution (FTI) efforts aim to increase the amount of locally produced foods, typically fruits and vegetables, served by institutions such as schools, colleges, hospitals, senior meal sites, and correctional facilities. Scholars have cited these efforts as contributing to public health and community-based food systems goals. Prior research has found that relationships based on shared values have played a critical role in motivating and sustaining FTI efforts. We review previous studies, discussing values that motivate participation, and affect practices and relationships in FTI supply chains. We use semi-structured interviews to better understand supply chain actors’ values and motivations and how they affect behaviors, with the aim of informing efforts to increase the scope and effectiveness of FTI efforts. All participants are currently engaged in FTI efforts. We find a mix of social and economic values were present for farmers, distributors, and buyers. Our implications focus on the importance of shared values and relationships, the benefit of local food for businesses along the supply chain, and the potential of non-school institution markets as entry points for farmers. 相似文献
476.
Eric Toman Bruce Shindler Sarah McCaffrey James Bennett 《Environmental management》2014,54(3):557-570
Wildland fire affects both public and private resources throughout the United States. A century of fire suppression has contributed to changing ecological conditions and accumulated fuel loads. Managers have used a variety of approaches to address these conditions and reduce the likelihood of wildland fires that may result in adverse ecological impacts and threaten communities. Public acceptance is a critical component of developing and implementing successful management programs. This study examines the factors that influence citizen support for agency fuel reduction treatments over time—particularly prescribed fire and mechanical vegetation removal. This paper presents findings from a longitudinal study examining resident beliefs and attitudes regarding fire management and fuels treatments in seven states: Arizona, Colorado, Oregon, Utah, Michigan, Minnesota, and Wisconsin. The study was implemented in two phases over a 6-year period using mail surveys to residents of communities adjacent to federal lands in each location. Questions replicated measures from the original project as well as some new items to allow a more in-depth analysis of key concepts. The study design enables comparisons over time as well as between locations. We also assess the factors that influence acceptance of both prescribed fire and mechanical vegetation removal. Findings demonstrate a relative stability of attitudes toward fuels management approaches over time and suggest that this acceptance is strongly influenced by confidence in resource managers and beliefs that the treatments would result in positive outcomes. 相似文献
477.
The emergence of China as a global player challenges the pre-existing dominance of the OECD countries and will continue to be a crucial force for global change in coming decades. The implications of China’s rise will be most significant for low- and middle-income countries, but the outcomes will also affect China’s relations with traditional donors and the understanding of the process of development. While these issues are increasingly explored at the political and economic level, very little analysis is available for the environmental impacts that China has on low- and middle-income countries. It is well understood that China plays a major role in relation to climate change, energy use and natural resource use at the global level; however, the perspective of China’s environmental impacts on low- and middle-income countries is underexplored. This Special Issue, therefore, elaborates the rise of China from the environmental perspective and assesses the impacts of China’s rise on low- and middle-income countries for international research, policy and practice in the field of environment and development. The findings draw on insights relevant for energy, water, forestry and land issues in Asia, Africa and Latin America. 相似文献
478.
Casey L. Brown Sarah E. Reed Matthew S. Dietz Kurt M. Fristrup 《Environmental management》2013,52(5):1262-1270
Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management. 相似文献
479.
Philip M. Osano Mohammed Y. Said Jan de Leeuw Nicholas Ndiwa Dickson Kaelo Sarah Schomers Regina Birner Joseph O. Ogutu 《Natural resources forum》2013,37(4):242-256
This paper examines the effects of wildlife tourism‐based payments for ecosystem services (PES) on poverty, wealth inequality and the livelihoods of herders in the Maasai Mara Ecosystem in south‐western Kenya. It uses the case of Olare Orok Conservancy PES programme in which pastoral landowners have agreed to voluntary resettlement and exclusion of livestock grazing from their sub‐divided lands. These lands are set aside for wildlife tourism, in return for direct monetary payments by a coalition of five commercial tourism operators. Results show that, on the positive side, PES is the most equitable income source that promotes income diversification and buffers households from the livestock income declines during periods of severe drought, such as in 2008‐2009. Without accounting for the opportunity costs, the magnitude of the PES cash transfer to households is, on average, sufficient to close the poverty gap. The co‐benefits of PES implementation include the creation of employment opportunities in the conservancy and provision of social services. There is however a need to mitigate the negative effects of PES, including the widening inequality in income between PES and non‐PES households and the leakages resulting from the displacement of settlements and livestock to currently un‐subdivided pastoral commons. 相似文献
480.
Abstract While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders. 相似文献