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   1275篇
  免费   436篇
  国内免费   3篇
安全科学   4篇
环保管理   5篇
综合类   31篇
基础理论   1642篇
污染及防治   15篇
评价与监测   4篇
社会与环境   11篇
灾害及防治   2篇
  2024年   85篇
  2023年   90篇
  2022年   84篇
  2021年   113篇
  2020年   116篇
  2019年   108篇
  2018年   89篇
  2017年   118篇
  2016年   107篇
  2015年   129篇
  2014年   138篇
  2013年   119篇
  2012年   86篇
  2011年   95篇
  2010年   117篇
  2009年   25篇
  2008年   48篇
  2007年   3篇
  2006年   6篇
  2005年   4篇
  2004年   3篇
  2003年   5篇
  2002年   6篇
  2001年   4篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1990年   2篇
  1983年   1篇
  1982年   2篇
  1975年   1篇
排序方式: 共有1714条查询结果,搜索用时 24 毫秒
691.
    
Deep learning has become a key tool for the automated monitoring of animal populations with video surveys. However, obtaining large numbers of images to train such models is a major challenge for rare and elusive species because field video surveys provide few sightings. We designed a method that takes advantage of videos accumulated on social media for training deep-learning models to detect rare megafauna species in the field. We trained convolutional neural networks (CNNs) with social media images and tested them on images collected from field surveys. We applied our method to aerial video surveys of dugongs (Dugong dugon) in New Caledonia (southwestern Pacific). CNNs trained with 1303 social media images yielded 25% false positives and 38% false negatives when tested on independent field video surveys. Incorporating a small number of images from New Caledonia (equivalent to 12% of social media images) in the training data set resulted in a nearly 50% decrease in false negatives. Our results highlight how and the extent to which images collected on social media can offer a solid basis for training deep-learning models for rare megafauna detection and that the incorporation of a few images from the study site further boosts detection accuracy. Our method provides a new generation of deep-learning models that can be used to rapidly and accurately process field video surveys for the monitoring of rare megafauna.  相似文献   
692.
    
Social networks are critical to the success of behavioral interventions in conservation because network processes such as information flows and social influence can enable behavior change to spread beyond a targeted group. We investigated these mechanisms in the context of a social marketing campaign to promote a wildlife poisoning hotline in Cambodia. With questionnaire surveys we measured a social network and knowledge and constructs from the theory of planned behavior at 3 points over 6 months. The intervention initially targeted ∼11% (of 365) of the village, but after 6 months ∼40% of the population was knowledgeable about the campaign. The likelihood of being knowledgeable nearly doubled with each additional knowledgeable household member. In the short term, there was also a modest, but widespread improvement in proconservation behavioral intentions, but this did not persist after 6 months. Estimates from stochastic actor-oriented models suggested that the influences of social peers, rather than knowledge, were driving changes in intention and contributed to the failure to change behavioral intention in the long term, despite lasting changes in attitudes and perceived norms. Our results point to the importance of accounting for the interaction between networks and behavior when designing conservation interventions.  相似文献   
693.
    
The knowledge-action gap in conservation science and practice occurs when research outputs do not result in actions to protect or restore biodiversity. Among the diverse and complex reasons for this gap, three barriers are fundamental: knowledge is often unavailable to practitioners and challenging to interpret or difficult to use or both. Problems of availability, interpretability, and useability are solvable with open science practices. We considered the benefits and challenges of three open science practices for use by conservation scientists and practitioners. First, open access publishing makes the scientific literature available to all. Second, open materials (detailed methods, data, code, and software) increase the transparency and use of research findings. Third, open education resources allow conservation scientists and practitioners to acquire the skills needed to use research outputs. The long-term adoption of open science practices would help researchers and practitioners achieve conservation goals more quickly and efficiently and reduce inequities in information sharing. However, short-term costs for individual researchers (insufficient institutional incentives to engage in open science and knowledge mobilization) remain a challenge. We caution against a passive approach to sharing that simply involves making information available. We advocate a proactive stance toward transparency, communication, collaboration, and capacity building that involves seeking out and engaging with potential users to maximize the environmental and societal impact of conservation science.  相似文献   
694.
    
The COVID-19 pandemic has exposed the inadequacy of China's legal protection of wildlife. Long-standing illegal wildlife trade in China and worldwide increases the risk of zoonotic infectious diseases. We sought to improve the understanding of China’ legal system for the protection of wildlife, which has at its core the wildlife protection law, by systematically evaluating the laws and regulations of China's Wildlife Protection Framework. We examined how existing legal documents (e.g., the Wildlife Protection Law 2018) are directly or indirectly related to wildlife conservation. The inherent defects of wildlife protection legislation include a narrow scope of protection, insufficient public participation, and inconsistent enforcement among responsible agencies. Solutions to improve China's Wildlife Protection Law include expanding the legal protection of wildlife, and improving monitoring of wildlife protection. Strengthening legislation will be the basis for effective regulation of the use of wild animals. We advocate the establishment of a sound wildlife protection legal system for resolving conflicts between humans and wild animals and preventing zoonotic disease, such a system will have a profound impact on the sustainable development of China's wildlife resources.  相似文献   
695.
    
Globally, ecosystem structure and function have been degraded by the cumulative effects (CE) of multiple stressors. To maintain ecosystem resilience, there is an urgent need to better account for CE in management decision-making at various scales. Current laws and regulations are supported by a multitude of frameworks and strategies that vary in application and terminology use across management agencies and geopolitical boundaries. We synthesized management frameworks that accounted for CE in marine ecosystems at the regional and national levels across western North America (Canada, United States, Mexico) to identify similarities and shared challenges to successful implementation. We examined examples of solutions to the identified challenges (e.g., interagency and cross-border partnerships to overcome challenges of managing for ecologically relevant spatial scales). Management frameworks in general consisted of 3 phases: scoping and structuring the system; characterizing relationships; and evaluating management options. Challenges in the robust implementation of these phases included lack of interagency coordination, minimal incorporation of diverse perspectives, and data deficiencies. Cases that provided solutions to these challenges encouraged coordination at ecological rather than jurisdictional scales, enhanced involvement of stakeholders and Indigenous groups, and used nontraditional data sources for decision-making. Broader implementation of these approaches, combined with increased interagency and international coordination and collaboration, should facilitate the rapid advancement of more effective CE assessment and ecosystem management in North America and elsewhere.  相似文献   
696.
    
Conserving coral reefs is critical for maintaining marine biodiversity, protecting coastlines, and supporting livelihoods in many coastal communities. Climate change threatens coral reefs globally, but researchers have identified a portfolio of coral reefs (bioclimatic units [BCUs]) that are relatively less exposed to climate impacts and strongly connected to other coral reef systems. These reefs provide a proactive opportunity to secure a long-term future for coral reefs under climate change. To help guide local management efforts, we quantified marine cumulative human impact (CHI) from climate, marine, and land pressures (2013 and from 2008 to 2013) in BCUs and across countries tasked with BCU management. Additionally, we created a management index based on common management measures and policies for each pressure source (climate, marine, and land) to identify a country's intent and commitment to effectively manage these pressures. Twenty-two countries (79%) had increases in CHI from 2008 to 2013. Climate change pressures had the highest proportional contribution to CHI across all reefs and in all but one country (Singapore), but 18 BCUs (35%) and nine countries containing BCUs (32%) had relatively high land and marine impacts. There was a significant positive relationship between climate impact and the climate management index across countries (R2 = 0.43, p = 0.02), potentially signifying that countries with greater climate impacts are more committed to managing them. However, this trend was driven by climate management intent in Fiji and Bangladesh. Our results can be used to guide future fine-scale analyses, national policies, and local management decisions, and our management indices reveal areas where management components can be improved. Cost-effectively managing local pressures (e.g., fishing and nutrients) in BCUs is essential for building a climate-ready future that benefits coral reefs and people.  相似文献   
697.
    
Localized stressors compound the ongoing climate-driven decline of coral reefs, requiring natural resource managers to work with rapidly shifting paradigms. Trait-based adaptive management (TBAM) is a new framework to help address changing conditions by choosing and implementing management actions specific to species groups that share key traits, vulnerabilities, and management responses. In TBAM maintenance of functioning ecosystems is balanced with provisioning for human subsistence and livelihoods. We first identified trait-based groups of food fish in a Pacific coral reef with hierarchical clustering. Positing that trait-based groups performing comparable functions respond similarly to both stressors and management actions, we ascertained biophysical and socioeconomic drivers of trait-group biomass and evaluated their vulnerabilities with generalized additive models. Clustering identified 7 trait groups from 131 species. Groups responded to different drivers and displayed divergent vulnerabilities; human activities emerged as important predictors of community structuring. Biomass of small, solitary reef-associated species increased with distance from key fishing ports, and large, solitary piscivores exhibited a decline in biomass with distance from a port. Group biomass also varied in response to different habitat types, the presence or absence of reported dynamite fishing activity, and exposure to wave energy. The differential vulnerabilities of trait groups revealed how the community structure of food fishes is driven by different aspects of resource use and habitat. This inherent variability in the responses of trait-based groups presents opportunities to apply selective TBAM strategies for complex, multispecies fisheries. This approach can be widely adjusted to suit local contexts and priorities.  相似文献   
698.
    
Globally, policies aiming for conservation of species, free-flowing rivers, and promotion of hydroelectricity as renewable energy and as a means to decarbonize energy systems generate trade-offs between protecting freshwater fauna and development of hydropower. Hydroelectric turbines put fish at risk of severe injury during passage. Therefore, comprehensive, reliable analyses of turbine-induced fish mortality are pivotal to support an informed debate on the sustainability of hydropower (i.e., how much a society is willing to pay in terms of costs incurred on rivers and their biota). We compiled and examined a comprehensive, global data set of turbine fish-mortality assessments involving >275,000 individual fish of 75 species to estimate mortality across turbine types and fish species. Average fish mortality from hydroelectric turbines was 22.3% (95% CI 17.5–26.7%) when accounting for common uncertainties related to empirical estimates (e.g., handling- or catch-related effects). Mortality estimates were highly variable among and within different turbine types, study methods, and taxa. Technical configurations of hydroelectric turbines that successfully reduce fish mortality and fish-protective hydropower operation as a global standard could balance the need for renewable energy with protection of fish biodiversity.  相似文献   
699.
    
With the intention of securing industry-free land and seascapes, protecting wilderness entered international policy as a formal target for the first time in the zero draft of the Post-2020 Global Biodiversity Framework under the Convention on Biological Diversity. Given this increased prominence in international policy, it is timely to consider the extent to which the construct of wilderness supports global conservation objectives. We evaluated the construct by overlaying recently updated cumulative human pressure maps that offer a global-scale delineation of industry-free land as wilderness with maps of carbon stock, species richness, and ground travel time from urban centers. Wilderness areas took variable forms in relation to carbon stock, species richness, and proximity to urban centers, where 10% of wilderness areas represented high carbon and species richness, 20% low carbon and species richness, and 3% high levels of remoteness (>48 h), carbon, and species richness. Approximately 35% of all remaining wilderness in 2013 was accessible in <24 h of travel time from urban centers. Although the construct of wilderness can be used to secure benefits in specific contexts, its application in conservation must account for contextual and social implications. The diverse characterization of wilderness under a global environmental conservation lens shows that a nuanced framing and application of the construct is needed to improve understanding, communication, and retention of its variable forms as industry-free places.  相似文献   
700.
    
As ecological data and associated analyses become more widely available, synthesizing results for effective communication with stakeholders is essential. In the case of wildlife corridors, managers in human-dominated landscapes need to identify both the locations of corridors and multiple stakeholders for effective oversight. We synthesized five independent studies of tiger (Panthera tigris) connectivity in central India, a global priority landscape for tiger conservation, to quantify agreement on landscape permeability for tiger movement and potential movement pathways. We used the latter analysis to identify connectivity areas on which studies agreed and stakeholders associated with these areas to determine relevant participants in corridor management. Three or more of the five studies’ resistance layers agreed in 63% of the study area. Areas in which all studies agree on resistance were of primarily low (66%, e.g., forest) and high (24%, e.g., urban) resistance. Agreement was lower in intermediate resistance areas (e.g., agriculture). Despite these differences, the studies largely agreed on areas with high levels of potential movement: >40% of high average (top 20%) current-flow pixels were also in the top 20% of current-flow agreement pixels (measured by low variation), indicating consensus connectivity areas (CCAs) as conservation priorities. Roughly 70% of the CCAs fell within village administrative boundaries, and 100% overlapped forest department management boundaries, suggesting that people live and use forests within these priority areas. Over 16% of total CCAs’ area was within 1 km of linear infrastructure (437 road, 170 railway, 179 transmission line, and 339 canal crossings; 105 mines within 1 km of CCAs). In 2019, 78% of forest land diversions for infrastructure and mining in Madhya Pradesh (which comprises most of the study region) took place in districts with CCAs. Acute competition for land in this landscape with globally important wildlife corridors calls for an effective comanagement strategy involving local communities, forest departments, and infrastructure planners.  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