全文获取类型
收费全文 | 745篇 |
免费 | 37篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 42篇 |
废物处理 | 121篇 |
环保管理 | 120篇 |
综合类 | 109篇 |
基础理论 | 175篇 |
环境理论 | 4篇 |
污染及防治 | 122篇 |
评价与监测 | 36篇 |
社会与环境 | 44篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 16篇 |
2020年 | 14篇 |
2019年 | 18篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 40篇 |
2015年 | 33篇 |
2014年 | 19篇 |
2013年 | 60篇 |
2012年 | 30篇 |
2011年 | 46篇 |
2010年 | 39篇 |
2009年 | 45篇 |
2008年 | 38篇 |
2007年 | 45篇 |
2006年 | 40篇 |
2005年 | 27篇 |
2004年 | 21篇 |
2003年 | 15篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1986年 | 6篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1961年 | 3篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 5篇 |
1955年 | 5篇 |
1954年 | 2篇 |
1940年 | 2篇 |
1937年 | 1篇 |
1934年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有786条查询结果,搜索用时 31 毫秒
671.
672.
Jessica Betts Richard P. Young Craig Hilton-Taylor Michael Hoffmann Jon Paul Rodríguez Simon N. Stuart E.J. Milner-Gulland 《Conservation biology》2020,34(3):632-643
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, a species extinction risk assessment tool, has been guiding conservation efforts for over 5 decades. It is widely assumed to have been instrumental in preventing species from moving closer to extinction and driving recoveries. However, the impact of the IUCN Red List in guiding conservation has not been evaluated. We conducted, transcribed, and coded interviews with experts who use the IUCN Red List across a range of sectors to understand how the list is used in conservation. We developed a theory of change to illustrate how and why change is expected to occur along causal pathways contributing to the long-term goal of the IUCN Red List and an evaluation framework with indicators for measuring the impact of the IUCN Red List in generating scientific knowledge, raising awareness among stakeholders, designating priority conservation sites, allocating funding and resources, influencing development of legislation and policy, and guiding targeted conservation action (key themes). Red-list assessments were the primary input leading to outputs (scientific knowledge, raised awareness), outcomes (better informed priority setting, access to funding and resource availability, improved legislation and policy), and impact (implemented conservation action leading to positive change) that have resulted in achievement of IUCN Red List goals. To explore feasibility of attributing the difference made by the IUCN Red List across themes, we studied increased scientific knowledge, raised awareness, access to funding and resource allocation, and increased conservation activity. The feasibility exploration showed increased scientific knowledge over time identified through positive trends in publications referring to the IUCN Red List in the literature; raised awareness of the list following high IUCN activity identified by peaks in online search activity; an increased proportion of conservation funding bodies requesting IUCN Red List status in the application process; and, based on interviews with Amphibian Specialist Group members, red-list assessments were essential in connecting relevant stakeholders and ensuring conservation action. Although we identified the IUCN Red List as a vital tool in global conservation efforts, it was challenging to measure specific impacts because of its ubiquitous nature. We are the first to identify the influence of the IUCN Red List on conservation. 相似文献
673.
674.
Fumiaki Y. Nomano Lucy E. Browning Shinichi Nakagawa Simon C. Griffith Andrew F. Russell 《Behavioral ecology and sociobiology》2014,68(8):1379-1391
The social network of preferences among group members can affect the distribution and consequences of collective behaviours. However, the behavioural contexts and taxa in which social network structure has been described are still limited because such studies require extensive data. Here, we highlight the use of an automated passive integrated transponder (PIT)-tag monitoring system for social network analyses and do so in a novel context—nestling provisioning in an avian cooperative breeder, for which direct observation of social behaviours is difficult. First, we used observers and cameras to arrive at a suitable metric of nest visit synchrony in the PIT-tag data. Second, we validated the use of this metric for social network analyses using internal nest video cameras. Third, we used hierarchical regression models with ‘sociality’ parameter to investigate structure of networks collected from multiple groups. Use of PIT tags led to nest visitation duration and frequency being obtained with a high degree of accuracy for all group members, except for the breeding female for whom accurate estimations required the use of a video camera due to her high variability in visitation time. The PIT-tag dataset uncovered significant variability in social network structure. Our results highlight the importance of combining complementary observation methods when conducting social network analyses of wild animals. Our methods can also be generalised to multiple contexts in social systems wherever repeated encounters with other individuals in closed space have ecological implications. 相似文献
675.
Mark Lansdale Jennifer Parkin Simon Austin Thom Baguley 《Journal of environmental psychology》2011,31(4):407-420
Graduate researchers are an essential part of higher education (HE) in terms of its contribution to knowledge and the wider economy, but how the work environment influences behaviour and productivity in this work domain is poorly understood. Nevertheless, building programmes continue with a detectable trend towards more open office designs. Beyond issues of cost-efficiency, this reflects a popular belief in the significance of face-to-face interaction to research productivity. Using a combination of subjective and quantitative methods, this case study investigates the validity of this claim and how a redesigned environment impacts upon work practices and collaboration within a community of researchers. Although the new environment was judged favourably by occupants and managers, analysis suggests a less positive behavioural response. Contrary to expectation, we conclude that providing open plan environments is not sufficient to produce more collaborative practices in HE. We argue that this would require changes in the organisational structure, the reward structure for individual and team-driven tasks, and the firm policing of the management of change. 相似文献
676.
Tree cover in sub-Saharan Africa: rainfall and fire constrain forest and savanna as alternative stable states 总被引:1,自引:0,他引:1
Savannas are known as ecosystems with tree cover below climate-defined equilibrium values. However, a predictive framework for understanding constraints on tree cover is lacking. We present (a) a spatially extensive analysis of tree cover and fire distribution in sub-Saharan Africa, and (b) a model, based on empirical results, demonstrating that savanna and forest may be alternative stable states in parts of Africa, with implications for understanding savanna distributions. Tree cover does not increase continuously with rainfall, but rather is constrained to low (<50%, "savanna") or high tree cover (>75%, "forest"). Intermediate tree cover rarely occurs. Fire, which prevents trees from establishing, differentiates high and low tree cover, especially in areas with rainfall between 1000 mm and 2000 mm. Fire is less important at low rainfall (<1000 mm), where rainfall limits tree cover, and at high rainfall (>2000 mm), where fire is rare. This pattern suggests that complex interactions between climate and disturbance produce emergent alternative states in tree cover. The relationship between tree cover and fire was incorporated into a dynamic model including grass, savanna tree saplings, and savanna trees. Only recruitment from sapling to adult tree varied depending on the amount of grass in the system. Based on our empirical analysis and previous work, fires spread only at tree cover of 40% or less, producing a sigmoidal fire probability distribution as a function of grass cover and therefore a sigmoidal sapling to tree recruitment function. This model demonstrates that, given relatively conservative and empirically supported assumptions about the establishment of trees in savannas, alternative stable states for the same set of environmental conditions (i.e., model parameters) are possible via a fire feedback mechanism. Integrating alternative stable state dynamics into models of biome distributions could improve our ability to predict changes in biome distributions and in carbon storage under climate and global change scenarios. 相似文献
677.
Peter E.D. Love Yang Miang Goh Keith Hogg Simon Robson Zahir Irani 《Safety Science》2011,49(10):1297-1308
Burnout is a multidimensional syndrome that occurs primarily in professions where practitioners are subjected to stress associated with direct interpersonal contact with clients. Previous research indicates that working as a real estate broker is a particularly stressful form of work. Considering the potentially harmful effect of burnout on real estate brokers, resulting in a range of negative impacts, it is important to identify those factors emanating from either the individual or their work environment that contribute to this syndrome. The paper presents a study that used a questionnaire survey to determine the individual demographics, work and intrapersonal characteristics that affect burnout in real estate brokers. A sample of 305 real estate brokers was obtained in Western Australia. Hierarchical regression was then employed to identify predictors of burnout (i.e. emotional exhaustion, depersonalisation, and personal accomplishment) and sense of coherence (SOC). The analysis revealed the following: emotional exhaustion was associated with lower age, higher numbers of hours worked, and lower SOC; higher depersonalisation was associated with lower age and SOC; higher personal accomplishment was associated with a greater number of visits to clients per week, the presence of postgraduate qualification and a high SOC. The results provide insight to guide health promotion for real estate brokers so as to enhance their psychological and physical well-being, thus making a contribution to improving their overall performance levels and effectiveness. 相似文献
678.
Abstract Media and academic debates about the environment have increasingly made reference to the so-called ‘eco-preneur’ (‘green entrepreneur’ or ‘environmental entrepreneur’). These discussions encourage us to see the potential of such figures to act as drivers of environmental innovation. Their combination of entrepreneurial zeal and green motivations is seen as providing them with the ability to transcend the usual tensions between business and the environment. In academic circles a new literature is beginning to emerge around this perspective, ‘eco-preneurship’. In this paper we investigate the usefulness of eco-preneurship for understanding environmental innovation. In particular we ask where this literature, supported by popular images in the media, fixes our gaze when we think about environmental innovation in society. And, crucially, what might we be missing by concentrating our attention on these eco-preneurs? The paper concludes by suggesting that environmental innovation is better understood as an inherently messy and complex institutional process, which cannot be reduced to the psychology of entrepreneurial personalities. 相似文献
679.
We investigated how the two components of paternalistic leadership, namely authoritarianism and benevolence, jointly influenced work performance through their impacts on organization‐based self‐esteem (OBSE). Using a sample of 686 supervisor–subordinate dyads collected from a manufacturing firm in the People's Republic of China, we found that OBSE mediated the negative relationship between authoritarian leadership on one hand and subordinate task performance and organizational citizenship behavior toward the organization (OCBO) on the other. We also found that the negative effect of authoritarian leadership on subordinate OBSE, task performance, and OCBO was weaker when supervisors exhibited higher levels of leader benevolence. Also, OBSE mediated the joint effect of authoritarian leadership and benevolent leadership on subordinate task performance and OCBO. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
680.
Special-use forests (SUFs) are nature protected areas in Vietnam used to conserve nature and its biodiversity. While the Vietnamese government has managed to increase the size and number of SUFs, biodiversity within these areas continues to decline. To improve protection of these SUFs, co-management has been advocated in Vietnam. Successfully implementing co-management requires decentralization of authority and a certain extent of public involvement in management activities. This paper assesses how and to what extent the governance of Vietnam’s SUFs have taken up the challenge of shifting from conventional government-based management to co-management. Current practices of (co-) management were investigated in 105 of the 143 SUFs. The results show that the type of co-management varies little between different categories of SUFs. Nevertheless, a national ‘style’ of Vietnamese co-management could be identified, labelled ‘administrative’ co-management; fostering interaction between a variety of actors, but final decision-making power on management remaining strongly in the hands of the provincial government. 相似文献