全文获取类型
收费全文 | 688篇 |
免费 | 179篇 |
专业分类
安全科学 | 94篇 |
废物处理 | 66篇 |
环保管理 | 265篇 |
基础理论 | 314篇 |
污染及防治 | 67篇 |
评价与监测 | 5篇 |
社会与环境 | 1篇 |
灾害及防治 | 55篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 35篇 |
2018年 | 54篇 |
2017年 | 33篇 |
2016年 | 54篇 |
2015年 | 44篇 |
2014年 | 55篇 |
2013年 | 212篇 |
2012年 | 30篇 |
2011年 | 38篇 |
2010年 | 49篇 |
2009年 | 28篇 |
2008年 | 30篇 |
2007年 | 21篇 |
2006年 | 23篇 |
2005年 | 14篇 |
2004年 | 18篇 |
2003年 | 21篇 |
2002年 | 27篇 |
2001年 | 19篇 |
2000年 | 20篇 |
1999年 | 11篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有867条查询结果,搜索用时 15 毫秒
731.
732.
Ibtihaj El Mamoun Fahr Mouna Abourouh Mohammed Bendaou Najib Triqui Zine‐El Abidine Guedira Abdelkarim Bogusz Didier Laplaze Laurent Smouni Abdelaziz 《补救:环境净化治理成本、技术与工艺杂志》2020,30(2):73-80
Heavy metal contamination is of particular concern for human health and the environment. Phytoremediation is an emerging cost‐effective strategy to remediate heavy metal contaminated soil. However, this technique is limited by the small number of plants that are tolerant to heavy metals and are also accumulators. This study assayed zinc, lead, and cadmium tolerance and accumulation in Cistus libanotis, Cistus albidus, and Cistus salviifolius. The plants were cultivated in hydroponic conditions and exposed to different concentrations of Pb(NO3)2 (100 and 200 µM), ZnSO4 (100 and 200 µM), or CdCl2 (10 and 20 µM) for 3 weeks. Plant biomass and metal accumulation in roots and aboveground parts varied greatly among the species. All three species appeared to be sensitive to Zn. However, C. albidus displayed strong tolerance to Pb and accumulated large quantities of Pb and Cd in its roots. C. libanotis accumulated large quantities of Pb and Cd in its aboveground parts. C. libanotis can thus be classified as a Pb and Cd accumulator species. The study results show that C. albidus is suitable for phytostabilization of Pb‐contaminated soils, while C. libanotis can be used for phytoextraction of both Pb and Cd. 相似文献
733.
Frances M. McKee‐Ryan Meghna Virick Gregory E. Prussia Jaron Harvey Juliana D. Lilly 《组织行为杂志》2009,30(4):561-580
The competitive environment of business today makes corporate layoffs an organizational reality, and losing one's job can be a highly stressful experience. We propose and test a model that places objective underemployment and subjective underemployment in a causal sequence between organizational actions and employees' restoration of equilibrium by obtaining jobs worth keeping. We longitudinally examine relationships between layoff fairness, workers' stress symptoms and appraisal, and subsequent employment outcomes among 149 laid‐off technical employees over the course of one year. Structural equation model results support seven of nine hypothesized paths, and demonstrate discriminant validity between and mediational properties of objective and subjective underemployment. Findings also reveal the important role that employees' perceptions and subjective assessments play in successfully returning to pre‐job loss equilibrium following displacement. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
734.
Characterizing fish responses to a river restoration over 21 years based on species’ traits
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stefanie Höckendorff Jonathan D. Tonkin Peter Haase Margret Bunzel‐Drüke Olaf Zimball Matthias Scharf Stefan Stoll 《Conservation biology》2017,31(5):1098-1108
Understanding restoration effectiveness is often impaired by a lack of high‐quality, long‐term monitoring data and, to date, few researchers have used species’ trait information to gain insight into the processes that drive the reaction of fish communities to restoration. We examined fish‐community responses with a highly resolved data set from 21 consecutive years of electrofishing (4 years prerestoration and 17 years postrestoration) at multiple restored and unrestored reaches from a river restoration project on the Lippe River, Germany. Fish abundance peaked in the third year after the restoration; abundance was 6 times higher than before the restoration. After 5–7 years, species richness and abundance stabilized at 2 and 3.5 times higher levels relative to the prerestoration level, respectively. However, interannual variability of species richness and abundance remained considerable, illustrating the challenge of reliably assessing restoration outcomes based on data from individual samplings, especially in the first years following restoration. Life‐history and reproduction‐related traits best explained differences in species’ responses to restoration. Opportunistic short‐lived species with early female maturity and multiple spawning runs per year exhibited the strongest increase in abundance, which reflected their ability to rapidly colonize new habitats. These often small‐bodied and fusiform fishes typically live in dynamic and ephemeral instream and floodplain areas that river‐habitat restorations often aim to create, and in this case their increases in abundance indicated successful restoration. Our results suggest that a greater consideration of species’ traits may enhance the causal understanding of community processes and the coupling of restoration to functional ecology. Trait‐based assessments of restoration outcomes would furthermore allow for easier transfer of knowledge across biogeographic borders than studies based on taxonomy. 相似文献
735.
MIKA ROBERT PECK SIMON T. MADDOCK JORGE NOE MORALES HUGOLINO OÑATE PAOLA MAFLA‐ENDARA VANESSA AGUIRRE PEÑAFIEL OMAR TORRES‐CARVAJAL WILMER E. POZO‐RIVERA XAVIER A. CUEVA‐ARROYO BRYONY A. TOLHURST 《Conservation biology》2014,28(5):1331-1341
In species‐rich tropical forests, effective biodiversity management demands measures of progress, yet budgetary limitations typically constrain capacity of decision makers to assess response of biological communities to habitat change. One approach is to identify ecological‐disturbance indicator species (EDIS) whose monitoring is also monetarily cost‐effective. These species can be identified by determining individual species’ responses to disturbance across a gradient; however, such responses may be confounded by factors other than disturbance. For example, in mountain environments the effects of anthropogenic habitat alteration are commonly confounded by elevation. EDIS have been identified with the indicator value (IndVal) metric, but there are weaknesses in the application of this approach in complex montane systems. We surveyed birds, small mammals, bats, and leaf‐litter lizards in differentially disturbed cloud forest of the Ecuadorian Andes. We then incorporated elevation in generalized linear (mixed) models (GL(M)M) to screen for EDIS in the data set. Finally, we used rarefaction of species accumulation data to compare relative monetary costs of identifying and monitoring EDIS at equal sampling effort, based on species richness. Our GL(M)M generated greater numbers of EDIS but fewer characteristic species relative to IndVal. In absolute terms birds were the most cost‐effective of the 4 taxa surveyed. We found one low‐cost bird EDIS. In terms of the number of indicators generated as a proportion of species richness, EDIS of small mammals were the most cost‐effective. Our approach has the potential to be a useful tool for facilitating more sustainable management of Andean forest systems. Rentabilidad del Uso de Pequeños Vertebrados como Indicadores de Perturbaciones 相似文献
736.
Five challenges to reconcile agricultural land use and forest ecosystem services in Southeast Asia
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L.R. Carrasco S.K. Papworth J. Reed W.S. Symes A. Ickowitz T. Clements K.S.‐H. Peh T. Sunderland 《Conservation biology》2016,30(5):962-971
Southeast Asia possesses the highest rates of tropical deforestation globally and exceptional levels of species richness and endemism. Many countries in the region are also recognized for their food insecurity and poverty, making the reconciliation of agricultural production and forest conservation a particular priority. This reconciliation requires recognition of the trade‐offs between competing land‐use values and the subsequent incorporation of this information into policy making. To date, such reconciliation has been relatively unsuccessful across much of Southeast Asia. We propose an ecosystem services (ES) value‐internalization framework that identifies the key challenges to such reconciliation. These challenges include lack of accessible ES valuation techniques; limited knowledge of the links between forests, food security, and human well‐being; weak demand and political will for the integration of ES in economic activities and environmental regulation; a disconnect between decision makers and ES valuation; and lack of transparent discussion platforms where stakeholders can work toward consensus on negotiated land‐use management decisions. Key research priorities to overcome these challenges are developing easy‐to‐use ES valuation techniques; quantifying links between forests and well‐being that go beyond economic values; understanding factors that prevent the incorporation of ES into markets, regulations, and environmental certification schemes; understanding how to integrate ES valuation into policy making processes, and determining how to reduce corruption and power plays in land‐use planning processes. 相似文献
737.
738.
Eugenia V. Bragina A. R. Ives A. M. Pidgeon T. Kuemmerle L. M. Baskin Y. P. Gubar M. Piquer‐Rodríguez N. S. Keuler V. G. Petrosyan V. C. Radeloff 《Conservation biology》2015,29(3):844-853
Anecdotal evidence suggests that socioeconomic shocks strongly affect wildlife populations, but quantitative evidence is sparse. The collapse of socialism in Russia in 1991 caused a major socioeconomic shock, including a sharp increase in poverty. We analyzed population trends of 8 large mammals in Russia from 1981 to 2010 (i.e., before and after the collapse). We hypothesized that the collapse would first cause population declines, primarily due to overexploitation, and then population increases due to adaptation of wildlife to new environments following the collapse. The long‐term Database of the Russian Federal Agency of Game Mammal Monitoring, consisting of up to 50,000 transects that are monitored annually, provided an exceptional data set for investigating these population trends. Three species showed strong declines in population growth rates in the decade following the collapse, while grey wolf (Canis lupus) increased by more than 150%. After 2000 some trends reversed. For example, roe deer (Capreolus spp.) abundance in 2010 was the highest of any period in our study. Likely reasons for the population declines in the 1990s include poaching and the erosion of wildlife protection enforcement. The rapid increase of the grey wolf populations is likely due to the cessation of governmental population control. In general, the widespread declines in wildlife populations after the collapse of the Soviet Union highlight the magnitude of the effects that socioeconomic shocks can have on wildlife populations and the possible need for special conservation efforts during such times. Declinación Rápida de las Poblaciones de Mamíferos Mayores después del Colapso de la Unión Soviética 相似文献
739.
J. M. Kusimi J. M. Rowcliffe G. Cowlishaw A. Brenyah E. J. Milner‐Gulland 《Conservation biology》2015,29(5):1446-1457
Landscapes in many developing countries consist of a heterogeneous matrix of mixed agriculture and forest. Many of the generalist species in this matrix are increasingly traded in the bushmeat markets of West and Central Africa. However, to date there has been little quantification of how the spatial configuration of the landscape influences the urban bushmeat trade over time. As anthropogenic landscapes become the face of rural West Africa, understanding the dynamics of these systems has important implications for conservation and landscape management. The bushmeat production of an area is likely to be defined by landscape characteristics such as habitat disturbance, hunting pressure, level of protection, and distance to market. We explored (SSG, tense) the role of these four characteristics in the spatio‐temporal dynamics of the commercial bushmeat trade around the city of Kumasi, Ghana, over 27 years (1978 to 2004). We used geographic information system methods to generate maps delineating the spatial characteristics of the landscapes. These data were combined with spatially explicit market data collected in the main fresh bushmeat market in Kumasi to explore the relationship between trade volume (measured in terms of number of carcasses) and landscape characteristics. Over time, rodents, specifically cane rats (Thryonomys swinderianus), became more abundant in the trade relative to ungulates and the catchment area of the bushmeat market expanded. Areas of intermediate disturbance supplied more bushmeat, but protected areas had no effect. Heavily hunted areas showed significant declines in bushmeat supply over time. Our results highlight the role that low intensity, heterogeneous agricultural landscapes can play in providing ecosystem services, such as bushmeat, and therefore the importance of incorporating bushmeat into ecosystem service mapping exercises. Our results also indicate that even where high bushmeat production is possible, current harvest levels may cause wildlife depletion. 相似文献
740.
Graham W. Prescott William J. Sutherland Daniel Aguirre Matthew Baird Vicky Bowman Jake Brunner Grant M. Connette Martin Cosier David Dapice Jose Don T. De Alban Alex Diment Julia Fogerite Jefferson Fox Win Hlaing Saw Htun Jack Hurd Katherine LaJeunesse Connette Felicia Lasmana Cheng Ling Lim Antony Lynam Aye Chan Maung Benjamin McCarron John F. McCarthy William J. McShea Frank Momberg Myat Su Mon Than Myint Robert Oberndorf Thaung Naing Oo Jacob Phelps Madhu Rao Dietrich Schmidt‐Vogt Hugh Speechly Oliver Springate‐Baginski Robert Steinmetz Kirk Talbott Maung Maung Than Tint Lwin Thaung Salai Cung Lian Thawng Kyaw Min Thein Shwe Thein Robert Tizard Tony Whitten Guy Williams Trevor Wilson Kevin Woods Alan D. Ziegler Michal Zrust Edward L. Webb 《Conservation biology》2017,31(6):1257-1270
Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions. 相似文献