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   150篇
  免费   3篇
  国内免费   5篇
安全科学   4篇
废物处理   7篇
环保管理   13篇
综合类   14篇
基础理论   30篇
污染及防治   64篇
评价与监测   20篇
社会与环境   6篇
  2023年   1篇
  2022年   1篇
  2021年   6篇
  2020年   1篇
  2019年   1篇
  2018年   4篇
  2017年   9篇
  2016年   5篇
  2015年   6篇
  2014年   6篇
  2013年   21篇
  2012年   9篇
  2011年   22篇
  2010年   11篇
  2009年   9篇
  2008年   11篇
  2007年   13篇
  2006年   8篇
  2005年   5篇
  2003年   1篇
  2002年   4篇
  1999年   4篇
排序方式: 共有158条查询结果,搜索用时 15 毫秒
71.
Conflict with humans is one of the major threats facing the world's remaining large carnivore populations, and understanding human attitudes is key to improving coexistence. We surveyed people living near Hwange National Park about their attitudes toward coexisting with lions. We used ordinal regression models with the results of the survey to investigate the importance of a range of tangible and intangible factors on attitudes. The variables investigated included the costs and benefits of wildlife presence, emotion, culture, religion, vulnerability, risk perception, notions of responsibility, and personal value orientations. This was for the purpose of effectively tailoring conservation efforts but also for ethical policy making. Intangible factors (e.g., fear and ecocentric values) were as important as, if not more important than, tangible factors (such as livestock losses) for understanding attitudes, based on the effect sizes of these variables. The degree to which participants’ fear of lions interfered with their daily activities was the most influential variable. The degree to which benefits accrue to households from the nearby protected area was also highly influential, as was number of livestock lost, number of dependents, ecocentric value orientation, and participation in conflict mitigation programs. Contrary to what is often assumed, metrics of livestock loss did not dominate attitudes to coexistence with lions. Furthermore, we found that socioeconomic variables may appear important when studied in isolation, but their effect may disappear when controlling for variables related to beliefs, perceptions, and past experiences. This raises questions about the widespread reliance on socioeconomic variables in the field of human–wildlife conflict and coexistence. To facilitate coexistence with large carnivores, we recommend measures that reduce fear (through education and through protective measures that reduce the need to be fearful), reduction of livestock losses, and ensuring local communities benefit from conservation. Ecocentric values also emerged as influential, highlighting the need to develop conservation initiatives tailored to local values.  相似文献   
72.
International retirement migration has become an increasing phenomenon in the Mediterranean region of Alicante, Spain. Through an interdisciplinary approach, relationships between the migration process, landscape change and environmental impacts are examined. Lifestyle-related perceptions and demands of UK retirees are studied as a major driving force of urbanisation. The extent and quality of the process is assessed by statistical and land use data analysis. Results reveal a distinctive spatial pattern of in-migration and the emergence of an archetypical landscape, consisting of a mosaic of remaining natural and urbanised landscape along the Mediterranean coast. The paper discusses the necessity of retirees' integration into sustainable planning and decision making.  相似文献   
73.
In this paper the cost of producing the enzyme laccase by the white-rot fungus Trametes pubescens under both submerged (SmF) and solid-state fermentation (SSF) conditions was studied. The fungus was cultured using more than 45 culture medium compositions. The cost of production was estimated by analyzing the cost of the culture medium, the cost of equipment and the operating costs. The cost of the culture medium represented, in all cases, the highest contribution to the total cost, while, the cost of equipment was significantly low, representing less than 2% of the total costs. The cultivation under SSF conditions presented a final cost 50-fold lower than the one obtained when culturing under SmF conditions at flask scale. In addition, the laccase production under SSF conditions in tray bioreactors reduced the final cost 4-fold compared to the one obtained under SSF conditions at flask scale, obtaining a final price of 0.04 cent €/U.  相似文献   
74.
Fenton treatment (Fe2+/H2O2) and different ozone-based Advanced Oxidation Processes (AOPs) (O3, O3/OH and O3/H2O2) were evaluated as pre-treatment of a mature landfill leachate, in order to improve the biodegradability of its recalcitrant organic matter for subsequent biological treatment. With a two-fold diluted leachate, at optimised experimental conditions (initial pH 3, H2O2 to Fe2+ molar ratio of 3, Fe2+ dosage of 4 mmol L−1, and reaction time of 40 min) Fenton treatment removed about 46% of chemical oxygen demand (COD) and increased the five-day biochemical oxygen demand (BOD5) to COD ratio (BOD5/COD) from 0.01 to 0.15. The highest removal efficiency and biodegradability was achieved by ozone at higher pH values, solely or combined with H2O2. These results confirm the enhanced production of hydroxyl radical under such conditions. After the application for 60 min of ozone at 5.6 g O3 h−1, initial pH 7, and 400 mg L−1 of hydrogen peroxide, COD removal efficiency was 72% and BOD5/COD increased from 0.01 to 0.24. An estimation of the operating costs of the AOPs processes investigated revealed that Fe2+/H2O2 was the most economical system (8.2 € m−3 g−1 of COD removed) to treat the landfill leachate. This economic study, however, should be treated with caution since it does not consider the initial investment, prices at plant scale, maintenance and labour costs.  相似文献   
75.
Multi-elemental profiles in bark of green ash trees collected in three representative areas of Buenos Aires, Argentina and Montevideo, Uruguay, were assessed as potential air pollution indicators. Ten elements: Al, Ba, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn, were measured using inductively coupled plasma optical emissions spectrometry from 70 samples collected in different environments: central, residential and rural (reference site), in order to compare spatial patterns of metal concentration. The samples used as a control were collected from a nature reserve situated far away from any significant influences, not even a nearby road. The reference site (RF) exhibited the lowest concentrations of Al, Cr, Fe, Ni, Pb, and Zn. However, Ba and Mn showed similar concentrations in all measured sites. Magnesium is the only element that had a greater concentration in RF than at the other sites. Copper did not show any clear pattern. The Centre of Montevideo (MVD) showed higher concentrations of Al, Ba, Cr, Fe, Pb and Zn than the Centre of Buenos Aires (BA). In the A sectors, Montevideo (SAMVD) showed higher concentrations of Al, Cu, Mg, Ni, and Zn and lower concentrations of Ba, Cr, Fe, Mn, and Pb than Buenos Aires (SABA). In the B sectors, Montevideo (SBMVD) showed higher concentrations of Al, Ba, Cu, Fe, Pb, and Zn and lower concentrations of Cr and Mg than Buenos Aires (SBBA), but similar concentrations of Mn and Ni. The use of bark for biomonitoring metals allowed us to detect concentration differences related to the urban fabric and the different kinds of vehicles and their fuels. In the cities, the differences in metal concentrations detected in bark were more striking between the sectors than between centers, despite CBA being much larger than CMVD in population, extension and vehicular traffic.  相似文献   
76.
Spatial and temporal trends of tributyltin (TBT) pollution on the northern continental shelf of Portugal (5-34 m depth) were assessed using Nassarius reticulatus as a bioindicator. Imposex levels were determined in 2006 and 2010, and integrated with age readings from statoliths for a better chronological analysis of the data. Females affected with imposex were detected in 84% of the sites surveyed in 2006, with levels higher than the Ecological Quality Objective (EcoQO) set by the OSPAR Commission for N. reticulatus (VDSI < 0.3) in approximately half of those sites. In 2010, imposex was only detected in 20% of the surveyed sites and, when detected, the VDSI were lower than the EcoQO, except for one location. The comparison between the current results and the levels previously reported for 2004 and 2005 in the same offshore area evidences a clear decline of imposex in 2010 that confirms the efficacy of Regulation (EC) No. 782/2003 and the IMO AFS-Convention (entered into force in 2003 and 2008, respectively). Moreover, the age of the whelks used in the monitoring is estimated in 3-5 years, indicating that actual TBT water contamination in 2010 may in fact be lower than that extrapolated from the imposex levels. We conclude that the legislation was indeed very effective in reducing TBT pollution in the NW Portuguese continental shelf, not only in terms of the magnitude but also in terms of fast field repercussion.  相似文献   
77.
Forest fires play a critical role in landscape transformation, vegetation succession, soil degradation and air quality. Improvements in fire risk estimation are vital to reduce the negative impacts of fire, either by lessen burn severity or intensity through fuel management, or by aiding the natural vegetation recovery using post-fire treatments. This paper presents the methods to generate the input variables and the risk integration developed within the Firemap project (funded under the Spanish Ministry of Science and Technology) to map wildland fire risk for several regions of Spain. After defining the conceptual scheme for fire risk assessment, the paper describes the methods used to generate the risk parameters, and presents proposals for their integration into synthetic risk indices. The generation of the input variables was based on an extensive use of geographic information system and remote sensing technologies, since the project was intended to provide a spatial and temporal assessment of risk conditions. All variables were mapped at 1 km2 spatial resolution, and were integrated into a web-mapping service system. This service was active in the summer of 2007 for semi-operational testing of end-users. The paper also presents the first validation results of the danger index, by comparing temporal trends of different danger components and fire occurrence in the different study regions.  相似文献   
78.
In Patagonia, Argentina, watching dolphins, especially dusky dolphins (Lagenorhynchus obscurus), is a new tourist activity. Feeding time decreases and time to return to feeding after feeding is abandoned and time it takes a group of dolphins to feed increase in the presence of boats. Such effects on feeding behavior may exert energetic costs on dolphins and thus reduce an individual's survival and reproductive capacity or maybe associated with shifts in distribution. We sought to predict which behavioral changes modify the activity pattern of dolphins the most. We modeled behavioral sequences of dusky dolphins with Markov chains. We calculated transition probabilities from one activity to another and arranged them in a stochastic matrix model. The proportion of time dolphins dedicated to a given activity (activity budget) and the time it took a dolphin to resume that activity after it had been abandoned (recurrence time) were calculated. We used a sensitivity analysis of Markov chains to calculate the sensitivity of the time budget and the activity-resumption time to changes in behavioral transition probabilities. Feeding-time budget was most sensitive to changes in the probability of dolphins switching from traveling to feeding behavior and of maintaining feeding behavior. Thus, an increase in these probabilities would be associated with the largest reduction in the time dedicated to feeding. A reduction in the probability of changing from traveling to feeding would also be associated with the largest increases in the time it takes dolphins to resume feeding. To approach dolphins when they are traveling would not affect behavior less because presence of the boat may keep dolphins from returning to feeding. Our results may help operators of dolphin-watching vessels minimize negative effects on dolphins.  相似文献   
79.
This editorial reviews the evolution of the concepts of safety and quality that have been used in the traditional workplace. The traditional programs of safety are explored showing strengths and weaknesses. The concept of quality management is also viewed. Safety management and quality management principles, stages, and measurement are highlighted. The concepts of quality and safety guarantee are assessed. Total Quality Management concepts are reviewed and applied to safety quality. Total safety management principles are discussed. Finally, an analysis of the relationship between quality and safety from data collected from a company in Spain is presented.  相似文献   
80.
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