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   159篇
  免费   4篇
  国内免费   3篇
安全科学   4篇
废物处理   10篇
环保管理   32篇
综合类   29篇
基础理论   60篇
污染及防治   20篇
评价与监测   6篇
社会与环境   4篇
灾害及防治   1篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2018年   2篇
  2017年   3篇
  2016年   2篇
  2015年   2篇
  2014年   5篇
  2013年   17篇
  2012年   6篇
  2011年   4篇
  2010年   5篇
  2009年   4篇
  2008年   5篇
  2007年   2篇
  2006年   5篇
  2005年   4篇
  2004年   9篇
  2003年   4篇
  2002年   2篇
  2001年   2篇
  2000年   5篇
  1999年   10篇
  1998年   3篇
  1997年   3篇
  1996年   4篇
  1995年   3篇
  1994年   3篇
  1993年   8篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   6篇
  1987年   5篇
  1986年   2篇
  1985年   2篇
  1984年   7篇
  1983年   2篇
  1982年   1篇
  1978年   2篇
  1976年   2篇
  1975年   3篇
  1974年   2篇
  1969年   1篇
  1967年   1篇
排序方式: 共有166条查询结果,搜索用时 15 毫秒
161.
Urban floods from thunderstorms cause severe problems in Metro Manila due to road traffic. Using Light Detection and Ranging (LiDAR)-derived topography, flood simulations and anecdotal reports, the root of surface flood problems in Metro Manila is identified. Majority of flood-prone areas are along the intersection of creeks and streets located in topographic lows. When creeks overflow or when rapidly accumulated street flood does not drain fast enough to the nearest stream channel, the intersecting road also gets flooded. Possible solutions include the elevation of roads or construction of well-designed drainage structures leading to the creeks. Proposed solutions to the flood problem of Metro Manila may avoid paralyzing traffic problems due to short-lived rain events, which according to Japan International Cooperation Agency (JICA) cost the Philippine economy 2.4 billion pesos/day.  相似文献   
162.
Children in refugee camps, and particularly those with disabilities, face unique challenges in accessing education and are at high risk of being marginalised. Best practices suggest that main-streaming is the optimal strategy for serving students with disabilities. This study examines the extent to which mainstreaming in a refugee camp helps to promote children's prosocial behaviours, taking into account their emotional and behavioural problems. In Kakuma Refugee Camp, Kenya, researchers collected data from the parents of children currently enrolled in special needs education centres (n=65) and from those formerly enrolled at these facilities who transitioned to mainstream classrooms (n=81). Children in mainstream schools functioned better in terms of prosocial behaviours, but this relationship disappeared when factoring in children's emotional and behavioural difficulties. In the context of a refugee camp, mainstreaming alone is not likely to help children's psychosocial and educational functioning, which requires dedicated supports, appropriate facilities and infrastructure, and a dual focus on disability-specific and disability-inclusive initiatives.  相似文献   
163.
Abstract: Individual species may be useful as indicators of biodiversity if an association exists between the presence of a species and another component of biodiversity. We evaluated 40 species of birds and small mammals, including 11 species of conservation concern, as potential indicators of species richness and species composition in southern California coastal sage scrub habitats. This habitat, which is the target of large-scale conservation planning, has been greatly reduced by human development and supports many plants and animals of conservation concern. We asked whether there is an association between the presence of a potential indicator species and the species richness and composition of the bird or small-mammal community in which it is found. We used point counts and live-trapping to quantify the distribution of birds and small mammals, respectively, at 155 points in 16 sites located in three counties. Of the few species we found associated with species richness, some were associated with higher species richness and others with lower richness, and species of conservation concern were not more frequently associated with species richness than were common species. Ordination analysis revealed a geographic gradient in coastal sage scrub bird and small-mammal species composition across southern California, and 18 of the species we evaluated were associated with the composition of the bird and small-mammal community in which they were found. Our results suggest that efforts to conserve bird and small-mammal biodiversity in coastal sage scrub should not focus exclusively on rare species or on locations with the highest species richness, but instead should focus on a diverse suite of species that are representative of the range of variation in communities found in coastal sage scrub habitats.  相似文献   
164.
Reconnecting to the Biosphere   总被引:3,自引:0,他引:3  
Humanity has emerged as a major force in the operation of the biosphere, with a significant imprint on the Earth System, challenging social-ecological resilience. This new situation calls for a fundamental shift in perspectives, world views, and institutions. Human development and progress must be reconnected to the capacity of the biosphere and essential ecosystem services to be sustained. Governance challenges include a highly interconnected and faster world, cascading social-ecological interactions and planetary boundaries that create vulnerabilities but also opportunities for social-ecological change and transformation. Tipping points and thresholds highlight the importance of understanding and managing resilience. New modes of flexible governance are emerging. A central challenge is to reconnect these efforts to the changing preconditions for societal development as active stewards of the Earth System. We suggest that the Millennium Development Goals need to be reframed in such a planetary stewardship context combined with a call for a new social contract on global sustainability. The ongoing mind shift in human relations with Earth and its boundaries provides exciting opportunities for societal development in collaboration with the biosphere--a global sustainability agenda for humanity.  相似文献   
165.
Nutrient mitigation capacity in Mississippi Delta, USA drainage ditches   总被引:1,自引:0,他引:1  
Eutrophication and hypoxia within aquatic systems are a serious international concern. Various management practices have been proposed to help alleviate nutrient loads transported to the Gulf of Mexico and other high-profile aquatic systems. The current study examined the nutrient mitigation capacity of a vegetated (V) and non-vegetated (NV) agricultural drainage ditch of similar size and landform in the Mississippi Delta. While no statistically significant differences in ammonium, nitrate, or dissolved inorganic phosphorus mitigation between the two ditches existed, there were significant differences in total inorganic phosphorus percent load reductions (V: 36% ± 4; NV: 71% ± 4). However, both agricultural drainage ditches were able to mitigate nutrients, thus reducing the load reaching downstream aquatic receiving systems. Further studies examining ecosystem dynamics within drainage ditches such as sediment and plant nutrient partitioning, as well as microbial processes involved, are needed to provide a better understanding of natural nutrient variability, seasonality and flux.  相似文献   
166.
As part of a larger program to investigate indoor sources of air pollution, an indoor/outdoor sampling program was carried out for NO, NO2, and CO In four private houses which had gas stoves. The four houses chosen for study represented different surrounding land use, life styles, and house age and layout. The pollutant gases were measured essentially simultaneously at three indoor locations and one outdoor location. The results of the program showed that indoor levels of NO and NO2 are directly related to stove use in the homes tested. Furthermore, these stoves often produced more NO2 than NO. In some instances, the levels of NO2 and CO in the kitchen exceeded the air quality standards for these pollutants if such outdoor standards were to be applied to indoors and the data for the sampling periods were typical of an entire year. A diffusion experiment conducted in one of the houses showed that the half-life for NO2 was less than one-third that for either NO or CO. Oxidation of NO to NO2 (based upon comparing the half-life of NO to CO) does not appear to occur to a significant degree indoors.  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