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   61篇
  免费   0篇
安全科学   1篇
废物处理   2篇
环保管理   3篇
综合类   6篇
基础理论   9篇
环境理论   3篇
污染及防治   19篇
评价与监测   3篇
社会与环境   12篇
灾害及防治   3篇
  2023年   2篇
  2021年   1篇
  2019年   2篇
  2018年   3篇
  2016年   3篇
  2014年   5篇
  2013年   4篇
  2012年   2篇
  2011年   6篇
  2010年   2篇
  2009年   2篇
  2008年   4篇
  2007年   1篇
  2006年   4篇
  2005年   2篇
  2003年   3篇
  2002年   2篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1976年   1篇
  1975年   1篇
  1971年   1篇
  1958年   1篇
排序方式: 共有61条查询结果,搜索用时 15 毫秒
31.
32.
We conducted a multicity time-series study using monitoring data to assess seasonal patterns of short-term ozone–mortality association among elderly aged 65 years and over in Japan. Daily exposure to ambient ozone was computed using hourly measurements of photochemical oxidants available at multiple monitoring stations in each city. Effects of ozone on daily all-cause non-accidental, cardiovascular, and respiratory mortality were estimated using distributed lag linear models, controlling for confounding by temporal, day of the week, temperature, and flu epidemics. City-level effect estimates were combined using inverse variance meta-analysis. In spring and autumn, a 10-ppbv increase of daily maximum 8-h average ozone concentration in the previous 3 days was associated with 0.69 % (95 % confidence interval (CI): 0.27–1.10), 1.07 % (0.34–1.82), and 1.77 % (0.78–2.77) increases in daily all-cause, cardiovascular, and respiratory mortality, respectively. Forward displacement of respiratory mortality was large during the cold season despite lower ozone concentration. Results were generally independent of fine particulate matter and nitrogen dioxide. Findings suggest significant mortality effects of short-term ozone exposure among the elderly during the moderate season. Those with underlying respiratory diseases were susceptible, even during winter.  相似文献   
33.
The body of Information presented in this paper is directed to those Individuals concerned with the removal of NOx in combustion flue gases. A catalytic process for the selective reduction of nitrogen oxides by ammonia has been investigated. Efforts were made toward the development of catalysts resistant to SOx poisoning. Nitrogen oxides were reduced over various metal oxide catalysts in the presence or absence of SOx(SO2 and SO3). Catalysts consisting of oxides of base metals (for example, Fe2O3) were easily poisoned by SO3, forming sulfates of the base metals. A series of catalysts which are not susceptible to the SOx poisoning has been developed. The catalysts possess a high activity and selectivity over a wide range of temperatures, 250—450°C. The catalysts were tested in a pilot plant which treated a flue gas containing 110-150 ppm NOx, 660-750 ppm SO2, and 40-90 ppm SO3. The pilot plant was operated at 350°C and at a space velocity of 10,000 h-1. The removal of nitrogen oxides was more than 90% for several months.

A mechanism of the NO-NH3 reaction has also been investigated. It is found that NO reacts with NH3 at a 1:1 mole ratio in the presence of oxygen and the reaction is completely inhibited by the absence of oxygen. The experimental data show that the NO-NH3 reaction in the presence of oxygen is represented byNO + NH3 + 1/4 O2 = N2 + 3/2 H2O.  相似文献   
34.
In the wake of the catastrophic earthquake and tsunami that devastated part of northeastern Japan in March 2011, proposals for reconstruction and rehabilitation are still subjects of debate. The claim by many climate scientists that large-scale extreme events can be expected in the future, with similar catastrophic effects in coastal areas, suggests the need for long-term planning that aims at building resilience, the ability for socio-ecological systems to withstand and recover quickly from natural disasters, and continue to develop. We hypothesize that ecosystems and socio-economic resilience will provide affected communities with flexible barriers against future disasters and greater protection in the long run than will hard/engineering solutions such as high seawalls aimed at ensuring only physical security. Building social/ecological resilience in the Tohoku region will increase general security and is anticipated also to contribute to an enhanced quality of life now and for generations to come. This paper argues that building resilience in the affected area requires a transformation to sustainable agriculture, forestry and fisheries and we describe how the links between satoyama and satoumi, traditional rural territorial and coastal landscapes in Japan, can contribute to this revitalization and to strengthening the relationship between local residents and the landscape in the affected communities. Decision makers at local, regional and national levels need to take a holistic approach based on sustainability science to understand the inter-relationships between these landscapes and ecosystems to develop a robust rebuilding plan for the affected communities. Moreover, this paper suggests that building resilient communities in Japan that demonstrate the strategic benefits of satoyama and satoumi linkages can be a model for building resilient rural and urban communities throughout the world.  相似文献   
35.
The paper addresses disaster risk of an urban community in a mega city, which experiences high risk to natural hazards. The Community Action Planning (CAP) tool is used in this case. It has been developed from five resilience dimensions (physical, social, economic, institutional, and natural), 25 parameters and 75 actions. A detailed CAP structured questionnaire survey was conducted with 89 Residential and Welfare Associations (RWAs) in East Delhi, India situated in three types of settlements: planned Delhi Development Authority (DDA) housing and societies, colonies, and urban villages. The result identifies and prioritizes 32 actions as important for all three settlements. The result shows both consistent and inconsistent responses from RWAs. To give some examples, parameter S3 is “tasks to reduce number of people suffer from water borne diseases after a disaster”. In response to this parameter, approximately 80% of total respondents prioritized action (A1), “promoting people to take preventive measures after a disaster”. It shows consistent response from all three settlements. However, parameter S5 is “tasks to improve the awareness and knowledge about threat and impact of disasters”. Approximately 40% of total respondents prioritized A1, “organizing training program for awareness and knowledge building”. This action was prioritized in planned DDA housing and societies (56%) as well as in colonies (52%). However, none of the respondents from urban villages prioritized this action. These responses show inconsistency in response to specific action. In addition, the study shows the potential impact of CAP process for other communities in cities that are experiencing disaster risks and impact of climate change.  相似文献   
36.
37.
38.
An accurate estimation of a plant's age is required for the prediction of yield and management practices. This study demonstrates the relationship between backscattering properties (σ°) of Phased Array type L-band Synthetic Aperture Radar (PALSAR) dual polarimetric data with cashew plants' biophysical parameters (height, age, crown diameter, diameter at breast height, basal area, tree density, and biomass) in Cambodia. PALSAR σ° has shown a positive correlation with the biophysical parameters of cashew plants. The value of σ° increases with the age of cashew plants. At a young stage, the cashew plants show a higher rate of an increase in σ° compared to that at the mature stage. The σ° horizontal polarization transmitted and vertical received (HV) shows higher sensitivity to the plant's growth than σ° horizontal polarization transmitted and received (HH). High backscattering and low variations were observed at mature stage (8–12 years) of cashew plantation. Saturation in backscattering has shown from the age of about 13 years. The validation results indicate strong coefficient of determination (R 2?=?0.86 and 0.88) for PALSAR-predicted age and biomass of cashew plants with root mean square error?=?1.8 years and 16.3 t/ha for age and biomass, respectively. The correlations of σ° (HH) with biophysical parameters observed in the dry season were better than those of the rainy season because soil moisture interferes with backscattering in the rainy season. Biomass accumulation rate of cashew plants has been predicted that would be useful for selection of plants species to enhance carbon sequestration. This study provides an insight to use PALSAR for the monitoring of growth stages of plants at the regional level.  相似文献   
39.
Octachlorodibenzo-p-dioxin (OCDD)-added, pretreated fly ash was heated under vacuum at sample temperatures ranging from T(s)=450 to 650 K. The fly ash and liquid nitrogen-cooled trap samples were analyzed for DD/DF through OCDD/DF. The total amounts of DD through OCDD decrease with increasing T(s), which indicates that dechlorination/hydrogenation (DCH) reactions are not the only reaction channels. Reduction of toxic equivalent (TEQ) for PCDDs by more than 99% was achieved in the fly ash by the vacuum heat treatment at T(s)=650 K for 4 h. The total amount of PCDDs and DD detected in the liquid nitrogen-cooled trap relative to that of added OCDD was about 17%, i.e., PCDDs and DD which were adsorbed to the fly ash surfaces can evaporate into the gaseous phase. The difference between the evaporation behavior of PCDDs in the present and the previous studies is discussed in the light of their states of existence.  相似文献   
40.
To assess the capacity of the natural environment for degrading PHB/V, the film-MPN method proposed previously was modified to estimate the numbers of PHB/V degrading microorganisms (degraders) in various environments. The First-Order Reaction (FOR) model was used to determine the appropriate incubation period for the method. Numbers of aerobic PHB/V degraders were estimated in garden soil, paddy field soil, farm soil, river bank soil, infertile garden soil, river water, activated sludge, and seawater by the film-MPN method. Results were compared with those estimated by the clear-zone technique and showed that the film-MPN method was suitable for estimating the numbers of PHB/V degraders in the environments tested. On the other hand, biodegradability of injection molded PHB/V samples was investigated in several kinds of environments. The changes of weight were studied and results showed that biodegradability of PHB/V related to the numbers of PHB/V degraders in similar ecosystem in different regions. In different environments the biodegradability of PHB/V not only related to the number of PHB/V degraders, but also depended on whether there were conditions for the PHB/V degraders to grow and proliferate easily in the environment.  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