全文获取类型
收费全文 | 159篇 |
免费 | 2篇 |
国内免费 | 8篇 |
专业分类
废物处理 | 10篇 |
环保管理 | 43篇 |
综合类 | 73篇 |
基础理论 | 9篇 |
污染及防治 | 17篇 |
评价与监测 | 9篇 |
社会与环境 | 4篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 13篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 10篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有169条查询结果,搜索用时 93 毫秒
21.
22.
CO2是《京都议定书》要求减排的6种温室气体之一,《京都议定书》还确立了有助于发展中国家获得资金和先进技术的清洁发展机制(CDM)。本文结合实际工程案例,介绍了合成氨副产CO2气的回收和利用方法,为我国氮肥行业申请CDM项目资助,回收利用CO2,减少CO2排放提供技术参考。 相似文献
23.
Indicators of ecosystem recovery 总被引:6,自引:0,他引:6
24.
Jon D. Unruh 《Natural resources forum》2008,32(2):103-115
Land tenure plays a primary role in sustainable development efforts. However armed conflict and its repercussions reconfigure the network of social relations upon which all land tenure systems depend. In post‐conflict settings new laws have the opportunity to address tenure issues in the context of what people are already doing ‘on the ground’, with a view to moving from the fluidity of post‐conflict situations to a more solidified and peaceful social and legal environment. However there exists a lack of tools to analyze postwar land tenure and the prospects for reconstituting tenure systems to support recovery and development. This paper uses the Sustainable Livelihoods framework to examine postwar land tenure issues in order to draw out latent opportunities within emergent informal smallholder tenure constructs which may have utility in the reconstitution of national tenure systems. 相似文献
25.
Classic island biogeographic theory predicts that equilibrium will be reached when immigration and extinction rates are equal.
These rates are modified by number of species in source area, number of intermediate islands, distance to recipient island,
and size of intermediate islands. This general model has been variously modified and proposed to be a stochastic process with
minimal competitive interaction or heavily deterministic. Predictive models of recovery (regardless of the end point chosen)
have been based on the appropriateness of the MacArthur-Wilson models.
Because disturbance frequency, severity, and intensity vary in their effect on community dynamics, we propose that disturbance
levels should first be defined before evaluating the applicability of island biogeographical theory. Thus, we suggest a classification
system of four disturbance levels based on recovery patterns by primary and secondary succession and faunal organization by
primary (invasion of vacant areas) and secondary (remnant of previous community remains) processes.
Level 1A disturbances completely destroy communities with no upstream or downstream sources of colonizers, while some component
of near surface interstitial or hyporheic flora and fauna survive level 1B disturbances. Recovery has been reported to take
from five years to longer than 25 years, when most invading colonists do not have an aerial form.
Level 2 disturbances destroy the communities but leave upstream and downstream colonization sources (level 2A) and, sometimes,
a hyporheic pool of colonizers (level 2B). Recovery studies have indicated primary succession and faunal structuring patterns
(2A) with recovery times of 90–400 days or secondary succession and faunal structuring patterns (2B) with recovery times of
40–250 days.
Level 3 disturbances result in reduction in species abundance and diversity along a stream reach; level 4 disturbances result
in reduction of abundance and diversity in discrete patches. Both disturbance types lead to secondary succession and secondary
faunal organization. Recovery rates can be quite rapid, varying from less than 10 days to 100 or more days.
We suggest that island biogeographical models seem appropriate to recovery by secondary processes after level 3 and 4 disturbances,
where competition may be an important organizing factor, while models of numerical abundance and resource tracking are probably
of better use where community development is by primary succession (levels 1 and 2).
Development of predictive recovery models requires research that addresses a number of fundamental questions. These include
the role of hydrologic patterns on colonization dynamics, the role of nonaerial colonizers in recovery from level 1 disturbances,
and assessment of the impact of changes in the order of invasion by colonizers of varying energetic efficiencies. Finally,
we must be able to assemble these data and determine whether information that guides community organization at one level of
disturbance can provide insights into colonization dynamics at other levels. 相似文献
26.
Overview of case studies on recovery of aquatic systems from disturbance 总被引:13,自引:2,他引:13
Gerald J. Niemi Philip DeVore Naomi Detenbeck Debra Taylor Ann Lima John Pastor J. David Yount Robert J. Naiman 《Environmental management》1990,14(5):571-587
An extensive review of the published literature identified more than 150 case studies in which some aspect of resilience in
freshwater systems was reported. Approximately 79% of systems studied were lotic and the remainder lentic. Most of the stressor
types were chemical with DDT (N=29) and rotenone (N=15) the most common. The most common nonchemical stressors were logging
activity (N=16), flooding (N=8), dredging (N=3), and drought (N=7).
The variety of endpoints to which recovery could be measured ranged from sparse data for phytoplankton (N=13), periphyton
(N=6), and macrophytes (N=8) to relatively more data for fish (N=412) and macroinvertebrates (N=698). Unfortunately the same
characteristics were rarely measured consistently among sites. For example, with respect to fish, more than 30 different species
were studied and recovery was measured in many ways, most commonly on the basis of: (1) first reappearance of the species,
(2) return time of predisturbance densities, and (3) return time of predisturbance average individual size. Based on these
criteria, all systems in these studies seem to be resilient to most disturbances with most recovery times being less than
three years. Exceptions included when (1) the disturbance resulted in physical alteration of the existing habitat, (2) residual
pollutants remained in the system, or (3) the system was isolated and recolonization was suppressed. 相似文献
27.
铝型材表面处理工艺中产生大量碱洗废液,如不能有效回收,会造成严重环境污染与资源浪费。本文针对含有“长寿碱蚀剂”的废液提出了生石灰处理工艺,此工艺简单,效果好,完全可以实现工业化生产。同时,该法原料价格低廉易得,实现闭路循环,可以达到良好的社会效益与经济效益。 相似文献
28.
Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(II), which is a valuable metal. In this study, the precipitation of Ni(II) from strongly acidic wastewater using sodium dimethyldithiocarbamate (DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions (DDTC:Ni(II) molar ratio = 4:1; temperature = 25 °C), the Ni(II) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(II) to form DDTCNi precipitates. Further recovery experiments revealed that high-purity NiO can be obtained by the calcination of DDTCNi precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO2, CS2, H2O, CO2, and SO2. These results provide a basis for an effective Ni(II) recovery method from strongly acidic wastewater. 相似文献
29.
冷凝法回收油气问题的探讨 总被引:12,自引:0,他引:12
彭国庆 《石油化工环境保护》1999,(2):30-33
着重探讨在石油化工厂中利用引进的DE4800型油气回收装置回收轻质油品装车系统油气的经济效益与社会效益 相似文献
30.
二氧化碳的回收和利用 总被引:4,自引:0,他引:4
李建英 《石油化工环境保护》2004,27(2):40-41,44
炼油厂的制氢尾气中含有大量二氧化碳,将其分离回收并加以利用具有一定的社会效益和经济效益。 相似文献