全文获取类型
收费全文 | 34篇 |
免费 | 1篇 |
国内免费 | 13篇 |
专业分类
环保管理 | 2篇 |
综合类 | 22篇 |
基础理论 | 8篇 |
污染及防治 | 11篇 |
评价与监测 | 5篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2003年 | 2篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有48条查询结果,搜索用时 31 毫秒
11.
在南极苔藓植被的微环境区内 ,CO2 的浓度在 4 73 5mg·m- 3以上 ,大大高于全球CO2 的平均浓度 (3 56mg·m- 3) ,可见苔藓等植被区可能是大气CO2 的源之一 .这与特殊的南极条件下植被的生理生态特性有关 .在苔藓分布区 ,CO2 浓度日变化的主要影响因素是光照和温度 .菲尔德斯半岛变化无常的天气状况使得CO2 浓度昼夜变化规律出现局部波动 ,不同的天气状况也使CO2 浓度发生变化 .研究表明 :光照条件是CO2 浓度变化的主导影响因素 ,从CO2 浓度的季节变化中可以看出 ,CO2 浓度变化与大气温度呈负相关 ;与降水量和空气相对湿度呈正相关 .本文首次给出了极地环境下植被微区的CO2 浓度变化及其影响因素 ,为极地温室气体的研究提供了新的材料 相似文献
12.
2016 marked the 25th anniversary of the Protocol on Environmental Protection to the Antarctic Treaty. Terrestrial ice-free areas constitute approximately 0.18% of Antarctica, but represent the most biologically active, historically rich, and environmentally sensitive sites. Antarctic soils are easily disturbed and environmental legacies of human activities are scattered across the continent; many are remnants of the 1950s-1980s when environmental protection was less comprehensive than today. Adoption of the Environmental Protocol in 1991 represented an important and proactive shift in Antarctic governance, securing environmental protection as a fundamental tenet of the Treaty System. Twenty five years on standards of environmental management have greatly improved, yet environmental pressures are compounding. Shortcomings in the implementation of the Environmental Protocol exist due to disparities in cultural values, operational realities, and inconsistent environmental impact assessments among governments and National Antarctic Programs. Non-native species management remains underdeveloped; and there is inadequate representation of all biogeographic regions within the Protected Area system; therefore jeopardizing conservation of Antarctic biodiversity and the integrity of the soil environment. Fundamental improvements are required to address the current shortcomings and ensure effective environmental protection for the next 25 years, including: (1) increased multinational and multidisciplinary collaboration to answer targeted research questions addressing contemporary management challenges, (2) effective communication of science to policy makers and environmental managers to inform decision- making, and (3) making the mandate of long-term monitoring of the terrestrial environment a high priority for all governments signatory to the Antarctic Treaty. 相似文献
13.
Alessandra Cincinelli Tania Martellini Luciano Lepri Nicoletta Borghesi Rebecca M. Dickhut 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2153-2158
Mean hexachlorobenzene (HCB) and hexachlorocyclohexane (HCH) concentrations, measured in seawater and air samples, confirmed the decline in levels of these compounds in Antarctic air and water. However, low α/γ-HCH ratios in air at the beginning of the sampling period suggest a predominance of fresh lindane entering the Antarctic atmosphere during the Austral spring probably due to current use in the Southern Hemisphere. Water-air fugacity ratios demonstrate the potential for HCH gas deposition to coastal Antarctic seas, while the water-air fugacity ratios for HCB imply that volatilization does not account for the observed decrease of HCB in surface seawater. HCH concentrations found in krill samples were correlated with seawater concentrations indicative of bioconcentration of HCHs from seawater. 相似文献
14.
Gautami Samui Runa Antony Kanthanathan Mahalinganathan Meloth Thamban 《环境科学学报(英文版)》2017,29(7):258-269
Spatial trends of acetate(Ac~-) and formate(Fo~-) were determined in surface snow samples along a coastal-inland transect(180 km) in the ice cap region at Princess Elizabeth Land and along a coastal transect in the Amery Ice Shelf(130 km),East Antarctica.Variations in both Ac-and Fo-seem to be unrelated to the acidity of snow.Ionic balance determined for the snow samples indicate the availability of HNO3 that could undergo photolysis to produce hydroxyl radical(UOH),one of the major reactants involved in oxidation reactions with organic matter.The strong positive correlations between Ac~- and NO~-_3 in snow from both regions indicate that NO~-_3 mediatedUOH-oxidation of organic compounds in snow could be an important source of Ac-within the snowpack.On the other hand,negative correlation between Fo~- and NO~-_3 might indicate that sources other thanUOH-oxidation of organic matter may be dominant in the case of Fo~-.Higher Ac~- concentrations in the ice cap compared to the ice shelf correspond with long-range transport of biomass burning emissions to the ice cap region.Interaction of Ac~- and Fo~- with alkaline minerals could lead to their stability in the snowpack and minimize their loss from the snow surface.Resident microbial communities could also influence the budget of the carboxylic acids in snow. 相似文献
15.
16.
Environmental Impact Assessment Under the National Environmental Policy Act and the Protocol on Environmental Protection to the Antarctic Treaty 总被引:3,自引:0,他引:3
US government actions undertaken in Antarctica are subject to the requirements of both the Protocol and the US National Environmental
Policy Act (NEPA). There are differences in the scope and intent of the Protocol and NEPA; however, both require environmental
impact assessment (EIA) as part of the planning process for proposed actions that have the potential for environmental impacts.
In this paper we describe the two instruments and highlight key similarities and differences with particular attention to
EIA. Through this comparison of the EIA requirements of NEPA and the Protocol, we show how the requirements of each can be
used in concert to provide enhanced environmental protection for the antarctic environment. NEPA applies only to actions of
the US government; therefore, because NEPA includes certain desirable attributes that have been refined and clarified through
numerous court cases, and because the Protocol is just entering implementation internationally, some recommendations are made
for strengthening the procedural requirements of the Protocol for activities undertaken by all Parties in Antarctica.
The Protocol gives clear and strong guidance for protection of specific, valued antarctic environmental resources including
intrinsic wilderness and aesthetic values, and the value of Antarctica as an area for scientific research. That guidance requires
a higher standard of environmental protection for Antarctica than is required in other parts of the world. This paper shows
that taken together NEPA and the Protocol call for closer examination of proposed actions and a more rigorous consideration
of environmental impacts than either would alone. Three areas are identified where the EIA provisions of the Protocol could
be strengthened to improve its effectiveness. First, the thresholds defined by the Protocol need to be clarified. Specifically,
the meanings of the terms “minor” and “transitory” are not clear in the context of the Protocol. The use of “or” in the phrase
“minor or transitory” further confuses the meaning. Second, cumulative impact assessment is called for by the Protocol but
is not defined. A clear definition could reduce the chance that cumulative impacts would be given inadequate consideration.
Finally, the public has limited opportunities to comment on or influence the preparation of initial or comprehensive environmental
evaluations. Experience has shown that public input to environmental documents has a considerable influence on agency decision
making and the quality of EIA that agencies perform. 相似文献
17.
18.
应用密闭箱法首次测定了南极法尔兹半岛苔藓、地衣植被土壤CH4 排放通量 ,并估算了该半岛植被土壤在夏季 2个月内CH4 的排放总量 .结果表明 :在晴好天气条件下 ,苔藓土壤CH4 排放通量可能呈现双峰型变化特征 ;而在雨、雪等复杂多变的天气条件下 ,CH4 通量变化无规则 ,存在较大的时空变化 ,且与温度的响应关系不明显 ;苔藓土壤CH4 通量夏季变化的主要影响因子是温度 ,同时还受降水的影响 .苔藓土壤吸收CH4 总量为 0 6 6 5 3× 10 2 kg ;地衣土壤吸收CH4 总量为 0 76 0 3×10 2 kg .由此可见 ,该半岛苔藓、地衣植被土壤起着大气CH4 汇的作用 相似文献
19.
Sincetheinternationalgeophysicalyear(IGY,1957—1958),Antarcticahasbeentheobjectofintensivescientificinvestigationbyteamsofscientists... 相似文献
20.
Monitoring atmospheric nitrous oxide background concentrations at Zhongshan Station, east Antarctica
Wenjuan Ye Lingen Bian Can Wang Renbin Zhu Xiangdong Zheng Minghu Ding 《环境科学学报(英文版)》2016,28(9):193-200
At present,continuous observation data for atmospheric nitrous oxide(N_2O) concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station(69°22′25″S,76°22′14″E),east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change. 相似文献