全文获取类型
收费全文 | 294篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 9篇 |
环保管理 | 36篇 |
综合类 | 98篇 |
基础理论 | 47篇 |
环境理论 | 1篇 |
污染及防治 | 81篇 |
评价与监测 | 9篇 |
社会与环境 | 10篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 28篇 |
2012年 | 14篇 |
2011年 | 26篇 |
2010年 | 20篇 |
2009年 | 13篇 |
2008年 | 17篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 3篇 |
1999年 | 2篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1960年 | 2篇 |
1957年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 15 毫秒
151.
152.
Jacob J. Burke 《Natural resources forum》2000,24(2):123-136
The paper suggests that the expansion of irrigated agriculture in the 20th century has de-coupled the water user from the inherent risk of exploiting both surface and groundwater resources. The apparent reliability of storage and conveyance infrastructure and the, relative cheapness and flexibility of groundwater exploitation offered by mechanised drilling and pumping have sheltered the end user from natural hydrological risk. The imperative for in-field irrigation efficiency has been effectively removed since the physical and economic management of the resource is determined by command area authorities or, in the case of some groundwater pumping, by the performance of power utilities, who have no direct interest in integrated resource conservation. As a result, the resource base has been degraded, and in some cases irreparable damage has occurred. It is argued that the rigidity of the resource management in many irrigation systems is not attuned to the inherent variability of natural systems upon which they depend. Further, the paper argues that irrigation management systems can work toward sustainability by spreading risk equitably, and transparently, amongst the resource regulators, managers and users. This has to involve a much more flexible approach to natural resource management that is conditioned not only by natural parameters, but also by the socio-economic settings. A range of examples highlights the variability and scale issues involved. 相似文献
153.
Gideon Oron Joel DeMalach Jacob E. Bearman 《Journal of the American Water Resources Association》1986,22(3):439-446
ABSTRACT: A preliminary field experiment was conducted for trickle irrigation of winter wheat raised for grain production under arid conditions. Treated waste water was applied for trickle irrigation via a trickle system. Mean total amount of effluent applied was about 5700 m3/ha. In one of the experimental treatments, which was irrigated once a week, a grain yield of over 10,000 kg/ha was obtained, whereas in the other treatments the yields were about 8,500 kg/ha, which are above the mean yield obtained under sprinkler irrigation. 相似文献
154.
ABSTRACT: We tested the common assumption, made when expressing phosphorus export on an areal basis, that this export is a linear function of catchment area and found it wanting. The data show that in agricultural catchments, TP (total phosphorus) export varies as the 0.77 power of drainage basin area, resulting in a reduction in phosphorus delivery per unit area with increasing catchment size. Following further division of catchments according to agricultural practice, we found that this spatial scale effect is restricted to row crops and pastures. We present simple statistical models to allow a comparison of TP export from catchments of different size. Such models are not needed for nonrow crops, mixed agricultural and forested catchments, where TP export is a linear function of catchment size. 相似文献
155.
Jacob von Oelreich Annika Carlsson-Kanyama Åsa Svenfelt Per Wikman-Svahn 《Local Environment》2015,20(4):459-473
A warmer climate leads to rising sea levels. Despite uncertainties about how rapid and substantial future sea-level rise (SLR) will be, society needs to prepare and adapt. This study examines the state of planning for future SLR in Sweden by surveying 33 coastal municipalities in southern Sweden and interviewing local, regional and national authorities with relevant accountability. The results reveal that there are considerable gaps in current planning for SLR. Almost one-third of municipalities lack guiding planning documents for SLR, and more than two-thirds do not discuss SLR beyond 2100. We argue that the prevailing uncertainty and ambiguity in assessments of future SLR is problematic within a traditional “predict-then-act” paradigm, and that robust approaches, such as scenario planning, can reduce many of these problems. 相似文献
156.
Balakrishnan Akash Appunni Sowmya Chinthala Mahendra Jacob Meenu Mariam Vo Dai-Viet N. Reddy Soreddy Sainath Kunnel Emmanuel Sebastian 《Environmental Chemistry Letters》2023,21(3):1881-1905
Environmental Chemistry Letters - Water contamination is increasing worldwide, yet actual methods of water and wastewater treatment are limited, in particular by actual fossil-fuel derived... 相似文献
157.
Metal mixtures in pregnant women and umbilical cord blood at urban populations—Rio de Janeiro,Brazil
de Figueiredo Nataly Damasceno Araújo Monica Seefelder Luiz Ronir R de Magalhaes Câmara Volney do Couto Jacob Silvana dos Santos Lisia Maria Gobbo Vicentini Santos Alves Asmus Carmen Ildes Rodrigues Froes 《Environmental science and pollution research international》2020,27(32):40210-40218
Environmental Science and Pollution Research - This study aims to assess interrelationships between serum lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) concentrations in pregnant women in... 相似文献
158.
Land cover changes as impacted by spatio-temporal rainfall variability along the Ethiopian Rift Valley escarpment 总被引:1,自引:0,他引:1
Sofie Annys Biadgilgn Demissie Amanuel Zenebe Abraha Miro Jacob Jan Nyssen 《Regional Environmental Change》2017,17(2):451-463
Magnitudes of land cover changes nowadays can be assessed properly, but their driving forces are subject to many discussions. Next to the accepted role of human influence, the impact of natural climate variability is often neglected. In this paper, the impact of rainfall variability on land cover changes (LCC) is investigated for the western escarpment of the Raya Graben along the northern Ethiopian Rift Valley. First, LCC between 2000 and 2014 were analysed at specific time steps using Landsat imagery. Based on the obtained LCC maps, the link was set with rainfall variability, obtained by means of the satellite-derived rainfall estimates (RFEs) from NOAA-CPC. After a correction by the incorporation of local meteorological station data, these estimates prove to be good estimators for the actual amount of precipitation (ρ RFE1.0 = 0.85, p = 0.00, n = 126; ρ RFE2.0 = 0.76, p = 0.00, n = 934). By performing several linear regression analyses, a significant positive relationship between the precipitation parameter DIFF 5Y (i.e. the at-RFE pixel scale difference in five-year average annual precipitation for the two periods preceding the land cover maps) and the changes in the woody vegetation cover was found (standardised regression coefficient β = 0.23, p = 0.02, n = 108). Despite the dominance of direct human impact, further greening of the study area can be expected for the future concomitantly to a wetter climate, if all other factors remain constant. 相似文献
159.
Vimal Kumar KG Dinesh Kumar PK Smitha BR Habeeb Rahman H Josia J Muraleedharan KR Sanjeevan VN Achuthankutty CT 《Environmental monitoring and assessment》2008,140(1-3):231-247
Seasonal variation of the hydrography along the southeast Arabian Sea is described using data collected onboard FORV Sagar
Sampada in September–October 2003 (later phase of Southwest monsoon, SWM) and March–April 2004 (Spring inter monsoon, SIM).
During the later phase of the SWM, upwelling was in the withdrawal phase and the frontal structure was clearer in the northern
sections (13 and 15°N lat) indicating strong upwelling in the area. The driving force of upwelling is identified as the combination
of alongshore wind stress and remote forcing with a latitudinal variability. Although a more prominent upwelling was found
in the north, a maximum surface Chlorophyll-a was found in the south (10°N). During the SIM, the area was characterized by oligotrophic water with relatively high Sea
Surface Temperature (>29°C) and low salinity (33.8 to 35.4). During March, the surface hydrography was found to be controlled
mainly by the intrusion of low-saline waters from the south, while during September by the high saline water from the north.
The presence of various water masses [Arabian Sea High Salinity Water (ASHSW), Persian Gulf Water (PGW), Red Sea Water (RSW)]
and their seasonal variations in the region is discussed and their decreasing influence towards the south is noted during
both periods of observation. During the SWM, the dynamic topography showed the equator-ward flow of the West India Coastal
Current (WICC) at the surface and a pole-ward coastal under current at sub-thermocline depth. During the SIM, surface circulation
revealed the WICC flowing pole-ward north of 13°N, but equator-ward flow in the south, with a clockwise circulation around
the Lakshadweep High. 相似文献
160.
Knudsen JJ Holbech H Madsen SS Bjerregaard P 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3374-3380
In streams, chemicals such as 17β-estradiol (E2) are likely to occur in pulses. We investigated uptake and biomarker responses in juvenile brown trout (Salmo trutta) of 3- or 6-h pulses of concentrations up to 370 ng E2 L−1. Uptake by the fish was estimated from disappearance of E2 from tank water. A single 6-h pulse of 370 ng E2 L−1 increased the plasma vitellogenin concentration, liver Erα- and vitellogenin-mRNA. Exposure to 150-160 ng E2 L−1 for 6 h increased vitellogenin in one experiment but not in another. Two 6-h pulses had a larger effect one pulse. Brown trout in the size range 24-74 g took up E2 linearly with time and exposure concentration with a concentration ratio rate of 20.2 h−1. In conclusion, the threshold for induction of estrogenic effects in juvenile brown trout at short term pulse exposure appears to be in the range 150-200 ng E2 L−1. 相似文献