全文获取类型
收费全文 | 91篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 2篇 |
环保管理 | 21篇 |
综合类 | 9篇 |
基础理论 | 34篇 |
污染及防治 | 18篇 |
评价与监测 | 4篇 |
社会与环境 | 5篇 |
灾害及防治 | 4篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1995年 | 5篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1978年 | 3篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 156 毫秒
1.
Ossie Geifman-Holtzman Eliezer J. Holtzman Theresa J. Vadnais Vincent E. Phillips Eleanor L. Capeless Diana W. Bianchi MD 《黑龙江环境通报》1995,15(3):261-268
The objective of this study was to detect fetal HLA-DQα gene sequences in maternal blood. HLA-DQα genotypes of 70 pregnant women and their partners were determined for type A1. We specifically sought couples where the father, but not the mother, had genotype A1. In 12 women, maternal blood samples were flow-sorted. Candidate fetal cells were isolated and amplified by using PCR primers specific for a paternal HLA-DQα A1 allele. Fetal HLA-DQα A1 genotype was predicted from sorted cells; amniocytes or cheek swabs were used for confirmation. Six of twelve sorted samples had amplification products indicating the presence of the HLA-DQα A1 allele; 6/12 did not. Prediction of the fetal genotype was 100 per cent correct, as determined by subsequent amplification of amniocytes or cheek swabs. We conclude that paternally inherited uniquely fetal HLA-DQα gene sequences can be identified in maternal blood. This system permits the identification of fetal cells independent of fetal gender, and has the potential for non-invasive prenatal diagnosis of paternally inherited conditions. 相似文献
2.
Decreased Runoff Response to Precipitation,Little Missouri River Basin,Northern Great Plains,USA
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Eleanor R. Griffin Jonathan M. Friedman 《Journal of the American Water Resources Association》2017,53(3):576-592
High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976‐2012 compared to 1939‐1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (<5%) in annual or growing season precipitation, but average annual runoff at the basin outlet decreased by 22%, with 66% of the reduction in flow occurring during the growing season. Our results show a statistically significant (p < 0.10) 27% decrease in the annual runoff response to precipitation (runoff ratio). Surface‐water withdrawals for various uses appear to account for <12% of the reduction in average annual flow volume, and we found no published or reported evidence of substantial flow reduction caused by groundwater pumping in this basin. Results of our analysis suggest that increases in monthly average maximum and minimum temperatures, including >1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin. 相似文献
3.
Koala Conservation Policy Process: Appraisal and Recommendations 总被引:1,自引:0,他引:1
Tim W. Clark Nicole Mazur † Steven J. Cork ‡ Steve Dovers § and Ronnie Harding 《Conservation biology》2000,14(3):681-690
4.
5.
Kirk R. Vincent Jonathan M. Friedman Eleanor R. Griffin 《Environmental management》2009,44(2):218-227
Removal of nonnative riparian trees is accelerating to conserve water and improve habitat for native species. Widespread control
of dominant species, however, can lead to unintended erosion. Helicopter herbicide application in 2003 along a 12-km reach
of the Rio Puerco, New Mexico, eliminated the target invasive species saltcedar (Tamarix spp.), which dominated the floodplain, as well as the native species sandbar willow (Salix exigua Nuttall), which occurred as a fringe along the channel. Herbicide application initiated a natural experiment testing the
importance of riparian vegetation for bank stability along this data-rich river. A flood three years later eroded about 680,000 m3 of sediment, increasing mean channel width of the sprayed reach by 84%. Erosion upstream and downstream from the sprayed
reach during this flood was inconsequential. Sand eroded from channel banks was transported an average of 5 km downstream
and deposited on the floodplain and channel bed. Although vegetation was killed across the floodplain in the sprayed reach,
erosion was almost entirely confined to the channel banks. The absence of dense, flexible woody stems on the banks reduced
drag on the flow, leading to high shear stress at the toe of the banks, fluvial erosion, bank undercutting, and mass failure.
The potential for increased erosion must be included in consideration of phreatophyte control projects. 相似文献
6.
The challenges currently facing resource managers are large-scale and complex, and demand new approaches to balance development and conservation goals. One approach that shows considerable promise for addressing these challenges is adaptive management, which by now is broadly seen as a natural, intuitive, and potentially effective way to address decision-making in the face of uncertainties. Yet the concept of adaptive management continues to evolve, and its record of success remains limited. In this article, we present an operational framework for adaptive decision-making, and describe the challenges and opportunities in applying it to real-world problems. We discuss the key elements required for adaptive decision-making, and their integration into an iterative process that highlights and distinguishes technical and social learning. We illustrate the elements and processes of the framework with some successful on-the-ground examples of natural resource management. Finally, we address some of the difficulties in applying learning-based management, and finish with a discussion of future directions and strategic challenges. 相似文献
7.
8.
Stephen T. Deyrup Laura E. Eckman Eleanor E. Lucadamo Patrick H. McCarthy Jacqueline C. Knapp Scott R. Smedley 《Chemoecology》2014,24(4):145-157
Delphastus catalinae (Horn) is a predatory ladybird beetle (Coccinellidae) commonly used as a biocontrol agent against greenhouse infestation by whiteflies. It belongs to the basal subfamily Microweisinae, a group for which chemical defenses have not been previously investigated. The larval and pupal stages of D. catalinae possess minute secretory hairs that produce droplets containing compounds of both isoprenoid and polyketide origin. Bioassays with the predatory ant Crematogaster lineolata showed both the larval and pupal secretions to be deterrent. Moreover, isolated secretion components, from both classes of compounds, displayed antipredator activity against the ant. Experiments with D. catalinae larvae fed isotopically labeled glucose showed 13C-incorporation into both categories of compounds within the pupal secretion, demonstrating that these antipredator compounds, which differ from the typical nitrogenous defensive molecules of coccinellids, are biosynthesized endogenously. This suggests that the wide use of alkaloids by more derived coccinellids may have arisen after their divergence from the more basal Microweisinae. 相似文献
9.
J. B. Koogler R. S. Sholtes A. L. Danis C. I. Harding 《Journal of the Air & Waste Management Association (1995)》2013,63(4):211-214
In conjunction with a 15-month air quality survey of Jacksonville, Fia., a mathematical model has been developed to describe the dispersion of atmospheric pollutants. The source inventory used with the model was compiled, in part, from the data obtained from the sampling of all major sources within the area. The major sources were considered separately from the one-mile square area sources which accounted for the remainder of the emissions. Meteorological data was recorded continuously in the city including vertical temperature observations to 750 ft. The model was compiled in FORTRAN and can be used for both gaseous and particulate pollutants, by utilizing proper decay rates. The variant nature of meteorological parameters and emission rates are considered. The ground level concentrations of several pollutants which were determined for 24 hr periods at 11 sites and continuously at two other sites were used to check the model. A limited tracer study was carried out in conjunction with the project. 相似文献
10.
S. F. Galeano C.I. Harding 《Journal of the Air & Waste Management Association (1995)》2013,63(8):536-539
The use of soda ash liquor to scrub SO2 rich power plant flue gases was studied using an Airetron pilot scrubber with a maximum capacity of 3000 cfm. The relative effects of the major operating variables— temperature, soda ash concentration, and the gas/liquid flow ratio—on the absorption phenomenon were determined. Orthogonal factorial experiments were used to derive a response function relating mass transfer values to operating variables. The economics of a full scale NSSC installation are discussed. 相似文献