全文获取类型
收费全文 | 201篇 |
免费 | 1篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 31篇 |
废物处理 | 6篇 |
环保管理 | 32篇 |
综合类 | 24篇 |
基础理论 | 50篇 |
污染及防治 | 36篇 |
评价与监测 | 15篇 |
社会与环境 | 8篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 15篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有207条查询结果,搜索用时 62 毫秒
101.
102.
Howard-Reed C Wallace LA Ott WR 《Journal of the Air & Waste Management Association (1995)》2002,52(2):147-159
More than 300 air change rate experiments were completed in two occupied residences: a two-story detached house in Redwood City, CA, and a three-story townhouse in Reston, VA. A continuous monitor was used to measure the decay of SF6 tracer gas over periods of 1-18 hr. Each experiment first included a measurement of the air change rate with all exterior doors and windows closed (State 0), then a measurement with the single change from State 0 conditions of opening one or more windows. The overall average State 0 air change rate was 0.37 air changes per hour (hr(-1)) (SD = 0.10 hr(-1); n = 112) for the California house and 0.41 hr(-1) (SD = 0.19 hr(-1); n = 203) for the Virginia house. Indoor/outdoor temperature differences appeared to be responsible for the variation at the Virginia house of 0.15-0.85 hr(-1) when windows were closed. Opening a single window increased the State 0 air change rate by an amount roughly proportional to the width of the opening, reaching increments as high as 0.80 hr(-1) in the California house and 1.3 hr(-1) in the Virginia house. Multiple window openings increased the air change rate by amounts ranging from 0.10 to 2.8 hr(-1) in the California house and from 0.49 to 1.7 hr(-1) in the Virginia house. Compared with temperature differences and wind effects, opening windows produced the greatest increase in the air change rates measured in both homes. Results of this study indicate the importance of occupant window-opening behavior on a home's air change rate and the consequent need to incorporate this factor when estimating human exposure to indoor air pollutants. 相似文献
103.
Cynthia V. Burek B.Sc. M.Sc. Ph.D. F.G.S. John M. Cubitt B.Sc. Ph.D. F.G.S. 《Environmental geochemistry and health》1979,1(3):90-100
In an area of marginal farming, trace element distribution associated with lead, fluorite and baryte mineralization is important to the farmer because of the high infertility rate of the livestock and contamination of plant produce leading to the subsequent failure of the farming economy. Therefore sampling of superficial sediments was undertaken over the mineralized Carboniferous Limestone of North Derbyshire above the medieval lead and the modern fluorite workings. Twenty-seven elements were analyzed using emission spectrophotometry and subsequently compared with the geochemistry of the underlying bedrock. Discrepancies which occur are attributed to the glacial and periglacial action during the Wolstonian and Devensian glacial episodes. 相似文献
104.
We studied the effects of spatial and temporal timber harvesting constraints on competing objectives of sustaining wildlife habitat supply and meeting timber harvest objectives in a boreal mixedwood forest. A hierarchical modeling approach was taken, where strategic and tactical level models were used to project blocking and scheduling of harvest blocks. Harvest block size and proximity, together with short- and long-term temporal constraints, were adjusted in a factorial manner to allow creation of response-surface models. A new measure of the habitat mosaic was defined to describe the emergent pattern of habitat across the landscape. These models, together with multiple linear regression, were used to provide insight on convergence or divergence between spatial objectives. For example, green-up delay (defined as time required before a harvest block adjacent to a previously logged block can be scheduled for harvest) had an adverse effect on the amount of annual harvest area that could be allocated and blocked spatially, and habitat supply responded in an opposite direction to that of wood supply, where caribou, moose wintering, and marten habitat supply increased when harvest blocks were further apart, maximum block size smaller, and both a green-up delay and mesoscale stratification were applied. Although there was no "solution space" free of conflicts, the analysis suggests that application of the mesoscale stratification, together with a diversity of harvest block sizes and a between-harvest block proximity of 250 m, will perform relatively well with respect to wood supply objectives, and at the same time create a less fragmented landscape that better reflects natural forest patterns. 相似文献
105.
Stohlgren TJ Chong GW Schell LD Rimar KA Otsuki Y Lee M Kalkhan MA Villa CA 《Environmental management》2002,29(4):566-577
Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of
22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north–central United States.
In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation
areas were more invaded than high-elevation areas, and riparian zones were more invaded than nearby upland sites. For the
100 1000-m2 plots (across all vegetation types), 50% of the variation in nonnative species richness was explained by longitude, latitude,
native plant species richness, soil total percentage nitrogen, and mean maximum July temperature (n = 100 plots; P < 0.001). At the vegetation-type scale (n = 25 sets of four 1000-m2 plots/type), 64% of the variation in nonnative species richness was explained by native plant species richness, elevation,
and October to June precipitation (P < 0.001). The foliar cover of nonnative species (log) was strongly positively correlated with the nonnative species richness at the
plot scale (r = 0.77, P < 0.001) and vegetation-type scale (r = 0.83, P < 0.001). We concluded that, at the vegetation-type and regional scales in the north–central United States, (1) vegetation types
rich in native species are often highly vulnerable to invasion by nonnative plant species; (2) where several nonnative species
become established, nonnative species cover can substantially increase; (3) the attributes that maintain high native plant
species richness (high light, water, nitrogen, and temperatures) also help maintain nonnative plant species richness; and
(4) more care must be taken to preserve native species diversity in highly vulnerable habitats. 相似文献
106.
107.
108.
109.
An Accelerated Remediation Technologies (ART) In‐Well Technology pilot test was performed to evaluate the removal of chlorinated volatile organic compounds (VOCs) from groundwater. The ART In‐Well Technology was installed in one well located in the source area where dense nonaqueous‐phase liquid has been identified and VOC concentrations exceed 140,000 μg/L. Monitoring wells at the site were positioned between 10 and 170 feet from the ART test well. Overall, VOC concentrations from samples collected from the groundwater monitoring wells and in the vapors extracted for discharge from the ART treatment well were analyzed over the testing period. Monitoring results showed that concentrations of perchloroethylene were reduced in the closest monitoring well to nondetectable concentrations within 90 days. The cumulative removal of chlorinated VOCs from the ART test well over the six‐month pilot test period exceeded 9,500 pounds based on air monitoring data. The ART technology proved effective and cost‐efficient in reducing contaminant concentrations and removing a large mass of contamination from the subsurface in a short period of time. The radius of influence of the ART technology at the site was estimated to range between 65 and 170 feet. © 2007 Wiley Periodicals, Inc. 相似文献
110.
A case study of urban heat islands in the Carolinas 总被引:3,自引:0,他引:3
Urbanization tends to aggravate the negative effects of climate. The objective of this research is to aid in the understanding of the spatial variation of urban heat islands within selected cities in North and South Carolina. This understanding will help guide efforts to cool cities in order to increase human comfort, conserve energy and resources, and reduce air pollution in both of these states. 相似文献