全文获取类型
收费全文 | 799篇 |
免费 | 22篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 44篇 |
废物处理 | 51篇 |
环保管理 | 158篇 |
综合类 | 116篇 |
基础理论 | 156篇 |
环境理论 | 1篇 |
污染及防治 | 194篇 |
评价与监测 | 43篇 |
社会与环境 | 44篇 |
灾害及防治 | 19篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 21篇 |
2017年 | 21篇 |
2016年 | 31篇 |
2015年 | 25篇 |
2014年 | 29篇 |
2013年 | 74篇 |
2012年 | 34篇 |
2011年 | 57篇 |
2010年 | 29篇 |
2009年 | 28篇 |
2008年 | 33篇 |
2007年 | 38篇 |
2006年 | 38篇 |
2005年 | 36篇 |
2004年 | 17篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 22篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 11篇 |
1996年 | 8篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 15篇 |
1992年 | 14篇 |
1991年 | 18篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有826条查询结果,搜索用时 0 毫秒
61.
Vaughan Shilton Paul Giess David Mitchell Craig Williams 《Water, Air, & Soil Pollution: Focus》2002,2(5-6):237-246
Settled dust has been collected inside the main foyers ofthree University buildings in Wolverhampton City Centre,U.K. Two of the three buildings are located in a streetcanyon used almost exclusively by heavy duty dieselvehicles. The dust was collected on adhesive carbonspectro-tabs to be in a form suitable for analysis byscanning electron microscope and energy dispersive X-rayanalysis. Using these analytical techniques, individualparticle analysis was undertaken for morphology andchemistry. Seasonal variations and variations due tolocation were observed in both the morphologicalmeasurements and chemical analysis. Many of the differencesappear attributable to the influence of road traffic, inparticular, the heavy duty diesel vehicles, travellingalong the street canyon. 相似文献
62.
63.
Resource scarcity,energy use and environmental impact: A case study of the New Bedford,Massachusetts, USA,fisheries 总被引:3,自引:0,他引:3
The commercial fishing fleet in New Bedford, Massachusetts, USA, harvests seafood on George’s Bank, home of one of the nation’s
most productive fisheries. We calculated the energy return on investment (EROI) and carbon intensity of protein harvest in
the New Bedford fisheries from 1968 to 1988. EROI is the ratio of the energy content of the edible fish protein harvested
to the quantity of fossil fuel energy used directly in the harvesting process. Carbon intensity is the quantity of carbon
dioxide (CO2) released (from the burning of fossil fuels) per calorie of edible fish protein harvested. The results show that the EROI
of protein harvest declined from 0.18 to 0.028 from 1968 to 1988, indicating that the energy used to harvest seafood increased
from about 6 to 36 kcal of fuel for each kilocalorie of protein harvested. The quantity of CO2 released per calorie of edible fish protein is a linear function of energy use and therefore increased in a similar manner.
During this period there was a large increase in fishing effort (caused by the increase in the real price of seafood products,
favorable tax treatment for new vessel construction, and low interest loans from the government), and a decline in several
important species of fish. The results suggest that fishing pressure could be managed effectively by the regulation of fuel
use by the fleet. Despite the increase in the price of many seafood products, fishermen absorbed many of the costs of increasing
scarcity in the form of longer working hours and fewer men per vessel. 相似文献
64.
65.
66.
Energy-return-on-investment (ERI) analysis is a variation of more traditional cost-benefit analyses, a variation that is particularly important in times of diminishing fuel resources. We present a simple set of procedures for ERI analysis and apply those procedures to central New York State, where there is a proposal for a new 870 MWe coal-fired generating station. We compared the energy and dollar costs of building that facility with the costs of an alternative comprehensive regional program of insulation. The analysis showed that regional insulation was more efficient in conserving energy than the plant was in providing it by at least a factor of 4 in economic terms and by a factor of more than 15 when viewed as energy returned on energy invested. 相似文献
67.
Marion Babcock Bruce Mitchell 《Journal of the American Water Resources Association》1980,16(3):532-537
ABSTRACT: This study is an examination of the relationship between flooding and property values for an urban community in southwestern Ontario which has a lengthy history of flooding. As well, peoples’perceptions of the effect of flooding on property values is discussed. Analysis of sales prices and assessment data demonstrated no statistically significant differences in values of property for residences located in high- and low-risk areas either before or after a major flood in 1974. With both the high- and low-risk areas, sales prices after the 1974 flood were significantly higher than sales prices before the flood. The perceived property values followed a similar pattern. We concluded that differences in flood risk and flood experience did not adversely affect actual or perceived long-term property values. 相似文献
68.
J. Kent Mitchell Benjamin A. Jones 《Journal of the American Water Resources Association》1976,12(6):1205-1222
ABSTRACT: Micro-relief surface depression storage is one of the components of the rainfall-runoff process. The quantification of surface depression storage values and a depth-storage model to describe the storage was the subject of this study. Point measurement data were collected on 258 surfaces of 5 soils and three artificial surfaces. Five methods of computing storage, 15 depth-storage models, two depth increments, and six grid spacings were investigated. The 1-inch grid computational method, 0.1-inch depth increment, and 1-inch grid spacings were recommended. The surface depression storage function is best described by the model S = aDb, which relates surface depression storage as a function of depth with two equation parameters. Equations for describing the surface depression storage model parameters have been developed. 相似文献
69.
Rutter AP Schauer JJ Lough GC Snyder DC Kolb CJ Von Klooster S Rudolf T Manolopoulos H Olson ML 《Journal of environmental monitoring : JEM》2008,10(1):102-108
Gaseous elemental mercury (GEM), particulate mercury (PHg) and reactive gaseous mercury (RGM) were measured every other hour at a rural location in south central Wisconsin (Devil's Lake State Park, WI, USA) between April 2003 and March 2004, and at a predominantly downwind urban site in southeastern Wisconsin (Milwaukee, WI, USA) between June 2004 and May 2005. Annual averages of GEM, PHg, and RGM at the urban site were statistically higher than those measured at the rural site. Pollution roses of GEM and reactive mercury (RM; sum of PHg and RGM) at the rural and urban sites revealed the influences of point source emissions in surrounding counties that were consistent with the US EPA 1999 National Emission Inventory and the 2003-2005 US EPA Toxics Release Inventory. Source-receptor relationships at both sites were studied by quantifying the impacts of point sources on mercury concentrations. Time series of GEM, PHg, and RGM concentrations were sorted into two categories; time periods dominated by impacts from point sources, and time periods dominated by mercury from non-point sources. The analysis revealed average point source contributions to GEM, PHg, and RGM concentration measurements to be significant over the year long studies. At the rural site, contributions to annual average concentrations were: GEM (2%; 0.04 ng m(-3)); and, RM (48%; 5.7 pg m(-3)). At the urban site, contributions to annual average concentrations were: GEM (33%; 0.81 ng m(-3)); and, RM (64%; 13.8 pg m(-3)). 相似文献
70.
How do distinct visual stimuli help bumblebees discover flowers before they have experienced any reward outside of their nest? Two visual floral properties, type of a pattern (concentric vs radial) and its position on unrewarding artificial flowers (central vs peripheral on corolla), were manipulated in two experiments. Both visual properties showed significant effects on floral choice. When pitted against each other, pattern was more important than position. Experiment 1 shows a significant effect of concentric pattern position, and experiment 2 shows a significant preference towards radial patterns regardless of their position. These results show that the presence of markings at the center of a flower are not so important as the presence of markings that will direct bees there. 相似文献