全文获取类型
收费全文 | 772篇 |
免费 | 9篇 |
国内免费 | 13篇 |
专业分类
安全科学 | 37篇 |
废物处理 | 41篇 |
环保管理 | 214篇 |
综合类 | 79篇 |
基础理论 | 161篇 |
污染及防治 | 182篇 |
评价与监测 | 51篇 |
社会与环境 | 28篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 10篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 16篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 20篇 |
2013年 | 94篇 |
2012年 | 19篇 |
2011年 | 45篇 |
2010年 | 24篇 |
2009年 | 35篇 |
2008年 | 45篇 |
2007年 | 43篇 |
2006年 | 47篇 |
2005年 | 17篇 |
2004年 | 20篇 |
2003年 | 36篇 |
2002年 | 28篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 15篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1974年 | 7篇 |
1973年 | 3篇 |
1970年 | 3篇 |
排序方式: 共有794条查询结果,搜索用时 945 毫秒
421.
Attanasio R Scinicariello F Blount BC Valentin-Blasini L Rogers KA Nguyen DC Murray HE 《Chemosphere》2011,84(10):1484-1488
Perchlorate is a known endocrine disruptor present in groundwater, vegetables and dairy food products in many regions of the United States. It interferes with the uptake of iodide into the thyrocyte by the sodium-iodide symporter at the basolateral surface, thus potentially disrupting the synthesis of thyroid hormone. Because transport of iodide from the thyroid follicular cells to the follicular lumen is mediated by the protein pendrin at the apical surface, we hypothesized that perchlorate may also interact with this protein. Therefore, HeLa cells were transfected with the human SLC26A4 gene, which encodes pendrin, to generate an in vitro mammalian system expressing the recombinant pendrin protein (HeLa-PDS). The HeLa-PDS cells, along with untransfected cells, were then cultured in presence of iodide and/or perchlorate. Intracellular levels of these two chemicals were measured by ion chromatography tandem mass spectrometry. Results from this study show that iodide and perchlorate uptake increases significantly in HeLa-PDS cells as compared to untransfected cells. Thus, recombinant HeLa cells expressing pendrin protein accumulate iodide and perchlorate intracellularly, indicating that pendrin is involved in the uptake of perchlorate. Additional results from this study suggest that iodide and perchlorate competitively inhibit each other for uptake by pendrin. The ability of perchlorate to compete with iodide for uptake by both basal and apical transporters may increase the potential of perturbation of thyroid homeostasis and therefore the estimated risk posed to susceptible human populations. 相似文献
422.
Arsenic-contaminated soils may pose a risk to human health. Redevelopment of contaminated sites may involve amending soils with organic matter, which potentially increases arsenic bioaccessibility. The effects of ageing on arsenic-contaminated soils mixed with peat moss were evaluated in a simulated ageing period representing two years, during which arsenic bioaccessibility was periodically measured. Significant increases (p = 0.032) in bioaccessibility were observed for 15 of 31 samples tested, particularly in comparison with samples originally containing >30% bioaccessible arsenic in soils naturally rich in organic matter (>25%). Samples where percent arsenic bioaccessibility was unchanged with age were generally poor in organic matter (average 7.7%) and contained both arsenopyrite and pentavalent arsenic forms that remained unaffected by the organic matter amendments. Results suggest that the addition of organic matter may lead to increases in arsenic bioaccessibility, which warrants caution in the evaluation of risks associated with redevelopment of arsenic-contaminated land. 相似文献
423.
Bettinetti R Quadroni S Crosa G Harper D Dickie J Kyalo M Mavuti K Galassi S 《Ambio》2011,40(4):341-350
Dichlorodiphenyltrichloroethane (DDT) is still used in Africa for the indoor control of malaria and it may represent a potential
hazard for wildlife. The littoral sediments of two alkaline-saline lakes, Natron (Tanzania) and Bogoria (Kenya), in the Eastern
Rift Valley, supporting large populations of lesser flamingos (Phoeniconaias minor), were analysed for DDT residues. Physical–chemical analyses (temperature, conductivity, pH and dissolved oxygen) were also
performed on the water of the two lakes and in the tributaries of Lake Natron, to evaluate the influence of the environmental
variables on pollutant occurrence. At Lake Natron, around 1 km from the sediment collection sites, tree leaves of Acacia tortilis were also collected. The main metabolite found in all sediment samples was pp’DDE, whilst equal concentrations of pp’DDT
and pp’DDE were measured in acacia leaves. The levels of DDTs measured in the sediments were within 5.9–30.9 ng g−1 d.w., reaching the maximum value in a tributary of Lake Natron. On the whole, the contamination of Lake Natron and Lake Bogoria
basins seems to be quite moderate. Nevertheless, the pp’DDE/pp’DDT ratio equals 1 in the Acacia tortilis leaves, which makes one suppose that the input of the parent compound was rather recent and could have been from aerial transport
or dust from relatively close-by old pesticides storage sites. 相似文献
424.
Dissolution kinetics of arsenic from soils and tailings were studied under simulated gastrointestinal conditions to determine the effects of residence time, pH and soil composition on the bioaccessibility of arsenic. The samples were sieved to four particle size fractions from bulk to <45 μm, and included arsenic minerals, soils and tailings with total arsenic concentrations ranging from 19 to 420 00 mg kg−1. The bioaccessible arsenic concentrations varied from 2.8 to 10 000 mg kg−1, and the highest concentrations were associated with the smallest particle size fractions. Kinetic parameters were determined for each sample extracted under gastric conditions (pH = 1.8) followed by intestinal conditions (pH = 7.0). Under gastric pH conditions, dissolution appeared to be diffusion-controlled and followed an exponential curve, whereas a logarithmic or linear model was used to describe the mixed dissolution mechanisms observed under intestinal conditions. Nine of the 13 samples tested reached a steady state bioaccessible arsenic concentration within the 5-h physiologically-based extraction test (PBET). However the bioaccessible arsenic concentrations in four tailings samples increased significantly (p = 0.034) between the 5-h and the extended 24-h extraction under intestinal conditions. Since arsenic absorption may occur along the entire digestive tract, assessments based on the standard 5-h PBET extraction may not adequately estimate the risks associated with arsenic absorption in such cases. The slow dissolution kinetics associated with secondary arsenic minerals in some tailings samples may require extending the PBET extractions to longer periods, or extrapolating using the proposed kinetic models, to reach steady state concentrations in simulated gastrointestinal fluids. 相似文献
425.
Prakash Doraiswamy Christian Hogrefe Winston Hao Robert F. Henry Kevin Civerolo Jia-Yeong Ku Gopal Sistla James J. Schwab Kenneth L. Demerjian 《Atmospheric environment (Oxford, England : 1994)》2009,43(36):5759-5770
This study compares speciated model-predicted concentrations (i.e., mixing ratios) of volatile organic compounds (VOCs) with measurements from the Photochemical Assessment Monitoring Stations (PAMS) network at sites within the northeastern US during June–August of 2006. Measurements of total non-methane organic compounds (NMOC), ozone (O3), oxides of nitrogen (NOx) and reactive nitrogen species (NOy) are used for supporting analysis. The measured VOC species were grouped into the surrogate classes used by the Carbon Bond IV (CB4) chemical mechanism. It was found that the model typically over-predicted all the CB4 VOC species, except isoprene, which might be linked to overestimated emissions. Even with over-predictions in the CB4 VOC species, model performance for daily maximum O3 was typically within ±15%. Analysis at an urban site in NY, where both NMOC and NOx data were available, suggested that the reasonable ozone performance may be possibly due to compensating overestimated NOx concentrations, thus modulating the NMOC/NOx ratio to be in similar ranges as that of observations. 相似文献
426.
Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant
physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands
on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams
to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We
used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and
disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams
could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of
headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence
of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the
replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance
during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should,
therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality. 相似文献
427.
428.
A comparison of web-based and telephone surveys for assessing traffic safety concerns, beliefs, and behaviors 总被引:1,自引:0,他引:1
Kenneth H. Beck Author Vitae Alice F. Yan Min Qi Wang 《Journal of Safety Research》2009,40(5):377-381
Introduction
The purpose of this investigation was to compare the results of a web-based and a telephone interview survey measuring driver concerns about a variety of traffic safety issues, their beliefs, and specific driving behaviors.Method
State-wide, annual random digit-dial telephone surveys and web-based surveys were conducted in Maryland. A total of 1,700 drivers were surveyed by telephone and 6,806 took a web survey.Results
Telephone respondents were more likely to be female and older. Web respondents were more likely to be white and not Latino/Hispanic. After controlling for demographic differences, telephone survey respondents were more likely to be concerned about traffic safety. They were more likely to believe that sobriety checkpoints reduce drunk driving (OR = 2.18, 95% CI 1.94, 2.45), they would be ticketed for not wearing a seat belt (OR = 1.26, 95% CI 1.12, 1.43), and they would be stopped by the police if they drove after drinking too much (OR = 1.17, 95% CI 1.03, 1.32). They were less likely to report a variety of risky behaviors including using a cell phone while driving (OR = .54, 95% CI .48, .61) and driving 10+ mph over the speed limit (OR = .81, 95% CI .72, .91), but were more likely to report having been ticketed for a moving violation in the last month (OR = 2.22, 95% CI 1.70, 2.90). Suggestions are offered for overcoming potential sources of sampling bias.Impact on Industry
Web-based surveys produce substantially different results than random-digit-dial telephone surveys, when used for public assessments of traffic safety concerns and behaviors. 相似文献429.
Daniel Q. Tong Rohit Mathur Daiwen Kang Shaocai Yu Kenneth L. Schere George Pouliot 《Atmospheric environment (Oxford, England : 1994)》2009,43(3):724-733
The main use of air quality forecast (AQF) models is to predict ozone (O3) exceedances of the primary O3 standard for informing the public of potential health concerns. This study presents the first evaluation of the performance of the Eta-CMAQ air quality forecast model to predict a variety of widely used seasonal mean and cumulative O3 exposure indices associated with vegetation using the U.S. AIRNow O3 observations. These exposure indices include two concentration-based O3 indices, M7 and M12 (the seasonal means of daytime 7-h and 12-h O3 concentrations, respectively), and three cumulative exposure-based indices, SUM06 (the sum of all hourly O3 concentrations ≥ 0.06 ppm), W126 (hourly concentrations weighed by a sigmoidal weighting function), and AOT40 (O3 concentrations accumulated over a threshold of 40 ppb during daylight hours). During a three-month simulation (July–September 2005), the model over predicted the M7 and M12 values by 8–9 ppb, or a NMB value of 19% and a NME value of 21%. The model predicts a central belt of high O3 extending from Southern California to Middle Atlantic where the seasonal means, M7 and M12 (the seasonal means of daytime 7-h and 12-h O3 concentrations), are higher than 50 ppbv. In contrast, the model is less capable of reproducing the observed cumulative indices. For AOT40, SUM06 and W126, the NMB and NME values are two- to three-fold of that for M7, M12 or peak 8-h O3 concentrations. The AOT40 values range from 2 to 33 ppm h by the model and from 1 to 40 ppm h by the monitors. There is a significantly higher AOT40 value experienced in the United States in comparison to Europe. The domain-wide mean SUM06 value is 14.4 ppm h, which is about 30% higher than W126, and 40% higher than AOT40 calculated from the same 3-month hourly O3 data. This suggests that SUM06 and W126 represent a more stringent standard than AOT40 if either the SUM06 or the W126 was used as a secondary O3 standard. Although CMAQ considerably over predicts SUM06 and W126 values at the low end, the model under predicts the extreme high exposure values (>50 ppm h). Most of these extreme high values are found at inland California sites. Based on our analysis, further improvement of the model is needed to better capture cumulative exposure indices. 相似文献
430.
Kenneth J. Tobin Marvin E. Bennett 《Journal of the American Water Resources Association》2012,48(2):221-234
Tobin, Kenneth J. and Marvin E. Bennett, 2012. Validation of Satellite Precipitation Adjustment Methodology From Seven Basins in the Continental United States. Journal of the American Water Resources Association (JAWRA) 48(2): 221‐234. DOI: 10.1111/j.1752‐1688.2011.00604.x Abstract: The precipitation science community has expressed concern regarding the ability of satellite‐based precipitation products to accurately capture rainfall values over land. There has been some work that has focused on addressing the deficiencies of satellite precipitation products, particularly on the adjustment of bias. This article outlines a methodology that adjusts satellite products utilizing ground‐based precipitation data. The approach is not a simple bias adjustment, but is a three‐step process that transforms a satellite product based on a ground‐based precipitation product (NEXRAD‐derived Multisensor Precipitation Estimator [MPE] product or rain‐gauge data). The developed methodology was successfully applied to seven moderate‐to‐large sized watersheds from continental United States (CONUS) and northern Mexico over a spectrum of climatic regimes ranging from dry to humid settings. Methodology validation is based on comparison of observed and simulated streamflow generated with SWAT (Soil and Water Assessment Tool) model using unadjusted and adjusted precipitation products as input. Streamflow comparison is based on mass balance error and Nash‐Sutcliffe efficiency coefficient. Finally, the contribution of how adjustment to correct misses, false alarms, and bias impacts adjusted datasets and the potential impact that the adjustment methodology can have on hydrological applications such as water resource monitoring and flood prediction are explored. 相似文献