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511.
This study, based on data collected from a representative sample of adults in the United States, explores the social cognitive variables that motivated Americans to validate rumours on social media about Hurricanes Harvey and Irma, both of which struck in August/September 2017. The results indicate that risk perception and negative emotions are positively related to systematic processing of relevant risk information, and that systematic processing is significantly related to rumour validation through search engines such as Google. In contrast, trust in information about the hurricane is significantly related to validation through official sources, such as FEMA (Federal Emergency Management Agency), and major news outlets such as The New York Times. Trust in information is also significantly related to systematic processing of risk information. The findings of this study suggest that ordinary citizens may be motivated to validate rumours on social media, which is an increasingly important issue in contemporary societies. 相似文献
512.
上海崇明岛蔬菜地土壤重金属含量与生态风险预警评估 总被引:41,自引:3,他引:38
崇明3城镇蔬菜地土壤重金属的总体含量为Cu 29.2 mg·kg-1、Pb 26.5 mg·kg-1、Cr 79.4 mg·kg-1、Zn 91.2 mg·kg-1和Cd 0.222 mg·kg-1.除Cd在城桥镇和陈家镇超过国家土壤一级标准(GB 15618-1995)外,其余均低于国家土壤一级标准,并且满足国家对绿色食品产地土壤重金属含量的要求(NY/T391-2000).与上海土壤背景值相比,Cu、Pb、Cr、Zn和Cd分别高出上海土壤背景值 24.3%、24.4%、22.9%、18.8%和65.7%.崇明3城镇蔬菜地土壤重金属生态风险预警评估得出,23个采样点中有3个样点属于中警,10个样点属于轻警,8个样点属于预警,1个样点属于无警,综合评估IER=1.562,为轻警.3城镇生态风险排序为堡镇(IER=1.799)>城桥镇(IER=1.636)>陈家镇(IER=1.368),均属于轻警. 相似文献
513.
Tomonori Ishigaki Chu Van Chung Nguyen Nhu Sang Michihiko Ike Koji Otsuka Masato Yamada Yuzo Inoue 《Journal of Material Cycles and Waste Management》2008,10(2):165-172
A methodology for estimating the methane emissions from waste landfills in Hanoi, Vietnam, as part of a case study on Asian
cities, was derived based on a survey of documents and statistics related to waste management, interviews with persons in
charge, and field investigations at landfill sites. The waste management system in Hanoi was analyzed to evaluate the methane
emissions from waste landfill sites. The quantity of waste deposited into the landfill was evaluated from an investigation
of the waste stream. The composition of municipal waste was surveyed in several districts in the Hanoi city area, and the
quantities of degradable organic waste that had been deposited into landfill for the past 15 years were estimated. Field surveys
on methane emissions from landfills of different ages (0.5, 2, and 8 years) were conducted and their methane emissions were
estimated to be 120, 22.5, and 4.38 ml/min/m2, respectively. The first-order reaction rate of methane generation was obtained as 0.51/year. Methane emissions from waste
landfills were calculated by a first-order decay model using this emission factor and the amount of landfilled degradable
waste. The estimates of methane emissions using the model accorded well with the estimates of the field survey. These results
revealed that methane emissions from waste landfills estimated by regional-specific and precise information on the waste stream
are essential for accurately determining the behavior of methane emissions from waste landfills in the past, present, and
future. 相似文献
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517.
为探究青春期的PFOS暴露对成年后的SD大鼠的生殖毒性,对出生后第21天(PND21)的SD大鼠经口灌胃不同剂量的PFOS(5、10和20mg·kg~(-1)),连续染毒7d,在出生后第56天(PND56)时,对各染毒组SD大鼠的体质量、精子数量、血清中的睾酮浓度,以及睾丸间质细胞睾酮合成的相关基因mRNA水平进行了检测。结果显示,10mg·kg~(-1)剂量组大鼠体质量较对照组明显下降(P<0.01);精子数量在10mg·kg~(-1)和20mg·kg~(-1)剂量组明显降低(P<0.05);血清中睾酮浓度随着PFOS剂量的加大有明显下降的趋势,20mg·kg~(-1)剂量组显著低于对照组(P<0.05);类/胆固醇相关基因star和cyp11α1的mRNA表达水平明显下调。研究表明,青春期的PFOS暴露会导致睾酮合成途径中相关因子的功能缺失,破坏成熟睾丸间质细胞的功能,致使睾酮水平降低,并抑制精子生成,从而破坏生殖系统的功能。 相似文献
518.
Effects of cement on redistribution of trace metals and dissolution of organics in sewage sludge and its inorganic waste-amended products 总被引:1,自引:0,他引:1
The suitability of using cement-stabilized sludge products as artificial soils in earth works was evaluated. The sludge products investigated were cemented sludge, cement-treated clay-amended sludge (SS+MC), and cement-treated copper slag-amended sludge (SS+CS). The leachability of lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) were assessed using the sequential extraction technique, toxicity characteristic leaching procedure (TCLP), NEN 7341 availability test, and column leaching test. The results indicated that Zn leachability was reduced in all the cement-stabilized sludge products. In contrast, Cu was transferred from the organic fraction to the readily leachable phases in the cement-stabilized sludge products and therefore exhibited increased leachability. The increased Cu leachability could be attributed to dissolution of humic substances in the sludge as a result of elevated pH. Good correlation between dissolved organic carbon (DOC) and heavy metal leaching from the cement-stabilized sludge products was observed in the column leaching experiment. Even with a cement percentage as small as 12.5%, calcium silicate hydrate (C-S-H) was formed in the SS+MC and SS+CS products. Inclusion of the marine clay in the SS+MC products could reduce the leaching potentials of Zn, and this was the great advantage of the marine clay over the copper slag for sludge amendment. 相似文献
519.
520.
Wen‐Cheng Huang Tung‐Hsin Chang Fu‐Ti Yang 《Journal of the American Water Resources Association》2001,37(5):1279-1289
ABSTRACT: The objective of this paper is to examine a deficit in water for the Hsinchu area, the location of Taiwan's “Silicon Valley.” The methods suggested in this paper to diagnose water shortage problems are simple and practical. The results show that Hsinchu is in an area without sufficient water to meet demand for domestic and industrial uses. Until the completion of the Baoshan II Reservoir in 2006, the most feasible options for the Taiwan Water Supply Corporation to offset the water deficiency in Hsinchu City over the next five years are: (a) to obtain water gratuitously from the southern Yungheshan Reservoir; (b) to import additional water at an extra charge from other sources such as the northern Shihmen Reservoir and the agricultural sector; and (c) to conduct a comprehensive water conservation program at the Hsinchu Science‐based Industrial Park. 相似文献