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51.
为科学评估PM_(2.5)对生物体的综合生物效应,利用费氏弧菌检测了PM_(2.5)水溶性提取液的光抑制效应,统计分析了227组PM_(2.5)主要组分与发光抑制率的相关关系.实验结果表明:PM_(2.5)水溶性提取液的发光抑制率值与OC、NO-3、EC和微量元素等组分浓度显著相关,相关系数从高到低的排序为:OC微量元素ECNO-3(p0.01).PM_(2.5)中,主要来自燃煤、交通燃油、生物质燃烧及冶金工业污染源排放的组分(苯并(a)芘、Cl-、OC、Cu、K+、Mn、Zn、EC、Pb、Se、F-等)浓度与发光抑制率显著相关.此外,二次来源的NO-3、NH+4等组分浓度与发光抑制率在冬季和春季显著相关.  相似文献   
52.
This study employed a weekly diary method among a sample of 74 Midwestern college student workers in order to examine the within‐person relationships between work–school conflict, sleep quality, and fatigue over five weeks. Further, recovery self‐efficacy was proposed as a cross‐level moderator of the relation between sleep quality and fatigue. Results from multilevel analyses demonstrated that weekly work–school conflict was negatively related to weekly sleep quality and positively related to end‐of‐week fatigue, with sleep quality partially mediating the relation between work–school conflict and fatigue. These findings enhance understanding of the process by which work–school conflict contributes to college student workers' strain on a weekly basis. Additionally, student workers with low recovery self‐efficacy demonstrated a negative relation between sleep quality and fatigue; however, this relation did not exist for student workers with high recovery self‐efficacy. This finding suggests recovery self‐efficacy as an important resource that may reduce the association between poor sleep quality (as a result of work–school conflict) and fatigue. The current findings provide important theoretical and practical implications for researchers, organizations, and college institutions as a whole. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
53.
基于PMA-定量PCR选择性检测技术的病原菌消毒特性研究   总被引:1,自引:1,他引:1  
仝铁铮  吴舒旭  李丹  何苗  杨天  施汉昌 《环境科学》2011,32(4):1120-1126
建立了一种核酸染料propidium monoazide(PMA)与定量PCR技术联合选择性检测活性病原菌的技术(PMA-qPCR),以大肠杆菌作为模式菌,研究了氯和一氯胺消毒对病原菌的灭活特性.结果表明,PMA染料能够分别去除99.94%和99.99%的来自非活性大肠杆菌和沙门氏菌的DNA,PMA-qPCR技术能够有效区分活性菌与非活性菌;PMA-qPCR技术得到的氯和一氯胺消毒对大肠杆菌的灭活曲线符合一级动力学方程,灭活速率常数分别为 2.24 L·(mg·min)-1和0.0175 L·(mg·min)-1,低于平板培养法得到的灭活速率常数;当大肠杆菌的去除率达到99%时,采用PMA-qPCR技术检测需要的ct值相比于平板培养法从0.6 mg·L-1·min上升到0.9 mg·L-1·min(氯消毒)和从20 mg·L-1·min上升到超过100 mg·L-1·min(一氯胺消毒);随着ct值的升高,常规qPCR的检测结果基本不变,因此常规qPCR不能够反映氯和一氯胺消毒对病原菌的灭活效果.作为一种新的表征消毒特性的检测技术,PMA-qPCR技术有助于更为准确地评价氯和一氯胺消毒对病原菌的灭活效果.  相似文献   
54.
This study used both correlative and experimental video playback methods to test the hypothesis that the secondary sexual traits of male wolf spiders act to increase the efficacy of visual courtship displays. Direct observations of courtship of several lycosid genera and a review of the literature revealed a significant association between ornamentation and visual courtship displays. This suggests that the ornamentation may be playing the role of amplifier for a visual display. To test this hypothesis, male courtship behaviors of four Schizocosa species were experimentally manipulated using video-imaging techniques. Females of species with non-visually displaying, non-ornamented males (Schizocosa duplex and S. uetzi) did not increase in frequency of receptivity when tufts were added to conspecific males. In a species with a visual display and foreleg pigmentation (S. stridulans), the addition of foreleg tufts increased female receptivity. In a tufted species (S. crassipes), females tended to decrease their receptivity when male ornamentation was completely removed. In visually displaying species, ornamentation acts to increase female receptivity, supporting its role as an amplifier of a visual display. Received: 29 December 1997 / Received in revised form: 23 October 1999 / Accepted: 13 December 1999  相似文献   
55.
Water insecurity, induced or intensified due to climate change, has emerged as a key policy challenge in poor and developing countries such as India. Drawing on social cognitive theory, this paper examines the role of perceived collective efficacy—people's shared beliefs about their group's capabilities to accomplish collective tasks—and trust in government as factors influencing Indians' engagement with government water conservation policies. Using a national survey of Indians (N = 4031), we found that individuals with high levels of perceived collective efficacy and trust in government are more likely to support government water conservation policies. Moreover, for individuals with low trust in government, higher collective efficacy is associated with greater policy support. Perceived collective efficacy is also associated with activist behaviours, while distrust is not. Increasing collective efficacy beliefs, for example through mass media channels and targeted campaigns, could help increase citizens' engagement with climate change adaptation policies.  相似文献   
56.
为有效提升煤矿企业安全管理效能,提高矿工安全绩效,基于资源保存理论、社会认知理论和自我决定理论,以团队层面的团队效能感和个体层面的安全动机为中介变量,探讨团队关系冲突(TRC)对矿工安全绩效的跨层次影响机制.对40个班组347名矿工进行问卷调查和实证研究,结果表明:TRC不仅能直接负向影响矿工安全绩效,还能通过团队效能...  相似文献   
57.
The United States Environmental Protection Agency/Environmental Response Team (US EPA/ERT), in collaboration with St. John's College, Dr. B. R. Ambedkar University, Agra, India, is conducting a study to determine Hg vapor emission rates resulting from broken compact fluorescent lamps (CFLs) in a residential setting. The overall objectives of the study are to determine Hg vapor emission data and provide homeowners with cleanup procedures and disposal options for broken CFLs. Most of the currently available CFLs in the US market are manufactured in China for US companies. Several different types of CFLs were purchased from local stores and their Hg content was determined. Based on previous studies, such as the 2011 study by Singhvi and colleagues, five popular spiral CFLs were selected for emission studies in an acrylic chamber. This study found that Hg vapor emissions from CFLs may be significantly greater than those from beads of liquid Hg with weights comparable to the Hg content of the CFLs. The average 24-hour Hg loss into the atmosphere from CFLs broken on a plastic surface ranged from 0.6% to 22% of the bulb content, while that for CFLs broken on carpet ranged from 2.6% to 28%. Projections for a 12 foot × 9.33 foot × 8 foot (25.4 m3) room based on the chamber measurements in this study indicate that CFL breakage in some household settings may produce 24-hour Hg concentrations above the 2000 Agency for Toxic Substances and Disease Registry (ATSDR) minimum risk level (MRL) of 0.2 μg/m3, for typical air exchange rates. This study also indicates that Hg emission may not be proportional to exposed surface area based on experiments using liquid Hg with different surface areas.  相似文献   
58.
制药污泥的脱水处理及毒性削减是当前业界的研究热点。以污泥脱水性能(污泥比阻和泥饼含固率)和污泥综合急性毒性为评价指标,对2种不同型号PAM处理污泥的投加量进行优化,讨论了污泥絮凝脱水和毒性削减的机理。研究结果表明,处理100 mL原污泥,当制药污水厂现场使用的德国天使PAM和拓普戴克TOP8321型PAM投加量分别为4mg/L和12 mg/L时,污泥脱水性能达到最佳,此时污泥比阻从0.730×1012cm/g分别降低至0.126×1012cm/g和0.034×1012cm/g,泥饼含固率从16.32%分别提高至46.89%和34.98%;在毒性削减方面,2种混凝剂都可将污泥上清液毒性由微毒降至无毒,但对污泥毒性的削减效果不明显。对2种PAM的处理成本进行估算发现,污水厂现场使用的PAM对处理该制药污泥效果更佳,且费用相对较低,但要大幅度削减制药污泥的毒性需串联相应毒性削减技术和混凝沉淀单元。  相似文献   
59.
在水形势现状分析的基础上,提出了绿色用水的新理念;应用系统学方法,从绿色用水系统的功效分析出发,构建了以绿色水供给、绿色水消费和绿色水管理为基础的绿色用水系统结构,并与传统用水系统进行比较分析;进而从绿色用水的目的性出发,针对目前用水现状,从提供绿色用水科学范式、深化水资源综合规划改革、制定绿色用水导则和评价标准4个方面,提出了绿色用水实施路径。  相似文献   
60.
喷洒消油剂作为溢油应急的一种方法,简单、快速且能在大多数的海况下使用,在溢油应急中发挥了不可替代的作用。但由于消油剂是一种化学物质,对环境具有二次污染危险,所以消油剂的使用广受质疑。英国将消油剂作为主要的溢油应对措施,经过30年不断改进已形成了完善的包括消油剂在内的溢油处理产品批准和使用许可制度。通过对英国消油剂制度总结和分析,梳理并提出对中国政府主管部门改进、完善消油剂管理制度的建议。  相似文献   
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