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591.
Problem: Some evidence exists that drivers choose to engage in secondary tasks when the driving demand is low (e.g., when the car is stopped). While such a behavior might generally be considered as rather safe, it could be argued that the associated diversion of attention away from the road still leads to a reduction of situational awareness, which might increase collision risk once the car regains motion. This is especially relevant for texting, which is associated with considerable eyes-off-the-road-time. Nonetheless, it seems that previous research has barely addressed the actual engagement in secondary tasks while waiting at a red light (as compared to just addressing the tasks’ mere prevalence). Objective: The present study investigated secondary task engagement while stopped at a red light using European naturalistic driving data collected through the UDRIVE project. Attention was given to the whole engagement process, including simple prevalence and the tasks’ relation (in terms of start/end) to the red light period. Moreover, given that texting is one of the most problematic forms of distraction, it was characterized in more detail regarding glance behavior. Method: Videos of 804 red light episodes from 159 drivers were annotated. Glance behavior was also coded for a sub-set of 75 texting events and their matched baselines. Results, conclusions and practical applications: Drivers engaged in at least one secondary task across almost half of the annotated red light episodes. Drivers who texted while stopped spent most of the time looking at their cell phone. Consequently, drivers might not have been prepared for potentially unexpected events once the light turned green. Further, drivers concluded texting a considerable number of times well after the red light period, which has potential implications for traffic safety.  相似文献   
592.
How science and policy interact has been a major research focus in the International Relations (IR) tradition, using the epistemic community (EC) concept, as well as in the alternative perspective of Science and Technology Studies (STS). Should science be autonomous and as apolitical as possible in order to ‘speak truth to power’, as suggested by EC or should the inevitable entanglement of science and politics be accepted and embraced so as to make advice more conducive to negotiating the explicit travails of political decision-making as suggested by STS? With this point of departure, we compare similarities and differences between science–policy interactions in the issue areas of eutrophication and fisheries management of the Baltic Sea. To examine how knowledge is mobilised, the concepts of ‘uncertainty’ and ‘coherence’ are developed, drawing on both EC and STS thinking. We then reflect on the explanatory value of these approaches in both cases and discuss how a separation of science and policy-making in the pursuit of achieving scientific consensus leads to ineffectual policies. Drawing on STS thinking, we urge for a re-conceptualisation of coherence in order to accommodate a more reflexive practice of science–policy interactions.  相似文献   
593.
采用原位氧化还原法制备了三维石墨烯负载型CeO_2催化剂(CeO_2/3D GN),采用XRD、FTIR、SEM、比表面积和零电荷点测定等方法对其进行了表征,并考察了CeO_2/3D GN非均相催化臭氧氧化降解水中刚果红染料的影响因素。表征结果显示:CeO_2/3D GN具有相互连通的三维网络结构;CeO_2纳米颗粒均匀地分散在石墨烯片层中;比表面积为190.89 m~2/g;零电荷点pH_(zpc)为7.36。实验结果表明:CeO_2/3D GN非均相催化臭氧氧化体系比单独臭氧氧化体系对刚果红溶液的脱色率提高了60.56百分点;连续5次重复利用CeO_2/3D GN,刚果红溶液脱色率为96.50%~98.00%;在臭氧流量为20 mg/min、催化剂投加量为1.5 g/L、初始溶液pH为7.00的最佳工艺条件下反应15 min,刚果红溶液脱色率可高达94.65%。  相似文献   
594.
以厦门海岸带湿地为研究目标,收集调查从20世纪50年代至今与厦门海岸带湿地相关的资料和数据,从浅海海域面积的减少,近岸泥沙淤积,底部沉积物改变,红树林的面积减少4个方面,分析厦门海岸带湿地长期变化的状况和原因,并在此基础上进一步从厦门海域水质变化、近海底栖生物类型变化、航道淤积、水产养殖问题和珍稀海洋动物生存状况5个方面分析由于海岸带湿地变化对厦门海湾生态环境产生的影响。  相似文献   
595.
东海浮游多毛类的时空分布   总被引:3,自引:0,他引:3  
根据1997~2000年东海23°30′~33°00′N、118°30′~128°00′E海域4个季节海洋调查资料,探讨了东海浮游多毛类数量变化、相应的动力学过程及与渔场的关系。结果表明:浮游多毛类秋季平均丰度为23.68×10-2/m3,夏季8.59×10-2/m3,冬季5.80×10-2/m3,春季最低(1.20×10-2/m3);温度在多毛类丰度的季节变化中起主要作用,盐度次之。除了秋季,其他季节多毛类丰度平面分布较为均匀。多毛类的数量波动,与东海暖流势力消长和沿岸水有密切的联系,也同暖流势力从夏季到秋季维持一段时间有密切关系。  相似文献   
596.
中国海域赤潮发生趋势的年际变化   总被引:2,自引:0,他引:2  
回顾了中国海域的赤潮发生频次等数据的年际变化,尤其是进入21世纪的赤潮发生趋势,以期为赤潮灾害分析和防治提供帮助。数据表明,赤潮问题已不容忽视。总体上,赤潮发生的频次和累计面积呈现增长趋势,尤其是21世纪前10年的赤潮发生频次和规模是20世纪后50年的2倍多。与20世纪不同,东海的赤潮问题最严重,远远超过了南海;而渤海的赤潮规模也明显增加,此2海区成为赤潮的重灾区。赤潮多发生在5、6月份,但有延长的态势,对赤潮监测和预防提出了新的要求。赤潮生物,特别是有毒藻类不断增加,对渔业和人类健康造成威胁。同时也看到,赤潮的发生并非持续上涨,赤潮是可以防治的。  相似文献   
597.
次溴酸盐氧化法测定海水中氨氮试验条件的优化   总被引:1,自引:0,他引:1  
对次溴酸盐氧化法测定海水中氨氮的试验条件进行优化,考察了温度、氧化时间、次溴酸盐用量、氨基酸等影响因素,以及干扰离子对测定的影响。方法在0 mg/L~0.100 mg/L范围内线性良好,检出限为0.8 μg/L,标准溶液平行测定的RSD为4.4%,能力验证样品的测定结果合格。  相似文献   
598.
Seasonal variation of the hydrography along the southeast Arabian Sea is described using data collected onboard FORV Sagar Sampada in September–October 2003 (later phase of Southwest monsoon, SWM) and March–April 2004 (Spring inter monsoon, SIM). During the later phase of the SWM, upwelling was in the withdrawal phase and the frontal structure was clearer in the northern sections (13 and 15°N lat) indicating strong upwelling in the area. The driving force of upwelling is identified as the combination of alongshore wind stress and remote forcing with a latitudinal variability. Although a more prominent upwelling was found in the north, a maximum surface Chlorophyll-a was found in the south (10°N). During the SIM, the area was characterized by oligotrophic water with relatively high Sea Surface Temperature (>29°C) and low salinity (33.8 to 35.4). During March, the surface hydrography was found to be controlled mainly by the intrusion of low-saline waters from the south, while during September by the high saline water from the north. The presence of various water masses [Arabian Sea High Salinity Water (ASHSW), Persian Gulf Water (PGW), Red Sea Water (RSW)] and their seasonal variations in the region is discussed and their decreasing influence towards the south is noted during both periods of observation. During the SWM, the dynamic topography showed the equator-ward flow of the West India Coastal Current (WICC) at the surface and a pole-ward coastal under current at sub-thermocline depth. During the SIM, surface circulation revealed the WICC flowing pole-ward north of 13°N, but equator-ward flow in the south, with a clockwise circulation around the Lakshadweep High.  相似文献   
599.
辽宁绥中海域海水和表层沉积物中重金属污染评价   总被引:1,自引:1,他引:0  
根据2009年10月的调查数据对辽宁绥中海域海水和表层沉积物中的重金属(砷、汞、铜、铅、锌和镉)进行了研究。用单因子指数评价法对海水中的重金属进行了评价,结果表明,海水中的Zn、Hg含量均超过《海水水质标准》(GB3097-1997)中Ⅰ类海水水质标准。采用《海洋沉积物质量》(GB 18668-2002)Ⅰ类海洋沉积物质量标准评价,表层沉积物中的As超标一倍以上。采用瑞典科学家Hkanson的潜在生态危害指数法进行评价,生态危害程度As>Hg>Cd>Cu>Zn>Pb。  相似文献   
600.
以城市污水处理厂的剩余污泥为材料,经过质子化处理制备成生物吸附剂,进行了吸附水溶液中活性红4(RR4)的研究.同时考察了吸附时间、溶液pH值、染料浓度、盐的浓度等因素对RR4吸附的影响.生物吸附剂对RR4的吸附所需平衡时间短(约22h),酸性条件利于吸附,碱性条件下则会发生解吸附(解吸附率高于87%),吸附等温曲线符合Langmuir和Freundlich模式,pH=1条件下生物吸附剂、活性碳、硅藻土对RR4的最大吸附量qm分别为35.66,20.48,1.82mg·g-1.RR4低浓度时盐对吸附不产生明显影响,当RR4高浓度时,盐对吸附有促进作用.研究结果表明,用质子化剩余污泥作生物吸附剂去除染料废水中RR4有实际应用的潜力,为剩余污泥的资源化提供了新途径.  相似文献   
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