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941.
Currently, modeling studies tend to significantly underestimate observed space-based glyoxal(CHOCHO) vertical column densities(VCDs), implying the existence of missing sources of glyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for January and July 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors.In case 1, where the emissions of aromatic compounds were increased three-fold,improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in July were 3–5-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case 3, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of glyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes(a two-fold increase), the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in January but not in July.  相似文献   
942.
Cooking fume produced by oil and food at a high temperature releases large amount of fine particulate matter(PM) which have a potential hazard to human health. This chamber study investigated particle emission characteristics originated from using four types of oil(soybean oil, olive oil, peanut oil and lard) and different kinds of food materials(meat and vegetable). The corresponding emission factors(EFs) of number, mass, surface area and volume for particles were discussed. Temporal variation of size-fractionated particle concentration showed that olive oil produced the highest number PM concentration for the entire cooking process. Multiple path particle dosimetry(MPPD) model was performed to predict deposition in the human respiratory tract. Results showed that the pulmonary airway deposition fraction was the largest. It was also found that particles produced from olive oil led to the highest deposition. We strongly recommend minimizing the moisture content of ingredients before cooking and giving priority to the use of peanut oil instead of olive oil to reduce human exposure to PM.  相似文献   
943.
Promoting plug-in hybrid vehicles (PHEV) is one important option to mitigate greenhouse gas emissions and air pollutants for road transportation sector. In 2015, more than 220,000 new PHEVs were registered across the world, indicating a 25-fold growth during 2011–2015. However, more criticizes have been put forward against the current energy efficiency regulations for vehicles that are mostly depended on laboratory measurements. To better understand the real-world energy-saving and emission mitigation benefits from PHEVs, we conducted on-road testing experiments under various operating conditions for two in-use PHEVs in Beijing, China. Our results indicate that air condition usage, congested traffic conditions, and higher loading mass could significantly increase energy consumption and shorten actual all-electric distance for PHEVs. For example, the worst case (14.1 km) would occur under harshest usage conditions, which is lower by at least 35% than the claimed range over 20 km. In charge sustaining (CS) mode, real-world fuel consumption also presents a large range from 3.5 L/100 km to 6.3 L/100 km because of varying usage conditions. Furthermore, various vehicle users have significantly different travel profiles, which would lead to large heterogeneity of emission mitigation benefits among individual PHEV adopters. Therefore, this study suggests that the global policy makers should use real-world energy efficiency of emerging electrified powertrain techniques as criteria to formulate relevant regulations and supportive policies.  相似文献   
944.
绘出煤气化生产装置的硫元素平衡图,分析了硫化氢易中毒环节,提出防硫化氢泄漏、中毒的措施,为同行业防止硫化氢泄漏及中毒提供借鉴。  相似文献   
945.
脆弱性评估是企业防恐风险评估的关键环节。结合炼化企业装置设施特征,建立了以易损性、敏感性、承灾能力以及应急能力等4项一级指标、17项二级指标的防恐脆弱性评估指标体系,采用模糊层次分析法进行了防恐脆弱性半定量化评估,并根据评估结果提出了某炼化企业关键资产的安保策略改进方向。  相似文献   
946.
Objective: Road accidents are an important public health concern, and speeding is a major contributor. Although flow theory (FLT) is a valid model for understanding behavior, currently the nature of the roles and interplay of FLT constructs within the theory of planned behavior (TPB) framework when attempting to explain the determinants of motivations for intention to speed and speeding behavior of car drivers is not yet known. The study aims to synthesize TPB and FLT in explaining drivers of advanced vehicles intentions to speed and speed violation behaviors and evaluate factors that are critical for explaining intention and behavior.

Method: The hypothesized model was validated using a sample collected from 354 fully licensed drivers of advanced vehicles, involving 278 males and 76 females on 2 occasions separated by a 3-month interval. During the first of the 2 occasions, participants completed questionnaire measures of TPB and FLT variables. Three months later, participants' speed violation behaviors were assessed.

Results: The study observed a significant positive relationship between the constructs. The proposed model accounted for 51 and 45% of the variance in intention to speed and speed violation behavior, respectively. The independent predictors of intention were enjoyment, attitude, and subjective norm. The independent predictors of speed violation behavior were enjoyment, concentration, intention, and perceived behavioral control.

Conclusions: The findings suggest that safety interventions for preventing speed violation behaviors should be aimed at underlying beliefs influencing the speeding behaviors of drivers of advanced vehicles. Furthermore, perceived enjoyment is of equal importance to driver's intention, influencing speed violation behavior.  相似文献   

947.
Viviparity (giving birth to live young) in fossil reptiles has been known only in a few marine groups: ichthyosaurs, pachypleurosaurs, and mosasaurs. Here, we report a pregnant specimen of the Early Cretaceous Hyphalosaurus baitaigouensis, a species of Choristodera, a diapsid group known from unequivocal fossil remains from the Middle Jurassic to the early Miocene (about 165 to 20 million years ago). This specimen provides the first evidence of viviparity in choristoderan reptiles and is also the sole record of viviparity in fossil reptiles which lived in freshwater ecosystems. This exquisitely preserved specimen contains up to 18 embryos arranged in pairs. Size comparison with small free-living individuals and the straight posture of the posterior-most pair suggest that those embryos were at term and had probably reached parturition. The posterior-most embryo on the left side has the head positioned toward the rear, contrary to normal position, suggesting a complication that may have contributed to the mother’s death. Viviparity would certainly have freed species of Hyphalosaurus from the need to return to land to deposit eggs; taking this advantage, they would have avoided intense competition with contemporaneous terrestrial carnivores such as dinosaurs.  相似文献   
948.
文章在总结中国环境监理的特点和实践现状基础上,根据原料药项目的污染特点,分析原料药项目的环境监理流程及需注意的监理事项,以促进原料药项目环境监理工作的发展与交流,使环境监理工作更好地服务于环保管理。  相似文献   
949.
选用FeSO4和PAC(聚合氯化铝)两种絮凝剂,对浆染废水进行烧杯混凝试验,在此基础上考察了实际工程处理效果。结果表明,FeS04和PAC对浆染废水COD去除率和脱色率分别可达74.2%、68.1%和92.4%、87.8%。实际运行结果也显示,FeSO4和PAC均可作为浆染废水混凝预处理絮凝剂,其中FeSO4的混凝效果优于PAC,处理后出水pH和COD值满足厌氧酸化池微生物生长需要和负荷要求。  相似文献   
950.
CVM法对长江口海洋生态价值的评价应用   总被引:4,自引:1,他引:3  
运用CVM法探讨评价长江口海洋生态价值,结合长江口海洋产业的发展与生态环境实际,模拟市场条件进行主观意愿评价,阐述CVM法在长江口海洋生态价值评价应用中的可行性和有效性的同时,对CVM法使用时产生的偏差提出解决的方法,为长江口海洋产业绿色GDP核算提供科学方法和依据。  相似文献   
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