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791.
792.
Shanjun Li Yanyan Liu Junjie Zhang 《Journal of Environmental Economics and Management》2011,61(1):52-66
This paper examines the unexplored link between the prevalence of overweight and obesity and vehicle demand in the United States. Exploring annual sales data of new passenger vehicles at the model level in 48 U.S. counties from 1999 to 2005, we find that new vehicles demanded by consumers are less fuel-efficient on average as a larger share of people become overweight or obese. The OLS results show that a 10 percentage point increase in obesity and overweight reduces the average MPG of new vehicles demanded by 1.4 percent, an effect requiring a 12 cent increase in gasoline prices to counteract. The 2SLS results after controlling for possible endogeneity in overweight and obesity prevalence put those two numbers at 5 percent and 54 cent, respectively. These findings, robust to a variety of specifications, suggest that policies to reduce overweight and obesity can have additional benefits for energy security and the environment. 相似文献
793.
Acidic and basic properties and buffer capacity of airborne particulate matter in an urban area of Beijing 总被引:1,自引:0,他引:1
Mingqun Huo Qian Sun Yuhua Bai Peng Xie Zhaorong Liu Xuesong Wang Jinlong Li 《Environmental monitoring and assessment》2011,176(1-4):355-364
Particles with aerodynamic diameters <10 $\upmu $ m (PM10) and particles with aerodynamic diameters <2.5 $\upmu $ m (PM2.5) were sampled during summer 2006 in Beijing and mass concentrations, water-soluble ionic compounds concentrations, and acidic buffer capacity were analyzed. Results show that the mass concentration ranges of PM10 and PM2.5 were from 56.4 to 226.6 $\upmu $ g/m3 and from 31.3 to 200.7 $\upmu $ g/m3 during sampling days, respectively. Concentrations of F???, Cl???, NO $_{3}^{\,\,-}$ , NO $_{2}^{\,\,-}$ , SO $_{4}^{\,\,2-}$ , Ac???, Ca2?+?, Na?+?, K?+?, Mg2?+?, and NH $_{4}^{\,\,+}$ in particles were analyzed by ion chromatography. Microtitration was adapted to determine the acidic?Cbasic property and the change of the buffering systems in different pH of the aqueous solution in which the PM is suspended. The major alkalinity and buffer capacity of particles were analyzed and calculated. The average carbonate buffer capacity was 0.3 mmol/g in PM2.5 and 0.7 mmol/g in PM10. The average acetic acid buffer capacity was 0.1 mmol/g in PM2.5 and 0.3 mmol/g in PM10. Carbonate and acetic acid are the main species for the buffer capacity in the particle phase. The average mass of carbonate was 71.0 mg/g in PM10 and 46.7 mg/g in PM2.5. The average mass of acetic acid was 11.2 mg/g in PM2.5 and 20.0 mg/g in PM10. 相似文献
794.
Landscape planning and restoration in mine closure areas is not only an inevitable choice to sustain mining areas but also
an important path to maximize landscape resources and to improve ecological function in mine closure areas. The analysis of
the present mine development shows that many mines are unavoidably facing closures in China. This paper analyzes the periodic
impact of mining activities on landscapes and then proposes planning concepts and principles. According to the landscape characteristics
in mine closure areas, this paper classifies available landscape resources in mine closure areas into the landscape for restoration,
for limited restoration and for protection, and then summarizes directions for their uses. This paper establishes the framework
of spatial control planning and design of landscape elements from “macro control, medium allocation and micro optimization”
for the purpose of managing and using this kind of special landscape resources. Finally, this paper applies the theories and
methods to a case study in Wu’an from two aspects: the construction of a sustainable land-use pattern on a large scale and
the optimized allocation of typical mine landscape resources on a small scale. 相似文献
795.
The explosion and deflagration-to-detonation transition (DDT) in epoxy propane (E.P.) vapor/air mixture clouds under weak ignition conditions has been studied in an experimental tube of diameter 199 mm and length 29.6 m. E.P. vapor clouds were formed by injecting liquid E.P. into the experimental tube and evaporating of the fine E.P. droplets. The dimension and the evaporating process of the E.P. droplet were measured and analyzed. The E.P. vapor/air mixture clouds were ignited by an electric spark with an ignition energy of 40 J. The characteristics and the stages of the DDT process in the E.P. vapor/air mixtures have been studied and analyzed. A self-sustained detonation wave formed, as was evident from the existence of a transverse wave and a cellular structure. Moreover, a retonation wave formed during the DDT process in the E.P. vapor/air mixture. The influence of the E.P. vapor concentration on the DDT process has been studied. The minimum E.P. vapor concentration for the occurrence of the DDT in the E.P. vapor/air mixture has been evaluated and the variation of DDT distance with E.P. vapor concentration has been analyzed. 相似文献
796.
Chunhua Bai Guangdong Gong Qingming Liu Yahong Chen Guotao Niu 《Safety Science》2011,49(10):1349-1354
The explosion of the methane/air mixture and the methane/coal dust/air mixture under 40 J center spark ignition condition was experimentally studied in a large-scale system of 10 m3 vessel. Five pressure sensors were arranged in space with different distances from the ignition point. A high-speed camera system was used to record the growth of the flame. The maximum overpressure of the methane/air mixture appeared at 0.75 m away from the ignition point; the thickness of the flame was about 10 mm and the propagation speed of the flame fluctuated around 2.5 m/s with the methane concentration of 9.5%. The maximum overpressure of the methane/coal dust/air mixture appeared at 0.5 m. The flame had a structure of three concentric zones from outside were the red zone, the yellow illuminating zone and the bright white illuminating zone respectively; the thickness and the propagation speed of the flame increased gradually, the thickness of red zone and yellow illuminating zone reached 3.5 cm and 1 cm, the speed reached 9.2 m/s at 28 ms. 相似文献
797.
798.
799.
Yingjiu Bai Ikuyo Kaneko Hikaru Kobayashi Kazuo Kurihara Izuru Takayabu Hidetaka Sasaki Akihiko Murata 《Mitigation and Adaptation Strategies for Global Change》2014,19(5):589-614
Recently, local governments have an increasing need to take extensive and effective local measures to adapt to regional climate change, but have difficulty knowing how and when to adapt to such change. This study aims: 1) to characterize an efficient and cost-effective database management tool (DMT) for developing a Geographic Information System (GIS) based approach to using observed and projected data, for decision-making by non-expert government authorities, and 2) to document how DMT can be used to provide specialized yet understandable climate change information to assist local decision-makers in clarifying regional priorities within a wide array of adaptation options. The DMT combines climate change mapping, statistical GIS, and a vulnerability assessment. Okutama-machi, a 225.63 km2 sparsely populated mountainous region (2012 population 5,856) northwest of Tokyo, Japan, was chosen for this pilot study. In this paper, the most recent regional climate projections (5 km resolution) are transcribed into an understandable form for use by non-expert citizens who use the GIS-based DMT. Results illustrate qualitative agreement in projection of summer daily mean temperatures; the mean temperature increase at Okutama-machi is the greatest of any area in Tokyo. In comparing near future and future conditions, August monthly mean temperature will increase more than 0.7–0.9 °C and 2.8–2.9 °C, and monthly precipitation by 50 % and 25–41 %, respectively. However, the root mean square (RMS) errors and bias of percentage change for monthly precipitation in summertime are 26.8 % and 4.3 %, respectively. These data provide an early warning and have implications for local climate policy response. 相似文献
800.
选取临水河底部表层沉积物为研究对象,采用地质累积指数、潜在生态危害指数对其重金属污染进行评价。结果表明:沉积物Cr、Cd、Cu、Pb的含量介于203.971~412.363 mg/kg,浓度由高到低依次为Cr>Cu>Pb>Cd;Cd、Cu、Pb的空间变异系数较大,依次为82.8%、65.1%和43.1%,表明这3种重金属可能存在点源污染;Cr的空间变异系数较小,为28.2%,说明该重金属可能存在面源污染。地质累积指数表明:Cd和Cr的污染等级分别为3~5级和1~2级,为中度污染到极强度污染,Cu和Pb无污染。潜在生态危害指数RI值为280.54~879.27,污染程度为中等污染至很强污染。Cd为河流表层沉积物重金属污染的最大贡献者。 相似文献