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1.
Demographic urbanization caused great changes in scale of residents’ consumption and residents’ lifestyle and then impacted changes of regional household energy consumption. This paper expanded Logarithmic Mean Decomposition Index method through introducing variables of urbanization and residential consumption into the model. It also analyzed the influences of six factors as energy structure, energy intensity, population scale, urbanization, residential consumption, and consumption inhibit on regional household energy consumption. Results showed that in 2003–2012, impact of urbanization on regional household energy consumption of Chinese three areas was significantly higher than population size. The “population gathered in eastern region” phenomenon caused eastern region getting the largest population scale effect. Driving force of residential consumption on regional household energy consumption was much higher than the other five effects. Due to the comparative advantage of residential consumption compared with government consumption, investment, and net export, the decrease of consumption ratio promoted the growth of regional household energy consumption. Energy intensity in Chinese three regions kept reducing in 2003–2012. The progress of energy utilization technology slowed the growth of regional household energy consumption, and energy intensity effect was most significant in the central region.  相似文献   

2.
BackgroundEvidence on health effects of ultrafine particles (UFP) is still limited as they are usually not monitored routinely. The few epidemiological studies on UFP and (cause-specific) mortality so far have reported inconsistent results.ObjectivesThe main objective of the UFIREG project was to investigate the short-term associations between UFP and fine particulate matter (PM) < 2.5 μm (PM2.5) and daily (cause-specific) mortality in five European Cities. We also examined the effects of PM < 10 μm (PM10) and coarse particles (PM2.5–10).MethodsUFP (20–100 nm), PM and meteorological data were measured in Dresden and Augsburg (Germany), Prague (Czech Republic), Ljubljana (Slovenia) and Chernivtsi (Ukraine). Daily counts of natural and cardio-respiratory mortality were collected for all five cities. Depending on data availability, the following study periods were chosen: Augsburg and Dresden 2011–2012, Ljubljana and Prague 2012–2013, Chernivtsi 2013–March 2014. The associations between air pollutants and health outcomes were assessed using confounder-adjusted Poisson regression models examining single (lag 0–lag 5) and cumulative lags (lag 0–1, lag 2–5, and lag 0–5). City-specific estimates were pooled using meta-analyses methods.ResultsResults indicated a delayed and prolonged association between UFP and respiratory mortality (9.9% [95%-confidence interval: − 6.3%; 28.8%] increase in association with a 6-day average increase of 2750 particles/cm3 (average interquartile range across all cities)). Cardiovascular mortality increased by 3.0% [− 2.7%; 9.1%] and 4.1% [0.4%; 8.0%] in association with a 12.4 μg/m3 and 4.7 μg/m3 increase in the PM2.5- and PM2.5–10-averages of lag 2–5.ConclusionsWe observed positive but not statistically significant associations between prolonged exposures to UFP and respiratory mortality, which were independent of particle mass exposures. Further multi-centre studies are needed investigating several years to produce more precise estimates on health effects of UFP.  相似文献   

3.
In light of the rapid urbanization of the world’s population over the past decades, there is a growing concern about the environmental impacts of urban population growth. Rural–urban migration is a particularly important component of the urbanization process in developing countries and is often considered to be detrimental to urban environmental conditions. However, few studies have explicitly examined the presumed negative impacts of in-migration on the natural environment of cities. The continuously increasing volume of rural–urban labor migration in China since the early 1980s has formed the largest population flow in world history. This study links the existing literature on population–environment and urbanization–environment interactions by empirically assessing the relationship between rural–urban migration and urban air conditions in China. A two-period (2004 and 2010) longitudinal dataset for the 113 key environmental protection cities of China was constructed based on multiple data sources. We applied the STIRPAT equation using conventional and spatial panel regression models to examine whether rural–urban migration flows were associated with air pollution in cities. Results show a strong negative association of in-migration with urban air quality even after controlling for the effects of other population, affluence, and technology factors. Findings from this research can contribute to a better understanding of the environmental consequences of rural–urban migration in China, with broader implications for sustainable development research and policies.  相似文献   

4.
The objective of this research is to investigate the reduction in fuel consumption and emission in spark ignition engine using blended bioethanol-gasoline and novel radiator-tube heater. Different percentages of ethanol – 0, 5, 10, 15, 20, 25 and 30% – are employed. The blended fuel is then pre-heated by sending it into a tube-heater-installed upper tank radiator which has different shape. The results show a significant reduction in fuel consumption and emission in engine. The best economical fuel consumption occurs in the tube-heater with a fin pipe of 10 mm space at 2.153 × 10?3 cc per cycle or 5.632%. However, the most economical fuel consumption occurs when 25% of bioethanol is added to fuel at 3.175?×?10?3 per cycle. This decreases fuel consumption by 8.306%. The highest decrease in fuel consumption occurs when fuel blended with 25% of bioethanol and tube-heater of 10 mm 6.236?×?10?3 cc per cycle or 16.313% is combined. In terms of emission reduction, the tube-heater with a space of 20 mm between fins (Tube 20) using a fuel mixture of 25% ethanol and 75% gasoline produced the lowest CO emissions.  相似文献   

5.
Abstract

In this paper, the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries. Then, the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change, so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth. This study concludes that: First, there is a convergence in per capita GDP gap between China and the eight developed countries. With the convergence in per capita GDP gap, the energy intensity gap between China and eight different countries also converge, and the convergence rate of the latter is faster than that of the former, i.e. if the per capita GDP gap between China and the eight developed countries decreases by 1%, the energy intensity gap between them will correspondingly decrease by 1.552%. Second, the energy intensity decreases with the improvement of industrial structure, the rising of energy prices, the advances of technology, and the expansion of investment in fixed assets, and it slightly increases with the increase of FDI. Third, the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment, energy prices, and technological progress between China and eight developed countries, yet increases with the narrowing of the difference in FDI, and has no significant correlation with the difference in industrial structure. Fourth, the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap, whose economic mechanism is that the decisive factors, such as difference in investment, technology, and the competition mechanism of prices, which can determine the difference in economic growth, can significantly affect the energy intensity gap.  相似文献   

6.
Food traceability systems are capable of overcoming or alleviating problems caused by incomplete and asymmetric information on food markets.This study conducts an empirical analysis using 308 supermarket samples from China’s Beijing,Guangzhou,and Qingdao to determine the factors that influence supermarket behavior when operating traceability systems.The results show that operating profits(generated from food traceability systems),scale of operation,level of economic development(of a city),and government subsidies will positively affect the decision of supermarkets to use traceability systems.At the same time,government policies promoting food traceability systems should have a long-term role.  相似文献   

7.
It is a fact that in U.S. the immigration between rural areas and city areas is free, but in China this type of immigration is restricted by HUKOU system (Hukou, namely the household registration system, was designed to control rural-urban in China). All of those national policies in city areas are much better than those in rural areas, so those corresponding differences bring about great discrepancy of the economic status (mainly including GDP per person and income per resident) between rural and city areas in the same urban region, especially in different urban re- gions because the percentage of urban residents in those urban regions is in-equable. The present paper mainly researches the topic of relationship between the percentage of urban residents and the economic status in an urban region in China, including the relationship between the economic and the political functions of a settlement in China during the process of urbanization.  相似文献   

8.
Perfluoroalkyl substances (PFASs) are protein-binding blood-accumulating contaminants that may have detrimental toxicological effects on the early phases of mammalian development. To enable an evaluation of the potential health risks of PFAS exposure for polar bears (Ursus maritimus), an exposure assessment was made by examining plasma levels of PFASs in polar bear mothers in relation to their suckling cubs-of-the-year (~ 4 months old). Samples were collected at Svalbard in 1998 and 2008, and we investigated the between-year differences in levels of PFASs. Seven perfluorinated carboxylic acids (∑7PFCAs: PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA) and two perfluorinated sulfonic acids (∑2PFSAs: PFHxS and PFOS) were detected in the majority of the mothers and cubs from both years. In mothers and cubs, most PFCAs were detected in higher concentrations in 2008 than in 1998. On the contrary, levels of PFOS were lower in 2008 than in 1998, while levels of PFHxS did not differ between the two sampling years. PFOS was the dominating compound in mothers and cubs both in 1998 and in 2008. Concentration of PFHpA did not differ between mothers and cubs, while concentrations of PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFHxS, and PFOS were higher in mothers than in their cubs. Except from PFHpA, all compounds correlated significantly between mothers and their cubs. The mean cub to mother ratios ranged from 0.15 for PFNA to 1.69 for PFHpA. On average (mean ± standard error of mean), the levels of ∑7PFCAs and ∑2PFSAs in cubs were 0.24 ± 0.01 and 0.22 ± 0.01 times the levels in their mothers, respectively. Although maternal transfer appears to be a substantial source of exposure for the cubs, the low cub to mother ratios indicate that maternal transfer of PFASs in polar bears is relatively low in comparison with hydrophobic contaminants (e.g. PCBs). Because the level of several PFASs in mothers and cubs from both sampling years exceeded the levels associated with health effects in humans, our findings raise concern on the potential health effects of PFASs in polar bears from Svalbard. Effort should be made to examine the potential health effects of PFASs in polar bears.  相似文献   

9.
BackgroundExposure to bisphenol A (BPA), a known endocrine disruptor, has been demonstrated to affect fetal development in animal studies, but findings in human studies have been inconsistent.ObjectivesWe investigated whether maternal exposure to BPA during pregnancy is associated with an increased risk of infant low birth weight (LBW).MethodsA total 452 mother-infant pairs (113 LBW cases and 339 matched controls) were selected from the participants enrolled in the prospective Health Baby Cohort (HBC) in Wuhan city, China, during 2012–2014. BPA concentrations were measured in maternal urine samples collected at delivery, and the information of birth outcomes was retrieved from the medical records. A conditional logistic regression was used to evaluate the relationship between urinary BPA levels and LBW.ResultsMothers with LBW infants had significantly higher urinary BPA levels (median: 4.70 μg/L) than the control mothers (median: 2.25 μg/L) (p < 0.05). Increased risk of LBW was associated with higher maternal urinary levels of BPA [adjusted odds ratio (OR) = 3.13 for the medium tertile, 95% confidence interval (CI): 1.21, 8.08; adjusted OR = 2.49 for the highest tertile, 95% CI: 0.98, 6.36]. The association was more pronounced among female infants than among male infants, with a statistical evidence of heterogeneity in risk (p = 0.03).ConclusionsPrenatal exposure to higher levels of BPA may potentially increase the risk of delivering LBW infants, especially for female infants. This is the first case–control study to examine the association in China.  相似文献   

10.
Xiao  Lingbo  Fang  Xiuqi  Zhao  Wanyi 《Regional Environmental Change》2018,18(6):1721-1730
Regional Environmental Change - As a direct result of climate change and extreme weather events, refugee migration has attracted worldwide concern. In this study, we select the North China Plain...  相似文献   

11.
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