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991.
Reducing carbon leakage is one of the important reasons that was put forward by the EU for their border adjustment tax proposal.However,there are not many empirical evidences supporting significant carbon leakage in the EU carbonintensive industries.This paper applied the structural breakpoint test for the time series of import and export of cement,aluminum,and steel between EU and China.No significant structural changes were detected in the import and export of cement and aluminum.However,there proved to be two breakpoints,i.e.,2003 and 2008,in the import and export of steel,in which at the second point the overall level of steel import increased.Furthermore,Granger causality test was applied to the carbon price from European Climate Exchange and the import and export of steel.It was found that the carbon price was the Granger cause for the changes of steel import,but not the Granger cause for the export.The results of the study showed that the impacts of EU ETS on the EU carbon-intensive industries were limited.Among the three industries,partial evidence of carbon leakage was only found in the steel industry.Therefore,reducing carbon leakage could not serve as a convincing justification for border adjustment tax. 相似文献
992.
Regional development is the trend for future urbanization, and the urban circle is a highly efficient economic spatial pattern of regional development. This study selects statistical data of urban area population, GDP, and the output value of tertiary industry for seven cities in China – Jinan, Zibo, Tai’an, Laiwu, Dezhou, Liaocheng, and Binzhou – in the Shandong provincial capital urban circle from 2005 to 2009. It uses the principles and Zipf model, rank-size rule, and Lotka logarithmic model to analyze and study the hierarchical structure of the metropolitan system and economic development of the Shandong provincial capital urban circle. Based on the above research, this paper provides references for decision-making on enhancement of the metropolitan system structure, improvement in core city primacy index, the optimal adjustment of industrial structure and the optimal allocation of essential resources. 相似文献
993.
磷限制下光照和温度对水华鱼腥藻生长动力学的影响 总被引:2,自引:0,他引:2
磷、光照和温度是淡水水体藻类生长的关键环境因素,但磷限制下光照、温度交互对藻类生长动力学的影响鲜有报道.以水华鱼腥藻(Anabaena flosaquae)为研究对象,通过机制实验与模拟分析,发现光照条件恒定,磷限制下水华鱼腥藻的最适生长温度为20℃;温度条件恒定,磷限制下水华鱼腥藻的最适生长光照度为3 000 lx;但光照度过高,超过水华鱼腥藻光饱和点会抑制鱼腥藻的生长,生物积累量显著减少.通过拟合模型可知光热交互作用下水华鱼腥藻最适温度、光照度分别为21.03℃±1.55℃、2 675.12 lx±262.93 lx,该参数值接近春末夏初水体实际的光热条件.模型将为进一步预测水华鱼腥藻水华提供重要基础. 相似文献
994.
江西相山火山盆地位于中国东南部晚中生代火山-侵入杂岩带的最西端,具有明显的东西向构造域与北东向构造域叠加特征,其在扬子东南缘(浙赣段)中生代构造体制转换研究中具有重要意义。通过测定流纹英安岩和边缘相碎斑熔岩锆石LA-ICP-MS U-Pb年龄,研究其岩石地球化学、地质构造特征,认为相山火山盆地东西向构造与北东向构造的强烈转换时间为133.87±0.76 Ma至132.01±0.7 Ma之间,可代表扬子东南缘(浙赣段)中生代构造体制强烈转换时期。 相似文献
995.
Yeong Sheng Tey Mark Brindal 《Mitigation and Adaptation Strategies for Global Change》2014,19(8):1277-1293
Structural changes in the global commodity markets have particularly serious implications to the food security of import-dependent countries. Adapting importation policy to that global change is essential given that many commodities are imported to fulfill domestic demand. Using Singapore as a case study, this paper examines rice (Oryza) import allocation for seeking adaptive measures, which have broad implications to import-dependent countries. Its quarterly trade data (between 1999 and 2008) have been analyzed using an almost ideal demand system (AIDS) model. Our findings in respect to expenditure elasticity reveal that Singapore will continue its importation from its current range of suppliers, and add new import sources, fulfilling its national diversification strategy. New sources that located in different regions will also strengthen Singapore’s regional diversification strategy. Both national and regional diversification strategies enable any country to tap into associative import sources when unfavorable events deplete supply from a normally preferred supplier. In addition, the results in respect to own-price elasticity suggest that Thailand is Singapore’s primary preferred source while other exporters are secondary suppliers. Supported by the outputs of cross-price elasticity, secondary sources are substitutable. Within a diversified import portfolio, their competitive relationship gives an import-dependent country a strategic position to hedge against price manipulation and escalation, and to substitute expensive suppliers with cheaper alternatives. For these reasons, an import diversification policy is recommended both as an adaptive measure in response to the global change in commodity markets and, at the same time, as a mean for sustaining food security in import-dependent countries. 相似文献
996.
997.
Perfluorononanoic acid(PFNA) is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans and wildlife. There is a concern that this chemical might be a developmental toxicant and teratogen in various ecosystems. In the present study,the toxic effects of PFNA were evaluated in zebrafish(Danio rerio) embryos. One hour post-fertilization embryos were treated with 0, 25, 50, 100, 200, 300, 350, and 400 μmol/L PFNA for 96 hr in 6-well plates. Developmental phenotypes and hatching rates were observed and recorded. Nineteen genes related to oxidative stress and lipid metabolism were examined using Quantitative RT-PCR and confirmed by whole mount in situ hybridization(WISH). Results showed that PFNA delayed the development of zebrafish embryos, reduced the hatching rate, and caused ventricular edema and malformation of the spine. In addition, the amount of reactive oxygen species in the embryo bodies increased significantly after exposure to PFNA compared with that of the control group. The Quantitative RT-PCR and WISH experiments demonstrated that m RNA expression of the lfabp and ucp2 genes increased significantly while that of sod1 and mt-nd1 decreased significantly after PFNA exposure. The m RNA expression levels of gpx1 and mt-atp6 decreased significantly in the high concentration group. However, the m RNA expression levels of both ppara and pparg did not show any significant variation after exposure. These findings suggest that PFNA affected the development of zebrafish embryos at relatively low concentrations. 相似文献
998.
Jingyong Liu Jiewen Fu Xun''an Ning Shuiyu Sun Yujie Wang Wuming Xie Shaosong Huang Sheng Zhong 《环境科学学报(英文版)》2015,35(9):43-54
The effects of different chlorides and operational conditions on the distribution and speciation of six heavy metals (Pb, Zn, Cr, Cu, Mn and Ni) during sludge incineration were investigated using a simulated laboratory tubular-furnace reactor. A thermodynamic equilibrium investigation using the FactSage software was performed to compare the experimental results. The results indicate that the volatility of the target metals was enhanced as the chlorine concentration increased. Inorganic-Cl influenced the volatilization of heavy metals in the order of Pb > Zn > Cr > Cu > Mn > Ni. However, the effects of organic-Cl on the volatility of Mn, Pb and Cu were greater than the effects on Zn, Cr and Ni. With increasing combustion temperature, the presence of organic-Cl (PVC) and inorganic-Cl (NaCl) improved the transfer of Pb and Zn from bottom ash to fly ash or fuse gas. However, the presence of chloride had no obvious influence on Mn, Cu and Ni. Increased retention time could increase the volatilization rate of heavy metals; however, this effect was insignificant. During the incineration process, Pb readily formed PbSiO4 and remained in the bottom ash. Different Pb compounds, primarily the volatile PbCl2, were found in the gas phase after the addition of NaCl; the dominant Pb compounds in the gas phase after the addition of PVC were PbCl2, Pb(ClO4)2 and PbCl2O4. 相似文献
999.
采用热重-质谱(TG-MS)联用技术研究城市生活垃圾的热解特性以及Ca O的添加对垃圾热解过程和挥发分析出特性的影响。结果表明,城市生活垃圾在热解过程于低温区(240~385℃)的失重主要是由于垃圾样品中纤维素和半纤维素的分解以及部分塑料的低温分解,而发生在385~500℃间的第二失重峰主要是由于塑料和木质素组分的分解。添加Ca O有利于城市生活垃圾在低温区域的热解,并且能减少焦油组分的逸出,减弱CO2气体的逸出强度,促进CH4和CO气体的释放,但对C2H6气体的释放影响较小。 相似文献
1000.