Hydropower is a clean,renewable,and environmentally friendly source of energy.It produces 3930(TW·h)·a–1,and yields 16% of the world's generated electricity and about 78% of renewable electricity genera...Hydropower is a clean,renewable,and environmentally friendly source of energy.It produces 3930(TW·h)·a–1,and yields 16% of the world's generated electricity and about 78% of renewable electricity generation(in 2015).Hydropower and climate change show a double relationship.On the one hand,as an important renewable energy resource,hydropower contributes significantly to the avoidance of greenhouse gas(GHG) emissions and to the mitigation of global warming.On the other hand,climate change is likely to alter river discharge,impacting water availability and hydropower generation.Hydropower contributes significantly to the reduction of GHG emissions and to energy supply security.Compared with conventional coal power plants,hydropower prevents the emission of about 3 GT CO2 per year,which represents about 9% of global annual CO2 emissions.Hydropower projects may also have an enabling role beyond the electricity sector,as a financing instrument for multipurpose reservoirs and as an adaptive measure regarding the impacts of climate change on water resources,because regulated basins with large reservoir capacities are more resilient to water resource changes,less vulnerable to climate change,and act as a storage buffer against climate change.At the global level,the overall impact of climate change on existing hydropower generation may be expected to be small,or even slightly positive.However,there is the possibility of substantial variations across regions and even within countries.In conclusion,the general verdict on hydropower is that it is a cheap and mature technology that contributes significantly to climate change mitigation,and could play an important role in the climate change adaptation of water resource availability.However,careful attention is necessary to mitigate the substantial environmental and social costs.Roughly more than a terawatt of capacity could be added in upcoming decades.展开更多
This paper aims to provide an overall image in terms of low carbon society （LCS） and its development in China. It mainly introduced and analyzed low carbon development which was addressed as crucial initiative for i...This paper aims to provide an overall image in terms of low carbon society （LCS） and its development in China. It mainly introduced and analyzed low carbon development which was addressed as crucial initiative for implementation of LCS in China. A comparative analysis was carried out on concepts and experiences of LCS between China and developed countries. The trends and characteristics of CO2 emissions in China have also been analyzed. Because of large amount of CO2 emissions generated in the production process and relatively small amount of CO2 emissions in the consumption process, China is facing a severe challenge of imbalance in economic growth and CO2 emissions. If the consumption and production pattern of developed countries are duplicated, China is very likely to experience a development pattern of boosting economic growth and improving living standards significantly but meanwhile risking and suffering by large amount of resources consumption and CO2 emissions. Thus, a comprehensive, systematic and scientific scheme for implementing a low carbon society is urgently needed in China. Through literature research, mainstream perspectives of scholars with respect to development of LCS are concluded. In the meantime, CO2 emissions reduction target, carbon taxation and different debated issues are also presented. The achievements, China has rflade, consist of concrete actions taken by local governments, some new policies and regulations for carbon reduction at national level, in particular energy-saving and renewable energy policies proposed in the l lth Five-Year Plan （2005-2010）. Carbon trading markets and carbon capture and starage technology have also made progress in China. There are still many limitations and barriers remaining and in need to be solved in the next steps.展开更多
Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is...Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is not suitable for the rapid detection in daily scientific research. Besides, the assay methods of SAL-Na reported by literature are not suitable for quantification due to the interference of various excipients. Consequently, the deep study on biological mechanism of SAL-Na is hindered by its assay method. In the present study, we aimed to establish an ultraviolet visible（UV-vis） spectrophotometric method to determine the content of SAL-Na in the liposomes. The first approach was a UV spectrophotometry, in which SAL-Na was dissolved in ethanol and then detected at 287 nm. Although the standard curve measured at 287 nm by UV method had good linearity, the quantification limitation was too high to meet the requirement in determining SAL-Na in the liposomes. In addition, the membrane materials in the liposomes severely affected the measurement. The second one was an improved UV-vis spectrophotometry by vanillin derivatization. In this method, SAL-Na was dissolved in 95% ethanol, mixed with vanillin test solution and heated at 72 ℃ for 40 min for derivatization. After cooling down to room temperature, the solution was detected using UV-vis spectrophotometer at 526 nm. This method could be used to accurately determine the content of SAL-Na at lower concentration, and the absorbance value was stable for 5 d at least. Moreover, the membrane materials of the liposomes did not affect the absorbance of SAL-Na at 526 nm. The precision and recovery studies demonstrated that the vanillin derivatization approach was stable and precise in assaying SAL-Na. In conclusion, the UV-vis spectrophotometry by vanillin derivatization could be used for measuring SAL-Na in the liposomes, thereby laying a foundation for deep study of the biological mechanism of SAL-Na in the liposomes.展开更多
文摘Hydropower is a clean,renewable,and environmentally friendly source of energy.It produces 3930(TW·h)·a–1,and yields 16% of the world's generated electricity and about 78% of renewable electricity generation(in 2015).Hydropower and climate change show a double relationship.On the one hand,as an important renewable energy resource,hydropower contributes significantly to the avoidance of greenhouse gas(GHG) emissions and to the mitigation of global warming.On the other hand,climate change is likely to alter river discharge,impacting water availability and hydropower generation.Hydropower contributes significantly to the reduction of GHG emissions and to energy supply security.Compared with conventional coal power plants,hydropower prevents the emission of about 3 GT CO2 per year,which represents about 9% of global annual CO2 emissions.Hydropower projects may also have an enabling role beyond the electricity sector,as a financing instrument for multipurpose reservoirs and as an adaptive measure regarding the impacts of climate change on water resources,because regulated basins with large reservoir capacities are more resilient to water resource changes,less vulnerable to climate change,and act as a storage buffer against climate change.At the global level,the overall impact of climate change on existing hydropower generation may be expected to be small,or even slightly positive.However,there is the possibility of substantial variations across regions and even within countries.In conclusion,the general verdict on hydropower is that it is a cheap and mature technology that contributes significantly to climate change mitigation,and could play an important role in the climate change adaptation of water resource availability.However,careful attention is necessary to mitigate the substantial environmental and social costs.Roughly more than a terawatt of capacity could be added in upcoming decades.
基金supported by the National Natural Science Foundation of China (No. 41101500)
文摘This paper aims to provide an overall image in terms of low carbon society （LCS） and its development in China. It mainly introduced and analyzed low carbon development which was addressed as crucial initiative for implementation of LCS in China. A comparative analysis was carried out on concepts and experiences of LCS between China and developed countries. The trends and characteristics of CO2 emissions in China have also been analyzed. Because of large amount of CO2 emissions generated in the production process and relatively small amount of CO2 emissions in the consumption process, China is facing a severe challenge of imbalance in economic growth and CO2 emissions. If the consumption and production pattern of developed countries are duplicated, China is very likely to experience a development pattern of boosting economic growth and improving living standards significantly but meanwhile risking and suffering by large amount of resources consumption and CO2 emissions. Thus, a comprehensive, systematic and scientific scheme for implementing a low carbon society is urgently needed in China. Through literature research, mainstream perspectives of scholars with respect to development of LCS are concluded. In the meantime, CO2 emissions reduction target, carbon taxation and different debated issues are also presented. The achievements, China has rflade, consist of concrete actions taken by local governments, some new policies and regulations for carbon reduction at national level, in particular energy-saving and renewable energy policies proposed in the l lth Five-Year Plan （2005-2010）. Carbon trading markets and carbon capture and starage technology have also made progress in China. There are still many limitations and barriers remaining and in need to be solved in the next steps.
基金National Science Foundation of China(Grant No.81673367)
文摘Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is not suitable for the rapid detection in daily scientific research. Besides, the assay methods of SAL-Na reported by literature are not suitable for quantification due to the interference of various excipients. Consequently, the deep study on biological mechanism of SAL-Na is hindered by its assay method. In the present study, we aimed to establish an ultraviolet visible（UV-vis） spectrophotometric method to determine the content of SAL-Na in the liposomes. The first approach was a UV spectrophotometry, in which SAL-Na was dissolved in ethanol and then detected at 287 nm. Although the standard curve measured at 287 nm by UV method had good linearity, the quantification limitation was too high to meet the requirement in determining SAL-Na in the liposomes. In addition, the membrane materials in the liposomes severely affected the measurement. The second one was an improved UV-vis spectrophotometry by vanillin derivatization. In this method, SAL-Na was dissolved in 95% ethanol, mixed with vanillin test solution and heated at 72 ℃ for 40 min for derivatization. After cooling down to room temperature, the solution was detected using UV-vis spectrophotometer at 526 nm. This method could be used to accurately determine the content of SAL-Na at lower concentration, and the absorbance value was stable for 5 d at least. Moreover, the membrane materials of the liposomes did not affect the absorbance of SAL-Na at 526 nm. The precision and recovery studies demonstrated that the vanillin derivatization approach was stable and precise in assaying SAL-Na. In conclusion, the UV-vis spectrophotometry by vanillin derivatization could be used for measuring SAL-Na in the liposomes, thereby laying a foundation for deep study of the biological mechanism of SAL-Na in the liposomes.
