Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate (DBP) was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration w...Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate (DBP) was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration were investigated. In addition, the activities of radicals on uncatalysed and catalysed ozonation were studied. The degradation intermediate products were followed and the kinetic of the ozonation were assessed as well. Results revealed that ozonation of DBP followed two mechanisms. Firstly, the reaction rate of direct ozonation was slower at lower pH, temperature, and ionic strength. Secondly, when these factors were increased for indirect radical reaction, higher percentage of DBP was removed with the increase of the initial ozone dosage and the decrease of the initial DBP concentration. In addition, tea-butanol, humic substances and Fe(Ⅱ) affected DBP ozonation through the radical pathway. It was determined that ozonation was restrained by adding tea-butanol for its radical inhibition effect. Furthermore, humic substances enhanced the reaction to some extent, but a slight negative effect would be encountered if the optimum dosage was exceeded. As a matter of fact, Mn(Ⅱ) affected the ozonation by "active sites" mechanism. In the experiment, three different kinds of intermediate products were produced during ozonation, but the amount of products for each one of them decreased as pH, temperature, ionic strength and initial ozone dosage increased. A kinetic equation of the reaction between ozone and DBP was obtained.展开更多
The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of ...The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of Chinese civilization. Using the field archaeological data and the sporo-pollens and the age data of the drilling cores, we analysed Neolithic cultural development and environmental evolution in the Huaihe River basin of Anhui. According to the combination of some research results in archaeology with environmental evolution research, this paper discusses the relationship between culture and environment in the Huaihe River basin of Anhui. The Neolithic cultural development was strongly impacted by the environmental change. The primitive culture (Shishanzi) was developed in the beginning of the Holocene Megathermal Period with distinct regional feature of the culture. From 6.5 kaBP to 5.5 kaBP, the climate changed warmer and wetter. The frequent occurrence of flood and waterlog due to such a climate regime and high sea level caused the earth's surface environment deteriorated in the Huaihe River basin of Anhui and the interruption of the Neolithic cultural development, hence a lack of archaeological sites. From 5.5 kaBP to 4.0 kaBP, the climate changed from wet to dry, the natural environment was propitious to human survival. Dawenkou Culture and Longshan Culture flourished in this period. The Neolithic cultural development, the number of the sites and their distribution characteristics of the sites in the study area differed apparently from those in Central China and Shandong Province.展开更多
Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were...Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were examined.Correlation analysis showed that similar correlations between tree-ring width chronologies and climatic factors demonstrated that radial growth responded to climate change on both slopes.The radial growth of L.chinensis was mainly limited by temperature,especially the growing season.In contrast,both chronologies were negatively correlated with precipitation in May of the previous year and April of the current year.Spatial climate-correlation analyses with gridded land-surface climate data revealed that our tree-ring width chronologies contained a strong regional temperature signal over much of northcentral and eastern China.Spatial correlation with seasurface temperature fields highlights the influence of the Pacific Ocean,Indian Ocean,and North Atlantic Ocean.Wavelet coherence analysis indicated the existence of some decadal and interannual cycles in the two tree-ring width chronologies.This may suggest the influences of El Nin˜o-Southern Oscillation and solar activity on tree growth in the Qinling Mountains.These findings will help us understand the growth response of L.chinensis to climate change in the Qinling region,and they provide critical information for future climate reconstructions based on this species in semi-humid regions.展开更多
Sustainable landscape is the only trend of future landscape development,it is of realistic significance to guide landscape architects to engage in sustainable landscape design.In this study,landscape design experience...Sustainable landscape is the only trend of future landscape development,it is of realistic significance to guide landscape architects to engage in sustainable landscape design.In this study,landscape design experience in recent years was summarized and analyzed by studying relevant design cases,then innovative design of sustainable landscapes integrating people-oriented,history and ecology was proposed to help landscape architects or beginners confused about the complex design techniques to figure out the design orientation.展开更多
Based on the samples collected from the west wall of the ABYT2004 at Yuhuicun Site in Bengbu, Anhui Province, the multi-environmental substitute indexes such as the grain-size, Rb/Sr, zircon crystal morphology and mag...Based on the samples collected from the west wall of the ABYT2004 at Yuhuicun Site in Bengbu, Anhui Province, the multi-environmental substitute indexes such as the grain-size, Rb/Sr, zircon crystal morphology and magnetic susceptibility were analyzed. The age of archaeological strata was determined by AMS^14C dating. According to the results, combined with the information of the ancient human activities and the cultural heritage data obtained from the Longshan cultural archaeological strata, it can be concluded that (1) Before 4500 aBP, the climate was humid and water level was high in the Huaihe River and its tributaries, the drainage basin and its surrounding areas were even flooded, so the site area was submerged and there were no human activities around the site. (2) About 4500 aBP, the climate began to become drier and water level of the Huaihe River and its tributaries began to decline, thus floodplain gradually appeared, Yuhuicun Site and Longshan Culture began to appear. (3) Around 4100 aBP, the climate was humid and rainfall was abundant, which resulted in frequent flood disasters in the whole Huaihe River Basin. (4) After 4100 aBP, the climate gradually transited to be cold and dry, agricultural production was constrained to reduce the food source, Yuhuicun Site was almost abandoned. (5) The environmental information in sedimentary strata and historical records based on ancient books agree with each other. In addition, Yuhuicun Site was related to Dayu Zhishui (Yu the Great in taming the floods) in ancient books.展开更多
Based on an in-depth survey of different typical areas that are selected in different regions and at different levels, this paper identifies the general characteristics of China's urbanization, the impacts that ec...Based on an in-depth survey of different typical areas that are selected in different regions and at different levels, this paper identifies the general characteristics of China's urbanization, the impacts that economic development driven by both exogenous and endogenous engines has on the spatial pattern of urbanization, and the two urbanization paths:gradient development and hierarchal advancement. By analyzing such factors as population growth, population mobility, and economic and industrial development, it sums up five spatial patterns for future urbanization development trends. Through the analyses on the three aspects:whereabouts of the present 260 million migrant workers and their families, whereabouts of the new-born population and new working-age rural population, and the migrant scale of the existing agricultural labors moving to non-agricultural industries, this paper predicts that China's urbanization rate will slow down in the next five to ten years, and will reach about 65 percent in around 2030. On the basis of the analyses, it puts forward that "Five-Six-Eleven" regional pattern of urbanization should be established to guide the overall strategy for spatial pattern optimization. To optimize the spatial pattern of urbanization, it proposes specific strategies including coordinated development of large, medium-sized, and small cities, and small towns, as well as urbanization development strategies of differentiation according to different classes and regions.展开更多
Based on the temporal-spatial distribution features of ancient settlement sites from the middle and late Neolithic Age to the Han dynasty in the Chaohu Lake Basin of Anhui Province, East China, using the methods of GI...Based on the temporal-spatial distribution features of ancient settlement sites from the middle and late Neolithic Age to the Han dynasty in the Chaohu Lake Basin of Anhui Province, East China, using the methods of GIS combined with the reconstructed paleoen- vironment by the records of lake sediment since Holocene, the transmutation of ancient set- tlements with response to environmental changes in this area has been discussed. Studies show that the main feature of transmutation of ancient settlements from the middle and late Neolithic Age to the Han Dynasty was that the distribution of settlements in this area changed from high altitudes to low ones and kept approaching the Chaohu Lake with the passage of time. These could be the response to the climate change from warm-moist to a relatively warm-dry condition during the middle Holocene, leading to the lake level fluctuations. The large area of exposed land provided enough space for human activities. These indicate that the above changes in geomorphologic evolution and hydrology influenced by climate condi- tions affected the transmutation of ancient settlements greatly. The distribution pattern of settlement sites was that the number of sites in the west was more than in the east. This pattern may be related to the geomorphologic conditions such as frequent channel shifting of the Yangtze River as well as flood disasters during the Holocene optimum. Therefore, climate change was the inducement of the transmutation of ancient settlements in the Chaohu Lake Basin, which exerted great influence on the distribution, expansion and development of the ancient settlements.展开更多
Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol(SOA) in the atmosphere,in addition,some toxic species are harmful to human health.Strict counte...Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol(SOA) in the atmosphere,in addition,some toxic species are harmful to human health.Strict countermeasures have been taken to fight air pollution since 2013,and total amount control of volatile organic compounds is being promoted in China at present.Therefore,it is important to understand the pollution situation and the control status of ambient benzene homologues in China.This paper reviews research progress from published papers on pollution characteristics,atmospheric photochemical reactivity,health risk assessment and source identification of ambient benzene homologues in recent years in China,and also summarizes policies and countermeasures for the control of ambient benzene homologues and the relevant achievements.The total ambient levels of benzene,toluene,ethylbenzene and xylenes(BTEX) shows a declining tendency from 2001 to 2016 in China.The mass concentrations of BTEX are generally higher in southern regions than in northern regions,and they present vertical decreasing variation characteristics with increasing altitude within the height range of about 5500 m.Toluene has the highest ozone formation potential and SOA formation potential both in urban areas and background areas,while benzene poses an obvious carcinogenic risk to the exposed adult populations in urban areas.Source identification of ambient benzene homologues suggested that local governments should adopt differentiated control strategies for ambient benzene homologues.Several recommendations are put forward for future research and policy-making on the control of ambient benzene homologues in China.展开更多
γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. At the same time, the des...γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.展开更多
Building heating,ventilation,and air conditioning(HVAC)systems consume large amounts of energy,and precise energy prediction is necessary for developing various energy-efficiency strategies.Energy prediction using dat...Building heating,ventilation,and air conditioning(HVAC)systems consume large amounts of energy,and precise energy prediction is necessary for developing various energy-efficiency strategies.Energy prediction using data-driven models has received increasing attention in recent years.Typically,two types of driven models are used for building energy prediction:sequential and parallel predictive models.The latter uses the historical energy of the target building as training data to predict future energy consumption.However,for newly built buildings or buildings without historical data records,the energy can be estimated using the parallel model,which employs the energy data of similar buildings as training data.The second predictive model is seldom studied because the model input feature is difficult to identify and collect.Herein,we propose a novel key-variable-based parallel HVAC energy predictive model.This model has informative input features(including meteorological data,occupancy activity,and key variables representing building and system characteristics)and a simple architecture.A general key-variable screening toolkit which was more versatile and flexible than present parametric analysis tools was developed to facilitate the selection of key variables for the parallel HVAC energy predictive model.A case study is conducted to screen the key variables of hotel buildings in eastern China,based on which a parallel chiller energy predictive model is trained and tested.The average cross-test error measured in terms of the coefficient of variation of the root mean square error(CV-RMSE)and normalized mean bias error(NMBE)of the parallel chiller energy predictive model is approximately 16%and 8.3%,which is acceptable for energy prediction without using historical energy data of the target building.展开更多
In this study, super-fine powdered activated carbon (SPAC) has been proposed and investigated as a novel catalyst for the catalytic ozonation of oxalate for the first time. SPAC was prepared from commercial granular...In this study, super-fine powdered activated carbon (SPAC) has been proposed and investigated as a novel catalyst for the catalytic ozonation of oxalate for the first time. SPAC was prepared from commercial granular activated carbon (GAC) by ball milling. SPAC exhibited high external surface area with a far greater member of meso- and macropores (563% increase in volume). The catalytic perfon,nances of activated carbons (ACs) of 8 sizes were compared and the rate constant for pseudo first-order total organic carbon removal increased from 0.012 mint to 0.568 min l (47-fold increase) with the decrease in size of AC from 20 to 40 mesh (863 ~tm) to SPAC (-1.0 tim). Furthermore, the diffusion resistance of SPAC decreased 17-fold compared with GAC. The ratio ofoxalate degradation by surface reaction increased by 57%. The rate of transformation of ozone to radicals by SPAC was 330 times that of GAC. The results suggest that a series of changes stimulated by ball milling, including a larger ratio of external surface area, less diffusion resistance, significant surface reaction and potential oxidized surface all contributed to enhancing catalytic ozonation performance. This study demonstrated that SPAC is a simple and effective catalyst fur enhancing catalytic ozonation efficacy.展开更多
基金The National Science Fund for Distinguished Young Scholars (No. 50225824), the National Natural Science Foundation of China(No. 50538090) and the Beijing Academic Innovation Group in Sustainable Water/Waste Recycle Technologies (No. BJE10016200611)
文摘Ozonation of synthetic water containing a type of endocrine disruptor-di-n-butyl phthalate (DBP) was examined. Key impact factors such as pH, temperature, ionic strength, ozone dosage and initial DBP concentration were investigated. In addition, the activities of radicals on uncatalysed and catalysed ozonation were studied. The degradation intermediate products were followed and the kinetic of the ozonation were assessed as well. Results revealed that ozonation of DBP followed two mechanisms. Firstly, the reaction rate of direct ozonation was slower at lower pH, temperature, and ionic strength. Secondly, when these factors were increased for indirect radical reaction, higher percentage of DBP was removed with the increase of the initial ozone dosage and the decrease of the initial DBP concentration. In addition, tea-butanol, humic substances and Fe(Ⅱ) affected DBP ozonation through the radical pathway. It was determined that ozonation was restrained by adding tea-butanol for its radical inhibition effect. Furthermore, humic substances enhanced the reaction to some extent, but a slight negative effect would be encountered if the optimum dosage was exceeded. As a matter of fact, Mn(Ⅱ) affected the ozonation by "active sites" mechanism. In the experiment, three different kinds of intermediate products were produced during ozonation, but the amount of products for each one of them decreased as pH, temperature, ionic strength and initial ozone dosage increased. A kinetic equation of the reaction between ozone and DBP was obtained.
基金National Natural Science Foundation of China, No.40271103 Natural Science Foundation of Anhui Provincial Education Department, No.2005KJ202/021
文摘The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of Chinese civilization. Using the field archaeological data and the sporo-pollens and the age data of the drilling cores, we analysed Neolithic cultural development and environmental evolution in the Huaihe River basin of Anhui. According to the combination of some research results in archaeology with environmental evolution research, this paper discusses the relationship between culture and environment in the Huaihe River basin of Anhui. The Neolithic cultural development was strongly impacted by the environmental change. The primitive culture (Shishanzi) was developed in the beginning of the Holocene Megathermal Period with distinct regional feature of the culture. From 6.5 kaBP to 5.5 kaBP, the climate changed warmer and wetter. The frequent occurrence of flood and waterlog due to such a climate regime and high sea level caused the earth's surface environment deteriorated in the Huaihe River basin of Anhui and the interruption of the Neolithic cultural development, hence a lack of archaeological sites. From 5.5 kaBP to 4.0 kaBP, the climate changed from wet to dry, the natural environment was propitious to human survival. Dawenkou Culture and Longshan Culture flourished in this period. The Neolithic cultural development, the number of the sites and their distribution characteristics of the sites in the study area differed apparently from those in Central China and Shandong Province.
基金funded by National Natural Science Foundation of China(No.31370587)
文摘Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were examined.Correlation analysis showed that similar correlations between tree-ring width chronologies and climatic factors demonstrated that radial growth responded to climate change on both slopes.The radial growth of L.chinensis was mainly limited by temperature,especially the growing season.In contrast,both chronologies were negatively correlated with precipitation in May of the previous year and April of the current year.Spatial climate-correlation analyses with gridded land-surface climate data revealed that our tree-ring width chronologies contained a strong regional temperature signal over much of northcentral and eastern China.Spatial correlation with seasurface temperature fields highlights the influence of the Pacific Ocean,Indian Ocean,and North Atlantic Ocean.Wavelet coherence analysis indicated the existence of some decadal and interannual cycles in the two tree-ring width chronologies.This may suggest the influences of El Nin˜o-Southern Oscillation and solar activity on tree growth in the Qinling Mountains.These findings will help us understand the growth response of L.chinensis to climate change in the Qinling region,and they provide critical information for future climate reconstructions based on this species in semi-humid regions.
文摘Sustainable landscape is the only trend of future landscape development,it is of realistic significance to guide landscape architects to engage in sustainable landscape design.In this study,landscape design experience in recent years was summarized and analyzed by studying relevant design cases,then innovative design of sustainable landscapes integrating people-oriented,history and ecology was proposed to help landscape architects or beginners confused about the complex design techniques to figure out the design orientation.
基金National Natural Science Foundation of China, No.40971115 No.40701190+1 种基金 National Key Technology R&D Program, No.2006BAK21B02 The Key Subject Foundation of Human Geography in West Anhui University The authors thank Prof. Zhou Kunshu of Institute of Geology and Geophysics, Chinese Academy of Sciences, Prof. Wang Fubao of Nanjing University, and Prof. Huang Run of West Anhui University for their constructive advices to the paper.
文摘Based on the samples collected from the west wall of the ABYT2004 at Yuhuicun Site in Bengbu, Anhui Province, the multi-environmental substitute indexes such as the grain-size, Rb/Sr, zircon crystal morphology and magnetic susceptibility were analyzed. The age of archaeological strata was determined by AMS^14C dating. According to the results, combined with the information of the ancient human activities and the cultural heritage data obtained from the Longshan cultural archaeological strata, it can be concluded that (1) Before 4500 aBP, the climate was humid and water level was high in the Huaihe River and its tributaries, the drainage basin and its surrounding areas were even flooded, so the site area was submerged and there were no human activities around the site. (2) About 4500 aBP, the climate began to become drier and water level of the Huaihe River and its tributaries began to decline, thus floodplain gradually appeared, Yuhuicun Site and Longshan Culture began to appear. (3) Around 4100 aBP, the climate was humid and rainfall was abundant, which resulted in frequent flood disasters in the whole Huaihe River Basin. (4) After 4100 aBP, the climate gradually transited to be cold and dry, agricultural production was constrained to reduce the food source, Yuhuicun Site was almost abandoned. (5) The environmental information in sedimentary strata and historical records based on ancient books agree with each other. In addition, Yuhuicun Site was related to Dayu Zhishui (Yu the Great in taming the floods) in ancient books.
文摘Based on an in-depth survey of different typical areas that are selected in different regions and at different levels, this paper identifies the general characteristics of China's urbanization, the impacts that economic development driven by both exogenous and endogenous engines has on the spatial pattern of urbanization, and the two urbanization paths:gradient development and hierarchal advancement. By analyzing such factors as population growth, population mobility, and economic and industrial development, it sums up five spatial patterns for future urbanization development trends. Through the analyses on the three aspects:whereabouts of the present 260 million migrant workers and their families, whereabouts of the new-born population and new working-age rural population, and the migrant scale of the existing agricultural labors moving to non-agricultural industries, this paper predicts that China's urbanization rate will slow down in the next five to ten years, and will reach about 65 percent in around 2030. On the basis of the analyses, it puts forward that "Five-Six-Eleven" regional pattern of urbanization should be established to guide the overall strategy for spatial pattern optimization. To optimize the spatial pattern of urbanization, it proposes specific strategies including coordinated development of large, medium-sized, and small cities, and small towns, as well as urbanization development strategies of differentiation according to different classes and regions.
基金Major Program of Natural Science Research at University of Anhui Province, No.ZD200908 National Sci ence and Technology Support Program, No.2010BAK67B02+1 种基金 National Natural Science Foundation of China, No.41010104005 No.40971115This work is supported by the Tracing Origin Project of Chinese Civilization. We thank Dr. An Ran and Dr. Heim. Jordan in Purdue University, USA, for their kind help and valuable discussions.
文摘Based on the temporal-spatial distribution features of ancient settlement sites from the middle and late Neolithic Age to the Han dynasty in the Chaohu Lake Basin of Anhui Province, East China, using the methods of GIS combined with the reconstructed paleoen- vironment by the records of lake sediment since Holocene, the transmutation of ancient set- tlements with response to environmental changes in this area has been discussed. Studies show that the main feature of transmutation of ancient settlements from the middle and late Neolithic Age to the Han Dynasty was that the distribution of settlements in this area changed from high altitudes to low ones and kept approaching the Chaohu Lake with the passage of time. These could be the response to the climate change from warm-moist to a relatively warm-dry condition during the middle Holocene, leading to the lake level fluctuations. The large area of exposed land provided enough space for human activities. These indicate that the above changes in geomorphologic evolution and hydrology influenced by climate condi- tions affected the transmutation of ancient settlements greatly. The distribution pattern of settlement sites was that the number of sites in the west was more than in the east. This pattern may be related to the geomorphologic conditions such as frequent channel shifting of the Yangtze River as well as flood disasters during the Holocene optimum. Therefore, climate change was the inducement of the transmutation of ancient settlements in the Chaohu Lake Basin, which exerted great influence on the distribution, expansion and development of the ancient settlements.
基金supported by the programs from Beijing Municipal Science&Technology Commission(No.Z181100005418015)the Finance Allocation Project of Ministry of Ecology and Environment of China(No.2110105)+2 种基金the Special Research Project for the National Environmental Protection Public Welfare Industry of China(No.201009032)the 2016 annual Graduation Practice Training Program of Beijing City Universitythe 2018 annual Graduation Practice Training Program of Beijing City University
文摘Benzene homologues are important chemical precursors to the formation of ground-level ozone and secondary organic aerosol(SOA) in the atmosphere,in addition,some toxic species are harmful to human health.Strict countermeasures have been taken to fight air pollution since 2013,and total amount control of volatile organic compounds is being promoted in China at present.Therefore,it is important to understand the pollution situation and the control status of ambient benzene homologues in China.This paper reviews research progress from published papers on pollution characteristics,atmospheric photochemical reactivity,health risk assessment and source identification of ambient benzene homologues in recent years in China,and also summarizes policies and countermeasures for the control of ambient benzene homologues and the relevant achievements.The total ambient levels of benzene,toluene,ethylbenzene and xylenes(BTEX) shows a declining tendency from 2001 to 2016 in China.The mass concentrations of BTEX are generally higher in southern regions than in northern regions,and they present vertical decreasing variation characteristics with increasing altitude within the height range of about 5500 m.Toluene has the highest ozone formation potential and SOA formation potential both in urban areas and background areas,while benzene poses an obvious carcinogenic risk to the exposed adult populations in urban areas.Source identification of ambient benzene homologues suggested that local governments should adopt differentiated control strategies for ambient benzene homologues.Several recommendations are put forward for future research and policy-making on the control of ambient benzene homologues in China.
基金financially supported by the Natural Science Foundation of Hubei Province, China(No. 2009CDB246)the Applied Basic Research Project of Wuhan City (No. 2015060101010068)
文摘γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.
基金This research is sponsored by China Southern Power Grid Technology Co.LTD(No.GDKJXM20200569).
文摘Building heating,ventilation,and air conditioning(HVAC)systems consume large amounts of energy,and precise energy prediction is necessary for developing various energy-efficiency strategies.Energy prediction using data-driven models has received increasing attention in recent years.Typically,two types of driven models are used for building energy prediction:sequential and parallel predictive models.The latter uses the historical energy of the target building as training data to predict future energy consumption.However,for newly built buildings or buildings without historical data records,the energy can be estimated using the parallel model,which employs the energy data of similar buildings as training data.The second predictive model is seldom studied because the model input feature is difficult to identify and collect.Herein,we propose a novel key-variable-based parallel HVAC energy predictive model.This model has informative input features(including meteorological data,occupancy activity,and key variables representing building and system characteristics)and a simple architecture.A general key-variable screening toolkit which was more versatile and flexible than present parametric analysis tools was developed to facilitate the selection of key variables for the parallel HVAC energy predictive model.A case study is conducted to screen the key variables of hotel buildings in eastern China,based on which a parallel chiller energy predictive model is trained and tested.The average cross-test error measured in terms of the coefficient of variation of the root mean square error(CV-RMSE)and normalized mean bias error(NMBE)of the parallel chiller energy predictive model is approximately 16%and 8.3%,which is acceptable for energy prediction without using historical energy data of the target building.
文摘In this study, super-fine powdered activated carbon (SPAC) has been proposed and investigated as a novel catalyst for the catalytic ozonation of oxalate for the first time. SPAC was prepared from commercial granular activated carbon (GAC) by ball milling. SPAC exhibited high external surface area with a far greater member of meso- and macropores (563% increase in volume). The catalytic perfon,nances of activated carbons (ACs) of 8 sizes were compared and the rate constant for pseudo first-order total organic carbon removal increased from 0.012 mint to 0.568 min l (47-fold increase) with the decrease in size of AC from 20 to 40 mesh (863 ~tm) to SPAC (-1.0 tim). Furthermore, the diffusion resistance of SPAC decreased 17-fold compared with GAC. The ratio ofoxalate degradation by surface reaction increased by 57%. The rate of transformation of ozone to radicals by SPAC was 330 times that of GAC. The results suggest that a series of changes stimulated by ball milling, including a larger ratio of external surface area, less diffusion resistance, significant surface reaction and potential oxidized surface all contributed to enhancing catalytic ozonation performance. This study demonstrated that SPAC is a simple and effective catalyst fur enhancing catalytic ozonation efficacy.