Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers.A floor area ratio bonus is encouraged by the Chinese State Co...Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers.A floor area ratio bonus is encouraged by the Chinese State Council.In order to ensure the feasibility of a reward quota,residential buildings that met the requirement for energy efficiency during the official assessment in Ningbo in 2014 were selected as research objects.The amount of energy and water savings in terms of the Assessment Standard for Green Building is converted into carbon emissions.Carbon emissions of different star-rated green buildings are then measured in accordance with the actual water and power consumption of residential dwellings in 2014.A regression equation is set up concerning the floor area ratio and index for residential land per capita.A carbon emission-based method is proposed for measuring the reward quota associated with floor area ratio and recommendations are given for development using green building.展开更多
To study the seismic behavior of high strength concrete fi lled double-tube(CFDT) columns,each consisting of an external square steel tube and an internal circular steel tube,quasi-static tests on eight CFDT column sp...To study the seismic behavior of high strength concrete fi lled double-tube(CFDT) columns,each consisting of an external square steel tube and an internal circular steel tube,quasi-static tests on eight CFDT column specimens were conducted.The test variables included the width-to-thickness ratio(β1) and the area ratio(β2) of the square steel tube,the wall thickness of the circular steel tube,and the axial force(or the axial force ratio) applied to the CFDT columns.The test results indicate that for CFDT columns with a square steel tube with β1 of 50.1 and 24.5,local buckling of the specimen was found at a drift ratio of 1/150 and 1/50,respectively.The lateral force-displacement hysteretic loops of all specimens were plump and stable.Reducing the width-to-thickness ratio of the square steel tube,increasing its area ratio,or increasing the wall thickness of the internal circular steel tube,led to an increased fl exural strength and deformation capacity of the specimens.Increasing the design value of the axial force ratio from 0.8 to 1.0 may increase the fl exural strength of the specimens,while it may also decrease the ultimate deformation capacity of the specimen with β1 of 50.1.展开更多
Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading proper...Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading properties affect the outdoor thermal environment in a high-altitude plateau climate where few studies have been conducted.The measurements were conducted during summer and winter in a residential area in Lhasa,Tibet.Without natural shading such as trees,there is a positive correlation between Sky-view factor(SVF)and Physiological equivalent temperature(PET)during winter and a negative correlation during summer.When SVF exceeds 0.65 in summer,it may cause human discomfort.Compared to artificial shading such as a tensioned membrane,deciduous trees are superior at improving human comfort,as they can increase PET by 10.56℃ in winter and decrease it by 9.73℃ in summer.During summer,high-reflection water-permeable bricks can reduce the PET by 1.08℃,and lawns can reduce the mean rachation temperature(Tmrt)by 1.650C;however,the lawns may produce a microclimate with a high air temperature.The results from this paper can be used as a reference for landscape planning and design in residential areas in high-altitude cold-climate regions.展开更多
The safety of highways with a high ratio of bridges and tunnels is related to multiple factors,for example,the skid resistance of the pavement surface.In this study,the distribution of accidents under different condit...The safety of highways with a high ratio of bridges and tunnels is related to multiple factors,for example,the skid resistance of the pavement surface.In this study,the distribution of accidents under different conditions was calculated to investigate the relationship between the road skid resistance and the incidence of traffic accidents based on the traffic accident data of the Yuxiang highway.Statistical results show that weather conditions and road alignment may affect traffic accidents.The correlation analysis method was used to study the relationship between three factors and traffic accidents.The results show that road alignment,weather conditions and road skid resistance are related to the incidence of traffic accidents.The traffic accident prediction models were established based on back propagation neural network to verify the correlation analysis results.It is confirmed that road alignment,weather conditions and road skid resistance are the factors that affect traffic accidents.展开更多
High alumina slag is widely found in pyrometallurgical extractions of ferronickel,ferrochromium,and platinum group metals.The effects of MgO,Al_(2)O_(3),and CaO/SiO_(2) on the sulfur distribution ratio between high-al...High alumina slag is widely found in pyrometallurgical extractions of ferronickel,ferrochromium,and platinum group metals.The effects of MgO,Al_(2)O_(3),and CaO/SiO_(2) on the sulfur distribution ratio between high-alumina CaO–SiO_(2)–MgO–Al_(2)O_(3) slag and carbon-saturated iron were investigated.The slag consisted of Al_(2)O_(3) content in the range of 27.61–40.00 wt.%,CaO/SiO_(2) ratio of 0.8–1.1,and MgO content of 8–16 wt.%.The theoretical liquid areas of CaO–SiO_(2)–MgO–Al_(2)O_(3) slag were analyzed through the phase diagrams.The sulfur distribution ratio was measured via the slag–metal equilibrium technique at 1500ºC.It was observed that the sulfur distribution ratio increased with higher MgO content and higher CaO/SiO_(2) ratio largely due to the increase in free O^(2-)ions and the decrease in activity coefficient of sulfur ion in slag,but slightly decreased with the increasing Al_(2)O_(3) content because of the decrease in free O^(2-).展开更多
基金supported by Zhejiang Provincial Construction Research Projects(2015K150)Natural Science Foundation of Ningbo(2015A610302).
文摘Green building development in China relies mainly on compulsory measures that lack incentive policies to motivate the enthusiasm of real estate developers.A floor area ratio bonus is encouraged by the Chinese State Council.In order to ensure the feasibility of a reward quota,residential buildings that met the requirement for energy efficiency during the official assessment in Ningbo in 2014 were selected as research objects.The amount of energy and water savings in terms of the Assessment Standard for Green Building is converted into carbon emissions.Carbon emissions of different star-rated green buildings are then measured in accordance with the actual water and power consumption of residential dwellings in 2014.A regression equation is set up concerning the floor area ratio and index for residential land per capita.A carbon emission-based method is proposed for measuring the reward quota associated with floor area ratio and recommendations are given for development using green building.
基金the National Natural Science Foundation of China under Grants Nos.51261120377 and 51008173
文摘To study the seismic behavior of high strength concrete fi lled double-tube(CFDT) columns,each consisting of an external square steel tube and an internal circular steel tube,quasi-static tests on eight CFDT column specimens were conducted.The test variables included the width-to-thickness ratio(β1) and the area ratio(β2) of the square steel tube,the wall thickness of the circular steel tube,and the axial force(or the axial force ratio) applied to the CFDT columns.The test results indicate that for CFDT columns with a square steel tube with β1 of 50.1 and 24.5,local buckling of the specimen was found at a drift ratio of 1/150 and 1/50,respectively.The lateral force-displacement hysteretic loops of all specimens were plump and stable.Reducing the width-to-thickness ratio of the square steel tube,increasing its area ratio,or increasing the wall thickness of the internal circular steel tube,led to an increased fl exural strength and deformation capacity of the specimens.Increasing the design value of the axial force ratio from 0.8 to 1.0 may increase the fl exural strength of the specimens,while it may also decrease the ultimate deformation capacity of the specimen with β1 of 50.1.
文摘Landscape elements in residential areas can effectively improve the outdoor thermal environment,with different outcomes depending on the climate conditions.This study explores how the ground surface and shading properties affect the outdoor thermal environment in a high-altitude plateau climate where few studies have been conducted.The measurements were conducted during summer and winter in a residential area in Lhasa,Tibet.Without natural shading such as trees,there is a positive correlation between Sky-view factor(SVF)and Physiological equivalent temperature(PET)during winter and a negative correlation during summer.When SVF exceeds 0.65 in summer,it may cause human discomfort.Compared to artificial shading such as a tensioned membrane,deciduous trees are superior at improving human comfort,as they can increase PET by 10.56℃ in winter and decrease it by 9.73℃ in summer.During summer,high-reflection water-permeable bricks can reduce the PET by 1.08℃,and lawns can reduce the mean rachation temperature(Tmrt)by 1.650C;however,the lawns may produce a microclimate with a high air temperature.The results from this paper can be used as a reference for landscape planning and design in residential areas in high-altitude cold-climate regions.
基金supported by grants from the National Natural Science Foundation of China (Grant No.52008069)National&Local Joint Engineering Laboratory of Traffic Civil Engineering Materials (Grant No.LHSYS-2021-001).
文摘The safety of highways with a high ratio of bridges and tunnels is related to multiple factors,for example,the skid resistance of the pavement surface.In this study,the distribution of accidents under different conditions was calculated to investigate the relationship between the road skid resistance and the incidence of traffic accidents based on the traffic accident data of the Yuxiang highway.Statistical results show that weather conditions and road alignment may affect traffic accidents.The correlation analysis method was used to study the relationship between three factors and traffic accidents.The results show that road alignment,weather conditions and road skid resistance are related to the incidence of traffic accidents.The traffic accident prediction models were established based on back propagation neural network to verify the correlation analysis results.It is confirmed that road alignment,weather conditions and road skid resistance are the factors that affect traffic accidents.
基金The authors gratefully acknowledge the support from the National Natural Science Foundation of China Project(52104345)the Major Science and Technology Special Project of Yunnan Province(202002AB080001-1).
文摘High alumina slag is widely found in pyrometallurgical extractions of ferronickel,ferrochromium,and platinum group metals.The effects of MgO,Al_(2)O_(3),and CaO/SiO_(2) on the sulfur distribution ratio between high-alumina CaO–SiO_(2)–MgO–Al_(2)O_(3) slag and carbon-saturated iron were investigated.The slag consisted of Al_(2)O_(3) content in the range of 27.61–40.00 wt.%,CaO/SiO_(2) ratio of 0.8–1.1,and MgO content of 8–16 wt.%.The theoretical liquid areas of CaO–SiO_(2)–MgO–Al_(2)O_(3) slag were analyzed through the phase diagrams.The sulfur distribution ratio was measured via the slag–metal equilibrium technique at 1500ºC.It was observed that the sulfur distribution ratio increased with higher MgO content and higher CaO/SiO_(2) ratio largely due to the increase in free O^(2-)ions and the decrease in activity coefficient of sulfur ion in slag,but slightly decreased with the increasing Al_(2)O_(3) content because of the decrease in free O^(2-).
