[Objective] The aim was to study the willingness to accept compensation and compensation sharing of returning land for farming to forestry in Zhangjiakou and Chengde region.[Method] Based on the investigation of farm...[Objective] The aim was to study the willingness to accept compensation and compensation sharing of returning land for farming to forestry in Zhangjiakou and Chengde region.[Method] Based on the investigation of farmers’ willingness to accept ecological compensation in Zhangjiakou and Chengde region,farmers’ willingness to accept compensation was quantized,and the calculation model of sharing rate of ecological compensation was established,finally the sharing rate of ecological compensation was calculated choosing water supply quantity as reference.[Result] Farmers’ willingness to accept compensation in Zhangjiakou and Chengde region was 2 740.5 yuan/(hm2·a),and returned farmland area was 429 700 hm2 in 2008,so the willingness to accept ecological compensation was up to 1.178 billion yuan/a.In addition,the ecological compensation sharing rate of government was 37.60% in Beijing,42.75% in Tianjing and 19.64% in Tangshan,and their ecological compensation funds were 443,504 and 231 million yuan,respectively.[Conclusion] The study could provide important foundation for the establishment of ecological compensation standard and implementation of ecological compensation in Zhangjiakou and Chengde region.展开更多
[ Objective ] This study aimed to investigate the impacts of different instruments and methods on detection of water samples and evaluate the detection results and pollution share rate. [ Method] Concentrations of six...[ Objective ] This study aimed to investigate the impacts of different instruments and methods on detection of water samples and evaluate the detection results and pollution share rate. [ Method] Concentrations of six heavy metals in three surface water samples and three underground water samples were detected by AAS and ICP-AES to analyze the differences in detection results and calculate the pollution share rate of heavy metals. [Result] As a result, the pollution share rate of six heavy metals varied significantly. Calculation results of comprehensive pollution share rate based on the lower pollution index of the same heavy metal in the same water sample detected by two methods were different from the results using either method. Due to different detection limits of instruments, detection results of heavy metals in the same water sample were different, which affected the accuracy of environmental quality assessment. [ Conclusion ] The detected pollution share rate varies with different detection limits. Therefore, instruments and methods with lower detection limit should be used. To be specific, AAS is suitable for detection of Pb and Cd, while ICP is suitable for detection of Cu, Zn, Fe and Mn.展开更多
The successful application of new technologies such as remotely piloted aircraft systems,distributed electric propulsion systems,and automatic control systems on electric vertical take-off and landing(eVTOL)aircraft h...The successful application of new technologies such as remotely piloted aircraft systems,distributed electric propulsion systems,and automatic control systems on electric vertical take-off and landing(eVTOL)aircraft has prompted Urban Air Mobility(UAM)to be mentioned frequently.UAM is a newly raised transport mode of using eVTOL aircraft to transport people and cargo in urban areas,which is thought to share some of the traffic on the ground.One of the prerequisites for UAM to operate on a regular basis is that its demand can support the operating costs,so forecasting UAM demand is necessary.We conduct UAM demand forecasting based on the four-step method,focusing on improving the third-step modal split,and propose a demand forecasting model based on the logit model.The model combines a nested logit(NL)model with a multinomial logit(MNL)model to solve the problem of non-existent UAM sharing rates.We use Chengdu,China as an example,and focus on forecasting the UAM traffic demand in 2030 with the help of the four-step method.The results show that UAM is suitable for shared operation during the early stages.With a fully shared operation,the UAM share rate increases by 0.73%for every kilometer increase in distance.Moreover,UAM is more competitive than other modes for delivery distances exceeding 15 km.Finally,using the distributions of the share rate and traffic flow pattern from the simulation,we propose the routes that can be prioritized for UAM operations in Chengdu.展开更多
This work evaluates the influence of energy consumption on the future air quality in Beijing,using 2000 as the base year and 2008 as the target year.It establishes the emission inventory of primary PM_(10),SO_(2) and ...This work evaluates the influence of energy consumption on the future air quality in Beijing,using 2000 as the base year and 2008 as the target year.It establishes the emission inventory of primary PM_(10),SO_(2) and NO_(x) related to energy utilization in eight areas of Beijing.The air quality model was adopted to simulate the temporal and spatial distribution of each pollutant concentration in the eight urban areas.Their emission,concentration distribution,and sectoral share responsibility rate were analyzed,and air quality in 2008 was predicted.The industrial sector contributed above 40% of primary PM_(10) and SO_(2) resulting from energy consumption,while vehicles accounted for about 65% of NO_(x).According to the current policy and development trend,air quality in the eight urban areas could become better in 2008 when the average concentrations of primary PM_(10),SO_(2) and NO_(2) related to energy utilization at each monitored site are predicted to be about 25,50 and 51μg/m^(3),respectively.展开更多
基金Supported by Science and Technology Planning Project of Hebei Province (09276710D)Project of Hebei Academy of Sciences (10113,10927)Key Subject Construction of High Institutions in Hebei Province
文摘[Objective] The aim was to study the willingness to accept compensation and compensation sharing of returning land for farming to forestry in Zhangjiakou and Chengde region.[Method] Based on the investigation of farmers’ willingness to accept ecological compensation in Zhangjiakou and Chengde region,farmers’ willingness to accept compensation was quantized,and the calculation model of sharing rate of ecological compensation was established,finally the sharing rate of ecological compensation was calculated choosing water supply quantity as reference.[Result] Farmers’ willingness to accept compensation in Zhangjiakou and Chengde region was 2 740.5 yuan/(hm2·a),and returned farmland area was 429 700 hm2 in 2008,so the willingness to accept ecological compensation was up to 1.178 billion yuan/a.In addition,the ecological compensation sharing rate of government was 37.60% in Beijing,42.75% in Tianjing and 19.64% in Tangshan,and their ecological compensation funds were 443,504 and 231 million yuan,respectively.[Conclusion] The study could provide important foundation for the establishment of ecological compensation standard and implementation of ecological compensation in Zhangjiakou and Chengde region.
文摘[ Objective ] This study aimed to investigate the impacts of different instruments and methods on detection of water samples and evaluate the detection results and pollution share rate. [ Method] Concentrations of six heavy metals in three surface water samples and three underground water samples were detected by AAS and ICP-AES to analyze the differences in detection results and calculate the pollution share rate of heavy metals. [Result] As a result, the pollution share rate of six heavy metals varied significantly. Calculation results of comprehensive pollution share rate based on the lower pollution index of the same heavy metal in the same water sample detected by two methods were different from the results using either method. Due to different detection limits of instruments, detection results of heavy metals in the same water sample were different, which affected the accuracy of environmental quality assessment. [ Conclusion ] The detected pollution share rate varies with different detection limits. Therefore, instruments and methods with lower detection limit should be used. To be specific, AAS is suitable for detection of Pb and Cd, while ICP is suitable for detection of Cu, Zn, Fe and Mn.
基金supported by the National Natural Science Foundation of China(Grants No.41971359)Thanks to the Chengdu Traffic Management Bureau for providing data support for this article.
文摘The successful application of new technologies such as remotely piloted aircraft systems,distributed electric propulsion systems,and automatic control systems on electric vertical take-off and landing(eVTOL)aircraft has prompted Urban Air Mobility(UAM)to be mentioned frequently.UAM is a newly raised transport mode of using eVTOL aircraft to transport people and cargo in urban areas,which is thought to share some of the traffic on the ground.One of the prerequisites for UAM to operate on a regular basis is that its demand can support the operating costs,so forecasting UAM demand is necessary.We conduct UAM demand forecasting based on the four-step method,focusing on improving the third-step modal split,and propose a demand forecasting model based on the logit model.The model combines a nested logit(NL)model with a multinomial logit(MNL)model to solve the problem of non-existent UAM sharing rates.We use Chengdu,China as an example,and focus on forecasting the UAM traffic demand in 2030 with the help of the four-step method.The results show that UAM is suitable for shared operation during the early stages.With a fully shared operation,the UAM share rate increases by 0.73%for every kilometer increase in distance.Moreover,UAM is more competitive than other modes for delivery distances exceeding 15 km.Finally,using the distributions of the share rate and traffic flow pattern from the simulation,we propose the routes that can be prioritized for UAM operations in Chengdu.
基金This work was supported by the Foundation of the World Bank and Global Environment Facility(Grant No.60K04772).
文摘This work evaluates the influence of energy consumption on the future air quality in Beijing,using 2000 as the base year and 2008 as the target year.It establishes the emission inventory of primary PM_(10),SO_(2) and NO_(x) related to energy utilization in eight areas of Beijing.The air quality model was adopted to simulate the temporal and spatial distribution of each pollutant concentration in the eight urban areas.Their emission,concentration distribution,and sectoral share responsibility rate were analyzed,and air quality in 2008 was predicted.The industrial sector contributed above 40% of primary PM_(10) and SO_(2) resulting from energy consumption,while vehicles accounted for about 65% of NO_(x).According to the current policy and development trend,air quality in the eight urban areas could become better in 2008 when the average concentrations of primary PM_(10),SO_(2) and NO_(2) related to energy utilization at each monitored site are predicted to be about 25,50 and 51μg/m^(3),respectively.