Combined with a digital bored photography system and in-situ statistics concerning the joints and fissures of both ore-body and surrounding rock,a 2D discrete model was constructed using UDEC.The stress field and disp...Combined with a digital bored photography system and in-situ statistics concerning the joints and fissures of both ore-body and surrounding rock,a 2D discrete model was constructed using UDEC.The stress field and displacement field changes of different sublevel stoping systems were also studied.Changes in the overlying rock strata settlement pattern has been analyzed and validated by in-situ monitoring data.The results show that:in the caving process,there exists an obvious delay and jump for the overlying rock strata displacement over time,and a stable arch can be formed in the process of caving,which leads to hidden goafs.Disturbed by the mining activity,a stress increase occurred in both the hanging wall and the foot wall,demonstrating a hump-shaped distribution pattern.From the comparison between simulation results and in-situ monitoring results,land subsidence shows a slow-development,suddenfailure,slow-development cycle pattern,which leads eventually to a stable state.This pattern validates the existence of balanced arch and hidden goafs.展开更多
Drawn on the data collected by surveying 1 340 urban households from six cities in China, this paper estimates the impacts of demographic structure and population aging on household meat consumption, by jointly consid...Drawn on the data collected by surveying 1 340 urban households from six cities in China, this paper estimates the impacts of demographic structure and population aging on household meat consumption, by jointly considering meat consumed at home and away from home. Based on the trajectories of population, a simple simulation on meat demand trend in China is conducted subsequently. The results suggest： 1） Meat consumed away from home averagely accounts for near 30% of household total meat consumption in terms of quantity, so that its omission likely leads to a significant underestimate of total meat consumption and misunderstanding the driving forces; 2） population aging significantly and negatively affects per capita meat consumption, suggesting that the expected meat demand in China without considering population aging will be overestimated. The findings from this study have important implications for better understanding the relative issues on China＇s meat consumption under the situation of population aging.展开更多
The 21 cm intensity mapping(IM)technique provides us with an efficient way to observe the cosmic large-scale structure(LSS).From the LSS data,one can use the baryon acoustic oscillation and redshift space distortion t...The 21 cm intensity mapping(IM)technique provides us with an efficient way to observe the cosmic large-scale structure(LSS).From the LSS data,one can use the baryon acoustic oscillation and redshift space distortion to trace the expansion and growth history of the universe,and thus measure the dark energy parameters.In this paper,we make a forecast for cosmological parameter estimation with the synergy of three 21 cm IM experiments.Specifically,we adopt a novel joint survey strategy,FAST(0<z<0.35)+SKA1-MID(0.35<z<0.8)+HIRAX(0.8<z<2.5),to measure dark energy.We simulate the 21 cm IM observations under the assumption of excellent foreground removal.We find that the synergy of three experiments could place quite tight constraints on cosmological parameters.For example,it providesσ(?m)=0.0039 andσ(H0)=0.27 km s^(-1) Mpc^(-1) in theΛCDM model.Notably,the synergy could break the cosmological parameter degeneracies when constraining the dynamical dark energy models.Concretely,the joint observation offersσ(w)=0.019 in the wCDM model,andσ(w0)=0.085 andσ(wa)=0.32 in the w0waCDM model.These results are better than or equal to those given by CMB+BAO+SN.In addition,when the foreground removal efficiency is relatively low,the strategy still performs well.Therefore,the 21 cm IM joint survey strategy is promising and worth pursuing.展开更多
This study introduces the‘Zero-Point Boundary’method to map the 2013 Typhoon Haiyan storm surge in coastal eastern Leyte.Utilising the‘Rivera Dispersive Wave Model’or RDM,we interpolated simulated storm surge and ...This study introduces the‘Zero-Point Boundary’method to map the 2013 Typhoon Haiyan storm surge in coastal eastern Leyte.Utilising the‘Rivera Dispersive Wave Model’or RDM,we interpolated simulated storm surge and wave height data,subtracting them from a 5-m resolution digital terrain model raster provided by the National Mapping and Resource Information Authority(NAMRIA)to determine inundation limits and depths relative to the average Filipino male height(i.e.,165 cm).Validation against the 2013 joint survey conducted by the Japan Society of Civil Engineers(JSCE)and the Philippine Institute of Civil Engineers(PICE)showed an 81%accuracy rate when identifying water limit locations in Tacloban City,suggesting potential for future forecasting.However,the absence of compoundflooding consideration in the simulations may have influenced this rate.Overall,this study underscores the importance of accurate modelling and communication in hazard mapping for enhancing preparedness and mitigation efforts,emphasising a balanced approach to risk perception.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51374033)the Doctoral Program of Higher Education Research Fund(No.20120006110022)the Chenchao Iron Mine and the technical support of Itasca
文摘Combined with a digital bored photography system and in-situ statistics concerning the joints and fissures of both ore-body and surrounding rock,a 2D discrete model was constructed using UDEC.The stress field and displacement field changes of different sublevel stoping systems were also studied.Changes in the overlying rock strata settlement pattern has been analyzed and validated by in-situ monitoring data.The results show that:in the caving process,there exists an obvious delay and jump for the overlying rock strata displacement over time,and a stable arch can be formed in the process of caving,which leads to hidden goafs.Disturbed by the mining activity,a stress increase occurred in both the hanging wall and the foot wall,demonstrating a hump-shaped distribution pattern.From the comparison between simulation results and in-situ monitoring results,land subsidence shows a slow-development,suddenfailure,slow-development cycle pattern,which leads eventually to a stable state.This pattern validates the existence of balanced arch and hidden goafs.
基金financial support from the National Natural Science Foundation of China(71273009)pUSDA,Economic Research Service,Cooperative Agreement(58-3000-7-0060)+2 种基金USDA,the Agricultural Food Research Initiative of the National Institute of Food and Agriculture(2010-65400-20489)USDA,Foreign Agricultural Service,th Emerging Markets Program Grant(2010-72)Chinese Universities Scientific Fund(2014RC017)
文摘Drawn on the data collected by surveying 1 340 urban households from six cities in China, this paper estimates the impacts of demographic structure and population aging on household meat consumption, by jointly considering meat consumed at home and away from home. Based on the trajectories of population, a simple simulation on meat demand trend in China is conducted subsequently. The results suggest： 1） Meat consumed away from home averagely accounts for near 30% of household total meat consumption in terms of quantity, so that its omission likely leads to a significant underestimate of total meat consumption and misunderstanding the driving forces; 2） population aging significantly and negatively affects per capita meat consumption, suggesting that the expected meat demand in China without considering population aging will be overestimated. The findings from this study have important implications for better understanding the relative issues on China＇s meat consumption under the situation of population aging.
基金supported by the National SKA Program of China(Grant Nos.2022SKA0110200,and 2022SKA0110203)National Natural Science Foundation of China(Grant Nos.11975072,11835009,and 11875102)。
文摘The 21 cm intensity mapping(IM)technique provides us with an efficient way to observe the cosmic large-scale structure(LSS).From the LSS data,one can use the baryon acoustic oscillation and redshift space distortion to trace the expansion and growth history of the universe,and thus measure the dark energy parameters.In this paper,we make a forecast for cosmological parameter estimation with the synergy of three 21 cm IM experiments.Specifically,we adopt a novel joint survey strategy,FAST(0<z<0.35)+SKA1-MID(0.35<z<0.8)+HIRAX(0.8<z<2.5),to measure dark energy.We simulate the 21 cm IM observations under the assumption of excellent foreground removal.We find that the synergy of three experiments could place quite tight constraints on cosmological parameters.For example,it providesσ(?m)=0.0039 andσ(H0)=0.27 km s^(-1) Mpc^(-1) in theΛCDM model.Notably,the synergy could break the cosmological parameter degeneracies when constraining the dynamical dark energy models.Concretely,the joint observation offersσ(w)=0.019 in the wCDM model,andσ(w0)=0.085 andσ(wa)=0.32 in the w0waCDM model.These results are better than or equal to those given by CMB+BAO+SN.In addition,when the foreground removal efficiency is relatively low,the strategy still performs well.Therefore,the 21 cm IM joint survey strategy is promising and worth pursuing.
基金supported by the Department of Science and Technology-Philippine Atmospheric,Geophysical,and Astronomical Services Administration(DOST-PAGASA)。
文摘This study introduces the‘Zero-Point Boundary’method to map the 2013 Typhoon Haiyan storm surge in coastal eastern Leyte.Utilising the‘Rivera Dispersive Wave Model’or RDM,we interpolated simulated storm surge and wave height data,subtracting them from a 5-m resolution digital terrain model raster provided by the National Mapping and Resource Information Authority(NAMRIA)to determine inundation limits and depths relative to the average Filipino male height(i.e.,165 cm).Validation against the 2013 joint survey conducted by the Japan Society of Civil Engineers(JSCE)and the Philippine Institute of Civil Engineers(PICE)showed an 81%accuracy rate when identifying water limit locations in Tacloban City,suggesting potential for future forecasting.However,the absence of compoundflooding consideration in the simulations may have influenced this rate.Overall,this study underscores the importance of accurate modelling and communication in hazard mapping for enhancing preparedness and mitigation efforts,emphasising a balanced approach to risk perception.
