Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercours...Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.展开更多
Radiant cooling system for thermal comfort of Thai people was developed. Questionnaires for subjective experiments were examined for development of radiant cooling system for thermal comfort. Thermal sensation, humid ...Radiant cooling system for thermal comfort of Thai people was developed. Questionnaires for subjective experiments were examined for development of radiant cooling system for thermal comfort. Thermal sensation, humid sensation and air movement sensation were used for thermal comfort assessment. The Predicted Mean Vote (PMV) value was used for thermal comfort evaluation and it was observed that the PMV values are in the comfortable ranges during 18:00 to 10:00 for air velocity 0.2 m/s and 0.4 m/s. Comfortable periods are extended for higher air velocity. Neutral temperatures are in the ranges of 26.44℃-33.60℃. The percentage number of dissatisfied (PPD) value for each air velocity was also investigate and the value of PPD is five for zero value of PMV. Simulation and experimental results were evaluated by using three indicators, namely, the coefficient of variation (CV), the mean bias error (MBE) and Chi-Square (x2). The values of CV, MBE and (x2) for mean radiant temperature are 14.52%, 1.54% and 3.95℃, respectively. Zones of acceptable thermal environment were developed for Thai People. Results revealed that the comfortable zones of Thai people are in the ranges of relative humidity 50% 70% and effective temperatures (ET) 24℃ 27℃.展开更多
在发生于2020年4月20日的地磁暴恢复相阶段,GOLD(Global-scale Observations of the Limb and Disk)成像仪在第112天(day of year,DOY 112)中低纬地区观测到氧原子(O)和氮气分子(N_(2))的柱密度比(ΣO/N_(2))的舌状中性结构(TON).TON结...在发生于2020年4月20日的地磁暴恢复相阶段,GOLD(Global-scale Observations of the Limb and Disk)成像仪在第112天(day of year,DOY 112)中低纬地区观测到氧原子(O)和氮气分子(N_(2))的柱密度比(ΣO/N_(2))的舌状中性结构(TON).TON结构一般指发生于中高纬且形成于两个ΣO/N_(2)暴时衰减结构之间的ΣO/N_(2)增强结构.热层-电离层电动力学大气环流模式(Thermosphere-Ionosphere-Electrodynamics General Circulation Model,TIEGCM)定性地模拟再现了在本次磁暴恢复相期间观测到的ΣO/N_(2)增强结构,并且发现这个结构在前一天(DOY 111)当地下午形成,通过中性风的输运被逐渐耗散.模拟结果呈现了不同高度O/N_(2)的TON结构的垂直变化,其强度和纬度范围有明显的高度依赖性,并且随磁暴演化不断变化.诊断分析表明:下沉流(downwelling)驱动的垂直输运首先导致较低纬(约30°N—70°N)O/N_(2)的增强,然后通过极向风驱动的水平输运将其向更高纬地区输运.在中低热层(约120~300 km高度),主导O/N_(2)的TON结构演化的中低纬极向风主要是由气压梯度力导致的,同时科里奥利力对极向风也有一定的正贡献.而在约300 km高度以上的高热层,极向风主要由气压梯度力和与其作用相反的垂直黏性力两项控制.展开更多
Thermogenic features are often invoked to illustrate animal’s colonization,distribution,and response to climate change.To understand why the White-browed Laughingthrush(Pterorhinus sannio)has expanded its distributio...Thermogenic features are often invoked to illustrate animal’s colonization,distribution,and response to climate change.To understand why the White-browed Laughingthrush(Pterorhinus sannio)has expanded its distribution to temperate zones in recent years,we compared its thermogenic features with three species of songbirds that cooccur in its newly colonized areas.Thermogenic parameters of these four species were measured under different ambient temperatures,ranging from 0 to 40℃.The results showed that basal metabolic rate(BMR)was 44.5±3.9 mL O2/h in P.sannio,which is lower than predicted value by its body weight.This is also lower than the BMR of both its temperate congener the Plain Laughingthrush(P.davidi)and the montane,similar species Elliot’s Laughingthrush(Trochalopteron elliotii).The thermal neutral zone(TNZ)in P.sannio was 15-35℃,as compared to 10-27.5℃in P.davidi,25-30℃in T.elliotii,and 7.5-32.5℃in the Green-capped Greenfinch(Chloris sinica).Thermal conductance was lowest in P.sannio,with the minimum value lower than the predicted value based on its body weight.Our results showed that the northward-colonizing P.sannio exhibited different thermogenic characteristics compared with its coexisting species in the new habitat,even its congener P.davidi,which shared similar microhabitats to P.sannio.We suggest that researchers further explore the physiological mechanisms of birds’northward expansion.展开更多
基金funded by Royalty and Price of the Mining Right of the Ministry of Finance and the Ministry of Land and Resources in 2012 ([2012]145)
文摘Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.
文摘Radiant cooling system for thermal comfort of Thai people was developed. Questionnaires for subjective experiments were examined for development of radiant cooling system for thermal comfort. Thermal sensation, humid sensation and air movement sensation were used for thermal comfort assessment. The Predicted Mean Vote (PMV) value was used for thermal comfort evaluation and it was observed that the PMV values are in the comfortable ranges during 18:00 to 10:00 for air velocity 0.2 m/s and 0.4 m/s. Comfortable periods are extended for higher air velocity. Neutral temperatures are in the ranges of 26.44℃-33.60℃. The percentage number of dissatisfied (PPD) value for each air velocity was also investigate and the value of PPD is five for zero value of PMV. Simulation and experimental results were evaluated by using three indicators, namely, the coefficient of variation (CV), the mean bias error (MBE) and Chi-Square (x2). The values of CV, MBE and (x2) for mean radiant temperature are 14.52%, 1.54% and 3.95℃, respectively. Zones of acceptable thermal environment were developed for Thai People. Results revealed that the comfortable zones of Thai people are in the ranges of relative humidity 50% 70% and effective temperatures (ET) 24℃ 27℃.
文摘在发生于2020年4月20日的地磁暴恢复相阶段,GOLD(Global-scale Observations of the Limb and Disk)成像仪在第112天(day of year,DOY 112)中低纬地区观测到氧原子(O)和氮气分子(N_(2))的柱密度比(ΣO/N_(2))的舌状中性结构(TON).TON结构一般指发生于中高纬且形成于两个ΣO/N_(2)暴时衰减结构之间的ΣO/N_(2)增强结构.热层-电离层电动力学大气环流模式(Thermosphere-Ionosphere-Electrodynamics General Circulation Model,TIEGCM)定性地模拟再现了在本次磁暴恢复相期间观测到的ΣO/N_(2)增强结构,并且发现这个结构在前一天(DOY 111)当地下午形成,通过中性风的输运被逐渐耗散.模拟结果呈现了不同高度O/N_(2)的TON结构的垂直变化,其强度和纬度范围有明显的高度依赖性,并且随磁暴演化不断变化.诊断分析表明:下沉流(downwelling)驱动的垂直输运首先导致较低纬(约30°N—70°N)O/N_(2)的增强,然后通过极向风驱动的水平输运将其向更高纬地区输运.在中低热层(约120~300 km高度),主导O/N_(2)的TON结构演化的中低纬极向风主要是由气压梯度力导致的,同时科里奥利力对极向风也有一定的正贡献.而在约300 km高度以上的高热层,极向风主要由气压梯度力和与其作用相反的垂直黏性力两项控制.
基金provided by the National Natural Science Foundation of China(Grant No.32070452,32011530077)。
文摘Thermogenic features are often invoked to illustrate animal’s colonization,distribution,and response to climate change.To understand why the White-browed Laughingthrush(Pterorhinus sannio)has expanded its distribution to temperate zones in recent years,we compared its thermogenic features with three species of songbirds that cooccur in its newly colonized areas.Thermogenic parameters of these four species were measured under different ambient temperatures,ranging from 0 to 40℃.The results showed that basal metabolic rate(BMR)was 44.5±3.9 mL O2/h in P.sannio,which is lower than predicted value by its body weight.This is also lower than the BMR of both its temperate congener the Plain Laughingthrush(P.davidi)and the montane,similar species Elliot’s Laughingthrush(Trochalopteron elliotii).The thermal neutral zone(TNZ)in P.sannio was 15-35℃,as compared to 10-27.5℃in P.davidi,25-30℃in T.elliotii,and 7.5-32.5℃in the Green-capped Greenfinch(Chloris sinica).Thermal conductance was lowest in P.sannio,with the minimum value lower than the predicted value based on its body weight.Our results showed that the northward-colonizing P.sannio exhibited different thermogenic characteristics compared with its coexisting species in the new habitat,even its congener P.davidi,which shared similar microhabitats to P.sannio.We suggest that researchers further explore the physiological mechanisms of birds’northward expansion.
