On October 24,the opening ceremony of the MercedesBenz China Fashion Week was held in Beijing’s China Central Place.The Chinese Textile Industry Association,the China Fashion Association,the Beijing Textile Industry ...On October 24,the opening ceremony of the MercedesBenz China Fashion Week was held in Beijing’s China Central Place.The Chinese Textile Industry Association,the China Fashion Association,the Beijing Textile Industry Association and other relevant leaders attended the ceremony,and the Italian National Fashion Association honorary Chairman,European Design Center honorary president Mr.展开更多
The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,...The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,this study finds that the relationship between El Nino-Southern Oscillation(ENSO)and monsoon commencement experiences a notable interdecadal strengthening after 1976/77.While the response of tropical tropospheric temperature to ENSO remains largely unchanged,ENSO induces a stronger Walker circulation,a more pronounced equatorial Rossby wave,and an intensified extratropical Rossby wave train after 1976/77.These enhanced atmospheric processes,which directly reinforce the ENSO-TASM commencement relationship,are likely driven by interdecadal shifts in the structure and variance of ENSO.Post-1976/77,ENSO displays increased variance and a more coherent structure,with more pronounced sea surface temperature anomalies in the western North Pacific and subtropical North Pacific.Given the limitations of observational data,a 1000-year piControl experiment further confirms the role of ENSO variance changes in strengthening its influence on monsoon commencement.Our findings underscore the critical influence of evolving ENSO characteristics on climate anomalies such as monsoon commencement,offering potential insights for short-term climate prediction.展开更多
Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear....Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear.This study explores the interannual variations in summer MP-EHEs and their relationship with the summer soil moisture over the Inner Tibetan Plateau(TP-SM).The results reveal that changes in the MP-EHEs are linked to descending atmospheric motion induced by a local high-pressure system over the MP region.Descending motion further results in decreased mid-tolow-level cloud cover and increased shortwave radiation,thereby warming the surface and triggering summer MP-EHEs.Further analysis indicates that increased TP-SM results in a greater latent heat flux,triggering a local secondary circulation that reinforces the local high-pressure system over the MP region,thus serving to promote the occurrence of summer MPEHEs.Additionally,model results from the linear baroclinic model(LBM)and CMIP6 further confirm that variations in summer TP-SM contribute to the occurrence of the MP-EHEs.展开更多
Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the i...Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the impacts of wildfire on hydrology have been widely assessed at the watershed scale,the underlying mechanisms of the responses of summer low flows remain poorly understood.In this study,we employed an integrated research framework that combines hydrometric monitoring with geochemical tracing to evaluate how the 2021 White Rock Lake Wildfire affected summer low flows,and to identify the underlying mechanisms governing these responses in the Okanagan Valley,British Columbia(BC),Canada.We found that(1)summer low flows,represented by Q90(flows exceeded at 90%of the time in summer)significantly increased following the wildfire(p<0.05);(2)summer low flows were primarily regulated by snow water in early summer(July),while dominated by groundwater in late summer(August and September);and(3)enhanced snow water contribution and reduced evapotranspiration(ET)were two primary contributors to the increased summer low flows.Our results provide insights for developing sustainable water management strategies for the region in the context of climate change and increasing forest disturbance.This study also demonstrates that the combination of hydrometric monitoring and geochemical tracing is an effective approach towards uncovering mechanisms that drive low-flow responses.展开更多
The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new con...The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.展开更多
Based on reanalysis data from 1979 to 2021,this study explores the spatial distribution of the Southern Indian Ocean Dipole(SIOD)and its individual and synergistic effects with the El Niño-Southern Oscillation(EN...Based on reanalysis data from 1979 to 2021,this study explores the spatial distribution of the Southern Indian Ocean Dipole(SIOD)and its individual and synergistic effects with the El Niño-Southern Oscillation(ENSO)on summer precipitation in China.The inverse phase spatial distribution of sea surface temperature anomalies(SSTAs)in the southwest and northeast of the southern Indian Ocean is defined as the SIOD.Positive SIOD events(positive SSTAs in the southwest,negative SSTAs in the northeast)are associated with La Niña events(Central Pacific(CP)type),while negative SIOD events(negative SSTAs in the southwest,positive SSTAs in the northeast)are associated with El Niño events(Eastern Pacific(EP)type).Both SIOD and ENSO have certain impacts on summer precipitation in China.Precipitation in the Yangtze River basin decreases,while precipitation in southern China increases during pure positive SIOD(P_PSIOD)events.During pure negative SIOD(P_NSIOD)events,the changes in precipitation are exactly the opposite of those during P_PSIOD events,which may be due to differences in the cross-equatorial flow in the southern Indian Ocean,particularly in low-level Australian cross-equatorial flow.When positive SIOD and CP-type La Niña events occur simultaneously(PSIOD+La_Niña),precipitation increases in the Yangtze-Huaihe River basin,while it decreases in northern China.When negative SIOD and EP-type El Niño events occur simultaneously(NSIOD+El_Niño),precipitation in the Yangtze-Huaihe River basin is significantly lower than during P_NSIOD events.This is caused by differences in water vapor originating from the Pacific Ocean during different events.展开更多
This study investigated the impacts of key parameters in CAM6's deep convection and cloud physics schemes on the simulation of summer-mean precipitation over East Asia through conducting perturbed parameter ensemb...This study investigated the impacts of key parameters in CAM6's deep convection and cloud physics schemes on the simulation of summer-mean precipitation over East Asia through conducting perturbed parameter ensemble(PPE)experiments.Utilizing the experimental platform of CAM6,a suite of 128 PPE simulations spanning 19792014 were generated through simultaneously perturbing 12 selected parameters.Using EOF analysis,this study firstly extracted the first two leading modes of the precipitation simulation biases.The authors further pinpointed the most critical parameters that have the most influential effects on the precipitation simulation biases,through conducting generalized linear model analysis.The first leading mode of precipitation simulation biases is primarily influenced by parameters from the cloud physics scheme,including the linear effects of dcs and eii,and the nonlinear effect of rhminl*dcs.These parameters influence the simulated total precipitation(PrecT)mainly by altering the large-scale precipitation(PrecL).The second leading mode is predominantly governed by the convection scheme parameter dmpdz,reflecting a competition between the changes in convective precipitation(PrecC)and PrecL in response to variations in dmpdz.An increase in dmpdz induces decreased PrecC and increased PrecL in East Asia,and both of the changes collectively shape the ultimate PrecT response to the adjusted dmpdz.Lastly,it is noteworthy that the nonlinear effect due to the interaction among parameters warrants attention when concurrently adjusting multiple parameters,and the precipitation biases from the PPE simulations resemble those identified through EOF analysis on the AMIP simulations,implying our findings may provide potential reference for other AGCMs.展开更多
The electrode structures in ignition devices for Electrically Controlled Solid Propellants(ECSP) can be classified into fixed and movable types. In movable electrode structures, springs are typically used to push the ...The electrode structures in ignition devices for Electrically Controlled Solid Propellants(ECSP) can be classified into fixed and movable types. In movable electrode structures, springs are typically used to push the electrodes and the propellant. The effects of spring pressure on the ignition and combustion of propellants have not yet been studied. In this paper, a universal testing machine and an electrochemical workstation were firstly utilized to investigate the compressive mechanical property and conductivity of Hydroxylamine Nitrate(HAN)-ECSP. The maximum pressure at which the propellant undergoes elastic deformation is 65 kPa. When the spring pressure increased from 5.1 k Pa to 20.4 kPa, the propellant resistance decreased from 56.8 Ω to 36.8 Ω.Various observation methods were employed to study the process of electrical energy injection and the ignition and combustion characteristics under constant voltage. Appropriately increasing the spring pressure can accelerate the injection of electrical energy into the propellant, increase the electrification current, and thus reduce the initial ignition delay time of the propellant. When the spring pressure is 20.4 kPa, the squeezing speed of the propellant is too fast, making it difficult for the propellant to be adequately heated at the electrode interface, which is unfavorable for ignition. Excessive spring pressure also leads to the accumulation of a large amount of combustion residue on the electrode plate, hindering the mixing and diffusion of hot gases during the second ignition process, preventing the gaseous flame of the propellant. When the spring pressure is 5.1 kPa, improving the working voltage can enhance the repeated ignition characteristics of the propellant.展开更多
文摘On October 24,the opening ceremony of the MercedesBenz China Fashion Week was held in Beijing’s China Central Place.The Chinese Textile Industry Association,the China Fashion Association,the Beijing Textile Industry Association and other relevant leaders attended the ceremony,and the Italian National Fashion Association honorary Chairman,European Design Center honorary president Mr.
基金supported jointly by the Natural Science Foundation of Yunnan Province(Grant No.202501CF070059)the National Natural Science Foundation of China(Grant No.42205021)+5 种基金the Yunnan Provincial Science and Technology Department(Grant Nos.202505AB350001 and202403AP140009)the Yunnan Southwest United Graduate School Science and Technology Special Project(Award No.202302AP370003)the Scientific Research Fund Project of Yunnan Education Department(Grant No.2025Y0111)the Practical Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University(Grant No.KC-24248868)the Practical Innovation Project of Postgraduate Students in the Professional Degree of Yunnan University(Grant No.ZC-24248604)the Youth Science and Technology Fund Project of Gansu Province(Grant No.24JRRA1186)。
文摘The commencement of the tropical Asian summer monsoon(TASM)in May is a crucial phase in its seasonal evolution,with critical implications for agriculture and water resources.Based on observational and reanalysis data,this study finds that the relationship between El Nino-Southern Oscillation(ENSO)and monsoon commencement experiences a notable interdecadal strengthening after 1976/77.While the response of tropical tropospheric temperature to ENSO remains largely unchanged,ENSO induces a stronger Walker circulation,a more pronounced equatorial Rossby wave,and an intensified extratropical Rossby wave train after 1976/77.These enhanced atmospheric processes,which directly reinforce the ENSO-TASM commencement relationship,are likely driven by interdecadal shifts in the structure and variance of ENSO.Post-1976/77,ENSO displays increased variance and a more coherent structure,with more pronounced sea surface temperature anomalies in the western North Pacific and subtropical North Pacific.Given the limitations of observational data,a 1000-year piControl experiment further confirms the role of ENSO variance changes in strengthening its influence on monsoon commencement.Our findings underscore the critical influence of evolving ENSO characteristics on climate anomalies such as monsoon commencement,offering potential insights for short-term climate prediction.
基金supported by the National Natural Science Foundation of China(Grant No.42288101)the Young Scientists Fund of the National Natural Science Foundation of China(Grand No.42505018)the Shanghai“Science and Technology Innovation Action Plan”Venus Project(Grant No.23YF1437300)。
文摘Recent studies have suggested that rapid warming over the Mongolian Plateau(MP)may intensify extreme heat events(EHEs).However,the characteristics and mechanisms driving summer EHEs over the MP(MP-EHEs)remain unclear.This study explores the interannual variations in summer MP-EHEs and their relationship with the summer soil moisture over the Inner Tibetan Plateau(TP-SM).The results reveal that changes in the MP-EHEs are linked to descending atmospheric motion induced by a local high-pressure system over the MP region.Descending motion further results in decreased mid-tolow-level cloud cover and increased shortwave radiation,thereby warming the surface and triggering summer MP-EHEs.Further analysis indicates that increased TP-SM results in a greater latent heat flux,triggering a local secondary circulation that reinforces the local high-pressure system over the MP region,thus serving to promote the occurrence of summer MPEHEs.Additionally,model results from the linear baroclinic model(LBM)and CMIP6 further confirm that variations in summer TP-SM contribute to the occurrence of the MP-EHEs.
基金the China Scholarship Council(CSC)the Uplifting Reciprocal Research Scholarship Program for sponsoring Shixuan Lyu+1 种基金supported by MITACS Accelerate(No.IT39116)the Okanagan Basin Water Board water conservation and quality improvement grant program。
文摘Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the impacts of wildfire on hydrology have been widely assessed at the watershed scale,the underlying mechanisms of the responses of summer low flows remain poorly understood.In this study,we employed an integrated research framework that combines hydrometric monitoring with geochemical tracing to evaluate how the 2021 White Rock Lake Wildfire affected summer low flows,and to identify the underlying mechanisms governing these responses in the Okanagan Valley,British Columbia(BC),Canada.We found that(1)summer low flows,represented by Q90(flows exceeded at 90%of the time in summer)significantly increased following the wildfire(p<0.05);(2)summer low flows were primarily regulated by snow water in early summer(July),while dominated by groundwater in late summer(August and September);and(3)enhanced snow water contribution and reduced evapotranspiration(ET)were two primary contributors to the increased summer low flows.Our results provide insights for developing sustainable water management strategies for the region in the context of climate change and increasing forest disturbance.This study also demonstrates that the combination of hydrometric monitoring and geochemical tracing is an effective approach towards uncovering mechanisms that drive low-flow responses.
基金supported by the National Natural Science Foundation of China(U2243235)the Shaanxi Provincial Department of Water Resources,China(2022slkj-6)。
文摘The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.
基金supported by the National Natural Science Foundation of China[grant numbers 41975087,U2242212,and 41975085]supported by the National Natural Science Foundation of China[grant number U2242212]。
文摘Based on reanalysis data from 1979 to 2021,this study explores the spatial distribution of the Southern Indian Ocean Dipole(SIOD)and its individual and synergistic effects with the El Niño-Southern Oscillation(ENSO)on summer precipitation in China.The inverse phase spatial distribution of sea surface temperature anomalies(SSTAs)in the southwest and northeast of the southern Indian Ocean is defined as the SIOD.Positive SIOD events(positive SSTAs in the southwest,negative SSTAs in the northeast)are associated with La Niña events(Central Pacific(CP)type),while negative SIOD events(negative SSTAs in the southwest,positive SSTAs in the northeast)are associated with El Niño events(Eastern Pacific(EP)type).Both SIOD and ENSO have certain impacts on summer precipitation in China.Precipitation in the Yangtze River basin decreases,while precipitation in southern China increases during pure positive SIOD(P_PSIOD)events.During pure negative SIOD(P_NSIOD)events,the changes in precipitation are exactly the opposite of those during P_PSIOD events,which may be due to differences in the cross-equatorial flow in the southern Indian Ocean,particularly in low-level Australian cross-equatorial flow.When positive SIOD and CP-type La Niña events occur simultaneously(PSIOD+La_Niña),precipitation increases in the Yangtze-Huaihe River basin,while it decreases in northern China.When negative SIOD and EP-type El Niño events occur simultaneously(NSIOD+El_Niño),precipitation in the Yangtze-Huaihe River basin is significantly lower than during P_NSIOD events.This is caused by differences in water vapor originating from the Pacific Ocean during different events.
基金jointly supported by the National Key Research and Development Program of China [grant number 2022YFF0802004]the Excellent Youth Natural Science Foundation of Jiangsu Province [grant number BK20230061]the Joint Open Project of KLME&CIC-FEMD[grant number KLME202501]。
文摘This study investigated the impacts of key parameters in CAM6's deep convection and cloud physics schemes on the simulation of summer-mean precipitation over East Asia through conducting perturbed parameter ensemble(PPE)experiments.Utilizing the experimental platform of CAM6,a suite of 128 PPE simulations spanning 19792014 were generated through simultaneously perturbing 12 selected parameters.Using EOF analysis,this study firstly extracted the first two leading modes of the precipitation simulation biases.The authors further pinpointed the most critical parameters that have the most influential effects on the precipitation simulation biases,through conducting generalized linear model analysis.The first leading mode of precipitation simulation biases is primarily influenced by parameters from the cloud physics scheme,including the linear effects of dcs and eii,and the nonlinear effect of rhminl*dcs.These parameters influence the simulated total precipitation(PrecT)mainly by altering the large-scale precipitation(PrecL).The second leading mode is predominantly governed by the convection scheme parameter dmpdz,reflecting a competition between the changes in convective precipitation(PrecC)and PrecL in response to variations in dmpdz.An increase in dmpdz induces decreased PrecC and increased PrecL in East Asia,and both of the changes collectively shape the ultimate PrecT response to the adjusted dmpdz.Lastly,it is noteworthy that the nonlinear effect due to the interaction among parameters warrants attention when concurrently adjusting multiple parameters,and the precipitation biases from the PPE simulations resemble those identified through EOF analysis on the AMIP simulations,implying our findings may provide potential reference for other AGCMs.
基金supported by the National Natural Science Foundation of China(Nos.T222100,22205258,52302485 and 2024JJ5404).
文摘The electrode structures in ignition devices for Electrically Controlled Solid Propellants(ECSP) can be classified into fixed and movable types. In movable electrode structures, springs are typically used to push the electrodes and the propellant. The effects of spring pressure on the ignition and combustion of propellants have not yet been studied. In this paper, a universal testing machine and an electrochemical workstation were firstly utilized to investigate the compressive mechanical property and conductivity of Hydroxylamine Nitrate(HAN)-ECSP. The maximum pressure at which the propellant undergoes elastic deformation is 65 kPa. When the spring pressure increased from 5.1 k Pa to 20.4 kPa, the propellant resistance decreased from 56.8 Ω to 36.8 Ω.Various observation methods were employed to study the process of electrical energy injection and the ignition and combustion characteristics under constant voltage. Appropriately increasing the spring pressure can accelerate the injection of electrical energy into the propellant, increase the electrification current, and thus reduce the initial ignition delay time of the propellant. When the spring pressure is 20.4 kPa, the squeezing speed of the propellant is too fast, making it difficult for the propellant to be adequately heated at the electrode interface, which is unfavorable for ignition. Excessive spring pressure also leads to the accumulation of a large amount of combustion residue on the electrode plate, hindering the mixing and diffusion of hot gases during the second ignition process, preventing the gaseous flame of the propellant. When the spring pressure is 5.1 kPa, improving the working voltage can enhance the repeated ignition characteristics of the propellant.
