As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure...As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure the performance protection requirements.In order to clarify the rain erosion damage mechanism of radome coating and explore the influencing factors and mechanisms of coating material damage under different jet impact conditions,impact tests were conducted on three types of skin coating samples,and the damage mode was observed through electron microscopy characterization.The experimental results show that the typical morphology of rain erosion damage is annular surface peeling damage.The damage area and volume of the three coating samples increase with the continuous increase of raindrop impact velocity.The threshold velocity for initial damage to the coating is about 360 m/s;under the influence of the velocity component,the reduction in impact angle leads to a gradual reduction in the degree of damage to the sample.ABAQUS finite element simulation software was used to establish a constitutive model for coating rain erosion simulation and obtain the propagation law of stress waves during the impact process.The simulation results show that at the 75°impact angle,the jet impacts the surface of the specimen at different velocities,and as the impact velocity increases,the Mises equivalent stress on the surface shows an increasing trend,which is one of the main factors causing damage with increasing velocity.The effectiveness,rain erosion damage mode,and influencing mechanism of the model were verified based on the test results;the dynamic failure mechanism of the sample was further studied,and the stress propagation process at different impact angles was compared,revealing the influence mechanism and damage law of the impact angle on the high-speed raindrop impact of the material.展开更多
Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(...Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].展开更多
Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distri...Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.展开更多
This study employed a computational fluid dynamics model with an overset mesh technique to investigate the thrust and power of a floating offshore wind turbine(FOWT)under platform floating motion in the wind–rain fie...This study employed a computational fluid dynamics model with an overset mesh technique to investigate the thrust and power of a floating offshore wind turbine(FOWT)under platform floating motion in the wind–rain field.The impact of rainfall on aerodynamic performance was initially examined using a stationary turbine model in both wind and wind–rain conditions.Subsequently,the study compared the FOWT’s performance under various single degree-of-freedom(DOF)motions,including surge,pitch,heave,and yaw.Finally,the combined effects of wind–rain fields and platform motions involving two DOFs on the FOWT’s aerodynamics were analyzed and compared.The results demonstrate that rain negatively impacts the aerodynamic performance of both the stationary turbines and FOWTs.Pitch-dominated motions,whether involving single or multiple DOFs,caused significant fluctuations in the FOWT aerodynamics.The combination of surge and pitch motions created the most challenging operational environment for the FOWT in all tested scenarios.These findings highlighted the need for stronger construction materials and greater ultimate bearing capacity for FOWTs,as well as the importance of optimizing designs to mitigate excessive pitch and surge.展开更多
SNAPSHOTS OF CHINA Send us your photographs and let us know what lies behind them at contacts@chinafrica.cn Strolling in Rain Amid light rain and mist,tourists meander through the historic lanes of Chengkan Ancient Vi...SNAPSHOTS OF CHINA Send us your photographs and let us know what lies behind them at contacts@chinafrica.cn Strolling in Rain Amid light rain and mist,tourists meander through the historic lanes of Chengkan Ancient Village in Huangshan,Anhui Province.展开更多
Activity 1 Think about the following questions and write down your answers before reading the text.1.How do you think the rain in the Rain Report Caféwould affect people's mood when they are chatting with fri...Activity 1 Think about the following questions and write down your answers before reading the text.1.How do you think the rain in the Rain Report Caféwould affect people's mood when they are chatting with friends?Would it make them more relaxed or a bit distracted?2.How might the constant rain at Rain Report Caféaffect the mood of its customers?Activity 2 Read the text,and try to fill in the blank.The cafe has panoramic windows offering a clear view of its inner courtyard,_____.展开更多
A terrible disaster struck our town last month,which brought heavy rain and strong winds all night.Many houses were damaged,and some even fell down,leaving hundreds of people homeless.However,what surprised us most wa...A terrible disaster struck our town last month,which brought heavy rain and strong winds all night.Many houses were damaged,and some even fell down,leaving hundreds of people homeless.However,what surprised us most was the great unity shown by everyone.Neighbors helped each other carry things,sharing food and warm clothes,while volunteers from other towns came to offer support.With everyone's efforts,we started the recovery work quickly,which made us believe that we could rebuild our home soon.展开更多
Based on the data of daily precipitation in 11 national ground meteorological observation stations in Jining City from 1981 to 2020,the interdecadal variation,intensity,range and spatial distribution of rainstorms in ...Based on the data of daily precipitation in 11 national ground meteorological observation stations in Jining City from 1981 to 2020,the interdecadal variation,intensity,range and spatial distribution of rainstorms in Jining City were analyzed.The results show that the number of rainstorm days and the total amount of rainstorms in Jining City had significant changes among different decades.There was a continuous upward trend from the 1980s to the early 21 st century and a decrease after the early 21 st century.Rainstorms had distinct seasonal characteristics.They were mainly concentrated in summer,especially in July and August.In terms of spatial distribution,the frequency and intensity of rainstorms in the southeastern regions were significantly higher than those in the northwestern regions.The above results can provide a scientific basis for flood control and disaster reduction in Jining City.展开更多
This study addresses the limitations of traditional disaster medicine course assessments,including single evaluation formats,delayed feedback mechanisms,and gaps in competency mapping,by developing a diversified asses...This study addresses the limitations of traditional disaster medicine course assessments,including single evaluation formats,delayed feedback mechanisms,and gaps in competency mapping,by developing a diversified assessment system leveraging the Rain Classroom platform.The system incorporates six interconnected evaluation components across the learning cycle:pre-class preparation,pre-class tests,case discussions,skills assessment,post-class tests,and post-class feedback,collectively forming a three-dimensional“cognitive-skill-attitude”assessment framework.In the assessment design,the weighting of practical skill evaluation is elevated to 40%to prioritize the development of students’disaster response competencies.Additionally,an innovative multi-subject evaluation model(“self-peer-teacher”)is implemented within disaster scenario simulations,utilizing standardized scoring rubrics.This methodology not only enables comprehensive performance evaluation but also fosters critical teamwork and reflective practice.Implementation outcomes demonstrated that the system effectively evaluates learning progress through multi-modal assessments,enhances disaster rescue knowledge and skill proficiency,and successfully achieves predefined pedagogical objectives.展开更多
Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Cla...Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Classroom platform,we established a comprehensive intelligent teaching support system covering the entire learning cycle-pre-class,in-class,and post-class.Through AI-driven enhancements,the model enables intelligent resource allocation,personalized learning paths,and high-fidelity simulation of practical training scenarios.Moreover,it addresses key challenges in traditional disaster medicine education,including fragmented knowledge delivery,insufficient practical training environments,and limited evaluation methods.Ultimately,the model enhances both the efficiency and effectiveness of disaster medicine education.展开更多
1.Because it’s a maths problem about rain!因为这是一道关于下雨的数学题Mom:Why is your homework wet?Child:Because it’s a maths problem about rain!妈妈:为什么你的家庭作业湿了?孩子:因为这是一道关于下雨的数学题。
In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs bro...In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs brought large-scale heavy rainfall to North China,with daily precipitation exceeding 100 mm.Using reanalysis datasets and gridded precipitation data,the ETCs that affected Central and Eastern China during the boreal midsummer from 1981 to 2020 were objectively identified and tracked.ETCs causing precipitation were classified based on maximum daily precipitation,resulting in datasets for ETCs with torrential rain(daily precipitation exceeding 100 mm,referred to as ETC_R100)and heavy rain(daily precipitation exceeding 25 mm,referred to as ETC_R25).Comparative analysis can help highlight the characteristics of ETC_R100.This study compares the spatial distribution,movement paths,weather impacts,large-scale atmospheric circulation,and environmental conditions of these two types of precipitation-related ETCs.The following findings emerged:(1)ETC_R100 is driven by the combined forcing of upper-level troughs and warm-moist airflows at lower levels,exhibiting stronger thermal forcing than ETC_R25.(2)The moisture source for ETC_R100 are the Bay of Bengal and the Northwest Pacific,with moisture transported via the South China Sea.Compared to ETCs with nonextreme rainfall,ETC_R100 is characterized by greater atmospheric instability and better moisture conditions,resulting in higher precipitation intensity.(3)Regardless of the precipitation level,ETCs affected different regions but contributed significantly to precipitation in northern China,accounting for approximately 50%of the total precipitation.The results indicate that ETC_R100 differs significantly from ETCs with varying levels of precipitation in terms of statistical characteristics,weather impact,environmental conditions,and cyclogenesis conditions.展开更多
Dengue fever presents a significant and persistent public health challenge in Sri Lanka.The disease,transmitted by Aedes aegypti and Aedes albopictus mosquitoes,affects individuals across all age groups,with working p...Dengue fever presents a significant and persistent public health challenge in Sri Lanka.The disease,transmitted by Aedes aegypti and Aedes albopictus mosquitoes,affects individuals across all age groups,with working populations and school-aged children at higher risk due to increased outdoor exposure[1].Dengue transmission in Sri Lanka is seasonal with two high transmission waves corresponding with the two monsoon rains every year.The estimated average annual incidence is 175/100000 population,and it was 407.5/100000 in 2023 with a case fatality rate of 0.07%[2].展开更多
A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Hena...A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Henan Province,China,on 20 July 2021.The simulation results showed that a strong meso-𝛾-scale vortical updraft was concurrent with the torrential rainfall.The main finding is that this event was characterized by typical midlatitude warm-rain processes.The simulation with the Thompson microphysics scheme further indicated that highly efficient collision-coalescence of cloud water to rainwater resulted in a considerably active rain droplet growth,leading to this record-breaking rainfall event.展开更多
Editor's Note:Sixty years of nurturing winds and rains,sixty years of protound change.This year marks the 60th anniversary of the founding of the Xizang Autonomous Region.To mark this important historical mileston...Editor's Note:Sixty years of nurturing winds and rains,sixty years of protound change.This year marks the 60th anniversary of the founding of the Xizang Autonomous Region.To mark this important historical milestone,this column presents frontline reports and observations by our journalists.展开更多
In research on the legendary Xia Dynasty of ancient China,the famous archaeological site of Erlitou and its culture are the most debated topics.A key question is whether this ancient culture is truly related to the Xi...In research on the legendary Xia Dynasty of ancient China,the famous archaeological site of Erlitou and its culture are the most debated topics.A key question is whether this ancient culture is truly related to the Xia Dynasty.This study combines traditional literature(Xia Xiao Zheng),archaeological evidence(on alligators),and climate simulation(of autumn rains)to demonstrate that the ancient Chinese phenological calendar,Xia Xiao Zheng,likely originated in the same region as the Erlitou culture.A logical explanation of these findings is that both Xia Xiao Zheng and the Erlitou culture are indeed closely related to the Xia Dynasty.展开更多
在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,...在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,它的诞生糅合了神话想象与历史现实,成为英语文化中一道独特的语言风景。展开更多
The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base sol...The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12261131505,U2241274)the Russian Science Fund(No.23-49-00133)+3 种基金the Aeronautical Science Foundation of China(No.20240002053002)the Natural Science Basic Research Program of Shaanxi,China(No.2025JC-YBMS-005)the Key Research and Development Program of Shaanxi,China(No.2024GX-YBXM-037)the Basic Research Programs of Taicang,China(No.TC2024JC10)。
文摘As the main component of the aircraft leading edge,the radome is often the first to be hit by raindrops and cause structural damage when passing through a rain field.Rain resistant coating is usually applied to ensure the performance protection requirements.In order to clarify the rain erosion damage mechanism of radome coating and explore the influencing factors and mechanisms of coating material damage under different jet impact conditions,impact tests were conducted on three types of skin coating samples,and the damage mode was observed through electron microscopy characterization.The experimental results show that the typical morphology of rain erosion damage is annular surface peeling damage.The damage area and volume of the three coating samples increase with the continuous increase of raindrop impact velocity.The threshold velocity for initial damage to the coating is about 360 m/s;under the influence of the velocity component,the reduction in impact angle leads to a gradual reduction in the degree of damage to the sample.ABAQUS finite element simulation software was used to establish a constitutive model for coating rain erosion simulation and obtain the propagation law of stress waves during the impact process.The simulation results show that at the 75°impact angle,the jet impacts the surface of the specimen at different velocities,and as the impact velocity increases,the Mises equivalent stress on the surface shows an increasing trend,which is one of the main factors causing damage with increasing velocity.The effectiveness,rain erosion damage mode,and influencing mechanism of the model were verified based on the test results;the dynamic failure mechanism of the sample was further studied,and the stress propagation process at different impact angles was compared,revealing the influence mechanism and damage law of the impact angle on the high-speed raindrop impact of the material.
文摘Climate model prediction has been improved by enhancing model resolution as well as the implementation of sophisticated physical parameterization and refinement of data assimilation systems[section 6.1 in Wang et al.(2025)].In relation to seasonal forecasting and climate projection in the East Asian summer monsoon season,proper simulation of the seasonal migration of rain bands by models is a challenging and limiting factor[section 7.1 in Wang et al.(2025)].
基金funded by the National Natural Science Foundation of China(Grant No.42325503)the Hubei Provincial Natural Science Foundation and the Meteorological Innovation and Development Project of China(Grant Nos.2023AFD096 and 2022CFD122)+1 种基金the Natural Science Foundation of Wuhan(Grant No.2024020901030454)the Beijige Foundation of NJIAS(Grant No.BJG202304)。
文摘Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.
基金Supported by the National Natural Science Foundation of China(51679080 and 51379073)the Fundamental Research Funds for the Central Universities(B230205020).
文摘This study employed a computational fluid dynamics model with an overset mesh technique to investigate the thrust and power of a floating offshore wind turbine(FOWT)under platform floating motion in the wind–rain field.The impact of rainfall on aerodynamic performance was initially examined using a stationary turbine model in both wind and wind–rain conditions.Subsequently,the study compared the FOWT’s performance under various single degree-of-freedom(DOF)motions,including surge,pitch,heave,and yaw.Finally,the combined effects of wind–rain fields and platform motions involving two DOFs on the FOWT’s aerodynamics were analyzed and compared.The results demonstrate that rain negatively impacts the aerodynamic performance of both the stationary turbines and FOWTs.Pitch-dominated motions,whether involving single or multiple DOFs,caused significant fluctuations in the FOWT aerodynamics.The combination of surge and pitch motions created the most challenging operational environment for the FOWT in all tested scenarios.These findings highlighted the need for stronger construction materials and greater ultimate bearing capacity for FOWTs,as well as the importance of optimizing designs to mitigate excessive pitch and surge.
文摘SNAPSHOTS OF CHINA Send us your photographs and let us know what lies behind them at contacts@chinafrica.cn Strolling in Rain Amid light rain and mist,tourists meander through the historic lanes of Chengkan Ancient Village in Huangshan,Anhui Province.
文摘Activity 1 Think about the following questions and write down your answers before reading the text.1.How do you think the rain in the Rain Report Caféwould affect people's mood when they are chatting with friends?Would it make them more relaxed or a bit distracted?2.How might the constant rain at Rain Report Caféaffect the mood of its customers?Activity 2 Read the text,and try to fill in the blank.The cafe has panoramic windows offering a clear view of its inner courtyard,_____.
文摘A terrible disaster struck our town last month,which brought heavy rain and strong winds all night.Many houses were damaged,and some even fell down,leaving hundreds of people homeless.However,what surprised us most was the great unity shown by everyone.Neighbors helped each other carry things,sharing food and warm clothes,while volunteers from other towns came to offer support.With everyone's efforts,we started the recovery work quickly,which made us believe that we could rebuild our home soon.
基金the Project of Jining Meteorological Bureau(2023JNZL09).
文摘Based on the data of daily precipitation in 11 national ground meteorological observation stations in Jining City from 1981 to 2020,the interdecadal variation,intensity,range and spatial distribution of rainstorms in Jining City were analyzed.The results show that the number of rainstorm days and the total amount of rainstorms in Jining City had significant changes among different decades.There was a continuous upward trend from the 1980s to the early 21 st century and a decrease after the early 21 st century.Rainstorms had distinct seasonal characteristics.They were mainly concentrated in summer,especially in July and August.In terms of spatial distribution,the frequency and intensity of rainstorms in the southeastern regions were significantly higher than those in the northwestern regions.The above results can provide a scientific basis for flood control and disaster reduction in Jining City.
基金supported by the Anesthesiology Department Teaching Development Foundation of Naval Medical University under grant(2024MZQN02 and 2024MZQN03).
文摘This study addresses the limitations of traditional disaster medicine course assessments,including single evaluation formats,delayed feedback mechanisms,and gaps in competency mapping,by developing a diversified assessment system leveraging the Rain Classroom platform.The system incorporates six interconnected evaluation components across the learning cycle:pre-class preparation,pre-class tests,case discussions,skills assessment,post-class tests,and post-class feedback,collectively forming a three-dimensional“cognitive-skill-attitude”assessment framework.In the assessment design,the weighting of practical skill evaluation is elevated to 40%to prioritize the development of students’disaster response competencies.Additionally,an innovative multi-subject evaluation model(“self-peer-teacher”)is implemented within disaster scenario simulations,utilizing standardized scoring rubrics.This methodology not only enables comprehensive performance evaluation but also fosters critical teamwork and reflective practice.Implementation outcomes demonstrated that the system effectively evaluates learning progress through multi-modal assessments,enhances disaster rescue knowledge and skill proficiency,and successfully achieves predefined pedagogical objectives.
基金supported by the Anesthesiology Department Teaching Development Foundation of Naval Medical University(2024MZQN03)the Teaching Research and Reform Project of Naval Medical University(JYG2024B24).
文摘Artificial Intelligence is profoundly transforming innovation and development in healthcare and education.In this study,we developed an AI-empowered blended learning model for disaster medicine.Leveraging the Rain Classroom platform,we established a comprehensive intelligent teaching support system covering the entire learning cycle-pre-class,in-class,and post-class.Through AI-driven enhancements,the model enables intelligent resource allocation,personalized learning paths,and high-fidelity simulation of practical training scenarios.Moreover,it addresses key challenges in traditional disaster medicine education,including fragmented knowledge delivery,insufficient practical training environments,and limited evaluation methods.Ultimately,the model enhances both the efficiency and effectiveness of disaster medicine education.
文摘1.Because it’s a maths problem about rain!因为这是一道关于下雨的数学题Mom:Why is your homework wet?Child:Because it’s a maths problem about rain!妈妈:为什么你的家庭作业湿了?孩子:因为这是一道关于下雨的数学题。
基金National Natural Science Foundation of China(42375014,42088101,42030605)Joint Research Project for Meteorological Capacity Improvement(24NLTSZ010)Young Elite Scientists Sponsorship Program by BAST(BYESS2023205)。
文摘In recent years,torrential rain events caused by extratropical cyclones(ETCs)during the boreal midsummer(July-August)in Central and Eastern China have shown an increasing trend.For instence,in August 2024,two ETCs brought large-scale heavy rainfall to North China,with daily precipitation exceeding 100 mm.Using reanalysis datasets and gridded precipitation data,the ETCs that affected Central and Eastern China during the boreal midsummer from 1981 to 2020 were objectively identified and tracked.ETCs causing precipitation were classified based on maximum daily precipitation,resulting in datasets for ETCs with torrential rain(daily precipitation exceeding 100 mm,referred to as ETC_R100)and heavy rain(daily precipitation exceeding 25 mm,referred to as ETC_R25).Comparative analysis can help highlight the characteristics of ETC_R100.This study compares the spatial distribution,movement paths,weather impacts,large-scale atmospheric circulation,and environmental conditions of these two types of precipitation-related ETCs.The following findings emerged:(1)ETC_R100 is driven by the combined forcing of upper-level troughs and warm-moist airflows at lower levels,exhibiting stronger thermal forcing than ETC_R25.(2)The moisture source for ETC_R100 are the Bay of Bengal and the Northwest Pacific,with moisture transported via the South China Sea.Compared to ETCs with nonextreme rainfall,ETC_R100 is characterized by greater atmospheric instability and better moisture conditions,resulting in higher precipitation intensity.(3)Regardless of the precipitation level,ETCs affected different regions but contributed significantly to precipitation in northern China,accounting for approximately 50%of the total precipitation.The results indicate that ETC_R100 differs significantly from ETCs with varying levels of precipitation in terms of statistical characteristics,weather impact,environmental conditions,and cyclogenesis conditions.
文摘Dengue fever presents a significant and persistent public health challenge in Sri Lanka.The disease,transmitted by Aedes aegypti and Aedes albopictus mosquitoes,affects individuals across all age groups,with working populations and school-aged children at higher risk due to increased outdoor exposure[1].Dengue transmission in Sri Lanka is seasonal with two high transmission waves corresponding with the two monsoon rains every year.The estimated average annual incidence is 175/100000 population,and it was 407.5/100000 in 2023 with a case fatality rate of 0.07%[2].
基金jointly supported by the National Natural Science Foundation of China[grant numbers U2342202 and 42175005]the Qing Lan Project[grant number R2023Q06]。
文摘A numerical simulation was performed using the Thompson microphysics scheme to preliminarily investigate the features of the microphysical processes involved in the record-breaking rainfall event that occurred in Henan Province,China,on 20 July 2021.The simulation results showed that a strong meso-𝛾-scale vortical updraft was concurrent with the torrential rainfall.The main finding is that this event was characterized by typical midlatitude warm-rain processes.The simulation with the Thompson microphysics scheme further indicated that highly efficient collision-coalescence of cloud water to rainwater resulted in a considerably active rain droplet growth,leading to this record-breaking rainfall event.
文摘Editor's Note:Sixty years of nurturing winds and rains,sixty years of protound change.This year marks the 60th anniversary of the founding of the Xizang Autonomous Region.To mark this important historical milestone,this column presents frontline reports and observations by our journalists.
基金National Key Research and Development Program of China,No.2023YFF0804704National Natural Science Foundation of China,No.42130604,No.42105044+1 种基金Major Projects of the Ministry of Education's Key Research Bases of Humanities and Social Sciences,No.22JJD770020Social Scienceof Northwest University,No.21XNFH007。
文摘In research on the legendary Xia Dynasty of ancient China,the famous archaeological site of Erlitou and its culture are the most debated topics.A key question is whether this ancient culture is truly related to the Xia Dynasty.This study combines traditional literature(Xia Xiao Zheng),archaeological evidence(on alligators),and climate simulation(of autumn rains)to demonstrate that the ancient Chinese phenological calendar,Xia Xiao Zheng,likely originated in the same region as the Erlitou culture.A logical explanation of these findings is that both Xia Xiao Zheng and the Erlitou culture are indeed closely related to the Xia Dynasty.
文摘在英语影视剧或文学作品中,你或许见过这样的场景:主角望着窗外倾盆大雨惊呼“It’s raining cats and dogs!”。其中,raining cats and dogs字面意思是“天上掉猫狗”,实际却用来形容暴雨如瀑布般猛烈。这种超现实的表达并非空穴来风,它的诞生糅合了神话想象与历史现实,成为英语文化中一道独特的语言风景。
文摘The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.
