By using the TRMM and QuikSCAT datathe characteristics of the 2–8 day high frequency atmospheric variability over the South China Sea are studied in this paper.It’s found that： （1） the 2–8 day high frequency sig...By using the TRMM and QuikSCAT datathe characteristics of the 2–8 day high frequency atmospheric variability over the South China Sea are studied in this paper.It’s found that： （1） the 2–8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon （SCSSM）,but also after the retreat of the SCSSM.It reaches its peak around July to August;（2） the 2–8 day high frequency signals exhibit strong intermittent features;（3） During El Nino years,the 2–8 day high frequency signals are active only in the periods of the SCSSM.During La Nina years,the 2–8 day high frequency signals are obviously not only in periods of the SCSSM,but also after the retreat of the SCSSM.During the SCSSM periods,the 2–8 day high frequency signals in El Nino years are much stronger than that in La Nina years;（4） During spring to early summer,most of 2–8 day signals propagate southward and eastward,during midsummer to autumn,however,most of 2–8-day signals propagate northward and westward;（5） The 2–8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS.展开更多
The three-dimensional structures of summer precipitation over the South China Sea （SCS） and the East China Sea （ECS） are investigated based on tropical rainfall measurement mission （TRMM）. The primary results ar...The three-dimensional structures of summer precipitation over the South China Sea （SCS） and the East China Sea （ECS） are investigated based on tropical rainfall measurement mission （TRMM）. The primary results are as follows. First, both the convective and stratiform precipitation rates in the SCS are much higher than those of the ECS. The contribution of the convective cloud precipitation to the surface precipitation is primarily over the SCS and the ECS with a proportion of about 70%, but the contribution of convective cloud precipitation is slightly larger in the SCS than the ECS. The contribution of stratus precipitation is slightly larger in the ECS than that in the SCS. Second, the content of cloud particles and precipitation particles in the ECS in June was greater than that in the SCS, while in July and August, the content of cloud and precipitation particles in the ECS was less than that in the SCS. Third, the latent heat profile of the ECS is quite different from that of the SCS. In June, the peak values of evaporation and condensation latent heating rates in the ECS are greater than those in the SCS. In July and August, however, the peak values of evaporation and condensation latent heating rates in the ECS are about 0.05°/h less than those in the SCS.展开更多
The modulation of tropical cyclogenesis over the southern South China Sea （SSCS） by the El Nin o- Southern Oscillation （ENSO） is examined in October–December （OND）, when tropical cyclone （TC） activities are m...The modulation of tropical cyclogenesis over the southern South China Sea （SSCS） by the El Nin o- Southern Oscillation （ENSO） is examined in October–December （OND）, when tropical cyclone （TC） activities are most active in this region. The results reveal that there were more TCs formed over the SSCS during La Nin a years and less TCs during El Nin o years. How different environmental factors （including low-level vorticity, mid-level relative humidity, vertical wind shear, and potential intensity） contribute to this influence is investigated, using a genesis potential （GP） index developed by Emanuel and Nolan. Composite anomalies of the GP index are produced for El Nin o and La Nin a years separately, which could account for the changes of TC frequency over the SSCS in different ENSO phases. The degree of contribution by each factor is determined quantitatively by producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology. The results show that the mid-level relative humidity makes the largest contribution to the ENSO modulation of tropical cyclogenesis over the SSCS. Although warmer sea surface temperatures （SSTs） and larger amount of evaporation from the ocean surface were observed over the SSCS during El Nin o years, anomalous descending motions due to the anomalous Walker circulations inhibited the upward transports of water vapor and led to less moisture contents in the middle troposphere, which suppressed TC formations.展开更多
The three-dimensional structure of precipitation on a seasonal scale in the Asian-Pacific＇s three monsoon regions is investigated based on the tropical rainfall measurement mission （TRMM） data. The results show tha...The three-dimensional structure of precipitation on a seasonal scale in the Asian-Pacific＇s three monsoon regions is investigated based on the tropical rainfall measurement mission （TRMM） data. The results show that： （1） The maximum seasonal variation of the relative proportional difference of convective precipitation and stratiform rain occurs in the East Asian monsoon region, the second occurs in the Indian monsoon region, and the minimum is in the northwest Pacific monsoon region. In both the northwest Pacific mon soon region and the Indian monsoon region, the convective rain is proportionately larger than stratiform rain in all four seasons. （2） Cloud ice reaches its maximum at around 9 km. Cloud water＇s maximum range is between 3 and 4 km. The large value area of precipitation ice is mainly between 4 and 9 km. The precipi tation water particle is concentrated mostly below 4 km. The largest content is from the ground to 2 km. （3） The most remarkable variance of the content of cloud ice in the Indian monsoon region occurs from spring to winter, and the content of cloud water in the northwest Pacific is always higher than that in the other two regions. （4） The latent heat profile has a similar double-peak structure. The first peak is at 4 km and the second peak is at 2 km. In autumn and winter, the latent heat is higher in the northwest Pacific than in other two regions. In all three regions, the release of the latent heat is higher in summer and autumn than in spring and winter.展开更多
High winds in a typhoon over the ocean can produce substantial amounts of spray in the lower part of the atmospheric boundary layer, which can modify the transfer of momentum, heat, and moisture across the air-sea int...High winds in a typhoon over the ocean can produce substantial amounts of spray in the lower part of the atmospheric boundary layer, which can modify the transfer of momentum, heat, and moisture across the air-sea interface. However, the consequent effects on the boundary layer structure and the evolution of the typhoon are largely unknown. The focus of this paper is on the role of sea spray on the storm intensity and the structure of the atmospheric boundary layer. The case study is Typhoon Imbudo in July 2003. The results show that sea spray tends to intensify storms by increasing the sea surface heat fluxes. Moreover, the effects of sea spray are mainly felt in boundary layer. Spray evaporation causes the atmospheric boundary layer to experience cooling and moistening. Sea spray can cause significant effects on the structure of boundary layer. The boundary-layer height over the eyewall area east to the center of Typhoon Imbudo was increased with a maximum up to about 550 m due to sea spray, which is closely related with the enhancements of the heat fluxes, upward motions, and horizontal winds in this region due to sea spray.展开更多
High-frequency oscillations, with periods of about 2 hours, are first identified by applying wavelet analysis to observed minutely wind speeds around the eye and eyewall of tropical cyclones（TCs）. Analysis of a mode...High-frequency oscillations, with periods of about 2 hours, are first identified by applying wavelet analysis to observed minutely wind speeds around the eye and eyewall of tropical cyclones（TCs）. Analysis of a model simulation of Typhoon Hagupit（2008） shows that the oscillations also occur in the TC intensity, vertical motion, convergence activity and air density around the eyewall. Sequences of oscillations in these variables follow a certain order.展开更多
In the artificial intelligence age,multifunctional and intelligent fireproof fabric-based electronics are urgently needed.Herein,a novel thread-shaped all-fabric-based piezoresistive sensor(denoted as TAFPS)with prope...In the artificial intelligence age,multifunctional and intelligent fireproof fabric-based electronics are urgently needed.Herein,a novel thread-shaped all-fabric-based piezoresistive sensor(denoted as TAFPS)with properties such as flame retardancy,firewarning,and piezoresistivity is proposed,which is composed of an inner nickel-plated fabric electrode,a multifunctional double helix fabric,and an external flame-retardant encapsulation fabric.Owing to the multiple flame-retardant properties of glass fiber tubular fabric,aminated carbon nanotubes(ACNTs),and ammonium polyphosphate,the char residue of the TAFPS reaches40.3 wt%at 800℃.In addition,the heat-sensitive effect of ACNTs during combustion causes a rapid decrease in the TAFPS resistance,triggering the fire alarm system within 2 s.Additionally,benefiting from the force-sensitive behavior of the double helix layer and tightly wrapped pattern of the external heat-shrinkable tubular fabric,TAFPS demonstrated a high sensitivity of4.40 kPa^(-1)(0–5.81 k Pa)and good stability for 10000 s.Considering its excellent flame resistance,high sensitivity,and agreeable stability,the developed TAFPS can be integrated into fire suits to monitor the exercise training process and the external fire environment.This work offers a novel approach for fabricating all-fabric-based piezoresistive sensors in the future for fire prevention and fire alarms,with promising applications in fire protection,the Internet of Things,and smart apparel.展开更多
Climatological relationships among the tropical cyclone(TC)frequency,duration,intensity and activity regions over the Western Pacific are explored based on long-term best track data.Frequent TC occurrence does not nec...Climatological relationships among the tropical cyclone(TC)frequency,duration,intensity and activity regions over the Western Pacific are explored based on long-term best track data.Frequent TC occurrence does not necessarily imply a long duration of TCs in the same periods.Three types of relationship between TC number and duration in the period 1945-2007 were identified in this study:low frequency and short duration during 1945-1955(Period I);high frequency and short duration in the 1960s(Period II);and high frequency and long duration in the 1990s(Period III).TC activity regions differed among the three periods.During Period I,the main activity regions were over the ocean east of the Philippines(120°-140°E).During period II,two prevailing storm tracks extended west-northwest between 110° and 147°E.During period III,TCs had an extensive activity region from 110° to 160°E.TC intensity is related closely to activity regions.Most strong TCs developed over the ocean far from the Philippines,and had a northwestward track.Our results also show that the relationships between TC frequency,duration and their active regions are modulated strongly by broad-scale vertical motion,geopotential height and horizontal wind anomalies.展开更多
目的探讨退变性脊柱后凸畸形顶椎邻近节段黄韧带骨化(ossification of ligamentum flavum,OLF)的发生率及其分布特征。方法收集2018年1月至2021年12月74例行手术治疗的退变性脊柱后凸畸形患者的临床资料,依据全脊柱正侧位X线片测量术前...目的探讨退变性脊柱后凸畸形顶椎邻近节段黄韧带骨化(ossification of ligamentum flavum,OLF)的发生率及其分布特征。方法收集2018年1月至2021年12月74例行手术治疗的退变性脊柱后凸畸形患者的临床资料,依据全脊柱正侧位X线片测量术前后凸Cobb角并记录后凸形态。分别观察术前全脊柱CT及全脊柱MRI,统计在后凸顶椎近端和远端邻近3个节段内OLF的发生情况,记录发生的位置及其类型。结果74例患者中54例(73%)在后凸顶椎近端和远端邻近3个节段内发生了OLF,男5例、女49例,年龄(61.4±6.8)岁(范围47~81岁),后凸Cobb角为49.5°±21.2°;20例未发生OLF的患者,男3例、女17例,年龄(56.1±7.5)岁(范围40~68岁),后凸Cobb角为52.1°±19.1°。两组患者年龄的差异有统计学意义(t=2.92,P=0.005),而后凸Cobb角的差异无统计学意义(t=0.48,P=0.634)。40~49岁组、50~59岁组、60~69岁组和≥70岁组患者OLF发生率分别为50%、62%、82%和100%。74例患者中9例为角状后凸,其中8例(89%)发生OLF;65例为非角状后凸,46例(71%)发生OLF,差异无统计学意义(χ^(2)=1.32,P=0.251)。54例发生OLF的患者中合并后纵韧带骨化(ossification of the posterior longitudinal ligament,OPLL)者5例(9%),合并硬膜骨化者20例(37%);43例(80%)发生在顶椎近端、6例(11%)发生在顶椎远端、5例(9%)患者顶椎近端和远端均发生;59%(32/54)的患者OLF发生于顶椎邻近第1个节段、50%(27/54)的患者发生于顶椎邻近第2个节段、28%(15/54)的患者发生于顶椎邻近第3个节段。结论退变性脊柱后凸畸形中约73%的患者顶椎邻近3个节段内可能发生OLF,且多位于顶椎近端以及顶椎邻近的2个节段内。展开更多
基金The National Natural Science Foundation of China under contract No. 40875020the National Basic Research Program of China under contract No. 2011CB403500the NSFC-Guangdong Joint Fund Program under contract No. U0733002
文摘By using the TRMM and QuikSCAT datathe characteristics of the 2–8 day high frequency atmospheric variability over the South China Sea are studied in this paper.It’s found that： （1） the 2–8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon （SCSSM）,but also after the retreat of the SCSSM.It reaches its peak around July to August;（2） the 2–8 day high frequency signals exhibit strong intermittent features;（3） During El Nino years,the 2–8 day high frequency signals are active only in the periods of the SCSSM.During La Nina years,the 2–8 day high frequency signals are obviously not only in periods of the SCSSM,but also after the retreat of the SCSSM.During the SCSSM periods,the 2–8 day high frequency signals in El Nino years are much stronger than that in La Nina years;（4） During spring to early summer,most of 2–8 day signals propagate southward and eastward,during midsummer to autumn,however,most of 2–8-day signals propagate northward and westward;（5） The 2–8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS.
基金The National Key Basic Research Program of China under contract No.2014CB953903the National Basic Research Programof China under contract No.2011CB403500+1 种基金the National Natural Science Foundation of China under contract Nos 40775066 and 41275145the Fundamental Research Funds for the Central Universities under contract No.13lgjc03
文摘The three-dimensional structures of summer precipitation over the South China Sea （SCS） and the East China Sea （ECS） are investigated based on tropical rainfall measurement mission （TRMM）. The primary results are as follows. First, both the convective and stratiform precipitation rates in the SCS are much higher than those of the ECS. The contribution of the convective cloud precipitation to the surface precipitation is primarily over the SCS and the ECS with a proportion of about 70%, but the contribution of convective cloud precipitation is slightly larger in the SCS than the ECS. The contribution of stratus precipitation is slightly larger in the ECS than that in the SCS. Second, the content of cloud particles and precipitation particles in the ECS in June was greater than that in the SCS, while in July and August, the content of cloud and precipitation particles in the ECS was less than that in the SCS. Third, the latent heat profile of the ECS is quite different from that of the SCS. In June, the peak values of evaporation and condensation latent heating rates in the ECS are greater than those in the SCS. In July and August, however, the peak values of evaporation and condensation latent heating rates in the ECS are about 0.05°/h less than those in the SCS.
基金The National Basic Research Program of China under contract No. 2011CB403500the fund from the State Key Laboratory of Satellite Ocean Environmental Dynamics (Second Institute of Oceanography) under contract No. SOED1108+1 种基金the fund from the State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology) under contract No. LED1002the tropical marine meteorology fund from the Institute of Tropical and Marine Meteorology and the Fundamental Research Funds for the Central Universities under contract No. 111gpy13
文摘The modulation of tropical cyclogenesis over the southern South China Sea （SSCS） by the El Nin o- Southern Oscillation （ENSO） is examined in October–December （OND）, when tropical cyclone （TC） activities are most active in this region. The results reveal that there were more TCs formed over the SSCS during La Nin a years and less TCs during El Nin o years. How different environmental factors （including low-level vorticity, mid-level relative humidity, vertical wind shear, and potential intensity） contribute to this influence is investigated, using a genesis potential （GP） index developed by Emanuel and Nolan. Composite anomalies of the GP index are produced for El Nin o and La Nin a years separately, which could account for the changes of TC frequency over the SSCS in different ENSO phases. The degree of contribution by each factor is determined quantitatively by producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology. The results show that the mid-level relative humidity makes the largest contribution to the ENSO modulation of tropical cyclogenesis over the SSCS. Although warmer sea surface temperatures （SSTs） and larger amount of evaporation from the ocean surface were observed over the SSCS during El Nin o years, anomalous descending motions due to the anomalous Walker circulations inhibited the upward transports of water vapor and led to less moisture contents in the middle troposphere, which suppressed TC formations.
基金The National Natural Science Foundation of China under contract No.41275060the National Key Basic Research Program of China under contract No.2014CB953903+2 种基金the National Basic Research Program of China under contract No.2011CB403500the Fundamental Re-search Funds for the Central Universities of China under contract No.13lgjc03the National Natural Science Foundation of China under contract No.41275145
文摘The three-dimensional structure of precipitation on a seasonal scale in the Asian-Pacific＇s three monsoon regions is investigated based on the tropical rainfall measurement mission （TRMM） data. The results show that： （1） The maximum seasonal variation of the relative proportional difference of convective precipitation and stratiform rain occurs in the East Asian monsoon region, the second occurs in the Indian monsoon region, and the minimum is in the northwest Pacific monsoon region. In both the northwest Pacific mon soon region and the Indian monsoon region, the convective rain is proportionately larger than stratiform rain in all four seasons. （2） Cloud ice reaches its maximum at around 9 km. Cloud water＇s maximum range is between 3 and 4 km. The large value area of precipitation ice is mainly between 4 and 9 km. The precipi tation water particle is concentrated mostly below 4 km. The largest content is from the ground to 2 km. （3） The most remarkable variance of the content of cloud ice in the Indian monsoon region occurs from spring to winter, and the content of cloud water in the northwest Pacific is always higher than that in the other two regions. （4） The latent heat profile has a similar double-peak structure. The first peak is at 4 km and the second peak is at 2 km. In autumn and winter, the latent heat is higher in the northwest Pacific than in other two regions. In all three regions, the release of the latent heat is higher in summer and autumn than in spring and winter.
基金The National Natural Science Foundation of China under contract No.41375050,the National Natural Science Foundation of China under contract No.40875020the National Basic Research Program of Chinaunder contract No.2011CB403500
文摘High winds in a typhoon over the ocean can produce substantial amounts of spray in the lower part of the atmospheric boundary layer, which can modify the transfer of momentum, heat, and moisture across the air-sea interface. However, the consequent effects on the boundary layer structure and the evolution of the typhoon are largely unknown. The focus of this paper is on the role of sea spray on the storm intensity and the structure of the atmospheric boundary layer. The case study is Typhoon Imbudo in July 2003. The results show that sea spray tends to intensify storms by increasing the sea surface heat fluxes. Moreover, the effects of sea spray are mainly felt in boundary layer. Spray evaporation causes the atmospheric boundary layer to experience cooling and moistening. Sea spray can cause significant effects on the structure of boundary layer. The boundary-layer height over the eyewall area east to the center of Typhoon Imbudo was increased with a maximum up to about 550 m due to sea spray, which is closely related with the enhancements of the heat fluxes, upward motions, and horizontal winds in this region due to sea spray.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41375050, 41405048 and 41205032)the China National Basic Research Program (Grant Nos. 2011CB403500 and 2014CB953904)
文摘High-frequency oscillations, with periods of about 2 hours, are first identified by applying wavelet analysis to observed minutely wind speeds around the eye and eyewall of tropical cyclones（TCs）. Analysis of a model simulation of Typhoon Hagupit（2008） shows that the oscillations also occur in the TC intensity, vertical motion, convergence activity and air density around the eyewall. Sequences of oscillations in these variables follow a certain order.
基金supported by the National Natural Science Foundation of China(Grant No.52175554)Young Top Talent Project of the Hebei Provincial Department of Education(Grant No.BJK2023116)+2 种基金the Central Guiding Local Science and Technology Development Fund Project(Grant No.236Z4901G)the Natural Science Foundation of Hebei Province(Grant No.F2021409007)the School Research Fund Project(Grant No.YKY-2023-34)。
文摘In the artificial intelligence age,multifunctional and intelligent fireproof fabric-based electronics are urgently needed.Herein,a novel thread-shaped all-fabric-based piezoresistive sensor(denoted as TAFPS)with properties such as flame retardancy,firewarning,and piezoresistivity is proposed,which is composed of an inner nickel-plated fabric electrode,a multifunctional double helix fabric,and an external flame-retardant encapsulation fabric.Owing to the multiple flame-retardant properties of glass fiber tubular fabric,aminated carbon nanotubes(ACNTs),and ammonium polyphosphate,the char residue of the TAFPS reaches40.3 wt%at 800℃.In addition,the heat-sensitive effect of ACNTs during combustion causes a rapid decrease in the TAFPS resistance,triggering the fire alarm system within 2 s.Additionally,benefiting from the force-sensitive behavior of the double helix layer and tightly wrapped pattern of the external heat-shrinkable tubular fabric,TAFPS demonstrated a high sensitivity of4.40 kPa^(-1)(0–5.81 k Pa)and good stability for 10000 s.Considering its excellent flame resistance,high sensitivity,and agreeable stability,the developed TAFPS can be integrated into fire suits to monitor the exercise training process and the external fire environment.This work offers a novel approach for fabricating all-fabric-based piezoresistive sensors in the future for fire prevention and fire alarms,with promising applications in fire protection,the Internet of Things,and smart apparel.
基金supported by the National Natural Science Foundation of China(40875020)the NSFC-Guangdong Joint Fund Program(U0733002)the National Basic Research Program of China(2009CB421404)
文摘Climatological relationships among the tropical cyclone(TC)frequency,duration,intensity and activity regions over the Western Pacific are explored based on long-term best track data.Frequent TC occurrence does not necessarily imply a long duration of TCs in the same periods.Three types of relationship between TC number and duration in the period 1945-2007 were identified in this study:low frequency and short duration during 1945-1955(Period I);high frequency and short duration in the 1960s(Period II);and high frequency and long duration in the 1990s(Period III).TC activity regions differed among the three periods.During Period I,the main activity regions were over the ocean east of the Philippines(120°-140°E).During period II,two prevailing storm tracks extended west-northwest between 110° and 147°E.During period III,TCs had an extensive activity region from 110° to 160°E.TC intensity is related closely to activity regions.Most strong TCs developed over the ocean far from the Philippines,and had a northwestward track.Our results also show that the relationships between TC frequency,duration and their active regions are modulated strongly by broad-scale vertical motion,geopotential height and horizontal wind anomalies.
文摘目的探讨退变性脊柱后凸畸形顶椎邻近节段黄韧带骨化(ossification of ligamentum flavum,OLF)的发生率及其分布特征。方法收集2018年1月至2021年12月74例行手术治疗的退变性脊柱后凸畸形患者的临床资料,依据全脊柱正侧位X线片测量术前后凸Cobb角并记录后凸形态。分别观察术前全脊柱CT及全脊柱MRI,统计在后凸顶椎近端和远端邻近3个节段内OLF的发生情况,记录发生的位置及其类型。结果74例患者中54例(73%)在后凸顶椎近端和远端邻近3个节段内发生了OLF,男5例、女49例,年龄(61.4±6.8)岁(范围47~81岁),后凸Cobb角为49.5°±21.2°;20例未发生OLF的患者,男3例、女17例,年龄(56.1±7.5)岁(范围40~68岁),后凸Cobb角为52.1°±19.1°。两组患者年龄的差异有统计学意义(t=2.92,P=0.005),而后凸Cobb角的差异无统计学意义(t=0.48,P=0.634)。40~49岁组、50~59岁组、60~69岁组和≥70岁组患者OLF发生率分别为50%、62%、82%和100%。74例患者中9例为角状后凸,其中8例(89%)发生OLF;65例为非角状后凸,46例(71%)发生OLF,差异无统计学意义(χ^(2)=1.32,P=0.251)。54例发生OLF的患者中合并后纵韧带骨化(ossification of the posterior longitudinal ligament,OPLL)者5例(9%),合并硬膜骨化者20例(37%);43例(80%)发生在顶椎近端、6例(11%)发生在顶椎远端、5例(9%)患者顶椎近端和远端均发生;59%(32/54)的患者OLF发生于顶椎邻近第1个节段、50%(27/54)的患者发生于顶椎邻近第2个节段、28%(15/54)的患者发生于顶椎邻近第3个节段。结论退变性脊柱后凸畸形中约73%的患者顶椎邻近3个节段内可能发生OLF,且多位于顶椎近端以及顶椎邻近的2个节段内。
