Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ...Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.展开更多
The surface and atmospheric heating fields over the Qinghai-Xizang Plateau are computed by using the observational data of solar radiation during 1982—1983.The mian results are as follows:The central and northern par...The surface and atmospheric heating fields over the Qinghai-Xizang Plateau are computed by using the observational data of solar radiation during 1982—1983.The mian results are as follows:The central and northern parts of the Plateau act as heat sinks in winter from November to January.Both eastern and south- ern parts of the Plateau are of heat sources.In summer,the main part of the Plateau acts as a strong heat source,and the center of the heating field is in the southeastern Plateau.However the main part of the Plateau acts as a heat sink for the atmospheric heating fields from October to March.The maximum intensity of the atmospheric heat sink over the central Plateau appears in December and January.From April to September,the main part of the Plateau acts as a heat source for the atmospheric heating fields.展开更多
This study compares two rainstorms that swept through Henan Province of China in July 2021 and August 1975.The heavy rainfall and related synoptic systems and processes are diagnosed based on hourly ERA5 reanalysis da...This study compares two rainstorms that swept through Henan Province of China in July 2021 and August 1975.The heavy rainfall and related synoptic systems and processes are diagnosed based on hourly ERA5 reanalysis data and precipitation observations from the China Meteorological Administration.It is estimated that most of the daily rainfall in Henan was caused by synoptic-scale precipitation,with the sub-synoptic convective rainfall intermittently dominating some of the hourly total rainfall.The rainband moved at about 2 m s^(-1) during the July 2021 rainstorm,whereas it was almost stationary during the August 1975 rainstorm when the heavy rainfall was concentrated in southern Henan.A double-typhoon circulation pattern with a subtropical high over the Bohai and Yellow Seas was observed during both rainstorms.The heavy rainfall during the July 2021 event was controlled remotely by Typhoons Cempaka and In-Fa,which provided a path for the transport of moisture via the southerly jet associated with Typhoon Cempaka and the easterly(or southeasterly)jet associated with Typhoon In-Fa.The rainstorm in August1975 was caused more directly by Typhoon Nina,which made landfall in Fujian Province and moved toward Henan Province.The rainfall around the inverted trough of the motionless Typhoon Nina produced a cumulative effect.The two rainstorms also differed in their circulation patterns in the upper troposphere.The intrusion of high potential vorticity air over Central China occurred in the July 2021 extreme rainstorm,whereas the South Asian high was enhanced and biased further north during the August 1975 rainstorm.Further analysis showed that the northward and westward transport of moisture took place during the July 2021 rainstorm,whereas the westward transport of moisture from the east of Henan dominated near the inverted trough of Typhoon Nina during the August 1975 rainstorm.展开更多
By using China National Climate Center’s 74 circulation characteristics, DERF2.0, BCC-CSM models and Wenzhou Typhoon Network data, and using linear regression, correlation coefficients and other research methods, the...By using China National Climate Center’s 74 circulation characteristics, DERF2.0, BCC-CSM models and Wenzhou Typhoon Network data, and using linear regression, correlation coefficients and other research methods, the variations about typhoon frequency in July from 1951 to 2020 and the large-scale circulation system in July 2020 are analyzed. The results show that 1) in the recent 70 years, the frequency of typhoon generation has slowly decreased, while the frequency of landing typhoons in China has slowly increased;2) typhoon frequency has varying degrees of negative correlation with the intensity of subtropical high in different regions of the northern hemisphere, especially with the area index and intensity index of the South China Sea subtropical high;3) in July 2020, the area and intensity of the subtropical high in the Northwest Pacific were abnormally large and strong. Easterly winds prevailed in the tropics, and the cross-equatorial airflow was weak, resulting in a severe reduction in the frequency of typhoon generation, leading to “no-typhoon” events.展开更多
The temperature change trends in January and July are analyzed and the results show that the trends descend in July but ascend in January except in South China and Southwest China. The relation between the temperature...The temperature change trends in January and July are analyzed and the results show that the trends descend in July but ascend in January except in South China and Southwest China. The relation between the temperature in January and July are discussed by using the wavelet. The results show that the trend phase in July and January are nearly in-phase in Southwest and South China, but are out-of-phase in other regions. Reconstruction of original temperature series in each of the regions indicates that their change trends are consistent with the original temperature series.展开更多
As a famous English contemporary women writer, Doris Lessing always puts her attention on the female characters that live in South Africa. Their lives are pathetic and sad. This thesis tries to analyze one of Lessing&...As a famous English contemporary women writer, Doris Lessing always puts her attention on the female characters that live in South Africa. Their lives are pathetic and sad. This thesis tries to analyze one of Lessing's short stories— Winter in July from Lacan's three Orders approach. Lessing is a feminist, but the deeper description of the desire and struggle in men's inner world in her works is also remarkable.展开更多
The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is c...The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is concluded that on the one hand, the northward jump of the jet causes the precipitation belt to move northward from the middle and lower reaches of the Yangtze River valley and withdraw during the Mei-yu season; on the other hand, the westward movement of the jet core has no correspondence with withdrawal of the Mei-yu season. However, the earlier or later occurrence of the westward movement of the jet has an influence on the process of the rain belt moving northward than the northward jump of the jet： the rain belt moves northward from the middle-lower Yangtze River valley to the Huaihe River and then to an area between the Yellow River and Huaihe River during years when the time of the westward movement of the jet core is later than that of the northward jump of the jet and from the middle-lower Yangtze River valley to an area between the Yellow River and Huaihe River in other years. Further analysis shows that： （1） The northward jump of the jet and the westward movement of the East Asian westerly jet core causes significant variation of the general atmospheric circulation in middle latitudes and water vapor transport from the western Pacific, but not from the Bay of Bengal. （2） Impact of the northward jump and the westward movement of the East Asian westerly jet core on circulation are different, therefore, water vapor transport from the western Pacific and its impact on the rain belt are different. The earlier or later occurrence of the westward movement of the jet core than the northward jump of the jet causes the process of circulation and water vapor transport to be different which produces a different process of the rain belt moving northward.展开更多
文摘Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.
文摘The surface and atmospheric heating fields over the Qinghai-Xizang Plateau are computed by using the observational data of solar radiation during 1982—1983.The mian results are as follows:The central and northern parts of the Plateau act as heat sinks in winter from November to January.Both eastern and south- ern parts of the Plateau are of heat sources.In summer,the main part of the Plateau acts as a strong heat source,and the center of the heating field is in the southeastern Plateau.However the main part of the Plateau acts as a heat sink for the atmospheric heating fields from October to March.The maximum intensity of the atmospheric heat sink over the central Plateau appears in December and January.From April to September,the main part of the Plateau acts as a heat source for the atmospheric heating fields.
基金Supported by the National Key Research and Development Program of China (2021YFC3000903)National Natural Science Foundation of China (42030605)。
文摘This study compares two rainstorms that swept through Henan Province of China in July 2021 and August 1975.The heavy rainfall and related synoptic systems and processes are diagnosed based on hourly ERA5 reanalysis data and precipitation observations from the China Meteorological Administration.It is estimated that most of the daily rainfall in Henan was caused by synoptic-scale precipitation,with the sub-synoptic convective rainfall intermittently dominating some of the hourly total rainfall.The rainband moved at about 2 m s^(-1) during the July 2021 rainstorm,whereas it was almost stationary during the August 1975 rainstorm when the heavy rainfall was concentrated in southern Henan.A double-typhoon circulation pattern with a subtropical high over the Bohai and Yellow Seas was observed during both rainstorms.The heavy rainfall during the July 2021 event was controlled remotely by Typhoons Cempaka and In-Fa,which provided a path for the transport of moisture via the southerly jet associated with Typhoon Cempaka and the easterly(or southeasterly)jet associated with Typhoon In-Fa.The rainstorm in August1975 was caused more directly by Typhoon Nina,which made landfall in Fujian Province and moved toward Henan Province.The rainfall around the inverted trough of the motionless Typhoon Nina produced a cumulative effect.The two rainstorms also differed in their circulation patterns in the upper troposphere.The intrusion of high potential vorticity air over Central China occurred in the July 2021 extreme rainstorm,whereas the South Asian high was enhanced and biased further north during the August 1975 rainstorm.Further analysis showed that the northward and westward transport of moisture took place during the July 2021 rainstorm,whereas the westward transport of moisture from the east of Henan dominated near the inverted trough of Typhoon Nina during the August 1975 rainstorm.
文摘By using China National Climate Center’s 74 circulation characteristics, DERF2.0, BCC-CSM models and Wenzhou Typhoon Network data, and using linear regression, correlation coefficients and other research methods, the variations about typhoon frequency in July from 1951 to 2020 and the large-scale circulation system in July 2020 are analyzed. The results show that 1) in the recent 70 years, the frequency of typhoon generation has slowly decreased, while the frequency of landing typhoons in China has slowly increased;2) typhoon frequency has varying degrees of negative correlation with the intensity of subtropical high in different regions of the northern hemisphere, especially with the area index and intensity index of the South China Sea subtropical high;3) in July 2020, the area and intensity of the subtropical high in the Northwest Pacific were abnormally large and strong. Easterly winds prevailed in the tropics, and the cross-equatorial airflow was weak, resulting in a severe reduction in the frequency of typhoon generation, leading to “no-typhoon” events.
文摘The temperature change trends in January and July are analyzed and the results show that the trends descend in July but ascend in January except in South China and Southwest China. The relation between the temperature in January and July are discussed by using the wavelet. The results show that the trend phase in July and January are nearly in-phase in Southwest and South China, but are out-of-phase in other regions. Reconstruction of original temperature series in each of the regions indicates that their change trends are consistent with the original temperature series.
文摘As a famous English contemporary women writer, Doris Lessing always puts her attention on the female characters that live in South Africa. Their lives are pathetic and sad. This thesis tries to analyze one of Lessing's short stories— Winter in July from Lacan's three Orders approach. Lessing is a feminist, but the deeper description of the desire and struggle in men's inner world in her works is also remarkable.
基金supported by the National Natural Science Foundation of China (Grant No.40675041)
文摘The impact of the northward jump and westward movement of the East Asian westerly jet core fi：om the westem Pacific Ocean to the Qinghai-Tibet Plateau on precipitation distribution of eastem China is studied. It is concluded that on the one hand, the northward jump of the jet causes the precipitation belt to move northward from the middle and lower reaches of the Yangtze River valley and withdraw during the Mei-yu season; on the other hand, the westward movement of the jet core has no correspondence with withdrawal of the Mei-yu season. However, the earlier or later occurrence of the westward movement of the jet has an influence on the process of the rain belt moving northward than the northward jump of the jet： the rain belt moves northward from the middle-lower Yangtze River valley to the Huaihe River and then to an area between the Yellow River and Huaihe River during years when the time of the westward movement of the jet core is later than that of the northward jump of the jet and from the middle-lower Yangtze River valley to an area between the Yellow River and Huaihe River in other years. Further analysis shows that： （1） The northward jump of the jet and the westward movement of the East Asian westerly jet core causes significant variation of the general atmospheric circulation in middle latitudes and water vapor transport from the western Pacific, but not from the Bay of Bengal. （2） Impact of the northward jump and the westward movement of the East Asian westerly jet core on circulation are different, therefore, water vapor transport from the western Pacific and its impact on the rain belt are different. The earlier or later occurrence of the westward movement of the jet core than the northward jump of the jet causes the process of circulation and water vapor transport to be different which produces a different process of the rain belt moving northward.
