A stratus-sea fog event that occurred over the Yellow and East China Seas on 3 June 2011 is investigated using observations and a numerical model, with a focus on the effects of background circulation and Sea Surface ...A stratus-sea fog event that occurred over the Yellow and East China Seas on 3 June 2011 is investigated using observations and a numerical model, with a focus on the effects of background circulation and Sea Surface Temperature Front （SSTF） on the transition of stratus into sea fog. Southerly winds of a synoptic high-pressure circulation transport water vapor to the Yellow Sea, creating conditions favorable for sea fog/stratus formation. The subsidence from the high-pressure contributes to the temperature inversion at the top of the stratus. The SSTF forces a secondary circulation within the ABL （Atmospheric Boundary Layer）, the sinking branch of which on the cold flank of SSTF helps lower the stratus layer fiLrther to reach the sea surface. The cooling effect over the cold sea surface counteracts the adiabatic warming induced by subsidence. The secondary circulation becomes weak and the fog patches are shrtmk heavily with the smoothed SSTE A conceptual model is proposed for the transition of stratus into sea fog over the Yellow and East China Seas. Finally, the analyses suggest that sea fog frequency will probably decrease due to the weakened SSTF and the reduced subsidence of secondary circulation under global wanning.展开更多
General elections held in October 1951 can be considered as a milestone in British political history, and from an international point of view, the return to power of Conservatives after the defeats of 1945 and 1950 re...General elections held in October 1951 can be considered as a milestone in British political history, and from an international point of view, the return to power of Conservatives after the defeats of 1945 and 1950 represents an event of considerable relevance. Based on Italian archival sources, this paper analyses Tommaso Gallarati Scotti＇s （Italian ambassador to the UK） view during the electoral campaign, as a part of a diplomatic action aimed at resuming the traditional Anglo-Italian friendship brutally interrupted on June 10, 1940, at the time of fascist ＂stab in the back＂： a hard task to accomplish, even after the resumption of full diplomatic relations between Rome and London, in 1947.展开更多
De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess Plateau.There are different views about the defarming method,and also various...De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess Plateau.There are different views about the defarming method,and also various de-farming patterns have been put into practice.This paper takes the Yangou Watershed in Shaanxi Province of China as a case for studying the comprehensive benefits of transforming slope farmland to terraces.Based on the day-by-day meteorological data of the Yan'an station in 2005 and the data of terrain features,soil and land use data of the Yangou Watershed,the impact of transforming slope farmland on terraces were simulated and analyzed in aspects of yield increase and water-soil conservation under different topographic conditions with the aid of software WIN-YIELD.Furthermore,an empirical analysis was applied to study the effects of transforming slope farmland to terraces in the Yangou Watershed.The results show that:(1) The bigger the topographic gradient is,the more remarkable benefits it has in yield increase and water-soil conservation.(2) Farmland with slope below 5° could be retained,but farmland with slope above 15° should be converted to forest or grassland as soon as possible.(3) Transforming slope farmland to terraces has the same remarkable effects as the current policy of "Relieving and de-farming" in improving agricultural production conditions,safeguarding food security,raising permanent vegetation coverage rate,and preventing soil and water loss.Besides,it is more cost-effective than the policy of "Relieving and de-farming".It's strongly suggested that the policy of transforming slope farmland to terraces be carried out on the Loess Plateau without delay.展开更多
Deformation and failure of high slope impact the construction and operation safety of highway in the mountainous areas. The deformation and failure are mainly caused by poor design which normally has not well combined...Deformation and failure of high slope impact the construction and operation safety of highway in the mountainous areas. The deformation and failure are mainly caused by poor design which normally has not well combined with the geological conditions and unplanned construction. Therefore, effective design and construction management should be conducted for ensuring a successful construction without damage and risk. In light of the reality of high slope construction along highway in the Huangshan area, this paper proposes a technical procedure for dynamic design and construction management of high slopes along highway in the mountainous area. The proposed construction management scheme is divided into three phases, i.e., 1) design phase, 2) preparation phase of excavation, and 3) construction phase. During the design phase, experiences and lessons learnt from the design and construction of other high slopes along highway in the same region are summarized. The number of slopes and slope height should be optimized from the aspects of route selection and route form. During the preparation phase of excavation, "Excavation Permit Management System" should be adopted, and construction scheme should be made by the construction unit, then the scientific research and design unit determine whether it guarantees slope stability and makes optimization measures. During the construction phase, the scientific research unit would make proposal of optimization design, and apply the achievements of scientific research into practice through common efforts of various units based on the understanding of excavation and investigation. The management system mentioned above is adopted to conduct dynamic design and construction management for more than 90 slopes along the Huangshan - Taling - Taolin Expressway, and successful results of application have been achieved.展开更多
文摘A stratus-sea fog event that occurred over the Yellow and East China Seas on 3 June 2011 is investigated using observations and a numerical model, with a focus on the effects of background circulation and Sea Surface Temperature Front （SSTF） on the transition of stratus into sea fog. Southerly winds of a synoptic high-pressure circulation transport water vapor to the Yellow Sea, creating conditions favorable for sea fog/stratus formation. The subsidence from the high-pressure contributes to the temperature inversion at the top of the stratus. The SSTF forces a secondary circulation within the ABL （Atmospheric Boundary Layer）, the sinking branch of which on the cold flank of SSTF helps lower the stratus layer fiLrther to reach the sea surface. The cooling effect over the cold sea surface counteracts the adiabatic warming induced by subsidence. The secondary circulation becomes weak and the fog patches are shrtmk heavily with the smoothed SSTE A conceptual model is proposed for the transition of stratus into sea fog over the Yellow and East China Seas. Finally, the analyses suggest that sea fog frequency will probably decrease due to the weakened SSTF and the reduced subsidence of secondary circulation under global wanning.
文摘General elections held in October 1951 can be considered as a milestone in British political history, and from an international point of view, the return to power of Conservatives after the defeats of 1945 and 1950 represents an event of considerable relevance. Based on Italian archival sources, this paper analyses Tommaso Gallarati Scotti＇s （Italian ambassador to the UK） view during the electoral campaign, as a part of a diplomatic action aimed at resuming the traditional Anglo-Italian friendship brutally interrupted on June 10, 1940, at the time of fascist ＂stab in the back＂： a hard task to accomplish, even after the resumption of full diplomatic relations between Rome and London, in 1947.
基金the National Natural Science Foundation of China(No.40771086)National Key Technology R&D Program of China (No.2006BAD09B10)Knowledge Innovation Project of Chinese Academy of Sciences (No.KZCX2-XB2-05-01)
文摘De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess Plateau.There are different views about the defarming method,and also various de-farming patterns have been put into practice.This paper takes the Yangou Watershed in Shaanxi Province of China as a case for studying the comprehensive benefits of transforming slope farmland to terraces.Based on the day-by-day meteorological data of the Yan'an station in 2005 and the data of terrain features,soil and land use data of the Yangou Watershed,the impact of transforming slope farmland on terraces were simulated and analyzed in aspects of yield increase and water-soil conservation under different topographic conditions with the aid of software WIN-YIELD.Furthermore,an empirical analysis was applied to study the effects of transforming slope farmland to terraces in the Yangou Watershed.The results show that:(1) The bigger the topographic gradient is,the more remarkable benefits it has in yield increase and water-soil conservation.(2) Farmland with slope below 5° could be retained,but farmland with slope above 15° should be converted to forest or grassland as soon as possible.(3) Transforming slope farmland to terraces has the same remarkable effects as the current policy of "Relieving and de-farming" in improving agricultural production conditions,safeguarding food security,raising permanent vegetation coverage rate,and preventing soil and water loss.Besides,it is more cost-effective than the policy of "Relieving and de-farming".It's strongly suggested that the policy of transforming slope farmland to terraces be carried out on the Loess Plateau without delay.
文摘Deformation and failure of high slope impact the construction and operation safety of highway in the mountainous areas. The deformation and failure are mainly caused by poor design which normally has not well combined with the geological conditions and unplanned construction. Therefore, effective design and construction management should be conducted for ensuring a successful construction without damage and risk. In light of the reality of high slope construction along highway in the Huangshan area, this paper proposes a technical procedure for dynamic design and construction management of high slopes along highway in the mountainous area. The proposed construction management scheme is divided into three phases, i.e., 1) design phase, 2) preparation phase of excavation, and 3) construction phase. During the design phase, experiences and lessons learnt from the design and construction of other high slopes along highway in the same region are summarized. The number of slopes and slope height should be optimized from the aspects of route selection and route form. During the preparation phase of excavation, "Excavation Permit Management System" should be adopted, and construction scheme should be made by the construction unit, then the scientific research and design unit determine whether it guarantees slope stability and makes optimization measures. During the construction phase, the scientific research unit would make proposal of optimization design, and apply the achievements of scientific research into practice through common efforts of various units based on the understanding of excavation and investigation. The management system mentioned above is adopted to conduct dynamic design and construction management for more than 90 slopes along the Huangshan - Taling - Taolin Expressway, and successful results of application have been achieved.
