Using data from automatic surface weather stations, buoys, lidar and Doppler, the diurnal variation and the three-dimensional structure of the sea breezes near the sailing sites of the Good Luck Beijing- 2006 Qingdao ...Using data from automatic surface weather stations, buoys, lidar and Doppler, the diurnal variation and the three-dimensional structure of the sea breezes near the sailing sites of the Good Luck Beijing- 2006 Qingdao International Regatta from 18 to 31 August 2006 are analyzed. Results show that excluding rainy days and days affected by typhoon, the sea breezes occur nearly every day during this period. When Qingdao is located at the edge of the subtropical high at 500 hPa, the sea breeze is usually stronger, around 3-4 m s^-1. It starts at around 1100 to 1300 LST and lasts about 6 hours. The direction of the sea breeze tends to be southeasterly. When Qingdao is under the control of the subtropical high, the sea breeze is usually weaker, less than 2.5 m s^-1 throughout the day, and begins later, between 1300 and 1500 LST. In this case, the direction of the sea breeze is variable from easterly to southeasterly. Most sea breezes in Qingdao are very shallow, up to 300 meters deep. Strong sea breezes can reach 1.5 km in depth and can push as far as 100 km inland. If the Huanghai sea breeze moves inland and meets the sea breeze of the Jiaozhou Bay in the western part of Qingdao, the sea breeze will strengthen and form three boundaries due to the interaction of the two sea breezes.展开更多
The election of Donald Trump as US President worries some of the people about reversal of globalization.As Trump talked a lot against globalization,they believe that his election is the beginning of the end of globali...The election of Donald Trump as US President worries some of the people about reversal of globalization.As Trump talked a lot against globalization,they believe that his election is the beginning of the end of globalization.Furthermore,a series of events such as the Brexit and展开更多
This paper attempts to analyze the symbolism that is embodied in"Sailing to Byzantium"and to further understand the spiritual freedom W. B. Yeats expressed in the poem. Studying the contrasts of the symbols ...This paper attempts to analyze the symbolism that is embodied in"Sailing to Byzantium"and to further understand the spiritual freedom W. B. Yeats expressed in the poem. Studying the contrasts of the symbols and the eternity and holy spirit carried by Byzantium, we can understand Yeats' life philosophy, and finally reach his spiritual freedom which perpetuates itself in art.展开更多
As the greatest lyric poet of the 20th century,Yeats fully expresses his pursuit of eternal spiritual home in his poem“Sailing to Byzantium”.This paper analyzes the text and discusses how the poet strives to pursue ...As the greatest lyric poet of the 20th century,Yeats fully expresses his pursuit of eternal spiritual home in his poem“Sailing to Byzantium”.This paper analyzes the text and discusses how the poet strives to pursue his spiritual home,so as to deepen our readers’understanding of“eternity”theme in the poem.Seeking the Spiritual Home—Sailing to Byzantium.展开更多
Mr. Du Yuzhou, President of China National Textile and Apparel Council, is still steering the country’s flagship of textile industry. The wheelman has proactively been engaged in promoting the m ark etizatio n proces...Mr. Du Yuzhou, President of China National Textile and Apparel Council, is still steering the country’s flagship of textile industry. The wheelman has proactively been engaged in promoting the m ark etizatio n process with his open- minded, insightful thoughts and free trade philosophy.展开更多
Solar sail technology has been proposed and developed for space explorations with advantages of low launch cost,no-propellant consumption,and continuous thrust,which has great potentials in earth polar detection,inter...Solar sail technology has been proposed and developed for space explorations with advantages of low launch cost,no-propellant consumption,and continuous thrust,which has great potentials in earth polar detection,interstellar explorations and etc.The development of solar sail has made significant progress in structural design,manufacturing,materials,orbit transfer,and stability control in the past few decades,which makes meaningful contributions to astronomy,physics,and aerospace science.Technological breakthroughs of Solar Radiation Pressure(SRP)propulsion and interstellar transfer have been achieved in current solar sail missions.However,there are still many challenges and problems need to be solved.This paper attempts to summarize the research schemes and potential applications of solar sailing in space missions from the viewpoint of key technologies,so as to provide an overall perspective for researchers in this field.Analyses of the key technologies of solar sailing system design are provided.Finally,challenges and prospective development of solar sailing are discussed.展开更多
Shortest path routing protocol intends to minimize the total delay between every pair of destination node and source node. However, it is also well-known that shortest path routing suffers from uneven distribution of ...Shortest path routing protocol intends to minimize the total delay between every pair of destination node and source node. However, it is also well-known that shortest path routing suffers from uneven distribution of traffic load, especially in dense wireless networks. Recently, several new routing protocols are proposed in order to balance traffic load among nodes in a network. One of them is Circular Sailing Routing （CSR） which maps nodes on the surface of a sphere and select routes based on surface distances. CSR has been demonstrated with better load balance than shortest path routing via simulations. However, it is still open that what load distribution CSR can achieve. Therefore, in this paper, we theoretically analyze the traffic load distribution of CSR in a dense circular wireless network. Using the techniques developed by Hytti and Virtamo, we are able to derive the traffic load of any point inside the network. We then conduct extensive simulations to verify our theoretical results with grid and random networks.展开更多
【正】At the 60thanniversary of the China University of Petroleum,I just,on behalf of the China University of Petroleum(Beijing),extend my genuine congratulations and sincere gratitude to all our overseas and domestic...【正】At the 60thanniversary of the China University of Petroleum,I just,on behalf of the China University of Petroleum(Beijing),extend my genuine congratulations and sincere gratitude to all our overseas and domestic alumni,students,faculty and staff.For sixty years,from the start to nowadays,from a weak university to a strong one,it has cultivated over 20,0000 outstanding talents for petroleum industries in China.Students of the China University of Petroleum are sprinkling across the country,like brilliant bright pearls,throughout each corner of the world.At the 60thanniversary of the China University of Petroleum,the alma mater kindly informs each of you that the展开更多
The law of big fish swallowing little fish has expired when it comes to the era of new economy.What prevails nowadays in the sea of commerce is quick fish swallowing slow fish.In the Internet economy,small companies a...The law of big fish swallowing little fish has expired when it comes to the era of new economy.What prevails nowadays in the sea of commerce is quick fish swallowing slow fish.In the Internet economy,small companies are not destined to lose to giants,but slow ones are doomed to become prey of their quick counterparts. The swiftly rising Yongkang Group has made a breakthrough in dental treatment by translating the law into practice.It is called"Law of the Sea."‘Law of the Sea’展开更多
A considerable number of Chinese consumers are taking up the hobby of yachting, reflecting the nation's growing wealth A yacht is an extremely luxurious toy, costing perhaps millions of dollars. Despite this, yach...A considerable number of Chinese consumers are taking up the hobby of yachting, reflecting the nation's growing wealth A yacht is an extremely luxurious toy, costing perhaps millions of dollars. Despite this, yachting has caught on in China in the last 10 years. At the Taihu Lake in Wuxi City, Jiangsu Province, an American-invested yacht展开更多
Since the 1960s,an increasing interest in space propulsion methods(a)not-high-limited in energy(e.g.,electric rocket propulsion)and(b)involving no propellant(space sailing),has been advancing from theoretical,numerica...Since the 1960s,an increasing interest in space propulsion methods(a)not-high-limited in energy(e.g.,electric rocket propulsion)and(b)involving no propellant(space sailing),has been advancing from theoretical,numericalsimulation,and technological viewpoints.In particular,among the propulsion concepts of type(b),solar-photon sailing(SPS)has received greater and greater attention.展开更多
Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solv...Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solve the problem of contact between the sail membrane and the spacecraft under light pressure.Compared with the traditional TTM,it has a small size,light weight,high extension ratio,and simple structure.The anti-blossoming and self-unlocking structure of the proposed TTM was described.We aimed to simplify the TTM with a complex structure into a beam model with equal linear mass density,and the simulation results showed good consistency.The dynamic equation was derived based on the equivalent model,and the effects of different factors on the vibration characteristics of the TTM were analyzed.The performance parameters were optimized based on a multiobjective genetic algorithm,and prototype production and load experiments were conducted.The results show that the advantages of the new TTM can complete the deployment of large-scale solar sails,which is valuable for future deep space exploration.展开更多
基金supported by National Natural Science Foun-dation of China Grant (Grant No. 40705017)the Chinese Academy of Sciences Grant (Grant No. 2004-2-7)the Natural Science Foundation of Shandong Province Grant(Grant No. Q2007E03)
文摘Using data from automatic surface weather stations, buoys, lidar and Doppler, the diurnal variation and the three-dimensional structure of the sea breezes near the sailing sites of the Good Luck Beijing- 2006 Qingdao International Regatta from 18 to 31 August 2006 are analyzed. Results show that excluding rainy days and days affected by typhoon, the sea breezes occur nearly every day during this period. When Qingdao is located at the edge of the subtropical high at 500 hPa, the sea breeze is usually stronger, around 3-4 m s^-1. It starts at around 1100 to 1300 LST and lasts about 6 hours. The direction of the sea breeze tends to be southeasterly. When Qingdao is under the control of the subtropical high, the sea breeze is usually weaker, less than 2.5 m s^-1 throughout the day, and begins later, between 1300 and 1500 LST. In this case, the direction of the sea breeze is variable from easterly to southeasterly. Most sea breezes in Qingdao are very shallow, up to 300 meters deep. Strong sea breezes can reach 1.5 km in depth and can push as far as 100 km inland. If the Huanghai sea breeze moves inland and meets the sea breeze of the Jiaozhou Bay in the western part of Qingdao, the sea breeze will strengthen and form three boundaries due to the interaction of the two sea breezes.
文摘The election of Donald Trump as US President worries some of the people about reversal of globalization.As Trump talked a lot against globalization,they believe that his election is the beginning of the end of globalization.Furthermore,a series of events such as the Brexit and
文摘This paper attempts to analyze the symbolism that is embodied in"Sailing to Byzantium"and to further understand the spiritual freedom W. B. Yeats expressed in the poem. Studying the contrasts of the symbols and the eternity and holy spirit carried by Byzantium, we can understand Yeats' life philosophy, and finally reach his spiritual freedom which perpetuates itself in art.
文摘As the greatest lyric poet of the 20th century,Yeats fully expresses his pursuit of eternal spiritual home in his poem“Sailing to Byzantium”.This paper analyzes the text and discusses how the poet strives to pursue his spiritual home,so as to deepen our readers’understanding of“eternity”theme in the poem.Seeking the Spiritual Home—Sailing to Byzantium.
文摘Mr. Du Yuzhou, President of China National Textile and Apparel Council, is still steering the country’s flagship of textile industry. The wheelman has proactively been engaged in promoting the m ark etizatio n process with his open- minded, insightful thoughts and free trade philosophy.
基金co-supported by the Natural Science Foundation of China(No.51905527)China Scholarship Council(No.202104910450).
文摘Solar sail technology has been proposed and developed for space explorations with advantages of low launch cost,no-propellant consumption,and continuous thrust,which has great potentials in earth polar detection,interstellar explorations and etc.The development of solar sail has made significant progress in structural design,manufacturing,materials,orbit transfer,and stability control in the past few decades,which makes meaningful contributions to astronomy,physics,and aerospace science.Technological breakthroughs of Solar Radiation Pressure(SRP)propulsion and interstellar transfer have been achieved in current solar sail missions.However,there are still many challenges and problems need to be solved.This paper attempts to summarize the research schemes and potential applications of solar sailing in space missions from the viewpoint of key technologies,so as to provide an overall perspective for researchers in this field.Analyses of the key technologies of solar sailing system design are provided.Finally,challenges and prospective development of solar sailing are discussed.
基金supported by National Natural Science Foundation of China under No. 60903151Beijing Natural Science Foundation under No. 4122070+1 种基金Scientific Research Foundation for the Returned Overseas Chinese Scholars from State Education Ministry of ChinaUS National Science Foundation under Nos.CNS-0915331 and CNS-1050398
文摘Shortest path routing protocol intends to minimize the total delay between every pair of destination node and source node. However, it is also well-known that shortest path routing suffers from uneven distribution of traffic load, especially in dense wireless networks. Recently, several new routing protocols are proposed in order to balance traffic load among nodes in a network. One of them is Circular Sailing Routing （CSR） which maps nodes on the surface of a sphere and select routes based on surface distances. CSR has been demonstrated with better load balance than shortest path routing via simulations. However, it is still open that what load distribution CSR can achieve. Therefore, in this paper, we theoretically analyze the traffic load distribution of CSR in a dense circular wireless network. Using the techniques developed by Hytti and Virtamo, we are able to derive the traffic load of any point inside the network. We then conduct extensive simulations to verify our theoretical results with grid and random networks.
文摘【正】At the 60thanniversary of the China University of Petroleum,I just,on behalf of the China University of Petroleum(Beijing),extend my genuine congratulations and sincere gratitude to all our overseas and domestic alumni,students,faculty and staff.For sixty years,from the start to nowadays,from a weak university to a strong one,it has cultivated over 20,0000 outstanding talents for petroleum industries in China.Students of the China University of Petroleum are sprinkling across the country,like brilliant bright pearls,throughout each corner of the world.At the 60thanniversary of the China University of Petroleum,the alma mater kindly informs each of you that the
文摘The law of big fish swallowing little fish has expired when it comes to the era of new economy.What prevails nowadays in the sea of commerce is quick fish swallowing slow fish.In the Internet economy,small companies are not destined to lose to giants,but slow ones are doomed to become prey of their quick counterparts. The swiftly rising Yongkang Group has made a breakthrough in dental treatment by translating the law into practice.It is called"Law of the Sea."‘Law of the Sea’
文摘A considerable number of Chinese consumers are taking up the hobby of yachting, reflecting the nation's growing wealth A yacht is an extremely luxurious toy, costing perhaps millions of dollars. Despite this, yachting has caught on in China in the last 10 years. At the Taihu Lake in Wuxi City, Jiangsu Province, an American-invested yacht
文摘Since the 1960s,an increasing interest in space propulsion methods(a)not-high-limited in energy(e.g.,electric rocket propulsion)and(b)involving no propellant(space sailing),has been advancing from theoretical,numericalsimulation,and technological viewpoints.In particular,among the propulsion concepts of type(b),solar-photon sailing(SPS)has received greater and greater attention.
基金Supported by National Key R&D Program of China (Grant No.2018YFB1304600)National Natural Science Foundation of China (Grant No.51905527)+1 种基金CAS Interdisciplinary Innovation Team of China (Grant No.JCTD-2018-11)State Key Laboratory of Robotics Foundation of China (Grant No.Y91Z0303)。
文摘Large-scale solar sails can provide power to spacecraft for deep space exploration.A new type of telescopic tubular mast(TTM)driven by a bistable carbon fiber-reinforced polymer tube was designed in this study to solve the problem of contact between the sail membrane and the spacecraft under light pressure.Compared with the traditional TTM,it has a small size,light weight,high extension ratio,and simple structure.The anti-blossoming and self-unlocking structure of the proposed TTM was described.We aimed to simplify the TTM with a complex structure into a beam model with equal linear mass density,and the simulation results showed good consistency.The dynamic equation was derived based on the equivalent model,and the effects of different factors on the vibration characteristics of the TTM were analyzed.The performance parameters were optimized based on a multiobjective genetic algorithm,and prototype production and load experiments were conducted.The results show that the advantages of the new TTM can complete the deployment of large-scale solar sails,which is valuable for future deep space exploration.
