The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by shor...The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by short arcs and observation errors typically causes significant errors in the estimated ranges and thus unsatisfactory IOD.This paper presents a critical analysis of the ill-conditioned problem using the Gooding algorithm and proposes several techniques to improve it.On the basis of multiple observations,a least-squares method is proposed to solve the ranges at the first and last epochs.For the short-arc case,the ridge estimation technique is applied to mitigate the ill-conditioned problem.To determine whether an orbit is eccentric,a procedure to assess orbit eccentricity is developed via the range-search method,which aims to provide reasonably accurate initial ranges to the Gooding algorithm.Finally,an eccentricity-constraint technique for the Gooding algorithm is proposed for cases where the orbit is determined to be nearly circular.The performances of these techniques on space-based simulation data are assessed,and an improved Gooding algorithm(I-Gooding)suitable for various observation conditions is proposed.The I-Gooding algorithm is subsequently applied to process actual ground-based observations.The results show that its accuracy in estimating the semimajor axis is 47%higher than that afforded by the standard Gooding algorithm.展开更多
An initial orbit determination (IOD) solution from angles-only observations of a single short orbit arc is often required for applications such as tracklet association and fast reacquisition of a newly detected space ...An initial orbit determination (IOD) solution from angles-only observations of a single short orbit arc is often required for applications such as tracklet association and fast reacquisition of a newly detected space object. Modern optical observations can collect tens or even hundreds of data points over a short arc, thus enabling a large number of IOD solutions to be determined when using an IOD algorithm of 3 lines of sight (3-LOSs), such as the Gooding algorithm. It is necessary but difficult to find an optimal solution from a solution pool, particularly in the case of too short arc (TSA). Another issue in using 3-LOSs IOD methods is the neglect of perturbation effects on the observations. That is, 3-LOSs IOD methods are developed in the 2-body frame, but the observations are perturbed. Thus, the IOD solutions may have additional errors if the observations are not corrected for perturbation effects. In this study, we investigate the distribution of the semi-major axis and eccentricity of IOD solutions in a pool and find that choosing the solution with the maximum kernel density in the distribution is a much better way to determine the final solution from the pool. We also propose a technique to correct J2 secular effects on observed angle data. We use the Gooding algorithm as the basic 3-LOSs IOD algorithm to demonstrate the effectiveness of the proposed techniques in improving the IOD accuracy in the cases of short-arc ground-based observations and space-based simulation data.展开更多
As China and Laos mark the 65th anniversary of their diplomatic relations,the two socialist neighbors stand at a new historical starting point.From revolutionary comrades-in-arms to comprehensive strategic partners,Ch...As China and Laos mark the 65th anniversary of their diplomatic relations,the two socialist neighbors stand at a new historical starting point.From revolutionary comrades-in-arms to comprehensive strategic partners,China and Laos have steadily deepened their bond as"good neighbors,good friends,good comrades,and good partners."展开更多
Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official d...Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official data showed.Data released on 10 March by the General Administration of Customs revealed that total goods trade value had reached 7.73 trillion yuan(about$1.12 trillion)during this period.展开更多
Hainan’s special customs operations are expected to significantly reduce the institutional costs of foreign goods flowing into Hainan,enabling the island to function as a gateway for global goods.DAVID Adrian Janke,a...Hainan’s special customs operations are expected to significantly reduce the institutional costs of foreign goods flowing into Hainan,enabling the island to function as a gateway for global goods.DAVID Adrian Janke,a British citizen operating a translation company in Haikou,capital of Hainan Province in south China,witnessed surging orders as special customs operations got underway in the island province on December 18.展开更多
This study empirically examines how land finance in destination and origin cities affects willingness to engage in labor mobility and explores the underlying mechanisms.Using a two-way fixed effects model,we match mac...This study empirically examines how land finance in destination and origin cities affects willingness to engage in labor mobility and explores the underlying mechanisms.Using a two-way fixed effects model,we match macro data from 287 prefecture-level cities in China from 2000 to 2020 with data from the 2018 China Migrant Dynamic Survey(CMDS).The results are as follows:First,land finance in destination cities inhibits labor mobility willingness,while land finance in origin cities and labor mobility willingness have a U-shaped relationship,decreasing initially and then increasing.Second,local governments’dependence on land finance increases local housing prices and suppresses investment in non-economic public goods in the administrative area,thereby inhibiting labor mobility willingness;however,this also increases investment in economic public goods,attracting labor mobility willingness.Third,labor force age weakens the impact of land finance in origin cities on labor mobility willingness;however,age does not affect the impact of land finance in destination cities on labor mobility willingness.Fourth,land finance increases laborers’willingness to settle.展开更多
The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to...The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to analyze the methods of its English-to-Chinese subtitle translation by considering social,cultural,and historic backgrounds between China and America.After data collection and case analysis,the study found that:(1)Five major translation methods are adopted in the subtitle translation of The Good Wife.They are free translation,variation,literal translation,addition,and omission.Among them,free translation is the most frequently used,while omission is used least.(2)The subtitle translation of films and TV series is limited by time and space restrictions,social-cultural differences,and other factors.When translating,translators should try to use humorous words,euphemism,intonation,and other ways,and combine different methods such as literal translation,free translation,variation,addition,omission,and other methods to seek equivalence both in the meaning and function of subtitles under the guidance of Functional Equivalence Theory.展开更多
For ordinary tourists, simpler entry and exit procedures and a broader range of duty-free goods in Hainan create a better travel and shopping experience.For China’s earnest endeavor to deepen reform and opening-up, i...For ordinary tourists, simpler entry and exit procedures and a broader range of duty-free goods in Hainan create a better travel and shopping experience.For China’s earnest endeavor to deepen reform and opening-up, implementation of the special customs operations policy in Hainan represents a significant step forward. For businesses in Malaysia and other ASEAN member states, especially export-oriented small and medium-sized enterprises (SMEs), Hainan serves as a“transit hub” for accessing the Chinese market and even other Asian markets.展开更多
The Global Governance Initiative(GGI)is another important public good that China has provided for the international community,following the Global Development Initiative,the Global Security Initiative,and the Global C...The Global Governance Initiative(GGI)is another important public good that China has provided for the international community,following the Global Development Initiative,the Global Security Initiative,and the Global Civilization Initiative.As a sub-field of global governance,global climate governance has hitherto progressed slowly,exhibiting growing deficits in discourse,institutions,and actions.The governance paradigm is in desperate need of revamping,especially under the guidance of an innovative initiative.At the conceptual level,the GGI has gone beyond the Western governance discourse by outlining the institutional starting point,foundations of legitimacy,action orientations,ultimate goals,and practical support for good global climate governance through its five core concepts.At the practical level,the spillover effects of China's achievements in climate governance and the collective rise of the Global South have created favorable conditions,domestically and internationally,for the GGI to lead the way forward toward good global climate governance.However,the fact that the international political and economic order remains unjust and inequitable indicates that this will inevitably be a long-term process replete with rivalries in the pursuit of breakthroughs.展开更多
The year 2025 marked the 80th anniversary of the victory in the World Anti-Fascist War as well as the 10th anniversary of the Lancang-Mekong Cooperation (LMC) mechanism.Over the past decade, the six LMC countries have...The year 2025 marked the 80th anniversary of the victory in the World Anti-Fascist War as well as the 10th anniversary of the Lancang-Mekong Cooperation (LMC) mechanism.Over the past decade, the six LMC countries have maintained good-neighborly friendship, focused on development-oriented and pragmatic cooperation, and promoted inclusive, peoplecentered outcomes.展开更多
After the end of World War II,African countries successively gained independence and ushered in a golden age of economic development.Through the strategies of primary product exports,transitional economic policies and...After the end of World War II,African countries successively gained independence and ushered in a golden age of economic development.Through the strategies of primary product exports,transitional economic policies and import substitution development,their economic growth accelerated significantly.However,due to the limitations of these strategies,the structural problem of Africa being an exporter of cheap industrial raw materials and an importer of manufactured goods remained unresolved.展开更多
The dedicated freight channel at the Youyiguan Border Gate in south China’s Guangxi Zhuang Autonomous Region buzzes with activity as trucks loaded with export goods move steadily through customs.Thanks to a system up...The dedicated freight channel at the Youyiguan Border Gate in south China’s Guangxi Zhuang Autonomous Region buzzes with activity as trucks loaded with export goods move steadily through customs.Thanks to a system upgraded at the start of 2026,clearance personnel at this China-Vietnam crossing simply place an order online,and the entire process is handled almost instantly via an intelligent platform.Adding to the efficiency,the border gate also features dedicated lanes that support driverless container trucks.展开更多
The Hainan Free Trade Port(FTP),with the launching of island-wide special customs operations,is allowing greater convenience for overseas goods to enter the island,trying to build it into an efficient hub connecting C...The Hainan Free Trade Port(FTP),with the launching of island-wide special customs operations,is allowing greater convenience for overseas goods to enter the island,trying to build it into an efficient hub connecting China with the rest of the world.Its core appeal no longer relies solely on policy incentives but has shifted toward transparent and predictable institutional guarantees which provide stable expectations for global investors.展开更多
Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,go...Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,good damping,high castability,high capacity of hydrogen storage。展开更多
基金supported by the Special Fund of the Hubei Luojia Laboratory(Grant No.230100003)the Chongqing Municipal Natural Science Foundation of the General Program(Grant No.CSTB2022NSCQ-MSX1093)the Science and Technology Research Program of the Chongqing Municipal Education Commission(Grant No.KJQN202200701)。
文摘The accuracy of angles-only initial orbit determination(IOD)is significantly compromised when only a short-arc orbit is observed.The ill-conditioned problem in matrices due to weak geometric constraints caused by short arcs and observation errors typically causes significant errors in the estimated ranges and thus unsatisfactory IOD.This paper presents a critical analysis of the ill-conditioned problem using the Gooding algorithm and proposes several techniques to improve it.On the basis of multiple observations,a least-squares method is proposed to solve the ranges at the first and last epochs.For the short-arc case,the ridge estimation technique is applied to mitigate the ill-conditioned problem.To determine whether an orbit is eccentric,a procedure to assess orbit eccentricity is developed via the range-search method,which aims to provide reasonably accurate initial ranges to the Gooding algorithm.Finally,an eccentricity-constraint technique for the Gooding algorithm is proposed for cases where the orbit is determined to be nearly circular.The performances of these techniques on space-based simulation data are assessed,and an improved Gooding algorithm(I-Gooding)suitable for various observation conditions is proposed.The I-Gooding algorithm is subsequently applied to process actual ground-based observations.The results show that its accuracy in estimating the semimajor axis is 47%higher than that afforded by the standard Gooding algorithm.
基金supported by the National Natural Science Foundation of China(grant nos.12103035 and 12373083)the Fundamental Research Funds for the Central Universities(grant no.2042023gf0007).
文摘An initial orbit determination (IOD) solution from angles-only observations of a single short orbit arc is often required for applications such as tracklet association and fast reacquisition of a newly detected space object. Modern optical observations can collect tens or even hundreds of data points over a short arc, thus enabling a large number of IOD solutions to be determined when using an IOD algorithm of 3 lines of sight (3-LOSs), such as the Gooding algorithm. It is necessary but difficult to find an optimal solution from a solution pool, particularly in the case of too short arc (TSA). Another issue in using 3-LOSs IOD methods is the neglect of perturbation effects on the observations. That is, 3-LOSs IOD methods are developed in the 2-body frame, but the observations are perturbed. Thus, the IOD solutions may have additional errors if the observations are not corrected for perturbation effects. In this study, we investigate the distribution of the semi-major axis and eccentricity of IOD solutions in a pool and find that choosing the solution with the maximum kernel density in the distribution is a much better way to determine the final solution from the pool. We also propose a technique to correct J2 secular effects on observed angle data. We use the Gooding algorithm as the basic 3-LOSs IOD algorithm to demonstrate the effectiveness of the proposed techniques in improving the IOD accuracy in the cases of short-arc ground-based observations and space-based simulation data.
文摘As China and Laos mark the 65th anniversary of their diplomatic relations,the two socialist neighbors stand at a new historical starting point.From revolutionary comrades-in-arms to comprehensive strategic partners,China and Laos have steadily deepened their bond as"good neighbors,good friends,good comrades,and good partners."
文摘Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official data showed.Data released on 10 March by the General Administration of Customs revealed that total goods trade value had reached 7.73 trillion yuan(about$1.12 trillion)during this period.
文摘Hainan’s special customs operations are expected to significantly reduce the institutional costs of foreign goods flowing into Hainan,enabling the island to function as a gateway for global goods.DAVID Adrian Janke,a British citizen operating a translation company in Haikou,capital of Hainan Province in south China,witnessed surging orders as special customs operations got underway in the island province on December 18.
基金funded by Major Project of the National Social Science Fund of China“Theory,Methods and Chinese Practices of National Welfare Accounting”[Grant No.22&ZD165]Key Project of the National Social Science Fund of China“Theoretical and Practical Research on the Compilation of Chinese Productivity Accounts”[Grant No.21AZD122].
文摘This study empirically examines how land finance in destination and origin cities affects willingness to engage in labor mobility and explores the underlying mechanisms.Using a two-way fixed effects model,we match macro data from 287 prefecture-level cities in China from 2000 to 2020 with data from the 2018 China Migrant Dynamic Survey(CMDS).The results are as follows:First,land finance in destination cities inhibits labor mobility willingness,while land finance in origin cities and labor mobility willingness have a U-shaped relationship,decreasing initially and then increasing.Second,local governments’dependence on land finance increases local housing prices and suppresses investment in non-economic public goods in the administrative area,thereby inhibiting labor mobility willingness;however,this also increases investment in economic public goods,attracting labor mobility willingness.Third,labor force age weakens the impact of land finance in origin cities on labor mobility willingness;however,age does not affect the impact of land finance in destination cities on labor mobility willingness.Fourth,land finance increases laborers’willingness to settle.
文摘The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to analyze the methods of its English-to-Chinese subtitle translation by considering social,cultural,and historic backgrounds between China and America.After data collection and case analysis,the study found that:(1)Five major translation methods are adopted in the subtitle translation of The Good Wife.They are free translation,variation,literal translation,addition,and omission.Among them,free translation is the most frequently used,while omission is used least.(2)The subtitle translation of films and TV series is limited by time and space restrictions,social-cultural differences,and other factors.When translating,translators should try to use humorous words,euphemism,intonation,and other ways,and combine different methods such as literal translation,free translation,variation,addition,omission,and other methods to seek equivalence both in the meaning and function of subtitles under the guidance of Functional Equivalence Theory.
文摘For ordinary tourists, simpler entry and exit procedures and a broader range of duty-free goods in Hainan create a better travel and shopping experience.For China’s earnest endeavor to deepen reform and opening-up, implementation of the special customs operations policy in Hainan represents a significant step forward. For businesses in Malaysia and other ASEAN member states, especially export-oriented small and medium-sized enterprises (SMEs), Hainan serves as a“transit hub” for accessing the Chinese market and even other Asian markets.
基金2024 Shaanxi Provincial Social Science Fund Annual Project titled"Research on Chinese Modernization from the Perspective of Overseas Studies on the Communist Party of China"(Project Number:2024B002)a 2024 key project of Xi'an Jiaotong University for studying and expounding Xi Jinping Thought on Culture titled"Research on the World Implications of a New Model for Human Advancement"(Project Number:SKZX2024003)funded by the"Top Young Talents Project"(TZ0275)of Shaanxi Province's second batch of"Special Support Program for High-Level Talents"(Philosophy,Social Sciences,Culture,and Arts).
文摘The Global Governance Initiative(GGI)is another important public good that China has provided for the international community,following the Global Development Initiative,the Global Security Initiative,and the Global Civilization Initiative.As a sub-field of global governance,global climate governance has hitherto progressed slowly,exhibiting growing deficits in discourse,institutions,and actions.The governance paradigm is in desperate need of revamping,especially under the guidance of an innovative initiative.At the conceptual level,the GGI has gone beyond the Western governance discourse by outlining the institutional starting point,foundations of legitimacy,action orientations,ultimate goals,and practical support for good global climate governance through its five core concepts.At the practical level,the spillover effects of China's achievements in climate governance and the collective rise of the Global South have created favorable conditions,domestically and internationally,for the GGI to lead the way forward toward good global climate governance.However,the fact that the international political and economic order remains unjust and inequitable indicates that this will inevitably be a long-term process replete with rivalries in the pursuit of breakthroughs.
文摘The year 2025 marked the 80th anniversary of the victory in the World Anti-Fascist War as well as the 10th anniversary of the Lancang-Mekong Cooperation (LMC) mechanism.Over the past decade, the six LMC countries have maintained good-neighborly friendship, focused on development-oriented and pragmatic cooperation, and promoted inclusive, peoplecentered outcomes.
文摘After the end of World War II,African countries successively gained independence and ushered in a golden age of economic development.Through the strategies of primary product exports,transitional economic policies and import substitution development,their economic growth accelerated significantly.However,due to the limitations of these strategies,the structural problem of Africa being an exporter of cheap industrial raw materials and an importer of manufactured goods remained unresolved.
文摘The dedicated freight channel at the Youyiguan Border Gate in south China’s Guangxi Zhuang Autonomous Region buzzes with activity as trucks loaded with export goods move steadily through customs.Thanks to a system upgraded at the start of 2026,clearance personnel at this China-Vietnam crossing simply place an order online,and the entire process is handled almost instantly via an intelligent platform.Adding to the efficiency,the border gate also features dedicated lanes that support driverless container trucks.
文摘The Hainan Free Trade Port(FTP),with the launching of island-wide special customs operations,is allowing greater convenience for overseas goods to enter the island,trying to build it into an efficient hub connecting China with the rest of the world.Its core appeal no longer relies solely on policy incentives but has shifted toward transparent and predictable institutional guarantees which provide stable expectations for global investors.
文摘Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,good damping,high castability,high capacity of hydrogen storage。
