Both the EU and China remain committed to safeguarding the multilateral trading system,which is in alignment with the bilateral and common interests of the world.
The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade ...The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade governance system has mainly referred to the multilateral trading system, with the General Agreement on Tariffs and Trade(GATT) and the World Trade Organization(WTO) serving as governance platforms.展开更多
On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported...On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.展开更多
After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since...After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since the end of World War Ⅱ was unable to make sense of the evolution and direction of this architecture.展开更多
In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exp...In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exposed the negative effect of economic coercion and isolation.Meanwhile,China’s commitment to openness,innovation,and shared prosperity offers a contrast,a testament to the enduring vitality of multilateralism and global integration.展开更多
Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi J...Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi Jinping has pointed out,multilateralism is the inevitable choice for addressing the world’s difficulties and challenges.1 However,various negative trends in international politics are undermining or impeding the effectiveness of multilateralism and aggravating the global governance deficit.Against this backdrop,it is essential to reassess the importance of multilateralism in global governance,identify the challenges it faces,and explore feasible pathways for collective action to advance global governance.展开更多
Due to high energy density,clean combustion products and abundant resources,natural gas hydrates(NGHs)have been regarded as an important clean energy source with the potential for large-scale development and utilizati...Due to high energy density,clean combustion products and abundant resources,natural gas hydrates(NGHs)have been regarded as an important clean energy source with the potential for large-scale development and utilization.However,pilot tests in NGHs show that their production rates are far below commercial needs.Multilateral well technology may lead to a solution to this problem because it can dramatically expand the drainage area of production wells.This paper presents the practical rate transient analysis for multilateral horizontal wells in NGHs.In developing solution to the diffusivity equation of multilateral horizontal wells in NGHs,the superposition principle and reciprocity are applied.We wrote the governing equation in cylindrical coordinates to describe the NGH flow process.We used the moving boundaries and dissociation coefficients to model the solid-to-gas transition process in hydrates.To obtain solutions for flow in hydrate reservoirs,we used Laplace transforms and the Stehfest numerical inversion method.Superposition principle and Gaussian elimination are applied to obtain the desired solution for multilateral horizontal wells.We validated our proposed model with a commercial numerical simulator.By performing sensitivity analyses,effects on production behavior of the number of branches,dissociation coefficient,radius of the region with dissociated hydrate,and dispersion ratio are determined.A synthetic case study is conducted to show the typical production behaviors.展开更多
Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third p...Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third plenary session,the 20th Central Commit tee of the Communist Par ty of China(CPC)stressed that it would“facilitate international cooperation in industrial and supply chains”.China is firmly committed to supporting and enhancing the multilateral trading system centered on the World Trade Organization(WTO)in order to ensure the smooth and stable operation of these chains.展开更多
China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic a...China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic and trade cooperation remains on a fast track,backed by concrete actions towards common modernisation.This collaboration reinforces solidarity across the Global South and contributes to greater stability and confidence in the global multilateral trading system.展开更多
AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tang...AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tangible outcomes,has demonstrated unique resilience and value.展开更多
On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based...On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based on principles of equality, mutual respect, and mutual benefit. They declared their commitment to continue strengthening friendly relations, deepening political trust, and expanding economic cooperation among the six nations.展开更多
The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround mu...The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround multilateral(WTO),regional,andbilateral(FTA)trade agreements.展开更多
This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficia...This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficial cooperation,and firmly upheld multilateralism,bringing tangible benefits to both peoples and making a significant contribution to global peace and development.展开更多
Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)informati...Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)information.This paper proposes a security position verification technique based on Multilateration(MLAT)to detect false signals,ensuring UAV safety and reliable airspace operations.First,the proposed method estimates the current position of the UAV by calculating the Time Difference of Arrival(TDOA),Time Sum of Arrival(TSOA),and Angle of Arrival(AOA)information.Then,this estimated position is compared with the ADS-B message to eliminate false UAV signals.Furthermore,a localization model based on TDOA/TSOA/AOA is established by utilizing reliable reference sources for base station time synchronization.Additionally,an improved Chan-Taylor algorithm is developed,incorporating the Constrained Weighted Least Squares(CWLS)method to initialize UAV position calculations.Finally,a false signal detection method is proposed to distinguish between true and false positioning targets.Numerical simulation results indicate that,at a positioning error threshold of 150 m,the improved Chan-Taylor algorithm based on TDOA/TSOA/AOA achieves 100%accuracy coverage,significantly enhancing localization precision.And the proposed false signal detection method achieves a detection accuracy rate of at least 90%within a 50-meter error range.展开更多
In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were appli...In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were applied to study optimization design of herringbone multilateral well.According to the characteristics of herringbone multilateral well,by using pressure superposition and mirror image reflection theory,the coupled model of herringbone multilateral well was developed on the basis of a three-dimensional pseudo-pressure distribution model for horizontal wells.The model was formulated in consideration of friction loss,acceleration loss of the wellbore and mixed loss at the confluence of main wellbore and branched one.After mathematical simulation on productivity of the herringbone multilateral well with the coupled model,the effects of well configuration on productivity were analyzed.The results show that lateral number is the most important factor,length of main wellbore and length of branched wellbore are the secondary ones,angle between main and branched one has the least influence.展开更多
Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its...Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its low cost and high accuracy. Unfortunately, ADS-B is prone to cyber-attacks. To verify the ADS-B positioning data of aircraft, multilateration(MLAT)techniques that use Time Differences of Arrivals(TDoAs) have been proposed. MLAT exhibits low accuracy in determining aircraft positions. Recently, a novel technique using a theoretically calculated TDoA fingerprint map has been proposed. This technique is less dependent on the geometry of sensor deployment and achieves better accuracy than MLAT. However, the accuracy of the existing technique is not sufficiently precise for determining aircraft positions and requires a long computation time. In contrast, this paper presents a reliable surveillance framework using an Actual TDoA-Based Augmentation System(ATBAS). It uses historically recorded real-data from the OpenSky network to train our TDoA fingerprint grid network. Our results show that the accuracy of the proposed ATBAS framework in determining the aircraft positions is significantly better than those of the MLAT and expected TDoA techniques by 56.93% and 48.86%, respectively. Additionally, the proposed framework reduced the computation time by 77% compared with the expected TDoA technique.展开更多
Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,dr...Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,drilling a multilateral well does not always increase the flow rate when compared to two single-horizontal wells due to competition in production inside the mother-bore.Here,a holistic approach is proposed to find the optimum balance between single and multilateral wells in an offshore oil development.In so doing,the integrated approach finds the highest Net Present Value(NPV)configuration of the field considering drilling,subsurface,production and financial analysis.The model employs stochastic perturbation and Markov Chain Monte-Carlo methods to solve the global maximising-NPV problem.In addition,a combination of Mixed-Integer Linear Programming(MILP),an improved Dijkstra algorithm and a Levenberg-Marquardt optimiser is proposed to solve the rate allocation problem.With the outcome from this analysis,the model suggests the optimum development including number of multilateral and single horizontal wells that would result in the highest NPV.The results demonstrate the potential for modelling to find the optimal use of petroleum facilities and to assist with planning and decision making.展开更多
The article reviews the stable logic analysis model of complex systems or steady multilateral systems with two non-compatibility relations. Energy concept in Physics is introduced to the multilateral systems and used ...The article reviews the stable logic analysis model of complex systems or steady multilateral systems with two non-compatibility relations. Energy concept in Physics is introduced to the multilateral systems and used to deal with the multilateral system diseases. By using mathematical reasoning, it is demonstrated that the treatment principle: “Virtual disease is to fill his mother but real disease is to rush down his son” and “Strong inhibition of the same time, support the weak” which due to the “Yin Yang Wu Xing” Theory in Traditional Chinese Medicine (TCM).展开更多
文摘Both the EU and China remain committed to safeguarding the multilateral trading system,which is in alignment with the bilateral and common interests of the world.
文摘The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade governance system has mainly referred to the multilateral trading system, with the General Agreement on Tariffs and Trade(GATT) and the World Trade Organization(WTO) serving as governance platforms.
文摘On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.
文摘After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since the end of World War Ⅱ was unable to make sense of the evolution and direction of this architecture.
文摘In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exposed the negative effect of economic coercion and isolation.Meanwhile,China’s commitment to openness,innovation,and shared prosperity offers a contrast,a testament to the enduring vitality of multilateralism and global integration.
文摘Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi Jinping has pointed out,multilateralism is the inevitable choice for addressing the world’s difficulties and challenges.1 However,various negative trends in international politics are undermining or impeding the effectiveness of multilateralism and aggravating the global governance deficit.Against this backdrop,it is essential to reassess the importance of multilateralism in global governance,identify the challenges it faces,and explore feasible pathways for collective action to advance global governance.
基金This work received funding support from National Natural Science Foundation of China(12202042),Highend Foreign Expert Introduction Program(G2023105006L)China Postdoctoral Science Foundations(2021M700391)Fundamental Research Funds for the Central Universities(QNXM20220011,FRFTP-22-119A1,FRF-IDRY-22-001)。
文摘Due to high energy density,clean combustion products and abundant resources,natural gas hydrates(NGHs)have been regarded as an important clean energy source with the potential for large-scale development and utilization.However,pilot tests in NGHs show that their production rates are far below commercial needs.Multilateral well technology may lead to a solution to this problem because it can dramatically expand the drainage area of production wells.This paper presents the practical rate transient analysis for multilateral horizontal wells in NGHs.In developing solution to the diffusivity equation of multilateral horizontal wells in NGHs,the superposition principle and reciprocity are applied.We wrote the governing equation in cylindrical coordinates to describe the NGH flow process.We used the moving boundaries and dissociation coefficients to model the solid-to-gas transition process in hydrates.To obtain solutions for flow in hydrate reservoirs,we used Laplace transforms and the Stehfest numerical inversion method.Superposition principle and Gaussian elimination are applied to obtain the desired solution for multilateral horizontal wells.We validated our proposed model with a commercial numerical simulator.By performing sensitivity analyses,effects on production behavior of the number of branches,dissociation coefficient,radius of the region with dissociated hydrate,and dispersion ratio are determined.A synthetic case study is conducted to show the typical production behaviors.
文摘Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third plenary session,the 20th Central Commit tee of the Communist Par ty of China(CPC)stressed that it would“facilitate international cooperation in industrial and supply chains”.China is firmly committed to supporting and enhancing the multilateral trading system centered on the World Trade Organization(WTO)in order to ensure the smooth and stable operation of these chains.
文摘China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic and trade cooperation remains on a fast track,backed by concrete actions towards common modernisation.This collaboration reinforces solidarity across the Global South and contributes to greater stability and confidence in the global multilateral trading system.
文摘AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tangible outcomes,has demonstrated unique resilience and value.
文摘On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based on principles of equality, mutual respect, and mutual benefit. They declared their commitment to continue strengthening friendly relations, deepening political trust, and expanding economic cooperation among the six nations.
文摘The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround multilateral(WTO),regional,andbilateral(FTA)trade agreements.
文摘This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficial cooperation,and firmly upheld multilateralism,bringing tangible benefits to both peoples and making a significant contribution to global peace and development.
基金supported by the National Natural Science Foundation of China(Nos.U2441250,62301380,and 62231027)Natural Science Basic Research Program of Shaanxi,China(2024JC-JCQN-63)+3 种基金the Key Research and Development Program of Shaanxi,China(No.2023-YBGY-249)the Guangxi Key Research and Development Program,China(No.2022AB46002)the China Postdoctoral Science Foundation(No.2022M722504 and 2024T170696)the Innovation Capability Support Program of Shaanxi,China(No.2024RS-CXTD-01).
文摘Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)information.This paper proposes a security position verification technique based on Multilateration(MLAT)to detect false signals,ensuring UAV safety and reliable airspace operations.First,the proposed method estimates the current position of the UAV by calculating the Time Difference of Arrival(TDOA),Time Sum of Arrival(TSOA),and Angle of Arrival(AOA)information.Then,this estimated position is compared with the ADS-B message to eliminate false UAV signals.Furthermore,a localization model based on TDOA/TSOA/AOA is established by utilizing reliable reference sources for base station time synchronization.Additionally,an improved Chan-Taylor algorithm is developed,incorporating the Constrained Weighted Least Squares(CWLS)method to initialize UAV position calculations.Finally,a false signal detection method is proposed to distinguish between true and false positioning targets.Numerical simulation results indicate that,at a positioning error threshold of 150 m,the improved Chan-Taylor algorithm based on TDOA/TSOA/AOA achieves 100%accuracy coverage,significantly enhancing localization precision.And the proposed false signal detection method achieves a detection accuracy rate of at least 90%within a 50-meter error range.
基金Project(12521044) supported by Scientific and Technological Research Program of Heilongjiang Provincial Education Department,China
文摘In order to accurately predict the productivity of herringbone multilateral well,a new productivity prediction model was founded.And based on this model,orthogonal test and multiple factor variance analysis were applied to study optimization design of herringbone multilateral well.According to the characteristics of herringbone multilateral well,by using pressure superposition and mirror image reflection theory,the coupled model of herringbone multilateral well was developed on the basis of a three-dimensional pseudo-pressure distribution model for horizontal wells.The model was formulated in consideration of friction loss,acceleration loss of the wellbore and mixed loss at the confluence of main wellbore and branched one.After mathematical simulation on productivity of the herringbone multilateral well with the coupled model,the effects of well configuration on productivity were analyzed.The results show that lateral number is the most important factor,length of main wellbore and length of branched wellbore are the secondary ones,angle between main and branched one has the least influence.
文摘Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its low cost and high accuracy. Unfortunately, ADS-B is prone to cyber-attacks. To verify the ADS-B positioning data of aircraft, multilateration(MLAT)techniques that use Time Differences of Arrivals(TDoAs) have been proposed. MLAT exhibits low accuracy in determining aircraft positions. Recently, a novel technique using a theoretically calculated TDoA fingerprint map has been proposed. This technique is less dependent on the geometry of sensor deployment and achieves better accuracy than MLAT. However, the accuracy of the existing technique is not sufficiently precise for determining aircraft positions and requires a long computation time. In contrast, this paper presents a reliable surveillance framework using an Actual TDoA-Based Augmentation System(ATBAS). It uses historically recorded real-data from the OpenSky network to train our TDoA fingerprint grid network. Our results show that the accuracy of the proposed ATBAS framework in determining the aircraft positions is significantly better than those of the MLAT and expected TDoA techniques by 56.93% and 48.86%, respectively. Additionally, the proposed framework reduced the computation time by 77% compared with the expected TDoA technique.
文摘Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,drilling a multilateral well does not always increase the flow rate when compared to two single-horizontal wells due to competition in production inside the mother-bore.Here,a holistic approach is proposed to find the optimum balance between single and multilateral wells in an offshore oil development.In so doing,the integrated approach finds the highest Net Present Value(NPV)configuration of the field considering drilling,subsurface,production and financial analysis.The model employs stochastic perturbation and Markov Chain Monte-Carlo methods to solve the global maximising-NPV problem.In addition,a combination of Mixed-Integer Linear Programming(MILP),an improved Dijkstra algorithm and a Levenberg-Marquardt optimiser is proposed to solve the rate allocation problem.With the outcome from this analysis,the model suggests the optimum development including number of multilateral and single horizontal wells that would result in the highest NPV.The results demonstrate the potential for modelling to find the optimal use of petroleum facilities and to assist with planning and decision making.
文摘The article reviews the stable logic analysis model of complex systems or steady multilateral systems with two non-compatibility relations. Energy concept in Physics is introduced to the multilateral systems and used to deal with the multilateral system diseases. By using mathematical reasoning, it is demonstrated that the treatment principle: “Virtual disease is to fill his mother but real disease is to rush down his son” and “Strong inhibition of the same time, support the weak” which due to the “Yin Yang Wu Xing” Theory in Traditional Chinese Medicine (TCM).
