According to Bloomberg on November 12, China Petrochemical Corp., Asia’s biggest ref iner, agreed to buy a 30 percent stake in Galp Energia SGPS SA (GALP)’s Brazilian unit, its second invest- ment in offshore oil fi...According to Bloomberg on November 12, China Petrochemical Corp., Asia’s biggest ref iner, agreed to buy a 30 percent stake in Galp Energia SGPS SA (GALP)’s Brazilian unit, its second invest- ment in offshore oil fields in Latin America’s largest economy in as many years.展开更多
BP,the UK energy group,is planning to sell one of its biggest Chinese investments,by disposing of its 50percent stake in the SECCO petrochemicals plant near Shanghai.BP is the latest western oil company to curtail act...BP,the UK energy group,is planning to sell one of its biggest Chinese investments,by disposing of its 50percent stake in the SECCO petrochemicals plant near Shanghai.BP is the latest western oil company to curtail activity in China,as energy groups reel from low crude and petrochemical prices.China’s slow liberalization展开更多
How Egypt can attempt to revert back to its former glory OPTIMISTS who entertained thoughts that Egypt would revert to its former state of peace and tranquility after parliamentary elections must have been badly jolte...How Egypt can attempt to revert back to its former glory OPTIMISTS who entertained thoughts that Egypt would revert to its former state of peace and tranquility after parliamentary elections must have been badly jolted in early February.This is when a fairly innocuous event,a football match between two traditionally rival teams,ended with the death of over 70 people.How a sporting event can lead to such sectarian-motivated carnage underpins the deep-seated animosities unleashed after the January 25,2011 revo-展开更多
This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is t...This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.展开更多
先来看摘自一篇英语散文中的段落：地点哈瓦那,一个匈牙利人与倒卖雪茄的黑人烟贩子讨价还价。＂You’re crazy!＂cries the Hungarian in slightly accented English,taking one of the boxes from the trunk and waving it in Howard ...先来看摘自一篇英语散文中的段落：地点哈瓦那,一个匈牙利人与倒卖雪茄的黑人烟贩子讨价还价。＂You’re crazy!＂cries the Hungarian in slightly accented English,taking one of the boxes from the trunk and waving it in Howard Bingham’s face.＂These are Cohiba Esplendidos!The best in the world!You will pay one thousand dollars for a box like this in the States.＂展开更多
In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no...In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.展开更多
On February 19,2012,WalMart Stores,Inc.disclosed its additional investment in Yihaodian,a fast-growing electronic commerce website in China,making Walmart’s total ownership stake in Yihaodian to reach approximately 5...On February 19,2012,WalMart Stores,Inc.disclosed its additional investment in Yihaodian,a fast-growing electronic commerce website in China,making Walmart’s total ownership stake in Yihaodian to reach approximately 51%.It was Wal-Mart’s second investment for the purpose展开更多
文摘According to Bloomberg on November 12, China Petrochemical Corp., Asia’s biggest ref iner, agreed to buy a 30 percent stake in Galp Energia SGPS SA (GALP)’s Brazilian unit, its second invest- ment in offshore oil fields in Latin America’s largest economy in as many years.
文摘BP,the UK energy group,is planning to sell one of its biggest Chinese investments,by disposing of its 50percent stake in the SECCO petrochemicals plant near Shanghai.BP is the latest western oil company to curtail activity in China,as energy groups reel from low crude and petrochemical prices.China’s slow liberalization
文摘How Egypt can attempt to revert back to its former glory OPTIMISTS who entertained thoughts that Egypt would revert to its former state of peace and tranquility after parliamentary elections must have been badly jolted in early February.This is when a fairly innocuous event,a football match between two traditionally rival teams,ended with the death of over 70 people.How a sporting event can lead to such sectarian-motivated carnage underpins the deep-seated animosities unleashed after the January 25,2011 revo-
基金funded by Universiti Teknologi PETRONAS and grants(YUTP-PRG:015PBC-011).
文摘This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.
文摘先来看摘自一篇英语散文中的段落：地点哈瓦那,一个匈牙利人与倒卖雪茄的黑人烟贩子讨价还价。＂You’re crazy!＂cries the Hungarian in slightly accented English,taking one of the boxes from the trunk and waving it in Howard Bingham’s face.＂These are Cohiba Esplendidos!The best in the world!You will pay one thousand dollars for a box like this in the States.＂
基金the National Natural Science Foundation of China under Grant 61701059,Grant 61941114,and Grant 61831002,in part by the Fundamental Research Funds for the Central Universities of New TeachersProject,in part by the Chongqing Technological Innovation and Application Development Projects under Grant cstc2019jscx-msxm1322,and in part by the Eighteentg Open Foundation of State Key Lab of Integrated Services Networks of Xidian University under Grant ISN20-05.
文摘In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.
文摘On February 19,2012,WalMart Stores,Inc.disclosed its additional investment in Yihaodian,a fast-growing electronic commerce website in China,making Walmart’s total ownership stake in Yihaodian to reach approximately 51%.It was Wal-Mart’s second investment for the purpose
