We report the detection of type-B quasi-periodic oscillation(QPO)of the black hole X-ray binary Swift J1728.9-3613 observed by NICER during the 2019 outburst.A type-B QPO was observed for the first two days and it dis...We report the detection of type-B quasi-periodic oscillation(QPO)of the black hole X-ray binary Swift J1728.9-3613 observed by NICER during the 2019 outburst.A type-B QPO was observed for the first two days and it disappeared as flux increased,but again appeared at∼7.70 Hz when flux was dramatically decreased.The source was found in the soft intermediate state during these observations.We further studied the energy dependence of the QPO.We found that QPO was observed only for a higher energy range implying that the origin of QPO is possibly due to the corona emitting higher energy photons by the inverse Compton process.The variation of spectral parameters can be explained with the disk truncation model.The fractional rms was found to be monotonically increased with energy.The phase lag spectrum followed the“U-shaped”curve.The rms and phase lag spectrum are modeled and explained with the single-component Comptonization model vkompthdk.展开更多
The Swift effect of Mg alloy is sensitive to initial texture.However,dislocation slip is the main deformation mechanism during torsion of Mg alloy.The underlying relation of Swift effect and dislocation slip is still ...The Swift effect of Mg alloy is sensitive to initial texture.However,dislocation slip is the main deformation mechanism during torsion of Mg alloy.The underlying relation of Swift effect and dislocation slip is still not clarified.The effect of stress state and pre-straining on Swift effect was studied experimentally during free-end torsion for an extruded AZ31 alloy.The free-end torsion was performed with axial tension and compression stress which is lower than yield stress.It is found that the transition of axial deformation from contraction to elongation occurs when the axial stress changes from negative to positive.The pre-dislocations introduced by pre-tension promote axial shortening during torsion.While the pre-twins introduced by pre-compression are inhibition of axial shortening.The change of axial deformation is attributed to competition between twinning and prismatic slip.The axial shortening of extruded Mg alloy is generated by tensile twinning leading to c-axis strain.In contrast,the axial elongation can be generated by the activation of prismatic slip.The magnitude of axial strain generated by twinning is larger than that by prismatic slip.Moreover,the occurrence of detwinning results in axial elongation at low shear strain.展开更多
Mainstream industrial policy research cannot fully explain how government interventions have helped China’s mobile communications industry catch up with and overtake those of advanced nations.China’s mobile communic...Mainstream industrial policy research cannot fully explain how government interventions have helped China’s mobile communications industry catch up with and overtake those of advanced nations.China’s mobile communications industry made breakthroughs in 3G,caught up with advanced nations in 4G,and gained a leadership position in 5G due to the implementation and improvement of a strategy of industrial competition that accommodates mainstream standards and prioritizes the mid-band spectrum based on the integrated“technology,standard and industry”deployment system and swift decision-making.The introduction of a perspective of a strategy of industrial competition may supplement industrial policy research in the following ways:First,when the concerted actions of numerous innovators are important for industrial competition performance,an effective strategy of industrial competition can be devised and overall coordinated by the government provided that is compatible with the catch-up development of emerging technological industries.Second,an industrial policy becomes effective when it is complementary with the strategic factors for long-term industrial performance such as the strategy of industrial competition and avoids serious disruptions to market-based mechanisms.展开更多
跨境金融通信对于现代金融业务的开展极为重要.环球银行金融电信协会(SWIFT)是跨境金融通信服务的主要提供者.现阶段,报文传输是 SWIFT 系统的主要业务,确保报文传输安全、准确、高效,是 SWIFT 系统的重要目标.但现阶段基于中心架构思想...跨境金融通信对于现代金融业务的开展极为重要.环球银行金融电信协会(SWIFT)是跨境金融通信服务的主要提供者.现阶段,报文传输是 SWIFT 系统的主要业务,确保报文传输安全、准确、高效,是 SWIFT 系统的重要目标.但现阶段基于中心架构思想的 SWIFT 系统安全风险突出,传输效率低,成本较高.基于许可链分布式共识机制,提出 BCSWIFT 系统,对现有的 SWIFT 系统进行优化.首先,将 SWIFT 系统的传输网络划分为主网络层和附加网络层;其次,提出了基于双层网络结构的共识算法;第三,介绍了 BCSWIFT 系统的报文交互和传输机制;第四,出于金融业务数据商业保密考虑,提出了一种面向 BCSWIFT 系统的隐私保护机制;第五,对 BCSWIFT 系统的安全性进行了分析.以优化 SWIFT 系统的报文传输业务为例,阐释了基于许可链的跨境金融通信的基本机理,为确保跨境支付、清算、结算的安全、高效、准确和低成本化运作提供了新的思路,也为区块链技术大规模商业应用提供了重要参照.展开更多
文摘We report the detection of type-B quasi-periodic oscillation(QPO)of the black hole X-ray binary Swift J1728.9-3613 observed by NICER during the 2019 outburst.A type-B QPO was observed for the first two days and it disappeared as flux increased,but again appeared at∼7.70 Hz when flux was dramatically decreased.The source was found in the soft intermediate state during these observations.We further studied the energy dependence of the QPO.We found that QPO was observed only for a higher energy range implying that the origin of QPO is possibly due to the corona emitting higher energy photons by the inverse Compton process.The variation of spectral parameters can be explained with the disk truncation model.The fractional rms was found to be monotonically increased with energy.The phase lag spectrum followed the“U-shaped”curve.The rms and phase lag spectrum are modeled and explained with the single-component Comptonization model vkompthdk.
基金Financial support from the projects by the NSFC(51771166)the Hebei Natural Science Foundation(E2019203452,E2021203011)+4 种基金the central government guiding local science and technology development(216Z1001G)the talent project of human resources and social security department of Hebei province(A202002002)the key project of department of education of Hebei province(ZD2021107)Graduate Innovation Program of Hebei province(CXZZBS2020053)The work was supported by the State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2020-013).
文摘The Swift effect of Mg alloy is sensitive to initial texture.However,dislocation slip is the main deformation mechanism during torsion of Mg alloy.The underlying relation of Swift effect and dislocation slip is still not clarified.The effect of stress state and pre-straining on Swift effect was studied experimentally during free-end torsion for an extruded AZ31 alloy.The free-end torsion was performed with axial tension and compression stress which is lower than yield stress.It is found that the transition of axial deformation from contraction to elongation occurs when the axial stress changes from negative to positive.The pre-dislocations introduced by pre-tension promote axial shortening during torsion.While the pre-twins introduced by pre-compression are inhibition of axial shortening.The change of axial deformation is attributed to competition between twinning and prismatic slip.The axial shortening of extruded Mg alloy is generated by tensile twinning leading to c-axis strain.In contrast,the axial elongation can be generated by the activation of prismatic slip.The magnitude of axial strain generated by twinning is larger than that by prismatic slip.Moreover,the occurrence of detwinning results in axial elongation at low shear strain.
文摘Mainstream industrial policy research cannot fully explain how government interventions have helped China’s mobile communications industry catch up with and overtake those of advanced nations.China’s mobile communications industry made breakthroughs in 3G,caught up with advanced nations in 4G,and gained a leadership position in 5G due to the implementation and improvement of a strategy of industrial competition that accommodates mainstream standards and prioritizes the mid-band spectrum based on the integrated“technology,standard and industry”deployment system and swift decision-making.The introduction of a perspective of a strategy of industrial competition may supplement industrial policy research in the following ways:First,when the concerted actions of numerous innovators are important for industrial competition performance,an effective strategy of industrial competition can be devised and overall coordinated by the government provided that is compatible with the catch-up development of emerging technological industries.Second,an industrial policy becomes effective when it is complementary with the strategic factors for long-term industrial performance such as the strategy of industrial competition and avoids serious disruptions to market-based mechanisms.
文摘跨境金融通信对于现代金融业务的开展极为重要.环球银行金融电信协会(SWIFT)是跨境金融通信服务的主要提供者.现阶段,报文传输是 SWIFT 系统的主要业务,确保报文传输安全、准确、高效,是 SWIFT 系统的重要目标.但现阶段基于中心架构思想的 SWIFT 系统安全风险突出,传输效率低,成本较高.基于许可链分布式共识机制,提出 BCSWIFT 系统,对现有的 SWIFT 系统进行优化.首先,将 SWIFT 系统的传输网络划分为主网络层和附加网络层;其次,提出了基于双层网络结构的共识算法;第三,介绍了 BCSWIFT 系统的报文交互和传输机制;第四,出于金融业务数据商业保密考虑,提出了一种面向 BCSWIFT 系统的隐私保护机制;第五,对 BCSWIFT 系统的安全性进行了分析.以优化 SWIFT 系统的报文传输业务为例,阐释了基于许可链的跨境金融通信的基本机理,为确保跨境支付、清算、结算的安全、高效、准确和低成本化运作提供了新的思路,也为区块链技术大规模商业应用提供了重要参照.
