RELATIONSHIP BETWEEN TENSILE DEFORMATION BEHAVIOUR AND MICROSTRUCTURAL PARAMETERS OF A DUAL PHASE STEEL

Based on the deformation model of dual phase steels,an expression for the stress of martensile in dual phase steels is derived,it predictes that the onset of plastic deformationof martensite (transition strain) depends on the strain hardening of ferrite and on thestrength of martensite.The relationship between the flow stress and microstructural parameters of a 0.12C-0.9Mn dual phase steel was investigated using the expression forthe flow stress of dual phase steel.By calculating the stress ratio and the stress-strainpartition coeffictient,the load transition and the stress-strain partition between two phases are studied.It shows that the deformation of dual phase steel lies between the isostress and isostrain states and the stress-strain pratition changes continuously during the deforamtion.     

熔锥型光纤耦合器损耗分析

利用几何光学理论对光纤耦合器的损耗进行分析 ;当环境介质折射率发生变化时光纤耦合器的损耗随之变化 ,理论推导损耗与环境介质折射率的关系公式 ,实验中利用OTDR检测反射光实现环境介质折射率变化的监测 ,利用拉锥机监视损耗的变化 ,得到的实验值与公式计算值基本吻合 ,证实了耦合器锥区环境介质折射率恒定是高质量耦合器的保证     

Network aspects of integrating 5G and satellite communication

Since 2017, 3rd Generation Partnership Program (3GPP) is working on integration of satellite communication in 3GPP. This paper discusses the results of the work on service and network architecture aspects in 3GPP Technical Specification Group (TSG) Service and System Aspects (SA) and 3GPP TSG Core Networks and Terminals (CT). This paper does not discuss radio aspects as are specified in 3GPP TSG radio access network (RAN). 3GPP first specified requirements and use cases for satellite access. Subsequently, architecture and protocol specifications were created for integration scenarios, direct access, network selection, mobility management, and satellite backhaul with quality of service (QoS). Also, impacts of regulatory aspects on satellite integration have been discussed in 3GPP. With the completion of Release 17, 3GPP specifications are now ready for implementation of integrated 5G satellite networks. 3GPP will continue with further development of satellite integration in Release 18 and Release 19.