In this paper,a numerical model of fretting fatigue analysis of cablewire and the fretting fatigue damage constitutive model considering the multi-axis effect were established,and the user material subroutine UMAT was...In this paper,a numerical model of fretting fatigue analysis of cablewire and the fretting fatigue damage constitutive model considering the multi-axis effect were established,and the user material subroutine UMAT was written.Then,the constitutive model of wear morphology evolution of cable wire and the constitutive model of pitting evolution considering the mechanical-electrochemical effect were established,respectively.The corresponding subroutines UMESHMOTION_Wear and UMESHMOTION_Wear_Corrosion were written,and the fretting fatigue lifewas further predicted.The results showthat the numerical simulation life obtained by the programin this paper has the same trend as the tested one;the error is only about 0.7%in the medium life area;When the normal contact force increases from 120 to 240 N,the fretting life of cable wire decreases by 25%;When the evolution of wear morphology and corrosion effect are considered simultaneously,the depth of the wear zone exceeds 0.08mm after 600,000 loads,which ismuch larger than 0.04 mmwhen only the evolution of wear morphology is considered.When the evolution of wear morphology and corrosion morphology is considered simultaneously,the damage covers the whole contact surface after 300,000 loads,and the penetrating damage zone forms after 450,000 loads,which is obviously faster than that when only the wearmorphology evolution is considered.Themethod proposed in this paper can provide a feasible numerical simulation scheme for the visualization of the damage process and accurate life prediction of cable-supported bridges.展开更多
A new category of system model, multiserver multiqueuenetwork(MSMQN), is proposed for distributed systems such as thegeographically distributed Web-server clusters. A MSMQN comprisesmultiple multiserver multiqueue(MSM...A new category of system model, multiserver multiqueuenetwork(MSMQN), is proposed for distributed systems such as thegeographically distributed Web-server clusters. A MSMQN comprisesmultiple multiserver multiqueue(MSMQ)nodes distributed over thenetwork, and every node consists of a number of servers that eachcontains multiple priority queues for waiting customers. An in-coming request can be distributed to a waiting queue of any server inany node, according to the routing policy integrated by the node-selection policy at network-level, request-dispatching policy atnode-level, and request-scheduling policy at server-level.展开更多
The production of transgenic swine for xenotransplantation has been proposed as an optimal option to overcome the chronic shortage of human organ donors. Generation of genetically engineered swine has been elusive due...The production of transgenic swine for xenotransplantation has been proposed as an optimal option to overcome the chronic shortage of human organ donors. Generation of genetically engineered swine has been elusive due to the difficulties in gene transfer. In order to achieve effective gene delivery, a key step for the genetic modification, we applied electronic pulse delivery (EPD) technology to introduce HZKb-DC DNA construct into swine eggs. Using the developed EPD ProtocolsTM, we have achieved good viability of the EPD treated oocytes, satisfactory embryonic development of the EPD treated embryos, and stable DNA transfer into the swine embryos with high efficiency. Thus, application of the EPD technology promises to effectively facilitate the generation of large trangenic mammals.展开更多
The latest trend of regulation about efficacy claims of cosmetics in China and EU has been analyzed. It is suggested that the cosmetic companies should make preparation.
基金supported by the grant from National Key Research and Development Program of China (Grant No.2021YFF0602005)National Natural Science Foundation of China (No.51678135),which are gratefully acknowledged.
文摘In this paper,a numerical model of fretting fatigue analysis of cablewire and the fretting fatigue damage constitutive model considering the multi-axis effect were established,and the user material subroutine UMAT was written.Then,the constitutive model of wear morphology evolution of cable wire and the constitutive model of pitting evolution considering the mechanical-electrochemical effect were established,respectively.The corresponding subroutines UMESHMOTION_Wear and UMESHMOTION_Wear_Corrosion were written,and the fretting fatigue lifewas further predicted.The results showthat the numerical simulation life obtained by the programin this paper has the same trend as the tested one;the error is only about 0.7%in the medium life area;When the normal contact force increases from 120 to 240 N,the fretting life of cable wire decreases by 25%;When the evolution of wear morphology and corrosion effect are considered simultaneously,the depth of the wear zone exceeds 0.08mm after 600,000 loads,which ismuch larger than 0.04 mmwhen only the evolution of wear morphology is considered.When the evolution of wear morphology and corrosion morphology is considered simultaneously,the damage covers the whole contact surface after 300,000 loads,and the penetrating damage zone forms after 450,000 loads,which is obviously faster than that when only the wearmorphology evolution is considered.Themethod proposed in this paper can provide a feasible numerical simulation scheme for the visualization of the damage process and accurate life prediction of cable-supported bridges.
基金[This work is financially supported by the National Natural Science Foundation of China (No. 90104002 and 60173012), the Projects of Development Plan of the State Key Fundamental Research (No. G1999032707) and the Projects of Development Plan of the Stat
文摘A new category of system model, multiserver multiqueuenetwork(MSMQN), is proposed for distributed systems such as thegeographically distributed Web-server clusters. A MSMQN comprisesmultiple multiserver multiqueue(MSMQ)nodes distributed over thenetwork, and every node consists of a number of servers that eachcontains multiple priority queues for waiting customers. An in-coming request can be distributed to a waiting queue of any server inany node, according to the routing policy integrated by the node-selection policy at network-level, request-dispatching policy atnode-level, and request-scheduling policy at server-level.
文摘The production of transgenic swine for xenotransplantation has been proposed as an optimal option to overcome the chronic shortage of human organ donors. Generation of genetically engineered swine has been elusive due to the difficulties in gene transfer. In order to achieve effective gene delivery, a key step for the genetic modification, we applied electronic pulse delivery (EPD) technology to introduce HZKb-DC DNA construct into swine eggs. Using the developed EPD ProtocolsTM, we have achieved good viability of the EPD treated oocytes, satisfactory embryonic development of the EPD treated embryos, and stable DNA transfer into the swine embryos with high efficiency. Thus, application of the EPD technology promises to effectively facilitate the generation of large trangenic mammals.
文摘The latest trend of regulation about efficacy claims of cosmetics in China and EU has been analyzed. It is suggested that the cosmetic companies should make preparation.
