The liquid-solid transitions of （Co2Si＋CoSi） and （CoSi＋CoSi2） eutectic alloys were realized in drop tube and the rapid eutectic growth mechanism of intermetallic compounds was examined. The experimental and calc...The liquid-solid transitions of （Co2Si＋CoSi） and （CoSi＋CoSi2） eutectic alloys were realized in drop tube and the rapid eutectic growth mechanism of intermetallic compounds was examined. The experimental and calculated results indicate that with increasing Co content, the intermetallic compound prefers nucleating primarily. The eutectic microstructures experience the transitions of ＇lamellar-anomalous-divorced＇ eutectic with undercooling. In undercooled state, the growth of CoSi intermetallic compound always lags behind others, and no matter how large the undercooling is, this intermetallic compound grows under the solutal diffusion control The calculated coupled zone demonstrates that （Co2Si＋CoSi） eutectic can form within certain undercooling regime, when the composition is in the range from 23.6% to 25.4% Si. And the calculated coupled zone of （CoSi＋CoSi2） covers a composition range from 40.8% to 43.8% Si.展开更多
Large-scale heterogeneous constellations will be the major forms of future space-based systems,and the implementation of numerous derived applications depends mainly on intersatellite communication.The nodes represent...Large-scale heterogeneous constellations will be the major forms of future space-based systems,and the implementation of numerous derived applications depends mainly on intersatellite communication.The nodes representing heterogeneous satellites will form the networks with rapidly changing topology.However,few researches have been carried out for such networks.This paper studies the broadcast mechanism for space dynamic networks and establishes centralized and distributed routing framework.And then,performance evaluation indicators are proposed to evaluate both the connectivity of dynamic networks and the effectiveness of routing algorithms.Finally,we examine the performance of multigroup networks and verify the rationality of corresponding indicators.We also explore the impact of information survival time which directly affects the delivery ratio and,if unfortunately,may waste the communication resources.Empirical conclusion about the survival time is given in the final part.We believe the performance indicators and the routing algorithms proposed in this paper are great help to future space-based system and both the broadcast mechanism designing.展开更多
基金supported by the National Natural Science Foundations of China (Grant Nos. 50871090, 50971104 and 50901060)the NPU Foundations for Fundamental Research (JC20110279)the financial support from the National Aerospace Science Foundation of China (Grant Nos. 2008ZF53052 and 2010ZF53059)
文摘The liquid-solid transitions of （Co2Si＋CoSi） and （CoSi＋CoSi2） eutectic alloys were realized in drop tube and the rapid eutectic growth mechanism of intermetallic compounds was examined. The experimental and calculated results indicate that with increasing Co content, the intermetallic compound prefers nucleating primarily. The eutectic microstructures experience the transitions of ＇lamellar-anomalous-divorced＇ eutectic with undercooling. In undercooled state, the growth of CoSi intermetallic compound always lags behind others, and no matter how large the undercooling is, this intermetallic compound grows under the solutal diffusion control The calculated coupled zone demonstrates that （Co2Si＋CoSi） eutectic can form within certain undercooling regime, when the composition is in the range from 23.6% to 25.4% Si. And the calculated coupled zone of （CoSi＋CoSi2） covers a composition range from 40.8% to 43.8% Si.
基金This research was supported by the National Key R&D Program of China under Grant 2018YFA0703800.
文摘Large-scale heterogeneous constellations will be the major forms of future space-based systems,and the implementation of numerous derived applications depends mainly on intersatellite communication.The nodes representing heterogeneous satellites will form the networks with rapidly changing topology.However,few researches have been carried out for such networks.This paper studies the broadcast mechanism for space dynamic networks and establishes centralized and distributed routing framework.And then,performance evaluation indicators are proposed to evaluate both the connectivity of dynamic networks and the effectiveness of routing algorithms.Finally,we examine the performance of multigroup networks and verify the rationality of corresponding indicators.We also explore the impact of information survival time which directly affects the delivery ratio and,if unfortunately,may waste the communication resources.Empirical conclusion about the survival time is given in the final part.We believe the performance indicators and the routing algorithms proposed in this paper are great help to future space-based system and both the broadcast mechanism designing.
