Vol.28 No.12 翟正利等：基于模糊Petri网和本体的网格服务发现 .1201. Grid service discovery based on fuzzy Petri net and ontology ZHAI Zhengli),YANG Yang) 1)Information Engineering School.University of Science and Technology Beijing Beijing 100083,China 2)College of Information.Linyi Normal University.Linyi 276005.China ABSTRACI A multi-agent-based grid service discovery framework was put forw ard,in which agents were distinguished into three categories:service-agent,request-agent and service-discovery agent.A service de- scription language based on fuzzy Petri nets (FPN-SDL)was proposed as a specification to publish or re- quest for a service,it used possibility transition to represent a service or request,input places and output places to denote conditions before and after performing the service respectively,and possibility and necessity to quantify the confidence levels that the service could satisfy a request.At last this paper presented a se- mantic based service matchmaking that can find an appropriate service for a request and support partial matching,and illuminated these through an example of the vehicle maintenance service system. KEY WORDS grid service;service discovery;multi-agent;service description language (SDL);fuzzy Petri net (FPN);ontology;service matchmaking (上接第1138页) Evolution of molybdenum sulfide in iron -based self-lubrication alloys CUI Feng'e,YANG Ping,BIAN Jianhua Materials Science and Engineering School.University of Science and Technology Beijing.Beijing 100083.China ABSTRACT Iron-based sulfides self-lubricating alloys with different contents of molybdenum were pre- pared with a medium -frequency induction furnace.The evolution of molybdenum sulfide in these alloys was studied by scanning electron microscope and X-ray diffractometer.The results showed that only FeS formed in the alloy and Mo presented as Fe3Mo2 with a Mo mass fraction of 1.5%.When the mass fraction of Mo was 6.5%,no MoSzformed,and Mo still presented as FesMoz.When the mass fraction of Mo was 11%, only a small quantity of MoS,could form and great majority of Mo and Fe formed the compound Fe3Moz. MoS formed remarkably when the mass fraction of Mo was up to 19.5%.It is difficult for molybdenum sulfides to be formed with Mo mass fractions less than 10%.Annealing treatment is favorable for MoSx formation,but no pure MoSz was found in the above alloys.MoS:is a metastable phase formed through the decomposition of Fe Mo S compounds.V,Nb and Ti,which are used to decrease grain size in the alloys, are disadvantageous for the formation of molybdenum sulfides due to their strong bonding force to sulfur. Aluminum used as deoxidant should be added in a small amount. KEY WORDS iron-based self-lubricating alloys:high-sulphur alloy steel;tribological properties;low car- bon steel;sulfides;microstructureGrid service discovery based on fuzzy Petri net and ontology ZHAI Zhengli 1‚2）‚Y A NG Y ang 1） 1） Information Engineering School‚University of Science and Technology Beijing‚Beijing100083‚China 2） College of Information‚Linyi Normal University‚Linyi276005‚China ABSTRACT A mult-i agent-based grid service discovery framework was put forward‚in which agents were distinguished into three categories：service-agent‚request-agent and service-discovery-agent．A service de￾scription language based on fuzzy Petri nets （FPN-SDL） was proposed as a specification to publish or re￾quest for a service‚it used possibility transition to represent a service or request‚input places and output places to denote conditions before and after performing the service respectively‚and possibility and necessity to quantify the confidence levels that the service could satisfy a request．At last this paper presented a se￾mantic-based service matchmaking that can find an appropriate service for a request and support partial matching‚and illuminated these through an example of the vehicle maintenance service system． KEY WORDS grid service；service discovery；mult-i agent；service description language （SDL）；fuzzy Petri net （FPN）；ontology；service matchmaking （上接第1138页） Evolution of molybdenum sulfide in iron-based self-lubrication alloys CUI Feng’e‚Y A NG Ping‚BIA N Jianhua Materials Science and Engineering School‚University of Science and Technology Beijing‚Beijing100083‚China ABSTRACT Iron-based sulfides self-lubricating alloys with different contents of molybdenum were pre￾pared with a medium-frequency induction furnace．The evolution of molybdenum sulfide in these alloys was studied by scanning electron microscope and X-ray diffractometer．The results showed that only FeS formed in the alloy and Mo presented as Fe3Mo2with a Mo mass fraction of1∙5％．When the mass fraction of Mo was6∙5％‚no MoS2formed‚and Mo still presented as Fe3Mo2．When the mass fraction of Mo was11％‚ only a small quantity of MoS x could form and great majority of Mo and Fe formed the compound Fe3Mo2． MoS x formed remarkably when the mass fraction of Mo was up to19∙5％．It is difficult for molybdenum sulfides to be formed with Mo mass fractions less than 10％．Annealing treatment is favorable for MoSx formation‚but no pure MoS2was found in the above alloys．MoS x is a metastable phase formed through the decomposition of Fe—Mo—S compounds．V‚Nb and Ti‚which are used to decrease grain size in the alloys‚ are disadvantageous for the formation of molybdenum sulfides due to their strong bonding force to sulfur． Aluminum used as deoxidant should be added in a small amount． KEY WORDS iron-based self-lubricating alloys；high-sulphur alloy steel；tribological properties；low-car￾bon steel；sulfides；microstructure Vol．28No．12 翟正利等： 基于模糊 Petri 网和本体的网格服务发现 ·1201·