简介:Theroleofnano-SiO2andultra-fineboroncarbideonthepropertiesofalumina-graphitematerialswasinvestigated.Thestudyshowedthattheultra-fineboroncarbideaddedmodifiedthemicrostructureofresidualcarbonandpromotedthechemicalbondbetweenresidualcarbonfromphenolicresinandflakegraphite.Thecarbonwhitecouldstrengthentheresidualcarbonfromphenolicresin.ThesetwoadditivesimprovedthemechanicalpropertiesofAGrefractoriesatbothroomtemperatureandhightemperature,andthermalshockresistancewasimprovednoticeably.Whenthetwoadditivesweredopedtogether,carbonwhitecouldretardtheevaporationofB2O3.Thermalshockresistancewasguaranteedwithasmalleramountofultrafineboroncarbide.
简介:C3植物C4植物C3—C4中间植物在解剖结构和生理生化方面存在一定差异,C4植物与C3植物相比为低CO2补偿点,低光呼吸的高光合效率植物。而C3—C4中间植物则介于C3植物和C4植物之间。这类中间植物为研究C4植物进化,光呼吸如何降低提供了实验系统。
简介:Thetitlecomplexi-C4H9Co(salen)(Py)(Py=pyridine.salen=dianionofdisalicylideneethylenediamine)hasbeenfirstsynthesized.ItscrystalstructurehasbeendeterminedbyX-raydiffractionmethod.ThecrystsisaremonoclinicwithspacegroupP21/C.Theunitcellparametesarepresented.ThestructurehasbeenrefinedtoafinalRof0.038.
简介:Intwopreviouspaperspublishedintheprecedingvolumesofthisjournal,differentaspectsoftheuseofforeigncourtsbyGreekcitiesintheHellenisticPeriodhavebeenstudied.InJAC7,anattemptwasmadetosettheroleofforeigncourtsagainstthewiderbackgroundofthedevelopmentofpoliticalinstitutionsandpracticesinthecourseoftheHellenisticperiod.InJAC8theuseofforeignjudgesbySeleucidsubjectcitieswasreconsideredinthelightoftherevisionofanimportantinscriptionfromPriene.Inthisthirdpaper,theevolutionoftheuseofforeigncourtsbyGreekcitiesinthecourseofthethirdcenturywillbeconsideredinformaltermsthroughtheanalysisofanotableseriesofinscriptionsfromtheislandofKalymnaintheDodecannesegroup,locatedoffthesouth-westcoastofAsiaMinor.InhisCorpusofinscriptionsfromKalymna(TC),M.Segrecollected,inadditiontotherecordofaKnidianarbitrationbetweenKalymnaanditsKoanprivatecreditors(TC79),fiveinscr