简介:ToobtainthermotolerantmutantsofG.oxydans,whichcanenhancethetransformationrateofL-sorboseto2-Keto-L-gulonate(2-KLG)at33℃inatwo-stepprocessofvitaminCmanufacture,ionbeamwasusedasamutationsource.GluconobacteroxydansGOandBacillusmegateriumB0wereusedinthisstudy.TheoriginalstrainGluconobacteroxydansGOwasmutatedbytheheavyionimplantationfacilityattheInstituteofPlasmaPhysics,ChineseAcademyofSciences.SeveralmutantsincludingGluconobacteroxydansGI13wereisolatedandcoculturedwithBacillusmegateriumB0at33℃inshakingflasks.TheaveragetransformationrateofthenewmixedstrainGI13-B0inpergram-moleculereached94.4%aftersevenpassagesinshakingflasks,whichwasincreasedby7%whencomparedwiththeoriginalmixedstrainG0-B0(GluconobacteroxydansG0andBacillusmegateriumB0).Moreover,thetransformationrateofI13B0wasstableat94%attemperaturesrangingfrom25℃to33℃,whichwouldbeofmuchvalueinreducingenergyconsumptioninthemanufactureofL-ascorbicacid,especiallyintheseasonofsummer.Toclarifysomemechanismofthemutation,thespecificactivitiesofL-sorbosedehydrogenaseinbothG0andGI13wereestimated.
简介:Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.
简介:IntheframeworkoftheITER,qualificationtests,thefirstChinaTFconductorsample(CNTFl)wastestedattheSULTANfacility.ThesamplewasmadeoftwoTFconductorsectionsmanufacturedfromidenticalinternalstannumstrandsprovidedbytheOxfordSuperconductingtechnologycompany(OST).Inordertoevaluatetheconductorperformance,thecurrentsharingtemperature(Tcs)wasmeasuredatspecifiedelectromagneticloadcyclingsteps.BothconductorsectionsoftheCNTFlsampleshowedidenticalperformance.Tcswas7.2Kbeforecyclingloading,and6.9Kevenafter950cycles,withoutsignificantdegradation,whichsubstantiallyexceedstheITERrequirementof5.7K.ThetestsoftheCNTFlconductorsampleshowedthattheelectromagneticcyclicloadexhibitedanegligibleeffectontheconductorperformance.Thecouplingtimeconstant8forAClosswas214msand71.52msbeforeandafterthecyclingload,respectively.Thetestresultsofthesamplearecomparedwiththestrandperformanceandparametermodelanalysis.