简介:Permanentmagnetscapableofreliablyoperatingathightemperaturesupto450?Carerequiredinadvancedpowersystemsforfutureaircrafts,vehicles,andships.ThoseoperatingtemperaturesarefarbeyondthecapabilityofNd–Fe–Bmagnets.PossessinghighCurietemperature,Sm–Cobasedmagnetsarestillveryimportantbecauseoftheirhightemperaturecapability,excellentthermalstability,andbettercorrosionresistance.Theextensiveresearchperformedaroundtheyear2000resultedinanewclassofSm2(Co,Fe,Cu,Zr)17-typemagnetscapableofoperatingathightemperaturesupto550?C.ThispapergivesasystematicreviewofthedevelopmentofSm–Copermanentmagnets,fromthecrystalstructuresandphasediagramstotheintrinsicmagneticproperties.AnemphasisisplacedonSm2(Co,Fe,Cu,Zr)17-typemagnetsforoperationattemperaturesfrom300?Cto550?C.Thethermalstabilityissues,includinginstantaneoustemperaturecoefficientsofmagneticproperties,arediscussedindetail.Thesignificanceofnanograinstructure,nanocrystalline,andnanocompositeSm–Comagnetmaterials,andprospectsoffuturerare-earthpermanentmagnetsarealsogiven.
简介:摘要在煤气发电岗位建立危险气体CO监测系统,是严格防范煤气泄漏、中毒事故发生的重要措施。本文主要介绍其组成、工作原理及维护标定。
简介:Twoaromaticco-polyamidesweresynthesizedcombiningtwodiacidmonomerscontainingbulkypendantgroups,5-(9,10-dihydro-9,10-ethanoanthracene-ll,12-dicarboximido)isophthalicacid(DEAIA)and5-tert-butylisophthalicacid(TERT),with4,4f-(hexafluoroisopropylidene)dianiline(HFA)or2,3,5,6-tetramethyl-l,4-phenylenediamine(Durene)bydirectpolycondensation.Thestructuresoftheobtainedaromaticco-polyamideswereconfirmedbyFTIR,Ramanand'H-NMR.Theco-copolyamidefilms,DHTHandDDTD,exhibitedrms-roughnessvaluesbetween0.94and1.60nm,respectively.Moreover,theypresentedgoodthermalstabilityupto300℃.Young'smodulioftheco-polyamidefilmswerebetween4.1and4.3GPa.X-raydiffractionresultsshowedthattheco-polyamidefilmswereamorphousduetotheincorporationofbothbulkypendantgroups,tert-b\xty\anddibenzobarrelene.Thecombinationofbulkypendantgroupsprovidedintrinsicallytransparentco-polyamidefilmswithatransmittancehigherthan88%intherangeof400-780nm.Duetotheseoutstandingfilmandopticalproperties,theyaresuggestedtobeflexiblesubstratesinapplicationsforsolarcellandotherportableelectronicdevices.
简介:摘要随着注CO2气体时间的延长和注入量的增加,剖面均衡性变差,注入的CO2气体前沿缘会沿高渗透条带突进,导致油井采出流体中CO2含量远超出最初的开发预测数据,导致部分油井井口出油温度过低,甚至造成井筒冻堵。建立CO2原油混合体系在井筒流动中的温度、压力耦合模型,编制“井筒流动温度和压力耦合计算软件”,分析了CO2摩尔分数、日产油量及井深对井口采出液温度的影响。结果表明,随着CO2摩尔分数增加,井口采出液温度降低;相同CO2摩尔分数下,随着井深、日产油量的增加,井口采出液温度均表现为逐渐增加的趋势。此外,该软件界面友好,方便现场人员操作,具有一定的工程实际价值。
简介:[ 摘要 ]松南腰英台气田是高产出二氧化碳气田,为了解决降低松南气田碳排放问题,提出改善邻近腰英台油田特低渗高含水裂缝发育油藏水驱开发效果,同时为特低渗高含水储层 CO2驱油提高采收率探索经验, 2011年起在腰西 DB33区块开展了 CO2非混相驱先导试验,现场实施分为连续注气和水气交替两个主要阶段。松南气田为腰英台油田注 CO2试验提供了充分的前提条件,并且很好地解决了松南气田天然气中 CO2 不能直接排放到大气层的问题。通过对试验区生产动态变化研究,总结出气驱收效时间与效果,注气受效后产出物的变化规律研究,为在今后特低渗油田注 CO2开发提供了科学借鉴。
简介:摘要压缩机是国民经济各部门必不可少的设备,应用十分广泛。压缩机绝大多数的故障发生在气阀上,分析了气阀所发生的各类故障及其发生的原因,并提出了合理的防治措施,从而延长了气阀的寿命,增大压缩机的产气量,降低功率消耗,提高了经济效益
简介:Theadaptivetreatmenttolerance(ATT)ofcancercellsisthemainencumbrancetocancerchemotherapy.Apotentialsolutiontothisproblemistotreatcancercellswithmultipledrugsusingnanoparticles(NPs).Inthisstudy,wetestedtheco-administrationofcurcumin(Cur)anddoxorubicin(Dox)toMCF-7resistantbreastcancercellstoblocktheATTandelicitefficientcellkilling.Drugswereco-administeredtocellsbothsequentiallyandsimultaneously.Sequentialdrugco-administrationwascarriedoutbypre-treatingthecellswithalbuminnanoparticles(ANPs)loadedw让hCur(Cur@ANPs)followedbytreatmentwithDox-loadedANPs(Dox@ANPs).Simultaneousdrugco-administrationwascarriedoutbytreatingthecellswithANPsloadedwithboththedrugs(Cur/Dox@ANPs).Wefoundthatthesimultaneousdrugco-administrationledtoagreaterintra-cellularaccumulationofDoxandcellkillingwithrespecttothesequentialdrugco-administration.However;thesimultaneousdrugco-administrationledtoalowerintracellularaccumulationofCurwithrespecttothesequentialdrugco-administration.WeshowedthatthisresultwasduetotheaggregationandentrapmentofCurinthelysosomesassoonasitwasreleasedfromCur@ANPs,aphenomenoncalledlysosomotropism.Incontrast,thesimultaneousreleaseofDoxandCurfromCur/Dox@ANPsintothelysosomesledtolysosomalpHelevation,which,inturn,avoidedCuraggregation,ledtolysosomeswellinganddrugreleaseinthecytosol,andfinallyprovokedefficientcellkilling.Ourstudyshedthelightonthemolecularprocessesdrivingthetherapeuticeffectsofanti-cancerdrugsco-administeredtocancercellsindifferentmanners.