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1.
Becauseoftheirpossiblerelevancetomodelcompoundsofcationtransportacrossmembranes,differenttypesofopenchain“crown”ethermoleculeshavebeensynthesizedinordertostudytheirinteractionwithsodium ,potassiumandrareearthions[1,2 ] .Panetal.[3 ] showedthatCe3 formsa 1∶1com…  相似文献   

2.
Owingtothevariationofcoordinatedmodesforcarboxylateanions ,manydifferenttypesofcrystalstructuresfortherareearthcomplexeswitharomaticacidandnitrogen containingligandswereobtained[1~ 4 ] .Theirthermaldecompositionbehaviorhadbeenre portedinpreviouspapers[5~ 8] .…  相似文献   

3.
Crystalengineeringofcoordinationpoly merswithopenframeworksassembledfromor ganic metalcompoundshasbeenofgreatinter estsowingtotheirpotentialpropertiesasnovelmaterialssuchasgasadsorption[1,2 ] ,ion ex change[3] andcatalysis[4] .Theconstructionofcoordinationpolym…  相似文献   

4.
Teapolysacchridecomplex ,oneofthebasicmacromoleculesintea ,hasmanyphar maceuticaleffectsandiseasytodissolveinteainfusion[1] .Zhongetal .[2 ] discoveredthatthereisaREbindingpolysaccharideinleavesofteaplant (CamelliaSinensisLO .Kuntze) .Inthispaper ,thestudyontheco…  相似文献   

5.
Surfacetensionofmoltensaltisoneofsignificantpropertiesinmetallurgyandmateri alsengineering .BasedonButler′sequation[1]andusingexcessthermodynamicdataofmix ing ,Tanakaetal.[2 ,3] welldevelopedseveralmodelstodeterminesurfacetensionofmoltensaltmixturesincommoni…  相似文献   

6.
TherehavebeensomereportsonthemechanismofthestressinjurybyPbpollutioninplant[1~ 4] .TheinjuryunderPbstresswasrelatedtothedestroyofsupermicrostructureofcellnucleuses,mitochondrion ,chlorophast[5] ,sothatthecontentsofthechlorophyllandascorbicacid[1 ,4,5] ,theactivi…  相似文献   

7.
Themagneticpropertiesofheteropolynu clearcomplexescontainingboth 4fand 3dionshaveattractedconsiderableinterestssince1 985 [1] .Carboxylicacidisakindofpotentialligandforthedesignandsynthesisofthiskindofmagneticmolecularmaterials .Somecar boxylatecompoundswerep…  相似文献   

8.
Thehighluminousefficiencyandbetterdisplayoftricolorphosphormaterialswasde siredforalongtime ,CeandTbco activatedluminescencematerialhaveattractedtheatten tionofscientists[1~ 5 ] .Thosematerialsarephosphate ,borate ,aluminatesofalkaline ,rareearth ,alkalineandr…  相似文献   

9.
CationicradiusofrareearthelementsisclosetothatofCa2 .ItisgenerallysuggestedthatthereplacementofCa2 byTb3 inducessomealterationsofnativestructureofcalmod ulin (CaM ) [1] ,andtheresultingchangesinbiologicaleffectmaybeacauseoftoxicityofrareearths[2 ] .Wangetal[3] fo…  相似文献   

10.
ItisnowwellestablishedthatnumerousfactorsinfluencethereactionpathwaysinsuchacomplicatedY Ba Cu Osystem ,forin stance ,thecrystallinesizesandthereagent[1] ,thedegreeofmixingandhomo geneity[2 ,3] ,theoxygenpartialpressure[4~ 6 ] ,aswellasthereactorsizeandcrucibleshap…  相似文献   

11.
Perovskite typeoxides (generalformulaABO3 )havebeenattractingmuchattentionformorethantwodecadesduetotheirpotentialcommercialapplicationsascatalystsforvariousreactions :oxidationofCO[1~ 3 ] andlighthy drocarbons[4~ 7] ,combustionofnaturalgasorCH4 [8~ 1 1 ] (tocontrolN…  相似文献   

12.
Recently ,therehasbeenconsiderablein terestinlanthanide(Ⅲ )hexacyanoferratesandtheanalogouscobalt(Ⅲ )aswellaschromium(Ⅲ )complexesbecauseoftheirpotentialascatalytic ,semiconductive ,andmagneticmate rials[1~ 4] .Forexample ,magneticstudiesonaseriesofthree dimensio…  相似文献   

13.
Luminescentlanthanidecomplexeshavebeenintensivelystudiedfortheirwideapplica tionsinphoto devicesandfluoro analysis ,es peciallyintheuseasluminescentlabelsinflu oro immunoassayfield[1] .Sincetheback groundluminescenceofbiologicalmaterialsisusuallyshort lived…  相似文献   

14.
Amonglanthanideions ,Eu3 + ionposs esesgoodluminescentcharacteristics ,highcolorpurityandhighquantumefficiency .Eu3 + isoneofthecentralionsfirstselectedforthepreparationofrareearthionsdopedlumi nescentmaterials .Dafinovaetal .[1] producedEu3 + andSO2 -4 dopedtungsta…  相似文献   

15.
Catalytic Oxidative Properties and Characterization of CuO/CeO2 Catalysts   总被引:1,自引:0,他引:1  
CeO2 ormaterialscontainingCeO2 possessuniqueredoxpropertiesincatalyticprocesses[1~ 3] ,andcanimprovedispersionofactivecomponentsonthesup portsandthusenhancetheirthermalstabilityandcatalyticactivity .MoststudieshaveusedCeO2 asanadditive[4 ] andexamineditsintera…  相似文献   

16.
Effect of Cerium on Seed Germination under Acid Rain Stress   总被引:5,自引:0,他引:5  
Plantsharmedbytheacidicraininterres trialecosystemshasbeenreportedinmanycases[1~ 4] .Macroscopicanalysisshowsthatacidrainharmsplantstotheirgroundandun dergroundorgansandthelatterisduetotheacidificationofsoilenvironment.Itfollowsthattheacidifiedsoilaffects…  相似文献   

17.
Thepoormechanicalpropertiesofcastmaterials ,especiallylowtoughness ,isamainfactorlimitingtheapplicationofprecisecastdies[1] .ThroughthemodificationofcastH1 3steelbyRE ,thedendritesegregationofCH1 3steelwasimprovedandgrainboundarycarbidewasalsoundercontrol.Acc…  相似文献   

18.
Itiswellknownthatorganophorusextrac tantsdi (2 ethylhexyl ) phosphoricacid(HDEHP )and 2 ethyhexyl 2ethylhexyphos phonicacid (HEH/EHP)havebeenwidelyusedintherareearthhydrometallurgicalsepa rationprocess[1~ 5 ] .However ,thelowselectiv ityforheavylanthanides (Ln3 )andh…  相似文献   

19.
Nucleicacidsplayimportantrolesinthemolecularbiology.Theenormousgrowthinthenucleicacidresearchhasresultedinaneedformethodssuit...  相似文献   

20.
Effect of Oxide Scale on Interfacial Heat Transfer during Slab Hot Rolling   总被引:1,自引:0,他引:1  
Inhotrollingofslab ,thetheoriesofheattrans ferandtemperaturedistributionwerewidelyrecog nizedandusedinpractice[1 4 ] .However ,thequanti tativecharacterizationoftheinterfacialheattransferandtemperaturedistributionisstillincompleteandinconsistentandinmostcas…  相似文献   

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