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1.
Polymerscontainingthiolandsulphoxidewhichhaveactive—SHand—SOgroupswereusedinbiological,pharmaceutical,industrialandotherchemicalfields .As—SHand—SOgroupsareeasytoformcomplexeswithmetals ,sotheyhavearouseanincreasinginterestofmanyauthors .Alargenumberoffu…  相似文献   

2.
EffectofFluoridesandCeriumDioxideAdditivesonEPandAntiwearPerformanceofGreaseLianYafeng(连亚锋)(GuangzhouMachineToolResearchInsti...  相似文献   

3.
Itwasproved[1] thatrareearthelements(REE)promotethegrowthanddevelopmentofplants ,andincreasetheyieldofcrops .How ever ,theirmechanismarestilllittleknown .ItwasknownthatREEincreasestheactivitiesofsomeenzymesandacceleratestheproceedingofphotosynthesisinplants …  相似文献   

4.
Alotofworkhasbeendoneontheeffectofrareearthelementsonplantgrowthandphysiologicalactiv ities .ResultshaveshownthatREEsappliedbyfoliarsprays ,seedtreatmentsoradditiontothesoilsandso lutionmediacanincreasegraincrops ,economiccrops ,andvegetablesby 5 0 %~ 12 % ,8 0 %…  相似文献   

5.
Rareearthelements (REEs)areabletoincreaseyieldofcropsandimproveproductquality[1] .Inrecentyears ,REEswerewidelyusedasfertilizerinagricultureinChina[2 ] .Chenetal.[3] reportedtheconcentrationofREEsinvarioussoillayersincreasedsignifi cantlyincomparisonwiththatint…  相似文献   

6.
since 1 960s ,theresearchoftheZieglercatalystapplyingtothepolymerizationofacry latehasbeenincreasing[1~ 3] ,forexamplethepolymerizationofacrylatewithzirconiumorrareearthcatalystshasbeenpublished[4~ 6 ] .However ,thepolymerizationmechanismoftheacrylatewiththetrans…  相似文献   

7.
Inthepastfewyears ,themagneticprop ertiesofcomplexescomprisinglanthanideandtransitionmetalionshaveattractedincreasinginterest[1~ 6 ] .Thesecomplexesareimportantinthestudiesofmagneticexchangeinteractionbetweenlanthanideandd transitionmetalions,andtheycanpro…  相似文献   

8.
Rareearthsandtheircompoundshavealotofoutstandingpropertiesandarepaidincreasingattentionto.NumerousinvestigationsfortheternarysystemRENiSnhavebeendone.ThecrystalstructuredeterminationofthecompoundCeNi5Snbyreciprocallatticephotographyhasbeenreportedw…  相似文献   

9.
Polyεcaprolactoneisofgreatinterestformedicalapplicationsbecauseoftheirbiodegradability,biocompatibilityandpermeabilitytomanydrugs.Increasingattentionispaidtoexplorelanthanidecomplexassinglecomponentcatalystsforringopeningpolymerizationofεcaprolactone.…  相似文献   

10.
CellcultureofTaxusspp .maybeviewedasapotentialalternativetowholeplantextrac tionasasourceoftheantineoplasticagenttax olandrelatedtaxanes ,currentlyinshortsup ply .Therefore ,howtoincreasetheproductivi tyoftaxolintheplantcellculturehasdrawnmuchattention .Eli…  相似文献   

11.
Methanationcatalystisanimportantoneinfertilizerandpetroleumindustry .SupportedNi basedcatalystisoneofthesekindsofcata lystsbeingstudiedmostly .Inrecentyears ,peoplehavefoundthattheadditionofrareearthoxidescaneffectivelyincreasetheperfor mancesofmethanati…  相似文献   

12.
areearthshaveabeneficialeffectsonpromotingthecropgrowthandincreasingitsyield .Someresearchershavedemonstratedthattherareearthscannotentertheprotoplastandonlystayoutsidetheplasmamembrane[1] .Thereisanoxidation reduction (redox)systemontheplasmamembraneofpl…  相似文献   

13.
Study on Electro-Capillary Oscillation in ESR System   总被引:1,自引:0,他引:1  
nterfacebetweenmetalpoolandslagpoolstronglyoscillatewhenanalternatecurrentpassingtheinterfaceduringtheprocessofelectroslagremelt ing .Thisphenomenonissocalledelectro capillaryoscillation[1] .ЕсинОАetalthoughtthatelectro capillaryos cillationstrengthensrea…  相似文献   

14.
Rareearthelementsareusedwidelybe causeoftheirspecialelectrical,magneticandopticalnatures .Withthehigh speeddevelop mentofmodernscienceandtechnology ,theneedforrareearthswithhighpurityisincreas ing .Soitisveryinterestingtostudythesepa rationandpurificationo…  相似文献   

15.
Itwasthoughtthattherareearthswerenotcarbideformingelementsbasedonthefactthattherareearthsreactoncarboninsteelsimilarlytosilicon ,theelementwhichneverformscarbideandisdifferentfromtheele mentssuchaschromium ,manganeseandtung stenwhichformcarbides .Moreove…  相似文献   

16.
Itwasprovedbypreviousworks[1] thatrareearthelementspromotethegrowthandde velopmentofplantsandincreasetheyieldofcropsatlowconcentration ,butwhenthecon centrationishigh ,theywillinhibitthegrowthofplants .Itwasalsoproved[2 ,3] thatrareearthelementsexhibitbothpos…  相似文献   

17.
Ceramicmaterialshavebeenusedasen gineeringmaterialsbecauseoftheirhighstrengthandhighhardness .Thedisadvantageofsuchceramicsisthedifficultyinmachiningaftersintering ,whichleadstohighmachiningcost.Todecreaseit ,variousceramicswithreasonablemachinability ,ca…  相似文献   

18.
Inrecentyears ,thedemandforhighercleanli nesssteelhasbeen greatlyincreased .Alargeamountofhighqualitysteelrequiresthephosphoruscontentlowerthan 0 .0 15 % .Thephosphoruscon tentinsomespecialsteeltypes ,forexample ,steelpipeforlowtemperature ,specialdeep drawingste…  相似文献   

19.
Mechanism of Effect of Lanthanum Nitrate on Vigor of Aged Rice Seeds   总被引:2,自引:0,他引:2  
Seedsearlydegeneratedoragedbyun suitablecultivationorunstoragetechniquesmayresultindecreasingofseedvigorandofthecropsoutput,especiallyforrice.Rareearthsacceleratethegerminationandgrowthofthecrops ,suchasrice ,wheat,barley ,veg etablesandoilplants[1~ 3] .Thest…  相似文献   

20.
Twinrollstripcastingisregardedasaprospec tivetechnologyofnearnetshapecontinuouscastingwhichisusedtoproducestripsof 1 6mm .Present ly ,thistechnologyisbecomingmaturedandcom mercialized .Thekeyproblemishowtoensurebothstrip qualityandsmoothoperation .Areasonabl…  相似文献   

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