简介:Agriculturalapplicationofrareearth(RE)hasbeengeneralizedforseveraldecades,anditisinvolvedincrops,vegetablesandstockraisinginChina.However,alltheresearchesonREmainlyfocusonthefieldssuchasplantphysiologicalactivity,physiologicalandbiochemicalmechanism,sanitationtoxicologyandenvironmentalsecurity.PlantprotectionbyusingREandtheinducedresistanceofplantagainstdiseasesweresummarized.Themechanismofrareearthagainstplantdiseaseishighlighted,whichincludesfollowingtwoaspects.First,REelementscancontrolsomephytopathogendirectlyandreduceitsvirulencetohostplant.AnotherpossibilityisthatREelementscanaffecthostplantandinducetheplanttoproducesomeresistancetodisease.
简介:Theneedformoreactiveandhydrothermallystablefluidcatalyticcracking(FCC)catalyststocombattheeffectofmetalcontaminantshasledtoanincreaseindemandforrareearthoxides.RareearthoxidesenhancecatalystactivityandpreventthelossofacidsitesduringtheFCCunitoperation,especiallywhenheavyresiduewithhighmetalcontentisusedasfeed.Inthispaper,areviewwascarriedouttoshowtheeffectsofrareearthelementsonthestructure,activity,andstabilityofFCCcatalysts.Also,theuseofrareearthelementsasvanadiumtrapswasanalyzedinconjunctionwiththemechanismofcatalystdeactivationbyvanadium.TheobjectivewastoelucidatetheinteractionofvanadiumspecieswiththezeolitecomponentoftheFCCcatalystsandtheroleofrareearthelementsincounteringthedeleteriouseffectsofvanadiumontheFCCcatalysts.