简介：Fuzzyassociationrules(FARs)canbepowerfulinassessingregionalsoilquality,acriticalsteppriortolandplanningandutilization;however,traditionalFARsminedfromsoilqualitydatabase,ignoringtheimportancevariabilityoftherules,canberedundantandfarfromoptimal.Inthisstudy,wedevelopedamethodapplyingdifferentweightstotraditionalFARstoimproveaccuracyofsoilqualityassessment.AftertheFARsforsoilqualityassessmentweremined,redundantruleswereeliminatedaccordingtowhethertherulesweresignificantornotinreducingthecomplexityofthesoilqualityassessmentmodelsandinimprovingthecomprehensibilityofFARs.Theglobalweights,eachrepresentingtheimportanceofaFARinsoilqualityassessment,werethenintroducedandrefinedusingagradientdescentoptimizationmethod.ThismethodwasappliedtotheassessmentofsoilresourcesconditionsinGuangdongProvince,China.Thenewapproachhadanaccuracyof87%,when15rulesweremined,ascomparedwith76%fromthetraditionalapproach.Theaccuracyincreasedto96%when32rulesweremined,incontrastto88%fromthetraditionalapproach.TheseresultsdemonstratedanimprovedcomprehensibilityofFARsandahighaccuracyoftheproposedmethod.

简介：Thechangesofclaymineralassociationafterhigh-gradientmagneticseparation(HGMS)treatment,andtheeffectsofchemicalandphysicaltechnologiesonconcentratingFeoxidesformiansoilsincentralandsouthernChinawereinvestigatedbymeansofX-raydiffraction(XRD)andchemicalanalysismethods.ResultsindicatedthattheconcentratingtimesofFeoxidesbyHGMStreatmentwerethelargestfor0.2-2μmsizefractionintheexaminedsoils.Forthesoilsinwhich2:1phyllosilicatesweredominant,concentratingtimesofironoxidesbyHGMStreatmentwerelargerthanby5molL^-1NaOHtreatment.Phyllosili-catesweredecreasedafterHGMStreatment;however,thedecreasewaslessthanthatofkaolinite,Thegoethite/(goethite+hematite)valuesinFeoxidesofthesoilskeptvirtuallyconstantafterHGMStreatment.