简介:Manyofusbelievethataperson'smindbecomeslessactiveashegrowsolder.Butthisisnot.true,accordingtoDr.LissyF.Jarvik,professorofpsychiatry(精神病学)attheUniversityofCalifomia,LosAngeles,andaboardmemberoftheNewCenterforAgingattheVeteransHospital.Shehasstudiedthementalfunctioningofagingpersonforseveralyears.
简介:Ashopkeeperwhosellsgoodsformorethanwhathepaidforthemmakesaprofitonthetransaction.Ontheotherhand,onewhosellsgoodsforlessthanwhathepaidforthemmakesalossonthetransaction.Theprofit(orloss)madeonatransactionisoftenexpressedasapercentageofthecostprice(ie.thepricepaidbytheshopkeeperfortheitem).
简介:TheanalysisofcelllossratesinanATMMuxwithlossprioritiesisanimportantprobleminthe-studyoftrafficcontrolinATMnetworks.Inthispaper,thelossratesofthecellswithdifferentprioritiesinanATMMuxareanalyzedbyapproximatingtheactualinputprocesswithtwo-stateMMDPandfluidflowtechnique,andtheanalyticalexpressionsoftherelationbetweenthelossratesandthebuffersizeareobtained.Simulationshowsthattheapproachissullicientlyaccurateforapplications.
简介:n2000,theauthorscollectedagreatquantityofrelevantdatabyinvestigatingmorethan50naturereserves.BasedontheanalysisofdevelopmentandmanagementsituationoftheprotectedareasinChina,themainproblemswereputforward,suchas,nounifiedmanagementforincomeandmanagingactivities,lackofspecialguidelineandeffectivesupervision,lackofincomeandinvestment,investingfinancialdifferenceindifferentprovinces.Alltheseproblemscausedthelackoffundsforconstruction,aswellasthedamageofresourcesandenvironment.Furthermoretheconservingactivitieshavetotransmittotheprofitsinmanyprotectedareas.Combinedwiththeseproblems,theprimarysolutionprogrammersalsowereputforward.
简介:Whetherthegenerationaffectedbythefamilyplanningwillbenefitdirectlyisthekeytotestwhetherthepolicyimplicationsarethesametocollectiveandindividual.Thereareresearchesonthefamilyplanning'sconsequencesareusuallyinthemacro-level.Inordertodiscoveryhowfamilyplanningdirectlyaffectstheindividual,thispaperusemicrodatafromChinaFamilyPanelStudies(CFPS)2010totesttheimpactoffamilyplanningonchildren'spersonalincome.Theresultsshowsthat'quantity-qualitytradeoff'hypothesisholdsonhumancapitallevelsinChina,andtheimplementationoffamilyplanningpolicyeffectivelyincreaseschildren'seducationlevel,butthesocialcapitaleffectofsiblingsisalsoreducedbythefamilyplanningpolicy.Consideringthetwokindsofeffects,thefamilyplanningpolicyhasnotsignificantlyaffectchildren'spersonalincome.