简介:摘要本文旨在突出高职院校人才培养特点与培养目标,建立较为完善的创业就业教育教学体系,从而引导大学生从入学起就转变就业观念,从生涯规划到创业规划的过程引导学生主动就业,为毕业生实现高质量就业提供科学的保障。本文结合黑龙江农垦职业学院多年来开展创新创业教育的经验,为高职院校切实可行地开展创新创业教育提供了可借鉴的版本。
简介:PolycrystallinesamplesofLa12x(Sr12yAgy)xMnO3(y=0.0,0.2,0.4,0.6,1.0)werepreparedbythesolid-statereactionmethod.ThetemperaturestabilityofmagnetoresistanceandmagnetoresistanceenhancementinLa1-x(Sr1-yAgy)xMnO3systemwithbothunivalentandbivalentelementsdopedatAsiteandwithunchangedvalueofMn3+/Mn4+ratiowereexploredthroughthemeasurementsofX-raydiffractionpatterns,magnetiza-tion-temperature(M-T)curves,resistivity-temperature(q-T)curvesandmagnetoresistance-temperature(MR-T)curves.Theresultsareasfollows:therearetwopeaksintheq-TcurvesofthesampleswithAgdoping,oneiscausedbyresistancechangeduringtheparamagnetism-ferromagnetismtransition,andtheotherisfromboundary-dependentscatteringofconductionelectronsontheboundariesofgrains.ThepeakvalueofMRincreaseswithincreasingAgdopingcontent,anditincreasesfrom8.2%fory=0.2to29.6%fory=1.0underthemagneticfieldofB=0.8T;MRremainsaconstantof12%inthetemperaturerangeof218-168Kforthesamplewithy=1.0,andthetemperaturestabilityofMRisinfavorofthepracticalapplicationofMR.
简介:Themetalorganicvaporphaseepitaxy(MOVPE)growthofindiumgalliumnitride(InGaN)hasbeendiscussedindetailtowardsthefabricationofsolarcell.TheInGaNfilmwithIncontentsupto0.4aresuccessfullygrownbycontrollingthefundamentalgrowthparameterssuchastheprecursorgasflowrates,temperatureetc.TheformationofmetallicInoriginatesfromthehighervalue(0.74)oftrimethylindium/(trimethylindium+triethylgallium)(TMI/(TMI+TEG))molarratiowithlow(4100)V/Ⅲweightmolarratiowhilethelowervalue(0.2)ofTMI/(TMI+TEG)causesthephaseseparation.Itisalsonecessarytocontrolthegrowthrateandepitaxialfilmthicknesstosuppressthephaseseparationinthematerial.ThecrystallinequalityofgrownfilmsisstudiedanditisfoundtobemarkedlydeterioratedwithincreasingIncontent.ThelatticeparametersaswellasthethermalexpansioncoefficientmismatchbetweenGaNtemplateandInGaNepi-layerareprimarilyconsideredasthereasonstodeterioratethefilmqualityforhigherIncontent.ByusingIn0.16Ga0.84Nfilms,ann+-phomo-junctionstructureisfabricatedon0.65mmGaNtemplate.Forsuchadevice,theresponsetothelightillumination(AM1.5)isobservedwithanop-ncircuitvoltageof1.4Vandtheshortcircuitcurrentdensityof0.25mA/cm2.Toimprovetheperformanceaswellasincreasesolarphotoncapturing,thedeviceisfurtherfabricatedonthickGaNtemplatewithhigherIncontent.TheIn0.25Ga0.75Nn+-pjunctionsolarcellisfoundbetterperformancewithanop-ncircuitvoltageof1.5Vandtheshortcircuitcurrentdensityof0.5mA/cm2.ThisistheInGaNp-nhomo-junctionsolarcellwiththehighestIncontenteverreportedbyMOVPE.
简介:OBJECTIVE:ToevaluatetheassociationofX-raycross-complementinggroup1(XRCC1)Arg399Gln,Arg194TrpandArg280Hispolymorphismswiththeriskofglioma.DATASOURCES:AsystematicliteraturesearchofpaperspublishedfromJanuary2000toAugust2012inPubMed,Embase,ChinaNationalKnowledgeInfrastructuredatabase,andWanfangdatabasewasperformed.Thekeywordsusedwere"glioma","polymorphism",and"XRCC1orX-rayrepaircross-complementinggroup1".Referencescitedintheretrievedarticleswerescreenedmanuallytoidentifyadditionaleligiblestudies.STUDYSELECTION:Studieswereidentifiedaccordingtothefollowinginclusioncriteria:case-controldesignwasbasedonunrelatedindividuals;andgenotypefrequencywasavailabletoestimateanoddsratio(OR)and95%confidenceinterval(CI).Meta-analysiswasperformedfortheselectedstudiesafterstrictscreening.Dominantandrecessivegeneticmodelswereusedandtherelationshipbetweenhomozygousmutantgenotypefrequenciesandmutantgenefrequencyandgliomaincidencewasinvestigated.WechosethefixedorrandomeffectmodelaccordingtotheheterogeneitytocalculateORand95%CI,andsensitivityanalyseswereconducted.PublicationbiaswasexaminedusingtheinvertedfunnelplotandtheEgger’stestusingStata12.0software.MAINOUTCOMEMEASURES:AssociationofXRCC1Arg399Gln,Arg194Trp,andArg280Hispolymorphismswiththeriskofglioma,andsubgroupanalyseswereperformedaccordingtodifferentethnicitiesofthesubjects.RESULTS:Twelvearticleswereincludedinthemeta-analysis.ElevenofthearticleswereconcernedwiththeArg399Glnpolymorphismandgliomaonsetrisk.Significantlyincreasedgliomariskswerefoundonlyinthedominantmodel(Gln/Gln+Gln/ArgversusArg/Arg:OR=1.26,95%CI=1.03-1.54,P=0.02).Inthesubgroupanalysisbyethnicity,significantlyincreasedriskwasfoundinAsiansubjectsintherecessive(OR=1.46,95%CI=1.04-2.45,P=0.03)anddominantmodels(OR=1.40,95%CI=1.10-1.78,P=0.007),andhomozygotecontrast(OR=1.69,95%CI=1.17-2.45,P=0.005),bu