学科分类
/ 5
90 个结果
  • 简介:当一个模板代理人和丁基tetra泰坦作为一位先锋吃了,有孔的TiO_2材料的一种类型用cetyltrimethylammonium溴化物被准备。通过学习thephotocatalytic玫瑰精B相片的运动活动有一个UV-1601PCultraviolet-visible分光光度计的催化降级反应,催化降级玫瑰精B处理的相片被发现不完全对应于一阶的运动过程。根据反应现象,催化降级与有孔的TiO_2玫瑰精B处理的相片包含了二不可逆的反应。运动模型用试验性的数据被测试。

  • 标签: 光催化剂 动力学 若丹明 TIO2 染料
  • 简介:Vegetationdegradationisrelatedtothestabilityandsuccessionprocessofecologicalsystems.Thispapercombedandscreenedtherecentnationalandinternationalresearchonvegetationdegradation,anddiscussedvegetationdegradationresearchintermsofselectionofreferenceecosystemforevaluation,selectionofevaluationindexsystemandtheselectionofevaluationmethods.Atlast,thedirectionofvegetationdegradationresearchwaspredictedandprospected.

  • 标签: VEGETATION DEGRADATION EVALUATION method EVALUATION INDEX
  • 简介:Hybridbraidsofpolyglycolide(PGA)andchitosanwerepreparedbythethree-yarnbraidingmethodfromPGAandchitosanfiberbundles.Thesebraidswereinvitrodegradedbyincubatingtheminphosphatebufferedsaline(PBS)atpH7.4and37℃for5weeks.ResultssuggestedthatPGA/chitosanhybridbraidsdegradedsignificantly.ScanningelectronmicrographsshowedthatchitosanfibersinthePGA/chitosanhybridbraidwithabout750%PGAinweight(PGA75/chitosan)wereshapedintogel-likeafter5weeks,butthoseinthehybridbraidwithabout250%PGAinweight(PGA25/chitosan)didnotchange.After5weeks,theultimatetensileloadsofPGAandPGA75/chitosanbraidslostalmostcompletely,butthoseofchitosanandPGA25/chitosanbraidsremainedaround14N.ThePGA/chitosanhybridbraidswithhigherinitialultimatetensileloadwouldhavepotentialapplicationsintendon/ligamenttissuereconstruction.

  • 标签: 玻璃 退化作用 壳聚糖 混合物
  • 简介:

  • 标签:
  • 简介:FurfuralinaqueoussolutionwastreatedbyUV/O3method.Theresultsshowthattheremovalrateoffurfuralisseverelyenhancedandthesynergismphenomenonappearswhenultravioletandozonearepresenttogether.TheinfluencesofexperimentalparameterssuchaspH,theintensityoflightandthenegative-positiveionsonfurfuraldegradationwereinvestigated.Theresultsindicatethatfurfural(300mg/L)isalmostcompletelydegradedafter3hundertheoptimumconditions.TheintermediateinthefurfuraldegradationwascharacterizedbyGC-MSandIRspectrumandthedegradationmechanismoffurfuralbyUV/O3technologywasproposed.

  • 标签: 全降解 糠醛 技术 协同作用 实验参数 光照强度
  • 简介:N-nitrosaminesarestrongcarcinogensforhumans.Thispapergivesanoverviewofthenitrosmainesincigarettesmokeincludingtheformation,theharmfulness,theanalyticalmethodsofthenitrosmainesandtheadsorptionsanddegradationsofN-nitrosamines.

  • 标签: N-亚硝酸 烟草 解析方法 吸附降解
  • 简介:Anewpreparationmethodhasbeendevelopedforthermallystableporouspolyimidemicrospheres.Porouspolyimidemicrosphereswerepreparedusingtriblockcopolymersthatconsistedofathermallystablepolyimidederivedfrompyromelliticdianhydride/4,4’-oxydianilineasthecontinuousphaseandathermallylabilepolyetherasthedispersedphase.Spheresofcopolymersweregeneratedinanonaqueousemulsionandthengraduallyheatedtocompletetheimidizationtoformamicrophase-separatedstructure.Subsequently,thermaltreatmentataslightlyreducedpressureremovedthelabileblocksandproducedpores.Undersuitabledecompositionconditions,theporesizeoftheporouspolyimidewasintherangeof200-400nm.

  • 标签: 嵌段共聚物 聚酰亚胺 制备方法 多孔质 微球 热降解
  • 简介:Boththeoreticalandfieldobservationswereexaminedtostudythecloserelationshipbetweensoildegenerationandtheevolutionofgrasslandvegetation.Ageneraln-speciesmodelofequalcompetitionunderdifferentdegreesofsoildegradationwasappliedtofielddatainordertoprobethedynamicprocessesandmechanismsofvegetationevolutionduetotheeffectsofthesoil'secologicaldeteriorationongrasslandvegetation.Comparisonsweremadebetweenthetheoreticalresultsandthepracticalsurveyswithsatisfactoryresults.

  • 标签: 草原演化 数字仿真 土壤退化 环境测试
  • 简介:Forthelargenumberofnonlineardegradationdevicesexistinginaproject,theexistingmethodshavenotsystematicallystudiedtheeffectsofrandomeffectontheremaininglifetime(RL),theaccuracyandefficiencyoftheparametersestimationarenothigh,andthecurrentdegradationstateofthetargetdeviceisnotaccuratelyestimated.Inthispaper,anonlinearWienerdegradationmodelwithrandomeffectisproposedandthecorrespondingprobabilitydensityfunction(PDF)ofthefirsthittingtime(FHT)isdeduced.Aparameterestimationmethodbasedonmodifiedexpectationmaximum(EM)algorithmisproposedtoobtaintheestimatedvalueoffixedcoefficientandthepriorivalueofrandomcoefficientinthemodel.Theposteriorvalueoftherandomcoefficientandthecurrentdegradationstateoftargetdeviceareupdatedsynchronouslybythestatespacemodel(SSM)andtheKalmanfilteralgorithm.ThePDFofRLwithrandomeffectisdeduced.AsimulationexampleisanalyzedtoverifythattheproposedmethodhastheobviousadvantageovertheexistingmethodsinparameterestimationerrorandRLpredictionaccuracy.

  • 标签: REMAINING lifetime(RL)prediction NONLINEAR DEGRADATION model WIENER
  • 简介:这研究的目的是表明杆菌SP3的基本特征并且在不同原油上评估它的效果。紧张SP3是在华东从Shengli油田的一座水库被孤立的能动的、克积极的、生产孢子的杆。紧张SP3的Thecells在5.5-8.5的氢指数范围在高温度成长了直到58℃。grewfacultatively拉紧SP3并且能使用不同器官的底层,并且生产一些代谢物如此的as4-hydroxy-4-methyl-2-pentanone,methyl-2-nitrogen苯并且1,2-benzenedicarboxylic酸bisest嗯。实验室研究证明了紧张变换了并且降级不同部件并且变化物理并且原油的化学性质。紧张SP3降级了原油和原油上的细菌的生长导致了芳香的烃,树脂和沥青质的损失。原油的简历变换将在更轻的烃和全面再分配导致丰富浸透烃。有原油的微生物的相互作用是可变的,取决于微生物引起的种类和原油的化学成分。

  • 标签: 芽孢杆菌SP3 原油 生物转化 生物降解
  • 简介:PLAispresentlyconsideredasthemostattractivecompoundfortemporarytherapeuticapplicationinthebiomedicalfield.Inthispaperwegiveanoverviewofthepresentknowledgeonthedegradationbehavior,processingtechnologyofPLAanditsapplicationinthefixationofbonefracture.

  • 标签: 骨架材料 聚交酯 降解 骨折固定应用
  • 简介:Polybenzylglutamateasoneofpolyα-aminoacidsdisplayingexcellentbiocompatibilityandbiodegradabi-lityiscapableofreactingwithhydroxyalkyl-aminebyaminolysisandchangingthebenzylglutamatetohydro-xyalkylglutamine,whichpropertiescanobviouslybeimproved.

  • 标签:
  • 简介:这研究的主要目的是在伊拉克的南部的部分的一个代表性的区域在最后20年期间加亮环境变化指示物(Basrah省作为一个盒子被拿)可伸缩理解用印射的1:250000导致了普遍环境降级现象的主要原因。遥感和GIS软件被用来分类Landsat在1990的TM和在进五的2003形象的LandsatETM+打使用和陆地盖子(LULC)班:植被土地,沙陆地,城市的区域,闲置的陆地,和水身体。监督分类和规范的差别植被索引(NDVI),规范的差别逐渐增加索引(NDBI),规范的差别水索引(NDWI),规范的差别咸度索引(NDSI),并且表层土谷物尺寸索引(GSI)在这研究被采用并且分别地过去常检索它的班边界。结果在植物的盖子(514.9km2)和沙沙丘累积(438.6km2)的增加显示出清楚的恶化,为10.1,和10.6%的财务,分别地全部的学习区域。另外,在水身体区域的减少被检测(228.9km2)。沙区域累积在全部的学习区域增加了,与年度增加扩大率(33.7km2???????????吗??

  • 标签: 环境降级 LULC RS GIS 分类索引
  • 简介:LanddegradationisoneofthesignificantenvironmentalproblemsinbothChinaandCanada,whichseriouslythreatensthesustainabledevelopmentofnationaleconomyandsocietyofbothcountries.Thispaperintroducedsomepolicies,regulationsanddepartmentcoordinationmechanismsoflandresourcemanagement,restoration/rehabilitationofdegradedland,forestresourcesmanagement,agriculturalenvironmentalprotectionandmineralarealandreclamationinCanada.Somepractices,experiencesandeffectsinlanddegradationcontrolofCanadawerelistedandanalyzed.Finally,itwassuggestedthatthesuccessfulexperiencesofCanadaintechnology,policyandmanagementforlanddegradationcontrolshouldbelearnedforimprovingefficiencyoflanddegradationinChina’swesternregion.

  • 标签: LAND DEGRADATION combating POLICY practice CANADA
  • 简介:

  • 标签:
  • 简介:Naturalresourcesdeterioration,environmentaldegradationandsustainableresetlementinSouthwestChinaWANGKelinChangshaInstituteofAg...

  • 标签: ENVIRONMENTAL DEGRADATION migration SUSTAINABLE development policies
  • 简介:一张新奇相片催化反应堆被开发搬迁(从水的1,1二度(4-chlorophenyl)-2,2,2-trichloroethane)(DDT)。在反应堆,cenosphere被用来支持借助于大音阶的第五音胶化做的TiO2电影。因为cenospheres与TiO2,是涂的,他们的比重稍微从原版被增加0.6∼0.8到0.8∼0.9,以便他们能在水里被推迟。与bubbler的混合操作,在反应堆的水处于一个使流体化得好的状态。反应堆的底部是一张沙过滤器床,它能被用来阻止光催化剂被失去。反应堆的一个数学模型在二个主要有影响的因素被开发了:紫外(紫外)轻紧张和光催化剂集中。与如此的一个模型一起,反应堆能更相当被设计。

  • 标签: 光催化反应器 优化模型 水口 DDT 降解 TIO2薄膜