简介：Thedynamicmechanicalpropertiesofwoodpowder/polypropylenecompositeswithdifferentwoodcontenttreatedanduntreatedwiththecompatibilizerhavebeenstudied.Ithasbeenfoundthatadditionofwoodpowdersandthecompatibilizercanbothimprovetheviscoelasticityofcomposites.Glasstransitiontemperature(Tg)ofappropriatewoodpowder-filledcompositesdecreased.Thevalueforthestoragemodulus(G')increasedgraduallywithincreasingwoodpowdercontent.Theadditionofthecompatibiliz...

简介：Thedynamicviscoelasticpropertiesofbambooweretestedbydynamicmechanicsanalyzer(DMA),andthemeasurementsweredoneinthetemperaturerangeof40℃to300℃atfrequenciesof3Hz.Theresultsshowedthatwiththeincreaseofirradiationdose,thedecreaseofstoragemoduluswithincreasingtemperaturebecamemoredramatically.Thedecreaseextentofstoragemoduluswasthelowestfornon-irradiatedbamboo.Twomechanicalrelaxationprocesseswereobservedforallkindsofirradiatedbamboo.Thearelaxationprocessinlowertemperaturerangewasduetoglasstransitionofhemicelluloseandlogin,whiletheβrelaxationprocessoccurredinhighertemperaturerangewasbasedonglasstransitionofcellulose.Thelosspeakstrengthofαrelaxationprocesswentupastheirradiationdoseincrease,whilethelosspeakstrengthofβrelaxationprocessbecameupfirstandthendown,whichwascausedbythechemicalreactionofthechiefcompositionofbamboo.

简介：在公孙树bilobaseeds的内乳的蛋白质多肽的动态变化被SDS页和二维的胶化电气泳动(2-DE)在种子萌芽期间学习。结果证明在公孙树biloba的内乳的80种蛋白质点是在2-DE光谱的clearobserved。蛋白质分子的重量在26的范围—52kD，和theirisoelectric点在5.8-7.8的范围。在种子萌芽期间，13类型ofproteins被降级，并且13种蛋白质被综合；7种蛋白质withdifferent分子的重量和35kD/pI6.8的等电位的点，31kD/pI6.8，29kD/pI6.8,33kD/pI6.6，33kD/pI6.4，34kD/pI7.7和31kD/pI7.7首先作为植物的storageproteins(VSP)被识别。

简介：Time-temperaturesuperpositionprinciple(TTSP)wasusedtoexaminedynamicviscoelasticpropertiesofChineseFir(Cunninghamialanceolata)woodatanextremelylowmoisturecontent(0.6%).Storagemodulusandlossfactordatawereobtainedatdifferentconstanttemperaturesrangingfrom25℃to150℃infrequencymultiplexingexperiments(0.1-20Hz).Allviscoelasticcurvesatothertemperatureswereshiftedalongthelog-frequencyaxistosuperimposethemonareferencetemperature(i.e.135℃inthisstudy)curve.Theextendedstoragemodulusandlossfactorisothermalmastercurveswereoverawiderangeoffrequency.TheshiftfactorsweredeterminedtobeafunctionoftemperatureandfittedintotheArrheniusequationwiththeleastsquaresmethod.TheresultsshowedthatthestoragemodulusdatawereexcellentlyfittedintotheArrheniusmodel,indicatingthevalidityofthemodeltocharacterizethedynamicstiffnessbehaviorofdrywoodintherangeof25-150℃usingtheTTSP.However,thetime-temperatureequivalencewasnotabletopredictthedampingproperties.

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简介：Basedonlongtermandstationaryresearch,thetemporalandspatialpatternsanddynamiclawsofsoilwatercontentinMinqindesertareawerestudied.Someresultsareasfollows:(1)ThechangeofsoilwatercontentindifferentyearsisnotobviouslyinshrubsandduneofNitrariasibiricaandTamarixramosissima,butitwasgreatinshiftingsanddune,themaximumis2.538%;(2)Theseasondynamicscanbedividedintothreestages:accumulating,consumingandstable;(3)Theverticalchangeofsoilwa...

简介：Usingthemulti-temporalLandsatdataandsurveydataofnationalresources,theauthorsstudiedthedynamicsofcultivatedlandandlandcoverchangesoftypicalecologicalregionsinChina.TheresultsofinvestigationshowedthatthewholedistributionofthecultivatedlandshiftedtoNortheastandNorthwestChina,andasaresult,theecologicalqualityofcultivatedlanddroppeddown.TheseacoastandcultivatedlandintheareaofYellowRiverMouthexpandedbyanincreasingrateof0.73km?a-1,withadepositingrateof2.1km?a-1.ThedesertificationareaofthedynamicofHorqinSandyLandincreasedfrom60.02%ofthetotallandareain1970sto64.82%in1980sbutdecreasedto54.90%inearly1990s.AstothechangeofNorthTibetlakes,thewaterareaoftheNamuLakedecreasedby38.58km2fromyear1970to1988,withadecreasingrateof2.14km2?a-1.

简介：Inordertotesttheaccuracyoftheusually-usedfixedcalibrationfactorofthecanopyscannerofLAI-2000formeasuringtheleafareaindex(LAI),aLarixprincipis-rupprechtiiplantationwaschoseninthesmallwatershedofXiangshuihelocatedattheLiupanMountainsofNingxiaHuiAutonomousRegionofNWChina,theLAIwasmeasuredinOctober2010,aperiodfromfullcanopytothetotalfallofneedles,byusingboththeLAI-2000andlitterfallcollectionmethod.Then,acomparisonwasmadebetweentheLAIvaluesdeterminedbythelitter-fallcollectionandthatcalculatedbasedonthefiguresreadfromLAI-2000andthefixedcalibrationfactor(1.49).ItshowedthattheaverageofLAImeasurementsofthe2methodswasveryclose,withadifferenceofonly5%.However,thecalculatedLAIfromLAI-2000wasobviouslyhigherthanthetruevaluesdeterminedbylitter-fallcollectionwhenthecanopywasfullofneedles;andobviouslylowerthanthetruevaluewhenthecanopywassparseafterneedlefalling.ThereasonmaybethatLAI-2000takestheprojectionoftwigsasneedles.So,adynamiccalibrationfactorisneeded,especiallyintheseasonswhentheneedleamountandthepercentageoftwigsprojectionincrownprojectionchangequickly.Therefore,astatisticrelationinaquadraticpolynomialformbetweenthe2seriesofLAIdatawaswellfitted.ThisrelationcanbeusedforamoreaccurateestimationofLAIbasedonthedatareadfromtheeasilyusedcanopyscannerslikeLAI-2000.