简介：Themechanicalpropertiesofwoodpowder/polypropy!enecompositeswithdifferentwoodparticlesizesandwoodspecieshavebeenstudied.AllofthewoodparticiesizesincreasedtheE-modulusofthecomposites.Tensiletestsshowedthatwoodpartidesizeshadanegativeeffectontheelongationatbreakandthetensilestrengthofthecompositeshasbeenimprovedwhenwoodparticlesizeswerebe(ow150μm(below100mesh).Fortheimpacttests,thewoodpartidesizeshadanegativeeffect,buttheMDFf...

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简介：Thegeneticimprovementofwoodpropertiesisoneoftheimportantmeasuresofimprovingwoodquality.Toachievethat,forestryandwoodscientistshavedoneagreatdealofresearchinexpectationtoproducemorehigh-qualitywood.Thepapersummarizestheresearchesongeneticvariationandgeneticcorrelationofwoodpropertiesandproposestheprospectstoconductthegeneticimprovementofwoodproperties.

简介：Chemicaltransformation,nutrientreleaseandchangesintheenergycontentofdecomposingrape,sunflowerandsoybeanresiduesconfinedinburiedfiberglassbagewereassessedinalaboratorystudyduringa340-dayincubationperiod.TheorganicCdecreasedbyabout70%whiletotalN,afterinitialdecay,remainedalmostconstantforeachtypeofresidue.TheNH4^+-Nwasprogressivelyoxidizedand,consequently,theNO3^-Nincreased.TheC/NrationarrowedwithlossofC.Hemicellulose,celluloseandlignindecreasedwithdifferenttrendsforeachcropresidue.Theenergycontent,wasreducedtoabout25%inrape,30%insunflowerand20%insoybeanresidues.TotalP,K,CaandMgcontentsdecreasedforeachtypeofresidueTheresultssuggestthatthethreeresiduescouldimporvethenutrientpoolofthesoil.

简介：Effectsofnon-ionicpolyacrylamide(PAM),anionicpolyacrylamide(PHP),cationicpolyacrylamide(PCAM),non-ionicpolyvinylalcohol(PVA),anionichydrolyzedpolyacrylonitrile(HPAN)andpolyethleneoxide(PEO)onthephysicalpropertiesofthreedifferentsoilstpeswerestudied.contentofwater-stableaggregateslargerthan0.25mmincreasedtovaryingextentsfordifferentsoilsandsoilconditioners,Amongthesixkindsofcondiftioners,non-ionicpolyacrylamide(PAM)wasthemosteffectiveforredsoilwhilepolyethyleneoxide(PEO)theleasteffectiveforChaosoil,redsoilandyellow-brownsoil.Water-stableaggregateswiththemolecularweightofPEOwithinacertainrange.OnlyevaporationrateofChaosoildecreasedafteraplicationofPAMandHPANtoChaosoilandredsoil.

简介：Withtheincreaseoftheutilizationofbamboo,wemustfindoutmoreinbambooproperties.AccordingtothenationalstandardGB/T15780-1995,thispaperanalyzedtheair-drieddensityandmechanicalpropertiesofMosobambooindifferentagesandstalkparts.Theresultsshowedthatboththeageandthestalkparthaveremarkableeffectsonair-drieddensityandmechanicalproperties.Theeffectofageismuchmoreprominentthanthatofstalkpart.Theperformanceshows:upper>middle>down,whichincr...

简介：ThevariabilityofmainchemicalcompositionofradialChinesefirwasstudied.Analysisofvarianceshowedthatvariancewassignificant,especiallyforholocelluloseandα-cellulose;theholocellulosecontentinheartwoodwaslowerthanthatinsapwood;thelignincontentdecreasedfromPosition1toPosition3,butincreasedgraduallyfromPosition4toPosition8;theα-cellulosecontentinheartwoodwaslowerthanthatinsapwood;andtherelativecrystallinitywas59.97%inPosition1,60.80%inPosition2,andabout42%inothers.

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简介：Massonpine(Pinusmassoniana)isoneofthemainpinespeciesinChina.Itisthemostextensivelydistributed,itisthelargestinnumber,anditsuseisextensive.ThispaperdealswiththestudysituationofthepropertyvariationofthetreeandtheeffectofexternalconditionsonitspropertiesinChina,includingpinewoodmodification(degreasing,mouldpreventionandimprovementofdimensionalstability).

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

简介：根在稳定并且加强土壤起一个重要作用。这篇文章试图学习分支的在土壤和根之间的接口的机械性质，用在实验室的撤退测试方法。有分支接口的土壤根的机械性质通过撤退力量和根滑动曲线(F-S曲线)被决定。调查24Pinustabulaeformis的结果挑选根和55P。有分支的tabulaeformis根表明了三种撤退测试失败：分叉的根，分叉的节点上的破裂失败，和撤退失败上的破裂失败。分支角度与分支在根的失败模式上有显著效果：最大的撤退力量与分支直径和分支角度的和增加了。山峰滑动和起始的力量与分支直径的和有积极关联。然而，在分支角度和起始的力量之间的关联的意义测试证明他们没有关联。布朗奇角度和分支根直径影响在根系统和土壤之间的抛锚性质。因此，与分支调查根的抛锚力学理解根加强和抛锚的机制是重要的。

简介：土壤的描述水力的性质对环境管理重要；然而，直接测量土壤勤劳、费时间、昂贵，这很好被认出水力的性质。这份报纸考察作为一个其他的工具过去常估计土壤的pedotransfer功能(PTF)的发展水力的性质在最后二十年期间。象察觉到的卫星imagery/remote一样的现代土壤调查技术在开发PTF被使用了。比作机械学的途径，在物理性质之间的实验关系和水力的性质为预言土壤收到了宽偏爱水力的性质。许多PTF能在文学基于不同参量的功能被发现。很多个研究人员追求了能描述土壤的所有类型的水保留特征的通用功能，但是没有单个功能能被称为通用尽管货车Genuchten(VG)功能是广泛地采用的大多数。大多数报导参量的PTF集中于获得水保留的参数弄弯的VG(WRC)的评价。很多个物理、词法、化学的性质在PTF被用作预言者变量。通常，回归算法/技术(统计/神经的回归)被用于校准PTF。然而，有利用数据采矿技术的报告，例如，模式识别和基因算法。精制过去常让刻度改进PTF的精确性和可靠性的数据是批评的，这被推断。包括根均方差(RMSE)，许多统计索引同意索引(d)，最大的绝对错误(我)，吝啬的绝对错误(MAE)，决心的系数(r2)和关联系数(r)，被不同研究人员使用了评估并且验证PTF。这被说服是地点特定，对PTF的研究兴趣将继续直到通用PTF被开发并且验证。在未来研究，改进了方法将被要求从存在数据库提取信息。

简介：探索研究在孟加拉国在Noakhali区域下面在Hatiya在字符Rehania和字符Nurul回教在细长的字符和字符Piya和他们的邻近的贫瘠陆地的沿海的种植园(17岁、17岁的Sonneratiaapetala)被进行在土壤性质上决定造林效果。在土壤深度010，越过三块不同陆地的1030和3040厘米剥去viz。在17岁、17岁的keora(Sonneratiaapetala)的内陆，中间和海方面种植园，土壤潮湿，粒子密度，有机物和C，全部的N，pH，可得到的P，K，Na，Ca和Mg是显著地(p≤0.05，p≤0.01，p≤0.001)更高，并且(p≤0.001)土壤咸度显著地在他们的邻近的贫瘠陆地比那降低。在在内陆的字符细长的种植园的表面土壤的土壤潮湿，粒子密度，有机物和C，全部的N，pH，土壤咸度，可得到的P，K，Na，Ca和Mg是31.09%，2.24g·cm−3,2.41%，4.14%，0.58%，7.07，0.09dS·cm−1,28.06mg·L−1,0.50，mg·L−111.5mg·L−1,3.30mg·L−1和2.7mmol·kg−1,分别地。他们为在邻近的字符Rehania贫瘠土地的一样的深度和陆地位置的相应的值是16.69%，1.25g·cm−3,0.43%，0.74%，0.25%，6.57，0.13dS·cm−1,13.07mg·L−1,0.30mg·L−1,1.4mg·L−1,0.30mmol·kg−1和0.50mg·L−1,分别地。土壤潮湿，粒子密度，有机物和C，全部的N，pH，可得到的P，K和Ca减少了，并且土壤咸度，可得到的Na和Mg在种植园向海方面从内陆增加了。尽管土壤质地没在在种植园和邻近的贫瘠土地之间的大多数土壤深度不同，沙粒子的比例是(p≤.01)显著地降低并且淤泥粒子显著地(p≤0.001)在在他们的邻�

简介：Flammabilitypropertiesofcompositesofwoodfiberandrecycledplasticwereevaluatedbytheconecalorimeterandoxygenindexchamber.Resultswereshownasfollows:1)Wood-PVCcompositeshowedworsethermalstabilityontimetoignition(TTI)andmeanheatreleaserate(MHRR),butbetterperformanceonheatreleaserate(HRR)andmeanefficientheatofcombustion(MEHC);wood-PPcompositehadbetterthermalstabilityproperties,butwasworseonotherfireperformance;2)Comparedwithwood-PVCcomposi...

简介：竹子powder/polycaprolactonecomposites(BPPC)被转矩电流计准备调查配方的效果，处理在变阻器上调节BPPC的逻辑性质。词法行为和BPPC的机械性质也被学习。结果证明合成材料的最佳配方由70%polycaprolactone组成，30%竹子根据体积搽粉，联合代理人的铝酸盐的1.6%，1.2%硬脂的酸，和到竹子的2%石蜡根据质量搽粉比率。处理条件参数的最佳为BPPC在100°C在−1和温度在50r·m作为旋转速度被决定。BPPC(包含30拷贝竹子粉末)拥有的著名界面的相容性和BPPC的机械性质。

简介：Theobjectiveofthisstudywastoinvestigatethephysicalandmechanicalperformanceofflakeboardreinforcedwithbamboostrips.Thestudyinvestigatedthreedifferentbamboostripalignmentpatternsandanexperimentalcontrol.Allpanelsweretestedinstaticbendingbothalongparallelandperpendiculartothelengthsofthebamboostrips.Internalbondstrength(IB),thicknessswelling(TS),linearexpansion(LE),andwaterabsorption(WA)werealsoexamined.Asexpected,modulusofrupture(MOR)andmodulusofelasticity(MOE)weresubstantiallygreaterforallthreeexperimentalpaneltypesascomparedtothecontrolgroup.LEwasalsoimprovedforallthreeexperimentalpanelgroups.ThebamboostripalignmentpatternshadnosignificanteffectonTS,WAandIB.ThesamplemeansforMOR,MOEandLEtestedperpendiculartothebamboostriplengthsyieldedslightlylowermeanvaluesthancorrespondingsamplestestedparalleltothebamboostripslengths.Thisdifferenceinmechanicalpropertiesislargelyattributedtolowpaneldensityinthefailurezones.

简介：Woodpropertiesfrom28trees(Populuseuramericana)selectedfromhealthyandacidraindamagedforestweremeasuredtoevaluatethepossibleimpactsonwoodqualityandutilization.Ontheheavilydamagedlocation,thepHvalueofprecipitationrangedfrom3.7-5.0,andsulfateloadingrangedfrom20-40kg·ha-2.y-1.Quantitativeandqualitativestudiesonringwidth,physicalpropertiesandmechanicalpropertiesindicatedthatchangesofwoodpropertiesbetweendiseasedandhealthypoplaroccurred.Aci...

简介：Theinfluencelawofammoniumpolyphosphate(APP)andcouplingagentsonthemechanicalpropertiesandflameretardantpropertiesofwoodpowder/PEcompositeswerestudiedbymechanicaltestandlimitedoxygenindex(LOI)test.TheexperimentalresultsshowthattheLOIofcompositesincreasedfrom18.7%to26.5%whenthecontentofAPPflameretardantwas30%,howeverthemechanicalpropertiesdecreased.ThemaleicanhydridegraftPP,titanateandsilanecouplingagentwereusedtoimprovemechanicalpropertiesofcompositesanditwasimpliedthattitanateandsilanecouplingagentcanimprovethemechanicalpropertiesofcompositesobviously.Thelimitedoxygenindexofwoodpowder/PEcompositesreached27.5%whenthecontentoftitanatewas2%.Thermogravimetricanalysis(TGA)showsthatAPPpromotedcharringandincreasedtheamountsofchar,thusprotectingtheinnermatrixandincreasedtheamountofresidualcharathighertemperature.Thetitanatecouplingagentfurtherincreasedthecharringformedandstrengthenedthethermalstability,soobviouslyincreasedtheflameretardantofcomposites.

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