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简介：AseriesofresearchesonthenutritionproblemsinthecultivationofChinesefirseedlingsandplantations,whicharemainlyfocusontheproblemsofseriouslanddegradationinChinesefirplantationsincontradictionwiththerapiddevelopmentoftheplantationsinChina,weresummarized.Twelveyearswastakenandmorethan30piecesofresearchpaperswerepublishedfortheresearches,whichreferstotheproblemsofgrowtheffect,physiologicaleffect,vegetationvariation,biomassaccumulation,n...

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简介：Alongwiththedevelopmentofcomputertechniques,theapplicationofcomputerinthree-dimensionalvisualizationsimulationofplantgrowthprocesshasbeenpaidmoreandmoreattention.TakingCunninghamialanceolataasanexample,themorphologicalparametersfromtheperspectiveofthevisualsimulationweredesignedandthetrees’morphologicalcharacteristicswereanalyzedbasedonthesurveydata.CombinedwithIFS(IteratedFunctionSystem)underthecontrolofthegrowthcurve,byusingObject-orienteddesignmethods,andaccordingtoAPIandmodelrenderingtechnologyprovidedbyDIRECTX9.0,athree-dimensionalvisualizationsystemonthegrowthanddevelopmentofC.lanceolataindividualtreeweredevelopedonthe.NETandDIRECTX9.0platforms,whichrealizedthestaticanddynamicthree-dimensionalvisualizationsimulation.

简介：ToaidinmanagementofCunninghamialanceolata,themaintimberspeciesinSouthernChina,itsvariationofspatialdistributionpatternwasanalyzed.ThreepermanentplotsofC.lanceolataplantationswithapproximatelythesamesiteconditions,setbyChinacontinuousforestinventoryinShunchang,Fujian,wereselected.C.lanceolatagrowthwasdividedintotwostages:youngtrees(5cm≤diameteratbreastheight(DBH)<10cm)andmaturetrees(DBH≥10cm).TheDBHandcoordinatesofeverytree(DBH≥5cm)inthepermanentplotswererecordedin2003and2008.ThefunctionL(r),improvementofRipley’sK(r),thepaircorrelationfunctiong(r),andtheuniformangleindex(W_i)wereusedtoanalyzethespatio-temporalvariationofspatialdistributionpatterns.Thethreepermanentplotshadmeanuniformangleindex(W)between0.494-0.578atlowaltitudes,0.465-0.477atmediumaltitudes,and0.426-0.601athighaltitudes.Resultsshowedthataltitudedidnotaffectthespatialdistributionpattern.TheL(r)andg(r)functioncurvesofmaturetreesweregenerallylowerthanyoungtrees’,i.e.tendtobemorerandomoruniformdistribution.Soregardlessoftheinitialdistributionofyoungormaturetrees,withthepassageoftime,therewasatendencyfortheaggregateddistributiontochangetoarandomdistribution,andarandomdistributiontochangetoauniformdistribution.

简介：ＴＨＥＷＡＴＥＲＭＥＬＯＮ－ＣＨＩＮＥＳＥＦＩＲＩＮＴＥＲＣＲＯＰＰＩＮＧＳＹＳＴＥＭ￥ＢｙＷｅｎＹｕａｎｇｕａｎｇＴｈｅｗａｔｅｒｍｅｌｏｎ－Ｃｈｉｎｅｓｅｆｉｒ（Ｃｕｎｎｉｎｇｈａｍｉａｌａｎｃｅｏｌａｔａ）ｉｎｔｅｒｃｒｏｐｐｉｎｇｓｙｓｔｅｍ...

简介：BasedonthepreviousstudyoncultivationnutritionofCunninghamialanceolataplantationsoffirstgeneration,thecultivationnutritionofC.lanceolataplantationswithmulti-generationwasstudied.Theresultsshowthattherearesignificantdifferencesinthegrowth,developmentandnutrientassimilationamongC.lanceolataplantationswithdifferentgenerationsandnutritionconditions.ThesedifferencesarecloselyrelatedtothelandfertilitydeclineofC.lanceolataplantations.Thispaperde...

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

简介：Microfibrilangle(MFA)inChinesefirwastestedbyX-raydiffractionapparatusandcalculatedbycomputersoftware.Theresultswereasfollows:MFAwascontrolledstronglybyinheritance,andtherewasnosignificantdifferenceinMFAamonginterspecies,juvenileandmaturewood.Inthelongitudinal,MFAreduceswiththeheightrisingfrom0to5.5m,especiallyintheheightsfrom0to1.5m.ThevaluesofMFAarenearlyconsistencefrom1.5to7.5m.Thevariationrangewasbetween10.82oand12.57ofrom1.5to7.5m,R2ofpowerequationachieved0.9321,andanalysisofvarianceindicatedthatthevariationofMFAwasnotsignificantfrom1.5to7.5m.TheageofthetreeshadanimportantinfluenceonMFA,consequently,thedifferenceinMFAwassignificantamongannualringsinradial,whichwasmaximalinnearpithandreducedrapidlyfromthepithtosapwood,anditsdeclinetendencywasslowbeyondtheninthannualring.MFAreachedminimumvalueatthe15thannualring,andthedifferencereachedmorethan20oandR2ofbinomialequationachieved0.7556.

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简介：Approximating-natureforestrymanagementtechniqueapplicationresearchisdevelopedinCiinninghamialanceolataplantationfor17yearsatJiuxianForestFarminSongxiCounty,FujianProvince.TheresultsshowthatthebiodiversityoftheC.lanceolataplantationwasincreasedfrom48.5±3.3to74.6±3.3afteradoptingclose-to-natureforestrymanagementtechniques.Comparedwithconventionalmanagementmethod,thetestedforest’ssoilfertilitywasimproved:thesoilmoisture-physicalpropertiesandsoilexchangepropertieswereameliorated,thesoilnutrientcontentswereincreased;theaveragebreastheight,averagetreeheight,individualvolume,Chinesefirstandvolumeandstandtotalvolumewerepromotedby9.24%-17.64%,8.61%-17.29%,27.94%-58.46%,2.38%-28.64%and8.63%-37.55%,respectively.Theworsethesiteconditions,thegreatertheeffectindexeswithclose-to-natureforestrymanagementtechniqueswereimproved.

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简介：ThedryingcharacteristicwasstudiedforplantationwoodofChinesefirandpoplar,whicharetypicalplantationwoodofsouthernandnorthernpartofChina,respectively.ThroughlO0-degree-methodthedryingcharacteristicandbasicdryingconditionweregotten,thendryingschedulewasdevelopedforpracticaldrying,theresultsshowedthatthedryingscheduleissuitableforChinesefirandpoplarplantationlumber,butshrinkageislarge.Therecommendationwasmadethatenoughdeadweightisneededtodecreaseshrinkageindryingprocess.Thedryingqualityofthetwospeciesoflumberisgoodinconventionaldryingmethod.

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简介：在JanuaryFebruary2008期间，严重的冰暴风雨在南部的中国引起了重要损坏到森林，创造华盖差距和变化土壤营养素可获得性和酶活动。为了理解在差距尺寸，在土壤环境的变化和这些变化穿上的效果之间的关系，玷污过程，我们在在在Cunninghamialanceolata的森林差距的化学、生物的性质在北广东省承受的土壤上调查了差距尺寸的效果，南部的中国。十自然地创造的差距，五大(80100m2)并且五小(3040m2),在C的看台被选择。lanceolata。大差距在010厘米土壤与小差距和邻近的盖住华盖的阴谋相比在土壤潮湿，有机物，N和P在轻传播比率和空气和土壤温度和衰落显示出重要增加。在在大、小的差距和盖住华盖的阴谋之间发现的有机物和滋养的层次的差别可能与处于环境条件的变化有关。在大差距沥滤的这显示的快速的崽分解和增加的营养素。而且，因为衰落，过氧化氢酶，酸磷酸酶和urease活动的底层在他们的土壤富饶发生在大差距。大森林差距可以有差的富饶的一个区域，减少在C以内的土壤营养素可获得性和酶活动。lanceolata看台。

简介：ＬｉｎｅａｒＰｈａｓｅＦＩＲＦｉｌｔｅｒｏｎＭｅａｓｕｒｉｎｇ３－ＤＳｕｒｆａｃｅ①ＷＡＮＧＹｕｎｓｈａｎ，ＹＡＮＧＦｕｊｕｎ，ＬＩＷｅｉ（ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙ，Ｊｉｎａｎ２５００６１，ＣＨＮ）Ａｂｓｔｒａｃｔ...

简介：阐述滤波器的频率响应的振幅、相位和群延时的相关性，频率解析度对滤波器的影响，群延时与滤波器的频率波长的关系，最小相位滤波器等问题。

简介：摘要本文分析了铁路牵引网的特点，并提出了数字滤波技术对牵引网中的频谱进行分析，对FIR滤波器进行了阻带衰减高的凯泽窗设计。根据仿真实验结果，取得了较好的效果。

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