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500 个结果
  • 简介:4学术论文的类型、组成部分及其基本要求4.1学术论文的类型按写作方法和注意事项不同,将本标准覆盖的学术论文划分为三大类:——试验研究类论文(见3.2);——应用技术类论文(见3.3);——综述类论文(见3.4)。应用技术类论文又细分为两类:——系统开发类论文(见3.3.1);——技术改进类论文(见3.3.2)。4.2学术论文的组成部分学术论文的组成部分有:——题名;——作者署名;——摘要;——关键词;——分类;——引言;——正文;——结论或结语(可选);——致谢(可选);——参考文献(可选);——注释。

  • 标签: 论文撰写 分类号 关键词 科技期刊 作者 摘要
  • 简介:地形是分幅进行管理的,林业生产常用地形采用经纬网梯形分幅法,不同比例尺的地形通过不同经度差、纬度差进行分幅,不同比例尺地形在分幅时存在相关关系,之间也存在关联,可以通过数学公式进行换算。分幅方法是建立在经纬度基础上,经纬度与之间可以换算。存在新旧两套地形编号体系,分幅方法基本相同,但编号差异较大,新旧分幅相互之间可以换算。通过对地形分幅及编号的介绍,归纳总结相互之间关系,采用数学公式进行描述,具有较强的可操作性。

  • 标签: 地形图 图幅号 经纬度 西安80坐标系 北京54坐标系
  • 简介:以杭州曲风荷景点为研究对象,以历史文献为线索,结合山水画、版画、照片、测绘图等图像资料,梳理其景观格局变迁历程,分析演变中景物间的联系,并对各时期园林发展情况进行总结。将其发展历程划分为南宋麯时期、元代至明代衰落时期、清代更址重建时期及中华人民共和国成立至今的公园化时期。认为清康熙年间曲的迁址与更名是景点发展的重要转折点,这一举动既使古老的景名得以延续,又使景点有了新的内涵和发展空间。园林建筑与环境的营造围绕"曲"这一主题展开,代表人工的"曲"与代表自然的"风荷"体现了该景点人工建筑与自然景物并重的审美主旨。通过分析整理历史图像资料对于今人了解古代园林变迁有重要帮助。

  • 标签: 风景园林 西湖 曲院风荷 变迁 图像
  • 简介:ThefuelbreakswereestablishedinsouthChinafrom1950s.Withtheactiveworkoflocalcommunitiesandstategovernment,thefuelbreakshavebeenbuiltfor398,000kilometers.Insomeareas,fuelbreaksandfirebreakshaveconstructedanetworkprimarily,suchasintheprovincesofFujian,Guangdong,Guangxi.Thefuelbreakscanpreventforestfireeffectively.Thathasbeenapprovedbyactualexamplesandburningtests.Thefuelbreaksalsobenefittheforestecosystemandenvironment.Thispapermakes...

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  • 简介:ApplicationofPRRAtotheRuralDevelopmetinChinaTXApplicationofPRRAtotheRuralDevelopmentinChinaByShenYueqinZhouGuomoYuShuquanLiMin...

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  • 简介:统计生态学与分析技术和方法的前进很快发展。这份报纸在后面的方面在中国关于统计生态学做了评论:数据收集,空间并且时间模式分析,种类丰富和种类区域关系,人口动态,种类亲密关系,社区类似和社区簇分析,和社区分类

  • 标签: STATISTICS ECOLOGY MATHEMATICAL STATISTICS
  • 简介:Nativetreesplayimportantrolesinurbanforestry,suchasadeepculturalbackground,astrongecologicaladaptability,ahighperformance-costratioandaconvenientmanagement.Butnowtherearesomedifficultiesinnativetrees'utilizationandpopularizationduetofewstudyonlandscapeplant.Inordertoseekanabnormalandartificiallandscapingandtoproduceaneffectiveresultassoonaspossible,nativeandforeignplantscanbeproperlyusedasanavailableresourcebyimprovingtheirtechnologicallevelandemphasizingnaturalbalance.ThenChineseclassiccultureandgreeneconomicscanbecombinedwithbeautifulforestrybyimplementingurbansustainabledevelopment.

  • 标签: 城市森林 城市生态系统 本土树种 生态适应性 中国
  • 简介:Organicbiocidesastimberpreservativeshavearousedmoreandmoreattention,becausemetalsaltsespeciallyarsenic,chromeandsoon,havebeensuspectedtobepoisonoustothesoilandaquaticanimals,aswellasthedisposalofpreservedtimberwastes.Therefore,anumberofeffectiveorganicbiocideshavebeenselectedtopreventwoodorbamboofromdecay,mildew,stainandsoon.Mostoftheseproductshaveenteredintothemarket.Withpeople’sincreasingawarenessoftheenvironmentalprotection,organicbiocideswilleventuallyplayimportantrolesintimberpreservationinthefuture.Thispapersummarizedthestudiesonapplicationoforganicbiocidesaswoodorbamboopreservatives,includingresistantmechanisms,commonlyappliedtypesandeffectsagainstwoodorbamboofungi,approachestodetectingtheamountoforganicbiocidesintimberandtheirinfluencesontheenvironment.Basedonthediscussionabove,theauthorspredictedthedevelopingprospectoforganicbiocidesintimberpreservation.

  • 标签: FOREST engineering ORGANIC BIOCIDE timber PRESERVATION
  • 简介:TheApplicationofaParticipatoryApproachintheImprovementofSandyPastureLandByLongZhipuYanchiCountyislocatedonthesouthwesternbord...

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  • 简介:Eucalyptusisanimportanttreespeciesontheglobalscale,andalsoitisthemodeltreeinforestgeneticresearch.Therefore,theresearchandapplicationofmolecularmarkingtechnologyinhereditybreedingofEucalyptushaveimportanttheoreticalsignificanceandpracticalvalue.ThispaperdescribedseveralmajormolecularmarkertechnologiesandtheirapplicationtohereditybreedingofEucalyptus,andprospectedthefutureapplicationandstudyofthesetechnologies.

  • 标签: MOLECULAR MARKING technology EUCALYPTUS GENETIC BREEDING
  • 简介:Alloftheplantscanbecombusted.Themechanismofforestbeltsresistanceisthatthetreespeciesweren'tliabletobeburnedcomparedwithotherplantspecies.Inthispapernewconceptsonfireresistanttreesandfuel-breakstreeswerepresented.Thefireresistancemechanismincludes3aspects,fire-resistanttreespecies,rationalconstructionforestbeltsandenvironment.Treecrownscanresistfireforwarding.Forestbeltscanformtheenvironment,whichisnoteasytofire,andalsomakefuelsdistributeddiscontinuous.Thenetworkofforestbeltshaslargeareaofconiferforestsegregated.Theidealf'ireresistanttreespecieshadbettertoembracesomecharacteristics,suchashighf'ireresistance,rationalplantingandbiologicalcharacteristics.

  • 标签: 中国 西南地区 森林火灾 耐火树种 易燃树种 防火机理
  • 简介:Ectomycorrhizae(ECM)isbecomingtheresearchhotspotbecauseitcanimproveplantnutrientcyclingandstorageandstrengthenplantresistancetoadversityanddisease.ItiswellknownthatECMcanenhanceplantresistancetosoil-borneandstemdiseases.Themechanismsmainlyinclude:planttenderrootswillbeprotectedwellbysheath;ECMcanfacilitateuptakeandtransportcapacityofnutritionandwatertorootsandincreaseplantsvigor;ECMcancontrolorblockpathogenstoinvadetrees;ECMcanactivateresistance-relatedenzymesofthehosts;italsocanformrhizospheremicrobialcolonyandestablishroot-rhizospheremicro-ecologicalenvironment.Somycorrhizaltechnologyhasbecomeoneofthemostimportantmethodsofecologicalcontrolandbiologicalcontrolofplantdiseases.ThispapersummarizestheapplicationanddevelopmentofECMinforestdiseasecontrolandalsoraisessomeideasontheirtheoryandapplicationresearchesinthefuture.

  • 标签: 林木 抗病性 菌根技术 外生菌根 抗病机理
  • 简介:Toimprovetheaccuracyandeffectivenessofforestpestsforecasting,basedoncurrentforecastmodel,integratingthedatabaseandWebGIStechnology,apracticaldesignandconstructionapproachofforestpestknowledgebasewasputforward,andtheforecastsystemonWebapplicationframeworkwasrealizedwithsatisfactoryempiricalresults.

  • 标签: WEBGIS KNOWLEDGE BASE FOREST PESTS forecasting
  • 简介:Elovich,parabolicdiffusion,powerfunctionandexponentialequationswereusedtodescribeKdesorptionkineticsof12soilsinaconstantelectricfieldofelectro-ultrafiltration(EUF),ResultsshowedthattheElovich,parabolicdiffusionandpowerfunctionequationscoulddescribeKdesorptionkineticswellowingtotheirhighcorrelationcoefficientsandlowstandarderrors;buttheexponentialequationwasnotsuitabletobeusedinthisstudyduetoitsrelativelylowcorrelationcoefficientsandrelativelyhighstandarderrors.Thisworkestablishedsuccessfullytherelationshipsbetweentheconstants(slopeorintercept)ofkineticequationsandthebarleyresponsestoKfertilizerinthemultiple-sitefieldexperimentsandK-supplyingstatusofsoilsk,theconstantsofElovich,parabolicdiffusionandpowerfunctionequationswereverysignificantlyorsignificantlycorrelatedtothesoilavailableK,relativeyieldofbarleyandKuptakeofbarleyinNPplot.ItwassuggestedthatthekineticequationconstantscouldbeusedtoestimateK-supplyingpowerofsoils.

  • 标签: 土壤钾 钾解吸附 动力学方程 方程常数 应用
  • 简介:异形.英文名称为Pleco,通称是指分类上属于鲶形目(Siluriformes),鲶形亚目(Siluroide),吸甲鲶科(Loncariidae)的鱼而言;在分类上,他们也是不容易鉴定的鱼类之一,除了幼鱼的成长会随着时间的不同而不同,就算是同一种的民鱼,雌雄间的形体.体色花纹.也是差距甚远。

  • 标签: 异形鱼 品种类型 形态特征 生活习性