学科分类
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6 个结果
  • 简介:研究在Kaptai水库被进行,之一最大人造东南亚洲的淡水湖,使用为钓鱼和其它决定水质量和它的适用性的现在的地位。水采样从在在五个不同地点从的0.2和0.8部分深度的水库的中间的部分对下游的viz在上游。Burburichara,Maichchari,Subolong,Basanthakum,和Rangamati。水分析证明NO3-N,K+和全部的P的集中,和根本,采样驻扎的推迟的固体在为鱼文化的推荐价值以外。Na+的集中,Ca2+,Mg2+,SO42?,Cl?,全部的溶解固体(TDS),溶解的氧()并且化学的氧需求(货到付款)在为水产业的标准以内。NO3-N的集中,SO42?,K+和全部的P没与深度显示出明确的趋势,地点象一样多雨并且旱季。浇pH,传导性,Na+和HCO3吗?内容在雨季是更低的,并且做并且在在两个的几乎所有地点更高的货到付款深度,与旱季相比。TDS的全部的固体和集中,,货到付款,Ca2+,Mg2+和Na+是更高的在在上游、减少逐渐地向在水库下游。集中并且Ca2+和pH更高并且在0.2-fractional深度的Mg2+更少比那些在在几乎所有地点的0.8-fractional深度。水库处于包含NO3-N和全部的P的高集中的mesotrophic状况,在有从在镇附近的城市的污染的过多的推迟的固体的存在的惊人地位。为由于如此的恶化在水库保护水质量采用措施是必要的。

  • 标签: 水库水质 孟加拉国 吉大港 化学需氧量 总溶解固体 磷浓度
  • 简介:Successionrulesofsoilacidityqualityoflarchplantationsinfirstrotationatdifferentdevelopmentstages,successionrulesofsoilacidityqualityofyoungstandoflarchplantationsinsecondrotationandtherelationshipbetweensoilacidityandvariousformsoforganicphosphorusandinorganicphosphoruswerestudiedinmountainousareaofeasternpartofNortheasternChina.Theresultsshowedthatactiveacidity(pHvalue)inrhizospheresoildecreasedcontinuallywithstandageincreasingfromyoungstand,half-maturestand,nearmaturestandtomaturestand,butactiveacidity(pHvalue)innon-rhizospheresoil,exchangeacidity,exchangeablealuminium,totalhydrolyticacidity,andtheratioofexchangeacidityandtotalhydrolyticacidityinrhizospheresoilandinnon-rhizospheresoilincreasedapparently;totalorganicP,moderatelyresistantorganicP,andhighlyresistantorganicPinsoildecreasedatallagestagesinlarchplantationswhensoilacidityadded.Forrhizospheresoilofallstandsoflarchplantationsatdifferentdevelopmentstages,therewaspositivecorrelationbetweenCa-P(exceptinyoungstand),Al-P(exceptinhalf-maturestand),Fe-P(exceptinnearmaturestandandmaturestand),O-P(exceptinyoungstand),andsoilactiveacidity,respectively;Forrhizospheresoil,therewasnegativecorrelationbetweenCa-P(exceptinhalf-maturestand),Al-P(exceptinyoungstand),O-P,andexchangeacidity,exchangeablealuminium,therewasalsonegativecorrelationbetweenCa-P,Al-P(exceptinyoungstandandhalf-maturestand),Fe-P,O-P,andtotalhydrolyticacidityrespectively.Forrhizospheresoil,thecorrelationcoefficientbetweenCa-P,O-Pandtotalhydrolyticaciditydecreased,respectively,asstandagesupandthatbetweenFe-Pandexchangeacidity,exchangeablealuminiumincreased,respectively,asstandagesgrew.Fornon-rhizospheresoil,therewasnotsignificantcorrelationbetweensoilacidityandvariousformsofinorganicphosphorusandorganicphosphorus,respective

  • 标签: 土壤磷类型 土壤酸度 轮作 落叶松人工林 有机磷 无机磷
  • 简介:Inordertobetterunderstandthereasonswhyeucalyptveneercheckseasilyandseverely,woodsamplesofthreeeucalyptspecieswereselected,andtheiranatomicalandphysicalpropertieswereexaminedaccordingtoconventionalmethodsandthenationalstandards.Theeffectsofvariancesincellwallthicknessofwoodfibreandvessel,anddiameterofthecelllumenaswellasthetissueratioonthequalityofplywoodveneerwereanalysed.Theresultsshowthat:1)ThereisagreatdifferenceinfibrecellwallthicknessanddiameterofthecelllumenbetweenearlywoodandlatewoodofEucalyptusdelegatensis.2)E.obliquahasahighwoodfibretissueratioandthethickestfibrecellwall,butthedifferenceinthefibrecellwallthicknessbetweenearlywoodandlatewoodisthesmallest.3)ThewoodfibretissueratioofE.regnansissmallerthanthatofE.obliqua,anditswoodfibrecellwallisthethinnestandthereisonlyaverysmalldifferenceinfibrecellwallthicknessbetweenearlywoodandlatewood.Thedifferenceinthediameterofwoodfibrecelllumenamongearlywood,transitionareaandlatewoodisalsosmall.4)E.delegatensishasthehighesttangentialshrinkagerateandradial-tangentialshrinkagerate,andE.obliquahasthelowest.Itisthevariabilityofwoodanatomicalpropertiesofthesespeciesthatcausethedifferenceintheveneershrinkage,andthenaffectsplywoodveneerquality.

  • 标签: 桉树 木材 胶合板 薄板
  • 简介:Weconductedastudytofindoutifarbuscularmycorrhizal(AM)fungi(Acaulosporascrobiculata,Scutellosporacalospora)andphosphatesolubilizingbacteria(PSB,Paenibacilluspolymyxa)inoculationeitherindividuallyorincombinationscanimproveAcaciaauriculiformisseedlinggrowth,uptakeofnutrientsandqualityinaphosphorusdeficienttropicalAlfisol.Theseedlingswereassessedforvariousgrowthandnutrientuptakeparametersafter60daysoftreatment.InoculationwithP.polymyxastimulatedmycorrhizalformation.Seedlingheight,stemgirth,taprootlength,numberofleavesandleafarea,plantdrymatterproduction,nodulation,andnodulardryweightweresignificantlyhigherforseedlingsthatwereeitherdualinoculatedortripleinoculatedcomparedtoindividualinoculationofAMfungiorPSB,anduninoculatedseedlings.DualandtripleapplicationofAMfungiandPSBalsosignificantlyimprovedthenutrientcontentsofshootsandrootsandnutrientuptakeefficiencies.ThecalculatedseedlingqualityindexesoftheAMfungiandPSBinoculatedseedlingwere25–208%higherthanuninoculatedseedlings.ThesefindingsshowthatA.auriculiformisseedlingswhendualinoculatedortripleinoculatedperformedbetterthanseedlingsinoculatedwiththemicrobesindividuallyandcomparedwithuninoculatedcontrolseedlings.Weconcludethatbioinoculationisimportantfortheproductionofhigh-qualityA.auriculiformisseedlingsintreenurseriesforplantinginnutrientdeficientsoils.

  • 标签: ARBUSCULAR MYCORRHIZAL fungi Nutrient uptake efficiency
  • 简介:TwoclonaltrialstandsofChineseFir(Cunninghamialanceolata)wereusedinthisstudy,onewas19-year-oldstandwhichincluded38clones,andtheotherwas17-year-oldstandincluding102clones.Thestatisticalanalysesshowedthattherewereverysignificantgeneticvariationsinheight,DBH,volumeandratioofheartwood(Rhw),woodbasicdensity(ρb)oftheclonesinthetwostands.Therepeatabilityofcloneswasinmediantohighlevel,andthegeneticCVwasdifferentovertheallfivetraits.Therewereverysignificantphenotypicandgeneticcorrelationsamongheight,DBHandvolume,andnegativecorrelationsamonggrowth,Rhwandρb.Theselectionmethodexperimentindicatedthatindexselectioncouldimprovevolume,Rhwandρb,showingsyntheticallysuperiorselectioneffectscomparedtoanyindividualtraitselectionmethods.

  • 标签: Chinese Fir(Cunninghamia lanceolata) CLONE WOOD quality
  • 简介:Bothofstraightandincliningpoplarclone107treewereselectedforstudyingmaterialsinthispaper.Theoptimalpulpingconditionswasestablishedbyorthogonalexperimentaldesignbothfornormalwoodandtensionwood,andthequalityofpulpingandpaper-makingbetweennormalwoodandtensionwoodwascomparedwitheachother.Finally,potentialapplicationforimprovingpaperqualityoftensionwoodthroughincreasingbeatingrevolutionswasdiscussed.Theresultshowedthattheoptimalcookingconditionfornormalwoodwasalkaliconcentration15%,thehighesttemperature164℃,timeathighesttemperature75min,andfortensionwooditwasalkaliconcentration13%,thehighesttemperature160℃,timeathighesttemperature40min.Pathcoefficientofeffectofalkaliconcentrationbothonpulpyieldandkappavaluewassignificantatdifferentlevels.Bycomparisonbetweenaverageresultofnormalwoodandtensionwoodinqualityofpulpingandpaper-making,itwasfoundthattensionwoodhadhigherpulpingyieldandlowerkappavaluethannormalwood.Furthermore,forallmechanicalpropertiesofpaper,normalwoodholdhighervaluethantensionwood,andevenneartwotimesthantensionwood,suchasburstindexandtensileindex.However,differenceoftearindexwasquitenarrow.ResultofonewayANOVAshowedthatdifferenceofburstindexandtearindexbetweennormalwoodandtensionwoodwassignificantatthe0.001level,oftearindexwassignificantatthe0.05level.Basedonobservationofcrosssurfaceofpaper,itwasassumedthatcontributionofgelatinouslayertorigidityofsinglefiberhadhamperedcollapseandcompressionoffiberduringpaperformation,whichisessentialforexertingcombinationbetweenfibersinpaper.So,mechanicalpropertiesoftensionwoodpaperweredecreasedaccordingly.However,owingtohighcellulosecontentofgelatinouslayer,tensionwoodwaseasiertopulpingthannormalwood.Mechanicalpropertiesoftensionwoodpapercouldbeimprovedbyincreasingbeatingrevolutions,

  • 标签: POPLAR clone 107 tension WOOD NORMAL