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简介：Adoptionofcertifiedandimprovedhigh-yieldingcropvarietiesisimportantavenueforincreasingagriculturalproductivityandimprovingthelivingstandardofthefarmersindevelopingcountries.ThemainobjectiveofthecurrentstudywastoexaminefactorsaffectingadoptionofimprovedricevarietiesbysmallholderfarmersinNorthernSindh,Pakistan.Therandomsamplingtechniquewasusedtocollectdatafrom220smallholderricefarmersthroughthefacetofaceinterview.Datawereanalyzedusingdescriptivestatisticsandprobitregressionmodel.Theempiricalresultsshowedthatyearofeducation(P≤0.093),farmingexperience(P≤0.043),soilquality(P≤0.077),farmmachineryownership(P≤0.000),accesstomarketinformation(P≤0.055)andcontactwithextensionagents(P≤0.006)hadsignificantlypositiveinfluenceonadoptionofimprovedricevariety,whileage(P≤0.053)hadsignificantlynegativeeffect.

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简介：Shallowwaterflow（SWF）,adisastrousgeohazardinthecontinentalmargin,hasthreateneddeepwaterdrillingoperations.Underoverpressureconditions,continualflowdeliveringunconsolidatedsandsupwardintheshallowlayerbelowtheseafloormaycauselargeandlong-lastinguncontrolledflows;theseflowsmayleadtocontrolproblemsandcausewelldamageandfoundationfailure.Eruptionsfromover-pressuredsandsmayresultinseafloorcraters,mounds,andcracks.Detailedstudiesof2D/3DseismicdatafromaslopebasinoftheSouthChinaSea（SCS）indicatedthepotentialpresenceofSWF.Itiscommonlycharacterizedbylowerelasticimpedance,ahigherVp/Vsratio,andahigherPoisson＇sratiothanthatforthesurroundingsediments.AnalysisofgeologicaldataindicatedtheSWFzoneoriginatedfromadeepwaterchannelsystemwithgasbearingover-pressuredfluidflowandahighsedimentationrate.WeproposedafluidflowmodelforSWFthatclearlyidentifiesitsstressandpressurechanges.TheruptureofpreviousSWFzonescausedthefluidflowthatoccurredintheBaiyunSagofthenorthernSCS.

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简介：1.ObjectivesSouthernQinghai-northemTibetpermafrostregionisaplacehavingthemostwidespreadandmostdevelopedpermafrostinChinawithgoodmineralizationconditionsandprospectingpotentialsforgashydrate(ZhuYHetal.,2011).In2011,ChinaGeologicalSurveyinitiatedaspecialnationalprogramentitled"Gashydrateresourceexplorationandtrialmining",whichsignaledapreludetoacomprehensivegashydratesurveyinsouthernQinghai-northernTibetpermafrostregion.Sofar,appreciableprogresshasbeenmadeinthegeological,geophysical,geochemicalanddrillingsurveyacrossanumberofkeyblocks.Thispaperisintendedtoexaminethefundamentalconditionsforgashydratemineralizationbasedonpreviousfindings,delineatefavorablezonesforgashydratemineralization,andtomakecontributionstotheonshoregashydrateresourceexplorationinChina.

简介：Background:Thelargepotentialofthesoilorganiccarbon(SOC)pooltosequesterCO2fromtheatmospherecouldgreatlyamelioratetheeffectoffutureclimatechange.However,thequantityofcarbonstoredinterrestrialsoilslargelydependsuponthemagnitudeofSOCmineralization.SOCmineralizationconstitutesanimportantpartofthecarboncycle,andisdrivenbymanybiophysicalvariables,suchastemperatureandmoisture.Methods:Soilsamplesofapineforest,anoakforest,andapineandoakmixedforestwereincubatedfor387daysunderconditionswithsixtemperaturesettings(5°C,10°C,15°C,20°C,25°C,30°C)andthreelevelsofsoilmoisturecontent(SMC,30%,60%,90%).TheinstantaneousrateofmineralizedSOCwasperiodicallyandautomaticallymeasuredusingaLi-CorCO2analyzer.BasedonthemeasuredamountofmineralizedSOC,carbonfractionswereestimatedseparatelyviafirst-orderkineticone-andtwo-compartmentmodels.Results:Duringthe387dayincubationexperiment,accumulativemineralizedcarbonrangedfrom22.89mgcarbon(C)·g-1SOCat30°Cand30%SMCforthemixedforestto109.20mgC·g-1SOCat15°Cand90%SMCfortheoakforest.Mineralizedrecalcitrantcarbonvariedfrom18.48mgC·g-1SOCat30°Cand30%SMCforthemixedforestto104.98mgC·g-1SOCat15°Cand90%SMCfortheoakforest,andcontributedatleast80%tototalmineralizedcarbon.Conclusions:Basedontheresultsofthisexperiment,thesoilorganicmatterofthepurebroadleavedforestismorevulnerabletosoilmicrobialdegradationinnorthernChina;mostoftheamountofthemineralizedSOCderivedfromtherecalcitrantcarbonpool.Labilecarbonfractionconstitutesonaverage0.4%ofSOCacrossthethreeforesttypesandwasrapidlydigestedbysoilmicrobesintheearlyincubationstage.SOCmineralizationmarkedlyincreasedwithsoilmoisturecontent,andcorrelatedparabolicallytotemperaturewiththehighestvalueat15°C.Nosignificantinteractionwasdetectedamongthese

简介：Multi-beambathymetryandseismicsequencesurveysinthenorthernslopeoftheSouthChinaSearevealdetailedgeomorphologyandseismicstratigraphycharacteristicsofcanyons,gullies,andmassmovements.ModerncanyonsandgulliesareroughlyelongatedNNW–SSWwithU-shapedcrosssectionsatwaterdepthsof400–1000m.Massmovementsincludeslidecomplexes,slidescars,anddebris/turbidityflows.SlidecomplexesandslidescarsareorientedintheNE–SWdirectionandcoveranareaofabout1790and926km2,respectively.Thedebris/turbidityflowsdevelopedalongthelowerslope.Adetailedfaciesanalysissuggeststhatfourseismicfaciesexist,andthelateCenozoicstratigraphyabovetheacousticbasementcanberoughlysubdividedintothreesequencesseparatedbyregionalunconformitiesinthestudyarea.Theoccurrenceofgashydratesismarkedbyseismicvelocityanomalies,bottom-simulatingreflectors,gaschimneys,andpockmarksinthestudyarea.Seismicobservationssuggestthatmoderncanyonsandmassmovementsformedaroundthetransitionbetweenthelastglacialperiodandthecurrentinterglacialperiod.Thepossibleexistenceanddissociationofgashydratesandtheregionaltectonicsettingmaytriggerinstabilityandmassmovementsontheseafloor.Canyonsmaybethefinalresultofgashydratedissociation.Ourstudyaimstocontributenewinformationthatisapplicabletoengineeringconstructionrequiredfordeep-waterpetroleumexplorationandgashydratesurveysalonganymarginalsea.

简介：Inthispaper,wetakeDLW3101coreobtainedatthetopofthecanyon(nolandslidearea)andDLW3102coreobtainedatthebottomofthecanyon(landslidearea)onthenortherncontinentalslopeoftheSouthChinaSeaasresearchobjects.ThechronostratigraphicframeworkoftheDLW3101coreandelementalstrataoftheDLW3101coreandtheDLW3102coresinceMIS5areestablishedbyanalyzingoxygenisotope,calciumcarbonatecontent,andX-RayFluorescence(XRF)scanningelements.Onthebasisoftheinformationobtainedbyanalyzingthesedimentarystructureandchemicalelementsinthelandslidedeposition,wefoundthattheDLW3102coreshowsfourlayersofsubmarinelandslides,andeachlandslidelayerischaracterizedbyhighSi,K,Ti,andFecontents,therebyindicatingterrigenousclasticsources.L1(2.15–2.44m)occurredinMIS2,whichisaslumpsedimentarylayerwithasmallslidingdistanceandscale.L2(15.48–16.00m)occurredinMIS5andisadebrisflow-depositedlayerwithascaleandslidingdistancethataregreaterthanthoseofL1.L3(19.00–20.90m)occurredinMIS5;itsupperpart(19.00–20.00m)isadebrisflow-depositedlayer,anditslowerpart(20.00–20.90m)isaslidingdepositionlayer.ThelandslidescaleofL3islarge.L4(22.93–24.27m)occurredinMIS5;itsupperpart(22.93–23.50m)isaturbidsedimentarylayer,anditslowerpart(23.50–24.27m)isaslumpsedimentarylayer.ThelandslidescaleofL4islarge.

简介：Background:Forestmanagementdecisionsarebasedonexpectationsoffuturedevelopments.Forsounddecisionsitisessentialtoaccuratelypredicttheexpectedvaluesinfuturedevelopmentsandtoaccountfortheirinherentuncertainty,forexampletheimpactofclimatechangeonforests.Changingclimaticconditionsaffectforestproduaivityandaltertheriskprofileofforestsandforestenterprises.IntensifyingdroughtstressisseenasonemajorriskfactorthreateningforestmanagementinthenorthGermanlowlands.Droughtstressreducestreegrowthandvitalityandmighteventriggermortality.Butsofar,itisnotpossibletoquantifyeffectsofapersistentdryerclimateonforestproductivityatalevelsuitableforforestmanagement.Methods:Weapplyawell-establishedsingle-treeforestgrowthsimulatortoquantifytheeffectofpersistentdryerclimatesonfutureforestproductivity.WeanalysethegrowthofScotspine(PinussylvestrisL.);Europeanbeech{FagussylvoticoL.)andoak{QuercusroburL.andQuercuspetraeo(Matt.)Liebl.)intwoforestregionsinthenorthGermanlowlandsforatimeintervalof60yearsuntil2070.Thegrowthresponseunderthreedifferentclimateprojectionsiscomparedtoabaselinescenario.Results:Theresultsshowcleardifferencesinvolumeincrementtopersistentdryerclimatesbetweentreespecies.Thefindingsexhibitregionaldifferencesandtemporaltrends.WhilemeanannualincrementatbiologicalrotationageofScotspineandoakpredominantlybenefitsfromtheprojectedclimateconditionsuntil2070,beechmightsufferlossesofupto3m3-ha’-yr1dependingonclimatescenarioandregion.However,intheprojectionperiod2051to2070theuncertaintyrangescomprisepositiveaswellasnegativeclimaticeffectsforallspecies.Conclusions:Theprojectedchangesinforestgrowthserveasquantitativecontributionstoprovidedecisionsupportintheevaluationof,forexample,speciesfuturesitesuitabilityandtimbersupplyassessments.Theanalysiso

简介：Geochemical和从北华南海的Baiyun深海的区域为钻的沉积标明日期数据的由岩屑形成的锆石U-Pb从渐新世表明沉积来源的一个变化到中新世。裂缝前的锆石年龄始新世序列与各种各样的山峰价值到Yanshanian年龄被统治(为U1435和L21的110-115妈；为H1的150妈)，从先存在的中生代magmatic带显示本地沉积供应。为在盆的北部分的渐新世沉积，稀土元素元素显示出不同分发特征，显示来自paleo-Zhujiang河(珀尔河)的沉积供应，当也在井X28由更低的渐新世阶层的多模式的锆石年龄系列证实了。由对比，一个积极Eu异例从盆的西方、南部的部分描绘沉积，显示到基本暴烈的岩石材料的从中介的潜在的起源。在渐新世的结束的Baiyun运动在深海的区域贡献了大规模沉淀，导致加深在盆的depositional环境并且另外一向北方大陆人架裂缝撤退。作为结果，从井X28，L13，和L21的上面的渐新世阶层的所有由岩屑形成的锆石年龄分享类似的分布，暗示象Zhujiang河一样的普通来源的可能的控制。在期间中新世而在北区域的沉积主要从Zhujiang河被采购，在南部的深海的区域的三角洲，和那些被基本暴烈的活动继续影响，Dongsha高举能作为主要来源作出贡献到东方区域。

简介：Liwan下垂，与4000km的一个区域，2,是之一深海在Zhujiang河(珀尔河)里下垂嘴盆，北华南海。在油和煤气的资源由探索成功启发了在深海全球下垂，我们进行了调查Liwan的tectono热的历史的热建模下垂，它广泛地被认为重要象盆的烃潜力一样理解构造活动。用多级式的有限拉长模型，构造沉淀历史和热历史为12口人工的井被获得了，它在最新在学习区域获得的一地震侧面的基础上被构造。rifting的二个阶段能从构造沉淀模式在49-33.9妈和33.9-23妈的时间时期期间被认出，并且有加热相应于rifting的过程的二个阶段。在rifting事件的结束的重建的平均基础paleo热流动价值是~70.5并且~94.2mW/m2分别地。后面的加热时期，自从23妈和基础热流动目前凉下来到~71.8-82.5mW/m2，学习区域经历了一个坚持的热变细阶段。

简介：ThemetasedimentaryLujiapuziFormationcropsoutalongthenortheasternmarginoftheNorthChinaCraton,closetotheYan-LiaoRift.Theageandtectonicsettingoftheformation,anditsrelationshipwiththeYan-LiaoRiftarecurrentlyunclear.HerewepresentdetritalzirconU-Pbages,andHfisotopicandgeochemicaldatafortheLujiapuziFormationtoconstrainthetimingofdeposition,theprovenanceoftheformation,andtheregionalstratigraphyrelationship.ZirconU-PbdatingconstrainsthetimingofdepositionoftheLujiapuziFormationtoyoungerthan1780Ma,andindicatesthatmostgrainsweresourcedfromtheLonggangBlockandthePaleoproterozoicLiao-JiBelt.DetailedfieldinvestigationsandacorrelationoftheregionalstratigraphyrevealthatmuchoftheLujiapuziFormationisequivalenttotheTuanshanziFormationintheYan-LiaoRift;thelowersectionmayrepresenttheearliestsedimentsdepositedwithintheFanheBasin.Basedontheseresultsandthefindingsofpreviousstudies,wesuggestthatthebaseoftheChangchengSystemhasanageof1.80Ga.ZirconHfisotopicdataindicatethatthemainperiodofcrustalgrowthalongthenortheasternmarginoftheNorthChinaCratonoccurredat3.2-2.5Ga,withapeakat2.9-2.7Ga.

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简介：Arbuscularmycorrhizafungi(AMF)arevitalintheregenerationofvegetationindisturbedecosystemsduetotheirnumerousecologicaladvantagesandthereforearegoodindicatorsofsoilandecosystemhealthatlarge.Thisstudywasaimedatdetermininghowtheseasonal,vegetationcoverdensity,edaphicandanthropogenicfactorsaffectAMFrootcolonization(RC)andsporedensity(SD)inDesa’adryAfromontaneforest.AMFRCandSDintherhizosphereoffivedominantwoodyspecies,Juniperusprocera,Oleaeuropaea,Maytenusarbutifolia,CarissaspinarumandDodonaeaangustifoliagrowinginDesa’aforestwerestudiedduringtherainyandthedryseasonsinthreepermanentstudyvegetationcoverdensityplots(dense,medium,andpoor).Eachplot(160×40m2)hastwomanagementpractices(fencedandunfencedplots)ofarea.A100gsampleofrhizospheresoilfrommoisturefreecompositesoilwasusedtodeterminesporedensity.Sporedensityrangedfrom50to4467spores/100gsoil,andallspecieswerecolonizedbyAMFwithinarangeof4–95%.Glomuswasthedominantgenusintherhizosphereofallspecies.VegetationcoverdensitystronglyaffectedSDandRC.TheSDwassignificantlyhigher(p<0.05)inthepoorvegetationcoverdensitythanintheothertwoandlowestinthedensecover;rootcolonizationshowedthereversetrend.Managementpracticessignificantly(p<0.05)influencedAMFSDandRC,withthefencedplotsbeingmorefavoured.Seasonssignificantly(p<0.05)affectedRCandSD.MoreRCandSDwereobservedinthewetperiodthanthedryperiod.CorrelatingAMFSDandRCwithsoilphysicalandchemicalpropertiesshowednosignificantdifference(p>0.05)exceptfortotalnitrogen.Disturbance,vegetationcoverdensity,seasonandtotalnitrogenaresignificantfactorsthatcontrolthedynamicsandmanagementinterventionstomaintaintheforesthealthofdryAfromontaneforests.

简介：Qiongdongnan盆和Zhujiang河(珀尔河)嘴盆，在北华南海的重要的含石油的盆，包含丰富的油和煤气的资源。在这研究，在在TOC内容和切的Rock-Eval参数上讨论油底泥的影响的基础上，页岩取样，作者在Qiongdongnan和Zhujiang河嘴盆的煤气的累积做了来源岩石质量，热进化和来源岩石的控制效果的全面分析。在为切页岩样品的抽取前后的TOC内容和Rock-Eval参数的对比分析显示除了Rock-Eval参数S2,油底上的更弱的影响，泥在Rock-EvalS1,Tmax和TOC内容上有某些影响。当有关对来源岩石地球化学参数，在Yacheng/Enping的页岩，Lingshui/Zhuhai和Sanya/Zhuhai的油底泥影响形成有时，主要与更好煤气的潜力和油潜力打II和III有机物。热进化分析建议油窗户的深度间隔在3000m和5000m之间。在深海的区域的来源岩石主要由于油窗户的迟了的阶段和高晚饭的成熟阶段产生了丰富的气体。弄明白的煤气的水库形成条件分析来源岩石是主要因素和差错，这是为煤气的累积的一个必要条件。来源，差错和水库的空间联合为煤气的累积和里面是必要的产生烃下垂未来潜力气体探索区域。

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简介：Post-collisionalvolcanicrocksofMesozoicageoccurintheregionsadjacenttoGerze,partofthesouthernQiangtangTerraneofnorthernTibet,China.Geochronological,geochemical,andwholerockSr-Ndisotopicanalyseswereperformedonthevolcanicrockstobettercharacterizetheiremplacementageandmodelsfortheirorigin.Laserablation-inductivelycoupledplasma-massspectrometry(LA-ICP-MS)U-Pbzirconanalysesyieldedconsistentagesrangingfrom123.1±0.94Mato124.5±0.89Maforsixvolcanicrocksfromthestudyarea.Theintermediatevolcanicrocksbelongtothealkalineandsub-alkalinemagmaseriesintermsofK2O+Na2Ocontents(5.9%–9.0%),andtotheshoshoniticandcalc-alkalineseriesonthebasisoftheirhighK2Ocontents(1.4%–3.3%).TheGerzevolcanicrocksarecharacterizedbytheenrichmentoflightrareearthelements[(La/Yb)N=34.9–49.5]andlarge–ionlithophileelements(e.g.,Rb,Ba,Th,U,K,Pb,andSr),slightlynegativeEuanomalies(Eu/Eu*=0.19–0.24),andnegativeanomaliesinhighfieldstrengthelements(e.g.,Nb,Ta,HfandTi),relativetoprimitivemantle.Thesamplesshowslightlyelevated(87Sr/86Sr)ivaluesthatrangefrom0.7049to0.7057,andlowεNd(t)valuesfrom-0.89to-2.89.Theseresultssuggestthatthevolcanicrocksstudiedderivedfromacompositionallyheterogeneousmantlesourceandthattheirparentmagmaswerebasaltic.Themoremafic,parentalmagmastotheGerzevolcanicrockslikelyunderwentfractionalcrystallizationofclinopyroxene,hornblende,biotite,andpotassiumfeldspar,duringascent,withlittletonocrustalcontamination,priortotheireruption/emplacement.Whilethesevolcanicrocksexhibitgeochemicalsignaturestypicalofmagmasformedinadestructiveplate-marginsetting,itisplausiblethattheirmantlesourcemightalsohaveacquiredsuchcharacteristicsinanearlierepisodeofsubduction.