简介：土壤体积密度的测量为理解土壤的物理、化学、生物的性质是重要的。精确、快速的土壤体积密度测量技术在农业试验性的研究起一个重要作用。这评论是存在测量方法的一篇全面摘要并且为未来开发评估他们的优点，劣势，错误的潜在的来源，和方向。这些技术能广泛地作为直接、间接的方法被分类。直接方法包括核心，土块，和挖掘采样，而间接方法包括放射和回归途径。核心方法最广泛地被使用，但是为采样使用多重土壤深度耗时、困难。coring柱体的尺寸使用了，操作员经验，采样深度，并且在原处显著地玷污潮湿内容影响它的精确性。土块方法是合适的因为有重黏土的使用，和它的精确性依赖于设备刻度，弄干时间，和操作员经验，但是这个过程复杂、耗时。挖掘技术最通常被用来评估森林土壤的体积密度，但是把他们不能与大毛孔在土壤被使用，他们的测量精确性被土壤质地和分析的类型强烈影响的主要限制选择。间接方法看起来比直接途径有更大的精确性，但是有更高的费用，是更复杂的，并且要求更大的操作员经验。一如此的途径使用gamma放射，和它的精确性被土壤深度强烈影响。当他们能做间接大小，回归方法是节俭的，但是这些取决于土壤质地和有机物内容和地理、气候的性质的好、优秀数据。另外，它的精确性象大多数另外的途径一样，与采样深度减少。

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：啮齿类动物是散布了瘟疫，和Spermophilusdauricus的主要主人动物(S。dauricus)是在诺思中国的最普通的啮齿类动物。在这研究，啮齿类动物密度调查从4月在瓷器吉林省被执行到2005年8月。我和semivariogram弄弯的Morans被用来调查采样数据的空间分发特征。我们发现空间自相关索引低、失败产生一条有意义的semivariogram曲线。在这种情况中，通常使用内插器，例如kriging，不对在学习区域上印射密度合适。然而，三明治模型，基于空间成层的异质，能被用于我们的数据。我们的结果证明土壤和土地使用的类型显著地影响了啮齿类动物密度的分发，并且这些变量的交互效果独自比每个变量的强壮得多。估计三明治的啮齿类动物密度地图证明那啮齿类动物密度在吉林省从东南增加了到西北。最后，用三明治模型的啮齿类动物密度调查的一个框架被介绍。

简介：原子磁性的时刻是一个重要物理变量并且为原子模型的紧测试用作一个有用工具。为过去的十年，功能的理论和它的延期被证明了在描述原子地面状态成功并且激动的covariant密度说性质。然而，一个长期的问题是它的失败预言磁性的时刻。这篇文章在covariant密度以内在对原子磁性的时刻的描述考察最近的进步功能的理论。特别地，磁性的时刻球形奇怪--有二倍地关上的壳核心加或减一个核子的A原子核并且使变形奇怪--一原子核。

简介：Internalwavesplayacrucialroleinoceanmixing,anddensityperturbationandenergyfluxareessentialquantitiestoinvestigatethegenerationandpropagationofinternalwaves.Thispaperpresentsamethodologyforcalculatingdensityperturbationandenergyfluxofinternalwavesonlyusingavelocityfieldthatisbasedonlinearizedequationsforinternalwaves.ThemethodwastestedbynumericalsimulationsofinternalwavesgeneratedbytidalflowingoveraGaussiantopographyinastratifiedfluid.Thedensityperturbationsandenergyfluxesdeterminedusingourmethodthatonlyusedvelocitydataagreedwithdensityperturbationsandenergyfluxesdeterminedbytheequationofstatebasedontemperaturedata.Themeanrelativeerror（MRE）androotmeansquareerror（RMSE）betweenthetwomethodswerelowerthan5%and10%respectively.Inaddition,anexperimentwasperformedtoexamourmethodusingthevelocityfieldmeasuredbyParticleImageVelocimetry（PIV）,andthesetupoftheexperimentisconsistentwiththenumericalmodel.TheresultsoftheexperimentscalculatedbythemethodsusingPIVdatawerealsogenerallyequaltothoseofthenumericalmodel.

简介：Numericalsimulationsusingvolumeoffluid(VOF)methodareperformedtostudytheimpactofliquid-to-gasdensityratioonthetrajectoryofnonturbulentliquidjetsingaseouscrossflows.Inthispaper,largeeddysimulation(LES)turbulencemodeliscoupledwiththeVOFmethodtodescribetheturbulenceeffectsaccurately.Inaddition,dynamicadaptivemeshrefinementmethodwithtworefinementlevelsisappliedtorefinethesizeofthecellslocatedatgas-liquidinterface.Densityratioischangedfrom10to5000whileothernondimensionalnumbersarekeptconstant.Largedensityratiosareconsideredinthispapersincetheyarecommoninmanypracticalapplicationssuchassolutionprecursor/suspensionplasmasprays.Oursimulationsshowthatthepenetrationheight,especiallyinthefarfield,increasesasthedensityratioincreases.Ageneralcorrelationforthejettrajectory,whichcanbeusedforawiderangeofdensityratios,isdevelopedbasedonoursimulationresults.

简介：

简介：LatticeBoltzmannmethodisoneofthewidelyusedinmultiphasefluidflow.However,thetwomaindisadvantagesofthismethodaretheinstabilityofnumericalcalculationsduetothelargedensityratiooftwophasesandimpossibilityofthetemperaturedistributiontobefedbackintothevelocitydistributionfunctionwhenthetemperatureissimulated.BasedonthecombinationprescribedbyInamuro,thelargedensityratiotwo-phaseflowmodelandthermalmodelmakesthedensityratioofthemodelsimulationtobeincreasedto2778:1byoptimizingtheinterfacedistributionfunctionoftwo-phasewhichimprovestheaccuracyofdifferentialformat.Thephasetransitiontermisaddedassourcetermintothedistributionfunctioncontrollingtwophaseorderparameterstodescribethetemperatureeffectonthegas-liquidphasetransition.Thelatentheatgeneratedfromthephasechangeisalsoaddedasasourcetermintothetemperaturedistributionfunctionwhichsimulatesthemovementoftheflowunderthecommoncouplingofdensity,velocity,pressureandtemperature.Thedensityandthetemperaturedistributionofsinglebubblearesimulated.Comparisonofthesimulationresultswithexperimentalresultsindicatesagoodagreementpointingouttheeffectivenessoftheimprovedmodel.

简介：

简介：TheEmeishanlargeigneousprovince(hereafternamedbyitsacronymELIP)isthefirstacceptedlargeigneousregioninChina.Thecurrentstudytriestoreconstructthedensitystructureofthecrustinthisregion.Forthispurpose,weconductedthegravitysurveyalongan800-km-longprofile,whichstretchedlaterallyalongthelatitude27°NfromLijiang(Yunnanprovince)toGuiyang(Guizhouprovince).Thefieldworkincluded338gravitymeasurementsdistributedfromtheinnerzonetotheouterzoneofthemantleplumehead.Afteraseriesofgravityreductions,wecalculatedtheBouguergravityanomalyandthenconstructedthedensitymodelforELIPbyiterativeforwardmodelingfromaninitialdensitymodeltightlyconstrainedbywide-angleseismicreflectiondata.ThetopographyoftheMoho,herephysicallyinterpretedasadensitydiscontinuityof~0.4g·cm–3,graduallyrisesfromtheinnerzone(~50kmdeep)totheouterzone(~40km),describesathickercrustintheinnerzonethaninanyothersegmentoftheprofileandlargelyreproducestheshapeoftheBouguergravityanomalycurve.BoththeBouguergravityandthedensitystructureshowsignificantdifferenceswithrespecttotheinnerzoneandtheothertwozonesofELIPaccordingtothecommonlyacceptedpartitionoftheEmeishanarea.Athickeranddensermiddle-lowercrustseemstobethemainfeatureofthewesternsectionoftheprofile,whichislikelyrelatedtoitsmaficmagmaticcompositionduetomagmaticunderplatingofthePermianmantleplume.

简介：Inthispaperwereviewthedesignanddevelopmentofa100J,10Hznanosecondpulsedlaser,codenamedDiPOLE100X,beingbuiltattheCentralLaserFacility(CLF).This1kWaveragepowerdiode-pumpedsolid-statelaser(DPSSL)isbasedonamasteroscillatorpoweramplifier(MOPA)design,whichincludestwocryogenicgascooledamplifierstagesbasedonDiPOLEmulti-slabceramicYb:YAGamplifiertechnologydevelopedattheCLF.Thelaserwillproducepulsesbetween2and15nsindurationwithprecise,arbitrarilyselectableshapes,atpulserepetitionratesupto10Hz,allowingreal-timeshapeoptimizationforcompressionexperiments.Oncecompleted,thelaserwillbedeliveredtotheEuropeanX-rayFreeElectronLaser(XFEL)facilityinGermanyasaUK-fundedcontributioninkind,whereitwillbeusedtostudyextremestatesofmatterattheHighEnergyDensity(HED)instrument.

简介：

简介：Thebubblesriseupandburstatthefreesurfaceisacomplextwo-phaseprocess.AfreeenergylatticeBoltzmannmethod(LBM)modelisadoptedinthispapertostudythisphenomenon.Theinterfacecapturingtechnique[Zhengetal.,2006]isusedtodealwiththehighdensityratioproblem.TheLaplacelawandtheair-waterinterfacecapturingabilityarevalidatedforthemultiphasemodel.Theinteractionbetweenthesinglebubbleormultiplebubblesandthefreesurfacearestudiedbythemultiphasemodel.Theforceactingonthebubbleandtheevolutionofthefreesurfaceisstudied.Meanwhile,effectoftheinitialdistancebetweentwoadjacentbubblesoninteractioneffectsofmultiplebubblesisinvestigatedaswell.

简介：

简介：

简介：

简介：锌(Zn)缺乏是限制米饭庄稼生长和产量的主要土壤限制，然而，忍耐机制的基因控制仍然糟糕被理解。这里，我们介绍了有希望的loci和候选人基因交谈忍耐给Zn缺乏并且通过协会分析识别了用一365?在多样的aus(半野的类型米饭)的K单个核苷酸多型性(SNP)标记数组面板。容忍的就职与相对稀罕的压力症状展出了更高的生长率。染色体上的二loci7和9强烈在一个山峰压力阶段在Zn缺乏下面与植物活力被联系。从一样的试验性的阴谋基于以前的microarray数据，我们加亮其表达式被重要遗传型或环境效果在Zn下面伴随的四候选人基因缺乏。网络基因本体论支持了已知的忍耐机制，例如维生素酸小径，并且也建议了光合作用基因的重要性克服Zn缺乏症状。

简介：