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简介：Stochasticfrontierproductionfunctionapproachisadopted,93farmersampleshavebeencollected,pureefficiency,technicalefficiency,technicalchangeandscaleefficiencyandtheinstitutionalcontributionhavebeencalculated.Theresultsindicatedthatincreasingproductivityisthesolemeasurementtoreducepoverty,institutionandtechnicalchangearethetwokeyfactors.Therefore,stableinstitution,improvingtechnicalchangesarerequired.Atpresent,itisurgenttomaketechnicalprogre...

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简介：心土酸味限制根生长并且在世界的许多部分减少庄稼收益。多于氮(N)在庄稼生产使用了的化肥的一半是当前输了到环境。这研究试图在到没有为止玉米(ZeamaysL.)在N化肥的效率上调查石膏申请的效果在南部的巴西的生产。一个地实验检验了适用表面的石膏的效果(0，5，10，和15Mg哈1)和穿衣顶的铵硝酸盐(NH4没有3)(60，120，和180kgN哈玉米根长度，N举起，和谷物产量上的1)。一个温室实验用从地实验地点收集不评估3-N与适用表面的石膏沥滤，N举起，和根长度的没受到干扰的土壤列被进行(0和10Mg哈1)和穿衣顶的NH4没有3(0和180kgN哈1)。心土酸味的改善由于石膏申请，增加的玉米根生长，N举起，谷物收益，和N使用效率。到土壤表面的适用的石膏由19%-38%和N的部分因素生产率增加了玉米谷物产量(PFP由27%-38%的N)，取决于N申请率。没受到干扰的土壤列温室实验的结果证明由石膏申请的N使用效率的那改进由于从在由于增加的玉米根长度的心土的没有3-N的更高的N举起。我们的结果建议有在一个到没有为止玉米系统的石膏的那改善心土酸味能增加N使用效率，改进谷物产量，并且减少由于沥滤的没有3-N的环境风险。

简介：锁泉华的microfibrous网络由8m(dia)的3vol.%组成镍microfibers被利用了骗诱100200mdia的30vol.%。多孔的Al2O3。ZnO和CaO然后被早期的湿受精方法高度驱散到骗诱的Al2O3的毛孔表面上。由于表面区域，毛孔尺寸/粒子尺寸，热传导性，和空体积的唯一的联合，当在甲醇蒸气改过使用了时，产生microfibrous催化剂composites提供了催化的床反应和利用效率的重要改进。粗略地甲酸盐的260mL/min，包括>70%H2，<5%公司和踪迹CH4，与>97%甲醇变换，能在我们骗诱的新奇microfibrous的1cm3床卷被生产在470湩瑡潩?潰祬敭r合成的ZnO-CaO/Al2O3催化剂?鑈я鑈я8

简介：Theaimofthisinvestigationwastodefinetheeffectivenessofnon-contactdryingusingultrasonicvibrations.Diskradiatorswereusedforcarryingoutexperiments,andaspecialdryingchamberwasdesignedtoprovideresonantamplificationofultrasonicvibrations(from130to150dB).Dryingofginsengandothervegetablesdemonstratedthattheapplicationofultrasonicvibrationsreducedpowerinputsby20%incomparisonwithconvectivedrying.Italsoledtoadecreaseof6%infinalmoisturecontent,ifthedurationofdryingwasconstant.Thelevelofintensificationofultrasonicdryingwashigh(upto50gfor1kgofdryingmaterial),whichhelpedtolowerthetemperatureofthedryingagentandimprovethequalityofthedriedproducts.

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简介：我们考虑被随机的震动和生产进程本身败坏的一个生产系统的预防维护。恶化的度由分离、有限的状态被建模。震动根据一个泊松过程到达并且败坏由随机的数量的系统。每当它生产一个项目时，系统可以败坏。系统连续地被监视并且修理系统状态是否在以上是为维护的预定水平。我们由于安装，操作，和修理从产品和费用分析一生，产品数量，平均支出，和平均利润考虑收入。假定系统参数和费用的结构，用数字例子，我们在平均利润和最大化平均利润的最佳的维护水平上调查生产和吃惊到达的影响。建议模型是适用的，转弯，打，并且钻例如，机器由于生产在穿的生产任务压过程，milling。

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简介：Accordingtothestructure-basedforestmanagementtheory,theappraisalindicessystemofnaturalforestmanagementefficiencywasestablishedfromspatialutilization,speciesdiversity,constructivespeciescompetitionandtreecomposition,whichcouldbeusedtodepictstandstatus,anditsmetewandwasgiven.RelativeweightwasendowedbyTheAnalyticHierarchyProcess(AHP),andthentheconceptionofnaturalforestmanagementefficiencycomprehensiveappraisalindexwasputforwardforthefirsttimeandappliedtofourdifferentsamplingplotsofnaturalforest,threeofthemfromDongdapoforestregion,Jiaohe,Jilinprovince,andonefromBaihuaforestarea,Xiaolongshan,Gansuprovince,China.Theresultsareasfollowing:thestandstatuswasobviouslyimprovedafterbeingmanagedandplotA,Bgotamarkof"medium"whileCandDwere"perfect".Fromhightolow,thearrangementofforestmanagementefficiencycomprehensiveappraisalindexwasC>D>A>B.Thisappraisalresultabidedbythephenomenondetectedinthepracticalfield.Theforestmanagementefficiencycomprehensiveappraisalindexbroughtupinthispapercouldbetakenasawayofcomprehensivequantitativechangeofstandstatewhichdirectlyreflectstheeffortofforestmanagementandaffordsscientificbasisofnaturalforestmanagementeffort.

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简介：Background:ThiscontributionevaluatestheeffectofforeststructureandtreespeciesdiversityonplotproductivityandindividualtreegrowthintheuniqueKnysnaforestsinSouthernAfricausingmappedtreedatafromanobservationalstudythathasbeenre-measuredoveraperiodof40years.Methods:Theeffectsoftreespeciesdiversityandforeststructureontreegrowthandforestproductionareevaluatedonthreelevelsofresolution:a)theforestcommunity(canopy,sub-canopyspecies),b)thesubplots(numberoftreesperha,skewnessofthediameterdistribution,diametercoefficientofvariation)andc)theimmediateneighborhoodofselectedreferencetrees('Mingling','Dominance',Aggregation'and'SizeVariation').Results:Ananalysisofthecommunitylevelidentifiedtwodistinctclusters,oneincludingdominant/canopyspecieswiththehighestgrowthratesandagreatervariationofgrowth,andanotherclusterwhichincludestheremainingsubcanopyspecieswhichhaveasmallermaximumsizeandlowerratesofgrowth.Thearea-basedstructurevariablesonplotlevelhaveahighlysignificanteffectontotalbasalareagrowth.However,theeffectsofforestdensityandspeciesrichnessonproductivitywerenotstraightforward.Maximumbasalareaproductionofabout0.75m~2/ha/yearisachievedatmediumlevelsofrichness(around20speciesperha)andmediumlevelsofdensity(around30m~2/habasalarea)usingpercentileregressionestimates.Therelative'Dominance'ofaselectedreferencetreehadahighlysignificanteffectonindividualtreegrowthonallinvestigatedspecies.Otherneighbourhoodstructurevariableswereonlyoccasionallysignificantornotsignificantatall.Conclusion:Thiscontributionpresentsanewtheoreticalframeworkforanalysingnaturalforeststhatincludescommunity,plotandneighborhoodvariablesofforeststructureanddiversity,andafirstspecificanalysisofthestructureanddynamicsoftheKnysnaAfromontaneForest,basedonauniquesetoflongtermobservations.Thespecies-area(SAR

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简介：GansuRareEarthCorporationisoneofthelargestrareearthproducersinChina.Itsannualpro-ductioncapacityofrareearthchloridehasreached18000tonREObytheendof1992,rankingthefirstinChinaandbeingthesecondintheworld(onlynexttoMolycorp.,USA).Thecorporation’soriginalannualcapacityofrareearthchloridewas12000tonREO.Inmeeting