简介:Apopulationofricebrownplanthopper(BPH)NilaparvatalugenscollectedfromapaddyfieldinHangzhouwassuccessivelyrearedonsusceptiblericeTaichungNative1(TN1)inalaboratoryfreefrominsecticidesformorethan14generations.Thechangesinsusceptibilitytoinsecticidesandecologicalfitnessondifferentresistantricevarietiesweremonitoredineachgeneration.Theresistanceratiotoimidaclopridsharplydeclinedwiththesuccessionofrearinggenerationswithoutinsecticidesfrom359.94-foldatF1to6.50-foldatF14comparedwiththesusceptiblestrain,andtheresistanceratiotochlorpyrifoswasfrom9.90-foldatF1to5.94-foldatF14.Nymphaldurationandweightsofnewlyhatchedfemaleadultsweresignificantlyaffectedbyricevariety,generationandtheirinteractions,butnymphalsurvivalwassignificantlyaffectedbythegenerationonly.Theratioofbrachypterousadultsinmaleswasaffectedbythegenerationandgeneration×varietyinteraction,whereasnodifferencewasfoundinfemales.Nymphaldurationextendedwithincreasinggenerations,andthefemalenymphaldurationwasshorterinthesusceptiblevarietyTN1thanthoseintheresistantvarietiesIR26andIR36.Inaddition,thefemaleadultweightinTN1washigherthanthoseinIR26andIR36.TheseresultsindicatedthattheresistanceoffieldBPHpopulationtoinsecticideswasreversedafterseveralgenerationsofno-exposuretoinsecticides,andtheecologicalfitnessinTN1washigherthanthoseinIR26andIR36.ThesefindingssuggestedtherationalandreduceduseofinsecticidesincombinationwiththemanipulationofresistantricevarietieswouldbeeffectiveforBPHmanagement.
简介:采用热重-微分热重技术研究了1-L-谷氨酸-1-脱氧-D-果糖的热失重和裂解温度,通过在线裂解气质联用技术分别分析研究了无氧和有氧条件下1-L-谷氨酸-1-脱氧-D-果糖在300℃、600℃、750℃和900℃四个温度的热裂解产物。研究结果表明1-L-谷氨酸-1-脱氧-D-果糖的裂解温度为161.3℃,在700℃时失重达到90.50%。无氧和有氧条件下裂解产物的种类和数量随着裂解温度升高而增多,有氧条件下裂解产物总数稍多于无氧条件,但种类有明显差异。无氧裂解和有氧裂解产物主要为酮类、吡咯类、吡啶类、呋喃类、吡嗪类、吲哚类以及少量芳香族化合物。有氧热裂解产物的香韵分析结果表明1-L-谷氨酸-1-脱氧-D-果糖裂解产物具有烘烤香、坚果香、甜香、花香、奶香等香韵。
简介:Apotexperimentwasconductedtoinvestigatetheeffectsofnitrogencontent[N1(nofertilizer),N2(0.15g?kg–1),andN3(0.3g?kg–1)]onthegrowthandthehydrauliccharacteristicsofpeachseedlingsunderdifferentsoilmoistureconditions(W1,W2andW3,inwhichthesoilwatercontentwas45%to55%,60%to70%,and75%to80%ofthefieldwatercapacity,respectively)byusingaspecializedhighpressureflowmeterwitharootchamberandacoupling,whichwasconnectedtoplantorgans.Leafareaandleafhydraulicconductivity(KL)increasedsignificantlyintheseedlingsbecauseofincreasedsoilmoistureandNcontent.KLincreasedwithleafarea.AlinearcorrelationwasdocumentedbetweenKLandleafarea.KLwashigherinthemorningandbegantodeclinesharplyafter16:00,atwhichKLdeclinedafteraninitialincrease.SoilmoistureandNcontentenhancedshoot(Ks)androot(Kr)hydraulicconductivities,therebyimprovingthelowsoilmoistureconditiontoalargeextent.KsandKroftheseedlingswerereducedby32%and27%respectivelyinN1,andby14.7%and9.4%,respectivelyinN2,andbothinW1,comparedwiththecontroltreatment.N3hadnosignificanteffectonKsandKrundersimilarconditions.LinearnegativecorrelationswereobservedbetweenKrandtheexcisedrootdiameteraswellasbetweenKsandtheshootstemdiameter.Theshoot-to-rootratioincreasedwithincreaseinNcontent.Theshoot-to-rootratioinN3wasincreasedby14.37%,comparedwithN1inW1aswellasby12%and4.39%inW2andW3,respectively.KnowledgeoftheeffectsofsoilmoistureandNfertilizeronhydrauliccharacteristicsandgrowthisimportant.Ourresultsprovidebasicguidelinesfortheimplementationofwater-savingirrigationandfertilizationmanagementofnurserystock.
简介:据对全国480个农村集贸市场畜产品和饲料价格定点监测,2014年5月份生猪产品和饲料价格均继续上涨。按农贸市场监测口径,本月猪粮比价为5.31∶1,比上月增加0.60个点。1生猪类产品价格回升全国活猪月平均价格为12.79元/kg,比上月(简称环比,下同)上涨15.0%,比上年同期(简称同比,下同)下跌0.2%。全国30个省份(自治区、直辖市)(简称省区市,下同)中,除贵州、云南、新疆3省(区)外,其他省份活猪价格普遍上涨。从区域情况来看,华东、华中地区涨幅较大,超过20%;西南地区涨幅最小,为2.9%。从价格水平来看,华东地区活猪平均价格最高,为12.98元/kg;东北地区最低,为12.62元/kg。猪肉月平均价格为20.86元/kg,环比上涨5.9%,同比下跌2.9%。全国30个省区市中,除广东、贵州、云南、新疆4省(区)外,猪肉价格普遍上涨。从区域情况来看,东北、华北地区涨幅较大,超过10.0%;西北、西南地区涨幅较小,低于1.0%。从价格水平看,西南地区猪肉平均价格最高,为21.43元/kg;东北地区最低,为19.52元/kg。仔猪月平均价格为22.99元/kg,环比上涨5.3%,同比下跌7.6%。
简介:我们使用了联合代理人改进在小麦稻草粒子和UF树脂之间的结合的能力的silane,并且调查了表面性质(wettability和表面粗糙)和用与由联合代理人内容和稻草/白杨木头粒子比率的silane影响了的白杨木头相结合的结合UF的小麦稻草(TriticumaestivumL.)做的particleboard的坚硬。我们在0,5%和10%的三个层次在稻草的四不同比率生产了一个分层的particleboard面板到白杨木头粒子(0%,15%,30%和45%小麦稻草)和silane联合代理人内容。粗糙大小,平均粗糙(R),平均数peak-to-valley高度(Rz),和根平均数平方粗糙(Rq)被使用跟踪技术的一支好尖笔在unsanded样品上测量。我们由使用连接到一个数字照相机和计算机系统的角度计获得了接触角度大小。包含白杨粒子的更大的数量的板与控制样品相比有优异坚硬并且有更低的wettability。与有的silane的更高的数量做的面板降低R<潜水艇class=“a-plus-plus”>q值。
简介:采用浸叶法测定了北京地区6个粘虫Mythimnaseparata(Walker)田间种群对5种不同类型杀虫剂的抗药性。结果表明:与相对敏感品系相比,6个田间种群对5种杀虫剂均表现出不同程度的抗性水平。其中,对氯虫苯甲酰胺(抗性倍数为1.314~4.213)、甲氨基阿维菌素苯甲酸盐(抗性倍数为1.000~4.385)和毒死蜱(抗性倍数为1.083~5.936)表现为敏感至低水平抗性;对虫螨腈(抗性倍数为1.355~20.80)和氯氟氰菊酯(抗性倍数为1.748~13.98)表现为敏感至中等水平抗性。因此,北京地区的粘虫防治应注重将氯虫苯甲酰胺、甲氨基阿维菌素苯甲酸盐和毒死蜱与虫螨腈或氯氟氰菊酯交替或轮换使用,以延缓抗药性的产生与发展。