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500 个结果
  • 简介:Hf的加速器质谱分析要求必须提供纯度极高的HfF4样品,以便获得足够多的HfF5^-离子流来进行测量。氧同位素等杂质会导致产生HfF3O^-,HfFO2^-等无测量价值的离子流,造成HfF5^-束流强度降低,使测量能力下降。“干法”制备技术有助于获得纯度高、无氧和水等杂质的HfF4样品,从而改善加速器质谱的测量效果。

  • 标签: 干法制备 样品 加速器质谱 测量能力 质谱分析 氧同位素
  • 简介:Afacilesyntheticroutetotwoseco-eudesmane,4,5-dioxo-10-epi-4,5-seco-γeudesmane(1)and4,5-dioxo-10-epi-4,5-seco-γ-eudesmol(2)from(+)-dihydrocarvonehasbeendescribed.Avoidingexpensivereagents,thishighlyeconomicmethodespeciallysuitsforthesynthesisof4,5-seco-eudesman-typeandophianon-typesesquiterpeneswithadoublebondatposition11and12.

  • 标签: 4 5-二氧-桉叶烷 二氢香芹酮 倍半萜烯 合成方法
  • 简介:1.ThemutationbreedingofplantsIn2016,themutationmechanismofvariousplantmutantsincludingArabidopsisthaliana,Geranium,Trades-cantiauminensis,TaraxacumkoksaghyzRodinandalgaeobtainedbyheavyionbeammutationbreedingtechniqueswereinvestigated.Thegenome-wideprofilingofanArabidopsismutantnamedcivar(CarbonionbeamsInducedVariegated)wasrevealedbyusingre-sequencingandtheroughmap-basedcloningtechniques.AphenotypescreeningofArabidopsisthalianairradiatedbycarbonionbeamsbasedonhigh-throughputimagingtechniquecombiningtheprincipalcomponentanalysisandscattermatrixclusteringanalysiswasbuiltandoptimizedwhichcanscreenthevariationofplantmutantpopulations.Thepigmentcomponentsandquantitiesandexpressionprofilesofkeygenesinvolvedinanthocyaninbiosynthesisofflower-colormutantofGeraniumandleaf-colormutantofTrades-cantiauminensiswereinvestigated.MutationbreedingofTaraxacumkoksaghyzRodininducedbycarbonionbeamirradiationswhichisnotableforitsproductionofhighqualityrubberandinulinwasstarted.Inaddition,thephotosyntheticresponseofthemutantsofScenedesmusquadricaudawithalteredpigmentfeatureswereanalyzed.

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  • 简介:Anovelclassoffulgimide,(Z)-4-oxazolylfulgimide((Z)-1-benzyl-4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl)ethylidene]tetrahydropyrrole-2,5-dione),wassynthesizedbythereactionof(Z)-4-oxazolylfulgide(4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl)ethylidene]tetrahydrofuran-2,5-dione)withbenzylamine.Photochromicpropertyof(Z)-4-oxazolylfulgimidewasstudied.Comparedwith(Z)-4-oxazolylfulgide,theabsorptionmaximumofthecoloredformof(Z)-4-oxazolylfulgimideisbathochromic-shifted.Substituentsonthearylringaffecttheabsorptionmaximumoftheopenformandthecoloredformof(Z)-4-oxazolylfulgimide.

  • 标签: 合成 光变色反应 俘精酸酐 苯胺
  • 简介:Inordertoimprovethecarsalesservice4Sshopmanagementlevel,improvetheeconomicandsocialbenefitsofenterprises,incentivesareusedtoencouragetheirown4sshops.Inthispaper,throughouttherelatedanalysisofthequarterlyandannualawardsincentiveprograminlarge-scaledomesticautomobileenterprises,entropymethodwithMATLABsoftwareisappliedtoestablishthedimensionalfitfunction.Inthedataprocessing,themultiplelinearregressionfunctionintoLingosoftwareisemployedtogetthebestsolution;andClanguageisusedtorunthescreeningdataprogramthroughtheconsistencytestprograminthesensitivityanderroranalysis.Firstofall,considerthecompanytomaximizeprofitsandmaximizetheamountofcomplaintsinthestoretomaintainalowtarget;intermsofstaff,weshouldconsiderprovidingmoreincentivesforemployees;inthecustomer,theoverallsatisfaction,serviceAttitude,vehiclecleanlinessbasedshouldbeimproved.Andtwoprogramsforthemonthlyprofitandexcessprofitsofprogressiveincentivesshouldalsobeimproved.

  • 标签: ENTROPY Weight Method RELATED INDICATORS GRAY
  • 简介:Thenon-isothermaldecompositionoflead2,4,6-trinitroresorcinatemonohydrate,Pb(TNR)·H2O,wasinvestigatedbymeansofTG-DTA,DSCandIR.Thethermaldecompositionmechanismandthedissociatedkineticswerealsoinvestigated.ThekineticparameterswereobtainedfromtheanalysisoftheDSCcurvesbyintegralanddifferentialmethods.ThemostprobablekineticmodelfunctionofthedehydrationreactionofPb(TNR)·H2Owassuggestedbythecomparisonofthekineticparameters.

  • 标签: 热分解动力学 2 4 6-三硝基间苯二酚 铅化合物 一水化物
  • 简介:TheannealingbehaviorofAgnanoparticlesinsilicawithandwithoutdefectswasinvestigatedinthisstudy.SilicasampleswithandwithoutArionpre-irradiationwereimplantedwithAgionsandthenannealedattemperaturefrom300to850℃.UV-VISspectroscopyandTEMwereusedtocharacterizetheopticalabsorbancepropertyandsizedistributionofAgnanoparticles,respectively.OpticalabsorbanceresultsshowthattheabsorbanceintensityofSPR(SurfacePlasmonResonance,SPR)peakfromAgnanoparticlesinthesamplewithpre-irradiationisstrongerthaninthesamplewithoutpre-irradiation,whichindicatesthatthedefectsproducedbypre-irradiationpromptthenucleationofAgnanoparticles.Duringannealing,theSPRpeakshiftstoshortwavelengthdirection,asshowninFig.1.

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  • 简介:Solidstatenanoporesornanochannelspreparedinpolymer[1;2]andsemiconductorfilms[3]haveshowninterestingtransportphenomena,becauseoftheirdiametersatthenanoscaleandpositiveornegativechargesontheirwalls.Grapheneisanidealmaterialfordevelopingsolidstatenanoporesnotonlyduetoitsatomicscalethickness,highmechanicalstrengthandchemicalstabilitiesbutalsobecauseoftheimpermeabilityofthepristinesinglelayergraphenetoallatomsandmoleculesexceptprotons[4].AsthesingleGraphene/PET(G/PET)nanoporeistheelementarybuildingblockfornanoporousmembrane,theunderstandingandcontrolofitsindividualionictransportpropertiesarealsocrucialinproteinseparation,waterdesalination,andbio-moleculedetectionusingarraysofidenticalnanopores.Here,thesingleG/PETnanoporewassuccessfullypreparedbyusingionirradiationtechnologyandasymmetricetchingmethod[5]andthecorrespondingionictransportpropertieswereinvestigatedindetail.

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  • 简介:Itiswellknownthatelectrochemicaloxidationofanilinedissolvedinelectrolytesolutionsisaveryusefulmethodforpreparingpolyanilinefilmsonelectrodes’.However,itisverydifficultforthismethodtoprepareauniformmonolayerpolymersincelocalnucleationandgrowthofpolyme...

  • 标签: Molecular SELF-ASSEMBLY MONOLAYER POLYMER 4-AMINOTHIOPHENOL EQCM
  • 简介:本文的目的是研究如下非局部椭圆算子方程在Dirichlet边界条件下变解的存在性{-Lku=f(x,u)inΩ,u=0,inR^n/Ω,其中Ω∈R^n(n≥2)是具有光滑边界的有界区域,非线性项f满足超线性以及次临界增长条件.利用变临界点定理,证明了在更弱的条件下无穷多变解的存在性.

  • 标签: 变号临界点 非局部椭圆算子 CERAMI条件
  • 简介:4-(Succinimido)-1-butanesulfonicacidasanefficientandreusableBronstedacidcatalyzedthesynthesisofpyrano[4,3-b]pyranderivativesundersolvent-freeconditions.Thecatalystcanbepreparedbymixingsuccinimideand1,4-butanesultonethatismoresimpleandsaferthanthepreparationofsuccinimidesulfonicacid.Thismethodhastheadvantagesofhighyield,cleanreaction,simplemethodologyandshortreactiontime.Thecatalystcouldberecycledwithoutsignificantlossofactivity.

  • 标签: 吡喃衍生物 琥珀酰亚胺 无溶剂条件 酸催化剂 亚胺基 磺酸
  • 简介:Thesynthesisof(S)-2-(3-arylacrylamido)-3-{4-[2-(5-methyl-2-phenyloxazol-4-yl)ethoxy]phenyl}propanoicacidsisdescribed.TheirstructureswereconfirmedbyH-NMR.

  • 标签: 丙酸 合成方法 分子结构 核磁共振
  • 简介:新奇pyridopyrazolopyrimidinone衍生物作为潜在的PDE5禁止者被设计并且综合。目标混合物比sildenafil对人的血小板PDE5,而是更少的有势力表明了重要禁止的活动。

  • 标签: 衍生物 高分子化学 合成方法 化合物 化学活性
  • 简介:已知曲线Γ:r=r(s)的基本向量α、β、γ且曲率和挠率分别为κ、τ,本文研究了由α、β和γ所作出的曲线Γ:ρ=r+αa+b∫s0^sβds的曲率κ和挠率τ的计算问题。

  • 标签: 曲线 曲率 挠率 基本向量