简介：复杂系统除了受到不确定性的影响以外,还常常演化为多重时间尺度和(或)多重空间尺度。因此,相应的随机偏微分方程模型包含了时间空间上的多尺度。段金桥与王伟的新书《EffectiveDynamicsofStochasticPartialDifferentialEquations(随机偏微分方程的有效动力学)》重点研究具有快慢时间尺度及大小空间尺度的随机偏微分方程,将平均、慢流形、均匀化等基本技巧发展到随机偏微分方程中,从中萃取出有效动力学。这本书之所以提出有效动力学的原因有二:一方面,有效动力学正

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简介：Broadband（1.6–18THz）terahertztime-domainspectroscopy（THz-TDS）andtime-resolvedterahertzspectroscopy（TRTS）wereperformedona54μmthickchalcogenideglass(As30Se30Te40)samplewithatwo-colorlaser-inducedairplasmaTHzsystemintransmissionandreflectionmodes,respectively.Twoabsorptionbandsat2–3and5–8THzwereobserved.TRTSrevealsanultrafastrelaxationprocessofthephotoinducedcarrierresponse,welldescribedbyarateequationmodelwithafiniteconcentrationofmid-bandgaptrapstatesforself-trappedexcitons.ThephotoinducedconductivitycanbewelldescribedbytheDrude–Smithconductivitymodelwithacarrierscatteringtimeof12–17fs,andweobservesignificantcarrierlocalizationeffects.Afastrefractiveindexchangewasobserved100fsbeforetheconductivityreacheditsmaximum,with2ordersofmagnitudelargeramplitudethanexpectedfortheopticallyinducedTHzKerreffect,indicatingthatfreecarriersareresponsibleforthetransientindexchange.

简介：Herein,wereportthevictorioussynthesisofmetal-organicframeworks(MOFs)onTiO2nanotubes(NTs)usingalayer-by-layer(LbL)approach.HighlycrystallineandhomogenousthinfilmsofMOFsweregrownandcharacterizedusingXRD,SEM,FT-IRandUV/Visspectroscopy.Moreover,theutilizationoftheMOFfilmsassensitizerswasprobedinbespokeGraetzeltypeliquidjunctionsolarcells.TheconstructedcellperformancerevealedanIscof1.16mAcm–2,Vocof0.63V,FFof0.33,andEffof0.42%.Further,pumpprobetransientlaserspectroscopywasperformedtoinvestigatetheenergyandchargetransferdynamicsoftheMOFs/TiO2NTsinterface.Theresultsindicated86%injectionefficiency.Theultrafastpump-probespectroscopyallowstheinvestigationofthisprocessandthedifferencesbetweenMOFs.ItalsoshowedthattherelaxationoftheMOFchromophoresisincompetitionwithelectroninjectionintheTiO2motif.Thusthisstudyprovidesanewinsightintoelectrontransferfromphotoexcitedmetal-organicframeworks(MOFs)intotitaniumdioxide.

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简介：Thenatureofresistivetransitionofhigh-qualitycrystallinethinfilmsofYBa2Cu3O7-δhasbeenstudiedundermagneticfields(H)appliedalongthecdirectionoverawiderangeofdopedholes,p,intheCuO2planes.Thefield-andtemperature-dependentin-planeresistivity,ρab(T,H),hasbeenanalyzedwithinthethermallyassistedflux-flow(TAFF)formalism.Thefluxactivationenergy,U(T,H),hasbeenextractedfromthisanalysis.Thelow-Tpartoftheρab(T,H)datacanbedescribedbyanactivationenergyhavingthefunctionalformofU(T,H)=(1-t)m(H-0/H)β,wheret=T/Tc(reducedtemperature),andH0isafieldscalethatprimarilydeterminesthemagnitudeofU(T,H).Thetemperatureexponent,m,showsasystematicvariationwithp,whereasthefieldexponent,β,isinsensitivetothepvaluesandisclosetounity.TheH0,ontheotherhand,changesrapidlyaspisvaried.U(T,H)islinkedtothepinningpotentialandconsequentlyonthesuperconductingcondensationenergy.Sincethenormalstatepseudogapdirectlyaffectssuperconductingcondensationenergy,aclearcorrespondencebetweenH0andthePGenergyscale,εg,isfound.Possibleimplicationsoftheseresultsarediscussed.

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简介：古典分子的动力学模拟被执行学习高温度(在300K上面)体积水的动态行为，明确地散开系数，氢契约，和近邻居的一生的行为。二个水潜力被比较：最近建议的全球性最佳的点费用(OPC)模特儿和著名TIP4P-Ew当模特儿。由考虑计算反的散开系数和旋转松驰常数的Arrhenius阴谋，到有增加温度的一个线性趋势的从VogelFulcherTammann行为的一条转线路分别地是为OPC和TIP4P-Ew模型的检测atT*309和T*285K。试验性地，转线路点是以前观察的atT*3155K。我们也为热扩大P(T，P)，等压的P(T)曲线十字在大约一样的T*是在实验。水氢契约并且最近的邻居的一生被评估并且被发现穿过nearT*，在一生是大约1ps的地方。为TT*，水象简单液体一样更表现。事实那T*在生物学上相关的温度以内的下降变化为biomolecular系统是现象和它的可能的后果的进一步的分析的强壮的动机。

简介：QuantumdynamicscalculationsforthetitlereactionH(2S)+S2(X3-Σg)→SH(X2Π)+S(3P)areperformedbyusingagloballyaccuratedoublemany-bodyexpansionpotentialenergysurface[J.Phys.Chem.A1155274(2011)].TheChebyshevrealwavepacketpropagationmethodisemployedtoobtainthedynamicalinformation,suchasreactionprobability,initialstate-specifiedintegralcrosssection,andthermalrateconstant.Itisfoundnotonlythatthereisareactionthresholdnear0.7eVinbothreactionprobabilitiesandintegralcrosssectioncurves,butalsothatboththeprobabilityandcrosssectionincreasefirstlyandthendecreaseasthecollisionenergyincreases.Theexistenceoftheresonancestructureinboththeprobabilityandcrosssectioncurvesisascribedtothedeeppotentialwell.Thecalculationoftherateconstantrevealsthatthereactionoccurringonthepotentialenergysurfaceoftheground-stateHS2isslowtotakeplace.