简介:TypeIX-rayburstsarethemostfrequentthermonuclearexplosionsinnature,resultingfromthermonuclearrunawayonthesurfaceofanaccretingneutronstar[1].Thebreakoutreaction14O(α,p)17FfromthehotCNOcyclemayhaveaprominentimpactontheburstlightcurveandburstashes[2].However,insufficientexperimentalinformationisavailabletocalculateareliable,preciserateforthisreaction[3].Weproposedtoaddresstheexperimentalinvestigationofthe14O(α,p)17FusingTimeProjectionChamber(TPC)[4].
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T<T*,氢契约比最近的邻居长坚持,建议结合的氢联网在T统治水结构<T*为T>T*,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:Thesingle-shotspiralmagneticresonanceimaging(MRI)techniquewasimplementedandoptimizedonaBrukerBiospec47/30scanner.Thetechniqueincludesthepulsesequenceforgenerationanddetectionofthek-spaceMRIsignal(freeinductiondecay(FID)),andPC-basedprogramsforthedatagridandimagereconstruction.Thetemporalresolutionis70ms(14imagespersecond),whichconsistsofadataacquisitiontimeasshortas13.7ms,aspin-echotimeof13.6msandamagnetizationrecoverytimeof43ms.Thismakesitpossibletotakereal-timeimagesofmovingobjects.Thetechniqueisdemonstratedusingapendulum(tube)filledwithwater.
简介:Ultrafastfiberlasersareingreatdemandforvariousapplications,suchasopticalcommunication,spectroscopy,biomedicaldiagnosis,andindustrialfabrication.Here,wereportthehighlystablefemtosecondpulsegenerationfromaMXenemode-lockedfiberlaser.Wehavepreparedthehigh-qualityTi3C2Txnanosheetsviatheetchingmethod,andcharacterizedtheirultrafastdynamicsandbroadbandnonlinearopticalresponses.Theobviousintensity-andwavelength-dependentnonlinearresponseshavebeenobservedandinvestigated.Inaddition,ahighlystablefemtosecondfiberlaserwithsignal-to-noiseratioupto70.7dBandcentralwavelengthof1567.3nmhasbeendelivered.Thestudymayprovidesomevaluabledesignguidelinesforthedevelopmentofultrafast,broadbandnonlinearopticalmodulators,andopennewavenuestowardadvancedphotonicdevicesbasedonMXenes.
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.