学科分类
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4 个结果
  • 简介:Fourcategoriesofglobularproteins,includingall-α,all-β,α+β,andα/βtypes,aresimplifiedastheoff-latticeHNPmodelinvolvingthesecondary-structuralinformationofeachprotein.Thepropensityofthreetypesofresidues,i.e.,H,N,andPtoformasecondarystructureisinvestigatedbasedon146proteinsamples.WefindthatPresiduesareeasytoformα-helices,whereasHresidueshaveahighertendencytoconstructβ-sheets.ThestatisticalanalysisalsoindicatesthattheoccurrenceofPresiduesisinvariablyhigherthanthatofHresidues,whichisindependentofproteincategory.Changesinbond-andnon-bondedpotentialenergiesofallproteinsamplesunderawidetemperaturerangearepresentedbycoarse-grainedmoleculardynamics(MD)simulation.Thesimulationresultsclearlyshowalinearrelationshipbetweenthebond-stretching/bendingpotentialenergyandthereducedtemperature.Thebond-torsionalandnon-bondedpotentialenergiesshowdistincttransitionswithtemperature.Thebond-torsionalenergyincreasestothemaximumandthendecreaseswiththeincreaseoftemperature,whichisoppositetothechangeinnon-bondedpotentialenergy.Thetransitiontemperatureofnon-bondedpotentialenergyisindependentoftheproteincategory,whilethatofbond-torsionalenergyiscloselyrelatedtotheproteinsecondarystructure,i.e.,α-helixorβ-sheet.Thequantitativelybonded-andsemiquantitativelynon-bondedpotentialenergyof24α+βand23α/βproteinsamplesaresuccessfullypredictedaccordingtothestatisticalresultsobtainedfromMDsimulations.

  • 标签: 球状蛋白质 潜在能量 特性模型 分子动力学模拟 温度范围 残余
  • 简介:HfO2榆树被电子横梁蒸发在BK7玻璃底层上扔。在剩余压力和HfO2电影的结构上在100度C和400度C之间退火的影响被学习。系列,剩余压力和结构的小差别在在更低的温度退火以后被获得,这被发现。在在更高的温度退火以后,系列变到短波长,有增加退火的剩余压力增加温度。同时,雏晶尺寸增加,interplanardistance减少。光系列和剩余应力的变化对应于退火导致的结构的进化。

  • 标签: 退火 余力 氧化铪 薄膜
  • 简介:WehavestudiedtheangularmagnetoresistanceofironpnictidesBaFe2-xNixAs2,whichshowsclear180degreeperiodicityasfittedbyacosinefunction.Inthex=0.065sample,thephaseofthetwo-foldsymmetrychanges90degreesabovethetetragonal-to-orthorhombicstructuraltransitiontemperatureTs.Sincethephaseatlowtemperatureisassociatedwiththerotationoforthorhombicdomainsbymagneticfield,weshowthatevenvacuumgreasecanpushthepresenceoforthorhombicdomainsattemperaturesmuchhigherthanTs.Ourresultssuggestthatresidualstressmayhavesignificanteffectsinstudyingthenematicordersanditsfluctuationsinironpnictides.

  • 标签: 残余应力 磁电阻 转变温度 函数拟合 斜方晶系 周期性
  • 简介:Theresultsonadissociationbehaviorofpropanehydratespreparedfrom'drywater'andcontainedunreactedresidualwaterintheformoficeinclusionsorsupercooledliquidwater(watersolutionofgas)werepresentedfortemperaturesbelow273K.Thetemperaturerampingorpressurereleasemethodwasusedforthedissociationofpropanehydratesamples.Itwasfoundthatthemechanismofgashydratedissociationattemperaturesbelow273Kdependedonthephasestateofunreactedwaterinthehydratesample.Gashydratesdissociatedintoiceandgasiftheiceinclusionswereinthehydratesample.Thesamplesofpropanehydrateswithinclusionsofunreactedsupercooledwateronly(withouticeinclusions)dissociatedintosupercooledwaterandgasbelowthepressureofthesupercooledwater-hydrate-gasmetastableequilibrium.

  • 标签: 天然气水合物 分解机制 分解行为 水分解 残留水 反应