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376 个结果
  • 简介:AlterationsinDNArepair,cellcycle,andapoptoticpathwaysareoftenassociatedwithcancerriskandradiationsensitivity.IndividualswithreducedDNAdamageresponsefaceagreatersensitivitytomutagenchallenge.Interindividualvariabilityinmutagenorradiationsensitivityandincancersusceptibilitymayalsobetracedbacktopolymorphismsofgenesaffectinge.g.DNArepaircapacity[1].

  • 标签: DELAYED DNA REPAIR
  • 简介:适用的一本有限投出的杂志的短暂流动上的杂志错误排列的效果在这研究被介绍。新3D计算液体动力学(CFD)分析方法被使用。另外,在杂志适用和转子动力学的油电影的短暂液体动力学的联合伪的计算在分析被考虑。基于结构化的网孔,当杂志在一部油电影的液体动力学模拟期间移动时,为网孔运动的一条新途径被建议更新网孔体积。存在动态网孔模型提供了由流畅不对在杂志轴承的短暂的油流动合适。杂志的运动被作为负担的边界条件与计算电影压力解决忍受转子的系统的动人的方程获得。在液体动力学和转子动力学之间的数据交换被数据文件认识到。从CFD模型获得的结果与没有对齐的杂志轴承上的以前的试验性的结果一致。电影压力,油电影力量,磨擦转矩,错误排列时刻和态度角度为没有对齐并且排列的杂志轴承计算、比较。结果显示适用的表演被被失衡的刺激,和CFD方法基于技术能有效地预言的液体结构相互作用(FSI)引起的错误排列极大地影响在一个忍受转子的系统适用的一本没有对齐的杂志的短暂流动域。

  • 标签: 错误排列 短暂流动 计算液体动力学(CFD ) 液体结构相互作用(FSI ) 杂志适用
  • 简介:利用基于密度泛函的第一性原理对Zr5Te3化合物晶格常数、形成焓、弹性常数、以及电子态密度等性质进行了计算。在该研究中,为了获得Zr5Te3化合物的结构稳定性,考虑了Cr5B3、W5Si3以及Mn5Si3等三种结构类型,计算的形成焓表明:具有Cr5B3结构类型的Zr5Te3最稳定,其次是Mn5Si3型,最后才是W5Si3型。也对该化合物的电子态密度和电荷密度差进行了计算,利用徳拜模型计算了其在高温高压下的体积、体积模量、热熔以及热膨胀等的热物理性质。

  • 标签: 热物理性质 弹性性质 电子结构
  • 简介:Non-smallcelllungcancer(NSCLC)accountsfor85%oflungcancer,whichistheleadingcauseofdeathinlungcancerpatient.RoutinetreatmentofNSCLCcannoteffectivelychangethesurvivalrateofpatients,oneimportantreasonistheincreasedradioresistanceoftumorcellsafterconventionalradiotherapy.

  • 标签: IRRADIATION Suppressing RADIORESISTANCE
  • 简介:InsituhighpressureenergydispersiveX-raydiffractionmeasurementsonlayeredperovskite-likemanganateCa3Mn2O7underpressuresupto35GPahavebeenPerformedbyusingdiamondanvilcellwithsynchrotronradiation.Theresultsshowthatthestructureoflayeredperovskite-likemanganateCa3Mn2O7isunstableunderpressureduetotheeasycompressionofNaCl-typeblocks.ThestructureofCa3Mn2O7underwenttwophasetransitionsunderpressuresintherangeof0-35GPa.Onewasatabout1.3GPawiththecrystalstructurechangingfromtetragonaltgoorthorhombic.Theotherwasatabout9.5GPawiththecrystalstructurechangingformorthorhombicbacktoanothertetragonal.

  • 标签: 高压 X射线衍射 Ca3Mn2O7 钙钛矿结构 锰酸盐晶体 相变
  • 简介:Removalofcarbonylsulfide(COS)fromCO2streamissignificantfortheproductionandutilizationoffoodgradeCO2.ThisstudyinvestigatestheadsorptionperformanceofAg/NaZSM-5asadsorbentpreparedbyincipientwetnessimpregnationfortheremovalofCOSfromaCO2streaminafixed-bedadsorptionapparatus.Effectsofvariousconditionsonthepreparationofadsorbent,adsorptionanddesorptionwereintensivelyexamined.TheresultsrevealedthatCOScanberemovedtobelow1×10-9fromaCO2stream(1000ppmCOS/CO2)usingAg/NaZSM-5(10wt%AgNO3)withanadsorptioncapacityof12.86mg·g-1.Theadsorbentcanbefullyregeneratedusinghotairat450C.Theadsorptionabilityremainedstableevenaftereightcyclesofregeneration.

  • 标签: CARBONYL SULFIDE adsorption π-complexation COMPLETELY regeneration
  • 简介:Chemical-loopingcombustion(CLC)isanovelcombustiontechniquewithinherentCO2separation.Magnetite(Fe3O4)wasselectedastheoxygencarrier.Shenhuacoal(InnerMongolia,China),strawcokeandnaturalcokewereusedasfuelsforthisstudy.Influencesofoperationtemperatures,coaltoFe3O4massratios,anddifferentkindsoffuelsonthereductioncharacteristicsoftheoxygencarrierwereinvestigatedusinganatmospherethermogravimetricanalyzer(TGA).Scanningelectronmicroscopy(SEM)wasusedtoanalysethecharacteristicofthesolidresidues.Experimentalresultsshownthatthereactionbetweenthecoalandtheoxygencarrierbecomestrongatatemperatureofhigherthan800℃.Astheoperationtemperaturerises,thereductionconversionrateincreases.Atthetemperaturesof850oС,900℃,and950℃,thereductionconversionrateswere37.1%,46.5%,and54.1%respectively.However,SEMimagesshowthatatthetemperatureofhigherthan950℃,theironoxidesbecomemeltedandsintered.Thepossibleoperationtemperatureshouldbekeptaround900℃.WhenthemassratiosofcoaltoFe3O4were5/95,10/90,15/85,and20/80,thereductionconversionrateswere29.5%,40.8%,46.5%,and46.6%respectively.Withtheincreaseofcoal,theconversionrategoesup.Butthereexistanoptimalratioaround15/85.Comparisonsbasedondifferentkindsoffuelsshowthatthesolidfuelwithahighervolatileandamoredevelopedporestructureisconducivetothereductionreactivityoftheoxygencarrier.

  • 标签: 扫描电子显微镜 操作温度 固体燃料 Fe3O4 扫描电镜照片 四氧化三铁
  • 简介:采用第一性原理方法从原子尺度研究了SrTiO_3缓冲层对Pt/PbTiO_3/Pt铁电电容的极化强度和稳定性的影响。针对PbO和TiO_22种不同终端表面的PbTiO_3铁电电容,在Pt与PbTiO_3的下界面处逐层引入SrTiO_3缓冲层,研究了PbTiO_3薄膜极化性质的演化规律。结果表明,引入SrTiO_3缓冲层会不同程度地破坏PbTiO_3薄膜的极化对称性,使指向上表面的极化状态更为稳定,这对于要求双稳极化状态的铁电存储器是不利的。

  • 标签: 铁电薄膜 缓冲层 界面 极化对称性破缺
  • 简介:由中科院西安光学精密机械研究所研发的国内首台高速3D内窥OCT影像系统成功问世。该设备使用自主研发的微型光纤探头,可深人心脏病患者血管栓塞处进行光学相干断层(OCT)扫描,获得栓塞处清晰的3D内窥影像。利用该影像技术可帮助医生在心脏手术中对支架安放位置精确定位,并可帮助医生实现对病变血管形态及心脏支架置人状况进行离线直接观察,其成像速度及分辨率都远超现有的血管超声(IVUS)和心脏X光(DSA)技术,对于有效预防支架再狭窄和血栓支架的形成、实现心肌梗死的早期筛查和有效预防以及研究和评价心脏支架安全陛有革命性意义。

  • 标签: 影像系统 OCT 内窥 3D 心脏病患者 血管栓塞
  • 简介:WeinvestigatethesurfacestructureandcompositionofaYBa2Cu3Oy(YCO)thinfilmodifiedbyCF4plasmafluorination.Inadditiontotheabsorptionofhydrocarbons,chemicalreactionsoftheYBCOsurfacetakeplaceduringCF4plasmatreatment.Variousx-rayphotoelectronspectroscopicdataarereportedanddiscussed.Theexistenceofathinbarrierisconfirmed,whichhomogeneouslycoverstheedgeofthebaseYBCOfilminourinterfaceengineeringJosephsonjunction.MeasurementsofAugerelectronspectroscopicdataandtheresistanceversustemperatureindicatethatthebarrierisacontrollable-insulatinglayer.

  • 标签: 薄膜 YBA2CU3OY CF4等离子体
  • 简介:Two-dimensional(2D)materialshaveattractedgreatresearchinterestsduetotheiruniqueproperties.2DMoS2,unlikeitsbulkformwhichwidelyusedassolidlubricantandcatalyst,isofbrilliantapplicationprospectinnanoelectronicsandoptoelectrnics.Theelectronicdevicesworkinkindsofradiationenvironment.Toevaluatetheionradiationeffectsonmaterialpropertiesandstabilityofdevice,theswiftheavyionradiationeffectonsingle-layerMoS2wasstudiedinthiswork[1??2].

  • 标签: SWIFT HEAVY Ion
  • 简介:Fe_(3–x)O_4raspberryshapednanostructures/graphenenanocompositesweresynthesizedbyaone-steppolyol-solvothermalmethodtobetestedaselectrodematerialsforLi-ionbattery(LIB).Indeed,Fe_(3–x)O_4raspberryshapednanostructuresconsistoforiginalorientedaggregatesofFe_(3–x)O_4magnetitenanocrystals,ensuringalowoxidationstateofmagnetiteandahollowandporousstructure,whichhasbeeneasilycombinedwithgraphenesheets.TheresultingnanocompositepowderdisplaysaveryhomogeneousspatialdistributionofFe_(3–x)O_4nanostructuresatthesurfaceofthegraphenesheets.TheseoriginalnanostructuresandtheirstronginteractionwiththegraphenesheetsresultedinverysmallcapacityfadinguponLi+ionintercalation.Reversiblecapacity,ashighas660mAh/g,makesthismaterialpromisingforanodeinLi-ionbatteriesapplication.

  • 标签: 纳米复合材料 锂离子电池 覆盆子 石墨 FE 性能