简介：Inordertoimplementlarge-scaleandhigh-betatokamaksimulation,anewalgorithmoftheelectromagneticgyrokineticPIC（particle-in-cell）codewasproposedandinstalledontheGpic-MHDcode[GyrokineticPICcodeformagnetohydrodynamic（MHD）simulation].Inthenewalgorithm,thevorticityequationandthegeneralizedOhm’slawalongthemagneticfieldarederivedfromthebasicequationsofthegyrokineticVlasov,Poisson,andAmperesystemandareusedtodescribethespatio-temporalevolutionofthefieldquantitiesoftheelectrostaticpotentialφandthelongitudinalcomponentofthevectorpotentialAz.Thebasicalgorithmisequivalenttosolvingthereduced-MHD-typeequationswithkineticcorrections,inwhichMHDphysicsrelatedtoAlfvenmodesarewelldescribed.Theestimationofperturbedelectronpressurefromparticledynamicsisdominant,whiletheeffectsofothermomentsarenegligible.Anotheradvantageofthealgorithmisthatthelongitudinalinducedelectricfield,Etz=-■z/■t,isexplicitlyestimatedbythegeneralizedOhm’slawandusedintheequationsofmotion.Furthermore,theparticlevelocitiesalongthemagneticfieldareused（vz-formulation）insteadofgeneralizedmomentums（pz-formulation）,hencethereisnoproblemof’cancellation’,whichwouldotherwiseappearwhenAzisestimatedfromtheAmpere’slawinthepz-formulation.ThesuccessfulsimulationofthecollisionlessinternalkinkmodebythenewGpic-MHDwithrealisticvaluesofthelarge-scaleandhigh-betatokamaksrevealedtheusefulnessofthenewalgorithm.

简介：MHD问题是一个经典的概率推理难题。该研究以67名大学生为被试,探讨了不同问题情境即中奖情境与生存情境对MHD问题解决的影响。结果表明：在生存情境下,被试MHD问题的推理成绩显著优于中奖情境。

简介：

简介：在这份报纸，我们与不可压缩的条件为3DMHD方程的答案考虑整齐标准。由使用一些古典不平等，我们分别地以速度地和磁场的一个部件在某些足够的条件下面获得三维的MHD方程的强壮的答案的整齐。

简介：NonlinearMHDKelvin-Helmholtz（K-H）instabilityinapipeistreatedwiththederiva-tiveexpansionmethodinthepresentpaperThelinearstabilityproblemwasdiscussedinthepastbyChandrasekhar（1961）andXuetal.（1981）.Nagano（1979）discussedthenonlinearMHDK-Hinstabilitywithinfinitedepth.Heusedthesingularperturbationmethodandextrapolatedtheob-tainedsecondordermodifierofamplitudevs.frequencytoseekthenonlineareffectontheinstabilitygrowthrateγ.However,inourview,suchanextrapolationisinappropriate.Becausewhentheinstabili-tysetsin,thegrowthratesofhigher,ordertermsontherighthandsideofequationswillexceedthecor-respondingsecularproducingterms,sotheexpansionwillstillbecomemeaninglessevenifthesecularproducingtermsareeliminated.Mathematicallyspeaking,it’simpossibletoderiveformula（39）whenγ02isnegativeinNagano’spaper.Moreover,evenasearlyasγ02→O+,theexpansionbe-comesinvalidbecausethe2ndordermodifierγ2（inhisformula（56））tendstoinfinity.Thisweak-nessisremovedinthispaper,andtheresultisextendedtothecaseofapipewithfinitedepth.

简介：Inthisarticle,wemainlystudythelocalequationofenergyforweaksolutionsof3DMHDequations.WedefineadissipationtermD(u,B)thatstemsfromaneventuallackofsmoothnessinthesolution,andthenobtainalocalequationofenergyforweaksolutionsof3DMHDequations.Finally,weconsiderthe2Dcaseattheendofthisarticle.

简介：

简介：

简介：Electroncyclotronresonanceheating(ECRH)isaveryreliableelectronheatingmethodinmagnetizedplasmas.Thepowerdepositionprofileislocalizedandpredictable.HighpowerECRHwasusedintheRTPtokamaktoachievestableplasmas

简介：WeprovetheexistenceofaweaksolutionforageneralizedquantumMHDequationina2-dimensionalperiodicboxforlargeinitialdata.Theexistenceofaglobalweaksolutionisestablishedthroughathree-levelapproximation,energyestimates,andweakconvergencefortheadiabaticexponentγ>1.

简介：本文根据I型彗尾的背景材料,分析了MHD波的色散关系,探讨了螺旋波的稳定性及其演变的特征。根据初始条件的不同,有的彗尾中可以产生稳定的螺旋波,有的则不然,只能是浑云状态。文章给出了理论推演,列出了观测结果,理论和观测能较好地符合。可进一步结合Hale-Bopp彗星的观测,进行对比和检验。

简介：Magnetohydrodynamic(MHD)acceleratorisproposedasanextgenerationpropulsionsystem.Itcanbeusedtoincreasetheperformanceofapropulsionsystem.TheobjectiveofthisstudyistoinvestigatetheperformanceofMHDacceleratorusingnon-equilibriumairplasmaasworkinggas.Inthisstudy,thefundamentalperformanceofMHDacceleratorsuchasflowperformanceandelectricalperformanceisevaluatedatdifferentlevelsofappliedmagneticfieldusing1-Dnumericalsimulation.ThenumericalsimulationisdevelopedbasedonasetofdifferentialequationswithMHDapproximation.TosolvethissetofdifferentialequationstheMacCormackschemeisused.AspecifiedchanneldesignedanddevelopedatNASAMarshallSpaceFlightCentreisusedinthenumericalsimulation.Thecompositionofthesimulatedairplasmaconsistsofsevenspecies,namely,N2,N,O2,O,NO,NO+,ande-.Theperformanceofthenon-equilibriumMHDacceleratorisalsocomparedwiththeequilibriumMHDaccelerator.

简介：Non-lineardevelopmentofdoubletearingmodesinducedbyelectronviscosityisnumericallysimulated.MHDflowlayersaredemonstratedtomergeinthedevelopmentofthemodes.Theshearedflowsareshowntoliejustattheboundariesofthemagneticislands,andtohavesuffcientlevelsrequiredforinternaltransportbarrier(ITB)formation.PossiblecorrelationbetweenthelayerformationandtriggeringofexperimentallyobservedITBs,preferentiallyformedinproximitiesofrationalfluxsurfacesoflowsafetyfactors,isdiscussed.

简介：稳定的laminar流动的问题的一个近似答案一粘滞在一张拉长的表上的不可压缩的电子上进行的液体被介绍。途径基于拉长流动问题的变量然后使用最少的广场方法最小化一个微分方程的剩余的想法。流动特征上的磁场的效果与Hartman数字的不同价值通过数字计算被表明。

简介：

简介：

简介：有电磁的领域的不同安排的一个MHD生成器将带在三个模式工作的生成器。quasi-one-dimensional近似被用于MHD发电机的模型分析操作模式的内部机制。为有一个一致经常的磁场的MHD发电机，特定的批评电场E<潜水艇class=“a-plus-plus”>cr被要求速度超声的入口流动进亚声的出口流动。否则，发电机比E与一个更大的电场在一个稳定的模式工作稳定的超声的流动在出口在被提供的cr，或发电机比E与一个更小的电场在一个窒息的模式工作超声的入口流动在隧道在被窒息的cr。在不同操作模式的详细流动地特征被讨论，表明有电磁的地的操作模式的关系。

简介：摘要MHD患者自我护理的内容主要包括饮食护理、用药护理、运动指导、血管通路护理。MHD患者需要摄入高热量、优质的高蛋白质、高钙低磷、低盐低钾、低脂肪，注意水分的摄入和补充适量的水溶性维生素。MHD患者常常伴有并发症，需要相关的药物进行治疗。运动指导要求按照科学性、针对性、循序渐进和个体化的原则来执行。鼓励患者患者参加运动锻炼。内瘘是生命线，要积极维护。留置导管时，要保持导管部位清洁，干燥。

简介：Anewmethodforconstructingthesymmetricformforthehyperbolicsystemsisintroduced.ThenanewsymmetricformoftheequationsofMHDtransverseflowisconstructedbyaddinganadditionalequation.Withthisnewform,weobtainthelocalexistenceofsmoothsolutionincludingthecasethattheinitialdensitymaytendtothevacuumstateatinfinity.Furthermore,theuniformlyaprioriestimationfortheclassicalsolutionsisestablishedandtheglobalsmoothsolutionsforakindofinitialdataareobtained.

简介：