学科分类
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174 个结果
  • 简介:EversincethenuclearbombingatHiroshimaandNagasakiin1945,nuclearweaponshavebecomeoneofthedefiningelementsinshapingtheworldstrategicsituationforbetterorworse.TheendoftheColdWarhasledtodramaticchangesintheworldsecuritylandscape.Theinternational

  • 标签: 加甜 入户
  • 简介:Developmentanduseofnuclearenergywasundoubtedlyoneothegreatestaccomplishmentsbymankindinscienceandtechnologyduringthe20thCentury.Oncediscovered,atomicenergy,likeothertechnologicaldiscoveries,hasbroughtaboutmixedresults:byitsmilitaryapplication,manproduceddeadlynucleararsenals;butatthesametimeitbecameamajorenergy

  • 标签: 核能 不扩散核武器 国际关系 和平 困境 出路
  • 简介:Theappearanceofnuclearweaponshasposedunprecedentedthreatsofwartomankind.Withjointeffortsoftheinternationalcommunity,aseriesofinternationalnormsandarrangementshavebeengraduallyestablished,mainlyinvolvingnucleardisarmamentandnucleararmscontrol,prohibitionoftheuseofnuclearweapons,aswellasnon-proliferationofnucleararms,effectivelyinfluencingnuclearactivitiesamongsovereignstates,wardingofftheoutbreakofnuclearwar,andlimitingthenumberofnuclearstates.Sincethebeginningofthe21stcentury,theinternationalstrategicenvironmenthasundergonemajorchanges.Mankindhasenteredanewagewhennuclearandmissiletechnologieshavebeenproliferatedinanacceleratedway,withIran'snuclearcapabilitysteadilygrowing,theDPRKobtainingnuclearweaponsbysuccessfullybreachingtheinternationalnuclearnon-proliferationregime,andnon-stateactorsbecomingthemajorsubjectstoproliferatenucleartechnologyandnuclearmaterials.Sincecomingintooffice,Trumphasthoroughlynegatedthepolicypropositionofanuclear-freeworldadvocatedbyObama,insistingonbuildingapowerfulmissiledefensesystem,developingnewformsofstrategicweapons,producinglow-yieldnuclearwarheads,andwithdrawingfromtheIraniannuclearagreement.Trump'spolicyadjustmenthasmuchweakenedthenucleartabooandthenuclearnon-proliferationregime,andhasinitiatedanewroundintheracetowardcuttingedgenuclearweaponstechnology,thusunderminingstrategicstabilityamongmajorpowers,allhighlightinghistoriclimitationsoftheinternationalnuclearorder.

  • 标签: INTERNATIONAL NUCLEAR order NUCLEAR weapons NUCLEAR
  • 简介:Thenonchromatinproteinousresidueofthecellnucleuswasrevealedinourlaboratoryasearlyasin1948andthenidentifiedbylightandelectronmicroscopyasresidualnucleoli,intranuclearnetworkandnuclearenvelopebefore1960,Thisstructuretermedafterwardsas'nuclearresidue','nuclearskeleton','nuclearcage','nuclearcarcass'etc.,wasmuchlater(in1974)isolated,studiedandentitledas'nuclearmatrix'byBerezneyandCoffey,towhomthediscoveryofthisresidualstructureisoftenwronlyascribed.Therealhistoryofnuclearmatrixmanifestationisreportedinthispaper.

  • 标签: 核碎片 细胞核 核基质 分部分离 历史
  • 简介:China’snuclearindustryisgoingtomakegreateruseofitsREmetalstogivefullplaytoitsenergy-producingtechnology.TheChinaNationalNuclearCorporation(CNNC)willconcentrateonthedevelop-mentofREpermanentmagnets,REfluore-scence,andREceramics.Theseproducts,alsohighprioritiesinthedevelopmentplanfortheREindustryinthecomingsixyears,areallhi-techandenergy-savingproducts.

  • 标签: NUCLEAR PERMANENT ceramics CONCENTRATE SAVING URANIUM
  • 简介:SinceAugust2005,IranononesideandtheUnitedStatesandtheEuropeancountriesontheotherhavebeenlockedinarangleovertheIrannuclearissueandtensionhassteadilyescalatedtoacriticalpointasbothsidessticktoanuncompromisingposition.InearlierJune2006,inordertobreakthedeadlock,theEU,withU.S.blessing,onceagainofferedIrananewpackageofincentivesinan

  • 标签: 阴山 五让 理川 小曲 对力 曲唱
  • 简介:在在10年的放射性的同位素横梁工厂的核物理学的研究活动被考察,未来方向也被讨论。在象试验性的设备一样设计设备的概念的想法被介绍。特殊强调被给在RIBF获得的加亮的结果。

  • 标签: 核物理学 工厂 横梁 研究活动 同位素 放射性
  • 简介:AsasignificantcomponentofChina’sefforttoresolveenergyproblems,nuclearpowerwillbekeptdevelopinginChina,andthesafetyofwhichcanbeensured.TheremarkscameatatimewhenuncertaintiesloomoverChina’snuclearfuture.Beijingsuspendedapprovalsfor

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  • 简介:Weisolatedandpurifiedmitochondriafrommouseliversandspinachleaves.WhenaddedintoeggextractsofXenopuslaevis,theycausednucleiofmouselivertoundergoapoptoticchanges.Chromatincondensation,marginationandDNAladderwereobserved.Afterincubatingisolatedmitochondriainsomehypotonicsolutions,andcentrifugingthesemixturesatmghspeed,wegotmitochondrialsupernatants.Itwasfoundthatintheabsenceofcytosolicfactor,thesupernatantalonewasabletoinduceapoptoticchangesinnuclei.Theeffectivecomponentswerepartlyofprotein.DNAfragmentationwaspartlyinhibitedbycaspaseinhibitorsAC-DEVD-CHOandAC-YVAD-CHO.Meanwhile,caspaseinhibitorsfullyblockedchromatincondensation.Primarycharacterizationofthenuclearendonuclease(s)inducedbymitochondrialsupernatantswasalsoconducted.ItwasfoundthatthisendonucleaseisdifferentfromendonucleaseG,cytochromec-inducednuclease,orCa^2+-activatedendonuclease.

  • 标签: 分离线粒体 诱导 核凋亡 核酸内切酶
  • 简介:Thenuclearmatrixattachmentregions(MARs)andthebindingnuclearmatrixproteinsinthe5'-flankingcisactingelementsofthehumanε-globingenehavebeenexamined.UsinginvitroDNA-matrixbindingassay,ithasbeenshownthatthepositivestage-specificregulatoryelement(ε-PREII,-446bp--419bp)upstreamofthisgenecouldspecificallyassociatewiththenuclearmatrixfromK562cells,indicatingthatε-PREIImaybeanerythroidspecificfacultativeMAR.IngelmobilityshiftassayandSouthwesternblottingassay,anerythroid-specificnuclearmatrixprotein(ε-NMPk)inK562cellshasbeenrevealedtobindtothispositiveregulatoryelement(ε-PREII).Furthermore,wedemonstratedthatthesilencer(-392bp--177bp)upstreamofthehumanε-globingenecouldassociatewiththenuclearmatricesfromK562,HELandRajicells.Inaddition,thenuclearmatrixproteinspreparedfromthesethreecelllinescouldalsobindtothissilencer,suggestingthatthissilencerelementmightbeaconstitutivenuclearmatrixattachmentregion(constitutiveMAR).Ourresultsdemonstratedthatthenuclearmatrixandnuclearmatrixproteinsmightplayanimportantroleintheregulationofthehumanε-globingeneexpression.

  • 标签: 核基质蛋白 K562细胞 结合区 人ε珠蛋白基因 基因表达 分子调节机制
  • 简介:Coactivatorsandcorepressorsregulatetranscriptionbycontrollinginteractionsbetweensequence-specifictranscriptionfactors,thebasaltranscriptionalmachineryandthechromatinenvironment,Thisreviewconsidertheaccessofnuclearandsteroidreceptorstochromatin,theiruseofcorepressorsandcoactivatorstomodifychromatinstructureandtheimplicationsfortranscriptionalcontrol.Theassemblyofspecificnucleoproteinarchitecturesandtargetedhistonemodificationemergeascentralcontrollingelementsforgeneexpression.

  • 标签: 类固醇激素受体 核受体 染色质结构重建 调节 转录