简介:Spreadoffiresmokeintheelevatorshaftofahigh-risebuildingisinfluencedbymanydrivingfacts.Wesimulatesmokespreadingintheelevatorshaft,stairroom,andpre-chamberwithandwithoutdifferentsuppliedpressurizedair.Thesimulationshowsthatsmokemovesveryfastintheelevatorshaft.Whena12floorhigh-risebuildingisinfire,smokecanfilluptheelevatorshaftinlessthan1.5minafterafirestarted,temperatureintheelevatorshaftcanbehigherthan187?Cin5min,andtheconcentrationofCOcanalsoreachahighlevel.Theelevatorshafthasaverylowvisibilityinlessthanabout100s.
简介:Objective:Toinvestigatethesignificanceofextra-nodalspreadinspecialhistologicalsub-typesofbreastcancerandtherelationshipofsuchspreadwithprognosticparameters.Methods:Atotalof303breastcancercaseswereclassifiedaccordingtotumortype,andeachtumorgroupwassubdividedaccordingtoage,tumordiameter,lymphnodemetastasis,extra-nodalspread,veininvasionintheadjacentsofttissue,distantmetastasis,andimmunohistochemicalcharacteristics[estrogenreceptor(ER),progesteronereceptor(PR)existence,p53,c-erbB-2,andproliferativerate(Ki-67)].The122caseswithextra-nodalspreadwereclinicallyfollowedup.Results:Anextra-nodalspreadwasobservedin40%(122cases)ofthe303breastcancercases.Thespreadmostfrequentlypresentedinmicropapillarycarcinomahistologicalsub-type(40cases,75%),butleastfrequentlypresentsinmucinouscarcinoma(2cases,8%).Patientswithextra-nodalspreadhadahighaveragenumberofmetastaticlymphnodes(8.3)andahighdistantmetastasisrate(38cases,31%)comparedwithpatientswithoutextra-nodalspread.Conclusion:Theexistenceofextra-nodalspreadintheexaminedbreastcancersub-typeshaspredictivevalueinforecastingthenumberofmetastaticlymphnodesandthediseaseprognosis.
简介:<正>Myengagementinthelong-termefforttostopthespreadofdesertsinChinastartedfromaverydistinctpersonalexperience.WhenIarrivedinBeijingin1998toserveasambassadortoChina,Iwasgreetedbytheyellowduststorms.ThegalesthatbroughtinthesandanddustwereverypowerfulanditwasnosmallshocktoseeBeijing’s
简介:《集韵》是宋代继《广韵》之后的又一部大型官修韵书。根据卷首《韵例》,它在收字、注音、释义各个方面都尽量要求完备,这和陆法言《切韵》以来的韵书“论南北是非,古今通塞”,“捃选精切,削除疏缓”的旨趣有所不同。正因为如此,有人认为它是一个“大杂烩”,用途不大。其实这部书收字三万以上,大大超过了《广韵》;收录字的读音也比《广韵》多,有的字的读音多达十个以上;字义的解释也比较丰富,收录的义项不少。这部书除了音韵学上的价值外,在文字学和训诂学方面也有重要的作用。只要运用得当,它对研究古音,探索词义,考察字形结构都有很大的好处。除此以外,《集韵》注音将切语的类隔切改为音和切,每个韵内部的小韵按照声母的发音部位和发音方法类聚在一起,开宋代韵书革命的先河,也是值得注意的。
简介:前人怀疑《兰亭集序》者,或以为从文章到书法都是伪造的,或以为此伪作乃出自陈僧智永之手。鉴于东晋南朝历史文化条件,本文则以为这些看法值得商榷。自来皆肯定传世今本《集序》书法水平极高,“章法为古今第一”,是“神品”,而据唐人书品论,智永书法虽善,乃指其隶书(正书)、草书,其行书水平则稍差,与王羲之相距甚远,这就意味智永绝对无法伪造出这一“神品”来。而且鉴于当时琅琊王氏礼教家风,智永的“末裔”身份也决定他不大可能违反孝道,去伪造远祖文章、墨迹;史载《集序》墨迹的存在在唐代以前几乎是不为人知晓的,因而纵使撇开智永,假定当时另有一造假足以乱真的无名顶级书法高手,在南朝社会风气影响下,为了获取经济或政治利益而伪造王羲之墨迹,则此伪造目的必然决定他选择目标乃是易于出手,为人们熟知、欣羡的王氏墨迹名作,而不会去找一当时毫无名气、很可能无人问津的《集序》去伪造;这些表明,唐代以前没有伪造《集序》的条件,不存在伪造《集序》这一问题,由唐代流传至今的今本《集序》当是真品。