简介：五亿年前的声音是怎么样的？德国FISCHER＆FISCHER成立于1981年，三十多年来专注于板岩音箱的设计与制作，创始人ThomasFischer的祖父拥有一个开采板岩的石场，大概在40年前他们开始采用板岩来制作音箱，令这种深藏了5亿年的岩石被重新赋予生命。

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简介：乔治费歇尔（GeorgFischer）在昆山的新铸铁厂正式成立。因该厂将生产与安全性相关的关键部件，所以生产设施全部高标准打造

简介：AsustainablestrategyforFischer–Tropschironcatalystsissuccessfullyachievedbyembeddingofsynergisticpromotersfromarenewableresource,corncob.Theiron-basedcatalysts,namedas“corncob-driven”catalysts,arecomposedofironspeciessupportedoncarbonasprimaryactivecomponentsandvariousminerals（K,Mg,Ca,andSi,etc.）aspromoters.Thecorncob-drivencatalystsarefacilelysynthesizedbyaone-pothydrothermaltreatmentundermildconditions.Thecharacterizationresultsindicatethattheformationofironcarbidesfromhumboldtineisclearlyenhancedandthemorphologyofcatalystparticlestendstobemoreregularmicrospheresafteraddingcorncob.Itisobservedthattheoptimizedcorncob-drivencatalystexhibitsahigherconversionthanwithoutpromoters’catalystinFischer–Tropschsynthesis（ca.73%vs.ca.49%）.Moreimportantly,asynergisticeffectexistsinmultiplepromotersfromcorncobthatcanenhanceheavyhydrocarbonsselectivityandlowerCO2selectivity,obviouslydifferentfromthecatalystwithpromotersfromchemicals.Theproposedsynthesisrouteofcorncob-drivencatalystsprovidesnewstrategiesfortheutilizationofrenewableresourcesandeliminationofenvironmentalpollutantsfromchemicalpromoters.

简介：深圳中心·天元项目建筑设计师在超高层的外墙设计了大量的天然石材干挂,希望以天然石材呈现出建筑的完美与奢华.而要实现这-设计理念,则必须充分考虑天然石材在时间维度上的耐久性、在空间维度上的安装维护便利性,以及在人性关怀维度上的万无-失和安全可靠性.

简介：E、Fischer(以下简称E、F)对葡萄糖分子构型的测定是有机化学的教学难点之一,今以南大本为依循线索(见南京大学有机化学教研组编《有机化学》下册P278—P279),兹对E、F法做一简析。为了避免误解,需要说明的是,这不是一篇有关某个实验的史料介绍的文字,文中一些无关宏旨的叙述纯然是为了叙述的自然性的需要而做出的。葡萄糖分子构型的确定,包括两方面的工作:第一:开链式中各手型碳原子构型的确定。第二:氧环式中半缩醛环大小的确定。由于氧环式中半缩醛环的大小的推证较为简单,故从略。本文仅限于对开链式中各

简介：Carbonnanotube(CNT)-supportedRunanoparticleswithmeansizesrangingfrom2.3to9.2nmwerepreparedbydifferentpost-treatmentsandstudiedforFischer-Tropsch(FT)synthesis.TheeffectsofRuparticlesizeoncatalyticbehaviorswereinvestigatedatbothshorterandlongercontacttimes.Atshortercontacttime,wherethesecondaryreactionswereinsignificant,theturnoverfrequency(TOF)forCOconversionwasdependentonthemeansizeofRuparticles;TOFincreasedwiththemeansizeofRuparticlesfrom2.3to6.3nmandthendecreasedslightly.Atthesametime,theselectivitiestoC5+hydrocarbonsincreasedgraduallywiththemeansizeofRuparticlesupto6.3nmandthenkeptalmostunchangedwithafurtherincreaseinRuparticlesize.Atlongercontacttime,C10-C20selectivityincreasedsignificantlyattheexpenseofC21+selectivity,suggestingtheoccurrenceoftheselectivehydrocrackingofC21+toC10-C20hydrocarbons.

简介：摘要目的对Fischer编制的简版就医态度量表(attitudes toward medical help-seeking scale，ATMHSS)进行汉化，并分析就医态度量表中文版在中国居民群体中的信度和效度。方法以方便取样的方法，选取来自不同城市居民769名，进行问卷调查，通过项目分析及探索性因素分析初步筛选，确定量表最终项目。检验ATMHSS的中文修订版的信度和效度。结果通过探索性因子分析，共提取四个主因子，分别为行为意向(10个条目)、非宿命论(10个条目)、医疗信任(6个条目)和非回避态度(4个条目)。ATMHSS各维度与总分相关系数在0.641～0.839之间，各维度相关系数在0.213～0.556之间。ATMHSS与各效标变量均呈显著正相关(r＝0.406～0.696，均P<0.01)。验证性因素分析结果显示，各项目拟合度良好(χ2＝752.572，df＝391，χ2/df＝1.925，RMSEA＝0.045，SRMR＝0.058，CFI＝0.902，GFI＝0.903，IFI＝0.903，TLI＝0.891)。ATMHSS的内部一致性信度在0.726～0.879之间，重测信度在0.622～0.736之间。结论ATMHSS中文修订版信效度良好，可作为测量就医态度的有力工具。

简介：Thl-responseplaysacrucialroleindeterminingpathogenesisoforgan-specificautoimmunediseases.ItisbelievedthatbothIL-12andINF-αareinitiatorstoregulateTh1-response.Inourexperimentalautoimmuneuveitis(EAU)model,bothLewisandFischer344ratssharethesameMHCclassⅡImolecules,whileLewisratisEAUsusceptibleandFischer344ratisEAUresistant.However,underthesameconditionofimmunization,ifpertussistoxin(PTX)wasinjectedintraperitoneallyasanadditionaladjuvant,Fischer344ratcandevelopEAU.InthisstudyweinvestigatewhichmechanismsareinvolvedintheinductionofEAUinCFA+R16+PTX-treated(CRP-treated)Fischer344rats.InvivoandinvitrodatademonstratedthatThl-cytokine,IFN-γmRNAexpressionwassignificantlyincreasedindiseasetargettissue-eyesandindraininglymphnodecellsofCRP-treatedFischer344rat.WhenIL-12andIFN-αmRNAexpressionwerecomparedintheexperimentalgroups,onlyIFN-αmRNAexpressionwasassociatedwithEAUdevelopment.TodistinguishthesourcesofIFN-αproducingcells,itwasobservedthatIFN-αexpressionwasmainlyproducedbymacrophages.ItwasfurtherconfirmedthatnormalmacrophagefromFischer344ratwasabletoproducesignificantIFN-αinthepresenceofPTX.ThedatastronglysuggestedthatIFN-αmightbeinvolvedininitiatingThl-celldifferentiationandinturncontributetotheinductionofEAU.HighIFN-αexpressioninducedbyPTXmayrepresentanovelpathwaytoinitiateThlresponseinFischer344rat.

简介：ThedetailedkineticsofFischer-TropschsynthesisoveranindustrialFe/Cu/La/Sicatalystwasstudiedinacontinuousspinningbasketreactorundertheconditionsrelevanttoindustrialoperations.ReactionrateequationswerederivedonthebasisofLangmuir-HinshelwoodHougen-WatsontypemodelsforFischer-Tropschsynthesisbasedonpossiblereactionssetsoriginatedfromthecarbide,enolicandcombinedenol/carbidemechanisms.Kineticmodelcandidateswereevaluatedbytheglobaloptimizationofkineticparameters,whichwererealizedbyfirstminimizationofmulti-responseobjectivefunctionswithconventionalLevenberg-Marquardtmethod.Itwasfoundthatanenolicmechanismbasedmodelcouldproduceagoodfitoftheexperimentaldata.Theactivationenergyforparaffinformationis95kJmol-1whichissmallerthanthatforolefinformation(121kJmol-1).

简介：【名师箴言】在复习函数时应做到：第一：立足课本、抓好基础；第二：强化数形结合意识、分类讨论思想、建模思想，不论是对于正、反比例函数，还是一次函数、二次函数而言，待定系数法都是重要的思想方法；第三：针对中考重点与热点，总结解题规律，强化基本技能，精心选材，避免引入难度过高、计算量过大、技巧性过强的题

简介：K-promotediron/carbonnanotubescomposite(i.e.,FeK-OX)waspreparedbyaredoxreactionbetweencarbonnanotubesandK_2FeO_4followedbythermaltreatmentsonapurposeastheFischer–Tropschcatalystforthedirectconversionofsyngastolowerolefins.ItscatalyticbehaviorswerecomparedwiththoseoftheothertwoFe-IMandFeK-IMcatalystspreparedbyimpregnationmethodfollowedbythermaltreatments.ThenovelFeK-OXcompositecatalystisfoundtoexhibithigherhydrocarbonselectivity,lowerolefinsselectivityandchaingrowthprobabilityaswellasbetterstability.ThecatalyststructureperformancerelationshiphasbeenestablishedusingmultipletechniquesincludingXRD,Raman,TEMandEDSelementalmapping.Inaddition,effectsofadditionalpotassiumintotheFeK-OXcompositecatalystontheFTOperformancewerealsoinvestigatedanddiscussed.Additionalpotassiumpromotersfurtherendowthecatalystswithhigheryieldoflowerolefins.Theseresultsdemonstratedthattheintroductionmethodofpromotersandironspeciesplaysacrucialroleinthedesignandfabricationofhighlyactive,selectiveandstableiron-basedcompositecatalystsfortheFTOreaction.

简介：Aseriesof3wt%Ruembeddedonorderedmesoporouscarbon(OMC)catalystswithdifferentporesizeswerepreparedbyautoreductionbetweenrutheniumprecursorsandcarbonsourcesat1123K.RunanoparticleswereembeddedonthecarbonwallsofOMC.CharacterizationtechnologiesincludingpowerX-raydiffraction(XRD),nitrogenadsorption-desorption,transmissionelectronmicroscopy(TEM),andhydrogentemperature-programmedreduction(H2-TPR)wereusedtoscrutinizethecatalysts.ThecatalystactivityforFischer-Tropschsynthesis(FTS)wasmeasuredinafixedbedreactor.Itwasrevealedthat3wt%Ru-OMCcatalystsexhibitedhighlyorderedmesoporousstructureandlargesurfacearea.Comparedwiththecatalystswithsmallerpores,thecatalystswithlargerporeswereinclinedtoformlargerRuparticles.These3wt%Ru-OMCcatalystswithdifferentporesizesweremorestablethan3wt%Ru/ACcatalystduringtheFTSreactionsbecauseRuparticleswereembeddedonthecarbonwalls,suppressingparticlesaggregation,movementandoxidation.ThecatalyticactivityandC5+selectivitywerefoundtoincreasewiththeincreasingporesize,however,CH4selectivityshowedtheoppositetrend.ThesechangesmaybeexplainedintermsofthespecialenvironmentoftheactiveRusitesandthediffusionofproductsintheporesofthecatalysts,suggestingthattheactivityandhydrocarbonselectivityaremoredependentontheporesizeofOMCthanontheRuparticlesize.

简介：求函数的定义域一般有三种类型；第一种是给出具体的函数解析式求定义域；第二种是不给出具体的函数解析式，而由f（x）的定义域，求复合函数f[g（x）]的定义域，此时采用整体考虑的方法；第三种是应用问题中求函数的定义域，此时除了考虑函数解析式有意义外，还应该考虑问题的实际意义对自变量的制约．

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简介：<正>考点解读函数及其表示法点击考点一映射的概念映射是一种特殊的对应,映射中的集合A,B可以是数集,也可以是点集或其他集合,这两个集合有先后顺序,从A到B的映射与从B到A的映射是截然不同的.

简介：<正>纵观近几年的高考数学试题,对函数的考查几乎每年都有,函数与集合、数列、不等式、解析几何等知识的综合题,因其涵盖的知识点多,易于数学建模,且有考查较强的思维能力的功能.在今后的高考命题中综合性题型仍会成为热点和重点,并可能逐渐加强.

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简介：在数学分析中,一般都用下列解析式来定义双曲正弦、双曲余弦、双曲正切和双曲余切的。这些函数为什么叫双曲函数,它们与双曲线有什么关系。为了弄清这些问题,下面用双曲线来定义双曲函数。一、双曲函数的定义

简介：[摘要]以函数思想来贯穿中学数学内容更有利于提高数学教学质量，在培养学生的创新精神和应用数学知识解决问题的过程中，函数思想具有其他思想方法所不及的指导作用。因此，数学教学应大力加强对函数思想的进一步研究，并努力将函数思想渗透到一切可能的教学内容中去。[关键词]初中数学教学数学思想函数思想知识结构教学质量九年义务教育阶段的数学课程，致力于使学生获得适应未来社会生活和进一步发展所必需的重要数学事实以及基本的数学思想方法和必要的应用技能。把数学思想作为基础知识进行传授是加强素质教育的一项创举。我们认为，以函数思想来贯穿中学数学内容更有利于提高数学教学质量。在培养学生的创新精神和应用数学知识解决问题的过程中，函数思想具有其他思想方法所不及的指导作用。因此，在教学中把函数思想渗透到一切可能的教学内容中去......