学科分类
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51 个结果
  • 简介:2006年8月,“ICPE2006国际物理教育大会”在日本东京召开,东南大学恽瑛教授在会议上作题为《通过双语物理教学培养大学一年级学生的创新能力》的报告,恽瑛教授带领的2005级本科生李鑫、杜源、胡特、姜坤也分别作了口头报告和张贴报告。他们在会议上的精彩发言与会议期间的表现,引起了与会代表和著名的《Science》杂志的极大兴趣。

  • 标签: 《SCIENCE》 大学一年级 日本东京 物理教育 创新能力 物理教学
  • 简介:送检地下水水型为HCO3^--SO4^2--Ca^2+-(Mg^2+)型,酸碱度为中性、水介质属氧化型(Eh=640my)、低矿化,样品水中各项水质分析项目为,K^++Na^+,Ca^2+,Mg^2+,Fe^3+,Cl^-,SO4^2-,HCO3^-,CO3^2-,NO3^-,OH^-;所对应分析值为0.670×10^-3,1.200×10^-3,0.400×10^-3,1.79×10^-3,0.036×10^-3,0.88×10^-3,2.074×10^-3,10^-5.863,0.035×10^-3,10^-7.07。

  • 标签: 地下水 Eh值 HCO3^- 应用 计算 析出
  • 简介:为了明确团聚现象及表面性质对ZnS纳米材料发光性质的影响,采用SiO2对ZnS材料进行了表面修饰,并对ZnS及ZnS/SiO2复合材料的光学性质进行对比研究。采用吸收光谱分析了包覆前后光吸收性质的差异,发现SiO2包覆后ZnS纳米材料的带边由333nm红移至360nm。为了研究ZnS纳米材料与ZnS/SiO2纳米复合材料的光发射性质,分别对含纳米材料的水溶液样品及粉末样品的发光光谱进行了采集。对比研究的结果表明,SiO2包覆后ZnS纳米材料在蓝紫光区的发光得到了明显增强。以氙灯作为激发光源所获得荧光光谱显示ZnS/SiO2粉末样品发光的积分强度增大为原来的17.5倍,但相同条件下针对溶液样品的测试结果显示其发光强度只增大了1.1倍,这种增强可用SiO2的存在抑制了ZnS纳米粒子间的团聚来解释,且这一推断由325nm紫外激光激发下获得的光致发光数据进行了验证。

  • 标签: 复合材料 ZnS/SiO2 发光 荧光增强
  • 简介:Variousagriculturalcropresiduesincludingcornstover,corncob,andsorghumstalkwithamoisturecontentof75wt%weresubjectedtoalongpretreatment(12-60h)withsupercriticalCO2(scCO2),atlowtemperature(50-80℃)andapressureof17.5-25.0Mpa.Thesugaryieldsfromtheenzymatichydrolysis(EH)ofthepretreatedsampleswereasmuchasthree-tofourfoldgreaterthanthoseaffordedbytherawmaterials.However,whenpretreatmentwasconductedwithinashorttime(e.g.0.5h),aspreviouslyreportedintheliterature,onlyaslightincreaseintheEHsugaryieldswasobserved.TheproposedscCO2pretreatmentmechanismdemonstratedtheroleofmoistureinthesystem.Wetting,softening,andswellingwereobservedtomainlyaffectthelignocellulosewhenasuitableamountofwaterwasadded.Finally,thesampleswereanalysedbyX-raydiffractionandscanningelectronmicroscopy,beforeandafterpretreatment,toinvestigatethechangesinthemicroscopicstructureofthebiomass.

  • 标签: LIGNOCELLULOSE scCO2 PRETREATMENT ENZYMATIC HYDROLYSIS SUGAR
  • 简介:为验证CO_2探测仪光学设计的合理性和可行性,采用单通道模拟样机,利用太阳光加漫反射板模式对大气光谱进行实验测试,并在实验室对单通道模拟样机进行光谱定标。利用光谱配准算法对两种方法得出的谱线位置进行匹配计算,结果表明:在吸收线深度稳定位置的配准峰值点偏差小于0.006nm,满足算法的精度要求。此种方法不仅验证了匹配算法的有效性,也验证了光学系统设计的合理性和可行性,为以后的光谱仪设计提供了理论与实验数据。

  • 标签: 探测仪 单通过光学系统 漫反射板 光谱配准
  • 简介:Anovelgas-phaseelectrocatalyticcellcontainingalow-temperatureprotonexchangemembrane(PEM)wasdevelopedtoelectrochemicallyconvertCO2intoorganiccompounds.TwodifferentCu-basedcathodecatalysts(CuandCu-C)werepreparedbyphysicalvapordepositionmethod(sputtering)andsubsequentlyemployedforthegas-phaseelectroreductionofCO2atdifferenttemperatures(70-90℃).ThepreparedelectrodesCuandCu-CwerecharacterizedbyX-raydiffraction(XRD),X-rayphotoemissionspectroscopy(XPS)andscanningelectronmicroscopy(SEM).Asrevealed,CuispartiallyoxidizedonthesurfaceofthesamplesandtheCuandCu-Ccathodiccatalystswerecomprisedofaporous,continuous,andhomogeneousfilmwithnanocrystallineCuwithagrainsizeof16and8nm,respectively.Theinfluenceoftheappliedcurrentandtemperatureontheelectro-catalyticactivityandselectivityofthesematerialswasinvestigated.Amongthetwoinvestigatedelectrodes,thepureCucatalystfilmshowedthehighestCO2specificelectrocatalyticreductionratesandhigherselectivitytomethanolformationcomparedtotheCu-Celectrode,whichwasattributedtothehigherparticlesizeoftheformerandlowerCuO/Curatio.Theobtainedresultsshowpotentialinterestforthepossibleuseofelectrical「enewableenergyforthetransformationofCO2intovaluableproductsusinglowmetalloadingCubasedelectrodes(0.5mgCucm2)preparedbysputtering.

  • 标签: C02 VALORIZATION ELECTRO-REDUCTION CU catalyst PEM
  • 简介:Inthiswork,MoOxpromotedIr/SiO2catalystswerepreparedandusedfortheselectivehydrogenolysisoftetrahydrofurfurylalcohol(THFA)to1,5-pentanediolinacontinuousflowreactor.Theeffectsofdifferentnoblemetals(Ir,Pt,Pd,Ru,Rh),supportsandIrcontentswerescreened.Amongtheinvestigatedcatalysts,4wt%Ir-MoOx/SiO2withaMo/Iratomicratioof0.13exhibitedthebestcatalyticperformance.ThesynergybetweenIrparticlesandthepartiallyreducedisolatedMoOxspeciesattachedonthemisessentialfortheexcellentcatalyticperformanceofIr-MoOx/SiO2.ThecatalystexhibitedabetterhydrogenolysisefficiencyofTHFAwiththeselectivityof1,5-pentanediolof65%–74%ataconversionofTHFAof70%–75%whentheinitialTHFAconcentrationisrangingfrom20wt%and40wt%.AndhighersystempressurewasalsoinfavoroftheconversionofTHFA.Duringastabilitytest,theconversionofTHFAand1,5-pentanediolyieldoverIr-MoOx/SiO2decreasedwithreactiontime,whichcanbeexplainedbytheleachingofMospeciesduringthereaction.

  • 标签: 戊二醇 催化剂 SiO 化学选择性 氢解 四氢糠基
  • 简介:Catalyticpropertiesofthemetal-organicframeworkCr-MIL-101insolvent-freecycloadditionofCO2toepoxidestoproducecycliccarbonatesusingtetrabutylammoniumbromideasco-catalysthavebeenexploredundermildreactionconditions(8barCO2,25C).Styreneandpropylenecarbonateswereformedwithhighyields(95%and82%,respectively).CatalyticperformanceofCr-MIL-101wascomparedwithotherMOFs:Fe-MIL-101,Zn-MOF-5andHKUST-1.Thecatalyticpropertiesofdifferentquaternaryammoniumbromides,Cr-MIL-101aswellasPW12/Cr-MIL-101compositematerialhavebeenassessedinoxidativecarboxylationofstyreneinthepresenceofbothtert-butylhydroperoxideandH2O2asoxidantsat8100barCO2and2580Cwithselectivitytostyrenecarbonateupto44%at57%substrateconversion.

  • 标签: 环状碳酸酯 环氧化物 金属有机 季铵盐 催化合成 框架
  • 简介:酒吧的气质永远是暧昧的粉红,情人节浪漫的约会场所。《风尚player》发扬粉红精神,为情人节的各位们,寻找最具电眼的醒目酒保,再通过秘密的大考验来挑选出TOP10有型又有料的酒保。我们的目的只有一个,就是各位大饱眼福的同时,知道哪里有最有型并有料的醒目酒保啦!毕竟养眼又能调美酒的酒吧,谁不愿意去呢?

  • 标签: TOP10 酒吧 PLAYER 情人节
  • 简介:Throughournewly-developed'chemicalvapordepositionintegratedprocess(CVD-IP)'usingcarbondioxide(CO2)astherawmaterialandonlycarbonsourceintroduced,CO2couldbecatalyticallyactivatedandconvertedtoanewsolid-formproduct,i.e.,carbonnanotubes(CO2-derived)ataquitehighyield(thesingle-passcarbonyieldinthesolid-formcarbon-productproducedfromCO2catalyticcaptureandconversionwasmorethan30%atasingle-passcarbon-base).Forcomparison,whenonlypurecarbondioxidewasintroducedusingtheconventionalCVDmethodwithoutintegratedprocess,nosolid-formcarbon-materialproductcouldbeformed.IntheadditionofsaturatedsteamatroomtemperatureinthefeedforCVD,thereweremuchmoreend-openingcarbonnano-tubesproduced,ataslightlyhighercarbonyield.Theseinspiringworksopenedaremarkableandalternativenewapproachforcarbondioxidecatalyticcapturetosolid-formproduct,comparingwiththatofCO2sequestration(CCS)orCO2mineralization(solidification),etc.Asaresult,therewasmuchlessbodyvolumeandalmostnogreenhouseeffectforthissolid-formcarbon-materialthanthoseofprimitivecarbondioxide.

  • 标签: 二氧化碳 集成工艺 CVD 碳材料 体形 催化
  • 简介:Thescientificprogramofthegroupcoversbigbangnucleosynthesis,hydrostaticburninginstarsandexplosivenucleosynthesisinsupernova.Byconsideringnon-equilibriumstatistics,wesuggestapossiblewaytosolvetheLiprobleminbigbangnucleosynthesis.The13C(α,n)16Oisthemajorneutronsourceforthes-processhappeninginAGBstars.The19F(p,α)16Oisrelevanttotheproductionoffluorine.WearedevelopingexperimentalplatformstostudytheimportantreactionforthefirsttimedirectlyattheirstellarenergiesinJinpingUndergroundLaboratory.The59Festellardecayrateisimportantfortheproductionof60Fe,animportantisotopewhosegammarayhasbeenobservedbysatellites.WedetermineitsstellardecayrateforthefirsttimeusingexperimentalB(GT)strength.Thenewratereducesthediscrepancyofthe60Feyieldsbetweenthemodelpredictionsandtheobservations.Theundergroundexperimentisexpectedtobeginin2018.

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  • 简介:“夜生活”的概念并不纯粹,对某些人来说,它就是一种白天的生活。有那么一群人.当我们于梦乡中酣畅淋漓时.还在默默地忙碌着,我们笑称他们为夜猫子,其实他们只是和我们作息时间表不同罢了。“日落而作.日出而息”.是他们基本的作息时间.“黑白颠倒”是他们的基本特征.他们自我标榜:我们是夜行一族。在万籁俱寂的夜晚,人的思绪却很容易被集中起来。而夜行一族乃至很多可以自主时间的人宁愿将工作时间定在晚上,据说这样可以取得比白天更高的工作效率。可是当看到他们的工作状态时.我们不禁会暗地佩服他们的勇气和能力,就是在那气压骤降、血压骤升的时段里,他们也一样找到了人生很HIGH的境界。以下十个职业便是夜行族堪称最具快感最过瘾又不乏时尚魅力的职业.我们一起看看他们都在忙些什么……

  • 标签: 白皮书 作息时间表 专家 工作时间 工作效率 工作状态
  • 简介:TheobjectiveoftheApollon10PWprojectisthegenerationof10PWpeakpowerpulsesof15fsat1shotmin-1.InthispaperabriefupdateonthecurrentstatusoftheApollonprojectispresented,followedbyamoredetailedpresentationofourexperimentalandtheoreticalinvestigationsofthetemporalcharacteristicsofthelaser.Morespecificallythedesignconsiderationsaswellasthetechnologicalandphysicallimitationstoachievetheintendedpulsedurationandcontrastarediscussed.

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