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32 个结果
  • 简介:Extractingrare-earthelementsfromcoalcouldsoonbeeconomicalinU.S.ExtractedfromthereportofUNIVERSITYPARK,Pa.TheU.S.couldsoondecreaseitsdependenceonimportingvaluablerare-earthelements,accordingtoateamofPennStateandU.S.DepartmentofEnergyresearcherswhofoundacost-effectiveandenvironmentallyfriendlywaytoextractthesemetalsfromcoalbyproducts.UsingbyproductsofcoalproductionfromtheNorthernAppalachianregionoftheU.S.,theteaminvestigatedwhetherachemicalprocesscalledionexchangecouldextractREEsinasafermannerthanotherextractionmethods.Resultsshowthationexchangeismoreenvironmentallyfriendlyandrequiresless

  • 标签: 技术 稀土元素 环境友好 成本效益 研究人员 大学园区
  • 简介:Terahertzwaves,sittinginthegapbetweenthemiddleinfraredandmillimeterwaveregions,areknownasthelasvacantareaoftheelectromagneticspectrumthathasnotquitebeenunderstoodandbroughtintoapplications.TheTerahertzregionhasbeenthefocusofresearchworldwidesinceearly1990s.DuetotheiruniquecharacteristicsTerahertztechnologieshaveawiderangeofapplications,suchashazarddetection,highspeeddatacommunications

  • 标签: 太赫兹波 应用 论文摘要 科技期刊 技术 电子
  • 简介:Terahertzwaves,sittinginthegapbetweenthemiddleinfraredandmillimeterwaveregions,areknownasthelastvacantareaoftheelectromagneticspectrumthathasnotquitebeenunderstoodandbroughtintoapplications.TheTerahertzregionhasbeenthefocusofresearchworldwidesinceearly1990s.Duetotheiruniquecharacteristics,

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  • 简介:Brainisthemostcomplexorganofhumanbeings.Thecompleteunderstandingofhumanbrains’functionsisanongoingchallengeforneuroscience.Althoughtherearemanytechniquesusedforbrainresearch,neuroscientists,physicists,andengineersarestillexploringotheraccessofresearchforapplications.Terahertz(THz)spectroscopyandimagingmaycreatesuchaspaceforbrainresearch.THzspectroscopictechnique,whichisanovelmedicalimagingmodality,attractsattentionofbiomedicalapplicationsduetoitsuniquefeaturesincludingnon-invasive,non-ionizing,andhighsensitivitytobiomoleculesandtissues.Inthisarticle,weintroduceourrecentinvestigationsonneuroscienceusingTHztechniques,meanwhile,introduceother’sworkinthisfield.Ourandothers’investigationsindicatethattheTHzspectroscopyandimagingtechniquecanbeusefulfordiagnosingbraintumorsandneurodegenerativediseases.THzspectroscopyandimaginghasthepotentialtobecomereal-timeinvivodiagnosticmethods.

  • 标签: 生物医学应用 成像技术 神经科学 太赫兹 神经退行性疾病 光谱技术
  • 简介:Thispaperoptimizestheburiedchannelcharge-coupleddevice(BCCD)structurefabricatedbycomplementarymetaloxidesemiconductor(CMOS)technology.TheoptimizedBCCDhasadvantagesoflownoise,highintegrationandhighimagequality.Thechargetransferprocessshowsthatinterfacetraps,weakfringingfieldsandpotentialwellbetweenadjacentgatesallcausethedecreaseofchargetransferefficiency(CTE).CTEandwellcapacityaresimulatedwithdifferentoperatingvoltagesandgapsizes.CTEcanachieve99.999%andthewellcapacityreachesupto25000electronsforthegapsizeof130nmandthemaximumoperatingvoltageof3V.

  • 标签: CMOS工艺 优化设计 BCCD 互补金属氧化物半导体 电荷耦合装置 热膨胀系数
  • 简介:随着IT技术的发展,计算机设备未来的设计方向也日新月异,尤其是触摸技术及相关产品随着智能化应用的升级,其市场日趋火热。下面让我们一起体验触摸技术所带来的喜悦吧!

  • 标签: 英语学习 学习方法 阅读知识 阅读材料
  • 简介:Weproposeadepolarizerbasedontheprincipleofacollectionofhalf-waveplateswithrandomlydistributedopticaxes.Thedesignisdemonstratedbymeansofdynamicallyphotopatterningliquidcrystalintorandomlyalignedhomogeneousdomains.Wecharacterizetheliquidcrystaldepolarizerfor1550nmandC-band(1520–1610nm).Adegreeofpolarizationoflessthan5%isobtainedforanylinearlypolarizedlight.Thisstudyprovidesapracticalcandidateforhigh-performancedepolarizers.

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  • 简介:JEST—JournalofElectronicScienceandTechnology,formerly,JournalofElectronicScienceandTechnologyofChina,ispublishedquarterlydevotingtothestate-of-the-artachievementsinelectronicscienceandtechnology,includingthemosthighlightareas:communicationtechnology,electronicsystemsandarrayprocessing,computerscienceandinformationtechnology,optoelectronicand

  • 标签: 电子科技 作者信息 科技期刊 科学与技术 计算机科学 生物电子学
  • 简介:Inthelastdecadestheinterestinthebiomassgasificationprocesshasincreasedduetothegrowingattentiontotheuseofsustainableenergy.Biomassisarenewableenergysourceandrepresentsavalidalternativetofossilfuels.Gasificationisthethermochemicalconversionofanorganicmaterialintoavaluablegaseousproduct,calledsyngas,andasolidproduct,calledchar.Thebiomassgasificationrepresentsanefficientprocessfortheproductionofpowerandheatandtheproductionofhydrogenandsecond-generationbiofuels.Thispaperdealswiththestateoftheartbiomassgasificationtechnologies,evaluatingadvantagesanddisadvantages,thepotentialuseofthesyngasandtheapplicationofthebiomassgasification.Syngascleaningthoughfundamentaltoevaluateanygasificationtechnologyisnotincludedinthispapersince;intheauthors'opinion,adedicatedreviewisnecessary.

  • 标签: 生物质气化技术 可持续能源 热化学转化 艺术 气体产品 可再生能源
  • 简介:Nuclearfusionhasenormouspotentialtogreatlyaffectglobalenergyproduction.Thenext-generationtokamakITER,whichisaimedatdemonstratingthefeasibilityofenergyproductionfromfusiononacommercialscale,isunderconstruction.Wallerosion,materialtransport,andfuelretentionareknownfactorsthatshortenthelifetimeofITERduringtokamakoperationandgiverisetosafetyissues.Thesefactors,whichmustbeunderstoodandsolvedearlyintheprocessoffusionreactordesignanddevelopment,areamongthemostimportantconcernsforthecommunityofplasma-wallinteractionresearchers.Todate,lasertechniquesareamongthemostpromisingmethodsthatcansolvetheseopenITERissues,andlaser-inducedbreakdownspectroscopy(LIBS)isanidealcandidateforonlinemonitoringofthewallsofcurrentandnext-generation(suchasITER)fusiondevices.LIBSisawidelyusedtechniqueforvariousapplications.Ithasbeenconsideredrecentlyasapromisingtoolforanalyzingplasma-facingcomponentsinfusiondevicesinsitu.ThisarticlereviewstheexperimentsthathavebeenperformedbymanyresearchgroupstoassessthefeasibilityofLIBSforthispurpose.

  • 标签: LIBS NUCLEAR fusion plasma-facing COMPONENTS
  • 简介:Withthedeepeningofthewesterndevelopment,supportsofthecountryforthewesternregionofChinacontinuedtoincrease.Italsoincludesthesupportforenterpriseinnovationactivities,byreducingthetax,exemption,subsidiesandothermeans.Duetotheeffectofgovernmentsubsidiesonenterpriseinnovationactivitiesisdifferentindifferentregions,industriesandsoon,thereisabigcontroversy.Therefore,weusethepaneldataoflistedcompaniesinmanufacturingindustryofwesternregionassamplesforempiricalresearch,toresearchtheeffectofgovernmentsubsidiesonenterpriseinnovationactivitiesinthewesternofChina,thestudyfoundthatoverall,thecurrentgovernmentsubsidieshasapositiveeffectonEnterpriseR&Dinvestment,whereasthelastyear’sgovernmentsubsidyhasanegativeeffectonR&Dinvestment,butit’sincentiveeffectisgreaterthanthecrowdingouteffect.Thestudyalsofoundtherearedifferenteffectsbetweenthestate-ownedenterprisesandprivateenterprises,thecrowdingouteffectofprivateenterprisesisverysmallandnotsignificant.

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  • 简介:Wepresentintegrated-opticbuildingblocksandfunctionalphotonicdevicesbasedonamorphoussiliconon-insulatortechnology.Efficientdeep-etchedfiber-to-chipgratingcouplers,low-losssingle-modephotonicwirewaveguides,andcompactpowersplittersarepresented.Basedonthesub-μmphotonicwires,2×2Mach–Zehnderinterferometersandadd/dropmicroringresonators(MRRs)withlowdevicefootprintsandhighfinesseupto200wererealizedandstudied.Compactpolarizationrotatorsandsplitterswith≥10dBpolarizationextinctionratiowerefabricatedforthepolarizationmanagementon-chip.Thetuningandtrimmingcapabilitiesofthematerialplatformaredemonstratedwithefficientmicroheatersandapermanentdevicetrimmingmethod,whichenabledtherealizationofenergy-efficientphotoniccircuits.Wavelengthmultiplexersintheformofcascadedfilterbanksand4×4routersbasedonMRRswitchesarepresented.Fabricationimperfectionswereanalyzedandpermanentlycorrectedbyanaccuratelaser-trimmingmethod,thusenablingeight-channelmultiplexerswithrecordlowmetricsofsub-mWstaticpowerconsumptionand≤1°Ctemperatureoverhead.Thehighqualityofthefunctionaldevices,thehightuningefficiency,andtheexcellenttrimmingcapabilitiesdemonstratethepotentialtorealizelow-cost,denselyintegrated,andultralow-power3D-stackedphotoniccircuitsontopofCMOSmicroelectronics.

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  • 简介:Inthispaper,weproposeamethodtoimproveanti-radiationcapabilitybycoatingheavymetalX-rayprotectionglasswithcompoundphotoniccrystallayers,basedontheuniquepropertyofphotoniccrystalthatlightcannotbepropagatedwithintherangeofbandgaps.Usingtheplanewaveexpansionmethod,wemadeatheoreticalstudyofparametersaffectingthebandgapstructuresofone-dimensionalphotoniccrystals.Basedonthefindings,wechoseappropriatematerialsandcompoundstructureofphotoniccrystalsoastogethighX-rayreflectioncoatingphotoniccrystallayers.Bythismethod,thereflectionratewithinX-raywavelengthcanreachthemaximumvalueof100%,andtheaveragevalueofover90%.Evenlow-costheavymetalX-rayprotectionglassofabsorptioncoefficientvaluecanachievethedesiredeffect.Thus,thismethodgreatlydecreasestheanti-radiationrequirementsofheavyX-rayprotectionglass.

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