简介:Inthispaper,MPt/C(M=La,Nd)catalystsofPEMFCweresynthesizedbymicrowaveradiationprocess.ThecrystallinityandstructureofcatalystswererespectivelyanalyzedbyXRDandnitrogenadsorptiontests.Theactivityofcatalystswasinvestigatedbyelectrochemistryexperiment.Theresultsshowedthat:1)comparedwithPt/Ccatalystpreparedbytypicalimpregnation-reductionprocess,thesizeofMPt/CcatalystparticledecreasedandtheavailablecrystalforO2reductionincreased;2)theMPt/CcatalystshadrelativelyhighBETsurfaceareas;and3)thesecrystaltransformationsoftheMPt/Ccatalystbroughthightheelectrocatalyticactivity,andasaresult,improvedthepowerofPEMFC.
简介:At12:07UT(8:07pmChinaStandardTime)on2017Oct4,abrightbolidewaswidelyobservedintheShangri-LaregionoftheProvinceofYunnan,China(Figure1).TheeventwaswellobservedbythegeneralpublicasittookplaceonthenightoftheMidAutumnFestival,whichisassociatedwithmoongazing.SonicboomsandgroundshakingwerereportedinanareaofaboutathousandsquarekilometersnorthwestofShangri-LaCity.DatafromU.S.governmentsensorssuggeststhattheimpactenergyoftheeventwasapproximately0.54ktTNTequivalent,withtheterminusofthebolidepositionedat28.1°N,99.4°E.ThisisthelargestobservedbolideeventoverlandsincethebolideeventthattookplaceinMauritaniaon2016Jun27(1.2kt).
简介:小森公司跨入A1市场的机型LA37,是一部拥有Lithrone系列高性能表现的单张纸胶印机,具有性价比高、机身结构紧凑、不占空间等优势。13000sph的适宜印刷速度、0.04~0.6mm的适印纸张厚度以及640×940mm的最大纸张尺寸,能够广泛满足印刷业务的不同需求,尤其可在中、短版印刷中发挥最佳印刷效率。LA37,全面满足了多种印刷需求。
简介:摘要目的探讨脑白质疏松(LA)与认知功能障碍的临床关系,并分析LA所致认知功能障碍域的特点。方法选取80例LA患者,根据不同分级对其分组,对比不同组间认知功能障碍发生率。采用蒙特利尔认知功能量表(MoCA)对所有患者的认知功能进行量化评定,对比不同组间评分差异,分析LA所致认知功能障碍域的特点。结果LA-IV级组认知功能障碍发生率远高于LA-I级组、LA-II级组和LA-III级组(P<0.05),而MoCA评分远低于其他三组(P<0.05);LA-III级组认知功能障碍发生率也远高于LA-I级组、LA-II级组(P<0.05),而MoCA评分远低于其他两组(P<0.05);LA-II级组认知功能障碍发生率远高于LA-I级组(P<0.05),而MoCA评分则远低于后者(P<0.05);LA所致认知功能障碍患者视空间与执行能力、注意与集中力、延迟回忆能力、抽象思维能力和定向能力均与LA分级有明显关联(P<0.05)。结论LA严重程度与认知障碍的发生情况存在明显关联,且与视空间与执行能力、注意与集中力、延迟回忆能力、抽象思维能力和定向能力的损害都有明显关联。