简介:自我介绍和X1一样基于前驱平台打造的SUV,车体略小,却更具有轿跑气质奔驰的入门级SUV产品,基于MFA前驱平台打造,早已由北京奔驰负责国产尺码长4379毫米,宽1824毫米,高1560毫米,轴距为2670毫米长4449毫米,宽1804毫米,高1535毫米,轴距为2699毫米动力引入国内的车型入门款采用前轮驱动,搭载1.5T直列3缸涡轮增压汽油机,最大功率为140马力,峰值扭矩为220牛·米,匹配7挡双离合变速箱;2.0T发动机最大功率为192马力,峰值扭矩为280牛·米,前驱车型上和7挡双离合变速箱匹配,四驱车型上和8挡自动变速箱匹配
简介:Ag-MgF2cermetfilmswithdifferentAgfractionswerepreparedbyvacuumevaporation.Themicrostruc-tureofthefilmswasexaminedbyRamanscatteringtechnique.Thesurface-enhancedRamanspectrumforMgF2moleculesinthecermetfilmstronglysuggeststheexistenceofAgnanoparticlesdispersedinMgF2matrix.TheintensitiesoftheRamanspectraofAg-MgF2cermetfilmsincreasewithAgfraction.TheenhancementofRamanscatteringdisappearswhenAgcontentreacheswt.20%.TheanalyseswiththetransmissionelectronmicroscopyshowedthatAg-MgF2cermetfilmsaremainlycomposedofamor-phousMgF2matrixwithembeddedfaced-center-cubicAgnanoparticles.Itsuggeststhatthepercolationthresholdshouldbearoundwt.20%ofAgcontent.
简介:进行了G20CrNi2MoA钢代替G20Cr2Ni4A钢制造轴承滚子的热处理试验。试验表明,用G20CrNi2MoA钢代替G20Cr2Ni4A钢制造轴承滚子,渗碳过程易于控制,淬火时可根据滚子尺寸不同,选择合适的淬火冷却介质,能完全保证G20CrNi2MoA钢制造的轴承滚子的淬火质量,在满足技术要求的同时,即节约了材料费用,又减少了热处理加工费用,具有推广价值。
简介:继成功开发“红岩新大康——金刚”系列重卡后,近日,又一凝聚红岩人智慧的红岩6×2双转向前桥重卡在红岩公司完成试制,该车具有承载能力强、经济效益好、安全性高等特性。红岩6×2双转向前桥汽车成功问世,进一步丰富红岩系列产品型谱,将为红岩公司扩大市场占有、提高核心竞争力带来新的机遇。
简介:Nitridatedβ-Ga_2O_3(100)substratewasinvestigatedasthesubstrateforGaNepitaxialgrowth.Theeffectsofnitridationtemperatureandsurfaceroughnessofβ-Ga_2O_3wafersontheformationofGaNwerestudied.Itwasfoundthatthemostoptimizednitridationtemperaturewas900°C,andhexagonalGaNwithpreferredorientationwasproducedonthewell-polishedwafer.Thenitridationmechanismwasalsodiscussed.
简介:由于Newman有理算子对|x|逼近效果较好,所以考虑利用Newman-α型有理算子对|x|~α进行逼近.构造Newman-α型有理算子,讨论Newman-α算子在Chebyshev结点组下逼近|x|~α的收敛速度,最后得到精确的逼近阶为O(1/(n~αlogn)).该结果包含了α=1时的情形.
简介:AprototypeRamanlidarwasdesignedformonitoringtroposphericCO_2profileandotherscientificin-vestigations.ThethirdharmonicofNd:YAGlaser(354.7-nmwavelength)wasusedasstimulatedlightsourcetoprovidenighttimemeasurements.FilterwithhighrejectionratioperformancewasusedtoextractCO_2RamansignalsfromRayleigh-Miescatteringsignalseffectively.Toimprovetherealtimemonitoringfunction,atwo-channelsignalcollectionsystemwasdesignedtocollectCO_2andN_2Ramanscatteringsig-nalssimultaneously.TheN_2Ramanscatteringsignalswereusedtoretrieveaerosolextinctioncoefficient.TypicalfeaturesofCO_2concentrationprofileandaerosolextinctioncoefficientinHefeiwerepresented.ThemixingratioofatmosphericCO_2inHefeicanreachabout360-400ppmv.