简介:Lightweightdesignisoneofthedevelopmenttrendsoftheautomobileindustry.AneffectivewaytoachievelightweightautobodiesistouseAHSS(advancedhighstrengthsteel)forthesafetycomponentsofautomobiles.ThisstudyhastakendoorsillreinforcementsmadeofmartensiteAHSSastheobject,andperformedresearchontheAHSSrollformingtechnologiesandprototypedevelopmentoftypicalasymmetricopencomponents.Bymeansoffiniteelementanalysis(FEA)andsimulation,studieshavebeencarriedoutonthespringbackandedgewavedefectsduringAHSSrollforming,andanoptimizedprocessdesignhasbeenachieved.Thegenerationmechanismsofverticalbows,horizontalcambers,twists,pre-punchedholedistortionandcutendflarehavebeenanalyzed,andsolutionstothesedefectshavebeengiven.Inaddition,tesingoftherollformingprocessforAHSShasbeenconductedandtypicalsampleswithrequireddimensionalaccuracyhavebeenmanufactured.Thisstudyhasprovidedtechnicalsupportforthelarge-scaleapplicationofAHSS.
简介:Large-scaleMIMO(multiple-inputmultiple-output)systemswithnumerouslow-powerantennascanprovidebetterperformanceintermsofspectrumefficiency,powersavingandlinkreliabilitythanconventionalMIMO.Forlarge-scaleMIMO,thereareseveraltechnicalissuesthatneedtobepracticallyaddressed(e.g.,pilotpatterndesignandlow-powertransmissiondesign)andtheoreticallyaddressed(e.g.,capacitybound,channelestimation,andpowerallocationstrategies).Inthispaper,weanalyzethesumrateupperboundoflarge-scaleMIMO,investigateitskeytechnologiesincludingchannelestimation,downlinkprecoding,anduplinkdetection.Wealsopresentsomeperspectivesconcerningnewchannelmodelingapproaches,advanceduserschedulingalgorithms,etc.
简介:随机的地震倒置是geostatistics和从地震记录,井木头,和geostatistics把信息集成到表面下的模型的以后的概率密度功能(PDF)的地震倒置技术的联合。Markov链蒙特卡罗(MCMC)方法被用来取样以后的PDF,表面下的模型特征能被分析推断一套以后的PDF样品。在这份报纸,我们首先介绍随机的地震倒置理论,讨论并且分析四个关键参数:地震数据signal-to-noise比率(S/N),variogram,以后的PDF样品数字,和井密度,并且建议这些参数的最佳选择。分析结果证明地震数据S/N调整在地震数据的影响之间的妥协,倒置上的geostatistics结果,variogram控制倒置结果的光滑,以后的PDF样品数字决定统计特征的可靠性源于样品,并且很好,密度影响倒置无常。最后,在随机的地震倒置之间的比较和确定的模型基于地震倒置显示随机的地震倒置能提供表面下的特性的更可靠的信息。
简介:Inordertoovercomethepoorlocalsearchabilityofgeneticalgorithm,resultinginthebasicgeneticalgorithmistime-consuming,andlowsearchabilityinthelateevolutionary,weusethegraycodinginsteadofbinarycodingatthebeginningofthecoding;weusemulti-pointcrossovertoreplacetheoriginalsingle-pointcrossoveroperation.Finally,theexperimentshowsthattheimprovedgeneticalgorithmnotonlyhasastrongsearchcapability,butalsothestabilityhasbeeneffectivelyimproved.
简介:DriftmarkedChina-Japantiesinmostpartofthe1990s,accompaniedwithwildswings.Thelastdecadeofthe20thcenturywitnessedthecommemorationofthe20thanniversary(1972-1992)ofdiplomaticnormalization,the50thanniversary(1945-1995)ofthevictoryoftheWarofResistanceAgainstJapaneseAggression,thefuroroverthe"NoWardecision"inJapan,andtheshockwavesfromthereorientationofJapan-U.S.relationshipin1996andtherevisionoftheguidelines
简介:AbstractMandibular condylar fractures are among the most common facial fractures and some of the most difficult to manage. Opinions about the management of mandibular condylar fractures differ among surgeons. With the implementation of new technology, an increased understanding of fracture management, and better functional and morphological outcomes reported in the literature, open reduction and internal fixation is becoming many surgeons’ preferred choice for the treatment of condylar fractures. Because surgical treatment of such fractures is complex, certain factors must be considered to achieve satisfactory outcomes. In this article, we summarise six key points in the management of mandibular condylar fractures: virtual evaluation of condylar fracture, a suitable surgical approach, good reduction, stable internal fixation, repair of the articular disc, and restoration of the mandibular arch width. We believe that these points will help to improve the prognosis of mandibular condyle fractures.
简介:Densechromiumsesquioxiderefractorieshavewidelybeenusedinthekilnsformakingalkai-freeandanti-alkaliglassfibersduetotheirexcellentre-sistancetomoltenglasses.Densificationsofchromiumsesquioxideduringsinteringcanbeblockedbyevaporationofchromiumtrioxidederivedfromoxidationathightemperature,Inthispaperthemech-anismofsinteringchromiumoxideandtheprocess-ingtechniqueformakingdensechromiumsesquiox-iderefractoriesarediscussed.Aprocessinlaboratoryscaleformakingdensechromiumsesquioxidebricksisdemonstrated.