简介:Intrinsiccarrierconcentration(ni)isoneofthemostimportantphysicalparametersforunderstandingthephysicsofstrainedSiandSi1-xGexmaterialsaswellasforevaluatingtheelectricalpropertiesofSi-basedstraineddevices.Uptonow,thereportonquantitativeresultsofintrinsiccarrierconcentrationinstrainedSiandSi1-xGexmaterialshasbeenstilllacking.Inthispaper,byanalyzingthebandstructureofstrainedSiandSi1-xGexmaterials,boththeeffectivedensitiesofthestatenearthetopofvalencebandandthebottomofconductionband(NcandNv)at218,330and393KandtheintrinsiccarrierconcentrationrelatedtoGefraction(x)at300KweresystematicallystudiedwithintheframeworkofKPtheoryandsemiconductorphysics.ItisfoundthattheintrinsiccarrierconcentrationinstrainedSi(001)andSi1-xGex(001)and(101)materialsat300KincreasessignificantlywithincreasingGefraction(x),whichprovidesvaluablereferencestounderstandtheSibasedstraineddevicephysicsanddesign.
简介:Moleculardynamics(MD)simulationswereperformedtostretchtherectangulargraphenesheetsdopedwithsilicon,nitrogenorboronatoms.Young’smodulus,ultimatestress(strain)andenergyabsorptionweremeasuredforthegraphenesheetswiththedopingconcentration(DC)rangingfrom0to5%.Theemphasiswasplacedonthedistincteffectsofeachindividualdopantonthefundamentalmechanicalpropertiesofgraphene.TheresultsindicatedthatincorporatingthedopantsintographeneledtoanalmostlineardecreaseinYoung’smodulus.Monotonicreductionsinultimatestrength,ultimatestrainandenergyabsorptionwerealsoobserved.Suchdopingeffectswerefoundtobemostsignificantforsilicon,lesspronouncedforboron,andsmallornegligiblefornitrogen.Theoutputsprovideanimportantguidanceforthedevelopmentandoptimizationofnovelnanoscaledevices,andfacilitatethedevelopmentofgraphene-basedM/NEMS.
简介:SiC/Si<潜水艇class=“a-plus-plus”>3N<潜水艇class=“a-plus-plus”>4合成是用自我繁殖的高温度的燃烧合成-Si3N<潜水艇class=“a-plus-plus”>4粉末和适当数量原文如此搽粉。两个都,sintering添加剂,系统被使用,它是YAN(Y2O3艾尔2O3AlN)并且YN(Y2O3AlN)。影响在SiC/Si的sintering行为上原文如此满意<潜水艇class=“a-plus-plus”>3N<潜水艇class=“a-plus-plus”>4合成被调查。结果证明有二个sintering添加剂系统的样品的密度,收缩,弯曲力量,坚硬,和破裂坚韧随内容的增加增加第一原文如此然后甚至当原文如此内容不断地增加时,减少。样品的重量损失的趋势是相反的。有最好的机械性质的样品原文如此满意在二个系统是不同的。为YAN系统,当原文如此内容到达10时,样品的最好的机械性质被获得?%,当至于YN系统它是5时?%。YN样品的性质比YAN样品优异。J阶段(2Y2O3吠敨爠畯整漠?灡汰楹杮氠睯瀠敲獳牵?景???慐漠?桴?獡搭獩牰灯牯楴湯瑡摥朠敲湥挠浯慰瑣搠牵湩?桴?敤潳灲楴湯爠'啼礃A慮楴湯瀠潲散獳椠?楳畴栠瑯搠晥牯慭楴湯椠??灳牡?汰獡慭猠湩整楲杮?偓?猠獹整?慣?扯慴湩挠浯汰瑥汥?敲潣扭湩摥丠??洠条敮?楷桴朠潯?湡獩瑯潲祰愠摮洠条敮楴?牰灯牥楴獥?桔?慭楸畭?慭湧瑥捩瀠潲数瑲敩??????汣獡?愢瀭畬?汰獵?慭?猯'T?????鮪徬鞪??极脿???醰鑛??鴿鎘銳????�
简介:Thisstudyaimstoinvestigatetheeffectofthe1-stepquenchingandpartitioning(Q&P)processonthemicrostructureandtheresultingVicker’shardnessof0.3C-1.5Si-1.5Mnsteelbyusingin-situdilatometry,opticalmicroscopy(OM),scanningelectronmicroscopy(SEM),X-raydiffractometry(XRD),andVicker’shardnessmeasurement.Systematicanalysesindicatethatthemicrostructureofthespecimensquenchedandpartitionedat150℃,200℃,250℃,and300℃mainlycompriseslathmartensiteandretainedaustenite.Thedilatometrycurveofthespecimenpartitionedat150℃ispresumablyascribedtotheformationofisothermalmartensite.Intheearlystagesofpartitioningat200℃,thenearlyunchangeddilatationcurveiscloselyrelatedtothesynergisticeffectofisothermalmartensiteformationandtransitionalepsiloncarbideprecipitation.Inthelaterstagesofpartitioningat200℃,theslightincreaseinthedilatationcurveisduetothecontinuousisothermalmartensiteformation.Withfurtherincreaseinpartitioningtemperatureto250℃,thedilatationincreasesgraduallyupto3600s,whichisrelatedtocarbonpartitioningandlowerbainiteformation.Partitioningatahighertemperatureof300℃causesarapidincreaseinthedilatationcurveduringtheinitialstages,whichsubsequentlylevelsoffuponprolongingthepartitioningtime.Thisismainlyattributedtotherapiddiffusionofcarbonfromathermalmartensitetoretainedausteniteandcontinuousformationoflowerbainite.
简介:通过EMS(Ethylmethylsulfonate,甲基磺酸乙酯)诱变豫谷1号获得一个遗传稳定的谷子小穗突变体si-sp1,该突变体突出表现为穗部变小,同时伴随有株高降低、单码小花数减少和根系变小等表现型变异。与野生型豫谷1号相比,突变体的穗长和株高分别降低了37.8%和9.0%,单穗粒重和单码小花数分别降低了40.3%和31.7%,但千粒重增加了20.2%。遗传分析表明,si-sp1突变性状由1对隐性基因控制。以si-sp1为母本、辽谷1号为父本构建的F2定位群体的隐性单株,将突变基因定位在8号染色体上CAAS8003与SSR1038间约11.02M的距离内,为下一步精细定位并分离该基因奠定了基础。
简介:在同一直线上的双脉搏的导致激光的故障光谱学被使用一双毫微秒Nd在Si水晶上执行:在1064nm射出的钇铝柘榴石激光来源。光谱紧张和选择Si原子、离子的线的signalto-噪音比率被用来评估光排放。当改变interpulse延期时间和二的精力比率时,光排放紧张被记录搏动的激光。线紧张和signal-to-noise比率上的数据获得延期时间的效果也被调查了。基于结果,最佳的interpulse延期时间,二的精力比率搏动了激光,和完成原子、离子的最大值的数据获得延期时间衬里紧张被作出对有利的裁决有在同一直线上的双脉搏的激光途径的Si血浆的产生。为观察的线紧张变化的主导的机制也被讨论。另外,在不同的门的血浆温度和电子数字密度推迟时间和不同interpulse延期时间被导出。血浆在更短的interpulse延期时间在电子温度和电子数字密度上防护的重要影响被观察。
简介:Theproblemofair-fuelratio(AFR)controloftheportinjectionsparkignition(SI)engineisstillofconsiderableimportancebecauseofstringentdemandsonemissioncontrol.Inthispaper,thestaticAFRcalculationmodelbasedonin-cylinderpressuredataandontheadaptiveAFRcontrolstrategyispresented.Themodelutilisestheintakemanifoldpressure,enginespeed,totalheatrelease,andtherapidburnangle,asinputvariablesfortheAFRcomputation.Thecombustionparameters,totalheatrelease,andrapidburnangle,arecalculatedfromin-cylinderpressuredata.ThisproposedAFRmodelcanbeappliedtothevirtuallambdasensorforthefeedbackcontrolsystem.Inpracticalapplications,simpleadaptivecontrol(SAC)isappliedinconjunctionwiththeAFRmodelforport-injectedfuelcontrol.TheexperimentalresultsshowthattheproposedmodelcanestimatetheAFR,andtheaccuracyoftheestimatedvalueisapplicabletothefeedbackcontrolsystem.Additionally,theadaptivecontrollerwiththeAFRmodelcanbeappliedtoregulatetheAFRoftheportinjectionSIengine.
简介:ThemicrostructuralchangesofFe83Si4B13amorphousmotheralloyduringtheheatingprocesswereinvestigatedbyLaserScanningConfocalMicroscopy(LSCM),andthephasetransformationwasdeterminedbytheThermo-Calccalculations.ThedifferencesinthemeltingpointsmeasuredbyDifferentialScanningCalorimetry(DSC)andLSCM,andthoseobtainedbyThermo-Calccalculationswerealsodiscussed.ItisfoundthatthemeltingpointsmeasuredbyDSCandLSCMarerelativelysimilar,whereastheonsetandendofthemeltingtemperaturescalculatedbyThermo-CalcsoftwarearehigherthanthosemeasuredbyDSCandobservedbyLSCM.
简介:研究了经不同温度热处理后的LaFe11.6Si1.4合金的相和组织结构,并探究其相变机理.铸态LaFe11.6Si1.4合金在高温热处理时经历包析反应和包晶反应.在低于1423K左右时,铸态LaFe11.6Si1.4合金发生Fe(Si)+LaFeSi→1∶13固固包析反应;在1423~1593K,发生Fe(Si)+LaFeSi→1∶13固液包晶反应;在1593~1739K,已形成的1∶13相熔化,合金处于固相Fe和液相两相区.基于相变热力学及动力学的因素,铸态合金在1523K附近具有最大的包晶反应驱动力,LaFe11.6Si1.4合金热处理5小时后,合金1∶13相含量最高.
简介:用滚镀的方法在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层,用扫描电子显微镜观察金刚石镀前和镀后的表面形貌,用DKY-1型单颗粒抗压强度测定仪测量金刚石单颗粒的抗压强度。用热压烧结的方法得到铁基结合剂金刚石节块,在INSTRON-5569型万能材料试验机上测量节块的抗弯强度,在NMW-1立式万能摩擦磨损试验机上测试节块的耐磨性。结果表明:在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层后,表面镀层均匀,纳米Si3N4/Ni复合镀层比纯Ni层更致密,更平滑,晶粒更细小;纳米Si3N4/Ni复合镀层金刚石单颗粒有更高的抗压强度;纳米Si3N4/Ni复合镀层金刚石铁基结合剂节块有更高的抗弯强度和更优良的耐磨性。