简介:本文用临界点理论中的能量最小原理得到了一类具(q(t),P(t))-Laplacian项的二阶非自治系统存在周期解的充分条件.
简介:研究p-致凸Banach空间中渐近半压缩映象的修正的Mann迭代过程和修正的Ishikawa迭代过程的强收敛性.本文始终假设X是P-致凸Banach空间.最近,r-渐近半压缩映象的概念被引入,并给出了X中该映象(此时,r=P)的修正的Mann迭代过程和修正的Ishikawa迭代过程的强收敛性定理,文章所得结果改进、推广和统一了近期相关结果.
简介:ThinheavilyMg-dopedInGaNandGaNcompoundcontactlayerisusedtoformNi/AuOhmiccontacttop-GaN.ThegrowthconditionsofthecompoundcontactlayeranditseffectontheperformanceofNi/AuOhmiccontacttop-GaNareinvestigated.Itisconfirmedthatthespecificcontactresistivitycanbelowerednearlytwoordersbyoptimizingthegrowthconditionsofcompoundcontactlayer.WhentheflowrateratiobetweenMgandGagassourcesofp++-InGaNlayeris10.6%andthethicknessofp++-InGaNlayeris3nm,thelowestspecificcontactresistivityof3.98×10-5?·cm2isachieved.Inaddition,theexperimentalresultsindicatethatthespecificcontactresistivitycanbefurtherloweredto1.07×10-7?·cm2byoptimizingthealloyingannealingtemperatureto520℃.
简介:通过构建数据科技乌托邦,对火星移民计划的可持续性问题进行探讨。首先,对比火星与地球的异同点,根据移民的生存目标分析火星乌托邦的社会构成,并制定火星移民的选拔标准;其次,对火星乌托邦的人口分布情况运用Leslie人口模型进行动态演化,并基于人口的演化结果分析收入、教育、平等问题;采用生产法确定火星的经济生产总值,并建立双对数线性模型求解四大产业不同学历劳动者的工资增长函数;通过对火星教师数量与教育产出水平指标的评估,借鉴柯布-道格拉斯生产函数分析教育的投入与产出情况,综合考察火星教育的发展状况;再从人格尊严、经济产出、学历教育角度,引用基尼系数全面地评价火星乌托邦的平等问题,以验证火星移民计划的可行性与可持续性。
简介:Wepresenta940nmquasi-continuouswavesemiconductorlaserdesignedasabuildingblockforhigh-powerfibercoupledpumpmodules.Thelasercomprisesa400μmnarrow-stripearraymountedonanaluminumnitridesubstrateusinghardsolder.Thechiphasbeenoptimizedforhighopticalpowerandlowlateralfar-fieldangles.Twoverticalandsixlateralstructurevariationshavebeeninvestigatedtodeterminethebestachievableperformance.Operatingat1mspulsewidthandarepetitionrateof10Hz,thelaserdevicereachesamaximumpulsepowerof86Wfroma400μmapertureandmorethan62%maximumconversionefficiency.Lowlateralfar-fieldangles(95%powerenclosed)of11.5and13.5,dependingontheepitaxialdesign,enableefficientmultimodefibercoupling.Thepotentialforhighlyreliableapplicationshasbeendemonstrated.