学科分类
/ 1
9 个结果
  • 简介:继qq.com.cn域名被同行提前拥有后,腾讯QQ再次在CN二级域名开放的20分钟内,被别人抢注了qq.cn域名。3月17日,中国国家顶级域名。CN下的二级域名全球开放注册。CN开通注册不到20分钟的时间内,qq.cn被确认为厦门注册商务向务

  • 标签: 中国 互联网 网络名称 地址资源 资源管理
  • 简介:TheEnglishconstruction'XandY'referstothecoordinationoftwowordswithandasconjunction,XandYbeingofthesamepartofspeechandparallelmeanings.ThispaperisacognitivestudyofthelinearorderoftheEnglishconstruction'XandY'fromtheperspectivesofcognitivesalience,cognitiveiconicity,andcognitionofformalrules.Thelinearcharacteristicsof'XandY'arerevealedasfollows:1)salience-downgradingorder;2)chronologicaliconicity;3)cognitionofalphabeticorderandprosodicorder.

  • 标签: 线性特性 认知研究 结构 英语 时间顺序
  • 简介:SH-250Y自动点胶机是将精密点胶和准确定位安装在一个紧凑的桌面系统中,实现二者完美地整合于一体的全自动点胶机一、主要特点L.X、Y、Z三轴可作平面及立体运行;2.可作点、线、圆、圆弧和椭圆等图形涂胶

  • 标签: 点胶机 全自动 桌面系统 定位安装 涂胶
  • 简介:Accordingtothedipoletransitionselectionrulesandbychoosingpropertransitionchannels,itisfoundthattheinvertedY-typefour-levelschemecanbeclassifiedintoninedifferent2nd-ordersubschemeswhenusingcorrespondinglaserfields,andtheycanbefurtherclassifiedintoeighty3rd-ordersubschemesindetailaccordingtodifferentexcitingintensitiesthatareappliedindifferentchannels.Inthispaper,thestructuremultiformityofinvertedY-typefour-levelschemeisdiscussedandthedemonstrationsonsomesubschemesarealsogiven.Atthesametime,thesubschemeswhichhavebeenstudiedarepointedout,butmostofthemhavenotbeenresearchedtothebestofourknowledge.

  • 标签: 四能级 多样性 光学相干 Y型 结构 系统
  • 简介:Y&D7200N桌上型自动点/涂胶机,外形紧凑,坚固耐用,可与胶阀、针筒搭配使用,适用于任何点胶应用的自动化,极其适用于成本考量和紧凑空间要求时应用。采用行业领先的软件通过示教盒按步骤指导用户操作的指示,数分钟内可完成复杂的点胶操作程序编写。

  • 标签: 涂胶机 桌上型 动点 用户操作 搭配使用 程序编写
  • 简介:Thispaperpresentsanewarraystructureforestimatingtwo-dimensional(2-D)direction-of-arrivals(DOAs).ThestructureiscalledY-shapedarray,whichhas10%betteraccuracypotentialthanthenewly-developedL-shapedarray.Agreatmeritisitsabilitytoestimate2-DDOAswhicheverdirectionsthearrivingsignalscomefrom,comparedwithL-shapedarraywhoseperformancedependsonDOAs.Simulationresultsaregiventodemonstratetheperformanceofthenewarray.

  • 标签: DOA estimation ARRAY SIGNAL processing ARRAY
  • 简介:Silicon-on-insulator1×2Y-junctionOpticalSwitchBasedonWaveguide-vanishingEfect①②ZHAOCezhou(Microelectron.Institute,XidianUnive...

  • 标签: Integrated Optics OPTICAL Switchs Y JUNCTION
  • 简介:Thesilicon-on-insulator(SOI)1×2Y-junctionopticalwaveguideswitchhasbeenproposedandfabricated,whichisbasedonthelargecross-sectionsingle-moderibwaveguidecondition,thewaveguide-vanishingeffectandthefree-carrierplasmadispersioneffect.Intheswitch,theSOItechniqueutilizersiliconandsilicondioxidethermalbondingandback-polishing.Theinsertionlossandextinctionratioofthedevicearemeasuredtobelessthan4.78dBand20.8dBrespectivelyatawavelengthof1.3μmandaninjectioncurrentof45mA.Responsetimeisabout160ns.

  • 标签: 全光学 光切换 Y型连接 波导 硅上绝缘