简介：信息产业部无线电管理局副局长谢飞波在“2006无线通信应用（国际）研讨会”上表示，在无线领域，中国在频率分配方面应有自己的立场，设备厂商应重视1．8GHz产品开发。谢飞波认为，目前我国1．8G频段的资源主要用于由信威公司开发的SCDMA，而目前还少有国外主流厂商的产品支持该频段。中国作为世界通信的主要市场，巨大的需求理应受到国内外设备厂商的充分重视。

简介：Cu2ZnSnS4(CZTS)粉末被使用ZnS和Cu2没有任何中介，原料直接在450愠?浥瑰?瑳浯d分阶段执行的SnS3

简介：Cu-andCo-substitutedNiZnferritethinfilms,Ni0.4-xZn0.6CuxFe2O4andNi0.5Zn0.5CoxFe2-xO4(0≤x≤0.2),aresynthesizedbysol-gelprocess.ThecrystallographicandmagneticpropertiesofCu-andCo-substitutedNiZnferritethinfilmshavebeeninvestigated.ThelatticeparameterdecreaseswithCusubstitutionandincreaseswithCosubstitution.ThesaturationmagnetizationdecreasesandthecoercivityincreaseswiththeincreaseofCusubstitution.Moreover,thesaturationmagnetizationgraduallyincreaseswiththeincreaseofCosubstitutionwhenx≤0.10,butdecreaseswhenx>0.10.Meanwhile,thecoercivityinitiallydecreaseswiththeincreaseofCosubstitutionwhenx≤0.10,butincreaseswhenx>0.10.

简介：采用挤压铸造方法制备了体积分数为55%、不同颗粒粒径增强的电子封装用SiCp/Cu复合材料,并分析了颗粒尺寸和热处理状态对材料物理性能和力学性能的影响规律.显微组织观察表明SiC颗粒分布均匀,复合材料组织致密;随着SiC颗粒尺寸的减小,复合材料的平均线膨胀系数和热导率均降低;退火处理可以降低复合材料的热膨胀系数,同时提高材料的热导率.复合材料具有高的弯曲强度和弹性模量,退火处理后材料的弯曲强度降低,但弹性模量变化不大.

简介：综合分析了Sn-Cu-Ni系无铅钎料的国内外研究现状,概述了Sn-Cu-Ni系无铅钎料的润湿性、微观组织、界面反应、力学性能、焊点可靠性、物理性能等性能特点。从钎焊工艺、添加微量元素等方面阐述了Sn-Cu-Ni系钎料各项性能的影响因素,并对Sn-Cu-Ni系钎料的应用前景和研究方向进行了展望。

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简介：UsingCu-phthalocyanine(CuPc),4,4'-diaminodiphenyletherandpyromelliticdianhydrideasmonomermaterials,polyimide(PI)thinfilmsdoped-CuPchavebeenpreparedontoglasssubstratebyvaporphaseco-depositionpolymerizationunderavacuumof2×10-3Paandthermalcuringofpolyamicacidfilminattemperatureof150-200Cfor60min.Inthisprocess,thepolymerizationcanbecarriedoutthroughcontrollingthestoichiometricratio,heatingtimeanddepositionratesofthethreemonomers.IRspectrumidentifiesthedesignedchemicalstructureofthepolymer.Theabsorptionofpolyimidedoped-CuPcisveryintenseinvis-rangeandnear-infraredbyUV-Visspectrum.And,thePIfilmsdoped-CuPcpolymerizedbyvaporphasedepositionhaveuniformity,finethermalstabilityandgoodnonlinearopticalproperties,andthethird-orderopticalnonlinearsusceptibilityx(2)withdegeneratefour-wavemixingcanbe1.984×10-9ESU.

简介：一个基站的信号覆盖是有一定范围的，为了能让无线电话在一个很大区域内(如一个市)都能打电话，就需要很多基站，使信号能覆盖这片区域。这样，当用户在移动过程中通话，就会发生切换。这种切换常规情况下会有1～2秒，有时有短暂停顿的感

简介：WefabricatepolycrystallineCu(In,Ga)Se2(CIGS)filmsolarcellsonpolyimide(PI)substrateattemperatureof450°Cwithsingle-stageprocess,andobtainapoorcrystallizationofCIGSfilmswithseveralsecondaryphasesinit.Forimprovingitfurther,thetwo-stageprocessisadoptedinsteadofthesingle-stageone.AnextraCu-richCIGSlayerwiththethicknessfrom100nmto200nmisgrownonthesubstrate,andthenanotherCu-poorCIGSfilmwiththicknessof1.5-2.0μmisdepositedonit.Withthemodificationoftheevaporationprocess,thegrainsizeofabsorberlayerisincreased,andtheadditionalsecondaryphasesalmostdisappear.Accordingly,theoveralldeviceperformanceisimproved,andtheconversionefficiencyisenhancedbyabout20%.

简介：Digitalsignatureisoneofthemostimportantcryptographicprimitives.WeproposedanewdigitalsignatureschemebasedonCatalano’strapdoor.SinceCatalano’strapdoorismoreefficientthanexistingtrapdoorsinnumbertheory,ourschemeneednotmodularexponentiationbutseveralmodularmultiplicationsinthesigningalgorithm.Wealsoprovedourschemeisprovablysecureagainstadap-tivelychosenmessageattackbyusingtheForkinglemma.

简介：CRTCornercuttingtubeisconsideredasadefinitiverejectandwillbesenttoreclaimatalltimes.Itcausedlotsofmaterialloss.Inthispaper,anoveltechnologyusedtosaveCRTscornercuttingtubeispresentedfirstly.AsetofrepairsystemhasbeensuccessfullydevelopedtorepairCRTscornercuttingtube.Then,theprocesstechnologyforcornercuttingrepairhasbeenexcogitatedbyempiricalstudies.Finally,thecorrelativeperformancesofrepairedtubeareevaluated.Theexperimentalresultsshowthatthequalityofrepairedtubehasnodifferencewiththatofnormalproduct.Therepairyieldhasreachedabove97percent.Thisnewtechnologyhascontributedtoimprovingtheproductionyield,reducingthematerialconsumptionanddecreasingthecostofcolorCRTproduction.

简介：Thisletterintroducesthedesignideas,simulationandtestresultsofanS-bandklystronwithbandwidthof11%,whichwasdevelopedbytheInstituteofElectronics,ChineseAcademyofSciences(IECAS).Onthepeakpowerlevelof800kW,theefficiencyofklystronismorethan30%;thegainismorethan41dB;theequal-drivingrelativeinstantaneousbandwidthisover11%;theaveragepowerislargerthan8kW,andthepowerfluctuationwithinbandwidthislessthan1.5dB.

简介：ThecharacteristicofEDFAinWDMsystemisanalyzed.ThesimulationsystembasedonthearchitectureoftheChinaInformationNetwork(CAINONET)isintroduced,andtheinfluenceofnoisefigure,gainunflatnessandoutputpowerofEDFAontheBERperformanceandscaleofnetworkisinvestigated.Moreover,theinfluenceofnoisefigureisstudiedwithdifferentcrosstalk.Meanwhile,itisindicatedthatitisimportanttoapplythe"nodeisolationprinciple"intheopticalnetwork.Theresearchresultscanprovidethevaluablereferenceforthepracticalconstructionofallopticalnetwork.

简介：在转向无铅电子产品过程中，元件供应商可能需要支持无铅和合铅元件的双线生产。而这可能合在生产制造中引起广泛的后勤问题。全部使用无铅元件是这个问题的一个解决方法。因此，用锡铅共晶焊膏粘接的Sn-Ag—CuBGA元件的焊点可靠性需加讨论。在这篇论文中介绍了对两种无铅封装：超细间距BGA(VFBGA)和层叠式CSP(SCSP)的焊点可靠性评估结果，它们是应用锡铅共晶焊膏贴在PCB板上。而这些封装都是采用不同的回流曲线在标准的锡铅组装条件下组装的。采用合保温区或斜升区的热度曲线。回流峰值温度为208℃和222℃。组装后PCB(称为板级)进行温度循环(-40℃—125℃，每个循环30分钟)和落体实验。下面将会详细叙述失效分析。

简介：ThislettergivesarandomconstructionforLowDensityParityCheck(LDPC)codes,whichusesaniterativealgorithmtoavoidshortcyclesintheTannergraph.TheconstructionmethodhasgreatflexiblechoiceinLDPCcode'sparametersincludingcodelength,coderate,theleastgirthofthegraph,theweightofcolumnandrowintheparitycheckmatrix.ThemethodcanbeappliedtotheirregularLDPCcodesandstrictregularLDPCcodes.Systemiccodeshavemanyapplicationsindigitalcommunication,sothisletterproposesaconstructionofthegeneratormatrixofsystemicLDPCcodesfromtheparitycheckmatrix.Simulationsshowthatthemethodperformswellwithiterativedecoding.

简介：介绍了S波段极低噪声超导滤波放大组件的设计过程,采用了低温仿真建模和拓扑结构优化设计关键技术。该组件将用于接收系统中的的低温接收前端,能提高雷达的灵敏度和有效作用距离。该组件由超导滤波器和低温放大器组成,具有体积小、重量轻、可靠性高等特点。

简介：在有低极化模式的40个Gb/s系统分散(PMD)纤维，一阶的PMD是有相当小的价值的dominate因素。由一个电的极化控制器(PC)组成的一个适应PMD赔偿者，维持纤维(PMF)的极化的节，极化(DOP)的度察觉者和一个反馈控制模块在40Gb/sNSFCNet被采用。这个赔偿者有简单结构和高速度，它能适应地补偿一阶的PMD直到20ps，平均寻找时间是2ms。CLC数字TN929.11

简介：S模式ADS-B系统概念结合了自动相关监视和S模式信标雷达,是一种监视和数据链的综合系统,包括机载设备和地面设备,它是在S模式二次监视雷达的基础上发展起来的一种新型的空管监视系统,正逐步得到国际上的广泛应用。介绍了S模式ADS-B的原理及应用范围,并对其性能进行了详细的对比分析。

简介：Transmissionperformanceofelectroabsorptionmodulatorin10Gb/stransmissionsystemshasbeensimulatedandanalyzedundertheconditionoftakingintoaccountthechirp,extinctionratio,transmissivityandrise/falltime.ResultsshowthatshorttransmissiondistancewithoutEDFAafterEAMcanbeusedinfuturemetropolitanareanetwork,butthetransmissivitymustbecarefullyconsidered.Thesamplingtimerangeanddecisionlevelcanbeoptimizedtoreducethebiterrorratio.

简介：ItiswellknownthatthealgebraicexpressionofASSS-boxisverysimpleandonly9termsareinvolved.Hence,AESsecurityissuspectedalthoughthereisnovulnerabilityonitsofar.ToeliminatetheweaknessofextremelysmalltermsinthealgebraicexpressionofAESS-box,oneimprovedAESS-boxisproposed,whichpreservesthealgebraicdegreeinvariablebutsignificantlyincreasesthenumberofitsalgebraicexpressiontermsfrom9to255.Atthesametime,Booleanfunctionhasgoodcharactersinbalanceandstrictavalanchecriterion(SAC),etc.Finally,itisprovedthattheimprovedAESS-boxschemeissecuregainstthepowerfulknowndifferentialandlinearcryptanalysis.