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49 个结果
  • 简介:在已给q个定义于n维欧几里德空间的函数中求r个最大函数和的最小,其中1≤r≤q。该问题是非光滑最优化问题,不能直接用一阶最优化方法或梯度法求解。利用对偶理论将该问题转化为只包含最大函数max{0,t}的非光滑问题。运用对数一指数光滑函数,对该非光滑问题建立具有全局收敛的光滑化算法。该算法的收敛率是线性的。

  • 标签: r个最大函数和 非光滑问题 光滑化法
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  • 简介:利用多元函数极值的定义和偏导数的定义公式证明二元函数与一元函数在某点取得极值的关系.

  • 标签: 一元函数 二元函数 极值
  • 简介:介绍了函数奇偶性的定义和图像特征,分析了函数和与积的奇偶性变化,研究了复合函数的奇偶性特点等。函数是数学的研究对象,而函数的奇偶性是函数的四大特性之一。研究函数的奇偶性对解题和函数作图都很重要。

  • 标签: 函数 奇偶性 复合函数
  • 简介:AtMinisterHuangYicheng’sinvitation,Mr.Abaza,MinisterofEgyptianElectricityandEnergy,andhisdelegation,consistingofMrs.AbazaandothertwoEgyptianofficialspaidafriendlyvisittoChinafromApril17toApril24,1992.AfterdiscussingwithMr.Huang,Min-isterofenergy,the“MemorandumofTech-nicalCooperationinthefieldofElectricPowerbetweenthePeople’sRepublicofChinaandArabRepublicofEgypt”wassignedsuccessfully.Bothsidesagreedtohaveafurthercooperationinthefuture.Be-

  • 标签: MINISTER OFFICIALS VISIT cooperation agreed REPUBLIC
  • 简介:China'spowerconsumptionisexpectedtorise4percentto6percentyear-on-yearinthefourthquarterasthecountry'seconomyisstabilizing.Thatwillbringelectricityconsumptionintheentireyearto4.94TWh,up5percentfromayearearlier,theChinaElectricityCouncilsaidonOctober30.AccordingtoCEC,thecountry'stotalinstalledpowergenerationcapacitywillhit1.14TWhattheendofthisyear.Powerdemandandsupplywillbebalancedbecausethereare

  • 标签: 中国电力企业联合会 电力消费 消费量 用电量 经济
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  • 简介:CambodiaKiriro1stCascadeHydropowerStationisthefirstoverseasBOTprojectoftheStatePowerCorporation(SP).ItisareconstructionprojectwhichiscontractedbyChinaPowerTechnologyImport&ExportCompany(CPTIEC).OnDecember9,2000,theagreementonseller’sexportcreditloanconcernin

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  • 简介:ThispapersummarizesthebasicsituationofthewindpowerdevelopmentinChinain2008,andcarriesoutabriefanalysisoftheproportionofthenationwidewindpowertotheglobalwindsectoraswellastothetotalinstalledcapacityinthecountry.ByreviewingtheremarkableachievementsinChina'swindpowerdevelopmentsincetheenforcementoftheRenewableEnergyActofthePeople'sRepublicofChina,someissuesconcerningthepolicyeffectandwindpowerdevelopmentaretouchedon.

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  • 简介:PurchasetransactionsatgenerationsideIn2011,thepurchasetransactionsofelectricitycarriedoutbytheStateGridCorporationofChina(SGCC)amountedto3047TWhatgenerationside(powerplantsunderunifieddispatch),up12.6%onayear-on-yearbasis.Ofallthepurchasetransactions,2612TWhwerethermalpower,349.4TWhhydropower,41.2TWhwindpower,and44.4TWhwereotherpowersources.Thepurchasetransactionsofelectricityatthegenerationsideintenprovincial-levelgridstotaledmorethan100TWh.TheseincludetheNorthHebei,Hebei,Shanxi,Shandong,Jiangsu,Zhejiang,Fujian,Henan,Sichuan,andLiaoninggrids.ThepurchasetransactionsintheJiangsugridreached338.7TWh,rankingfirstamongallprovinces.NingxiaandXinjiangsawratherlargegrowthinthepurchasetransactionofelectricityatthegenerationside.ThegrowthrateinNingxiawas75%.Table1showsthepurchasetransactionsofelectricityatthegenerationsidein2011.

  • 标签: 国家电网公司 电力交易 年报 风力发电 交换数据 统一调度
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  • 简介:Fast-growingeconomyimposinghigherrequirementforenergyindustryDuringthe"TenthFive-YearPlan"period,China'sGDPgrewatanaverageannualrateof9.5%,andcorrespondinglythetotalvolumeofenergyconsumptiongrewatanaverageannualrateof10.5%.

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  • 简介:近几年来出现了电机定子绕组采用间接冷却的明显趋势。汽轮发电机采用这种简单而经济的冷却方法可以增加单机容量,但是对定子绕组绝缘提出了新的更为严酷的要求。MicadurR-plus绝缘是一种改良的绝缘系统(在ABB公司开发的著名Micadur技术基础上发展起来的),其特点是不仅有良好的短期和长期使用特性,而且导热系数非常高。

  • 标签: 汽轮发电机 电机 定子绕组 绝缘系统
  • 简介:Low-voltageElectricalApparatus(LVEA)whichisakeylinkfortransmittingelectricalpowertousers,isconnectedbetweentransformerandloadmainlytobeusedfordistribution,pro-tection,controllingofelectricalcircuitsandalsoforstarting,adjusting,stoppingandindicatingofload.Thelow-voltageelectricalproductsincludeswitch

  • 标签: transmitting USERS STOPPING switch TRANSFORMER STARTING
  • 简介:OnApril28,110-kVtransmissionlinefromShengouSubstation(Guangxi,China)toMongCaiSubstation(Vietnam)smoothlystartedsendingelectricity.ThisisaninterconnectionprojectbetweenChinaandVietnam.Thelineruns4.7kminChinaand7.8kminVietnam.TheprojectbeganconstructioninFebruarythisyear.

  • 标签: 广西 跨国电力网 越南 工程建设
  • 简介:Theunit5ofHuangdaoPowerPlantwhichwasfinancedandbuiltbyQingdaoGuoxinIndustrialCo.,Ltd.carriedout168-hourtrialoperationonOctober24.Itsloadfactorreachedover98%.Alltheindexesoftrialoperationwereexcellent.Atpresent,theunitisinoperationundertheconditionsoffullprotection,fullautomationandfullload.

  • 标签: 中国 电力建设 自动化 超临界电压
  • 简介:由[a,b]上的勒贝格可测函数与几乎处处连续的函数几乎处处相等,给出勒贝格可测函数的等价定义及几个勒贝格可测函数的性质,提出一些关于勒贝格可测函数进入工科数学教学的设想。

  • 标签: 勒贝格可测函数 广义可去间断点 本性间断点