简介:Thechangeofpinescale(HemiberlesiapitysophilaTakagi)populationdensityonpineforestinurbanparkbetweentreatment(tendingoperations)andCK(notendingoperations)wasresearchedinthispaper.Theresultswereshownasfollows:populationdensitydeclinedto0.63headperbundlefrom2.61headsperbundlewhencrowndensityofpineinurbanparkhadbecome0.5orsobymeansofcultivationactivitiessuchasfelling,pruningandthinningandsoon,anddropgotto75.86percent.Thepinewoodswouldsoongetrevivedonceusingthesecultivationactivities,sotendingoperationswasmainmeasurescontrollingoverharmofpinescaleinurbanpark;Atthesametime,populationdensityofpinescaleonpinewoodsinthesunnyslopewasmorethanthatinthesomberslopeandithadbecomelessandlessfromsunnyslopetosomberslope.Therefore,treespeciesmustbechosenintheplanninganddesignofurbanparkforpreventingharmandhappeningofpinescale.
简介:Inthispaper,aclassofsimilarcompositesystemsisdiscussed,whoseinterconnectionsareasymmetricalandmismatched.Theinterconnectionconditionisproposed.Basedonit,theinterconnectionsaredividedintotwoparts.Onesatisfiestheinterconnectioncondition,bymeansofthetwo--stepmethod,thedecentralizedcontrollersaredesigned.Theotherdoesnotsatisfytheinterconnectioncondition,butthisisoffsettedbygoodqualityofthesystemitself.Basedonthese,asufficientconditionisgivenbysomelinearmatrixinequalities,whichmakesthestudiedsystemsquadraticstabilevialineardecentralizedcontrollersbymakinguseoftheinformationofinterconnectionsbetter.
简介:Theeffectivenessofafluid-loadedsandwichedviscoelasticlayerinsuppressingacousticscat-teringandradiationhasbeenestimatedusingtheThomson-Haskellmatrixmethod.TheGU(GaunaurdandUberall)resonancetheoryhasbeenadoptedtohandlethreetypesofviscoelasticsubstrateswithair-filledin-clusions.Theeffectsofthevaryingthicknessofthesubstrates,thevolumefractionsoftheinclusionsandfre-quenciesofincidentwaveshavebeenstubbedtodeterminetheoptimalstrategiesofsignalreduction.Intheinvestigation,themonopoleresonancephenomenaoftheinclusionshavebeentakenintoaccount.
简介:BecausemodelswitchingsystemisatypicalformofTakagi-Sugeno(T-S)modelwhichisanuniversalapproximatorofcontinuousnonlinearsystems,wedescribethemodelswitchingsystemasmixedlogicaldynamical(MLD)systemanduseitinmodelpredictivecontrol(MPC)inthispaper.Consideringthateachlocalmodelisonlyvalidineachlocalregion,weaddlocalconstraintstolocalmodels.Thestabilityofproposedmulti-modelpredictivecontrol(MMPC)algorithmisanalyzed,andtheperformanceofMMPCisalsodemonstratedonaninulti-multi-output(MIMO)simulatedpHneutralizationprocess.
简介:Anovelrepetitivecontrolstrategyfortheoutputwaveformofsingle-phaseCVCFinvertersispresented.Inthisscheme,theinversetransferfunctionofinverterisusedasacompensatortoobtainstableandsatisfyharmonicrejection.Besides,PDcontrollerisadoptedtoimprovetransientperformance.Simulationandexperimentalresults,whicharegottenfromaDSP-based400Hz,5.5KWinverter,indicatethattheproposedcontrolschemecanachievenotonlylowTHDduringsteady-stateoperationbutalsofasttransientresponseduringloadstepchange.
简介:BackgroundThepowerindustryhaslongbeenplaguedwithcomplicationsandoutagesrelatedtocorrosionofplantcomponents.Priortothemid-sixties,corrosionofboilerwater-walltubeswasoneoftheprominentproblemsinpowerplants.Water-walltubescorrosionproceedingunderironoxidedepositcausedcausticgougingoracidicembrittlementoftubemetal.Manyboilertubesfailedbysuddenrupture.Fieldandlaboratorystudiesshowedthat,carbonatealkalinityandneutralsaltinboilermakeupwatertreated
简介:学术为本创建名校中国艺术研究院研究生院(原名研究生部)成立1978年,是国务院首批公布的博士、硕士学位授予单位,
简介:1960年8月15日国务院全体会议第102次会议通过,任命:徐英为外交部办公厅副主任,徐明为外交部苏联东欧司副司长,胡成放为外交部第一亚洲司副司长,柳雨峰为外交部领事司副司长,葛步海为外交部礼宾司副司长,李恩求为外交部条约法律司副司长;王近山为公安部副部长,余光文为公安部办公厅副主任,王一鸣为公安部第一局副局长,刘凯为公安部第二局副局长,马星五、郑惕为公安部第四局副局长,夏印为公安
简介:一、创建与修葺塔院寺,原与显通寺为一庙。正式独立是明代后期的事情。明万历七年(1579年),出于国家政治上的需要,由皇太后李氏出面,派遣太监范江、李友等人。赴五台山维修护国佑民释迦文佛舍利宝塔,即今天的大白塔。历时三年,不仅大规模地修葺、装饰了大白塔,而且围绕大白塔进行了重新规划布局,“寺宇佛殿经楼,藏轮禅宝,罔不备焉”(《清凉山志》)。明万历十年(1582年)七月,功成,举行了盛大的落成典礼。从此,塔院寺的名称正式注册,宣布独立。这次大规模动工,“计费金钱,出自内帑”(《清凉山志》),具体数字,惜未能知。据守内明万历十年七月九日碑记,当时山西