简介:以杭州曲院风荷景点为研究对象,以历史文献为线索,结合山水画、版画、照片、测绘图等图像资料,梳理其景观格局变迁历程,分析演变中景物间的联系,并对各时期园林发展情况进行总结。将其发展历程划分为南宋麯院时期、元代至明代衰落时期、清代更址重建时期及中华人民共和国成立至今的公园化时期。认为清康熙年间曲院的迁址与更名是景点发展的重要转折点,这一举动既使古老的景名得以延续,又使景点有了新的内涵和发展空间。园林建筑与环境的营造围绕"曲"这一主题展开,代表人工的"曲院"与代表自然的"风荷"体现了该景点人工建筑与自然景物并重的审美主旨。通过分析整理历史图像资料对于今人了解古代园林变迁有重要帮助。
简介:Wedemonstrateanall-fiberhigh-powerYb-doped1018nmfiberlaserwithaGaussian-shapedoutputbeamprofilebasedonamismatchedstructure,whichconsistsofapairofsingle-modefiberBragggratingsandasectionoffew-modedouble-claddinggainfiber.Theoutputpowerisupto107.5Wwithanoptical-to-opticalefficiencyof63%,andthe3dBbandis0.26nmatthispowerlevel.Suchastructureofsingle-mode–few-mode–single-modefiberoscillatorcanbeusedtogeneratehigh-powernarrow-linewidthlasingwithexcellentbeamqualityinotherspectralranges.
简介:摘要目的对老年慢性肺心病患者的临床表现、治疗方式进行调查。方法选择我院2013年2月-2015年2月间127例老年慢性肺心病患者,对所有患者的临床资料进行回顾性分析调查,了解患者疾病临床表现和治疗方式,并对患者的治疗效果进行收集、整理。结果所有患者临床表现为咳嗽、咳痰、喘息,痰黄黏稠;患者活动时症状会加重,心悸、气短情况也会加重,甚至会出现呼吸困难表现。查体可见患者口唇、指甲发绀,肺部听诊闻及湿罗音,颈静脉怒张,可存在肝肿大表现,患者肝静脉回流征阳性,双下肢可触及凹陷性水肿。127例患者经过治疗后有43例患者病情完全改善,达到临床治愈标准,占比例的33.9%;有69例患者治疗后症状有所改善,病情好转,占比例的54.3%;有10例患者治疗后病情无明显改善,占比例的7.9%;有5例患者死亡,占比例的3.9%。结论在治疗慢性肺心病时要对感染进行控制,同时要控制并发症发生,降低患者死亡率。
简介:Wereportonthehigh-poweramplificationofa1064nmlinearlypolarizedlaserinanall-fiberpolarizationmaintainedmasteroscillatorpoweramplifier,whichcanoperateatanoutputpowerlevelof1.3kW.Thebeamquality(M~2)wasmeasuredtobe<1.2atfullpoweroperation.Thepolarizationextinctionrateofthefiberamplifierwasmeasuredtobeabove94%beforemodeinstabilities(MIs)setin,whichreducedtoabout90%aftertheonsetofMI.ThepowerscalingcapabilityofstrategiesforsuppressingMIisanalyzedbasedonasemianalyticalmodel,thetheoreticalresultsofwhichagreewiththeexperimentalresults.ItshowsthatmitigatingMIbycoilingthegainfiberisaneffectiveandpracticalmethodinstandarddouble-claddinglargemodeareafiber,and,bytightcoilingofthegainfibertotheradiusof5.5cm,theMIthresholdcanbeincreasedtothreetimeshigherthanthatwithoutcoilingorloosecoiling.Experimentalstudieshavebeencarriedouttoverifytheidea,whichhasprovedthatMIwassuppressedsuccessfullyintheamplifierbypropercoiling.
简介:Thispaperisdevotedtotheanalysisandcomparisonofeco-civilizationconstructionmodesinChinaandmajordevelopedwesterncountries,whichmainlyfocusesonthetypicaladvancedrelatedecocivilizationconstructionmodesindifferentcountries,citiesorcounties.Finally,itmakesacomparativeanalysisathomeandabroad,drawstheconclusionandputsforwardsomemaincountermeasuresandsuggestionsforChina’seco-civilizationconstructiononthebasisoftheexistingresearch.
简介:WestudyspectroscopicsignaturesofamonochromaticbosonmodeinteractingwithaT-shapedoublequantumdotcoupledbetweenthemetallicandsuperconductingleads.Focusingonaweakinterdotcoupling,wefindthattheproximityeffecttogetherwiththebosonicmodeareresponsiblefortheseriesofFano-typeresonancesappearingsimultaneouslyatnegativeandpositiveenergies.WeinvestigatetheseinterferometricfeaturesanddiscusstheirinfluenceonthesubgapAndreevconductancetakingintoaccountthecorrelationeffectsdrivenbytheCoulombrepulsion.
简介:我们为f(T)严肃理论在宇宙论的限制的精确上探索SandageLoeb(SL)测试的影响。因为它在远类星体的系列在Lyman-森林里测量redshift飘移,SL测试是对当前的宇宙论的观察的重要补充,盖住2z的redshift沙漠5。避免数据矛盾,当模仿30的基准的模型嘲笑SL测试数据,我们基于当前的联合观察数据使用最好合适的模型。我们确定为f(T)严肃理论的参数评价上的这些SL测试数据的影响。二个典型f(T)模型被考虑,幂定律模型f(T)PL和指数形式的模型f(T)终止。结果证明SL测试罐头有效地打破存在在在另外的宇宙论的观察的今日的事密度m和小瘤常数H0之间的强壮的退化。为考虑f(T)模型,SL测试的30年的观察能极其改进m和H0的限制精确,但是不能有效地改进模型参数的限制精确。
简介:Propagationpropertiesofhigh-powerfiberlaserwithhigh-order-mode(HOM)contentarestudiednumericallyforthefirsttimetothebestofourknowledge.TheeffectofHOMonthepropagationpropertyisevaluatedbythepowerinthebucket(PIB)metric.ItisshownthatPIBismainlydependentonHOMcontentratherthantherelativephasebetweenthefundamentalmodeandHOM.ThePIBinvacuumismorethan80%whenthepowerfractionoftheHOMiscontrolledtobelessthan50%at5km.Therelativephasehasanimpactonthepeakintensitypositionandconcentrationofthefar-fieldintensitydistribution.Ifanadaptiveopticssystemisusedtocorrectthepeakintensitydeviation,theresultsindicatethatthereexistsamaximalvalueofPIBasrelativephaseincreases.Sucheffectisweakenedwhenpropagatinginturbulence.ComparedtothelaserbeamswithoutHOM,laserbeamswithHOMcontentarelessinfluencedbytheturbulenceandcanreduceaverageintensityfluctuation.Theresultsmaybeusefulinthedesignofahigh-powerfiberlasersystem.