简介:缝线是影响除尘滤袋寿命及可靠性的重要因素之一,缝线在长期热烟气作用下失效的案例愈来愈引起业界的关注。通过热态拉伸试验研究了热蠕变性对袋式除尘器滤袋用PTFE缝线强力的影响。在持续高温下对PTFE缝线进行拉伸试验,结果表明:PTFE缝线的拉伸断裂强力随温度升高而大幅下降,试验温度在250℃以上时,其拉伸最大载荷仅1~3N(线密度1200~1250den);PTFE缝线的拉伸断裂伸长率随温度升高呈现先上升后下降的趋势,在120℃左右达到最大值;高温环境对PTFE缝线的使用寿命有较大影响,缝线能在软化后受到外力作用而断裂失效,在实际工业生产中应给予关注。
简介:Flexiblethin-filmsupercapacitorswithhighspecificcapacitancearehighlydesirableformodernwearableormicro-sizedelectricalandelectronicapplications.Inthiscontribution,Ni-Cohydroxides(NCH)nanosheetsweredepositedontopofNi-Cualloy(NCA)nanowirearraysformingafreestandingthin-filmcompositeelectrodewithhierarchicalstructureforsupercapacitors.Duringelectrochemicalcycling,thedissolutionofCuintoCuionswillcreatemoreactivesitesonNCA,andtheredepositedcopperoxidecanbecoatedontoNCH,givingrisetosubstantialincreaseinspecificcapacitancewithcycling.Meanwhile,NCAandNCHhaveexcellentconductivity,thusleadingtoexcellentrateperformance.Thisflexiblethin-filmelectrodedeliversanultrahighinitialspecificcapacitanceof0.63F·cm~(-2)(or781.3F·cm~(-3)).Duringcharge-dischargecycles,thespecificcapacitancecanincreaseupto1.18F·cm~(-2)(or1475F·cm~(-3))alongwiththe'self-etching'process.Theelectrodepresentsabetterspecificcapacitanceandratecapabilitycomparedwithpreviouslyreportedflexiblethin-filmelectrode,andthisnoveldesignofetchingtechniquemayexpandtootherbinaryorternarymaterials.
简介:Ni-dopedphenolresinwaspreparedwith1∶100massratioofNi(NO_3)_2·6H_2Otothermosettingphenolresintooptimizethestructureandpropertiesofpyrolyticcarbonderivedfromphenolresinandincreaseitscarbonyield.Thespecimenswerecuredat200℃andcarbonizedunderdifferentatmospheres(carbon-embeddedatmosphereandAratmosphere)andatdifferenttemperatures(600,800,1000and1200℃)for3h,respectively.Thecarbonyieldwasmeasured.ThermaldecompositioncharacteristicsofNi-dopedphenolresin,andtheoxidationresistance,phasecompositionandmicrostructureofpyrolyticcarbonwerecharacterizedbydifferentialscanningcalorimetry,X-raydiffraction,energydispersivespectroscopy,scanningelectronmicroscopyandtransmissionelectronmicroscopy.TheresultsshowthatthecarbonyieldofNi-dopedphenolresincarbonizedat800or1000℃isincreasedsignificantly,comparedwiththatwithoutanydopants.ThegraphitizationdegreeofpyrolyticcarbonstructurederivedfromNi-dopedphenolresinincreaseswiththeincreaseofcarbonizationtemperature.Themassivemulti-wallcarbonnanotubesof50-100nmindiameterandofmicrometrescaleinlengtharegeneratedat1000℃.Comparedwiththecarbonembeddedatmosphere,carbonnanotubescanbemoreeasilygeneratedinAratmosphere,resultinginhighercarbonyieldanddegreeofcrystallinityofthepyrolyticcarbonderivedfromNi-dopedphenolresin.TheoxidationresistanceofthepyrolyticcarbonderivedfromNi-dopedphenolresinat1200℃isimprovedsignificantlyanditshighestoxidationtemperatureisincreasedbyabout84℃,comparedwiththatfromNifreephenolresin.
简介:摘要本论文对LNG低温储罐用9Ni钢的焊接工艺进行了研究。通过制定不同的焊接工艺参数,进行焊接试验,对焊接接头的低温韧性、塑性和强度进行测试,研究结果表明经调质热处理和双相区热处理的9Ni刚的焊接接头的低温冲击韧性均能达到标准要求,且母材经双相区热处理的焊接接头的低温冲击韧性要优于母材经调质热处理的焊接接头;以ENiCrMo-6焊条为焊材的9Ni钢焊接接头具有较好的塑性;经调制热处理的母材强度低于焊缝,而经双相区热处理的母材强度与焊缝强度相近;以ENiCrMo-6焊条为焊材,采用交流焊接,焊接电流为70~120A,电压为19~24V,线能量为5kj/cm~18kj/cm的焊接工艺是可行的。
简介:ThetropicalPacifichasbeguntoexperienceanewtypeofElNio,whichhasoccurredparticularlyfrequentlyduringthelastdecade,referredtoasthecentralPacific(CP)ElNio.Variouscoupledmodelswithdifferentdegreesofcomplexityhavebeenusedtomakereal-timeElNiopredictions,buthighuncertaintystillexistsintheirforecasts.ItremainsunknownastohowmuchofthisuncertaintyisspecificallyrelatedtothenewCP-typeElNioandhowmuchiscommontoboththistypeandtheconventionalEasternPacific(EP)-typeElNio.Inthisstudy,thedeterministicperformanceofanElNio–SouthernOscillation(ENSO)ensemblepredictionsystemisexaminedforthetwotypesofElNio.EnsemblehindcastsarerunforthenineEPElNioeventsandtwelveCPElNioeventsthathaveoccurredsince1950.Theresultsshowthat(1)theskillscoresfortheEPeventsaresignificantlybetterthanthosefortheCPevents,atallleadtimes;(2)thesystematicforecastbiasescomemostlyfromthepredictionoftheCPevents;and(3)thesystematicerrorischaracterizedbyanoverlywarmeasternPacificduringthespringseason,indicatingastrongerspringpredictionbarrierfortheCPElNio.Furtherimprovementstocoupledatmosphere–oceanmodelsintermsofCPElNiopredictionshouldberecognizedasakeyandhigh-prioritytaskfortheclimatepredictioncommunity.
简介:摘要本文简要介绍了镍基合金的特点、分类和其在AP1000核电中的应用。以SB168UNSN06690镍基合金为代表,分析了Ni-Cr-Fe合金的焊接性,从焊接工艺特点和焊接接头性能方面分析了其焊接特点,针对焊接难点,总结了各难点的解决措施。并结合SB168UNSN06690的焊接性和工艺试验,总结了几点关于今后现场施工中应注意的建议。
简介:ThisLetterreportstheformationofperiodicsurfacestructuresonNi–Fefilmirradiatedbyasinglefemtosecondlaserpulse.Aconcavelenswithafocuslengthof-150mmisplacedinfrontofanobjective(100×,NA=0.9),whichtransformstheGaussianlaserfieldintoaringdistributionbytheFresneldiffraction.Periodicripplesformontheablationareaaftertheirradiationofasinglefemtosecondlaserpulse,whichdependsonthelaserpolarizationandlaserfluence.Weproposethattheringstructureofthelaserfieldleadstoasimilartransientdistributionofthepermittivityonthesamplesurface,whichfurtherlaunchesthesurfaceplasmonpolaritons.Theinteractionoftheincidentlaserwithsurfaceplasmonpolaritonsdominatestheformationofperiodicsurfacestructures.
简介:目的使用裸金属支架(BMS)和聚四氟乙烯(胛FE)覆膜支架行经颈静脉肝内门腔静脉支架分流术(TIPSS)治疗门静脉高压症患者临床疗效和技术设备成本对比分析。方法2010年5月~2015年6月对163例门静脉高压症患者行TIPSS术,患者平均年龄为(56±12)岁,女性占32.9%。其中接受BMS支架80例,接受覆膜支架83例。结果本组技术成功率为97.5%,术后门体梯度压从(16.1±4.8)mmHg下降至(5.1±2.1)mmHg;两组技术成功率和门体梯度压降无显著性差异;Kaplan—Meier分析显示,两组14d、6m和2a一期支架通畅率存在显著性差别,其中PTFE-覆膜支架组通畅率高;两组1a生存率和肝性脑病发生率无显著性差异;金属支架和覆膜支架总成本分别为66570元和70455元。结论TIPSS术是一种安全、有效的治疗门静脉高压症的方法。裸金属支架和PTFE-覆膜支架均具有良好的技术和临床效果,并发症发生率低。
简介:Toexaminetheeffectivenessofirondust-zeolitecompositeasanadsorbentfortheremovalofheavymetalionsfromaqueoussolutions,theadsorptionisotherms,thekinetic,thermodynamicandoptimumconditions,suchasinitialconcentration,pH,contacttime,adsorbentdosageandcompetitiveadsorptionconditionsofheavymetalswereinvestigated.ThecharacterizationofthecompositewascharacterizedviaFTIR,SEM,XRFandXRDmethods.Kineticresultsontheremovalofheavymetalionsfromaqueoussolutionshavebeenwelldescribedbythepseudo-second-ordermodel.TheadsorptiondataforCdandNiionswerefittedwellwiththeLangmuirandFretm-dlichisothermmodels,respectively.Themaximumadsorptioncapacitiesofirondust-zeoliteforCdandNiionswereequalto78.125and76.33mg/g,respectively.Thethermodynamicparameterssuchasenthalpy,entropyandfreeenergyofadsorptionofmetalionsweredetermined.Itwasfoundthattheprocessisendothermic,favorableandspontaneous.ThecompetitiveadsorptionabilityofheavymetalionsinthebinarysystemonthecompositeshowedthatCdionshadasynergisticeffectontheadsorotionofNiandNiionshadthenegativeeffectonCdadsorption.
简介:摘要对于高温、高压、临氢装置的TP321(国内为06Cr18Ni11Ti)奥氏体厚壁不锈钢钢管,由于其运行环境的特殊性,管道焊缝很容易产生晶间腐蚀,为了提高焊缝的抗高温腐蚀性能,焊后应进行稳定化热处理的工艺。本文对厚壁不锈钢管道焊缝稳定化热处理问题进行探讨,通过工艺评定和工程实践,成功解决了焊缝腐蚀问题。
简介:Inthisstudy,C_f/AlcompositesandTiAlalloyswerejoinedbyanewmethodnamedlaser-ignitedselfpropagatingsynthesis(SHS).Mixedpowdersof63.0Ni-31.9Al-5.1Ti(wt%)wereusedasjoininginterlayer.Perfectjointwasgot.ThemicrostructureevolutionandformationmechanismoftheSHSjointwereinvestigatedbyscanningelectronmicroscopy(SEM),energy-dispersivespectroscopy(EDS)andX-raydiffraction(XRD).Resultsshowthatlocalizedmeltingoccursonbothsides.Oneγ-Ni_(0.35)Al_(0.30)Ti_(0.35)andtwoNi-Alreactionlayersform,respectively,intheTiAl/interlayerandC_f/Al/interlayerinterfaces.ThecombustionofNi-Al-TiinterlayerbeginswiththesharpreactionofNiandAl.TheinterlayerproductisaeutecticorganizationofNiAlandAl-richγ.