简介:Thelocalpressuredistributionsandresistancecoefficients(f1andf2)throughthesharp180degturninarelativelyshort(L/De=4)two-passsmoothandrib-roughenedchannelwereinvestigatedforaReynoldsnumberrangeof1.0×10^3,9.0×10^3.Theribpitch-to-herghtratios(p/e)were5,10,and20,Theribheight-to-hydraulicdiamterratios(e/De)were0.025,0.050and0.10,andtheribanglesofattack(a)were90,45,60,-45,and-60deg.Ridswereinstallednotonlyinbeforeandafterturnregionsbutalsointurnregion.TheresultsshowthatresistancecoefficientsremainapproximatelyconstantwhenReynoldsnumberismorethan3.0×10^4,Theeffectsoftheribconfiguration(ribspacing,ribheight,andriborientation)ontheinletstraightductresistancecoefficient(f2)weresignificant,however,theireffectsontheoverallresistancecoefficient(f1)weredilutedbythesharp-180turn.Forthisrelativelyshortchannel(L/De=4),theoverallresistancecoefficient(f1)wasgreatlyaffectedbythesharpturn.Correlationsfortheoverallresistance(f1)andinletstraightductresistancecoefficient(f2)arepresented.
简介:根据圆波导模式耦合理论,设计了一种结构紧凑型高功率容量弯曲圆波导,计算得到了TE_(11)模式和TM_(01)模式高传输效率时圆波导半径与波导弯曲半径、传输效率与弯曲角度之间的关系。软件仿真结果表明:中心频率为9.7GHz时,弯曲圆波导对水平极化的TE_(11)模式、垂直极化的TE_(11)模式和TM_(01)模式可实现大于99.9%的传输效率。按照击穿阈值为1Mv·cm~(-1)计算,弯曲圆波导功率容量可达4GW。低功率测试表明:9.7GHz时,水平极化的TE_(11)模式、垂直极化的TE_(11)模式和TM_(01)模式的传输效率为99%,与理论模拟结果一致。
简介:CTAB/TX-100microemulsion-basedgel(MBG),whichcouldbesoakedinaqueoussolutionforalongtimewithoutmechanicalstrengthandshapechanges,wassuccessfullyprepared.LipaseimmobilizedinthisgelhadahigheractivitythanthatinCTABMBGwhencatalyzedtheesterificationreactionbetweenn-hexanoicacidandn-octanolanditsenantioselectivitywasslightlyhigherwhencatalyzedthestereoselectiveesterificationreactionbetweenracemicibuprofenandn-octanol.Inaqueoussolution,lipaseinCTAB/TX-100MBGcouldcatalyzesmoothlythehydrolysisreactionofoliveoilandcouldbereusedmanytimeswithouttheevidentchangeofMBGmechanicalstrengthalthoughitsactivitydecreased41.8%afternine-timerecycles.
简介:ThetreatmentofsalicylicacidmanufacturingwastewaterbyNDA-100resinwasinvestigated.ThesorptionintensityofphenolwasfoundtobestronglydependentonpHoftheaqueousphase.EquilibriumadsorptiondatafittobothLangmuirandFreundlichmodels.ThecolumnadsorptionshowedthatthisprocesswassuitableforthetreatmentofsalicylicacidmanufacturingwastewaterAbout99.9%CODcrremovalwasobtainedundertheoptimaloperatingconditions.Theresincouldbecompletelyregeneratedwith1BV8%(w/w)NaOH+2BVH2O,therecoveryof98.9%ofthesubstancewasreached.Thisprocessmakesitpossibletorecoverthevaluablematerialfromthewastewaterandtoimprovetheeffluentwaterquality.
简介:设G是一个有限的简单连通图.D(G)表示V(G)的一个子集,它的每一个点至少有一个最大匹配不覆盖它.A(G)表示V(G)-D(G)的一个子集,它的每一个点至少和D(G)的一个点相邻.最后设C(G)=V(G)-A(G)-D(G).在这篇文章中,下面的被获得.(1)设u∈V(G).若n≥1和G是n-可扩的,则(a)C(G-u)=和A(G-u)∪{u}是一个独立集,(b)G的每个完美匹配包含D(G-u)的每个分支的一个几乎完美匹配,并且它匹配A(G-u)∪{u}的所有点与D(G-u)的不同分支的点.(2)若G是2-可扩的,则对于u∈V(G),A(G-u)∪{u}是G的一个最大障碍且G的最大障碍的个数是2或者是|V(G)|.(3)设X=Cay(Q,S),则对于u∈Q,(a)A(X-u)==C(G-u)和X-u是一个因子临界图,或者(b)C(X-u)=和X的两部是A(X-u)∪{u}和D(X-u)且|A(X-u)∪{u}|=|D(X-u)|.(4)设X=Cay(Q,S),则对于u∈Q,A(X-u)∪{u}是X的一个最大障碍且X的最大障碍的个数是2或者是|Q|.更多还原
简介:Co(II)-salenwasencapsulatedinMIL-100(Cr)metalorganicframeworkby"shipinabottle"tosynthesizeanewelectrocatalyst,Cosalen@MIL-100(Cr).ThematerialwascharacterizedbyXRD,FT-IR,UV-VisandN2-adsorption.TheCosalen@MIL-100(Cr)modifiedglassycarbonelectrodeexhibitsawell-definedreductionpeakatthepotentialof–0.21Vtowardtheoxygenreductionreaction(ORR)bycyclicvoltammetry(CV)inpH=6.84phosphatebuffer.Almost400mVpositiveshiftofpotentialatCosalen@MIL-100(Cr)modifiedelectrodeforORRcomparedwiththatatbareglassycarbon,indicatesthatCosalen@MIL-100(Cr)possessesexcellentelectrocatalyticactivity.ThetransferrednumberofelectronsforORRwasdeterminedbychronocoulometry.TheresultsuggeststhattheintroductionofCo(II)-salencomplexintoMOFincreasestheelectrocatalyticactivityviaafour-electronreductionpathway.Furthermore,thiselectrocatalystexhibitsgoodstabilityandreproducibility.