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500 个结果
  • 简介:凡是涉及到有关两个数之和、差与积的问题时,可考虑a2+b2=(a+b)22ab及其推出公式(a+b)2=(a±b)2+4ab.它们在解题中常常能获得出奇制胜的效果,可看以下几例.

  • 标签: 公式 应用 出奇制胜 个数
  • 简介:听下面5段对话。每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话读两遍。

  • 标签: 听力训练
  • 简介:猜猜搭档和年龄神探小子四人玩游戏,两人一组。现在告诉你:宁宁比峥嵘年龄小:伟栋比另一对搭档的年龄都大:宁宁比他的搭档年龄大:峥嵘与宁宁的年龄差距要比伟栋与奇奇的年龄差距大。请问:四人年龄从小到大的顺序是怎样的?谁和谁搭档?

  • 标签: 年龄差距 追踪 搭档
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  • 简介:令R是有1的结合环,本文中给出R上某些2×2块阵的群逆的存在性及表示.

  • 标签: 块阵 群逆
  • 简介:Anovelhighgravitymulti-concentriccylinderelectrodes-rotatingbed(MCCE-RB)wasdevelopedfortheelectrocatalyticdegradationofphenolwastewaterinordertoenhancethemasstransferwiththeself-madeRuO2-IrO2-SnO2/Tianodes.Theinfluencesofelectriccurrentdensity,inletliquidcirculationflowrate,highgravityfactor,sodiumchlorideconcentration,andinitialpHvalueonphenoldegradationefficiencywereinvestigated,withtheoptimaloperatingconditionsdetermined.Theresultsshowedthatundertheoptimaloperatingconditionscoveringacurrentdensityof35mA/cm^2,aninletliquidcirculationflowrateof48L/h,ahighgravityfactorof20,asodiumchlorideconcentrationof8.5g/L,aninitialpHvalueof6.5,areactiontimeof100min,andaninitialphenolconcentrationof500mg/L,theefficiencyforremovalofphenolreached99.7%,whichwasimprovedby10.4%ascomparedtothatachievedinthenormalgravityfield.Thetendencyregardingthechangeinefficiencyforremovalofphenol,totalorganiccarbon(TOC),andchemicaloxygendemand(COD)overtimewasstudied.Theintermediatesanddegradationpathwayofphenolwerededucedbyhighperformanceliquidchromatography(HPLC).

  • 标签: high gravity RuO2-IrO2-SnO2/Ti ANODE ELECTROCATALYTIC oxidation
  • 简介:Inpursuingexcellentsupercapacitorelectrodes,wedesignedaseriesofM0S2/C0S2compositesconsistingofflower-likedMoS2andoctahedron-shapedCoS2throughafacileone-stephydrothermalmethodandinvestigatedtheelectrochemicalperformanceofthesampleswithvarioushydrothermaltime.Duetothecouplingoftwometalspeciesandabigamountofwell-developedCoS2andMoS2,theresultsindicatedthattheMoS2/CoS2compositeselectrodesexhibitedthebestelectrochemicalperfor-mancewithalargespecificcapacitanceof490F/gat2mV/sor400F/gat10A/gamongallsamplesasthehydrothermaltimereached48h(MCS48).Furthermore,theretentionofMCS48is93.1%after10000cyclesat10A/g,whichmanifeststheexcellentcyclingstability.TheoutstandingelectrochemicalperformanceofMCS48indicatesthatitcouldbeaverypromisingandnovelenergystoragematerialforsupercapacitorsinthefuture.

  • 标签: MoS2/CoS2 COMPOSITES HYDROTHERMAL time ELECTROCHEMICAL properties
  • 简介:SATB2与SATB1同属于SATB家族,与SATB1高度同源性,SATB2作为与核基质附着区(MAR)结合的转录因子,可以同时激活多个基因的转录,而且SATB2是几个基因调控网络(GRN)的高级调控者,在多个发育过程中具有关键作用。SATB2参与骨骼系统的发育,SATB2表达异常会导致骨骼发育畸形。

  • 标签: SATB2 骨骼系统发育 神经系统发育 肿瘤
  • 简介:【上期回顾】赵萌萌找到周嘉怡的母亲.想让她母亲劝周嘉怡和秦墨分手.却没想到她的人生从此跌落谷底,因为她家老爷子说:“萌萌,你不是我的亲生女儿.赵嘉怡才是……”

  • 标签: 母亲 人生 女儿