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500 个结果
  • 简介:WeinvestigateindetailtheeffectsofR-parityleptonnumberviolationonthedecay~↑b1b~↑x1^0intheR-parityviolatingminimalsupersymmetricstandardmodel(Rp-MSSM)underthepresentexperimentalconstraintsonRpparameters.Inournumericalcalculationsweconsidertwocasesofinputparametersofthesquarkandsleptonsectors,MsquarkMslepton,forcomparison.TheresultsshowthattherelativeR-parityviolatingcorrectionisnotverysensitivetothemassofthelightestneutralino-0↑x1andthedegenerateR-parityviolatingcouplingparameterλ2′,butstronglydependsonMsquark,Mslepton,tanβandthedegenerateR-parityviolatingcouplingparameterλ1′.Therelativecorrectionisabout-4~3%andcanexceed-6%insomeregionofparameterspace.Therefore,preciseexperimentanalysesonthedecay~↑b1b~↑x1^0mayprovideaprobeoftheR-parityviolation.

  • 标签: R-奇偶效应 最小超不对称模型 质子 稳定性 重子数
  • 简介:LetMbeapositivequaternionicKhlermanifoldofdimension4m.Wealreadyshowedthatifthesymmetryrankisgreaterthanorequalto[m/2]+2andthefourthBettinumberb_4isequaltoone,thenMisisometrictoHP~(m).Thegoalofthispaperistoreportthatwecanimprovethelowerboundofthesymmetryrankbyoneforhighereven-dimensionalpositivequaternionicKahlermanifolds.Namely,itisshowninthispaperthatifthesymmetryrankofMwithb_4(M)=1isgreaterthanorequaltom/2+1form≥10,thenMisisometrictoHP~m.OneofthemainstrategiesofthispaperistoapplyamoredelicateargumentofFrankeltypetopositivequaternionicKhlermanifoldswithcertainsymmetryrank.

  • 标签: 四元数 流形 高功率微波 对称约束 分类 高等级
  • 简介:首先运用Phillips定理和Fattorini定理证明M/Mk,B/1排队模型概率瞬态解的存在唯一性,然后通过研究对应于M/Mk,B/1排队模型的主算子的共轭算子的豫解集得到该主算子的豫解集:在虚轴上除了零点外其它所有点都属于该主算子的豫解集.

  • 标签: Dispersive算子 保守算子 共轭算子
  • 简介:Inthisarticle,wecalculatethecontributionfromthenonfactorizablesofthadronicmatrixelementtothedecayB~0→χc1~π~0withthelight-conequantumchromo-dynamic(QCD)sumrules.Thenumericalresultsshowthatitscontributionisratherlargeandshouldnotbeneglected.Thetotalamplitudesleadtoabranchingfractionwhichisinagreementwiththeexperimentaldatamarginally.

  • 标签: QCD求和规则 衰变 计算结果 强子矩阵元 实验数据 动力学
  • 简介:Afacileandconvenientsynthesismethodhasbeendevelopedforsubstitutedquinoxalinesand2H-benzo[b][1,4]oxazinesfromthereactionsofα-bromoketoneswithbenzene-1,2-diamineand2-aminophenol,respectively,whichwerecatalyzedbytetrabutylammoniumbromide(TBAB)inaqueousbasicmedia.

  • 标签: 简便合成 水溶液 四丁基溴化铵 合成方法 氨基酚
  • 简介:DrugsSPD-304(6,7-dimethyl-3-{[methyl-(2-{methyl-[1-(3-trifluoromethyl-phenyl)-1H-indol-3-ylmethyl]-amino}-ethyl)-amino]-methyl}-chromen-4-one)andzafirlukastcontainacommonstructuralelementof3-substitutedindolemoietywhichcloselyrelatestoadehydrogenatedreactioncatalyzedbycytochromeP450s(CYPs).ItwasreportedthatthedehydrogenationcanproduceareactiveelectrophilicintermediatewhichcausetoxicitiesandinactivateCYPs.DrugL-745,870(3-{[4-(4-chlorophenyl)piperazin-1-yl]-methyl}-1H-pyrrolo2,3-β-pyridine)mighthavesimilareffectsinceitcontainsthesamestructuralelement.Weusedmoleculardockingapproachcombinedwithmoleculardynamics(MD)simulationtomodelthree-dimensional(3D)complexstructuresofSPD-304,zafirlukastandL-745,870intoCYP3A4,respectively.Theresultsshowthatthesethreedrugscanstablybindintotheactivesiteandthe3-methylenecarbonsofthedrugskeepareasonablereactivedistancefromthehemeiron.ThecomplexstructureofSPD-304-CYP3A4isinagreementwithexperimentaldata.Forzafirlukast,thecalculationresultsindicatethat3-methylenecarbonmightbethedehydrogenationreactionsite.DockingmodelofL-745,870-CYP3A4showsapotentialpossibilityofL-745,870dehydrogenatedbyCYP3A4at3-methylenecarbonwhichisinagreementwithexperimentinvivo.Inaddition,residuesinthephenylalanineclusteraswellasS119andR212playacriticalroleintheligandsbindingbasedonourcalculations.ThedockingmodelscouldprovidesomecluestounderstandthemetabolicmechanismofthedrugsbyCYP3A4.

  • 标签: 分子对接 甲基吲哚 药物 细胞色素P450 脱氢反应 结构元素
  • 简介:<正>我们通常通过"数形结合"的方法判断过定点的直线与双曲线x2/a2-y2/b2=1能否相切,强调对图形的感知能力。本文拟用严格的代数方法说明定点与双曲线的位置关系对切线条数及切点位置的影响。

  • 标签: x~2/a~2 y~2/b~2 数形结合 代数方法 平面直角坐标系 恒成立
  • 简介:Underinvestigationinthispaperisa(3+1)-dimensionalvariable-coefficientKadomtsev–Petviashviliequation,whichdescribesthepropagationofsurfaceandinternalwaterwaves.ByvirtueofthebinaryBellpolynomials,symboliccomputationandauxiliaryindependentvariable,thebilinearforms,solitonsolutions,B¨acklundtransformationsandLaxpairareobtained.Variablecoefficientsoftheequationcanaffectthesolitonicstructure,whentheyarespeciallychosen,whilecurvedandlinearsolitonsareillustrated.Elasticcollisionsbetween/amongtwoandthreesolitonsarediscussed,throughwhichthesolitonskeeptheiroriginalshapesinvariantexceptforsomephaseshifts.

  • 标签: LAX对 变系数 孤立波解 方程 BACKLUND变换 双线性形式
  • 简介:关于递推数列Xn+=(axn+)/(cxn+d)的极限的注记田文平(南京审计学院)关于递推数列Z.+l一;;=:一的极限.文D」给出了下面两个结论:”—”——“”””“”-x+d”“”’””““-“”“““’””“’—””“”结论设数列?..

  • 标签: 递推数列 极限 充分必要条件 通项公式 线性递归方程 共轭复根
  • 简介:Thetitlecomplexi-C4H9Co(salen)(Py)(Py=pyridine.salen=dianionofdisalicylideneethylenediamine)hasbeenfirstsynthesized.ItscrystalstructurehasbeendeterminedbyX-raydiffractionmethod.ThecrystsisaremonoclinicwithspacegroupP21/C.Theunitcellparametesarepresented.ThestructurehasbeenrefinedtoafinalRof0.038.

  • 标签: refined PYRIDINE MONOCLINIC compl alkyl DALTON
  • 简介:摘要高压断路器是电力系统中重要的控制设备,其运行的可靠性不仅关系到高压断路器本身,而且影响到其他设备乃至整个电网。本文以LTB145D1/B型SF6断路器为例,简要总结了其解体检修流程,掌握这些工艺环节对检修人员尤为重要。

  • 标签: SF6断路器 解体检修
  • 简介:Thereisagrowingsupportforthelowlyingscalarmesonsf0(500),f0(980),a0(980),and(800)tobegenerateddynamicallyfromtheinteractionofpseudoscalarmesons,whilethecaseofthenextsetofscalarresonancesathigherenergies,f0(1370),f0(1710),K0(1430)ismoreaquestionofdebate.Soisthecaseofthetensorresonancesf2(1270),f′2(1525),K2(1430).AnewperspectiveonthesestateshasbeenofferedinRef.[1]wherethef0(1370)andf2(1270)resonancesareshowntobegeneratedfromtheinteractionprovidedbythelocalhiddengaugeLagrangiansimplementingunitarization.Itisshownthattheideaofthenatureofthesestatesasvectormeson-vectormesoncompositestateshasbeentestedinmanyreactions.Yet,thepermanentdiscussionoftheissuedemandsextrachecksforotherobservablesand,inthissense,theweakdecaysbringanewsourceofvaluableinformationthatshouldservetotestdifferentmodels.

  • 标签: J/Ψ source case SENSE NEXT IDEA