简介:TheNb-bromomethylderivative(2)ofgelsemine,aquaternaryammoniumsalt,wasfoundtoberecalcitranttowardHofmanntypealkalinedegradationwhichhasbeensuccessfulinothercases.Instead,are-distributionoftheN-methylgrouptookplace,givingriseto3a,1,3band3c,indescendingorderofRfvalues.
简介:Theβ-carboxylicgroupplaysanimportantroleinthepeptideformation,esterificationandtheesterexchangeatthephosphorylgroupofN-phosphorylatedasparticacid.
简介:Inthispaper,wegetW1,p(Rn)-boundednessfortangentialmaximalfunc-tionandnontangentialmaximalfunction,whichimprovesJ.Kinnunen,P.LindqvistandTananka’sresults.
简介:RemanspectroscopyisusedasatooltomonitorthereactionbetweenN,N’-di(pmethyl)monothioxamidesand1,3-diaminetrimethyleneandtodetectthereactionintermediate.Byobservingchangesof1024cm-1C=Sbandandappearanceofanewbendataround1720cm-1,thereactionmechanismisdiscussed.
简介:BytheSchauder-Tychonofffixed-pointtheorem,weinvestigatetheexistenceandasymptoticbehaviorofpositiveradialsolutionsoffullynonlinearellipticequationsinR^n.WegivesomesufficientconditionstoguaranteetheexistenceofboundedandunboundedradialsolutionsandconsiderthenonexistenceofpositivesolutioninR^n.
简介:Inthispaper,weconsiderthen-widthsandaveragewidthsofBesovclassesintheusualSobolevspaces.TheweakasymptoticresultsconcerningtheKolmogorovn-widths,thelinearn-widths,theGel'fandn-widths,intheSobolevspacesonT~d,andtheinfinite-dimensionalwidthsandtheaveragewidthsintheSobolevspacesonR~dareobtained,respectively.
简介:Introduction.Poly(N-vinylcarbazole)(PVCZ)hasreceivedmuchattentionasarepresentativephotoconductivepolymerandextensivestudiesonmechanical,physical,chemicalandelectricalpropertieshavebeenreported'’.Ingeneral,thePVCZobtainedbyradicalandordinarycanonpolym...
简介:求出了(n-3)-filiform李代数的极大环面,并证明了(n-3)-filiform李代数是可完备化的.
简介:AnexampleofcompletsRiemannianmetricofpositive(ornonnagative)curvatureonR^nsuchasds^2=a(x)dx^2isobtainedbydirectcaculations.Furthermore,byusingageodesicconvexconditionandatheoremforcompletenoncompactRiemannianmanifold,anexistenceresultofperiodicsulutionofprescribedenergyforasingularHamiltoniansystemisalsoobtained.