简介:InthispaperL^p-L^qestimatesforthesolutionu(x,t)tothefollowingperturbedhigh-erorderhyperbolicequationareconsidered,(ρπ--a△)(ρπ--b△)u+V(x)u=O,x∈R^n,n≥6,ρ1eu(x,O)=O,ρ^3eu(x,O)=f(x),(j=O,1,2).WeassumethattheotentialV(x)andtheinitialdataf(x)arecompactlysupported,andV(x)issufficientlysmall,thenthesolutionu(x,t)oftheaboveproblemsatisfiesthesameL^p-L^qestimatesasthatoftheunperturbedproblem.
简介:<正>InthispaperitisprovedthatforallcompletelydistributivelatticesL.thecategoryofL-fuzzifyingtopologicalspacescanbewmbeddedinthecategoryofL-topologicalspaces(stratifiedChang-Goguenspaces)asasimultaneouslybireflectiveandbicoreflectivefullsubcategory.
简介:WeconstructaclassofintegrablegeneralizationofTodamechanicswithlong-rangeinteractions.ThesesystemsareassociatedwiththeloopalgebrasL(Cr)andL(Dr)inthesensethattheirLaxmatricescanberealizedintermsofthec=0representationsoftheaffineLiealgebrasCr(1)andDr(1)andtheinteractionspatterninvolvedbearsthetypicalcharactersofthecorrespondingrootsystems.WepresenttheequationsofmotionandtheHamiltonianstructure.Thesegeneralizedsystemscanbeidentifiedunambiguouslybyspecifyingtheunderlyingloopalgebratogetherwithanorderedpairofintegers(n,m).Itturnsoutthatdifferentsystemsassociatedwiththesameunderlyingloopalgebrabutwithdifferentpairsofintegers(n1,m1)and(n2,m2)withn2<n1andm2<m1canberelatedbyanestedHamiltonianreductionprocedure.Forallnontrivialgeneralizations,theextracoordinatesbesidesthestandardTodavariablesarePoissonnon-commute,andwheneithernorm≥3,thePoissonstructurefortheextracoordinatevariablesbecomessomeLiealgebra(i.e.theextravariablesappearlinearlyontheright-handsideofthePoissonbrackets).Inthequantumcase,suchgeneralizationswillbecomesystemswithnoncommutativevariableswithoutspoilingtheintegrability.
简介:Weconsiderforafixedμ,theclassofpolynomialsPn,μ,s:=P(z)=zsanzn-s+n-s∑j=μan-jzn-j-s;1≤μ≤n-sofdegreen,havingallzerosin|z|≤k,k≤1,withs-foldzerosattheorigin.Inthispaper,wehaveobtainedinequalitiesinthereversedirectionfortheaboveclassofpolynomials.Besides,extensionsofsomeTuran-typeinequalitiesforthepolarderivativeofpolynomialshavebeenconsidered.
简介:AnefficientroutetoprepareL-glucoseandL-galactoseisdescribed.TheL-sugarsareachievedbyusingthestrategyofswitchingthefunctionalgroupsatC1andC5ofD-glucoseandD-mannose.TheoxidationandreductionofthesilylenoletheratC1andthelead(IV)tetraacetatemediatedoxidativedecarboxylationatC5arethekeysteps.L-GlucoseandL-galactosearepreparedinaconvenientandinexpensiveway.
简介:Lp-LqdecayestimateofsolutiontoCauchyproblemofalinearthermoviscoelasticsystemisstudied.Byusingadiagonalizationargumentoffrequencyanalysis,thecoupledsystemwillbedecoupledmicrologically.Thenwiththehelpoftheinformationofcharacteristicrootsforthecoefficientmatrixofthesystem,Lp-LqdecayestimateofparabolictypeofsolutiontotheCauchyproblemisobtained.
简介:摘要目的分析Prader-Willi综合征(PWS)患儿在围生期的临床特点,提高对本病的早期识别。方法横断面研究。2019年9月至2020年3月由中国医学科学院北京协和医学院北京协和医院儿科在全国范围内入组经分子遗传学诊断明确的PWS患儿226例,收集临床资料包括出生胎龄、出生体重、胎动情况、胎位情况、羊水情况、出生方式、哭声、肌张力、喂养以及男性患儿是否存在隐睾等,分析中国PWS患儿围生期的临床特点,并根据出生方式、是否小于胎龄儿以及基因型进行亚组分析。对不同亚型的临床表现通过t检验、χ²检验和Mann-Whitney U检验进行统计学分析。结果226例PWS患儿中男120例、女106例,小于胎龄儿有100例(44.2%)。最常见宫内表现为孕期胎动减少202例(89.4%),其他表现包括羊水增多71例(31.4%)、胎位异常58例(25.7%),共有185例(81.9%)患儿经剖宫产出生,且剖宫产出生的患儿更常伴有胎位异常表现[30.8%(57/185)比 2.4%(1/41),χ²=14.161,P<0.01]。患儿出生后的异常表现则包括肌张力低下221例(97.8%)、哭声弱220例(97.3%)、男性隐睾116例(占全部120例男性患儿的96.7%)及喂养困难206例(91.2%)。父源缺失型有184例(81.4%),非缺失型患儿的母亲怀孕年龄相较于父源染色体缺失型的患儿母亲更大[(35±5)比(29±5)岁,t=-6.591,P<0.01],也更易在孕期出现羊水过多的表现,差异均有统计学意义[47.6%(20/42)比27.7%(51/184), χ²=6.286,P=0.012]。结论PWS患儿围生期的主要表现为肌张力低、哭声小、喂养困难、宫内胎动减少以及男性隐睾,并且行剖宫产出生的概率高。对有以上特征的新生儿,儿科医生应注意到PWS的可能性。基因型与表型关系方面,非缺失型PWS患儿更容易有羊水过多的表现。