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1.
三面角的棱面角的计算公式 总被引:1,自引:1,他引:0
定理 在三面角S—A1 B1 C1 中 ,三个面角∠C1 SB1 =α ,∠A1 SC1 =β ,∠A1 SB1 =γ ,且棱SA1 和平面C1 SB1 所成棱面角为θ1 ,棱SB1 和平面A1 SC1 所成棱面角为θ2 ,棱SC1 和平面A1 SB1 所成棱面角为θ3,则cosθ1 =cos2 β cos2 γ- 2cosαcosβcosγsinαcosθ2 =cos2 γ cos2 α- 2cosαcosβcosγsinβcosθ3=cos2 α cos2 β- 2cosαcosβcosγsinγ(三面角的棱面角余弦公式 )证明 如图 .在SA1 上取一点P ,作PQ⊥平面B1 SC1 … 相似文献
2.
§ 1.Introduction In [1 ],theauthordefinedaccuratelytheDrazininverseofamorphism .Previously ,somenecessaryandsufficientconditionswereobtainedforamorphismwith (epic ,monic)factorizationtohavethegroupinverse (see [2 ],Theorem 1 )andtheDrazininverseofamatrixoverthecomp… 相似文献
3.
Inthispaper,allspacesareregularandT1,andallmappingsarecontinuousandonto .Readersmayreferto [1 ]forunstateddefinitions. Quiterecently ,somecharacterizationsforcertainL imagesofparacompactlocallycompactspaceshavebeenobtainedin [2 ] .Similarly ,wecanestablishthech… 相似文献
4.
§ 1 IntroductionThispaperisthesequelto[1 ,2 ].Cairnsetal.[1] introducedthenotionofachaoticgroupactionasageneralizationofchaoticdynamicalsystems(seedefinitionbelow) .Theyshowedthatthecircledoesnotadmitachaoticactionofanygroup ,andconstructedachaoticactionofG =Z×… 相似文献
5.
几乎锥-次类凸向量集值优化的Benson真有效性 总被引:3,自引:0,他引:3
§ 1 IntroductionIn [1 ],Yang ,LiandWangintroducedanewclassofgeneralizedconvexset valuedfunc tions,termednearlycone subconvexlikefunctions.In [2 ],ChenandRongstudiedBensonproperefficiencyinvectoroptimizationwithgeneralizedcone subconvexlikevector valuedfunc tions… 相似文献
6.
§ 1.Introduction LetRnbendimensionalEuclideanspace,and (f1,… ,fm,Rn)acontractioniteratedfunctionsystem .Itiswellknownthatthereexistsauniquenon emptycompactsetEsuchthatE =∪mi=1 fi(E) .WecallthesetEinvarintsetfor (f1,… ,fm,Rn) . Let (f1,… ,fm,Rn)beacontractioniteratedfunct… 相似文献
7.
§ 1.Introduction LetMbeacompact 3 manifold .IfthereisaproperlyembeddedclosedsurfaceSinMwhichseparatesMintotwocompressionbodiesH1andH2 ,thenMcanbewrittenasM =H1∪SH2 .ThisstructureonMiscalledaHeegaardsplittingofMandSisasplittingsurface .H1∪SH2 issaidtobereducible… 相似文献
8.
In 1 982Lowen[1] introducedfuzzyneighbourhoodspaces .Sincethenthiskindofspaceshasbecomeanimportanttopicinfuzzytopology ,andalotofequivalentconditionsweregivenin [2 ],[3].Inthispaperwecharacterizethefuzzyneighbourhoodsystemsinafuzzyneighbourhoodspacebytheirlevelf… 相似文献
9.
一类具有总人口变化含时滞的SIS流行病模型分析 总被引:1,自引:0,他引:1
§ 1 IntroductionInanepidemiologicalmodel,iftherearemanydisease relateddeathsorthebirthsarenotbalancedbythedeaths,thenthepopulationsizemustbeassumedtobeafunctionoftime[1] .InSISepidemiologicmodels,susceptiblesbecomeinfectedaftersufficientcontactwithaninfec… 相似文献
10.
In 1 92 1 ,Bergmanintroducedakernelfunction ,whichisnowknownastheBergmankernelfunction .ItiswellknownthatthereexistsauniqueBergmankernelfunctionforeachboundeddomaininCn.ForwhichdomainscantheBergmankernelfunctionbecomputedbyexplicitformulas?Thisisanimportant… 相似文献