共查询到20条相似文献,搜索用时 187 毫秒
1.
§ 1 IntroductionInthispaperwediscusstheglobalclassicalsolutionofamultidimensionalquasistationaryproblem .Theproblemcomesfromthediscussionofagrowthmodelofselfmaintainingprotocell(see [1— 3])inmultidimensionalcase .Theprotocellcanbevisualizedashavingaporousst… 相似文献
2.
§ 1.Introduction LetMbeacompact 3 manifold .IfthereisaproperlyembeddedclosedsurfaceSinMwhichseparatesMintotwocompressionbodiesH1andH2 ,thenMcanbewrittenasM =H1∪SH2 .ThisstructureonMiscalledaHeegaardsplittingofMandSisasplittingsurface .H1∪SH2 issaidtobereducible… 相似文献
3.
Zhang Guangxiang 《数学年刊B辑(英文版)》1996,17(4):411-420
§1.IntroductionZ.AradandH.Blauintroducedin[1]theconceptoftablealgebrasandusedthistodiscussthecharacteralgebraandthecentralclassalgebraofafinitegroupinauniformway.ThisideagoesbacktoI.Schur.AlittleextendednotionofC-algebraforeshadowedthedevelopmentofcommuta… 相似文献
4.
§ 1.Introduction Chainablecontinuahavebeenextensivelystudiedformanyyearsandhavegeneratednewinterestintherecentyearsasthechainablecontinuumwhichistheinverselimitspaceofacontinuousmapfromaclosedintervalintoitselfcanberealizedasaglobalattractorofsomeplan… 相似文献
5.
§ 1.IntroductionandMainResults ByameromorphicfunctionwealwaysmeanameromorphicfunctioninthecomplexplaneC .WeassumethatthereaderisfamiliarwithNevanlinnatheorythatcanbefound ,forinstance ,in [1 ] .Wesaythattwomeromorphicfunctionsfand gsharethevaluea∈ Cprovidedth… 相似文献
6.
《数学年刊B辑(英文版)》1996,(4)
1.TheChineseAnnalsofMathematics(CAM)Ser.Bisacomprehensivemathematicaljournalcarryingoriginalpapersonpureandappliedmathematics.Itaimsatpresentingthelatestachievementsinmathematicalresearchesandpromotingdomesticandinternationalacademicexchanges.2.CAMSer.Bis… 相似文献
7.
高中《代数》上册 (必修 )P1 50第 1 7题 :已知tanα =2 ,求sinα +cosαsinα -cosα的值 .此题虽浅显简单 ,但若能正确使用 ,对同学们培养能力 ,发展智力 ,引起兴趣 ,确能起到一定的作用 .1 一题多解解法 1 tanα =2 sinα =2 55,cosα =55.或 sinα =- 2 55,cosα =- 55.∴ sinα +cosαsinα -cosα=3 .解法 2 ∵tanα =2 sinαcosα=2 ,即sinα =2cosα ,∴ sinα +cosαsinα -cosα=2cosα +cosα2cosα -cosα=3 .解法 3 tanα=2 s… 相似文献
8.
§ 1.Introduction Intopologicalgraphtheory ,agraphmayhavemultipleadjacentiesandselfloops.Agraphiscalledsimplicialifithasnomultipleadjacenciesandselfloops .Asurfacehereisacompact2 manifoldwithoutboundary .Anembeddingofagraphiscellularifeachcomponentofthesur… 相似文献
9.
§ 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
10.
§ 1.Introduction Allgraphsconsideredinthispaperarefinite,undirected ,unloopedandsimplegraphs.WedenotethechromaticpolynomialofagraphGbyP(G ,λ)orP(G) .WesaygraphsGandHtobechromatiallyequivalentifP(G) =P(H) .ThechromaticuniquenessofagraphGisestablishedifitcanbeded… 相似文献
11.
ZhangZhengqiu WangZhicheng 《高校应用数学学报(英文版)》2001,16(4):355-363
The sufficient condition for the existence of non-constant periodic solutions of the following planar system with four delays are obtained: 相似文献
12.
Feng-de Chen Jin-lin Shi School of Mathematics Computer Fuzhou University Fuzhou China 《应用数学学报(英文版)》2005,21(1):49-60
With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, easily verifiable criteria are established for the global existence of positive periodic solutions of the following nonlinear state dependent delays predator-prey system where a_i(t),c_j(t),d_i(t) are continuous positive periodic functions with periodic ω>0, b_1(t),b_2(t) are continuous periodic functions with periodic ωand ∫_0~ωbi(t)dt>0. T_i,σ_j, p_i (i=1,2,…,n, j=1, 2,…,m) are continuous and ω-periodic with respect to their first arguments, respectively, α_i, β_j,γ_i(i=1,2,…,n, j=1,2, …, m) are positive constants. 相似文献
13.
李永昆 《应用数学学报(英文版)》1999,15(3):281-286
1.IntroductionNeutraldelayffereatialequationsinpopulationdynamicshavebeenstudiedextensivelyforthep88tfewyears.However,onlyafewpapersll--5]havebeenpublishedontheexistencesofperiodicsolutionsoftheneutraldelaypopulationmodels.In[6,7],Kuangproposedtoinve... 相似文献
14.
Global Existence of Positive
Periodic Solutions for a Distributed Delay Competition Model 总被引:3,自引:0,他引:3
Xian-yi Li De-ming ZhuDepartment of Mathematics East China Normal University Shanghai China Department of Mathematics Physics Nanhua University Hengyang China 《应用数学学报(英文版)》2003,19(3):491-498
By using the continuation theorem of Mawhin's coincidence degree theory, a sufficient condition is derived for the existence of positive periodic solutions for a distributed delay competition modelwhere ri and r2 are continuous w-periodic functions in R+=[0,∞) with ,ai,ci(i =1,2) are positive continuous w-periodic functions in R+=[0,∞),bi (i = 1,2) is nonnegative continuous w-periodic function in R+=[0,∞), w and T are positive constants. Ki,Lt ∈ C([-T,0], (01 88)) and Ki(s)ds = 1,ds - 1. i = 1,2. Some known results are improved and extended. 相似文献
15.
Essentially sharp bounds for small prime solutionsp
j
,q
i
of the following two different types of equations are obtained.
相似文献
16.
V. N. Chubarikov 《Mathematical Notes》1976,20(1):589-593
We obtain an estimate of the modulus of a complete multiple rational trigonometric sum: $$\left| {\sum {_{x_{1, \ldots ,} x_r = 1^{\exp \left( {{{2\pi if\left( {x_{1, \ldots ,} x_r } \right)} \mathord{\left/ {\vphantom {{2\pi if\left( {x_{1, \ldots ,} x_r } \right)} q}} \right. \kern-\nulldelimiterspace} q}} \right)} }^q } } \right| \ll q^{{{r - 1} \mathord{\left/ {\vphantom {{r - 1} {n + \varepsilon }}} \right. \kern-\nulldelimiterspace} {n + \varepsilon }}} ,$$ where $$\begin{gathered} f\left( {x_{1, \ldots ,} x_r } \right) = \sum {_{0 \leqslant t_1 , \ldots ,t_r \leqslant n^a t_1 , \ldots ,t_r x_1^{t_1 } \ldots x_r^{t_r } ,} } \hfill \\ a_{0, \ldots ,0} = 0,\left( {a_{0, \ldots ,0,1} , \ldots ,a_{n, \ldots ,n,} q} \right) = 1 \hfill \\ \end{gathered} $$ , and an estimate of the modulus of a multiple trigonometric integral. 相似文献
17.
Gerhard Larcher 《manuscripta mathematica》1997,94(1):501-529
We give some “rational analoga” to metric results in the classical theory of the diophantine approximation of zero by linear forms. That is: we study the behaviour of expressions of the form $$\begin{gathered} \lim _{m \to \infty } \frac{1}{{\left| {P_s (m)} \right|}}|\{ (x_1 , \ldots ,x_s ) \in P_s (m): \hfill \\ \parallel a_1 \frac{{x_1 }}{m} + \ldots + a_s \frac{{x_s }}{m}\parallel _m \geqslant \psi (a_1 , \ldots ,a_s ,m) \hfill \\ for all - \frac{m}{2}< a_1 , \ldots ,a_s \leqslant \frac{m}{2}, \hfill \\ with (a_1 , \ldots ,a_s ) \ne (0, \ldots ,0)\} |, \hfill \\ \end{gathered} $$ whereP s (m) is a certain subset of {1, …,m} s , ψ is a certain nonnegative function, and ‖ · ‖ m means the maximum of 1/m and the distance to the nearest integer. Some of the investigations are also motivated by problems in the theory of uniform distribution and of pseudo-random number generation. The results partly depend on the validity of the generalized Riemann hypothesis. 相似文献
18.
G. Sh. Guseinov 《Mathematical Notes》1978,23(5):391-398
The inverse problem about two-spectra for the equation
19.
§1 IntroductionAnvarovandLarinov[1]introducedthefollowingprey-predatorsystem:x(t)=x(t)[α-γy(t)-γ∫∞0K1(s)y(t-s)ds-∫∞0∫∞0R1(s,θ)y(t-s)y(t-θ)dθds],y(t)=y(t)[-β μx(t) μ∫∞0K2(s)x(t-s)ds ∫∞0∫∞0R2(s,θ)x(t-θ)x(t-s)dθds],(1)whereα,γ,βandμarepositiveconstants,Ki∈C([0,∞),(0,∞))andRi∈C([0,∞)×[0,∞),(0,∞)),i=1,2.Fortheecologicalsenseofsystem(1),wereferto[1,2]andrefer-encescitedtherein.Sincerealisticmodelsrequiretheinclusionoftheeffectofchangingen-vironment,itmot… 相似文献
20.
M. Farré 《Applied Mathematics and Optimization》1996,33(3):293-313
LetW be the Wiener process onT=[0, 1]2. Consider the stochastic integral equation $$\begin{gathered} X_\zeta = x_0 + \int_{R_\zeta } {a_1 (\zeta \prime )X(s\prime ,dt\prime )ds\prime + } \int_{R_\zeta } {a_2 (\zeta \prime )X(ds\prime ,t\prime )dt\prime } \hfill \\ + \int_{R_\zeta } {a_3 (X_{\zeta \prime , } \zeta \prime )W(ds\prime ,dt\prime ) + } \int_{R_\zeta } {a_4 (X_{\zeta \prime , } \zeta \prime )ds\prime ,dt\prime ,} \hfill \\ \end{gathered} $$ whereR ζ =(s, t) ∈ T, andx 0 ∈ ?. Under some assumptions on the coefficients ai, the existence and uniqueness of a solution for this stochastic integral equation is already known (see [6]). In this paper we present some sufficient conditions for the law ofX ζ to have a density. 相似文献
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