ISSN:0025-5793    

DOI:10.1112/S0025579300007324

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractLetXbe a separable and metrizable space containing uncountably many pairwise disjoint copies of the compactumK. We discuss the question whetherXmust containK× 2ω.

ISSN:0025-5793    

DOI:10.1112/S0025579300007336

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractIt is proved thatC(K) has no equivalent uniformly Gâteaux differentiable norm (UGD) whenK‐is an uncountable separable scattered com¬pact space. This result is applied to obtain an example of scattered compactKsuch thatK′″ = ∅ andC(K) has no UGD renorming.

ISSN:0025-5793    

DOI:10.1112/S0025579300007348

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

ISSN:0025-5793    

DOI:10.1112/S002557930000735X

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractWe prove a characterization of functions inB1/4(K)\C(K), whereKis a compact metric space in terms ofc0‐spreading models, answering a Problem of R. Haydon, E. Odell and H. Rosenthal. Beginning withB1/4(K) we define a decreasing family (Vξ(K),║ · ║ξ)1≤ξξ for everyF∈Vξ(K). Also we classify the separable Banach spaces by defining thec0‐SM‐index which measures the degree to which they have sequences with extending spreading models equivalent to the usual basis ofc0. We give examples of Baire‐1 functions and reflexive spaces with arbitrary large indices.

ISSN:0025-5793    

DOI:10.1112/S0025579300007361

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

ISSN:0025-5793    

DOI:10.1112/S0025579300007373

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractThe impaction on symmetrical obstacles placed in uniform streams of aerosols is investigated. The governing equations of motion are nonlinear differential equations involving a parameter called the Stokes number. The study differentiates between the critical value of the Stokes number on the centre‐line,kcr, below which no particles reach the stagnation point in finite time, and the critical value of the Stokes number on the obstacle,Kcr, below which no particles may be deposited on the obstacle in finite time. Based on the properties of the centre‐line fluid velocity of the potential and viscous flows past a variety of symmetrically shaped obstacles, upper and lower bounds ofKcrandKcrare established. Furthermore, using a numerical procedure for solving nonlinear differential equations with unknown parameters the critical values ofKcrandKcrare obtained.

ISSN:0025-5793    

DOI:10.1112/S0025579300007385

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractIn this paper, we consider an extended model of a coupled nonlinear reaction‐diffusion equations with Neumann‐Neumann boundary conditions. We obtain upper linear growth bound for one of the components. We also find the corresponding bound for the case of Dirichlet‐Dirichlet boundary conditions.

ISSN:0025-5793    

DOI:10.1112/S0025579300007397

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractWe establish a generalization of the Cesari‐Kannan existence result for problems of the typeLx=N(x),x∈XwhereXis a separable Hilbert functional space,Lis a selfadjoint linear differential operator with nontrivial finite dimensional kernel andN:X→Xis a bounded continuous nonlinear operator. This generalization leads to new results when the dimension of the kernel ofLis greater than one. Applications to systems of second order ordinary differential equations are given.

ISSN:0025-5793    

DOI:10.1112/S0025579300007403

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY

摘要:

AbstractOur aim in this paper is to establish new comparison principles. The equation(*)(r(t)u′(t))′+p(t)|u(g(t))|α sgn u(g(t))=0is compared with the equation(l(t)y′(t))′+z(t)|y(w(t))|β sgn y(w(t))=0.The equations considered can be in canonical or noncanonical forms.

ISSN:0025-5793    

DOI:10.1112/S0025579300007415

出版商:London Mathematical Society    

年代:1994

数据来源: WILEY