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121.
John Harding 《Order》1991,8(1):93-103
The only known example of an orthomodular lattice (abbreviated: OML) whose MacNeille completion is not an OML has been noted independently by several authors, see Adams [1], and is based on a theorem of Ameniya and Araki [2]. This theorem states that for an inner product space V, if we consider the ortholattice ?(V,⊥) = {A \( \subseteq \) V: A = A ⊥⊥} where A ⊥ is the set of elements orthogonal to A, then ?(V,⊥) is an OML if and only if V is complete. Taking the orthomodular lattice L of finite or confinite dimensional subspaces of an incomplete inner product space V, the ortholattice ?(V,⊥) is a MacNeille completion of L which is not orthomodular. This does not answer the longstanding question Can every OML be embedded into a complete OML? as L can be embedded into the complete OML ?(V,⊥), where V is the completion of the inner product space V. Although the power of the Ameniya-Araki theorem makes the preceding example elegant to present, the ability to picture the situation is lost. In this paper, I present a simpler method to construct OMLs whose Macneille completions are not orthomodular. No use is made of the Ameniya-Araki theorem. Instead, this method is based on a construction introduced by Kalmbach [7] in which the Boolean algebras generated by the chains of a lattice are glued together to form an OML. A simple method to complete these OMLs is also given. The final section of this paper briefly covers some elementary properties of the Kalmbach construction. I have included this section because I feel that this construction may be quite useful for many purposes and virtually no literature has been written on it. 相似文献
122.
This paper reviews the theory of search. The main viewpoint is statistical but considerable space is spent on connections with other fields such as logic and optimisation. Three primitive ideas dominate: consistency, entropy, and Bayes' methods. The theory of screening provides one of the central examples and there is a section on nonsequential random search deriving from the work of Renyi. The game of Bulls and Cows provides a motivating example for both sequential and nonsequential algorithms. 相似文献
123.
Differential calculus on quantized simple lie groups 总被引:1,自引:0,他引:1
Branislav Jurčo 《Letters in Mathematical Physics》1991,22(3):177-186
Differential calculi, generalizations of Woronowicz's four-dimensional calculus on SU
q
(2), are introduced for quantized classical simple Lie groups in a constructive way. For this purpose, the approach of Faddeev and his collaborators to quantum groups was used. An equivalence of Woronowicz's enveloping algebra generated by the dual space to the left-invariant differential forms and the corresponding quantized universal enveloping algebra, is obtained for our differential calculi. Real forms for q are also discussed. 相似文献
124.
Janusz Matkowski 《Aequationes Mathematicae》1992,43(2-3):219-224
Summary In the present note we prove that every functionf: (0, ) [0, ) satisfying the inequalityaf(s) + bf(t) f(as + bt), s, t > 0, for somea andb such that 0 <a < 1 <a + b must be of the formf(t) = f(1)t, (t > 0). This improves our recent result in [2], where the inequality is assumed to hold for alls, t 0, and gives a positive answer to the question raised there.An analogue for functions of several real variables of the above result characterizes concave functions. Conjugate functions and some relations to Hölder's and Minkowski's inequalities are mentioned. 相似文献
125.
Bent Fuglede 《Potential Analysis》1992,1(4):355-371
The first property is a refinement of earlier results of Ch. de la Vallée Poussin, M. Brelot, and A. F. Grishin. Let w=u–v with u, v superharmonic on a suitable harmonic space (for example an open subset of R
n
), and let [w]=[u]–[v] denote the associated Riesz charge. If w0, and if E denotes the set of those points of at which the lim inf of w in thefine topology is 0, then the restriction of [w] to E is 0. Another property states that, if e denotes a polar subset of such that the fine lim inf of |w| at each point of e is finite, then the restriction of [w] to e is 0. 相似文献
126.
We study topological conditions that must be satisfied by a compactC ∞ Levi-flat hypersurface in a two-dimensional complex manifold, as well as related questions about the holonomy of Levi-flat hypersurfaces. As a consequence of our work, we show that no two-dimensional complex manifold admits a subdomain Ω with compact nonemptyC ∞ boundary such that Ω ? ?2. 相似文献
127.
Chi-Keung Cheung 《Journal of Geometric Analysis》1992,2(2):105-119
In this paper we considered curvature conditions on a Kähler-Einstein surface of general type. In particular we showed that it has negative holomorphic sectional curvature if theL 2-norm of (3C 2 ?C 1 2 )/C 1 2 is sufficiently small, whereC 1 andC 2 are the first and second Chern classes of the surfaces. This generalizes a result of Yau on the uniformization of Kähler-Einstein surfaces of general type and with 3C 2 ?C 1 2 = 0. Also in the process, we obtain a necessary condition in terms of an inequality between Chern numbers for a Kähler-Einstein metric to have negative holomorphic sectional curvature. 相似文献
128.
Š. Porubský 《Periodica Mathematica Hungarica》1982,13(1):9-14
A necessary and sufficient condition for the group of isomorphisms involved in a factorization of a complete graph into isomorphic factors is established. 相似文献
129.
J. A. Navio M. Macias A. Justo C. Real 《Journal of Thermal Analysis and Calorimetry》1992,38(4):673-682
The thermal decomposition of sodium nitrite or nitrate pre-adsorbed upon TiO2 surfaces has been investigated by employing several techniques as infrared spectroscopy (IR) and temperature programmed desorption in conjunction with mass spectrometry analysis (TPD-MS) to study the features observed during these thermal decompositions. Differential thermal analysis (DTA) in combination with X-ray diffraction analysis (XRD) were used to investigate the possibility of a solid state chemical reaction between the solid products originated from the thermal decomposition of the pre-adsorbed species and the TiO2. On the basis of our results, various characteristic features of these thermal decomposition reactions will be discussed.This work was supported by JUNTA DE ANDALUCIA (financial support for research groups/1990). 相似文献
130.
A. A. Bezrukova V. S. Khandkarova P. V. Petrovskii A. Z. Rubezhov Ya. S. Vygodskii K. P. Butin T. V. Magdesieva G. A. Pirogova 《Russian Chemical Bulletin》1995,44(5):941-945
Binuclear RhIII and RuII complexes of the [M1-CN-M2]+BF
4
–
(M1 and/or M2 are (5-Cp)(3-C3H5)Rh and (6-C6H6)(3-C3H5)Ru) type, heteronuclear organometallic compound (5-Cp)(3-C3H5)RhCNPd(3-C3H5)Cl, and mononuclear RhIII and RuII complexes [(3-C3H5)LM(MeCN)]+
BF4
–
(M = Rh, L = 5-Cp; M = Ru, L = 6-C6H6) were synthesized. An electrochemical study of these compounds in solutions demonstrates that the bond between the bridged CN ligand and the metal atoms is rather strong, and there is no dissociation into mononuclear fragments in solutions. The kinetics of the reaction of [(5-Cp)(3-C3H5)Rh(MeCN)]+
BF4
–
with halide ions was studied by electrochemical methods. The ligand exchange proceeds by a bimolecular dissociative-exchange mechanism.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 968–973, May, 1995. 相似文献