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71.
The difference absorption spectra of different grades of gasoline (A-76, AI-92, and AI-95) with octane numbers lying within 76–85 have been investigated experimentally in comparison with hydrocarbons: isooctane, benzene, and n-heptane. The spectra obtained contain absorption bands of the CH3, CH2, and CH groups and supposedly of the olefin double bond. The possibility of determining the octane number of an unknown grade of gasoline by using the absorption of a measured difference spectrum at one selected wavelength is shown. 相似文献
72.
We develop a notion of an n-fold monoidal category and show that it corresponds in a precise way to the notion of an n-fold loop space. Specifically, the group completion of the nerve of such a category is an n-fold loop space, and free n-fold monoidal categories give rise to a finite simplicial operad of the same homotopy type as the classical little cubes operad used to parametrize the higher H-space structure of an n-fold loop space. We also show directly that this operad has the same homotopy type as the n-th Smith filtration of the Barratt-Eccles operad and the n-th filtration of Berger's complete graph operad. Moreover, this operad contains an equivalent preoperad which gives rise to Milgram's small model for when n=2 and is very closely related to Milgram's model of for n>2. 相似文献
73.
Samia Beghdadi-Sakrani 《Journal of Theoretical Probability》2003,16(4):789-812
We consider the stochastic differential equation: dX
t
=(|X
t
|)dB
t
, where B is a Brownian motion and is a non-Hölder Borel function. A sufficient condition of pathwise uniqueness is given. 相似文献
74.
Giulio?CodognatoEmail author Sayantan?GhosalEmail author 《International Journal of Game Theory》2003,31(4):493-498
In this paper, we generalize the exitence result for pure strategy Nash equilibria in anonymous nonatomic games. By working directly on integrals of pure strategies, we also generalize, for the same class of games, the existence result for undominated pure strategy Nash equilibria even though, in general, the set of pure strategy Nash equilibria may fail to be weakly compact.
Received August 2001 相似文献
75.
Ralph Kummetz 《Applied Categorical Structures》2003,11(1):3-25
This paper investigates function spaces of structures consisting of a partially ordered set together with some directed family of projections.More precisely, given a fixed directed index set (I,), we consider triples (D,,(p
i
)
iI
) with (D,) a poset and (p
i
)
iI
a monotone net of projections of D. We call them (I,)-pop's (posets with projections). Our main purpose is to study structure preserving maps between (I,)-pop's. Such homomorphisms respect both order and projections.Any (I,)-pop is known to induce a uniformity and thus a topology. The set of all homomorphisms between two (I,)-pop's turns out to form an (I,)-pop itself. We show that its uniformity is the uniformity of uniform convergence. This enables us to prove that properties such as completeness and compactness transfer to function pop's.Concerning categorical properties of (I,)-pop's, we will see that we are in a lucky situation from a computer scientist's point of view: we obtain Cartesian closed categories. Moreover, by a D
-construction we get (I,)-pop's that are isomorphic to their own exponent. This yields new models for the untyped -calculus. 相似文献
76.
Let A be a finite-dimensional algebra over arbitrary base field k. We prove: if the unbounded derived module category D-(Mod-A) admits symmetric recollement relative to unbounded derived module categories of two finite-dimensional k-algebras B and C:D- (Mod - B) D-(Mod - A) D-(Mod - C),then the unbounded derived module category D-(Mod - T(A)) admits symmetric recollement relative to the unbounded derived module categories of T(B) and T(C):D-(Mod - T(B)) D-(Mod - T(A)) D-(Mod -T(C)). 相似文献
77.
On a Lift of an Individual Stable Equivalence to a Standard Derived Equivalence for Representation-Finite Self-injective Algebras 总被引:1,自引:0,他引:1
Hideto Asashiba 《Algebras and Representation Theory》2003,6(4):427-447
We shall show that every stable equivalence (functor) between representation-finite self-injective algebras not of type (D
3m
,s/3,1) with m2, 3s lifts to a standard derived equivalence. This implies that all stable equivalences between these algebras are of Morita type. 相似文献
78.
Michel Hébert 《Applied Categorical Structures》2001,9(6):595-623
We give concrete versions of the characterizations of locally -presentable (resp. -generated) categories as categories of models of (resp. weakly) -ary limit-theories and of (resp. weakly) -ary essentially algebraic theories. By concrete we mean that starting with a category of -structures, the theories obtained are extensions of the original ones, and the equivalences of categories are concrete isomorphisms. -presentable and -generated objects are also investigated from this viewpoint. 相似文献
79.
Piotr Zakrzewski 《Proceedings of the American Mathematical Society》2001,129(6):1793-1798
We study category counterparts of the notion of a universal measure zero set of reals.
We say that a set is universally meager if every Borel isomorphic image of is meager in . We give various equivalent definitions emphasizing analogies with the universally null sets of reals.
In particular, two problems emerging from an earlier work of Grzegorek are solved.
80.
We prove that (a) in a reflexive space, for any linearly bounded but unbounded closed convex subset the nonsupport functionals are a dense G
subset of the polar set, and (b) any nonsemicoercive proper convex lsc [weak*-lsc] function in a [dual] Banach space has a generic [dense G
] set of L
-perturbations which do not attain their infimum. We also characterize the proper convex functions that have inf-nonattaining L
-perturbations. This results also in a criterion for reflexivity. 相似文献