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731.
We prove existence and regularity results for a general inequality including fixed point problems, variational and quasi variational inequalities. Examples of such problems are considered.  相似文献   
732.
We consider functionals of the form: If(u) = ∝Tf[t, u(t)]μ(dt), which are defined on spaces Lp(T, Rk), and we study for these functionals the properties of a convergence for which the conjugacy If → If1 is a continuous operator.  相似文献   
733.
734.
Let F be any family of subsets of a finite set E and let n be an integer, n<|F|. Under what condition does the knowledge of cardinals of m-intersections in F, for all mn, univocally determine the cardinal of any intersection in F, and what is the minimal condition? We give a complete answer to that. For any n, this determination property is satisfied by n if and only if |E|<2n, without further condition on F.  相似文献   
735.
[reaction: see text] Diastereoselective additions of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines are described. alpha,alpha'-Diaminophosphinic and alpha-amino-alpha'-hydroxyphosphinic derivatives were obtained with de's ranging from 24 to 90%.  相似文献   
736.
Synthesis of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes via either intramolecular transesterification, using potassium tert-butylate as catalytic agent, or phosphinic acid esterification, is described for the first time.  相似文献   
737.
Aggarwal VK  Vasse JL 《Organic letters》2003,5(21):3987-3990
[reaction: see text] Sulfur ylide methodology has been used to construct the Taxol side chain with a high degree of enantioselectivity via a trans-aziridine followed by stereospecific rearrangement of the trans-benzoylaziridine into a trans-oxazoline.  相似文献   
738.
We present an exact field theoretical representation of the statistical mechanics of classical hard-core Coulomb systems. This approach generalizes the usual sine-Gordon theory valid for point-like charges or lattice systems to continuous Coulomb fluids with additional short-range interactions. This formalism is applied to derive the equation of state of the restricted primitive model of electrolytes in the low fugacity regime up to order ρ5/2 (ρ number density). We recover the results obtained by Haga by means of Mayer graphs expansions.  相似文献   
739.
This Letter describes the synthesis of two racemic analogues of unnatural 3′-deoxy and 2′-deoxy sugars, where a phosphorus atom replaces the carbon atom in the 2′- or 3′-position. Two methods of four- and 5-steps were developed affording these new unnatural sugar analogues.  相似文献   
740.
A convenient measure of a map or flow’s chaotic action is the topological entropy. In many cases, the entropy has a homological origin: it is forced by the topology of the space. For example, in simple toral maps, the topological entropy is exactly equal to the growth induced by the map on the fundamental group of the torus. However, in many situations the numerically computed topological entropy is greater than the bound implied by this action. We associate this gap between the bound and the true entropy with ‘secondary folding’: material lines undergo folding which is not homologically forced. We examine this phenomenon both for physical rod stirring devices and toral linked twist maps, and show rigorously that for the latter secondary folds occur.  相似文献   
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