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1.
A finite support product of clones of Jensen's minimal singleton forcing is used to define a model in which any non-empty analytically definable set of reals contains an analytically definable real (the full basis theorem), but there is no analytically definable wellordering of the reals. 相似文献
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Dmitry S. Zimnitsky Tatiana L. Yurkshtovich Pavel M. Bychkovsky 《Journal of polymer science. Part A, Polymer chemistry》2004,42(19):4785-4791
Samples of oxidized cellulose (OC) with various carboxyl contents and degrees of crystallinity were obtained by the oxidation of native and mercerized cellulose with a solution of nitrogen(IV) oxide in CCl4. A detailed characterization of these OC samples was performed. The effect of oxidation conditions (concentration of N2O4 in the solution and oxidation time) and starting cellulose material on OC characteristics (carboxyl, carbonyl and nitrogen content, degree of crystallinity and polymerization, surface area and swelling, and acidic properties) was investigated. Reactivity in the oxidation process was higher in mercerized cellulose than in native cellulose. The action of dilute solutions (10–15%) of N2O4 did not affect the degree of crystallinity of cellulose samples. Under these conditions, the oxidation took place mainly in amorphous regions and on the surface of crystallites. Oxidation in a concentrated (40%) N2O4 solution led to the destruction of crystallites, which increased the surface area and swelling of cellulose in water. The surface area and the swelling of OC samples increased with a decrease in the index of crystallinity. The acidic properties of OC were shown to increase with an increase of swelling in water. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4785–4791, 2004 相似文献
5.
Dmitry Panchenko 《Random Structures and Algorithms》2004,24(1):65-74
Using Talagrand's concentration inequality on the discrete cube {0, 1}m we show that given a real‐valued function Z(x) on {0, 1}m that satisfies certain monotonicity conditions one can control the deviations of Z(x) above its median by a local Lipschitz norm of Z at the point x. As one application, we obtain a deviation inequality for the number of k‐cycles in a random graph. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2004 相似文献
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V. A. Lyubetsky 《Algebra and Logic》1997,36(3):169-181
A set theory ZFI′ which does not employ the Law of the Excluded Middle φ ∀ ⊥ φ, for all φ, retians the stock of expressive
capacities of the classical set theory ZF, on the one hand, and has many of the features of an effective theory on the other.
In the article, a broad class of formulas σ is constructed for which ZF ⊥ σ implies ZFI′ ⊥ σ. This result provides a generalization
of Friedman's theorem on AE-arithmetic formulas. Besides, we prove transfer theorems of classical logic for the case of rings;
in particular, Hilbert's theorem on zeros and Artin's theorem on ordered fields are extended to the case of regular f-rings,
and we bring in appropriate upper bounds for them.
Supported by RFFR grant No. 93-012-1027.
Translated fromAlgebra i Logika, Vol. 36, No. 3, pp. 282–303, May–June, 1997. 相似文献
8.
Alexander N Shivanyuk Dmitry M Rudkevich David N Reinhoudt 《Tetrahedron letters》1996,37(52):9341-9344
An assembly of cation receptor 1 and anion receptor 2 via the hydrogen bonding melamine-barbiturate structural motif complexes sodium thiocyanate, sodium iodide, and sodium azide in apolar solvents. 相似文献
9.
The dependencies of the effective Hall properties on a scale, obtained by means of an iterative averaging method, manifest their fractal character. The influence of an intensity of the Hall effect on the fractal character of the Hall properties was considered. Scale ranges and dimensional characteristics of the effective Hall properties behavior were calculated and discussed. 相似文献
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Dmitry Dolgopyat 《Transactions of the American Mathematical Society》2004,356(4):1637-1689
We consider a large class of partially hyperbolic systems containing, among others, affine maps, frame flows on negatively curved manifolds, and mostly contracting diffeomorphisms. If the rate of mixing is sufficiently high, the system satisfies many classical limit theorems of probability theory.