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141.
142.
《Annals of Pure and Applied Logic》2022,173(10):103108
Probabilistic team semantics is a framework for logical analysis of probabilistic dependencies. Our focus is on the axiomatizability, complexity, and expressivity of probabilistic inclusion logic and its extensions. We identify a natural fragment of existential second-order logic with additive real arithmetic that captures exactly the expressivity of probabilistic inclusion logic. We furthermore relate these formalisms to linear programming, and doing so obtain PTIME data complexity for the logics. Moreover, on finite structures, we show that the full existential second-order logic with additive real arithmetic can only express NP properties. Lastly, we present a sound and complete axiomatization for probabilistic inclusion logic at the atomic level. 相似文献
143.
《Annals of Pure and Applied Logic》2022,173(1):102991
We generalize the lexicographic product of first-order structures by presenting a framework for constructions which, in a sense, mimic iterating the lexicographic product infinitely and not necessarily countably many times. We then define dense substructures in infinite products and show that any countable product of countable transitive homogeneous structures has a unique countable dense substructure, up to isomorphism. Furthermore, this dense substructure is transitive, homogeneous and elementarily embeds into the product. This result is then utilized to construct a rigid elementarily indivisible structure. 相似文献
144.
《Indagationes Mathematicae》2022,33(3):598-624
We construct left invariant special Kähler structures on the cotangent bundle of a flat pseudo-Riemannian Lie group. We introduce the twisted cartesian product of two special Kähler Lie algebras according to two linear representations by infinitesimal Kähler transformations. We also exhibit a double extension process of a special Kähler Lie algebra which allows us to get all simply connected special Kähler Lie groups with bi-invariant symplectic connections. All Lie groups constructed by performing this double extension process can be identified with a subgroup of symplectic (or Kähler) affine transformations of its Lie algebra containing a nontrivial 1-parameter subgroup formed by central translations. We show a characterization of left invariant flat special Kähler structures using étale Kähler affine representations, exhibit some immediate consequences of the constructions mentioned above, and give several non-trivial examples. 相似文献
145.
A toric origami manifold, introduced by Cannas da Silva, Guillemin and Pires,
is a generalization of a toric symplectic manifold. For a toric symplectic manifold, its
equivariant Chern classes can be described in terms of the corresponding Delzant polytope
and the stabilization of its tangent bundle splits as a direct sum of complex line bundles.
But in general a toric origami manifold is not simply connected, so the algebraic topology
of a toric origami manifold is more difficult than a toric symplectic manifold. In this paper
they give an explicit formula of the equivariant Chern classes of an oriented toric origami
manifold in terms of the corresponding origami template. Furthermore, they prove the
stabilization of the tangent bundle of an oriented toric origami manifold also splits as a
direct sum of complex line bundles. 相似文献
146.
V. G. Pleshakov V. M. Akimov E. Huipe Nava S. V. Lindeman Yu. T. Struchkov K. D. Ambacheu A. G. Dudareva M. A. Ryashentseva V. P. Zvolinsky N. S. Prostakov 《Russian Chemical Bulletin》1995,44(4):682-688
Based on thermogravimetric characteristics first obtained for the model 6H-indeno [1,2-b]quinoline, the scheme of thermal conversions of this compound in the temperature range 20–700 °C has been proposed, and the limit of its thermal stability (300 °C) has been determined. This temperature is recommended as the optimum for synthesizing fused benzoaza(diaza)fluorenes. Based on the results of X-ray structural analysis, the molecules of the studied indenoquinoline form centrosymmetric pairs, which are arranged in (110) layers. The molecules are orientationally disordered. The observed self-association of these molecules is similar to the - association of fused heterocyclic systems with-excessive and
****- deficient fragments. It has been suggested that interferon-inducing and antitumor compounds with an annelated indenyl fragment have a common mechanism of action according to the intercalation model of stacking structures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 703–709, April, 1995. 相似文献
147.
Copolymerisation of methyl methacrylate with nine novel monomer compounds, triazinyl benzanthrone dyes, triazinyl benzotriazole stabilisers and their combined structures, was investigated. Chemical bonding of the compounds in the polymers obtained was confirmed spectrophotometrically. The quantity of the chemically bonded monomer compounds was determined to be over 50%, providing a colour and a fluorescence stable to solvents. Their influence on the rate of the copolymerisation was studied. It was found that the compounds under study did not significantly affect the rate of copolymerisation. A stabilizing effect towards photo-degradation of PMMA was achieved at 0.1 wt.% initial concentration of the compounds, which made them suitable for “one-step” colouration and stabilisation of PMMA. 相似文献
148.
Michael MuehlhoferThomas Strassner Eberhardt HerdtweckWolfgang A Herrmann 《Journal of organometallic chemistry》2002,660(2):121-126
Novel bridged platinum(II) biscarbene complexes are reported: 1,1′-dimethyl-3,3′-methylene-4-diimidazolin-2,2′-diylidene platinum(II) (3) and 1,1′-dimethyl-3,3′-ethylene-4-diimidazolin-2,2′-diylidene platinum(II) complexes 4 are directly accessible in high yields starting from platinum halides. The one-pot synthesis obviates the need for multi-step reactions via metal precursors or free carbenes. An X-ray crystal structure of 1,1′-dimethyl-3,3′-methylene-4-diimidazolin-2,2′-diylidene platinum(II) dibromide (3b) confirmed the structural similarity to the known corresponding palladium complexes. Since free 1,1′-di-R-3,3′-methylene-4-diimidazolin-2,2′-diylidenes are only available in low yields this synthetic route provides an easy access to the corresponding carbene complexes. 相似文献
149.
Maria?Victoria Roux Paul?J.?Smith Joel?F.?LiebmanEmail author 《Structural chemistry》2005,16(1):73-75
Despite their seeming simplicity, substituted guanidines have not particularly caught the attention of the thermochemical community. The current paper compares the enthalpy of formation of solid substituted guanidines with correspondingly substituted benzenes, also as solids. 相似文献
150.
煤的孔结构特征对水煤浆性质的影响 总被引:7,自引:3,他引:7
本文选用17种不同变质程度的中国煤,详细研究了煤孔结构特征对煤浆性质的影响。发现煤孔体积通过影响煤在分散体系中的吸水性,从而影响煤之成浆性。但由于不同变质程度煤表面亲水性的显著差异,煤孔体积在影响煤成浆性的能力方面差别很大,这使得煤吸水性和浆体最高煤浓度与煤孔体积并不存在直接的相关性,而是取决于煤孔体积V和以煤-水接触角(θ)的余弦值表示的煤表面亲水性因子的乘积,即煤之有效孔体积:V×cos(θ/ 相似文献