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101.
Ion Grosu Lo?c Toupet Gerard Plé Sorin Mager Eugen Mesaros Andreea Varga Elena Bogdan 《Monatshefte für Chemie / Chemical Monthly》2000,54(5):277-286
The synthesis and stereochemistry of new dibrominated spiro-1,3-dioxane derivatives are reported. Investigations by means
of NMR methods and single crystal X-ray diffraction for two compounds revealed the high regio- and diastereoselectivity of
the bromination reaction of some new spiro-1,3-dioxanes and the asymmetric induction of the chiral carbon atom located in
the spiro skeleton. 相似文献
102.
Andrei Popescu 《Mathematical Logic Quarterly》2004,50(3):265-280
The paper proposes a flexible way to build concepts within fuzzy logic and set theory. The framework is general enough to capture some important particular cases, with their own independent interpretations, like “antitone” or “isotone” concepts constructed from fuzzy binary relations, but also to allow the two universes (of objects and attributes) to be equipped each with its own truth structure. Perhaps the most important feature of our approach is that we do not commit ourselves to any kind of logical connector, covering thus the case of a possibly non‐commutative conjunction too. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
103.
The low excited states of the69As nucleus have been described in the framework of theSU(6) particle-quadrupole-phonon coupling model (PTQM). 相似文献
104.
V.I. Zoran M. Ganciu A.M. Pointu C.B. Collins I.-I. Popescu 《Hyperfine Interactions》1997,107(1-4):415-430
An inexpensive, tunable, filamentary X-ray generator, based on the bremsstrahlung of a pulsed, high-power-density electron
beam cruising along a dielectric fiber is presented. At small scale, it encodes some of the features of an X-ray machine for
triggering the energy stored in the long-lived 178Hfm2 nuclear isomer, in particular an optimum coupling to the active medium
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
105.
106.
We introduce pretty clean modules, extending the notion of clean modules by Dress, and show that pretty clean modules are sequentially Cohen–Macaulay. We also extend a theorem of Dress on shellable simplicial complexes to multicomplexes. 相似文献
107.
We find asymptotic expansions in the “string mass” μ for μ-deformed Γ-functions and Neumann coefficients characterizing the
three-string vertex in the light-cone gauge of the field theory of open superstrings on a maximally supersymmetric pp-wave
background.
Dedicated to the 80th birthday of Academician Anatolii Alekseevich Logunov
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 149, No. 3, pp. 381–385, December, 2006. 相似文献
108.
M. Yu. Novikov A. S. Sorin V. Yu. Tseitlin V. P. Shelest 《Theoretical and Mathematical Physics》1986,69(1):977-987
Conclusions Thus, we have shown that in QED3 systematic allowance for screening makes it possible to eliminate infrared divergences and in this respect advance further than in QCD4, in which the question of the mechanism of their elimination remains open. The comparative simplicity of the model also makes it possible to study systematically the more important question of the general structure of the series of skeleton perturbation theory and the excitation spectrum. We are currently working on this question.All-Union Scientific-Research Center for the Study of Surface and Vacuum Properties. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 69, No. 1, pp. 25–39, October, 1986. 相似文献
109.
The authors discuss the existence and uniqueness up to isometries of Enof immersions φ : Ω R~n→ E~n with prescribed metric tensor field(g ij) : Ω→ S~n, and discuss the continuity of the mapping(gij) →φ defined in this fashion with respect to various topologies. In particular, the case where the function spaces have little regularity is considered. How, in some cases, the continuity of the mapping(gij) →φ can be obtained by means of nonlinear Korn inequalities is shown. 相似文献
110.
Higher order elements were first design for linear problems where, in certain situations, they present advantages over the lower order elements. A method to efficiently extend their use to geometrical nonlinear problems as panel flutter and postbuckling behavior is presented. The chaotic and limit-cycle oscillations of an isotropic plate are obtained based on direct integration of the discretized equation of motion. The plate is modeled using the von Karman theory and the geometrical nonlinearities are separated in a nonlinear term of the first kind which manifests especially in the prebuckling and buckling regimes, and a nonlinear term of the second kind which is responsible for the postbuckling behavior. A fifth order, fully compatible element has been used to model thin plates while the inplane loads where introduced through a membrane element. The aerodynamics was modeled using the first order 'piston theory. The method introduces the concept of a deteriorated form of the second geometric matrix which is equivalent to neglecting higher order terms in the strain energy of the plate. This allows for a drastic reduction in the computational effort with no observable loss of accuracy. Well established results in the literature are used to validate the method. 相似文献