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101.
102.
In this paper we investigate Stäckel transforms between different classes of parameter‐dependent Stäckel separable systems of the same dimension. We show that the set of all Stäckel systems of the same dimension splits to equivalence classes so that all members within the same class can be connected by a single Stäckel transform. We also give an explicit formula relating solutions of two Stäckel‐related systems. These results show in particular that any two geodesic Stäckel systems are Stäckel equivalent in the sense that it is possible to transform one into another by a single Stäckel transform. We also simplify proofs of some known statements about multiparameter Stäckel transform. 相似文献
103.
The first attempt of finding of optimal shape for bars in presence of body forces with respect to mixed creep rupture is made. For given volume of the bar, distribution of initial cross-section, ensuring the longest life-time to mixed rupture is sought. The finite strain theory and physical law in form of Norton's law generalized for true stresses and logarithmic strains are applied. Using the method of parametric optimization, the best of linear and quadratic functions describing the initial shape of the bar are found. The shape of initial strength is corrected in a way leading to longer life-time. Results of both approaches are compared. 相似文献
104.
105.
The significance of the electron–phonon interaction for optically stimulated luminescence (OSL) process in quartz is demonstrated. OSL variation with temperature has been investigated for four samples of natural quartz. Changes of the OSL decay rate have been observed for all components of the OSL signal. The scale and tendency of these changes are comparable with outcomes of computer simulations carried out for the model composed of two deep electron traps, one shallow trap and one recombination centre, taking into account the electron–phonon interactions. 相似文献
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107.
Monika Karpierz Jan Suchanicz Krzysztof Konieczny Dorota Sitko Pascal Marchet Urszula Lewczuk 《Phase Transitions》2015,88(7):662-667
The 0.5K0.5Bi0.5TiO3–0.5PbTiO3 ceramics were prepared by following a standard solid-state method. The Raman, thermal and dielectric properties of these ceramics were investigated. The X-ray measurements showed that samples have single perovskite-type structure with tetragonal symmetry. Dielectric study revealed that the dielectric behaviour of the investigated ceramics is rather of normal ferroelectrics with large thermal hysteresis. The transition temperature observed by means of differential scanning calorimetry measurements is in good agreement with that obtained from dielectric study. 相似文献
108.
Maciej Makowski Krzysztof Pawełczak Paweł Kafarski Jolanta M. Dzik Barbara Gołos Małgorzata Balinska 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1639-1651
The synthesis of six analogues of the potent thymidylate synthase (TS) inhibitor N -[4-[ N -[(3,4-dihydro-2-methyl-4-oxo-6-quinazolinoyl)-methyl]- N -prop-2-ynylamino]benzoyl]- L -glutamic acid 2 is described in which the glutamic acid residue has been replaced by DL -aminophosphonic acids. New antifolates were tested as inhibitors of TS isolated from mouse L1210 leukemic cells as well as inhibitors of growth mouse leukemic L5178Y cells. In general these modifications result in compounds that are considerably less potent than 2 as TS inhibitors with K i 's 0.17-1.10 w M. Very poor solubility in water limited their proper assay of growth cells inhibition. 相似文献
109.
Krzysztof Matyjaszewski 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1785-1801
Abstract Mechanistic and synthetic aspects of atom transfer radical polymerization (ATRP) are reviewed. This controlled/“living” system polymerizes many monomers including styrenes, (meth)acrylates, acrylonitrile and dienes. The halogen end groups can be converted to other functional groups such as amines and azides. In addition to producing well-defined linear homopolymers, statistical copolymers, block copolymers, and gradient copolymers, ATRP can be used to synthesize graft and hyperbranched copolymers through copolymerization with functionalized monomers. Selection of appropriate conditions for ATRP depends on targeted molecular weight and degree of polymer chain end-functionality and includes considering the monomer(s) to be polymerized, initiator structure/reactivity, amount of catalyst/deactivator used, halogen end-group used, and temperature. 相似文献
110.