1,730,274 research outputs found
𝑏−Algebras
No full textBu tezde, 𝑏−cebiri kavramını vererek bazı özelliklerini inceledik. Gelfand-Mazur teoreminin bir versiyonunu 𝑏−cebirlerinde şu şekilde elde ettik; 𝐴 birimli Arşimedyan düzgün tam 𝑏−cebiri ve 𝐴 da pozitif her eleman terse sahip ise 𝐴,ℝ'ye Riesz ve cebir izomorfiktir. 𝐴 Arşimedyan 𝑏−cebiri iken sıra sürekli biduali (𝐴~)𝑛~ in Arens çarpımı ile 𝑏−cebiri olduğunu, ek olarak 𝐴 pozitif kare özelliğine sahip Arşimedyan 𝑏−cebiri ise 𝐴~~ sıra bidualinin 𝑏−cebiri olduğunu gösterdik. Daha sonra 𝐸~ nın (𝐴~)𝑛~ üzerindeki 𝑓modül yapısını göz önüne alarak bu yapının belirlediği 𝜂∶ (𝐴~)𝑛~→𝑂𝑟𝑡ℎ(𝐸~) Arens homomorfizminin özellikleri üzerine çalıştık. Bunun sonucunda 𝐸 nin sıra idealleri ile 𝐴-altmodülleri arasındaki ilişkiyi gerekli ve yeterli koşul olarak verdik.In this thesis, we have investigated some new properties by giving the concept of 𝑏−algebras. We have obtained a version of the Gelfand-Mazur theorem in 𝑏−algebras which 𝐴 is Riesz and algebraical isomorphic with the reals whenever 𝐴 is a Archimedian 𝑏−algebra with unit element 𝑒>0 and such that every positive element has an inverse. Moreover, we show that the order continuous bidual (𝐴~)𝑛~ of an Archimedian 𝑏−algebra 𝐴 is a 𝑏−algebra with respect to the Arens multiplication. Furthermore, if the 𝑏−algebra 𝐴 has positive squares, then the order bidual 𝐴~~ is again a 𝑏−algebra. Then, we have worked on the properties of 𝜂:(𝐴~)𝑛~→𝑂𝑟𝑡ℎ(𝐸~) Arens homomorfizm determined by this structure, taking into account the 𝑓modul of 𝐸~ on (𝐴~)𝑛~. As a result, we have given the relationship between the order ideals of 𝐸 and A-submodules of 𝐸 as a necessary and sufficient condition
Sternheimer quadrupole shielding-antishielding function for F<SUP>−</SUP>, Cl<SUP>−</SUP>, Br<SUP>−</SUP> and I<SUP>−</SUP> in ionic solids
No full textIt is shown for the first time that the Sternheimer correction associated with the overlap contribution to the electric field gradient in ionic crystals can be assigned the constant values of 0.4, −0.8, −5.7 and −16.4 for F−, Cl−, Br− and I− respectively
Density functional calculations of the ionic radii of Be<SUP>−</SUP>, Mg<SUP>−</SUP>, Ca<SUP>−</SUP>, Sr<SUP>−</SUP>, Ba<SUP>−</SUP> and some metastable mononegative ions
No full textUsing the criterion that for the negative monoatomic ions, the location of the minimum in the electrostatic potential V(r) represents the ionic radius rm, the latter have been calculated for the negative ions H− (2s2 1S), H− (3s2 1S), H− (1s↓12s↓12p↓1 4P), Li− (1s↓12s↓12p↓2 5P), C− (2p↓22p↓1 2D), N− (2p↓22p↓21S), Be− (2p↓1 2P), Mg− (3p↓1 2P), Ca− (4p↓1 2P), Sr− (5p↓1 2P), and Ba− (6p↓1 2P), respectively. Quasi-relativistic self-interaction-corrected local-spin-density (SIC-LSD) functional with correlation energy has been used to calculated V(r) for all the ions
Ω<SUP>−</SUP> decay modes
No full textAn attempt is made to relate certain decay modes of the Ω− particle, by using the now well-known algebra of current components and the PCAC hypothesis. For the two pionic modes Ω− → Ξ− + π0 and Ω− → Ξ0 + π− one obtains the ΔI=1/2 rule, and we point out the differences between these cases and the theories of frcase1/2+ hyperon decays studied by others [1,2]. Although the experimental data concerning the Ω− are extremely slender, there is at least one event for each of the above modes, and the observed lifetimes are in fine agreement with the prediction. Using a similar procedure, the mode Ω− → Ξ0 + π0 + e− + V̅ is also related to Ω− → Ξ0 + e− + V̅. These modes, although not observed so far, are allowed energetically with sufficient phase space left for the products
Quadrupole polarizabilities of F<SUP>−</SUP>, Cl<SUP>−</SUP>, and Br<SUP>−</SUP> using ≡a theory
No full textQuadrupole polarizabilities αq have been calculated using ≡a wave functions and the Sternheimer charge-perturbed differential equation procedure for F−, Cl−, and Br−, respectively. It is shown that self-interaction correction with the proper choice of the exchange parameter, aKLI (KLI is Kulback-Leibler information measure), the calculated αq values are close to the corresponding Hartree-Fock estimates
Stabilization of wurtzite Sc0.4Al0.6N in pseudomorphic epitaxial ScxAl1−xN/InyAl1−yN superlattices
No full textS.101-110Pseudomorphic stabilization in wurtzite ScxAl1−xN/AlN and ScxAl1−xN/InyAl1−yN superlattices (x = 0.2, 0.3, and 0.4; y = 0.2-0.72), grown by reactive magnetron sputter epitaxy was investigated. X-ray diffraction and transmission electron microscopy show that in ScxAl1−xN/AlN superlattices the compressive biaxial stresses due to positive lattice mismatch in Sc0.3Al0.7N and Sc0.4Al0.6N lead to the loss of epitaxy, although the structure remains layered. For the negative lattice mismatched In-rich ScxAl1−xN/InyAl1−yN superlattices, a tensile biaxial stress promotes the stabilization of wurtzite ScxAl1−xN even for the highest investigated concentration x = 0.4. Ab initio calculations with fixed in-plane lattice parameters show a reduction in mixing energy for wurtzite ScxAl1−xN under tensile stress when x ⩾ 0.375 and corroborate the experimental results.9
Sternheimer antishielding factors of F<SUP>−</SUP>, Cl<SUP>−</SUP>, Br<SUP>−</SUP> and I<SUP>−</SUP>: influence of approximate free and crystal ion potentials
No full textSternheimer ionic antishielding factors, γ∞, have been calculated for F−, Cl−, Br−, and I− in crystals using the Watson model within the nonrelativistic Hartree-Fock approximation and the perturbation numerical procedure. The free ion calculations of γ∞ using the Hartree-Fock wave functions have also been carried out in order to ascertain the solid-state effects. The free ion values of γ∞ change from −22.2, −55.1, −135.106, and −248.1 to −10.3, −34.8, −75.6, and −148.7 in solids for F−, Cl−, Br−, and I−, respectively. A major part of the discrepancy between the free ionic γ∞ values based on the Hartree-Fock and Hartree-Fock-Slater wave functions, as noted by the previous workers, is shown to arise from an inaccurate description of the self-interaction potential in the conventional Slater exchange approximation
Quadrupole antishielding factors for F<SUP>−</SUP>, Cl<SUP>−</SUP>, and Br<SUP>−</SUP> using ≡a theory
No full textIt is shown that the use of the self-interaction-corrected ≡a method leads to the values of the Sternheimer quadrupole antishielding factor γ∞ for F−, Cl−, and Br− as −25, −65, and −146, respectively, which provide a significant improvement over the corresponding values of −41, −82, and −195 derived from the Xa wave functions. The Hartree-Fock estimates of γ∞ as given by −22, −55, and −155 for F−, Cl−, and Br−, respectively, are therefore approximated quite well by means of the ≡a wave functions
Magneto-optical studies of Cd1−x−yMnxCoyTe
No full textWe have investigated the optical absorption and magneto-optical properties of quaternary Cd1-x−yMnxCoyTeCd1-x−yMnxCoyTe crystals (x=0.37x=0.37, 0???y???0.0090???y???0.009) grown by the vertical Bridgman method. The presence of Co showed a significant enhancement of magneto-optical effects as compared to ternary Cd0.63Mn0.37TeCd0.63Mn0.37Te system with the same Mn content. Four features were observed in magnetic circular dichroism (MCD) spectra of these alloys, located near 1.37, 1.45, 1.82, and 2.13 eV. We present detailed temperature dependences of the position and intensity of these MCD features, and we discuss their possible origins.ope
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