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1.
After discussing various points raised in a recent comment by F. Ko?íšek et al., who claim that our Letter “Evidence for the existence of stable-water-clusters at room temperature and normal pressure” (Phys. Lett. A 373 (2009) 3872) is unclear and the evidence is scant, we conclude that their arguments are wrong.  相似文献   

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Particles of Fe oxide were prepared by chemical coprecipitation and their sizes were shown by TEM and confirmed by XRD to be in the range of 5 nm. The Mössbauer spectra at 120K clearly indicated the absence of magnetite and presence of the maghemite (γ-Fe2O3) phase.We studied the transition of the system to superparamagnetic behaviour, which strongly depends on the relevant time window amounting to ~ 10?7 s for Mössbauer spectroscopy of 57Fe and units of seconds for d.c. magnetic measurements. From the temperature dependences of magnetic moments of zero-field-cooled (ZFC)) and field-cooled (FC) samples, the distributions of blocking temperatures were determined. The comparison of the transition temperatures derived from these two types of measurements gave an independent estimate for the pre-exponential factor and the energy barrier and thus magnetocrystalline anisotropy in an order-of-magnitude agreement with the published data for bulk γ-Fe2O3.  相似文献   

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The temperature dependence of the magnetic susceptibility of La2NiO4+δ single crystals with δ = 0.095 and 0.105 has been analyzed. The anomalous dependence of χ(T) characteristic of stripe structures previously found in La1.8Sr0.2NiO4 has been found. Investigation of the dependence χ(T) on the impurity and charge disorder degrees makes it possible to separate the contribution associated with the ordering of holes and impurity oxygen. It has been shown that the contribution from the ordering of holes is well described by the model of ferromagnetic Heisenberg chains of spins S = 1/2. The length of the chains and intrachain interaction J N have been determined from the temperature dependence χ(T).  相似文献   

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An exhaustive study of the structural and magnetic properties of Fe7?n Pt n with n = 0, 1, 2, …7, bimetallic clusters is presented. Based on ab initio density functional theory that includes spin-orbit coupling (SOC) and graph theory, the ground state geometry, the local chemical order, and the orbital and spin magnetic moments are calculated. We show how the systems evolves from the 3-d Fe to the quasi-planar Pt clusters. These calculations show that SOC are necessary to describe correctly the composition dependence of the binding energy of these nanoalloys. We observe that the ground state geometries on the Fe rich side resemble the fcc structure adopted by bulk samples. Furthermore, we observe how the spin and orbital magnetic moments depend on the chemical concentration and chemical order. Based on these results, we estimated the magnetic anisotropy energy and found that the largest values correspond to some of the most symmetric structures, Fe5Pt2 and FePt6. To determine the degree of non-collinearity, we define an index that shows that in FePt6 the total magnetic moments, on each atom, are the less collinear.  相似文献   

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This paper aims to prove the inaccuracy of the Navier solution presented by Aghababaei and Reddy [1] for the bending analysis of nanoplates based on the nonlocal theory of Eringen. According to the derived relations for bending of the nonlocal plate model, the main cause of this inaccuracy is attributed to an incorrect approximation of the Navier solution for a uniform transverse load. Of course, this problem does not inherently occur for the Navier solution in cases such as free vibration or the buckling of a nonlocal plate model in which the amount of transverse load is zero. In order to obtain further verification the results reported based on the Navier solution by Aghababaei and Reddy (2009, [1]) for the bending analysis of a nanoplate are compared with those computed by the differential quadrature (DQ) and finite difference (FD) methods. As shown, the results obtained by both the FD and DQ methods are consistently alike and unlike the solutions reported by Aghababaei and Reddy (2009, [1]) they are independent from small scale effect.  相似文献   

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Dusty plasmas exist almost everywhere in the Universe and relevant nonlinear studies are encouragingly going to non-planar geometry. On our recent construction of a spherical Kadomtsev–Petviashvili model for the dust-ion-acoustic waves in a cosmic dusty plasma [B. Tian, Y.-T. Gao, Phys. Lett. A 340 (2005) 243], Hong [W.P. Hong, Phys. Lett. A (2006), doi:10.1016/j.physleta.2006.11.021, in press] comments that certain interesting coordinate transformations exist, with presentation of a transformed equation (TE) and nebulon solutions. In this Reply, we point out that the TE is valuable to the studies on both cosmic plasmas and applied mathematics. We obtain an auto-Bäcklund transformation on the TE and more general nebulons. With series of pictures, we discuss nebulon structures out of the TE, and address that there are cosmic plasma systems for which the TE is valid. We remove a constraint set in that Comment so that the TE can be useful for the Saturn-F-ring-typed dusty plasmas as well.  相似文献   

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We link the Boundary Control Theory and the Titchmarsh-Weyl Theory. This provides a natural interpretation of the A?amplitude due to Simon and yields a new efficient method to evaluate the Titchmarsh-Weyl m?function associated with the Schrödinger operator H = ?? x 2  + q(x) on L 2(0, ∞) with Dirichlet boundary condition at x = 0.  相似文献   

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In this note we discuss and solve several open problems posed in our recent paper “Geometrical and topological aspects of electrostatics on Riemannian manifolds”, also published in this journal. Some minor mistakes therein are corrected as well.  相似文献   

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Golmakani and Rezatalab [1] suggested in their paper that the deflection of a simply supported nonlocal elastic plate under uniform load is not affected by the small length scale terms. They based their proof on the use of Navier?s method using a sinusoidal-based deflection solution. This insensitivity of the deflection solution of a simply supported nonlocal elastic plate with respect to the small length terms of Eringen?s model is not correct, as already detailed in the literature (for example, see [2] for beam problems). In fact, the deflection of the nonlocal plate (in the Eringen sense) is larger than the one of the local case, as shown in many papers available in the literature. We prove in this reply to the authors that the Navier?s method has to be correctly applied for highlighting the specific sensitivity phenomenon of the deflection solution, as compared to exact analytical solution.  相似文献   

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One-dimensional nanocomposites Zn1–x Co x O1–y С у :nCo3O4 and solid solutions Zn1–x Co x O1–y С у , which are promising photocatalysts for the oxidation of toxic organic compounds in visible light, are obtained via the thermolysis of Zn1–x Co x (HCOO)(OCH2CH2O)1/2 (0.1 ≤ x ≤ 0.5) precursor in a controlled gaseous atmosphere.  相似文献   

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<正>These two volumes can really be recommended to anyone interested in vibro-acoustics or the field of sound and vibration.The two volumes include 16 chapters and some 890 pages.The work is the result of cooperation between the Key Laboratory of Acoustics,The Chinese Academy of Sciences and The Royal Institute of Technology,KTH.The topic describes how structures are excited,energy flows from an excitation point to a sound radiating surface,and  相似文献   

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We investigate the problem of computing $$\lim_{N \to \infty}\frac{1}{aN}\log EZ_N^a$$ for any value of a, where Z N is the partition function of the celebrated Sherrington-Kirkpatrick (SK) model, or of some of its natural generalizations. This is a natural “large deviation” problem. Its study helps to get a fresh look at some of the recent ideas introduced in the area, and raises a number of natural questions. We provide a complete solution for a ≥ 0.  相似文献   

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A new method of analysis of resonant parameters in the framework of the J-matrix inverse scattering formalism is proposed. The method is applied to analysis of scattering in various partial waves. The obtained 1/2? and 3/2? resonance energies and widths in 5He and 5Li nuclei are in good agreement with the results of other approaches. The eigenenergies entering the J-matrix phase shift parameterization are shown to correlate well with the respective results of no-core shell model calculations, in particular, in the case of non-resonant s-wave scattering.  相似文献   

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The electronic energy structure of 2H and 3C AlN and BN crystals and BxAl1?xN solid solutions is calculated on the basis of the local coherent potential method using the cluster version of the MT approximation and the theory of multiple scattering. The features of the electronic structure of 2H-AlN crystals are compared with x-ray K and L absorption and emission spectra of aluminum and nitrogen. An interpretation of these features is given. The concentration dependences of the width of the upper subband of the valence band and the band gap in BxAl1?xN solid solutions (x = 0.25, 0.5, 0.75) are investigated. Charge transfer from aluminum to nitrogen atoms is shown to occur and increase with boron doping in both crystallographic modifications.  相似文献   

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