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61.
This note gives the correct form of a result (Theorem 2, p. 478) published recently in [Math. Slovaca 60 (2010), 471–484]. 相似文献
62.
The ultrasonic attenuation coefficient of a fluid or solid is an acoustic parameter routinely estimated for the purpose of materials characterization and defect/disease detection. This paper describes a broadband attenuation coefficient estimation technique that combines two established estimation approaches. The key elements of these two approaches are: (1) the use of magnitude spectrum ratios of front surface, first back surface, and second back surface reflections from interfaces of materials with plate-like geometries, and (2) the use of an experimental diffraction correction approach to avoid diffraction losses. The combined estimation approach simplifies the attenuation coefficient estimation process by eliminating the need to explicitly make diffraction corrections or calculate reflection/transmission coefficients. The approach yields estimates of the attenuation coefficient, reflection coefficient, and material density. Models, experimental procedures, and signal analysis procedures, which support implementation of the approach, are presented. Attenuation coefficient and reflection coefficient estimates are presented for water and solid samples with estimates based on measurements made with multiple transducers. 相似文献
63.
We investigated the structural and dielectric dynamics of nanocolloids comprising lyotropic liquid crystals and bismuth titanate (Bi4Ti3O12) spherical nanoparticles (≈16–18 nm) of varying concentration 0.05 and 0.1 wt%. The lyotropic liquid crystalline mixture was prepared by a binary mixture of cetylpyridinuium chloride and ethylene glycol mixed in 5:95 wt% ratio. Binary lyotropic mixture exhibited hexagonal lyotropic phase. Structural and textural characterizations of nanocolloids infer that the nanoparticles were homogeneously dispersed in the liquid crystalline matrix and did not perturb the hexagonal ordering of the lyotropic phase. The dielectric constant and dielectric strength were found to be increased with the rise in the Bi4Ti3O12 nanoparticles concertation in the lyotropic matrix. A significant increase of one order was observed in the ac conductivity of colloidal systems as compared to the non-doped lyotropic liquid crystal. Relaxation parameters of the non-doped lyotropic liquid crystal and colloidal systems were computed and correlated with other parameters. 相似文献
64.
In this paper we establish certain inequalities for the Fox’s H-function with the help of certain known inequalities for the generalized hypergeometric function. 相似文献
65.
66.
Spherulitic crystals of neodymium and dysprosium tartrates have been grown by controlled diffusion in silica gel. The operative mechanisms of crystallization are discussed and the morphological development of the spherulites is described. The adsorption property of gel is observed to play an important role in the growth of the spherulitic crystals. 相似文献
67.
The current work presents the multilevel approach of the embedded finite element method which is obtained by combining features of the method of domain decomposition with those of the standard embedded finite element method. The conventional requirement of fine mesh in a possible failure zone is rendered unnecessary with the new approach thereby reducing the computational expense. In addition, it is also possible to stop a propagating crack-tip in the middle of a finite element. In this approach, the finite elements at the failure-prone zone where cracks or shear bands, referred to as strong discontinuities which represent jumps in the displacement field, can form and propagate based on some failure criterion are treated as separate sub-boundary value problems which are adaptively discretized during the run time into a number of sub-elements and subjected to a kinematic constraint on their boundary. Each sub-element becomes equally capable of developing a strong discontinuity depending upon its state of stress. A linear displacement based constraint is applied initially which is modified accordingly as soon as a strong discontinuity propagates through the boundary of the main finite element. At the local equilibrium, the coupling between the quantities at two different levels of discretization is obtained by matching the virtual energies due to admissible variations of the main finite element and its constituent sub-elements. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
68.
In this study, cadmium sulphide (CdS) nanorods doped ferroelectric liquid crystal (FLC) sample cells have been prepared and studied. A memory effect has been observed in CdS nanorods (≤0.3?wt%) doped FLC mixture and confirmed by textures, dielectric and optical studies. The addition of nanorods increases the memory behaviour and efficiency. The occurrence of memory behaviour has been explained due to charge transfer from liquid crystal molecules to CdS nanorods and exists there for 5–15?min in 0.1–0.3?wt% CdS nanorods doped samples. An improvement in polarization, switching time, threshold voltage and rise time parameters has also been noticed in CdS nanorods doped FLC samples. 相似文献
69.
We present the results based on the electro-optic and dielectric properties of silica nanoparticle (SNP) doped ferroelectric liquid crystal (FLC) in SmC* phase. Switching time, spontaneous polarization and rotational viscosity decreases with increase in the silica concentration. An improvement in switching time after doping the silica nanoparticle is due to enhancement in anchoring energy exist between silica nanoparticle and ferroelectric liquid crystal. We noticed that the dielectric permittivity and dielectric strength decreases with increasing the concentration of silica nanoparticle in SmC* phase. Relaxation frequency increases with increasing the silica concentration and temperature in SmC* and decreases as we approaches towards transition temperature. 相似文献
70.
Quarks are color charged particles. Due to their motion there is a strong possibility of generation of color magnetic field.
It is shown that however hadrons are color singlet particles they may have non-zero color magnetic moment. Due to this color
magnetic moment hadrons can show color interaction. In this paper we have studied the chromomagnetic properties of nuclear
matter. 相似文献