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941.
G. S. Patrin V. V. Beletskiĭ D. A. Velikanov O. A. Bayukov V. V. Vershinin O. V. Zakieva T. N. Isaeva 《Physics of the Solid State》2006,48(4):700-704
The results of experimental and theoretical studies of the low-temperature properties of FeSi crystals are presented. The specific features of the magnetic susceptibility are shown to be related to the superparamagnetic behavior of impurity clusters. The thermomagnetic hysteresis phenomena observed are explained using the model of exchange-coupled clusters. 相似文献
942.
The proton magnetic resonance spectra of water molecules diffusing over regular sites in natrolite are numerically simulated. Experimental data and the results of simulation are found to be in good agreement in a wide temperature interval including the transition range, where the magnetic resonance spectrum is a superposition of a wide unaveraged spectrum and a spectrum averaged by the motion of molecules. The simulation uses generators of pseudorandom-number Markovian sequences. For a binary Markovian process, it is shown, in particular, that the time within which a physical quantity remains constant is described by an exponentially distributed random number. 相似文献
943.
Within the framework of fractal analysis and percolation theory, an alternative model of reinforcement of filled polymers
is offered. Practically, this model can be used only to describe the reinforcement of nanocomposites, because, according to
the treatment considered, a pronounced reinforcement can be reached only at ratios of filler particle diameter to the statistical
segment length of about 10 and less. A theoretical calculation showed a good qualitative and quantitative agreement with experiments.
The type of reinforcement mechanism of composites is determined by the type of the space (fractal or Euclidean) in which the
structure of the polymeric matrix is formed.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 6, pp. 797–802, November–Decem ber, 2006. 相似文献
944.
High temperature GaN layers have been grown on Si (1 1 1) substrate by metalorganic vapor phase epitaxy (MOVPE). AlN was used as a buffer layer and studied as a function of thickness and growth temperature. The growth was monitored by in situ laser reflectometry. High resolution X-ray diffraction (HRXRD) revealed that optimized monocrystalline GaN was obtained for a 40 nm AlN grown at 1080 °C. This is in good agreement with the results of morphological study by scanning electron microscopy (SEM) and also confirmed by atomic force microscopy (AFM) observations. The best morphology of AlN with columnar structure and lower rms surface roughness is greatly advantageous to the coalescence of the GaN epilayer. Symmetric and asymmetric GaN reflections were combined for twist and stress measurements in monocrystalline GaN. It was found that mosaicity and biaxial tensile stress are still high in 1.7 μm GaN. Curvature radius measurement was also done and correlated to the cracks observations over the GaN surface. 相似文献
945.
K.E. Lee T.L. Phan N.D. Ha M.H. Phan S.C. Yu C.O. Kim 《Journal of magnetism and magnetic materials》2006
Influences of oxygen-partial pressure and annealing on the electrical and magnetic properties of CoFeAlO thin films were systematically investigated by means of resistivity, permeability, magnetization and ferromagnetic resonance (FMR) measurements. It was found that, with increasing oxygen-partial pressure or under annealing, the electrical resistivity of the film increased and the magnetic softness decreased, which is attributed to the microstructural change of the film. Interestingly, an as-deposited Co45.30Fe20.65Al19.34O14.71 film was found to exhibit an inverted hysteresis loop with negative coercivity, and this peculiar phenomenon disappeared upon effects of oxygen-partial pressure and annealing. It was also found that the as-deposited films owned a narrow FMR line width that increased with increasing oxygen-partial pressure or under annealing. 相似文献
946.
947.
The possibility that pairs of quarks will form diquark clusters in the regime above deconfinement transition for hadron matter
at finite density is revisited. Here we present the results on the diquark-diquark (dq-dq) interaction in the framework of
constituent quark model taking account of spin, isospin and color degrees of freedom in the spirit of generalized Pauli principle.
By constructing the appropriate spin and color states of the dq-dq clusters we compute the expectation values of the interaction
Hamiltonian involving pairwise quark—quark interaction. We find that the effective interaction between two diquark clusters
is quite sensitive to different configurations characterized by color and spin states, obtained after the coupling of two
diquark states. The value of the coupling parameter for a particular color—spin state, i.e., -3, 1 is compared to the one
obtained earlier by Donoghue and Sateesh,Phys. Rev.
D38, 360 (1988) based on the effective Φ4-theory. This new value of λ derived for different color-spin dq-dq states, may lead to several important implications in
the studies of diquark star and diquark gas. 相似文献
948.
T. Kasahara H.S. Park D. Shindo H. Yoshikawa T. Sato K. Kondo 《Journal of magnetism and magnetic materials》2006
Domain wall motion in Mn–Zn and Ni–Zn ferrites with applied magnetic fields is investigated by in situ observations with Lorentz microscopy and electron holography. It is found that both Mn–Zn and Ni–Zn ferrites have a mean grain size of approximately 10 μm and several pores with sizes ranging from 0.2 to 1.1 μm. In situ observations by Lorentz microscopy with an applied magnetic field reveals that in Mn–Zn ferrite, the domain walls move easily across the grain boundary, while in Ni–Zn ferrite, the domain walls move along the grain boundary but are pinned at the grain boundary and pores. From in situ observations of Ni–Zn ferrite by electron holography, it is clarified that domain wall pinning at the grain boundary retards a sensitive increase in magnetic flux parallel to the applied field direction, which is considered to result in high hysteresis loss. 相似文献
949.
950.
A one-dimensional nanodusty plasma was modeled by self-consistently coupling a plasma model with nanoparticle growth, charging,
and transport models. As nanoparticles grow from subnanometer to tens of nm in diameter, the numerical results predict a rich
spatiotemporal structure, including four distinct temporal phases: a charge-limited phase, a charge accumulation phase, an
early ion drag phase, and a sheath interaction phase. 相似文献