206,198 research outputs found
Significance of the direct relaxation process in the low-energy spin dynamics of a one-dimensional ferrimagnet NiCu(C_7H_6N_2O_6)(H_2O)_3 2H_2O
In response to recent nuclear-magnetic-resonance measurements on a
ferrimagnetic chain compound NiCu(C_7H_6N_2O_6)(H_2O)_3 2H_2O [Solid State
Commun. {\bf 113} (2000) 433], we calculate the nuclear spin-lattice relaxation
rate 1/T_1 in terms of a modified spin-wave theory. Emphasizing that the
dominant relaxation mechanism arises from the direct (single-magnon) process
rather than the Raman (two-magnon) one, we explain the observed temperature and
applied-field dependences of 1/T_1. Ferrimagnetic relaxation phenomena are
generally discussed and novel ferrimagnets with extremely slow dynamics are
predicted.Comment: 5 pages, 5 figures embedded, Solid State Commun. 117, No. 1 (2000
Determination of Electrical Parameters for Skin during Galvanic Skin Reflex from Continuous Measurement
Skin impedance satisfies the Cole-Cole arc's law. The change of skin impedance during GSR (Galvanic Skin Reflex) can be expressed by the change of equivalent parallel resistance approximately. Using these characteristics, the complicated change of skin impedance during GSR can be determined continuously from the measurement value in one frequency point
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A case of eosinophilic fasciitis and generalized morphea overlap
A 60-year old man developed skin hardening and edema on his extremities. Although he had been treated with oral prednisolone at another hospital, skin stiffness relapsed during tapering of prednisolone. At the initial visit to our department, physical examination showed skin hardening of the extremities and also symmetric erythematous macules on the back. Histological examination revealed fasciitis on the forearm and morphea on the back. Eosinophilic fasciitis is occasionally associated with morphea. However, cases of concurrent eosinophilic fasciitis and generalized morphea are rare. In the present case, CD34 was differentially expressed in both lesions, suggesting eosinophilic fasciitis and morphea are separate diseases with different origin of mesenchymal cells
Ground-state properties of a Peierls-Hubbard triangular prism
Motivated by recent chemical attempts at assembling halogen-bridged
transition-metal complexes within a nanotube, we model and characterize a
platinum-halide triangular prism in terms of a Peierls-Hubbard Hamiltonian.
Based on a group-theoretical argument, we reveal a variety of valence
arrangements, including heterogeneous or partially metallic charge-density-wave
states. Quantum and thermal phase competitions are numerically demonstrated
with particular emphasis on novel insulator-to-metal and insulator-to-insulator
transitions under doping, the former of which is of the first order, while the
latter of which is of the second order.Comment: 9 pages, 7 figures. to be published in J. Phys. Soc. Jpn. Vol. 79,
No.
Photoinduced infrared absorption of quasi-one-dimensional halogen-bridged binuclear transition-metal complexes
We investigate the optical conductivity of photogenerated solitons in
quasi-one-dimensional halogen-bridged binuclear transition-metal MMX complexes
with particular emphasis on a comparison among the three distinct groups:
A_4_[Pt_2_(P_2_O_5_H_2_)_4_X]nH_2_O (X=Cl,Br,I; A=Na,K,NH_4_,...),
Pt_2_(RCS_2_)_4_I (R=C_n_H_2n+1_) and Ni_2_(CH_3_CS_2_)_4_I, which exhibit a
mixed-valent ground state with the X sublattice dimerized, that with the M_2_
sublattice dimerized and a Mott-Hubbard magnetic ground state, respectively.
Soliton-induced absorption spectra for A_4_[Pt_2_(P_2_O_5_H_2_)_4_X]nH_2_O
should split into two bands, while that for Pt_2_(RCS_2_)_4_I and
Ni_2_(CH_3_CS_2_)_4_I should consist of a single band. The excitonic effect is
significant in Ni_2_(CH_3_CS_2_)_4_I.Comment: 4 pages, 3 figure
Measurement of Emotional Response by Similarity in Patterns of Galvanic Skin Reflex
There is no doubt that many people feel the peace of mind or the pleasures of senses in appreciating music. But the estimation of the effect is very difficult and the objective estimation can be hardly done. This study proposed the objective estimating method of human emotion utilizing galvanic skin reflex (GSR) which reflects a human psychological activity. In this method, not by individual response, but by the series of response and pattern of appearance of GSR, the emotional response under appreciating music was investigated. In the case of appreciation of the same classic music to several subjects, the individual GSR responses are random and remarkable characteristic could not be find on the results. However, on the patterns of appearance of GSR, the patterns obtaining from the same generation are much similar each other and the patterns obtaining from different generation are less similar. It was cleared that the same music gave different effect on different generations
Nuclear spin relaxation in ordered bimetallic chain compounds
A theoretical interpretation is given to recent proton spin relaxation-time
(T_1) measurements on NiCu(C_7H_6N_2O_6)(H_2O)_32H_2O, which is an ideal
one-dimensional ferrimagnetic Heisenberg model system of alternating spins 1
and 1/2. The relaxation rate T_1^{-1} is formulated in temrs of the spin-wave
theory and is evaluated by the use of a quantum Monte Carlo method.
Calculations of the temperature and applied-field (H) dependences of T_1^{-1}
are in total agreement with the experimental findings. T_1 behaves as
, which turns out an indirect observation of the
quadratic dispersion relations dominating the low-energy physics of quantum
ferrimagnets.Comment: 5 pages, 4 figures embedded, to appear in Phys. Lett.
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