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31.
32.
This paper describes a new photoelastic technique for the spatiotemporal stress analysis. In a polarimeter developed, an elliptically
polarized signal beam of light, modulated in state of polarization by two-dimensional principal-stress distributions interferes
with a reference beam of light consisting of orthogonal linearly polarized two components. A time-sequential series of two-dimensional
interference patterns are received one after another by a MOS video camera, followed by a computer. Of the elliptically polarized
signal beam, the orthogonal field components along the directions of the principal stresses in a two-dimensional photoelastic
sample can be computed from a recorded interference pattern, which offer the data needer for mapping the spatiotemporal principal-stress
distribution over the sample. Not only each of the two orthogonal principal stresses but also the principal-stress difference
are mapped in a time-sequential diagram. No use of any movable polarization element such as a rotating analyzer allows us
to follow a rapid change in stress distribution within the maximum frame rate 2066 s−1 of the MOS video camera. 相似文献
33.
Satoshi Tanaka Kazuaki Yoshida Seiichiro Kinugasa Yoshihiro Ohtsuka 《Optical Review》1997,4(1):A92-A95
Novel birefringent single-mode fibers are fabricated with a vacant hole on either side of the central elliptical core, referred to as side-hole fiber, and their intrinsic and tension-induced modal birefringences are measured to know their characteristic properties for the purpose of making a strain sensor. Five sampled side-hole fibers are prepared for measurements. The sensitivity of the strain sensor is primarily determined by two parameters, tension-induced and intrinsic modal birefringences. Tension-induced modal birefringence is controllable by optimal arrangement of the size and location of the side-holes in the cross-section of the fiber. A sensitivity diagram for designating and fabricating side-hole fibers is presented. 相似文献
34.
35.
The mechanism of GMR effects in La(Mn1–x
Fe
x
)O3 (x=0, 0.01, 0.03) oxides has been investigated by means of magnetic measurements, resistivity measurements in magnetic field and Mössbauer spectroscopy. For the x=0.01 sample, the GMR behavior is similar to that of the conventional (La, A)MnO3 (A: divalent cations) oxides. For the x=0.03 sample, even though the temperature dependence of the Mössbauer spectra was similar to that of the x=0.01 sample, the mechanism for the occurrence of the GMR effect seems to be different. The x=0 sample shows a similar behavior to the x=0.03 sample. A thermal stabilization of spin fluctuation is proposed for the x=0 and x=0.03 sample. 相似文献
36.
O6-Methylguanosine derivative was treated with sodium nitrite or isoamylnitrite in the presence of carboxylic acid to give the purin-2-yl carboxylate, an unusual product bearing a carboxylic group at the 2-position of the purine moiety. 相似文献
37.
A. Faessler M. Rashdan M. Ismail N. Ohtsuka W. Wadia 《Zeitschrift für Physik A Hadrons and Nuclei》1989,333(2):153-162
The effect of nuclear and Coulomb interactions on the shapes of two colliding208Pb nuclei at finite temperature is investigated. The complex potential energy density derived by Faessler and collaborators and the kinetic energy density and entropy density for two Fermi spheres at finite temperature are used to calculate the free energy of the208Pb +208Pb system in the energy density formalism. Shell corrections are added to the free energy in the framework of the Strutinsky method. The total free energy is minimized with respect to the quadrupole deformation and the diffuseness to determine the density distribution of208Pb nucleus at certain distanceR and temperatureT assuming the deformed Woods-Saxon shape for each nucleus. It is found that the nucleus acquires larger deformation and diffuseness as the temperature increases. The interaction potential between two208Pb nuclei is calculated from the minimized free energy. The total (nuclear + Coulomb) potential is found to decrease with increasing temperature, whereas the real part of the nuclear potential becomes more repulsive as the temperature increases. 相似文献
38.
Sadanori Konishi 《Annals of the Institute of Statistical Mathematics》1985,37(1):87-94
Summary A concept of normalizing transformations of statistics is constructed on the basis of the rate of convergence to normality.
The concept is applied to derive a normalizing transformation of a maximum likelihood estimate of intraclass correlation coefficient
in ap-variate normal sample. Numerical comparisons are made to examine whether the proposed transformation is efficient to achieve
normality. The relationship between normalization and variance stabilization is also considered.
The Institute of Statistical Mathematics 相似文献
39.
Intermediate energy nuclear photoabsorption and Compton scattering within the Δ-hole approach are studied. The same Δ-nucleus dynamics used to describe a variety of pion-induced reactions are employed. A dynamical model for the photon-nucleon amplitude is constructed, including both resonant-channel and nonresonant backgrounds in addition to Δ-excitation. Medium corrections to the full amplitude are included for nuclear seattering. A doorway state expansion allows one to discuss quantitatively the role of various contributions to the Δ-hole Hamiltonian, thereby clarifying the level of sensitivity to the structure of the Δ spreading potential. The reactive content of the total cross section is diseussed. The results are compared with available photoabsorption data for 4He, 12C and 16O. We present results for the Δ contribution to the electron seattering transverse response function, for coherent π0 photoproduction, and for nuclear elastic Compton seattering. The photoabsorption strength is spread over a larger energy range by the Δ dynamics, in agreement with the data, but is centered at too high an energy. The helicity flip Compton cross section is especially sensitive to the Δ-nucleus interaction, such as the spin-orbit potential strength. 相似文献
40.