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21.
It is investigated to what extent the well-known algebra \(\left\{ {Q^S ,\bar Q^S } \right\} = \gamma ^\mu P_\mu \) in the rigid supersymmetry theory holds in quantum supergravity: The anti-commutator \(\left\{ {Q_\alpha ^S ,\bar Q_\beta ^S } \right\} = \gamma ^m \tilde P_m \) defines an “internal” translation generator \(\tilde P_m \) , quite another from the “external” translation generatorP μ. It is, however, shown that those two operators give the same matrix elements between any two physical states aside from a proportional factor. Such a “miracle” is caused by some particular properties of global gauge transformation charge universal in gauge theories. These properties are fully clarified in a general manner.  相似文献   
22.
We investigate the vacancy effect on the electronic transport properties of the (5,5)-metallic and (5,0)-semiconducting carbon nanotubes using the time-dependent wave-packet approach based on the Kubo-Greenwood formula within the tight-binding approximation. We found that the metallic and semiconducting carbon nanotubes show different electronic transport properties for the states created by vacancies.  相似文献   
23.
We developed a compact equipment working at 94 GHz to replace the commonly used network analyzer for nondestructive testing of materials. The compact equipment was designed to measure the variations in the amplitude and phase of the reflected signal from the material relative to a reference signal. A good accuracy of the amplitude and phase measurement of the equipment was obtained in the confirmative experiments. The distribution of a drop of water in a wood plate is clearly visible in the millimeter wave images obtained by the amplitude and phase measurement.  相似文献   
24.
We evaluated whether apparent diffusion coefficient (ADC) value is more useful than signal intensity for differentiating endometrial cysts from other pelvic cysts. In an in vitro study, signal intensity and diffusion coefficients were measured in whole blood phantoms in which blood oxidation was gradually increased and concentration subsequently diluted. Although both signal intensity and diffusion value were largely affected by blood concentration, diffusion value was almost independent of blood oxidation and red blood cell lysis-related diminution of magnetic nonhomogeneity, both factors greatly affecting signal intensity on T1- and T2-weighted images. In an in vivo study, differentiation between endometrial and other pelvic cysts was attempted by means of ADC values and signal ratios of cysts to muscles on T1- and T2-weighted images (T1- and T2-ratios). Endometrial cysts tended to show lower T2-ratios, higher T1-ratios, and lower ADC values than other pelvic cysts (p < 0.001). However, ADC values were not correlated with T1- and T2-ratios (p < /0.15/). The ability of ADC value to discriminate between these two groups (discriminant rate, 91.4%) was higher than that of T2-ratio (71.4%) or T1-ratio (88.6%). If combined, ADC and T1-ratio (or T2-ratio) showed higher discriminant rate (94.3%) than the combination of T1- and T2 ratios (88.6%). ADC value might be useful for evaluating the blood concentration of a cystic lesion, because diffusion value is more closely related to blood concentration and almost independent of blood oxidation and red blood cell lysis that largely affect signal intensity.  相似文献   
25.
Psychiatric and neurological disorders severely hamper patient’s quality of life. Despite their high unmet needs, the development of diagnostics and therapeutics has only made slow progress. This is due to limited evidence on the biological basis of these disorders in humans. Synapses are essential structural units of neurotransmission, and neuropsychiatric disorders are considered as “synapse diseases”. Thus, a translational approach with synaptic physiology is crucial to tackle these disorders. Among a variety of synapses, excitatory glutamatergic synapses play central roles in neuronal functions. The glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) is a principal component of glutamatergic neurotransmission; therefore, it is considered to be a promising translational target. Here, we review the limitations of current diagnostics and therapeutics of neuropsychiatric disorders and advocate the urgent need for the promotion of translational medicine based on the synaptic physiology of AMPAR. Furthermore, we introduce our recent translational approach to these disorders by targeting at AMPARs.  相似文献   
26.
The electrical conductivities of carbon-black-filled low-density polyethylene (LDPE), poly(methyl methacrylate) (PMMA), and poly(vinyl chloride)-vinyl acetate (PVC/ VAc) copolymer were measured as functions of carbon content and melt viscosity of the matrix at the temperatures at which the composites were prepared. Sharp breaks in the relationship between the carbon filler content and the conductivity of composites were observed in all specimens at some content of the carbon filler. The conductivity jumps as much as 10 orders of magnitude at the break point. This phenomenon has been known as the “percolation threshold”. The critical carbon content corresponding to the break point  相似文献   
27.
The effect of solid-solution alloying on grain boundary sliding (GBS) was investigated using pure magnesium and six kinds of Mg–X (X?=?Ag, Al, Li, Pb, Y and Zn) dilute binary solid solutions with an average grain size of 10?µm. A sharp increase in damping capacity caused by GBS was observed above a certain temperature. The temperature at which a sharp increase in damping capacity occurred depended on the alloying element. The addition of Y and Ag markedly increased the onset temperature (more than 100?K) for a sharp increase in damping capacity, whereas the addition of Zn, Al and Li slightly increased the onset temperature (less than 50?K) as compared with that for pure magnesium. Tensile tests at a temperature of 423?K revealed that the higher the onset temperature, the lower the strain rate sensitivity of the flow stress. It is suggested that the former elements (Y and Ag) are more effective in suppressing GBS in magnesium alloys than the latter ones (Zn, Al and Li). The suppression of GBS was associated with low grain boundary energy, and the extent to which the energy is reduced depended on the alloying element. It was suggested that the change in the lattice parameter (the so-called c/a ratio) affects the grain boundary energy, and thus, the occurrence of GBS.  相似文献   
28.
X-ray fluorescence spectra of copper (Cu) metal, copper monoxide (CuO), and potassium chromate (K2CrO4) were recorded as a function of incident X-ray energy near the Cu K-edge and chromium (Cr) K-edge, respectively, using a conventional silicon drift detector. The spectra contained components due to elastic, inelastic, and multiple scattering, in addition to the Kα and Kβ lines. Cu and Cr K-edge X-ray absorption fine structure (XAFS) spectra of Cu, CuO, and K2CrO4 were obtained by an intensity analysis of the Kα and Kβ lines. The intensity of the Kβ line for the different incident photon energies was obtained by numerically removing the additional scattering components using the MUSCAT program. These spectra exhibited a jump near the K absorption edges, which reproduced the spectral features obtained in transmission mode for both Cu, CuO, and K2CrO4. A chemical shift was also clearly identified in the X-ray absorption near edges structure using the X-ray fluorescence Kβ line. In addition, the Cr K-edge extended XAFS spectrum of K2CrO4 was clearly observed using the Cr Kβ fluorescent line. The XAFS measurements on the Kα and Kβ lines are possible, and they carry equally valuable information.  相似文献   
29.
Summary The purpose of the present paper is to propose an analytical method for ordered categorical responses obtained from a repeated measurement/longitudinal experiment. The ordered categorical scale is assumed to be a manifestation of a latent quantitative variable. A linear model is assumed for location parameters of the underlying distributions. Weighted least square method is applied to parameter estimation and subsequent analysis. Two data sets are analyzed to show several aspects of analysis by the proposed model and to discuss comparative characteristics of analysis compared with earlier analysis. A mention is made for a computer software program for the proposed model.  相似文献   
30.
A low drive-voltage optical modulator using a Ti-diffused UNbO3 optical waveguide has been fabricated. Stabilization against ambient temperature change was realized by using a miniature halfwave plate. The halfwave voltage, 3 dB bandwidth, optical insertion loss and extinction ratio were 3·8 V (at 1·06m wavelength), 850 MHz, 10 dB and 13 dB, respectively. A reduction scheme for the optical absorption caused by metallic electrodes, and an analysis of the modulator high frequency response are also reported.  相似文献   
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