Showing papers by "Waseda University published in 1968"
TL;DR: The reproduction problems of the original signals from the nonuniformly sampled pulse trains are discussed, from the standpoints of both the exact and approximate theories.
Abstract: The sampling principle for continuous signals specified by time-varying spectra with time-varying bands is studied theoretically. In the first place, the expansion corresponding to the usual sampling theorem is introduced for the representation of such a signal, and then the essential properties are briefly shown. Also, the reproduction problems of the original signals from the nonuniformly sampled pulse trains are discussed, from the standpoints of both the exact and approximate theories.
55 citations
45 citations
TL;DR: In this article, the correction of Lorentz field coefficients in a Perovskite-type crystal is discussed by considering orthorhombic deformation of a simple cubic lattice.
29 citations
TL;DR: In this paper, the authors studied the nucleation of gold deposits on the cleavage surface of NaCl and KCl and showed that selective nucleation occurs on imperfection sites such as point defects and impurities, and that random one occurs on defect-free surfaces at relatively higher deposition rate.
Abstract: Nucleation of gold deposits on the cleavage surface of NaCl and KCl has been studied as a function of substrate temperature and incidence rate. Experimental results on vacuum cleaved surface indicate that selective nucleation occurs on imperfection sites such as point defects and impurities, and that random one occurs on defect-free surfaces at relatively higher deposition rate. The deposits on color-centered surfaces of NaCl produced by X-ray irradiation showed an increase of nucleation density compared with that on the normal cleavage surfaces and an enhancement of (100) parallel epitaxy at relatively lower substrate temperature. It appears that the controlled production of point defects has an important role in nucleation and growth. The nature of nucleation sites is discussed in connection with the epitaxial growth of deposits.
28 citations
TL;DR: The d.c. electrical conductivity of poly-γ-benzyl-L -glutamate (PBLG), nylon 66 and calf thymus DNA has been investigated experimentally as the examples of hydrogen-bonded polymers.
Abstract: The d.c. electrical conductivity of poly-γ-benzyl- L -glutamate (PBLG), nylon 66 and calf thymus DNA has been investigated experimentally as the examples of hydrogen-bonded polymers. Energy gaps which are assumed to be the twice of the activation energy are determined by the temperature variation of conductance in the solid dry state; 2.07±0.05 eV for PBLG in α-helix, 2.00±0.05 eV for helical DNA, 4.92±0.05 eV and 1.85±0.05 eV respectively for higher and lower temperature regions of nylon 66 in α-form. The adsorption of polar or nonpolar molecules (H 2 O, CH 3 OH, C 6 H 6 ) has the effect of increasing the conductivity and decreasing the activation energy of conduction. These results are in disagreement with the values expected from recent theoretical investigations and spectroscopic studies of these samples. Possible conduction mechanisms for these polymers are proposed in the case of solid dry state as well as of the state adsorbing polar or nonpolar molecules.
21 citations
TL;DR: In this paper, the catalytic action of the zeolite-hydrogen chloride system in cumene cracking was investigated using a flow apparatus, and the activation energy by the former was about two-thirds of that by the latter.
19 citations
19 citations
TL;DR: In this article, the linewidth of the Rayleigh scattered light from flexible polymers is calculated on the basis of the Rouse model, and the contributions from translational diffusion and intrachain molecular motion are interrelated.
Abstract: The linewidth of the Rayleigh scattered light from flexible polymers is calculated on the basis of Rouse model In general, the contributions from translational diffusion and intrachain molecular motion are interrelated, but, for usual cases where the size of molecule is comparable to or less than the wave length of the incident light, the result is approximately expressed as a simple superposition of separate effects The linewidth due to the translational motion decreases with decreasing scattering angle, whereas the linewidth due to the intrachain molecular motion remains constant The ratio of magnitudes of these two effects is overwhelmingly large, and the effect of intrachain molecular motion seems almost indetectable
17 citations
15 citations
TL;DR: In this paper, the Pariser-Parr-Pople (PPP) approximation was used to compare the electronic structures of the normal and tautomeric forms of DNA bases.
Abstract: ASMO-SCF-CI calculations on the DNA-bases with both the normal and the tautomeric forms are carried out within the framework of the π-electron approximation and in terms of the Pariser-Parr-Pople approximation. The comparison between the electronic structures of the two forms is systematically made. The electronic structures for the anion, the cation and the first-triplet states of the bases are also calculated by means of the unrestricted Hartree-Fock method. It is shown that there is a close resemblance between the electronic states of the normal bases and those of the tautomeric ones: A↔G * , U↔C * , G↔A * and C↔U * . It is also shown for each of the bases that the excitation to triplet states and the ionization lead to large redistributions of π-electron densities whereas the excitation to singlet states does not. The calculated excitation energies for singlet states are in close agreement with observed ultra-violet absorption date on the lowest three absorption bands.
14 citations
TL;DR: In this paper, the energy bands for both the H -bonded and the main polypeptide-chain in the case of the β-structures and of the α-helix are calculated in terms of the LCMO and the nearest-neighbor approximation.
Abstract: Using the MO's for π-electrons in an isolated peptide group which are determined such that the ASMO-SCF-CI calculation reproduces the observed wavelength of the optical absorption maximum, the energy bands for both the H -bonded and the main polypeptide-chain in the case of the β-structures and of the α-helix are calculated in terms of the LCMO and the nearest-neighbor approximation. It is shown that the shifts of bands for main peptide chains are of the considerable order of -0.2∼-0.8 eV, and that in each case the band widths for main peptide chain are generally far larger than those for H -bonded polypeptide, especially those of the highest valence and the conduction band for main chain in α-helix have remarkably large values of the order of 1∼2 eV. The π-electronic structure of H -bonded di- and tri-peptide are also studied by means of the ASMO-SCF method, in comparison with those obtained by Suard et al. .
TL;DR: In this paper, the nucleation of gold from the vapour phase on sodium chloride is studied as a function of substrate temperature and incidence rate, and the relationship between the increased nucleation density and the enhancement of (100) parallel growth is discussed.
TL;DR: Refractive indices n a, n b and n c of SbSBr have been found to be 2.64, 3.13 and 4.00, respectively, using modified Chaulnes' method.
Abstract: Refractive indices n a , n b and n c of SbSBr have been found to be 2.64, 3.13 and 4.00, respectively, using modified Chaulnes' method. These values can be explained as being caused by the large electronic polarizabilities of sulfur and bromine. Absorption coefficients for the light having electric vectors parallel to the [100], [110] and [001] were obtained. Although SbSBr is paraelectric in the measured temperature range of -60∼190°C, non-linear temperature dependence of absorption coefficients was observed. The results are discussed in comparison with those for SbSI.
TL;DR: In this article, the change in the helical fraction of polyeptide is calculated on applying an external force at the ends of the chain in a helix-coil transition region, where the mean square end-to-end distance of chain has a minimum at the transition region.
Abstract: The change in the helical fraction of polyeptide is calculated on applying an external force at the ends of the chain in the helix-coil transition region. It is shown that when the mean square end-to-end distance of chain has a minimum at the transition region, the helical fraction increases at the helix-side and decreases at the coil-side of the transition region on applying the force. The critical value of the force to make the helical content almost vanish is estimated and the force to make the helical content almost vanish is estimated and the implication of this phenomenon in the mechanical denaturation of polypeptides such as polyglutamic acid and silk fibroin is discussed.
TL;DR: Both spontaneous and evoked GSRs were compared at different phases of the sleep (para-sleep and ortho-sleep) in unrestrained chronic cats and periods of complete silence and/or those of successive evocations appeared alternately.
Abstract: Both spontaneous and evoked GSRs were compared at different phases of the sleep (para-sleep and ortho-sleep) in unrestrained chronic cats. The GSRs were recorded from the forelimb paw pads, using zinc with zinc sulphate electrodes.In 68 percent of 81 cases with 13 cats the number of spontaneous GSRs decreased during the para-sleep phase rather than during ortho-sleep phase, while in 32 percent it increased. The increased cases were characterized by a burst pattern composed of continuous small potentials continuing for 5 to 60 sec.In the ortho-sleep phase, stimulation of peroneal nerve fibers evoked GSRs occasionally, while in the para-sleep phase, periods of complete silence and/or those of successive evocations appeared alternately.
TL;DR: In this article, the separation energy of the n th proton increases monotonically (except for odd even effects) as the neutron number is increased, showing little, if any, discontinuity at magic neutron numbers.
TL;DR: Both the palmar surface of the finger and the skin-drilled forearm were subjected simultaneously to the same variable concentration of NaCl solution for electrode-electrolyte and there were no consistent tendencies in the skin potential levels or changes in the waveform of skin potential reflexes.
Abstract: Both the palmar surface of the finger and the skin-drilled forearm were subjected simultaneously to the same variable concentration of NaCl solution for electrode-electrolyte. There were no consistent tendencies in the skin potential levels, and no changes in the waveform of skin potential reflexes with varying concentration.
TL;DR: In this article, an improved method of measuring the alpha-gamma angular correlation is proposed, which consists of a gridded ionization chamber and a NaI scintillation counter.
01 Jan 1968
TL;DR: In this article, it was shown that the abstract Cauchy problem has a stable difference scheme, and that a perturbation operator and its difference approximation have some suitable properties.
Abstract: This paper is to show, if the abstract Cauchy problem has a stable difference scheme, then the Cauchy problem of a perturbed equation has also a stable difference scheme when a perturbing operator and its difference approximation have some suitable properties. And it will be noted this result is applicable to parabolic differential equations and their lower order terms, when parabolic difference schemes are used as original difference schemes.
TL;DR: The molecular motion of low molecular weight polychlorotrifluroethylene of different molecular weights between 500 and 1300 was investigated by means of broad-line nuclear magnetic resonance measurements as discussed by the authors.
Abstract: The molecular motion of low molecular weight polychlorotrifluroethylene of different molecular weights between 500 and 1300 was investigated by means of broad-line nuclear magnetic resonance measurements. The line width and second moment of the resonant absorption lines were obtained at temperatures from 77 to 300°K. The line narrowing for low molecular weight samples takes place in one step. In samples higher than 900 in molecular weight, however, there appears to be a glass transition process, and the line narrowing tends to occur in three steps. The line narrowing due to local molecular motion becomes observable with increasing molecular weight.