Showing papers by "Tokyo Institute of Technology published in 1975"
TL;DR: In this article, a poly-p-benzamide of high molecular weight (ηinh = ∼ in H2SO4) was obtained by direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides.
Abstract: Poly-p-benzamide of high molecular weight (ηinh = ∼ in H2SO4) was obtained by the direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides. Molecular weight of polymer varied with the amount of these salts, showing maximum values at the concentration of about 4 wt-% of LiCl or about 8 wt-% of CaCl2 in the reaction mixture. The reaction temperature at around 80°C gave a polymer of the highest viscosity. The polycondensation reaction was also affected by monomer concentration, solvents, and tertiary amines like pyridine. Similarly, aromatic polyamides with high molecular weight (ηinh values up to 1.34 in H2SO4) were prepared from isophthalic acid and aromatic diamines, whereas terephthalic acid gave only low-viscosity polymers.
529 citations
31 Dec 1975
TL;DR: In this paper, a monograph devoted to the spectral theory of the Sturm-Liouville operator and the Dirac system has been published, with a focus on the spectral properties of the spectral theories of differential operators.
Abstract: This monograph is devoted to the spectral theory of the Sturm- Liouville operator and to the spectral theory of the Dirac system In addition, some results are given for nth order ordinary differential operators Those parts of this book which concern nth order operators can serve as simply an introduction to this domain, which at the present time has already had time to become very broad For the convenience of the reader who is not familiar with abstract spectral theory, the authors have inserted a chapter (Chapter 13) in which they discuss this theory, concisely and in the main without proofs, and indicate various connections with the spectral theory of differential operators
406 citations
TL;DR: In this paper, thermal analysis and infrared spectroscopy of polyacetylene was used to investigate cis-trans isomerization, hydrogen migration accompanied with crosslinking reaction, and thermal decomposition.
Abstract: Thermal cis-trans isomerization and decomposition of polyacetylene film prepared with a Ti(OC4H9)4–Al(C2H5)3 (Al/Ti = 4) system were investigated under inert gas or in vacuum by means of thermal analysis and infrared spectroscopy. Thermograms of differential thermal analysis of cis-polyacetylene revealed the existence of two exothermic peaks at 145 and 325°C and one endothermic peak at 420°C which were assigned to cis-trans isomerization, hydrogen migration accompanied with crosslinking reaction, and thermal decomposition, respectively. The isomerization was followed by infrared spectroscopy over the temperature range 75–115°C. The reaction did not obey simple kinetics. The apparent activation energy for the cis-trans isomerization was 17.0 kcal/mole for the polymer containing 88% cis configuration and increased with increasing trans content up to 38.8 kcal/mole for 80% trans content.
280 citations
TL;DR: The functional visual field defined in terms of a discrimination task of a target presented peripherally among ambiguous background patterns was investigated for various foveal loads which were to be recognized at the central retina.
Abstract: The functional visual field defined in terms of a discrimination task of a target presented peripherally among ambiguous background patterns was investigated for various foveal loads which were to be recognized at the central retina. Foveal loads were numbers, letters, place names, traffic signs, and other figures to simulate commonplace situations for foveal information processing, and grouped into three in order of recognition difficulty based on daily experience. Boundaries of the functional visual field were obtained for simple fixation and for certain foveal loads. Comparison of these boundaries clearly showed shrinkage of the functional visual field size with the foveal loads of greater recognition difficulty.
233 citations
TL;DR: In this article, it has been found that in NH 4 LiSO 4 another transition point 186.5°C exists in addition to the already known one 10°C and this substance is ferroelectric between these two transition points.
Abstract: It has been found that in NH 4 LiSO 4 another transition point 186.5°C exists in addition to the already known one 10°C and this substance is ferroelectric between these two transition points. Anomalies of dielectric constant at the transition points are very small as compared with those of proper ferroelectrics. The Curie-Weiss law holds within a narrow temperature range in the phase above the upper transition, where the Curie constant has a very small value of 5.6 K. Moreover the spontaneous polarization shows a curious increase with lowering temperature. Thus NH 4 LiSO 4 can be said to be one of improper ferroelectrics.
126 citations
TL;DR: In this paper, a linear relationship between the reduction half-wave potential of a transition metal complex and its free ligand is predicted, when it is assumed that the electron added to the complex in electrochemical reduction occupies a molecular orbital mainly composed of a ligand π*-orbital.
120 citations
TL;DR: Growth kinetics of multiply twinned particles (MTP's) of Ag and Au formed by vacuum deposition on MgO and MoS 2 were studied by in-situ electron microscopy as mentioned in this paper.
114 citations
TL;DR: In this article, a series of dynamic cyclic shear tests under undrained conditions were conducted to determine the conditions to induce liquefaction of saturated sands, using a ring torsion apparatus to apply cyclic stresses under nearly plane strain conditions.
107 citations
TL;DR: In this paper, the amounts of both the acidic and basic sites of a series of SnO2-V2O5 catalysts with different compositions were measured by studying the adsorption of the basic and acidic molecules in the gas phase, using both the static and pulse methods.
106 citations
TL;DR: The biological activity profile of the biologically generated 24,25-dihydroxyvitamin D3 is identical to that of 24R,25,dihYDroxyv vitamin D3 and not that of 25-hydroxyv Vitamin D3, which supports the conclusion that the natural compound is 24R.
101 citations
TL;DR: The phase equilibria in the FeFe2O3Y 2O3 system have been established at 1200°C and the standard free energies of formation of yttria, hematite, magnetite, wustite, metallic iron, yttrium-iron perovskite, and a new phase YFe 2O4 belonging to a rhombohedral crystal system were determined in this article.
TL;DR: In this article, the acidity and basicity of two series of catalysts, SnO2MoO3, and SnO 2 ǫP2O5, were investigated, in the presence of an excess of air.
TL;DR: In this article, the authors studied polyethylene over several transition-metal exchanged Y zeolites at near room temperatures and concluded that the active sites on NiY and RhY for the ethylene dimerization were zero-valent Ni and Rh which were dispersed highly in zeolite framework.
01 Jan 1975
TL;DR: In this paper, the acidity of pure Bi 2 O 3 is far lower than that of MoO 3 Bi 2 O3 ǫP 2 O 5, and with an increase in the Bi O 3 content, the acid acidity rapidly increases at first, passes through a maximum at the Bi Mo atomic ratio of 1-2, and then decreases.
TL;DR: In this article, the standard rate constant decreases as the number of the coordinated 2,2′-bipyridine decreases and is interpreted on the basis of the extension of ligand π-orbitals.
TL;DR: In the strong-coupling limit, the polaron ground state energy has been known to be proportional to α 2, α being the electron-phonon coupling constant as mentioned in this paper.
Abstract: In the strong-coupling limit, the polaron ground state energy has been known to be proportional to α 2 , α being the electron-phonon coupling constant. The coefficient of proportionality is found by numerical calculation to be 0.108513 in an appropriate unit. Pekar's variational function is found to give an excellent approximate solution; the energy differs by less than 0.01%, and the error in wave function is less than 1% where the value of the wave function is appreciable.
TL;DR: Several aryl(dipyridyl)nickel halide complexes have been obtained from diethyl(diphrydyl)Nickel and o-chlorophenyl halides and were characterized by elemental analyses, NMR spectroscopy and chemical reactions as mentioned in this paper.
TL;DR: Using the subclass of CF languages defined over paired alphabets, this work proves a refinement of the well-known Chomsky—Schutzenberger Theorem, and also proves that the decision procedure for parenthesis Grammars can be extended to a broader class of CF grammars.
Abstract: We extend the notion of regular sets of strings to those of trees and of forests in a unified mathematical approach, and investigate their properties. Then by taking certain one-dimensional expressions of these objects, we come to an interesting subclass of CF languages defined over paired alphabets. They are shown to form a Boolean algebra with the Dyck set as the universe, and to play an important role in the whole class of CF languages. In particular, using the subclass we prove a refinement of the well-known Chomsky—Schutzenberger Theorem, and also prove that the decision procedure for parenthesis grammars can be extended to a broader class of CF grammars.
TL;DR: In this article, an integrated twin-guide (ITG) laser with an active waveguide and an external waveguide for the light output is proposed as an integrated-optics laser or as a new semiconductor laser, and its properties are investigated theoretically and experimentally.
Abstract: An integrated twin-guide (ITG) laser which has an active waveguide for laser oscillation and an external waveguide for the light output is proposed as an integrated-optics laser or as a new semiconductor laser, and its properties are investigated theoretically and experimentally. ITG lasers were constructed in the form of an AlGaAs multiheterostructure, and their preliminary characteristics were obtained with both optical pumping and current injection at room temperature. The end mirrors of the active waveguide were fabricated by a back-sputtering method. The axial mode selectivity was predicted by the analysis and observed experimentally.
TL;DR: The magnetic moments in the fully occupied layers have been determined, which are ferromagnetic aligned and point along the c-axis with an average moment value of 2.65μB as discussed by the authors.
TL;DR: In this paper, the ESR and the electronic spectra of cupric ions introduced on silica gel by cation exchange between surface hydroxyl groups of silica and tetrammine cupric ion were investigated.
TL;DR: It is suggested that acid mucopolysaccharide isolated from rat liver cell coats is added to growing cultures at concentrations of 50–100 μg/ml and may play an important part in the regulation of cellular proliferation.
TL;DR: Inhibition of cleavage by colchicine was examined by microinjecting colchichine solution into one of the blastomeres of a sea urchin egg at the two‐cell stage and cleavage occurred in spite of the destruction of the mitotic apparatus if the microinjection was made after the critical point.
Abstract: Inhibition of cleavage by colchicine was examined by microinjecting colchicine solution into one of the blastomeres of a sea urchin egg at the two-cell stage. Cleavage was inhibited if the microinjection was made before a critical point prior to the cleavage, whereas cleavage occurred in spite of the destruction of the mitotic apparatus if the microinjection was made after the critical point. The critical point was 10 min before the mid-stage of the cleavage in Clypeaster japonicus and 8 min before the mid-stage in Temnopleurus toreumaticus at 20 ± 1°C, corresponding to the beginning of anaphase. The threshold for the cleavage inhibition of colchicine was estimated to be 3 × 10−5 M to 3 × 10−6 M in final concentration in the cell.
TL;DR: In this article, synthesis and radical ring-opening polymerization of spiro o-carbonates (I-IV) was investigated, and the infrared and NMR spectra indicated that the polymers were alternate copolymers of either and carbonate containing double bonds.
Abstract: Syntheses and radical ring-opening polymerization of spiro o-carbonates(I-IV) were investigated.
These polymers were yellow powders and soluble in common organic solvents. The infrared and NMR spectra indicated that the polymers were alternate copolymers of either and carbonate containing double bonds. The polymerization mechanism is discussed.
TL;DR: In this article, the authors propose a method to solve the problem of "uniformity" and "uncertainty" in the context of health care, and propose a solution.
Abstract: §
TL;DR: In this paper, the authors verified the presence of oxygen stability range in ternary oxides for molybdenum(IV) perovskites, and the widths of stability range were determined of BaMoO 3, SrMoO 2, and CaMoO 4.
TL;DR: In this paper, it was shown that the condition of having a nonempty core is sufficient for an ann-person simple majority game with ordinal preferences to have a non-empty core.
Abstract: Michael Dummett andRobin Farquharson [1961] provided a sufficient condition for ann-person simple majority game with ordinal preferences to have a nonempty core. In the present paper we generalize this result to an arbitrary proper simple game. It is proved that their condition is also sufficient for this game to have a nonempty core. Our proof of this theorem is much simpler than the proof given byDummett andFarquharson. Finally some applications of the theorem are presented.