Crystallization behaviours around the glass transition temperature in an amorphous Fe–Nb–B alloy

Crystallization behaviours around the glass transition temperature in an amorphous Fe₇₀Nb₁₀B₂₀ alloy were investigated by means of transmission electron microscopy. Dense bcc-Fe nanocrystals initially appeared as the primary phase, followed by the dense formation of the (Fe,Nb)₂₃B₆ nanocrystalline phase. The bcc-Fe nanocrystals were formed even by annealing at a temperature that is 38 K lower than the glass transition temperature. A difference of the low temperature behaviours between the present conventional amorphous alloy and a bulk metallic glass was discussed.     

An approach for organizing knowledge according to terminology and representing it visually

We describe a term relation frequency (TRF) method for finding comprehensive documents in a rapidly growing academic discipline. The method enables us to organize knowledge into a single document based on terminology. The method is based on the classification of documents into comprehensive, central, peripheral, and independent classes according to the commonality and exclusiveness of terminology. Being able to find the documents quickly is helpful for our understanding of the discipline. Multiple-meaning technical terms such as "coordination" play a key role in rapidly growing academic disciplines such as coordination science. Visual representation of the multiple-meaning terms helps us to identify quickly and easily how the terms are used. With TRF and visualization methods, we can identify documents that explain a technical term comprehensively. We can also identify a change in the subject of a discipline according to when the comprehensive documents are written. We show that the observed change matches our understanding of the topic of the field "coordination science." The methods discussed here are promising to help us quickly understand and advance research in rapidly growing academic disciplines such as coordination science.     

Corrosion evaluation of Au-Cu-Pd ternary alloys

The corrosion resistivity of single-phase Au-Cu-11 at% Pd alloys was evaluated by using a parameterQ which represented the total amount of anodic reaction in a potentiostatic polarization test. The result was compared with those for binary Au-Cu, ternary Au-Cu-11 at % Ag and some commercial alloys. The validity of usingQ as a corrosion parameter was confirmed by the good agreement between the analysed and calculated values of copper ion dissolved into the test solution. By replacing a part of the copper in Au-Cu alloys with palladium the corrosion resistivity can be greatly improved, but silver has no such significant effect. The value ofQ decreased by both treatments of homogenization and grain refinement of the alloy. One of the advantages of the alloy having a single-phase structure is that inhomogeneity in the distribution of the constituents is small even in the as-cast state, which results in a small galvanic effect.     

High Field ESR System and Its Application to the Study of Quantum Spin Systems

Developments of the high field ESR system in Kobe University is presented. Using Gunn oscillators and backward traveling oscillators (BWO), we can cover the frequency region from 30 to 1183.6 GHz with the use of InSb detector. Pulsed magnetic field up to 30 T is available and we are now trying to extend the field up to 40 T. Temperature range is from 1.8 to 300 K. Using this system, we studied S=1/2 ladder like system Cu₂(C₅H₁₂N₂)₂Cl₄, and found a new magnetic transition at 10.1 T at 1.8 K. The temperature dependence of ESR in Cu₂(C₅H₁₂N₂)₂CI₄ shows g-shift below 8 K which corresponds to the maximum of the magnetic susceptibility. The g-shift below 8 K suggests the increase of the quantum fluctuation in the system, and the role of the quantum fluctuation in Cu₂(C₅H₁₂N₂)₂CI₄ is discussed.     

Kinetic study on free radical polymerization of alkyl acylamidoacrylates by pulsed laser polymerization using nitrogen laser

Radical polymerization of captodatively substituted alkyl acylamidoacrylates was studied by pulsed laser polymerization using a N₂ laser. Propagation rate coefficient of the acrylates was varied with solvents used in spite of a radical mechanism, but little varied with methyl, n-propyl, and isopropyl substituents on the acrylates. Arrhenius parameters for the propagation indicated that a solvent affected mostly on a frequency factor rather than a activation energy. In addition, it was suggested that these captodatively substituted propagating radicals were thermodynamically persistent but kinetically active in propagation, which resulted in rather smooth propagation in spite of bulky 1,1-disubstituted olefins. The mechanism of the polymerizations was discussed in detail on the basis of the kinetic studies and ESR spectroscopy.     

Formulation of a standard deviate observer by a nonlinear optimization technique

A standard deviate observer (SDO) has been formulated that can predict the average color mismatches of metameric color pairs by 20 Stiles' observers. A nonlinear optimization technique, rather than a statistical analysis, has been employed to derive it. The colorimetric characteristics of the present SDO are compared with those of SDOs previously proposed.