91 publications from this institution
An attempt has been made to investigate the microstructure and soft magnetic properties of Fe-Al alloys produced by a rapid solidification technique, with the aim of estimating their aptitude as core elements in rotating machinery. Examinations by optical and transmission electron microscopy revealed that the specimen containing aluminium up to about 23 at. % consists of ductile ferrite, whereas further addition of aluminium gives rise to embrittlement by the formation of an ordered b.c.c. compound. Furthermore, the rapidly solidified alloys exhibited high saturation induction values, more than 1.88 T in the alloys with aluminium content below 10 at.%. For the coercivity behaviour and core loss at 50 Hz, notable improvement was achieved after annealing at elevated temperatures. It was thus concluded that the present alloys have potential for practical use as magnetic core materials in rotating machinery.
Electricity and paper consumptions were estimated quantitatively for the cases where paper documents can be easily converted to electronic ones using combination of Fuji Xerox's multifunctional device of DocuCentre Color 450 and Fuji Xerox's software of DocuCentre Flow Service. For the typical case reduction of electricity and paper consumption as high as 15% and 0.79 t was shown to be attained.
No abstract is provided for this article.
The development of environmentally conscious office equipment at Fuji Xerox is described, taking digital equipment Able1250 and DocuCenter450/550 families as examples. The following are described: (1) power management at standby state; (2) energy saving of electronics circuits; (3) miniaturization of xerographic engine unit; (4) efficient duplex mechanism utilizing digital processing; and (5) reuse of machine parts and recycling of materials.
A new Fe-based bulk glassy alloy with high glass-forming ability, super-high fracture strength, and plasticity is described. The [(Fe0.8Co0.1Ni0.1)0.75B0.2Si0.05]96Nb4 alloy has a super-high strength of over 4000 MPa, the highest yet reported for Fe-based bulk alloys. In compressive failure, a shear band with an angle of 43° relative to the compression direction can be observed by scanning electron microscopy (see Figure).
An exciton-exciton collisional annihilation was studied with the naphthalene-tetracyanobenzene complex crystal by observing and analyzing the fluorescence decay curve; the second-order decay constant was determined to be 3 × 10−13 cm3 sec−1 at 77°K. A new type of inhomogeneous broadening effect was found for the fluorescence from the complex crystal excited in high density and was interpreted to be due to the strong electrostatic interaction between the charge-transfer excitons with large dipole moments.
A glassy phase with glass transition (GT) was formed in a wide B content range of 12‒31 at% for (Co0.75Cr0.125Mo0.125)100-xBx alloys. The appearance of GT at the low metalloid content of 12%B among Co-, Fe- and Ni-based alloys is the first, in contrast to the absence of GT for (Fe0.75Cr0.125Mo0.125)88B12 and (Ni0.75Cr0.125Mo0.125)88B12 alloys. The Co-based 12%B glassy alloy crystallized through unique three stages, i.e., glass (G) → [G + hcp + fcc] → [G + fcc] → [fcc + M23B6]. The appearance of GT is due to the necessity of long-range rearrangement of constituent elements for the simultaneous precipitation of hcp and fcc phases from glassy phase. The glass transition temperature, crystallization temperature, Vickers hardness (Hv) and Young's modulus for the Co-based glassy alloys increase linearly with increasing B content and reach 904 K, 946 K, 1566 and 188 GPa, respectively, at 31%B. The good bending plasticity is retained up to 29%B. The crystallization of the 27‒29%B alloy occurs through G → [G + M23B6] → [M23B6 + M2B] and the ultrahigh Hv above 2000 is attained for the metastable [G + M23B6] phase state. The glassy alloy rod with a diameter of 1 mm was prepared for the 27%B alloy and exhibited ultrahigh yield strength of 4700 MPa, plastic strain of 1% and high oxidation resistance up to about 1200 K. The Co-based bulk glassy alloy with simultaneously high strength, ultrahigh hardness and high oxidation resistance, is promising for the future high hardness and heat-resistance materials.
Viscoelastic behaviors of a Zr‐based glassy alloy in the glass transition region were investigated with uni‐axial compression tests. The transition between the linear and the nonlinear viscoelasticity was observed just as it was observed in other glassy materials. The transition is considered to be due to a structural change in the glassy structure. Using the relationship taken from experimental results between the steady‐state flow stress and their relaxation time at various temperatures, we make the steady‐state flow stress, which is named fictive stress, stand for the flow structure during deformation. Based on the hypothesis of the stress‐induced structure change and the concept of the fictive stress, we succeeded in demonstrating various characteristic viscoelastic behaviors. The model calculations agreed fairly well with the experimental results. The condition under which the transition occurs and the mechanism of the transition itself in various deformations of a Zr‐based glassy alloy were demonstrated by this model calculation.
Comparison of spin sublevel population rates in pyrimidine and 5-methylpyrimidine suggests that the vibronic perturbation of 3B2 and/or 3A1 ππ* states by a higher-lying 3A2nπ* state plays an important role in S1 → T1 intersystem crossing of pyrimidine. The result also implies that the n+π*—n−π* splitting in pyrimidine is significantly smaller than the corresponding gap in pyrazine. The appearance of the 0.0 band in the τx spectrum indicates that the triplets state symmetry is lower tha C2v.
