Search Results - (Author, Cooperation:A. Inoue)

2018-03-06

Cold Spring Harbor Laboratory Press

0890-9369

Biology

2011-09-24

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

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5-Methylcytosine/metabolism ; Animals ; Blastocyst/*metabolism ; Chromatids/metabolism ; Chromosomes, Mammalian/*metabolism ; Cytosine/*analogs & derivatives/metabolism ; *DNA Replication ; DNA-Binding Proteins/*metabolism ; Embryonic Development ; Mice ; Mitosis ; Proto-Oncogene Proteins/*metabolism ; Sister Chromatid Exchange ; Zygote/metabolism

2015-09-01

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

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Medicine

Natural Sciences in General

Physics

Animals ; Axons/*physiology ; Chick Embryo ; Coculture Techniques ; Ganglia, Spinal/*cytology/physiology ; Gene Knockout Techniques ; Glycerophospholipids/analysis/metabolism/*physiology ; Glycolipids/analysis/*physiology ; Mice ; Nerve Growth Factor/pharmacology ; Neuroglia/*physiology ; Nociceptors/*physiology ; Receptor, trkA/metabolism ; Receptor, trkC/metabolism ; Receptors, Cannabinoid/genetics/*physiology ; Spinal Cord/*cytology/*embryology ; Tissue Culture Techniques

2012-11-16

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

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Alleles ; Animals ; Cell Count ; DNA Breaks, Double-Stranded ; DNA Methylation/genetics ; DNA-Binding Proteins/deficiency/genetics/*metabolism ; Embryo, Mammalian/cytology/pathology ; Female ; Gene Expression Regulation/*genetics ; Infertility, Female/pathology ; Male ; Meiosis/*genetics ; Mice ; Mice, Knockout ; Oocytes/cytology/*metabolism/pathology ; Proto-Oncogene Proteins/deficiency/genetics/*metabolism ; Transcriptome

2018-11-09

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-12-04

Cold Spring Harbor Laboratory Press

0890-9369

Biology

1089-7550

AIP Digital Archive

Physics

The preparation condition, microstructure, and morphology of ultrafine Al and AlN particles were examined by a combined technique of nitrogen plasma–aluminum reaction and spray deposition as well as by metallographic techniques. The Al and AlN particles have the morphologies of sphere and hexagonal plate, respectively, and the particle size is 5 to 200 nm for Al and 20 to 120 nm for AlN. The volume ratio of AlN to Al increases continuously with an increase of the mixing gas ratio of nitrogen to argon and the total pressure of nitrogen and reaches about 25% in a nitrogen atmosphere with a pressure of 93 kPa. The composite Al–AlN particles are also observed and have an orientation relationship of (111)Al//(001)AlN, [101¯]Al//[110]AlN, and [12¯1]Al//[11¯0]AlN, in which the lattice misfit is as small as 6.4%, 8.6%, and 8.6%, respectively. The formation of the composite particles is presumed to result from the collision and incorporation of Al particles with the AlN plate adhered to Al particles. The Al and AlN particles produced by the present method are concluded to be small and homogeneous enough to be used as raw materials for the production of nanoscale composites and compositionally gradient materials.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The field dependence of the magnetization at 4.2 and 294 K and the temperature dependence of the spontaneous magnetization for two series of ternary Co-based alloys, namely Co76−xB24Cx and Co88−yByC12 have been measured. The metalloid content in these series ranges from 24 to 44 at.%, and extends almost to the critical concentration for the disappearance of ferromagnetism. The composition dependence of the average magnetic moment at 4.2 K compares well, for low metalloid content, with data for other Co-based materials and also with the theoretical models that predict a linear dependence of the magnetic moment as a function of concentration. The thermal demagnetizing process at low temperatures is presented. The results have been analyzed in terms of Bloch's law and the stiffness constant has been determined. The complete thermal demagnetization, i.e., down to Tc, is presented only for the alloys with a Curie temperature below 300 K. The results show the well known flattening of the M(T) curve as compared with crystalline materials.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The application of reactive sputtering in a mixed gas of argon (Ar) and nitrogen (N2) to Al metal resulted in the formation of compositionally gradient film consisting of Al and AlN phases. By changing the mixing gas ratio of N2 to N2+Ar so as to be 0, 0.05, 0.1, and 0.2 in a total gas pressure of 1 Pa, the resulting phase changes in the order of Al, Al+AlN, AlN+Al, and AlN and the thickness of each phase is 14, 23, 18, and 8 μm, respectively, after sputtering for 3.6, 5.4, 7.2, and 10.8 ks, respectively. The Al concentration along the sample thickness changes from 100% to about 50% with an increase of mixing ratio from 0 to 0.2. The lattice parameters of Al and AlN phases remain constant along the sample thickness. The Knoop hardness and the electrical resistivity increase steeply from 100 to 3900 and from 3×10−8 Ω m to an infinite value, respectively, with the phase transition from Al to AlN through Al+AlN and AlN+Al. The load leading to an exfoliation among the layers was measured to be 16 N. Thus, the sputtered Al-AlN film is concluded to possess functionally gradient characteristics resulting from the compositional and structural gradients.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We have studied the effect of tension and external field on the magnetization process in amorphous positive magnetostrictive Fe-Si-B wires. The radial stress created during the in-rotating water quenching technique of producing these wires causes a radial anisotropy. Using a simple phenomenological model which assumes a continuous distribution for the values of these radial stresses, we fit the observed values of the remanence as a function of the applied longitudinal stress and obtain information about the stress distribution. We also explain in a consistent manner the dependence of the magnetization process on the applied longitudinal stress. On doing so, a value of the saturation magnetostriction constant λs=28×10−6 is obtained for a Fe77.5Si7.5B15 amorphous wire. In the stress dependence of the nucleation field for the Barkhausen jump we observe a minimum. A quantitative explanation for this minimum is given.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We present ac susceptibility, electrical resistivity, and Hall effect measurements for a new series of Al-rich amorphous alloys Al90R10 with R=Y, La, Ce, Nd, Sm, Gd, Tb, Ho, and Er. The electrical resistivity at room temperature is approximately constant and around 70 μΩ cm, and increases with increasing temperature. The ac susceptibility, measured between 4 and 150 K shows that most of the alloys follow a Curie–Weiss behavior with an effective magnetic moment close to that of the pure rare-earth elements. The ordinary Hall coefficient has a negative value around half of the expected using a free electron approach. Due to the magnetic moment carried by the rare-earth elements in these alloys a magnetic contribution to the Hall effect cannot be ruled out although a detailed comparison with the theory is not available at present.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Amorphous alloys with a wide supercooled liquid region (ΔTx) before crystallization were formed in the Fe56Co7Ni7Hf8M2B20 (M=Nb, Ta) alloys by melt spinning. The ΔTx which is a critical factor of glass-forming ability, increases to large values exceeding 90 from 82 K by the addition of 2 at. % M, and the largest ΔTx value is larger by about 10 K than the largest value for recently reported (Fe,Co,Ni)–Zr–M–B alloys. By the addition of the M metals, magnetic properties also changed. Good soft magnetic properties were obtained for the alloys annealed for 300 s at 800 K. The saturation magnetization (Is), coercive force (Hc), and effective permeability (μe) at 1 kHz are, respectively, 0.71 T, 1.0 A/m, and 16 700 for the M=Nb alloy and 0.76 T, 1.0 A/m, and 15 600 for the M=Ta alloy. The finding of the Fe-based amorphous alloys exhibiting simultaneously the wide supercooled liquid region before crystallization and the good soft magnetic properties seem to enable the future development of a new ferromagnetic bulk amorphous alloy. © 1999 American Institute of Physics.

Electronic Resource

1089-7658

AIP Digital Archive

Mathematics

Physics

In the algebraic formulation of quantum theories, a state is often represented by a normal linear functional on some *-algebra @FA of operators on a Hilbert space, i.e., a functional of the form f(X)=Tr TX for some trace class operator X. The question is whether every strongly positive (i.e., positive on positive elements) linear functional is normal. Criteria for this statement to be true are well known in the case where @FA is a *-algebra of bounded operators (C*- or W*-algebra) or a *-algebra of unbounded operators (O*-algebra). Those results are extended to the case where @FA is a (weak) partial *-algebra of closable operators, both for linear functionals and for sesquilinear forms.

Electronic Resource

1089-7658

AIP Digital Archive

Mathematics

Physics

In this paper an unbounded generalization of left Hilbert algebras by partial *-algebras is considered, and the Tomita–Takesaki theory is extended to partial O*-algebras. While such a construction has been considered in previous papers [A. Inoue, Publ. RIMS, Kyoto Univ. 22, 725 (1986); 23, 673 (1987); "Modular Systems for algebras of unbounded operators, preprint, Fukuoka Univ. (1990)], the present one places emphasis on a rich class of unbounded operators, and is more applicable to examples.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The nanoscale crystalline and amorphous phases obtained by partial crystallization of an amorphous phase in rapidly solidified Fe90Nd7−xZrxB3 alloys were found to exhibit rather good hard magnetic properties in the composition range below 3 at. % Zr and good soft magnetic properties in the range above 4 at. % Zr. The hard magnetic alloys consist of nanoscale bcc–Fe and bct–Fe14Nd2B particles surrounded by the remaining amorphous phase, while the soft magnetic alloys are composed of bcc–Fe and remaining amorphous phases. The particle size is measured to be about 20 nm for the bcc–Fe phase and 15 nm for the Fe14Nd2B phase for a the former alloys and about 10 nm for the bcc–Fe phase for the latter alloys. The volume fraction of the remaining amorphous phase is evaluated to be about 20 to 30 at. % and the Nd and Zr contents are much higher than the nominal concentrations for the hard and soft magnetic alloys from the high-resolution TEM images and nanobeam compositional analyses. The remanence (Br), intrinsic coercivity (iHc), and maximum energy product are 1.24 T, 200 kA/m, and 88 kJ/m3, respectively, for the nanocrystalline Fe90Nd5Zr2B3 alloy annealed for 180 s at 1023 K, while the saturation magnetization (Bs), coercivity (Hc), and permeability at 1 kHz are 1.63 T, 16 A/m, and 7000, respectively, for the nanocrystalline Fe90Nd2Zr5B3 alloy annealed for 180 s at 923 K.The high Br and Bs values are presumably due to the magnetic coupling between bcc–Fe particles via the ferromagnetic intergranular amorphous phase and the large iHc for the alloy containing more than 4 at. % Nd is due to the exchange magnetic interaction betweeen Fe14Nd2B particles via ferromagnetic bcc–Fe and amorphous phases. The appearance of the rather good hard and soft magnetic properties for the same alloy series containing the high Fe content is extremely important for future development of manocrystalline hard and soft magnetic materials. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Low-temperature magnetic properties of the Co56−xB32+xC12, x=0, 2, 4, and 4.5 ternary amorphous alloys are investigated by using low-field ac magnetic susceptibility measurement techniques and also a superconducting quantum interference device magnetometer. The ac susceptibility data show that these alloys undergo a paramagnetic to ferromagnetic state transition at cryogenic temperatures. The Curie temperature Tc decreases linearly with decreasing Co content at a rate 31 K per Co at %, suggesting a percolation limit for the disappearence of ferromagnetism at around 50 at % Co. A scaling analysis performed on magnetic isotherms obtained near Tc; even for the sample almost close to the percolation limit, yields critical exponent values consistent with the 3D-Heisenberg model for an ideal ferromagnet. Thus in these Co-based amorphous alloys, long-range order persists to the concentrations almost at the percolation limit and the mean-field theory is found to describe well the paramagnetic to the ferromagnetic state phase transitions.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

We have recently succeeded in producing good soft magnetic properties and high saturation magnetic density (Bs) for nanocrystalline Fe-M-B (M=Zr, Hf, or Nb) ternary alloys prepared by melt spun and sputtered technic. The alloys have the mixed structure consisting of α-Fe particles with 10–20 nm in size embedded in a remaining amorphous phase. The nanocrystalline bcc Fe90Zr7B3, Fe89Hf7B4 and Fe84Nb7B9 alloy ribbons subjected to the optimum annealing exhibit high Bs of 1.5–1.7 T as well as high effective permeability (μe) of 22 000–32 000 at 1 kHz. The soft magnetic properties of the nanocrystalline Fe-M-B alloys were found to be improved by adding small amounts of Cu and by optimizing the chemical composition. The addition of Cu to the alloys decreases the bcc grain size. The excellent soft magnetic properties (high μe of 100 000 at 1 kHz combined with high Bs of 1.53 T) can be achieved in the region where small grain size as well as nearly zero magnetostriction are obtained, which is attained in the compositional range around Fe84Nb3.5Zr3.5B8Cu1. The soft magnetic properties can be further improved by preannealing before crystallization treatment, probably resulting from the decrease in the distribution of the grain size at the crystallized state. Consequently, the μe reaches the maximum value of 120 000 for the nanocrystalline Fe84Nb3.5Zr3.5B8Cu1 alloy. © 1996 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

The structure, soft magnetic properties, magnetostriction, grain size and volume fraction of the residual amorphous phase have been studied for an amorphous Fe91Zr7B2 alloy annealed for periods of 60 s–1080 ks, at temperatures of 823–973 K. The highest permeability (at 1 kHz and 0.4 A/m) 31,000 and smallest coercivity 4.2 A/m are obtained for the sample annealed at 923 K for 60 s, where a small grain size (≈12 nm) and about 35% of the residual amorphous phase are measured. The coercivity of the nanocrystalline alloy varies as the 3rd power of the grain size, corresponding to the case where the magnetically coupled region has a dimensionality between two and three. This slightly low dimensionality is presumed to be due to the alignment of the magnetization in the sample plane. © 1996 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

The microstructure of Fe73.5Si13.5B9Nb3Cu1 soft magnetic material with a nanocrystalline structure has been investigated by atom probe field ion microscopy. In the as-quenched amorphous sample, all the alloying elements were found to distribute homogeneously as an amorphous solid solution. In the annealed sample with the optimum soft magnetic properties, we found that two phases were present. One was Fe-Si solid solution and the other was the B- and Nb-enriched region with less Si content. Although some uncertainty remains regarding Cu, the present result is consistent with an early speculation based on the lattice parameter measurement.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Temperature effects on charge retention characteristics of integrated SrBi2(Ta,Nb)2O9 thin film capacitors were examined in the temperature range of 27–150°C. The decay in remanent polarization at 27°C was linear in logarithmic time from 10−3 to 105 s with a decay rate of 0.24 μC/cm2 per decade. The elevation of storage temperature resulted in an instantaneous decrease in remanent polarization, while the decay rate at elevated temperatures after the instantaneous decrease was as small as that at 27°C. The instantaneous decrease in remanent polarization caused by elevating the temperature was explained by the temperature dependence of spontaneous polarization in the vicinity of the second order transition temperature. The development of asymmetry in the hysteresis loop during high temperature storing indicates that the logarithmic time dependence of the decay in remanent polarization is due to redistribution of space charges rather than polarization reversal. © 1997 American Institute of Physics.

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