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21.
Teruhiro Kasagi Takanori Tsutaoka Kenichi Hatakeyama 《Journal of the European Ceramic Society》2010,30(2):401-406
Dielectric and electrical properties of Permalloy granular composite materials have been studied considering the application to left-handed meta-materials. Surface oxidized Permalloy particles have high surface electrical resistance; the eddy current effect in the composite structure is suppressed. The electrical conductivity of compacted Permalloy particles increases with increasing temperature and indicates the semiconductive layer formation on the particle. The low frequency ac electrical conductivity of Permalloy composite materials shows a drastic increase in the particle content between 50 and 60 vol.%. Electrical permittivity spectra of Permalloy composites show a non-metallic characteristic and the enhancement of permittivity is observed with increase of Permalloy particle content. 相似文献
22.
23.
Ductile‐to‐brittle transition behavior of low molecular weight polycarbonate under carbon dioxide 下载免费PDF全文
Tomoaki Taguchi Ramu Miike Tomoe Hatakeyama Hiromu Saito 《Polymer Engineering and Science》2018,58(5):683-690
We investigated the stress–strain behavior of low molecular weight polycarbonate for optical disc grade (OD‐PC) under carbon dioxide (CO2) at various pressures, and compared the results with that under ambient pressure at various temperatures. Elongation at break decreased sharply with increased CO2 pressure at around 2 MPa, while the elastic modulus decreased gradually up to 6 MPa. These results indicate that the tensile property changed from ductile to brittle with increased CO2 pressure, although the molecular motion is accelerated due to the plasticization effect of CO2. Such ductile‐to‐brittle transition is similar to that observed under elevated temperatures caused by chain disentanglement due to accelerated molecular motion. Although the changes of tensile properties were similar, the craze structure obtained by the brittle behavior was different, i.e., a filamented‐craze structure was obtained under high‐pressure CO2, while a lace‐like one was obtained under elevated temperatures. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers 相似文献
24.
Yoshiharu Hatakeyama Mitsuo Umetsu Masahiro Minami Satoshi Ohara Seiichi Takami Tadafumi Adschiri 《Journal of Materials Science》2008,43(7):2426-2430
The DNA, which forms a double helical conformation by the highly selective base-pairing rule with the width of 2 nm, is one
of the polymers utilized as a template for nanoparticle assembly. Then, holiday junction structure, where two different DNA
double strands intersect and replace each complement strand, is an important artificial motif for forming two-dimensional
mesh-like DNA morphology. In this study, the two-dimensional sheet with the mesh-like conformation is formed and the growth
of the DNA morphology is controlled by changing the temperature in the formation process. The influence of the cooling procedure
on the formation process of the two-dimensional DNA sheet is observed by atomic force microscope, and the formation of double
strands in the process is traced by absorption spectra. The spectroscopic results demonstrate that the two-dimensional DNA
sheet is strongly dependent on the correlation between the applied cooling process and the melting temperature of double helical
conformation, and that the growth of the two-dimensional DNA sheet can be manipulated by the cooling procedure. Further, we
will show the size control of the DNA sheet by mixing the designed DNA which inhibits the growth of the DNA sheet. 相似文献
25.
We consider how permselectivity as a function of the membrane is related to the cell evolution with an abstract proto-cell
model. We construct an autopoietic proto-cell model having primitive auto-catalytic reaction cycle inside. In this model,
several primitive membrane substances are assumed to be produced from the reaction cycle and the membrane is assumed to have
a permeability to specific chemical species. We show that the permselectivity of the membrane induces the diversification
of the cell volume. We discuss how the diversification of the cells is related to the Darwinian evolution.
This work was presented in part and awarded as Young Author Award at the 13th International Symposium on Artificial Life and
Robotics, Oita, Japan, January 31–February 2, 2008 相似文献
26.
Primbs T Simonich S Schmedding D Wilson G Jaffe D Takami A Kato S Hatakeyama S Kajii Y 《Environmental science & technology》2007,41(10):3551-3558
To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs. 相似文献
27.
Hyoe Hatakeyama Takahiro Marusawa Tatsuko Hatakeyama 《Journal of Materials Science》2011,46(23):7475-7481
Molasses (ML)-based soft-type polyurethane (PU) foams were successfully prepared by controlling evolved heat during chemical reaction. Two kinds of isocyanate, poly(phenylene methylene) polyisocyanate (MDI) and tolylene diisocyanate (TDI), and polypropylene glycol with a long molecular chain length were utilized to control the chemical reaction. The hydroxyl group in ML was used as the reaction site and soft-type PU foams were synthesized at isocyanate (NCO)/hydroxyl group (OH) ratios of 1.05. Mechanical properties of the above foams were controlled by changing the mixing ratio of MDI and TDI. Pore size and distribution were measured by scanning electron microscopy. With increasing thickness of cell wall, compression strength and modulus increased. Thermal properties of PU foams were investigated by differential scanning calorimetry, thermogravimetry, and thermal conductivity measurements. Two-step glass transition temperatures were observed at around ca. ?55 and 80 °C, regardless of kind of isocyanate. The low temperature side glass transition is attributed to the molecular motion of long oxyethylene chains and the high temperature side transition is caused by rigid components including saccharide components. Thermal decomposition of PU foams started from ca. 270 °C. Thermal conductivity of soft-type PU was observed in a range from 0.034 to 0.035 J s?1 m?1 K?1. 相似文献
28.
S. Hatakeyama M. Ohno H. Takahashi R. M. T. Damayanthi C. Otani T. Yasumune T. Ohnishi K. Takasaki S. Koyama 《Journal of Low Temperature Physics》2014,176(3-4):560-565
We designed and fabricated a hard X-ray and gamma-ray TES spectrometer for nuclear materials analysis. The superconducting tin absorber is coupled to an Ir/Au TES by using a gold post to improve the thermal contact between the absorber and the TES. The reported energy resolution is 156 eV FWHM at 59.5 keV and 166 eV FWHM at 122 keV gamma-rays. We performed measurement of a Pu sample and clearly separated the \(^{239}\) Pu (56.828 keV) and the \(^{241}\) Am (59.5 keV) peaks by this TES microcalorimeter which cannot be resolved by the HPGe detector. 相似文献
29.
A low temperature and low pressure bonding process for alumina and 316L austenitic stainless steel has been developed using a titanium/molybdenum laminated interlayer. The intermetallic compounds of Ti3Al (or Ti2/Al) and TiAl were formed at the alumina/titanium interface on bonding at above 1273 K. The activation energy of the layer growth was about 142 kJ mol–1. The construction of Al2O3/Ti/Mo/steel gave the most stable joints. The highest tensile strength was above 60 MPa with a titanium 0.4 to 0.6mm thick/molybdenum 0.4 to 0.5 mm thick interlayer on bonding at 1273 K for 3 h under pressure of 12 MPa. 相似文献
30.
The so-called Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is a possible inhomogeneous superfluid phase in population-imbalanced two-component Fermi gas systems. Here, a novel phase created by a population-imbalance to be called a Fermion supersolid will be proposed. In a Fermi gas with a short-ranged repulsive interaction, a positional order, corresponding to the antiferromagnetic (AFM) one in the electronic systems, may occur, although the ordinary superfluid phase usually suppresses it in population-balanced two component Fermi systems. However, we show that the coexistence between this “AFM” order and the FFLO superfluid with s-wave pairing is rather favored by the population-imbalance. This coexisting phase is the s-wave analog of the coupled AFM and FFLO orders detected in the d-wave paired superconductor CeCoIn5. 相似文献