We have studied the magneto-transport of magnetite (Fe3O4) nanoparticles (MNPs) between Au nanogap electrodes (ANGEs) on surface-oxidized Si substrate. The MNP sizes are approximately 40nm and the ...100nm thick magnetite thin film (which is formed of the MNP aggregation) was prepared between and around the ANGEs by use of the RF reactive magnetron sputtering method. The distance between the ANGEs and the bridge width of the ANGEs are approximately 50nm and 1.5μm, respectively. The ANGEs were produced by the tilted-angle-deposition method. The optical microscope, scanning electron microscope and atomic force microscope were used to observe the sample surface structure and morphology. To investigate the crystal structure and crystallinity of the MNPs, the X-ray diffraction measurement was performed. The electrical resistance and magneto-resistance ratio of the MNPs between the ANGEs were measured as a function of temperature. The magneto-transport mechanism is discussed on the basis of the spin dependent transport.
► Between Au nanogap electrodes, magnetite nanoparticle aggregation was prepared. ► Magnetite nanoparticle aggregation was produced by the RF magnetron sputtering method. ► Resistivity and magnetoresistance of magnetite nanoparticle aggregation were measured. ► We propose the tunneling magneto-resistance model due to amorphous-like grain boundaries. ► The model explains temperature dependence on resistivity and magneto-resistance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Redox‐controllable molecular switches composed of two interlocking rings are incorporated here into Langmuir films starting from two different redox states. The morphologies of the resulting ...monolayers and their current–voltage characteristics are then investigated. These switches are considered to be ideal candidates for the fabrication of molecule‐based electronic devices.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Yb3+ doped GdPO4 (GdPO4:Yb3+) nanoparticles are prepared in glycol solvent by autoclave treatment at 230 °C for 120 min. According to X-ray diffraction (XRD) patterns, the sample prepared in ethylene ...glycol is monazite-type GdPO4:Yb3+ without crystal water, while the sample prepared in 1,4-butanediol is rhabdophane-type GdPO4:Yb3+ with crystal water. The former shows more intense near infrared photoluminescence due to the f-f transition of Yb3+ in comparison with the latter. These results indicate that quenching of Yb3+ emission is attributed to energy dissipation due to the O-H vibration of crystal water. When the samples are prepared in ethylene glycol by autoclave treatment at 230 °C for different aging time, the crystallization degree estimated from integrated intensities of XRD peaks increases with increasing aging time. At the same time, the Yb3+ emission becomes strong. We found out that the photoluminescence intensity is linearly related with the crystallization degree.
Glycerophospholipids are main components of cellular membranes and have numerous structural and functional roles to regulate cellular functions. Polyunsaturated fatty acids, such as arachidonic acid ...and eicosapentaenoic acid, are mainly located at the sn-2, but not the sn-1 position of glycerophospholipids in an asymmetrical manner and the fatty acid compositions at both the sn-1 and sn-2 positions differ in various cell types and tissues. Asymmetry and diversity of membrane glycerophospholipids are generated in the remodelling pathway (Lands' cycle), which are conducted by the concerted actions of phospholipases A2 (PLA2s) and lysophospholipid acyltransferases (LPLATs). The Lands' cycle was first reported in the 1950s. While PLA2s have been well characterized, little is known about the LPLATs. Recently, several laboratories, including ours, isolated LPLATs that function in the Lands' cycle from the 1-acylglycerol-3-phosphate O-acyltransferase family and the membrane bound O-acyltransferases family. In this review, we summarize recent studies on cloning and characterization of LPLATs that contribute to membrane asymmetry and diversity.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The normal impact between a golf ball and a rigid steel target was studied to examine ball deformation and the contact force during the impact. Using high-speed video images, the normal and ...tangential compression ratios of the ball were measured to analyze the ball deformation quantitatively. In addition, the inbound and rebound ball velocities, contact time, and coefficient of restitution were determined as basic parameters of the impact. As the inbound ball velocity increased, the maximum normal compression ratio increased while the maximum tangential compression ratio, contact time and coefficient of restitution decreased. The ball center displacements during the impact were measured to determine the ball center velocity and acceleration, and the contact force was calculated by the product of the mass and acceleration. The contact force increased almost linearly with the inbound ball velocity, and its relationship agreed well quantitatively with the results from a load-cell, and also agreed well qualitatively with Hertz contact theory.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ