We have reported the fabrication of MgO core/SnO_2 shell nanowires, by a two-step evaporation process. Thermal annealing induced changes in morphology, in which the nanowire surface became rough by the agglomeration of SnO_2 shell layers and its crystallinity was enhanced. It was found that three fundamental modes (475, 634, 772 cm^{-1}) and an infrared (IR)-active mode (682 cm^{-1}) of rutile SnO_2 appeared in the Raman spectrum of MgO core/SnO_2 shell nanowires. By thermal annealing, the relative intensity of the A_{2u} to the A_{1g} line was reduced, presumably due to the disorder or size effects.
Production of indium oxide (In_2O_3) whiskers at a very low temperature of 650°C was reported. The synthetic route was comprised of a thermal heating process of a mixture of In and Mg powders. We have investigated the structural properties of the as-synthesized nanowires by using X-ray diffraction and scanning electron microscopy. The product consisted of one-dimensional nanowires, with a crystalline cubic structure of In_2O_3. The photoluminescence measurement with the Gaussian fitting exhibited visible light emission bands centered at 2.1 eV and 2.8 eV. The peaks of the Raman spectrum were indexed to the modes being associated with cubic In_2O_3.
During compression molding of glass fiber reinforced plastic composites, annealing and quenching experiment is conducted by changing pre-heating and cooling method. As results, major cause of unevenness that affects waviness profile (winding) is the shrinkage of matrix during holding and cooling process. Waviness profile of the surface on molding in glass fiber reinforced plastic composites will be lower when holding pressure load is higher, mold temperature is lower during demolding, and cooling rate is slower. In addition, surface roughness of moldings is depending on holding pressure load compared with mold temperature. According to molding condition of glass fiber reinforced plastic composites, waviness profile of surface can be quantitatively estimated using the proposed equation.
We have developed an atmospheric pressure plasma apparatus of remote dielectric barrier discharge (RDBD) applicable for a large area. We have systematically studied the characteristics of medium frequency (MF, 40 kHz) and radio frequency (RF, 13.56 MHz) discharge using an optical emission spectroscope. Nitrogen (N₂) and argon (Ar) gases were used in the MF and RF discharge excitation, respectively, in a mixture with clean dry air (CDA). The peak of oxygen radical (O*₂) appears at 259.3 nm when the RDBD is employed. Furthermore, intensive peaks are observed at gas ratios of N₂:CDA=100:1 in MF excitation and at gas ratios of Ar:CDA=70:0.5 in RF discharge excitation. On the other hand, the contact angle shows about 5° in PET samples after the RDBD treatment using the RF and MF discharge excitation. Surface analyses of polyethylene terephthalate (PET) samples were carried out using an atomic force microscope and X-ray photoelectron spectroscope.
The interfacial bonding of silicone-coated stents was characterized by field emission scanning electron microscopy and anodic potentiodynamic polarization tests. The coaxial in-lens secondary electron imaging revealed partial bonding between silicon rubber and nitinol alloy strips in both primer-treatment and plasma-treatment cases. Several strands between the polymer and stent substrate were observed in both cases and it seems that the bonding strength is the same. However, potentiodynamic polarization tests have shown that the corrosion rates of the plasma-treated nitinol stents were less than half of that of the primer-treated stents, indicating higher corrosion resistance. This enhanced corrosion resistance may be attributed to the modification of the physical properties of the surface of the stents by plasma treatments, making the oxide layer more effective than that of the primer-treated stents.
This study reports the production of magnesium oxide (MgO) whiskers on silicon (Si) substrates by the thermal heating of MgB_2 powders. We investigated the structural properties of the as-synthesized whiskers by using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and scanning electron microscopy. The product consisted of one-dimensional whiskers with a square cross-section. The whiskers had a single-crystalline cubic structure of MgO. The photoluminescence measurement with the Gaussian fitting exhibited visible light emission bands centered at 2.39 eV and 2.91 eV. We proposed the growth of MgO whiskers to follow the vapor-solid mechanism.
We synthesized SiO_x nanowires with diameters of 30-140 nm, for the first time by the simple heating of the Mo-coated Si substrates. X-ray diffraction, selected area electron diffraction, and energy-dispersive X-ray spectroscopy indicated that the nanowires were in an amorphous state, comprising Si and O only. Fitting the photoluminescence spectrum with Gaussian functions revealed that the nanowires exhibited significant photoluminescence intensities near blue and green light regions. We extensively discussed the possible growth mechanism of SiO_x nanowires.
We report the production of AlN nanowires by the thermal heating method, for exploring their photoluminescence properties. The room-temperature photoluminescence properties were investigated with different annealing environment. While broad emissions with peaks at around 2.45 and 2.95 eV were obtained from both unannealed and annealed samples, the additional 2.1 eV peak was found from the annealed samples. We have suggested the possible emission mechanisms based on the assumption that both 2.45 eV peak and 2.1 eV peak are ascribed to the nitrogen vacancies. Annealing in N_2 environment exhibited lower intensities of 2.45 eV peak and 2.1 eV peak in comparison to those in Ar environment, presumably due to the suppression of nitrogen vacancies.
A variable-focus fluid lens controlled by an electromagnetic actuator and its characteristics are presented in this paper. The repulsive force between an NdFeB magnet and a solenoid through electromagnetic induction causes deflections in the elastomeric membranes integrated in the lens resulting in a focal-length change. The controllability of the focal length of the fabricated lens with an aperture size of 2 mm was approximately from infinity to 15 mm (with input current of 100 mA). The actuator including the solenoid was carefully designed to avoid thermal crosstalk of the lens fluid and magnet from the electromagnetic induction of the solenoid. The settling time to form a convex shape of the lens membrane was approximately 2.5 ms at an input current of 20 mA.
Spatial solitons were investigated in periodically poled KTiOPO_4 under conditions of second harmonic generation and many new features associated with soliton generation in quasi-phase-matched samples were observed. The effects on the second harmonic generation tuning curves of the beam narrowing mechanisms responsible for soliton generation were found to be dramatic. It was demonstrated experimentally that the mutual collapse of the fundamental and harmonic beams is a complex phenomenon.
The ovine skeletal-muscle-specific calpain gene (p94), which is known also as the n-calpain or calpain 3 gene (CAPN3), was screened with primers. Selection of the PCR primers was based on the ovine cDNA sequence (GenBank accession No. AF087570). After sequence alignment between the ovine and human (AY902237) genes, exon and intron boundaries were determined. Polymorphisms were observed in the intron region for the CAPN31112 and CAPN31213 segments, and the sequences for these segments were submitted to the GenBank (AF309635 and AY102617, respectively). Body weight was recorded at birth, weaning and post-weaning. Calpain 3 genotypes of the CAPN31112 segment were associated with birth weight (P < 0.01), and a dominant gene effect was observed. Breeding group, birth type, and rearing type were significantly associated with weight traits. Allele frequencies were similar in purebred and crossbred animals.
The ovine skeletal-muscle-specific calpain gene (p94), which is known also as the n-calpain or calpain 3 gene (CAPN3), was screened with primers. Selection of the PCR primers was based on the ovine cDNA sequence (GenBank accession No. AF087570). After sequence alignment between the ovine and human (AY902237) genes, exon and intron boundaries were determined. Polymorphisms were observed in the intron region for the CAPN31112 and CAPN31213 segments, and the sequences for these segments were submitted to the GenBank (AF309635 and AY102617, respectively). Body weight was recorded at birth, weaning and post-weaning. Calpain 3 genotypes of the CAPN31112 segment were associated with birth weight (P < 0.01), and a dominant gene effect was observed. Breeding group, birth type, and rearing type were significantly associated with weight traits. Allele frequencies were similar in purebred and crossbred animals.
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