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排序方式: 共有996条查询结果,搜索用时 15 毫秒
1.
Keita Ikeue Shingo Ando Tomohiro Mitsuyama Yusuke Ohta Keishi Arayama Akiko Tsutsumi Masato Machida 《Topics in Catalysis》2008,47(3-4):175-180
Lanthanide-based oxysulfides and sulfide, LnTaO3.5S0.5, Ln10OS14 (Ln = La, Pr, Nd, Sm) and La4In5S13, were successively synthesized by sulfurization in a flowing H2S. The sulfurization decreased the band-gap energies from >4 eV to <3eV, because of the formation of occupied S3p orbitals
on the top of valence band. In accordance with the small band gap, the H2 evolution from a 0.01 M Na2S and 0.01 M Na2SO3 solution system was observed under irradiation of light up to >500 nm. The rate of H2 evolution under light irradiation of >500 nm increased in the order of Ni/LaTaO3.5S0.5 < Ru/La10OS14 < Pt/La4In5S13. 相似文献
2.
Yujiro Watanabe Yusuke Moriyoshi Yasushi Suetsugu Toshiyuki Ikoma Takeshi Kasama Tadashi Hashimoto Hirohisa Yamada Junzo Tanaka 《Journal of the American Ceramic Society》2004,87(7):1395-1397
Type-A zeolite evenly covered with hydroxyapatite thin layers was prepared using hydrothermal treatment at 120°C for 8 h under autogenous pressure. The hydroxyapatite needlelike nanocrystals, 100–200 nm in diameter and 30 nm in thickness, were grown under the reaction between discharged Ca2+ ions from type-A zeolite and PO4 3− ions in (NH4 )3 PO4 solution. The preferential orientations of the c -axis of hydroxyapatite crystals perpendicular to a zeolite surface were observed using transmission electron microscopy. The crystal structure of type-A zeolite was not destroyed under the reaction, but the surface morphology was changed only with complete covering of scaly hydroxyapatite particles. 相似文献
3.
Ca
x
Ba1−x
TiO3 (CBT) fine particles doped with red luminescence center of Pr3+ ions (Pr: CBT) were successfully synthesized by salt assisted spray pyrolysis (SASP) process. Scanning electronic microscope
(SEM) and laser scattering analysis demonstrate that salt can be removed from the surface of particles by washing with Milli-Q
water and the particles can be further separated by ball-milling to get well-dispersed Pr3+ ions doped CBT fine particles. The luminescence properties, such as photoluminescence (PL) and mechanoluminescence (ML),
of as-synthesized Pr: CBT particles were investigated. For Pr: CBT fine particles with different Ca molar ratios, all the
samples show one emission at 612 nm, with increasing Ca molar ratio, PL intensity of Pr: CBT fine particles become stronger
and stronger. When pressure was loaded on the Pr: CBT pellet, mechanoluminescence(ML) emission was measured. The results show
that the ML intensity is proportional to the applied pressure. 相似文献
4.
Nobuaki Kojima Yusuke Sugiura Masafumi Yamaguchi 《Solar Energy Materials & Solar Cells》2006,90(18-19):3394-3398
C60/amorphous carbon superlattice structures were fabricated by shutter-controlled molecular beam deposition. The periodic structure of resulted films was confirmed by X-ray diffraction measurements. From the UV–vis reflectance/transmittance measurements, the energy shift of absorption edge was observed in the superlattice structures as a function of their well width. The carbon-based superlattice structure is the useful technique to control the band gap energy of carbon materials. 相似文献
5.
Muto S Tatsumi K Puetter RC Yoshida T Yamamoto Y Sasano Y 《Journal of electron microscopy》2006,55(4):225-230
We applied Pixon deconvolution as introduced in Part I to several practical, examples of low signal-to-noise ratio (SNR), electron energy-loss spectra with a goal toward restoring their fine spectral features and/or improving the energy resolution. We demonstrate that by directly fitting the two-dimensional spectral data recorded on the CCD; the method enables us to reveal fine spectral structures. Consequently, Pixon reconstruction extends the ability to probe electronic states in very spatially localized areas, a capability currently unique to our method. 相似文献
6.
Umemura K Noguchi Y Ichinose T Hirose Y Mayama S 《Journal of nanoscience and nanotechnology》2010,10(8):5220-5224
We investigated the morphology and physical-chemical properties of baked and unbaked nanoporous frustules. Scanning electron microscopy (SEM) observations showed that the nanoporous structures of frustules unchanged at 400 degrees C even after baking for 6 h. During baking at 800 degrees C, the frustule structures changed dramatically. On the other hand, Fourier transform infrared spectroscopy (FTIR) of bulk frustule samples indicated that physical-chemical properties of the frustules had clearly changed after baking at not only 800 degrees C but also 400 degrees C. These results showed that the reconstruction of the structures had occurred inside the frustules, even though the morphology of the frustules had not apparently changed at 400 degrees C. In order to characterize the exact shape of the frustules, living diatom cells were grown on a functionalized mica surface, and then baked without any chemical treatment for SEM study. This 'direct baking' technique is effective for comparing minute structures of the frustules, because completed combination of every part of the frustules can be observed. 相似文献
7.
Many studies have focused on the stabilization of additive manufacturing (AM) in microgravity for its use in various space projects. Nevertheless, this paper presents a vital clue for innovating metal AM technologies from the perspective of high gravity. High-gravitational powder bed fusion has an excellent potential to address various challenges in AM, such as density enhancement, spatter suppression, and precise fabrication. This study summarizes an analogy among phenomena in different gravitational fields and establishes a combined machine for centrifuge and powder bed fusion. The results confirm the spatter suppression and fine-powder availability in high gravity, both theoretically and experimentally. 相似文献
8.
Yusuke Furuta Hiroyuki Nishikawa Takahiro Satoh Yasuyuki Ishii Tomihiro Kamiya Ryota Nakao Satoshi Uchida 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(12-13):2285-2288
Fabrication of high-aspect-ratio microstructures was performed by proton beam writing (PBW) using a microbeam line at Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA Takasaki, JAPAN. As one of the applications of the high-aspect-ratio structures micro-machined by PBW, we utilized the high-aspect pillars for electric-micro filters of microbes such as Escherichia coli and Yeast based on the dielectrophoretic force. The filter is equipped with high-aspect pillars with a height of ~20 μm and a diameter of ~1 μm on a glass plate. Evaluation of the dielectrophoresis (DEP) device for capturing E. coli and Yeast was made using either observation by optical microscope or photoluminescence (PL) measurements. 相似文献
9.
Michael Singh Serhat Akkaya Mark Preuß Franziska Rademacher Mersedeh Tohidnezhad Yusuke Kubo Peter Behrendt Jan-Tobias Weitkamp Thilo Wedel Ralph Lucius Regine Glser Jürgen Harder Andreas Bayer 《International journal of molecular sciences》2022,23(5)
Platelet-released growth factors (PRGFs) or other thrombocyte concentrate products, e.g., Platelet-Rich Fibrin (PRF), have become efficient tools of regenerative medicine in many medical disciplines. In the context of wound healing, it has been demonstrated that treatment of chronic or complicated wounds with PRGF or PRF improves wound healing in the majority of treated patients. Nevertheless, the underlying cellular and molecular mechanism are still poorly understood. Therefore, we aimed to analyze if PRGF-treatment of human keratinocytes caused the induction of genes encoding paracrine factors associated with successful wound healing. The investigated genes were Semaphorin 7A (SEMA7A), Angiopoietin-like 4 (ANGPLT4), Fibroblast Growth Factor-2 (FGF-2), Interleukin-32 (IL-32), the CC-chemokine-ligand 20 (CCL20), the matrix-metalloproteinase-2 (MMP-2), the chemokine C-X-C motif chemokine ligand 10 (CXCL10) and the subunit B of the Platelet-Derived Growth Factor (PDGFB). We observed a significant gene induction of SEMA7A, ANGPLT4, FGF-2, IL-32, MMP-2 and PDGFB in human keratinocytes after PRGF treatment. The CCL20- and CXCL10 gene expressions were significantly inhibited by PRGF therapy. Signal transduction analyses revealed that the PRGF-mediated gene induction of SEMA7A, ANGPLT4, IL-32 and MMP-2 in human keratinocytes was transduced via the IL-6 receptor pathway. In contrast, EGF receptor signaling was not involved in the PRGF-mediated gene expression of analyzed genes in human keratinocytes. Additionally, treatment of ex vivo skin explants with PRGF confirmed a significant gene induction of SEMA7A, ANGPLT4, MMP-2 and PDGFB. Taken together, these results describe a new mechanism that could be responsible for the beneficial wound healing properties of PRGF or related thrombocytes concentrate products such as PRF. 相似文献
10.
Naw Rutha PAW Takuma KIMURA Tatsuo ISHIJIMA Yasunori TANAKA Yusuke NAKANO Yoshihiko UESUGI Shiori SUEYASU Shu WATANABE Keitaro NAKAMURA 《等离子体科学和技术》2021,23(10):105505-203
Titanium dioxide (TiO2) nanopowder (P-25;Degussa AG) was treated using dielectric barrier discharge (DBD) in a rotary electrode DBD (RE-DBD) reactor.Its electrical and optical characteristics were investigated during RE-DBD generation.The treated TiO2 nanopowder properties and structures were analyzed using x-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR).After RE-DBD treatment,XRD measurements indicated that the anatase peak theta positions shifted from 25.3° to 25.1°,which can be attributed to the substitution of new functional groups in the TiO2 lattice.The FTIR results show that hydroxyl groups (OH) at 3400 cm-1 increased considerably.The mechanism used to modify the TiO2 nanopowder surface by air DBD treatment was confirmed from optical emission spectrum measurements.Reactive species,such as OH radical,ozone and atomic oxygen can play key roles in hydroxyl formation on the TiO2 nanopowder surface. 相似文献