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排序方式: 共有776条查询结果,搜索用时 31 毫秒
31.
Junichi Takahashi Masahiko Shimada Kouta Iwasaki Hisanori Yaname 《Journal of Electroceramics》2006,17(1):95-98
Single crystals of Bi and Cu-doped Ca3Co2O6were synthesized in a molten K2CO3flux. Using an obtained single crystal of (Ca0.985(5)Bi0.015(5))3(Co0.990(3)Cu0.010(3))2O6elongated to the c-axis direction of the crystal structure, the electric resistivity (ρ) and Seebeck coefficient (S) were measured from room temperature to over 1000 K in air. The single crystal showed p-type semiconducting behavior with ρ values of 1.8 Ω cm at 303 K and 0.017 Ω cm at 1000 K. The S values were +254 μ VK− 1 at 325 K, +360 μ VK− 1 at 420 K, and +214 μ VK− 1 at 1000 K. The power factor (S
2
ρ
− 1) increased with an increase of temperature and attained 2.70 × 10− 4 Wm− 1K− 2 at 1000 K. 相似文献
32.
Yasushi Yagi Wataru Nishi Nels Benson Masahiko Yachida 《Machine Vision and Applications》2003,14(2):112-120
Described here is a method for estimating rolling and swaying motions of a mobile robot using optical flow. We have proposed
an image sensor with a hyperboloidal mirror for the vision-based navigation of a mobile robot. Its name is HyperOmni Vision.
The radial component of optical flow in HyperOmni Vision has a periodic characteristic. The circumferential component of optical
flow has a symmetric characteristic. The proposed method makes use of these characteristic to estimate robustly the rolling
and swaying motion of the mobile robot.
Correspondence to: Y. Yagi e-mail: y-yagi@sys.es.osaka-u.ac.jp 相似文献
33.
One-step route to a hybrid TiO2/TixW1?xN nanocomposite by in situ selective carbothermal nitridation
Zo? Schnepp Martin J Hollamby Masahiko Tanaka Yoshitaka Matsushita Yoshio Katsuya Yoshio Sakka 《Science and Technology of Advanced Materials》2012,13(3)
Metal oxide/nitride nanocomposites have many existing and potential applications, e.g. in energy conversion or ammonia synthesis. Here, a hybrid oxide/nitride nanocomposite (anatase/TixW1−xN) was synthesized by an ammonia-free sol–gel route. Synchrotron x-ray diffraction, complemented with electron microscopy and thermogravimetric analysis, was used to study the structure, composition and mechanism of formation of the nanocomposite. The nanocomposite contained nanoparticles (<5 nm diameter) of two highly intermixed phases. This was found to arise from controlled nucleation and growth of a single oxide intermediate from the gel precursor, followed by phase separation and in situ selective carbothermal nitridation. Depending on the preparation conditions, the composition varied from anatase/TixW1−xN at low W content to an isostructural mixture of Ti-rich and W-rich TixW1−xN at high W content. In situ selective carbothermal nitridation offers a facile route to the synthesis of nitride-oxide nanocomposites. This conceptually new approach is a significant advance from previous methods, which generally require ammonolysis of a pre-synthesized oxide. 相似文献
34.
Ryoka Uchiyama Eriko Toyoda Miki Maehara Shiho Wasai Haruka Omura Masahiko Watanabe Masato Sato 《International journal of molecular sciences》2021,22(5)
Osteoarthritis of the knee (OAK) is a chronic degenerative disease and progresses with an imbalance of cytokines and macrophages in the joint. Studies regarding the use of platelet-rich plasma (PRP) as a point-of-care treatment for OAK have reported on its effect on tissue repair and suppression of inflammation but few have reported on its effect on macrophages and macrophage polarization. Based on our clinical experience with two types of PRP kits Cellaid Serum Collection Set P type kit (leukocyte-poor-PRP) and an Autologous Protein Solution kit (APS leukocyte-rich-PRP), we investigated the concentrations of humoral factors in PRPs prepared from the two kits and the effect of humoral factors on macrophage phenotypes. We found that the concentrations of cell components and humoral factors differed between PRPs purified using the two kits; APS had a higher concentration of M1 and M2 macrophage related factors. The addition of PRP supernatants to the culture media of monocyte-derived macrophages and M1 polarized macrophages revealed that PRPs suppressed M1 macrophage polarization and promoted M2 macrophage polarization. This research is the first to report the effect of PRPs purified using commercial kits on macrophage polarization. 相似文献
35.
36.
Masahiko Okumura Ayaka Ikado Yasuhiro Saito Hideyuki Aoki Takatoshi Miura Yoshiaki Kawakami 《International Journal of Hydrogen Energy》2012
In-situ and transient visualizations of the packing structure of a hydrogen storage alloy bed are carried out using an X-ray computed tomography (CT) system. The packing structure is clearly observed on the microscale using the CT system. When the alloy bed is subjected to hydrogen absorption–desorption cycles, the pulverization progresses from the lower to the upper regions of the bed. After several hydrogen absorption–desorption cycles, the packing structure in the lower region of the bed changes and the microstructural void decreases slightly. Based on these results, we propose a pulverization mechanism of the packed bed in which the friction between particles affects the pulverization process. 相似文献
37.
Kazushige Ishida Yoichi Wada Masahiko Tachibana Nobuyuki Ota Motohiro Aizawa 《Journal of Nuclear Science and Technology》2013,50(11):1071-1082
The effects of water chemistry distribution on the potential of a reference electrode and of the potential distribution on the measured potential should be known qualitatively to obtain accurate electrochemical corrosion potential (ECP) data in BWRs. First, the effects of oxygen on a platinum reference electrode were studied in 553 K pure water containing dissolved hydrogen (DH) concentration of 26–105 μg kg?1 (ppb). The platinum electrode worked in the same way as the theoretical hydrogen electrode under the condition that the molar ratio of DH to dissolved oxygen (DO) was more than 10 and that DO was less than 100 ppb. Second, the effects of potential distribution on the measured potential were studied by using the ECP measurement part without platinum deposition on the surfaces connected to another ECP measurement part with platinum deposition on the surfaces in 553 K pure water containing 100–130 ppb of DH or 100–130 ppb of DH plus 400 ppb of hydrogen peroxide. Measured potentials for each ECP measurement part were in good agreement with literature data for each surface condition. The lead wire connecting point did not affect the measured potential. Potential should be measured at the nearest point from the reference electrode in which case it will be not affected by either the potential distribution or the connection point of the lead wire in pure water. 相似文献
38.
Masahiko Hayashi Kazuya Yoshimoto Naohito Hirata Kiyoshi Tanaka Nobuki Oguni Katsumasa Harada Akio Matsushita Yasuhiro Kawachi Hiroshi Sasaki 《Israel journal of chemistry》2001,41(4):241-246
Highly enantioselective addition of diketene to aldehydes was achieved by using novel Schiff base—titanium alkoxide complexes. Up to 92% ee of 5-hydroxy-3-oxoesters was obtained. This procedure provides an efficient method for the asymmetric synthesis of potential inhibitors of HMG coenzyme reductase. 相似文献
39.
Hirobumi Shibata Tomoaki Morita Taku Ogura Keishi Nishio Hideki Sakai Masahiko Abe Mutsuyoshi Matsumoto 《Journal of Materials Science》2009,44(10):2541-2547
Mesostructured zirconia particles having monoclinic-type crystalline walls were prepared using a low-temperature crystallization
technique. Crystalline zirconia particles with highly-ordered mesostructures were obtained through the sol–gel process of
zirconium sulfate tetrahydrate at 333 K in the presence of molecular self-assemblies of cetyltrimethylammonium bromide (CTAB)
or mixtures of CTAB and anionic molecules such as sodium dodecyl sulfate and sodium p-toluenesulfonate. Variations in the molar ratios of CTAB and the chemical species of anionic molecules led to the variations
in the periods of highly-ordered zirconia having crystalline walls. Calcination of the mesostructured zirconia particles prepared
using templates consisting solely of CTAB yielded crystalline mesoporous zirconia particles. 相似文献
40.
Shin-ichiro Ohno Gregor P. C. Drummen Masahiko Kuroda 《International journal of molecular sciences》2016,17(2)
Many types of cells release phospholipid membrane vesicles thought to play key roles in cell-cell communication, antigen presentation, and the spread of infectious agents. Extracellular vesicles (EVs) carry various proteins, messenger RNAs (mRNAs), and microRNAs (miRNAs), like a “message in a bottle” to cells in remote locations. The encapsulated molecules are protected from multiple types of degradative enzymes in body fluids, making EVs ideal for delivering drugs. This review presents an overview of the potential roles of EVs as natural drugs and novel drug-delivery systems. 相似文献