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排序方式: 共有1221条查询结果,搜索用时 15 毫秒
41.
Shuntaro Suzuki Tsuneo Suzuki Hisayuki Suematsu Weihua Jiang Kiyoshi Yatsui 《Thin solid films》2004,457(1):139-142
Titanium iron oxide (Ti-Fe-O) thin films have been successfully deposited by pulsed laser deposition (PLD). Experiments were carried out by using some targets. One was a Ti-50 at.% Fe-sintered target, while the others were Ti and Fe plates with various surface area ratio [SR=SFe/(SFe+STi)] from 30 to 70%. The thin films were analyzed by X-ray diffractometry, Rutherford backscattering spectroscopy (RBS) and transmission electron microscopy (TEM). From XRD analysis, the main phase in the thin films deposited at SR=30 and 50% was β-Ti (Fe). By increasing SR to 70%, the main phase of the thin film changed to TiFe. By phase diagram, composition of TiFe must be between Ti-47.5-50.3 at.% Fe at a temperature of 1085 °C. However, the composition of the thin film deposited at SR=70% was found to be Ti0.15Fe0.62O0.23. Thus, the composition of Fe in the thin film was much greater than the solubility limit. This fact suggests two possibilities. One is that the thin films, which we have deposited, were in a metastable state. The other is that metal oxides of amorphous state could be contained in the thin film. 相似文献
42.
Xi Chen Guo-Ping Wu Qiu-Feng Cai Guang-Ming Liu Kiyoshi Osatomi Wen-Jin Su Min-Jie Cao 《Food chemistry》2012,130(3):679-686
An aminopeptidase was purified from Japanese flounder skeletal muscle to homogeneity by ammonium sulphate fractionation and three chromatographies. The enzyme was approximately 100 kDa with isoelectric point of 5.7 as estimated by two-dimensional polyacrylamide gel electrophoresis. Its optimum temperature and pH were 45 °C and 7.5, respectively. According to peptide mass fingerprinting study, the enzyme revealed high identity to a puromycin-sensitive aminopeptidase. It had a broad specificity toward aminopeptidase substrates and preferred to hydrolyse Lys-MCA with kcat/Km of 8.1 × 106 M?1 s?1, and the activation energy (Ea) of 72.5 kJ M?1. Metal-chelating agents effectively inhibited the enzyme activity, and Zn2+, Mn2+ and Co2+ significantly restored the apoenzymatic activity dialysed by EDTA, whilst inhibitors to other proteinases did not show much effect. Furthermore, bestatin strongly inhibited its activity. These results indicate that the purified enzyme is a metalloaminopeptidase which would possibly contribute to free amino acids increase in fish muscle. 相似文献
43.
44.
Kento Ishii Chika Matsunaga Kiyoshi Kobayashi Adam J. Stevenson Caroline Tardivat Tetsuo Uchikoshi 《Journal of the European Ceramic Society》2021,41(4):2709-2715
The Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF)-based multi-layered oxygen separation membrane was fabricated by the sequential electrophoretic deposition (EPD) process. A thin porous/dense bi-layer of BSCF was formed on a thick porous support of BSCF. The porous support prepared by a sacrificial template method using BSCF powder mixed with wheat starch (30 wt%) as a pore-forming agent, followed by uniaxial pressing and low-temperature sintering, was directly used as an EPD electrode. A thin BSCF layer was first formed on the porous support, and then a thin BSCF + PMMA (polymethyl methacrylate) layer was sequentially formed on the thin BSCF layer using a bimodal suspension of BSCF and PMMA. A 30-μm thin porous/dense bi-layer of BSCF of which the total thickness was obtained by optimizing the processes of EPD and subsequent co-sintering. The oxygen separation performance of 3.7 ml (STP) min?1 cm?2 at 860 °C was achieved for the BSCF-based multi-layered oxygen separation membrane. 相似文献
45.
Takuya Isomura Akimasa Takeuchi Kenta Shimba Kiyoshi Kotani Yasuhiko Jimbo 《Electrical Engineering in Japan》2014,187(4):42-50
Recently, there has been abundant research using multineuron recording, but there are many problems with extracting the features from the obtained spike time series, which are huge in volume and complex. Here we introduce a new method of estimating synaptic connection strengths between neurons by fitting to the Izhikevich model by maximum likelihood estimation. We demonstrate that our method can estimate connection strengths from spike time series given by a simulated neural ensemble and can estimate nonconnectivity between two independent cultured neuronal networks. These results suggest that our method is applicable to network and plasticity analysis of neuronal networks. 相似文献
46.
Shinji Fukuda Kazuhiko Shimada Noriya Izu Hiroyuki Miyazaki Shoji Iwakiri Kiyoshi Hirao 《Journal of Materials Science: Materials in Electronics》2018,29(14):11688-11698
We observed crack generation and structural changes in electroless nickel–phosphorus (Ni–P) plating layers formed on copper-metalized silicon nitride substrates both during thermal cycling from ? 40 to 250 °C and during storage (not cycling) at 250 °C in order to investigate the effect of the phosphorus contents on crack generation and growth in the Ni–P platings. The used platings contained phosphorus at three different contents: 2.1 wt% [Ni–P(low)], 6.5 wt% [Ni–P(med)], and 10.9 wt% [Ni–P(high)]. The generation time and the amount of cracks were strongly dependent on their phosphorus contents. More cracks appeared after thermal cycling than after storage at 250 °C. In Ni–P(low), cracks were generated after 200 thermal cycles, whereas no cracks were observed even after 250 h of storage at 250 °C. In Ni–P(med) and Ni–P(high), both during thermal cycling and storage at 250 °C, cracks formed during or after crystallization of the amorphous layers. These results suggest that the primary factors affecting the generation of cracks in electroless Ni–P platings are crystallization of the Ni–P platings and repeated changes in thermal stress. 相似文献
47.
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
48.
Research and Development of the Coprecipitation Process for Lanthanum Germanate Oxyapatite
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Kiyoshi Kobayashi Shouta Kitajima Yukihito Igarashi Tohru Higuchi Yoshio Sakka 《Journal of the American Ceramic Society》2015,98(1):66-70
Although lanthanum germanate oxyapatite (La–Ge–O) has shown good potential for use as a solid electrolyte in energy storage applications, its synthesis has been challenging by either solid‐ or solution‐state methods. In this study, a new synthesis of La–Ge–O was developed through a coprecipitation technique, in which a highly concentrated homogeneous aqueous solution of La and Ge was prepared from aqueous ammonium germanate and lanthanum nitrate solutions with the addition of dilute nitric acid. Several precipitates were formed by pH manipulation, including an amorphous material obtained at pH > 3. Compared to the individual precipitation behaviors of the parent compounds, the amorphous precipitate was formed only from the aqueous two‐component mixture, and appeared to contain both metals. This material was transformed into crystalline mixtures upon heating at 1273 K. The crystalline phases were La2Ge3O9 and hexagonal‐type GeO2 when the precipitate was formed below pH 8, and the La–Ge–O and La2Ge2O7 phases when the precipitate was formed around pH 8. Product formation from the coprecipitate was discussed based on X‐ray diffraction and thermal analyses. The improved availability of La–Ge–O will allow more extensive investigations of its useful properties. 相似文献
49.
Hisatoyo Morinaga Yoshihide Kiyokawa Ryosuke Fujikawa Daisuke Nagai Hiroshi Morikawa 《Polymer Bulletin》2014,71(9):2421-2435
Partially biobased polyamphiphile-bearing reactive epoxy groups in the side chains were obtained in 62–78 % yields by a radical copolymerization of limonene oxide (LO) and PEG methylacrylate (PEGA) with different feed ratios. Degree of LO incorporation into the copolymer was determined as 12–23 % by 1H NMR spectroscopic analysis. The copolymer having LO unit:PEGA unit = 19:81 formed polymer associates in water, particle diameter of which was ranged mainly from 4 to 66 nm and hydrodynamic mean diameter was 12.3 nm. Its critical micelle concentration was determined as 0.53 g/L by fluorescence spectroscopic analysis. A cross-linking reaction of the epoxy groups in the side chains was conducted with 3.97 mol% (to the epoxy group) of branched poly(ethylene imine) as a cross-linker to give the corresponding hydrogel in 56 % yield. The hydrogel can absorb water as much as 13 times its own mass. 相似文献
50.
Kiyoshi Oguchi Kohei Sanui Naoya Ogata Yoichi Takahashi Tomihiro Nakada 《Polymer Engineering and Science》1989,29(6):353-358
Acetalized poly(vinyl alcohol)s which were synthesized from poly(vinyl alcohol) (PVA) and aldehyde or ketone were evaluated as electron beam (EB) resists, in order to investigate the relationship between EB sensitivity and chemical structures of the polymers. It was found that the acetalized PVAs were easily crosslinked by EB exposure. The main mechanism of crosslinking may be radical reaction at acetal group. The sensitivity of the acetalized PVA depended on the structure of the acetal group. Acetalized PVAs synthesized from benzaldehyde, in which the electron attracting group was substituted on the benzene ring and from linear aliphatic aldehyde having a long alkyl chain, had high sensitivity. A high sensitivity of 7.2 × 10−7 C/cm2 was attained when the acetalized PVA synthesized from p-chloro-benzaldehyde was used. Acetalized PVAs synthesized from PVA and aldehyde having a cyclic structure had an excellent dry etching durability and were suitable as negative EB resists. 相似文献