http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lubricating property of cyano-based ionic liquids against hard materials
Shouhei Kawada,Keisuke Sato,Seiya Watanabe,Shinya Sasaki 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.12
Ionic liquids are expected to be used as a new lubricants and lubricant additives because of their unique properties. However, cyanobased ionic liquids have exhibited poor lubricating property with steel/steel contacts. We evaluated the lubricating properties of cyanobased ionic liquids with steel/hard materials contacts. TiO 2 , Al 2 O 3 , and tetrahedral amorphous carbon (ta-C) DLC were used as hard materials. Six types of ionic liquids, as combination of two types of cations ([EMIM], [BMPL]) and three types of cyanide anions ([DCN], [TCC] and [TCB]), were selected. In sliding tests of steel/TiO 2 and steel/Al 2 O 3 lubricated with [EMIM][DCN], [BMPL][DCN], [EMIM][TCC], [BMPL][TCC] exhibited low friction coefficients of less than 0.1. In addition, steel/Al 2 O 3 and steel/ta-C DLC lubricated with [BMPL][TCB] exhibited very low friction coefficients less than 0.05. On the other hand, high friction coefficients were observed at steel/TiO 2 and steel/Al 2 O 3 contacts lubricated with [EMIM][TCB] and steel/ta-C DLC contact lubricated with [EMIM] cation group. Peeling of the ta-C DLC was observed when [EMIM] cation group was used. ToF-SIMS analysis indicated that the anion was adsorbed on the worn surfaces in the case of low frictional conditions. However, both ions were hardly observed in the case of high frictional conditions. It is considered that the ionic liquids underwent tribo-decomposition on the worn surfaces at low friction coefficient. To evaluate the degree of tribo-decomposition, Thermogravimetric analysis (TGA) was used. TGA results indicated that [EMIM][TCB], which exhibited high friction coefficient, had the most highest stability among all ionic liquids. Low stability ionic liquids, however, showed a tendency for low friction coefficient. These results suggest that lubricating properties are related to the stability of ionic liquids.
A Geometric Compensation Method for Image Watermarking Schemes and Its Required Accuracy
Shouhei KAMIMURA,Masaaki FUJIYOSHI,Hitoshi KIYA 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7
This paper proposes a geometric compensation method for improving the watermark extraction ability. The proposed method is independent of watermarking schemes, whereas the conventional approach makes the particular watermarking scheme resistant to geometric deformation. The proposed method estimates geometric parameters by phase-only correlation technique using the original image rather than the stego image in which watermark is hidden. The required accuracy for geometric estimation is investigated by computer simulation, and performances are evaluated using real printed-and-scanned images.
Measurement of Gamma-ray Yield from Thick Carbon Target Irradiated by 5 and 9 MeV Deuterons
Araki, Shouhei,Kondo, Kazuhiro,Kin, Tadahiro,Watanabe, Yukinobu,Shigyo, Nobuhiro,Sagara, Kenshi The Korean Association for Radiation Protection 2017 방사선방어학회지 Vol.42 No.1
Background: The design of deuteron accelerator neutron source facilities requires reliable yield estimation of gamma-rays as well as neutrons from deuteron-induced reactions. We have so foar measured systematically double-differential thick target neutron yields (DDTTNYs) for carbon, aluminum, titanium, copper, niobium, and SUS304 targets. In the neutron data analysis, the events of gamma-rays taken simultaneously were treated as backgrounds. In the present work, we have re-analyzed the experimental data for a thick carbon target with particular attention to gamma-ray events. Materials and Methods: Double-differential thick target gamma-ray yields from carbon irradiated by 5 and 9 MeV deuterons were measured using an NE213 liquid organic scintillator at the Kyushu University Tandem accelerator Laboratory. The gamma-ray energy spectra were obtained by an unfolding method using FORIST code. The response functions of the NE213 detector were calculated by EGS5 incorporated in PHITS code. Results and Discussion: The measured gamma-ray spectra show some pronounced peaks corresponding to gamma-ray transitions between discrete levels in residual nuclei, and the measured angular distributions are almost isotropic for both the incident energies. Conclusion: PHITS calculations using INCL, GEM, and EBITEM models reproduce the spectral shapes and the angular distributions generally well, although they underestimate the absolute gamma-ray yields by about 20%.
Phase Separation of Antiferromagnetism and Superconductivity in RbxFe2−ySe2 Observed by Using Rb NMR
Yoshiaki Kobayashi,Shunsuke Saiki,Shouhei Kototani,Masayuki Itoh,Masatoshi Sato 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3
We have carried out 87Rb NMR measurements on single crystals with and without the superconducting(SC) transition to clarify whether the SC and the antiferromagnetic (AFM) states aremicroscopically coexistent or just phase-separated in the Rb-intercalated iron-selenide RbxFe2−ySe2. The 87Rb NMR spectra observed at temperature below 300 K for these crystals are clearly separableinto two parts with different structures and widths. The broader spectrum can be explainedby the presence of a region with an AFM spin structure proposed by neutron scattering studies. The narrower spectrum in the crystal with the SC transition can be understood from the temperaturedependences of the spectral frequency-position and shape to stem from the SC region withTc = 30.8 K. Thus, we can clearly conclude that the superconductivity and the antiferromagnetismin the present system are phase-separated. Also, the crystal without the SC transition has twophase-separated regions with respective magnetic transitions at 500 and 50 K.
Ueda, Tetsuhiko,Takase, Shouhei,Ikeda, Tadashige,Iwahori, Yutaka The Korean Society for Composite Materials 2008 Advanced composite materials Vol.17 No.2
As the first step in discussing the reliability of composite structures, a fundamental study was performed to obtain the scattering characteristics of glass-fiber reinforced plastics (GFRP) and woven carbon fiber reinforced plastics (WCFRP) as well as a reference metal. The Euler buckling load was obtained experimentally for each material. The experiments were conducted for specified rectangular specimens with simply supported edges. A new attachment to realize the simply support boundary conditions for composite materials have been prepared before these experiments. The scattering data in the results for GFRP and WCFRP composites were compared with those of a typical metal of aluminum alloy. The experimental data were also compared with numerical simulations including the uncertainties.
Magnetism and Superconductivity in RbxFe2−ySe2
Kazuki Ohishi,Masatoshi Sato,Shouhei Kototani,Shunsuke Saiki,Yoshiaki Kobayashi,Masayuki Itoh 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12
We have performed zero-field muon spin relaxation measurements in single-crystalline samplesof superconducting (SC) RbxFe2−ySe2 (Tc = 29 K) and non-SC RbxFe2−ySe2 in order to elucidatewhether there is difference in the magnetic states between SC and non-SC systems. In the SCsample, no temperature dependence of the muon spin polarization was observed at temperaturesbelow 40 K while a decrease in the spin polarization was observed in the non-SC sample withdecreasing temperature. This suggests that a new magnetically ordered state seems to develop inthe non-SC sample.