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51.
Jun-Woo ParkKazuki Yoshida Naoki TachikawaKaoru Dokko Masayoshi Watanabe 《Journal of power sources》2011,196(4):2264-2268
The physicochemical and electrochemical properties of the binary ionic liquid (IL), lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) dissolved in N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)amide (DEMETFSA), were investigated. The ionic conductivity of the binary IL decreased with an increase in LiTFSA concentration. The self-diffusion coefficients of Li+, DEME+, and TFSA− dissolved in the IL were measured by using the pulsed-field-gradient spin-echo (PGSE) NMR method. The self-diffusion coefficient of each ionic species was also found to decrease with increasing concentration of LiTFSA. The limiting current density in the IL electrolyte was evaluated by chronoamperometry using symmetric Li|IL|Li cell. The results suggest that the diffusion process of Li(I) in the IL dominates the limiting current density in the cell. The highest limiting current density is achieved at a concentration of 0.64 mol dm−3 of LiTFSA. 相似文献
52.
Shiro Seki Takeshi Kobayashi Nobuyuki Serizawa Yo Kobayashi Katsuhito Takei Hajime Miyashiro Kikuko Hayamizu Seiji Tsuzuki Takushi Mitsugi Yasuhiro Umebayashi Masayoshi Watanabe 《Journal of power sources》2010,195(18):6207-6211
The physicochemical and electrochemical properties of three 1-alkyl-2,3,5-trimethylpyrazolium cation-based room-temperature ionic liquids with various alkyl chain lengths were investigated. The temperature dependences of density, viscosity, and ionic conductivity were obtained by precise measurements. Electrolyte properties of these room-temperature ionic liquids were also examined from the viewpoint of their uses in lithium secondary batteries ([LiCoO2 positive electrode|electrolyte|lithium metal negative electrode]). It was found that the alkyl chain length affects the charge–discharge performances of cells. 相似文献
53.
This paper proposes a design method for short track-seeking control based on one degree of freedom (ODOF) control and initial value compensation (IVC). IVC uses nonzero initial values of the feedback controller to improve the step reference response of the ODOF tracking control system. This makes feedforward control unnecessary to shape the transient response of short track seeking. As a result, the amount of computation during short track seeking may be minimal. The proposed design method minimizes tracking errors in multirate control framework for a step reference input taking into account the inter-sampling behavior. The effectiveness of the proposed method is shown by simulation and experiment. 相似文献
54.
By using a high-spatial-resolution scanning infrared polariscope, in-plane components of residual strain have been characterized
quantitatively in 2′Φ wafers of Fe-doped InP( 100) single crystals grown by the liquid-encapsulated Czochralski (LEC) and
the vapor pressure controlled Czochralski (VCZ) methods. The twodimensional distribution maps of LEC-grown wafers reveal characteristic
fine structures such as slip-like patterns originated from crystallographic glides during the crystal growth process, highly
strained spots and filaments due to inclusions or voids inside the wafer, or due to scratches on the surface. The sliplike
patterns are seldom observed in the VCZ-grown wafers. The residual strain value averaged over the whole region of wafer is
also examined, together with etch pit density and resistivity, as a function of the solidified fraction. It is found that
the residual strain in the Fe-doped InP crystals grown by the LEC and VCZ methods mainly depends on the thermal stress during
the growth process rather than on the impurity-hardening effect of Fe.Key words: InP, infrared polariscope, liquid-encapsulated Czochralski (LEC) method, residual strain, vapor pressure controlled Czochralski
(VCZ) method 相似文献
55.
Minoru Takahashi Koichiro Adachi Ruben L. Menchavez Masayoshi Fuji 《Journal of Materials Science》2006,41(7):1965-1972
In this study, we propose a new process to fabricate electrically semi-conductive alumina by the combination of gelcasting
and reduction sintering. The process is similar to the conventional gelcasting method except for varying amounts of methacrylamide
monomer dosages at 2.83, 5.50, and 8.04 wt% relative to the mass of the slurry. Correspondingly, the rheological evaluation
of aqueous slurry was conducted. The resulting fluidity exhibited that monomer dosage until 8.04 wt% yielded slurry viscosity
of 1628 MPA·s at shear rate of 20 s−1, which was feasible for gelcasting without noticeable casting defects. The freshly gelled bodies were demolded, carefully
dried, and then sintered at different schedules in nitrogen atmosphere. The reduction-sintered samples were re-sintered in
air for comparative evaluation of physical property. The sintered alumina body was characterized by electrical resistance,
X-ray diffraction, and scanning electron microscopy. The results showed that monomer additions and sintering schedule significantly
affect in lowering electrical resistivity. The obtained lowest value was 3.6 × 106 Ω-cm with 8.04 wt% monomer dosage and sintering at 1550°C with 2 h holding time. The resulting material is classified as
semi-conductive, which is potential for electrostatic shielding applications. The effect of physical property and microstructure
on electrical conductivity and the corresponding reaction mechanism were discussed in details. 相似文献
56.
Babita Gupta A. Kapoor R. M. Mehra Tetsuo Soga Takashi Jimbo Masayoshi Umeno 《Solar Energy Materials & Solar Cells》2003,79(3):305-311
Amorphous carbon (a-C) is a potential material for the development of low-cost and high-efficiency solar cell. We report the study of the influence of light soaking up to 100 h on n-C/p-Si heterojunction solar cell. It is observed that the deterioration in the fill factor and the efficiency are significantly smaller as compared to that observed in a-Si:H solar cell. Variations in the temperature coefficients of the I–V characteristics subjected to light degradation and recovery has also been investigated. A good correlation between change in the temperature coefficient and the degradation/recovery state of cell's conversion efficiency has been observed. 相似文献
57.
MMIC technology is recently progressing at a rapid rate and is now being applied in communications systems. However, there remain few practical applications. This is mainly due to the high cost of conventional mmics because of the small market size and specialized needs. This paper introduces three new technical approaches that overcome the problems: uniplanar mmic, line unified fet^lufet), and multilayer mmic. Concepts and several examples of these technologies are described. It is shown that these technologies are effective not only for cost reduction but also for increased performance. In addition, one example of system application is described. 相似文献
58.
Boron-doped hydrogenated amorphous carbon films grown by surface-wave mode microwave plasma chemical vapor deposition 总被引:1,自引:0,他引:1
Sudip Adhikari Dilip C. Ghimire Hare Ram Aryal Sunil Adhikary Hideo Uchida Masayoshi Umeno 《Diamond and Related Materials》2006,15(11-12):1909
We report the effects of boron (B) doping on optical and structural properties of the hydrogenated amorphous carbon thin films grown by surface-wave mode microwave plasma (SW-MWP) chemical vapor deposition (CVD) on n-type silicon and quartz substrates at room temperature. Argon and acetylene were used as a carrier and carbon source gases respectively. Analytical methods such as X-ray photoelectron spectroscopy (XPS), Nanopics 2100/NPX200 surface profiler, JASCO V-570 UV/VIS/NIR spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy were employed to investigate the properties of the films. Low atomic concentration of B (0.08 at.%) was found in the doped film. The optical band gap of the undoped film was 2.6 eV and it decreased to 1.9 eV for the B-doped film. Structural property shows the crystalline structure of the film and it has changed after incorporating B as a dopant. The structural modifications of the films leading to being more graphite in nature were confirmed by the Raman and FT-IR characterization. 相似文献
59.
Shumpei Ozawa Takuro Koda Masayoshi Adachi Suguru Shiratori Noriaki Takenaga Taketoshi Hibiya Masahito Watanabe 《亚洲传热研究》2008,37(7):421-430
We proposed a new approach to identify the frequencies of droplet rotation and m=±2 oscillation that degrade the accuracy of surface tension measurement by an oscillating droplet method. Frequencies of droplet rotation and m=±2 oscillation can be identified by a phase unwrapping analysis of time dependence of the deflection angle for the maximum diameter of the droplet image observed from above. The present method was validated, using test data with given frequencies. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(7): 421–430, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20214 相似文献
60.
Yu‐Ching Lin Yao‐Chuan Tsai Takahito Ono Pan Liu Masayoshi Esashi Thomas Gessner Mingwei Chen 《Advanced functional materials》2015,25(35):5677-5682
Microelectromechanical system (MEMS) actuators essentially have movable silicon structures where the mechanical motion can be activated electronically. The microscanner is one of the most successfully commercialized MEMS devices which are widely used for collecting optical information, manipulating light, and displaying images. While silicon is abundant, it is also brittle and stiff and when microprocessed, defects are not uncommon. These defects result in weakness under torsional stress and this has been the key factor limiting the scanning performance of the microscanner. Here a metallic glass (MG)‐based microscanner is reported with MG as the material for the moving torsion bars. The low elastic modulus, high fracture toughness, and high strength of MG offers, for the first time, an ultralarge rotating angle of 146° with power consumption lowered to the microwatt range, and a smaller driving force and better actuation performance, than conventional single crystal silicon and polycrystalline silicon. The high spatial resolution and large scanning field of the MG‐based microscanner are demonstrated in the tomographic imaging of a human finger. This development of an MG‐based MEMS possibly opens a new field of low‐powered MEMS devices with extreme actuation and enhanced sensing. 相似文献