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21.
Kubota Y. Nishi Y. Shintani K. Urabe T. Shimada K. Katsumoto T. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1994,82(4):537-543
Camcorders have been developed to be compact with high performance. Latest advancement of key technologies and devices such as digital signal processing LSI, six-layer printed circuit board with micro chips, high-speed power lens with linear motor, 103 K pixels 0.7-in LCD electronic viewfinder, and high-energy Li-ion battery are described. High-band format is also explained 相似文献
22.
We developed a wide-striped laser diode integrated with a microlens that provides good focusing characteristics through a small focusing spot. We calculated and demonstrated that a 60-μm-wide core and a 1.9-μm-high ridge is the best structure for fundamental index-guiding mode oscillation of a wide-striped laser diode. We integrated a wide-striped laser diode with the developed microlens in the Fresnel diffraction held, and demonstrated that a device with a 60-μm-wide core has a minimum focusing spot width of 2.0 μm in the horizontal direction. Also, we estimated the wavefront in the Fresnel diffraction field from the working distance error of a lens designed for a collimated incident beam, and showed that the working distance error, focusing spot width, and sidelobe can be improved by this estimated wavefront 相似文献
23.
Rui Morimoto Chisato Yokomori Akiko Kikkawa Akira Izumi Hideki Matsumura 《Thin solid films》2003,430(1-2):230-235
In this paper, bulk-Si metal–oxide–semiconductor field effect transistors (MOSFETs) are fabricated using the catalytic chemical vapor deposition (Cat-CVD) method as an alternative technology to the conventional high-temperature thermal chemical vapor deposition. Particularly, formation of low-resistivity phosphorus (P)-doped poly-Si films is attempted by using Cat-CVD-deposited amorphous silicon (a-Si) films and successive rapid thermal annealing (RTA) of them. Even after RTA processes, neither peeling nor bubbling are observed, since hydrogen contents in Cat-CVD a-Si films can be as low as 1.1%. Both the crystallization and low resistivity of 0.004 Ω·cm are realized by RTA at 1000 °C for only 5 s. It is also revealed that Cat-CVD SiNx films prepared at 250 °C show excellent oxidation resistance, when the thickness of films is larger than approximately 10 nm for wet O2 oxidation at 1100 °C. It is found that the thickness required to stop oxygen penetration is equivalent to that for thermal CVD SiNx prepared at 750 °C. Finally, complementary MOSFETs (CMOSs) of single-crystalline Si were fabricated by using Cat-CVD poly-Si for gate electrodes and SiNx films for masks of local oxidation of silicon (LOCOS). At 3.3 V operation, less than 1.0 pA μm−1 of OFF leakage current and ON/OFF ratio of 107–108 are realized, i.e. the devices can operate similarly to conventional thermal CVD process. 相似文献
24.
Characterization of C-S-H from Highly Reactive β-Dicalcium Silicate Prepared from Hillebrandite 总被引:1,自引:1,他引:0
Yoshihiko Okada Hideki Ishida Kaori Sasaki J. Francis Young Takeshi Mitsuda 《Journal of the American Ceramic Society》1994,77(5):1313-1318
β-dicalcium silicate synthesized by thermal dissociation of hydrothermally prepared hillebrandite (Ca2 (SiO3 )(OH)2 ) exhibits extremely high hydration activity. Characterization of the hydrates obtained and investigation of the hydration mechanism was carried out with the aid of trimethylsilylation analysis, 29 Si magic angle spinning nuclear magnetic resonance, transmission electron microscopy selected area electron diffraction, and XRD. The silicate anion structure of C-S-H consisted mainly of a dimer and a single-chain polymer. Polymerization advances with increasing curing temperature and curing time. The C-S-H has an oriented fibrous structure and exhibits a 0.73-nm dreierketten in the longitudinal direction. On heating, the C-S-H dissociates to form β-C2 S. The temperature at which βC2 S begins to form decreases with increasing chain length of the C-S-H or as the Ca/Si ratio becomes higher. The high activity of β-C2 S is due to its large specific surface area and the fact that the hydration is chemical-reaction-rate-controlled until its completion. As a result, the hydration progresses in situ and C-S-H with a high Ca/Si ratio is formed. 相似文献
25.
Yamaoka M. Maeda N. Shinozaki Y. Shimazaki Y. Nii K. Shimada S. Yanagisawa K. Kawahara T. 《Solid-State Circuits, IEEE Journal of》2006,41(3):705-711
The power consumption of a low-power system-on-a-chip (SoC) has a large impact on the battery life of mobile appliances. General SoCs have large on-chip SRAMs, which consume a large proportion of the whole LSI power. To achieve a low-power SoC, we have developed embedded SRAM modules, which use some low-power SRAM techniques. One technique involves expanding the write margin; another is a power-line-floating write technique, which enables low-voltage write operation. The power-line-floating write technique makes it possible to lower the minimum operating supply voltage by 100 mV. The other techniques involve using a process-variation-adaptive write replica circuit and reducing leakage current. These techniques reduce active power during write operations by 18% and reduce active leakage of the word-line driver by 64%. The prototype SRAM modules achieve 0.8-V operation, and a 512-kb SRAM module achieves 48.4-/spl mu/A active leakage and 7.8-/spl mu/A standby leakage with worst-leakage devices. 相似文献
26.
27.
The wide scattering in tool life of natural mono-crystalline diamond tools is considered to depend on intrinsic crystalline defects due to nitrogen impurities in raw diamond. In this paper, the correlation was investigated between the amounts and types of the impurity evaluated by infrared absorption (IRA) and the crater wear and chipping resistances. As a result, diamonds including less total amount of impurity show larger wear resistance and that with larger amount of B2-aggregates show larger chipping resistance. This suggests that the inspection by IRA can be a useful method for screening of raw diamond for highly durable cutting tools. 相似文献
28.
Shinichi Nomura Takushi Hagita Hiroaki Tsutsui Yoshihisa Sato Ryuichi Shimada 《Electrical Engineering in Japan》2008,164(2):37-43
The objective of this work is to discuss the concept of back‐to‐back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back‐to‐back DC link. In this case, each converter of the back‐to‐back system is used as a power conditioning system for the SMES coils. Since the AC–DC converter can be designed independently of the frequency of the power system, a two‐way switch is connected to the AC side of each converter. This two‐way switch can select the interconnected power systems. By using the two‐way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC–DC converters. For instance, lower‐cost power of each power network can be stored through two converters during the off‐peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back‐to‐back interconnection with SMES and discuses the optimal SMES configuration for a 300‐MW‐class back‐to‐back interconnection. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 37–43, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20482 相似文献
29.
Y. Yoshimura T. Sato H. Shimada N. Matsubayashi M Imamura A. Nishijima M. Higo S. Yoshitomi 《Catalysis Today》1996,29(1-4):221-228
Nickel-tungstate/γ-alumina (NiW) catalysts were prepared by an incipient wetness impregnation method using citric acid as a complexing agent. Citric acid has been used by our research group in preparing cobalt-molybdate and nickel -molybdate catalysts. The extended X-ray absorption fine structure (EXAFS) data of the impregnating solutions indicated that citric acid contributes to the formation of polytungstate anions that are smaller than the dodecatungstate ions formed when conventional ammoniacal solutions are used. Sulfided NiW catalysts prepared by using citric acid showed higher hydrogenation activity and hydrogenation selectivity than NiW catalysts prepared using the conventional ammoniacal solutions. 相似文献
30.
We report the clinical and pathologic findings of two patients with sporadic visceral myopathy. Both presented with chronic intestinal pseudo-obstruction that necessitated colectomy. Microscopically, typical changes of primary visceral myopathy were present, including variable fibrous replacement of the muscularis externa and vacuolar degeneration of myocytes. In addition, the muscle cells contained cytoplasmic inclusions that have only been recently reported in visceral myopathy. These inclusions were numerous and easily visible in routine hematoxylin-eosin-stained sections but greatly enhanced by periodic acid-Schiff staining. They were reactive immunohistochemically at their periphery and were seen to be myofibrils at various stages of degeneration on electron microscopy. Inclusions were present in both muscularis externae and muscularis mucosae and were identified in mucosal biopsy specimens, providing a means of diagnosing this type of myopathic change on endoscopic biopsies. 相似文献