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991.
Tetsuro Hori Takeshi Shibata Varutt Kittichungchit Hiroki Moritou Jun Sakai Hitoshi Kubo Akihiko Fujii Masanori Ozaki 《Thin solid films》2009,518(2):522-525
Photovoltaic cells, with a conducting polymer/fullerene (C60) interpenetrating heterojunction structure fabricated by spin-coating a conducting polymer onto a C60 thin film, have been investigated and demonstrated a high efficiency as solar cells based on organic materials. The photovoltaic properties of the solar cells with a structure of indium-tin-oxide (ITO)/C60/poly(3-hexylthiophene) (PAT6)/Au have been improved by the insertion of a molybdenum trioxide (VI) (MoO3) layer as a cathode buffer layer. In the solar cells with the structure of ITO/C60/PAT6/MoO3/Au, the energy conversion efficiency has been improved to 1.15% under AM1.5 (100 mW/cm2) illumination. 相似文献
992.
The precision and efficient machining of CVD-SiC ceramic to required quality has not been well established yet. In this paper, a comparative study was conducted to investigate the special aspects in grinding of CVD-SiC ceramic, with ELID method or rotary dressing method. The stability of surface roughness, effects of material properties and dressing methods on grinding results, effects of material properties and dressing methods on surface stress state, and microscopic analysis of ground CVD ceramics by both methods were well analyzed. In addition, a wheel-workpiece interaction model was proposed for the two dressing methods. 相似文献
993.
Hiromitsu Taniguchi Hitoshi Sugimoto Shigeru Yokoyama 《Electrical Engineering in Japan》2000,130(4):66-75
In order to study lightning problems of low‐voltage power distribution lines, lightning overvoltage waveforms were observed inside the homes of customers. The cause of lightning overvoltages was examined from observation of striking points by still cameras. Lightning overvoltages of 62 waveforms were recorded by observation over a period of about 3 1/2 years. Observed waveforms can be classified into three types of single polarity (positive or negative), both polarities (which change from positive to negative or negative to positive), and pulsive waveform. The causes of these lightning overvoltages which were estimated from striking points are shown as follows: (1) Induced lightning overvoltages on low‐voltage distribution lines. (2) Electric potential rise due to discharge of surge arresters or current of overhead ground wire. (3) Shift of lightning overvoltages from high‐voltage side of transformer to low‐voltage side, which is due to electromagnetic induction. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 66–75, 2000 相似文献
994.
Partial discharge (PD) may take place due to residual defects like metallic particles in SF6 gas‐insulated power apparatus such as GIS. However, the signal of PD occurring in SF6 gas is very weak and susceptible to external noise in air. Moreover, because of the complicated mechanism of PD, the radiation property of electromagnetic waves from PD has not as yet been clarified. Therefore, it is hard to distinguish the PD signal in SF6 gas from external noise. From the above points of view, we have been investigating the radiation mechanism of electromagnetic waves from PD. We measured the polarization characteristics of electromagnetic waves radiated from PD in comparison with those of half‐wave dipole antennas. The polarization characteristics of PD were explained by the theory of half‐wave dipole antenna, rather than that of an infinitesimal dipole antenna. Moreover, we compared the power spectrum for PD measured using a biconical antenna with that received from the half‐wave dipole antenna or infinitesimal dipole. It was found that the power spectrum for PD also corresponded to that for the half‐wave dipole antenna with a length of 50 cm. © 1999 Scripta Technica, Electr Eng Jpn, 126(4): 40–47, 1999 相似文献
995.
Yoshio Tanabe Chihiro Ohmori Hitoshi Nakayama Tomonori Uesugi Yoshiharu Mori Masahito Yoshii 《Electrical Engineering in Japan》1999,127(4):1-8
A ferrite‐loaded radio‐frequency (RF) cavity with resonant frequency of several megahertz is commonly used for proton synchrotrons. The resonant frequency of the cavity is shifted upward during beam acceleration by increasing the bias current. Because the bias current is swept sinusoidally at a high repetition rate, the RF characteristics of ferrites deteriorate due to disappearance of the magnetic anisotropy induced by Co2+ and Co3+ ions. This paper presents test results of the RF characteristics for three ferrites with large diameters of over 500 mm. The tests were carried out on our ferrite test bench. The RF frequency and the ac bias current vary from 2 MHz to 3.3 MHz and from 0 A to 1000 A, respectively, at the maximum frequency of 75 Hz. As the frequency of the ac bias current became high, deterioration of the RF characteristics and an increase in the ac bias current were observed. Consequently, it was verified that an ac bias test with full RF power using the test bench was inevitable for designing an actual RF cavity. © 1999 Scripta Technica, Electr Eng Jpn 127(4): 1–8, 1999 相似文献
996.
This paper deals with an identification method based on an automatic choosing function (ACF) for nonlinear systems. A full data region or an entire domain is partitioned into subdomains and the unknown nonlinear function to be estimated is approximately described by a linear equation on each subdomain. These linear equations are smoothly united into a single expression by the ACF, and the resulting model is linear in its parameters. Hence these parameters are easily evaluated by the linear least-squares method. The subdomains and the ACF are properly determined by a genetic algorithm that has a high potential for global optimization. Numerical experiments demonstrate the effectiveness of the proposed method. © 1998 Scripta Technica, Electr Eng Jpn, 125(4): 43–51, 1998 相似文献
997.
With a view to saving fuel, the use of regenerative burners as a heating source has been spreading in the field of industrial furnaces. By combining a burner with a regenerative air preheater, a second generation regenerative burner—the Rotary Regenerative Combustion System (RRX)—has been developed, which makes for lower emission of air pollutants and compactness, in addition to fuel savings. In this paper, heat transfer characteristics of RRX were deduced theoretically based on the heat transfer theory of a regenerative air preheater and investigated experimentally using two test rigs. A commercially operating fired heater was revamped in the summer of 1994 to install three sets of RRXs, and it has been successfully operated for one year. As a result, it was determined that the heat transfer rate in RRX can be predicted to within ±10%, by considering not only convective but also radiative heat transfer. Furthermore, it was confirmed both theoretically and experimentally that fuel efficiency exceeding 90% was stably attained in a commercial fired heater. Around 60 ppm of NOx emission (as dry, 6% O2) was also measured, although the preheated air temperature was calculated to be as high as 930 K. © 1999 Scripta Technica, Heat Trans Jpn Res, 27(8): 584–596, 1998 相似文献
998.
Method for introducing grafted chains consisting of two types of monomer components, acrylic acid (AA) and N-isopropylacrylamide (NIPAAm), into low-density polyethylene (PE) film (thickness = 25 μm) was investigated by two photografting technique using xanthone photoinitiator at 60°C. In the first method (one-step method), AA and NIPAAm binary monomers were graftcopolymerized onto PE film. In the second method (two-step method), AA was first photografted onto PE film and then NIPAAm was further introduced into the AA-grafted PE film by a second-step photografting. Water absorbencies of the grafted films (one- and two-step samples) prepared by the one- and two-step methods, respectively, decreased in the order of AA-grafted film > one-step sample > two-step sample > NIPAAm-grafted film. The water absorbency steeply decreased at 20 to 40°C with increasing temperature when immersed in water at the temperatures (5–60°C) for 24 h. Thermosensitivity, which was defined as the ratio of water absorbencies of the grafted samples at 5 and 60°C, was higher for the one-step sample than the two-step one. The different extent of the water absorbency and the thermosensitivity between both samples is discussed in terms of location of grafted chains in the film substrate, which was determined by electron probe microanalysis and attenuated total reflection–infrared measurements, and monomer sequence distribution of the grafted chains. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2057–2064, 1998 相似文献
999.
Hiromitsu Taniguchi Hitoshi Sugimoto Shigeru Yokoyama 《Electrical Engineering in Japan》1997,119(1):17-23
In order to clarify the cause of lightning outages of a distribution line, simultaneous observation of lightning discharge channels and types of damage on distribution lines were carried out with still cameras from July 1993 through July 1995. High-voltage lines located in the observation area did not suffer from induced voltages due to indirect lightning strikes, even if such lightning strikes were nearby. One instance of a direct lightning strike on a distribution line was observed. The striking point was the span center of the overhead ground wire, and only a transformer fuse was blown on the high-voltage line. Damage to surge arresters was observed in the case of a lightning strike on a building located near a distribution line. The cause is thought to have been lightning current which flowed into the nearby distribution line through the damaged arresters. © 1997 Scripta Technica, Inc. Electr Eng Jpn 119(1): 17–23, 1997 相似文献
1000.
Yoshibumi Yamagata Yoshinori Terasawa Hitoshi Mizoguchi Isao Hioki Takeshi Yokota Soji Kojima Hisatoshi Ikeda 《Electrical Engineering in Japan》1997,119(4):12-21
In Japan, construction of 1000 kV (UHV) transmission lines is planned in order to deal with the expected increase of electric power demand. On the line, after the fault current is interrupted by circuit breakers, the arc caused by electrostatic induction current remains for a long time because of its high voltage. To re-energize the fault line after arc extinction, a new circuit breaker reclosing system which has high-speed grounding switches (HSGS) installed at both ends of the line is employed. If, while the HSGS is interrupting an electromagnetic induction current, a ground fault takes place in another energized line, causing a shirt-circuit current including a dc component to flow, the large dc component is superimposed on the HSGS current, producing a zero shifting state with no passage through the zero point for long time. Such zero shifting durations are estimated to be up to about 80 ms. Therefore HSGS are required to interrupt this delayed zero current as a special duty. This requirement is met by a newly developed puffer interrupting chamber allowing a long pressure rise by optimizing the exhaust and residual volume of the puffer cylinder and utilizing the effect of pressure rise due to the arc. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(4): 12–21, 1997 相似文献