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11.
Yasuo Cho Teruaki Kasahara Koichi Fukuda 《Journal of the American Ceramic Society》1999,82(7):1720-1724
Two-dimensional images of the distribution showing the temperature coefficient of the dielectric constant for two types of two-phase composite ceramics composed of TiO2 -Bi2 Ti4 O11 and BaTi4 O9 -BaPr2 Ti4 O12 were obtained using scanning photothermal dielectric microscopy. The images of the TiO2 -Bi2 Ti4 O11 ceramic showed that the TiO2 and Bi2 Ti4 O11 grains had negative and positive temperature coefficients, respectively, and that the macroscopic averaged temperature coefficient of the ceramic was relatively low because of the cancellation of the opposite signs of the coefficients. On the other hand, the images of the BaTi4 O9 -BaPr2 Ti4 O12 ceramic showed that the temperature coefficient of both grains had the same sign (negative), although their absolute values were quite different. 相似文献
12.
A self-consistent simulation using the Monte Carlo ensemble particle technique for analysis of heterojunction bipolar transistor (HBT) transient behavior, such as switching performance, is presented. The transient Monte Carlo method has been applied to a self-consistent simulation of two HBT designs with improved collector structures for high-speed and high-frequency applications, and the results are compared with the characteristics of conventional HBTs. The simulation results indicate that the two new collector structures, the inverted field collector and the undoped collector, have better switching performance than the conventional HBT. The study of the switching characteristics' dependence on collector-base bias voltage and collector current suggests that the inverted field HBT is the best approach in terms of switching properties. The results are supported and explained by examining electron transport properties such as overshoot velocity and energy valley occupation, as well as band bending in the collector space-charge region at different current levels 相似文献
13.
K Kobayashi M Endo H Nishida Y Tomizawa H Satoh H Koyanagi 《Canadian Metallurgical Quarterly》1998,46(9):878-881
The extramammary Paget's disease of anogenital area is rare, and is seen as a precancerous lesion or carcinoma in situ. In most cases, surgical treatment including dissection of regional lymph nodes, skin resection and grafting should be considered first. A 74-year-old male suffered from effort angina and underwent triple coronary artery bypass grafting (CABG) including saphenous vein graft (SVG) harvested from right lower leg. Five years previously he underwent skin grafting for extramammary Paget's disease of both inguinal areas and the perineal area. The postoperative course was uneventful and he was discharged 23 days after the CABG operation. Extramammary Paget's disease is localized in epidermis for years and there has been no report of direct invasion into vessels. Therefore, there appears to be no reason not to use an SVG if there is no luminal thrombus or occlusion. 相似文献
14.
Takashi Ogihara Manabu Iizuka Teruaki Yanagawa Nobuo Ogata Kokichi Yoshida 《Journal of Materials Science》1992,27(1):55-62
A reactor system, which continuously hydrolysed the metal alkoxide in an alcohol solution, was designed using an electromagnetic
stirrer and an ageing tube. Several monosized colloidal particles were produced by this reactor system, which had high reproducibility
and reliability for long-term production. The relation between powder characteristics and experimental parameters such as
reagent concentration, mixing rate, ageing time, temperature, was investigated. These parameters had an effect on the particle
size, size distribution, morphology and state of agglomeration. It is possible to control the particle size to between 0.1
and 1.0 μm by varying the experimental conditions. A narrower size distribution of powders was obtained by using an electromagnetic
stirrer with greater flow rate. Physical and chemical properties of monosized colloidal particles obtained by this reactor
were comparable to those of monosized colloidal particles obtained by the batch process. 相似文献
15.
AlGaAs/GaAs ballistic collection transistors (BCTs) are investigated by self-consistent Monte Carlo simulation, focusing on the space-charge effect in the collector region. In addition to the conventional BCT collector structure (i-p+-n+), modified collector structures which have n--p+-n + and p--p+-n+ doping profiles are examined. By taking account of the fact that the collector delay time is composed of transit time and capacitance charging time, it is shown that the n--p+-n+ collector structure is effective for the suppression of the base-widening effect (Kirk effect) compared to the i-p+-n+ or p- -p+-n+ structure. Donors in the n- layer compensate for the negative space charges produced by near-ballistic electrons. For a simulated BCT with an n--p +-n+ collector, the smaller collector capacitance charging time leads to improvement in current-gain cutoff frequency under high current injection 相似文献
16.
Miyamoto Y. Kataoka T. Yonenaga K. Tomizawa M. Hirano A. Kuwahara S. Tada Y. 《Lightwave Technology, Journal of》2002,20(12):2115-2128
This paper describes recent technical challenges and the progress toward the realization of the optical transport network (OTN) based on 43 Gb/s channel. We describe the new digital frame format "OTU3: Optical Channel Transport Unit 3," which is standardized in ITU-T for OTN, for the enhancement of the network management capability in the OTN based on 43-Gb/s channels. We first proposed 43-Gb/s/ch dense wavelength-division multiplexing (DWDM) dispersion-managed transmission system using carrier-suppressed return-to-zero (CS-RZ) format that has several attractive features; it advances the evolution of OTN into 100 GHz-spaced long-haul DWDM transport networks. The first wavelength-division multiplexing (WDM) field trials confirmed the superiority of CS-RZ format in the DWDM transmission performance for the first time. The first 1 Tb/s (25 /spl times/ 43 Gb/s) WDM field trial confirmed the excellent network management capability of OTU3 in future data-centric OTN using the newly developed 43-Gb/s OTN line-terminal prototype. 相似文献
17.
Hiroyuki Usui Ousuke Miyamoto Teruaki Nomiyama Yuji Horie Tomoyuki Miyazaki 《Solar Energy Materials & Solar Cells》2005,86(1):123-134
The film electrodes of TiO2, which have two functions of opto-electric conversion and storage of electrochemical energy, were prepared by pulsed laser deposition. To investigate the relationship between the photo-rechargeability and the surface structure, the TiO2 film electrodes with different surface morphology were prepared by changing the inert gas pressure during the deposition. The photo-charged quantity was found to be proportional to the third power of the rms of surface roughness. The results suggest that not only the surface but also the interstices between crystal grains near the surface contribute to the photo-charging with low photo-emf. 相似文献
18.
Kobayashi M Ohtsuka K Tamura Y Tomizawa S Kamijo K Iwakoshi K Kageyama Y Nagayama T Takano I 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2011,52(2):121-129
A survey of pesticide residues in 595 imported frozen products on the Tokyo market from April 1989 to March 2008 was carried out. Forty three kinds of pesticides, including organophosphorus, organochlorine, carbamate, pyrethroid and others, were detected between levels of trace (below 0.01 ppm) and 4.6 ppm from 162 samples. Chlorpyrifos, cypermethrin and omethoate were frequently detected in green vegetables (komatsuna leaf and spinach), cypermethrin and methamidophos were detected in pods and seeds (green soybean and string pea), chlorpropham (CIPC) was detected in potato, and captan and carbaryl were detected in berries (blueberry, raspberry and strawberry). The hydrophilic pesticide methamidophos was detected in flesh of lychee. Residue levels of these pesticides were calculated as between less than 0.5% and 30% of their ADI values according to the daily intake of frozen products. Therefore, these frozen products should be safe when they were eaten in customary amounts. 相似文献
19.
20.
Seismic electromagnetic (EM) phenomena have been observed at many laboratories with specially designed systems. Recently we can utilize radio receivers, personal computers, and communication systems with higher performances and reasonable cost. It is possible to observe seismic EM phenomena not only by specially designed systems but also by a simple observation system integrated by these devices and systems. We have created an observation system for seismic EM phenomena with them in the very high frequency (VHF) band, from 76 MHz to 90 MHz, assigned for FM broadcasting exclusive use in Japan. We are surrounded by many EM waves, such as broadcasting, communication usage, and man‐made noises. Thus, we have newly developed the dual frequency observation method. In this paper, we describe an observation method that can identify whether a received signal is a broadband EM wave or an artificial FM radio wave. Next, the observation results for broadband EM waves from galactic noise and solar flares are presented. Then, the observation results for FM radio waves reflected from sporadic E layer and the Leonid meteors are shown. Finally, the observation results for the detected broadband EM waves associated with the Geiyo earthquake are described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 36–44, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20350 相似文献