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1.
A fault section detection system that uses optical magnetic field sensors and instantly detects the section in which a ground fault occurred was developed for 66 kV underground multiterminal systems having Y-branch joint boxes. The optical magnetic field sensor, which is based on the Faraday effect in Bi-doped YIG ((BiYbGd)3Fe5O12) having a large Verdet constant, detects cable conductor currents of 0 to 2000 A with high precision with the use of a laminated magnetic ring core of silicon steel plates. Sensors and a fault section detector/indicator of a system are connected with optical fibers capable of nonrepeated transmission of over 6 km  相似文献   
2.
The objectives of the present study were to investigate autonomic nervous system influence on heart rate during physical exercise and to examine the relationship between the fractal component in heart rate variability (HRV) and the system's response. Ten subjects performed incremental exercise on a cycle ergometer, consisting of a 5-min warm-up period followed by a ramp protocol, with work rate increasing at a rate of 2.0 W/min until exhaustion. During exercise, alveolar gas exchange, plasma norepinephrine (NE) and epinephrine (E) responses, and beat-to-beat HRV were monitored. HRV data were analyzed by "coarse-graining spectral analysis" (Y. Yamamoto and R. L. Hughson. J. Appl. Physiol. 71: 1143-1150, 1991) to break down their total power (Pt) into harmonic and nonharmonic (fractal) components. The harmonic component was further divided into low-frequency (0.0-0.15 Hz) and high-frequency (0.15-0.8 Hz) components, from which low-frequency and high-frequency power (Pl and Ph, respectively) were calculated. Parasympathetic (PNS) and sympathetic (SNS) nervous system activity indicators were evaluated by Ph/Pt and Pl/Ph, respectively. From the fractal component, the fractal dimension (DF) and the spectral exponent (beta) were calculated. The PNS indicator decreased significantly (P < 0.05) when exercise intensity exceeded 50% of peak oxygen uptake (VO2 peak). Conversely, the SNS indicator initially increased at 50-60% VO2peak (P < 0.05) and further increased significantly (P < 0.05) at > 60% VO2peak when there were also more pronounced increases in NE and E.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
3.
We have characterized the electronic structure of FeSe1−xTex for various x values using soft x-ray photoemission spectroscopy (SXPES), high-resolution photoemission spectroscopy (HRPES) and inverse photoemission spectroscopy (IPES). The SXPES valence band spectral shape shows that the 2 eV feature in FeSe, which was ascribed to the lower Hubbard band in previous theoretical studies, becomes less prominent with increasing x. HRPES exhibits systematic x dependence of the structure near the Fermi level (EF): its splitting near EF and filling of the pseudogap in FeSe. IPES shows two features, near EF and approximately 6 eV above EF; the former may be related to the Fe 3d states hybridized with chalcogenide p states, while the latter may consist of plane-wave-like and Se d components. In the incident electron energy dependence of IPES, the density of states near EF for FeSe and FeTe has the Fano lineshape characteristic of resonant behavior. These compounds exhibit different resonance profiles, which may reflect the differences in their electronic structures. By combining the PES and IPES data the on-site Coulomb energy was estimated at 3.5 eV for FeSe.  相似文献   
4.
The prevalence of Campylobacter (>90%) and Salmonella (33%) in turkeys at slaughter has been estimated. This report describes studies to estimate the time of entry of Campylobacter and Salmonella into the brooder house, which is the first stage of commercial turkey production. In trial 1, birds (∼100 per time point) were monitored by conventional culture at three intervals (0, 9, and 16 days of age). Campylobacter spp. were not detected in poults at the day of hatch; Salmonella was isolated from the ceca (3.9%) and yolk sac (0.1%). By day 9, Salmonella were frequently isolated from the ceca (55%) and small intestine (45%) while Campylobacter was not cultured. By day 16, the prevalence of Salmonella in the ceca (21%) and small intestine (5.1%) had declined; Campylobacter was infrequently isolated from either the ceca (2%) or small intestine (3%). In trial 2, poults (50 per time point at 5, 20, and 33 days of age) were monitored for Campylobacter and Salmonella by real-time polymerase chain reaction (PCR); Salmonella was also monitored by conventional culture. Whereas Campylobacter was not detected by real-time PCR in the ceca of 5-day-old birds, it was detected on days 20 (92%) and 33 (90%). In contrast, Salmonella was isolated from young birds at days 5 (98%), 20 (98%), and 33 (98%), after which time the turkeys were moved to the finisher house. At slaughter at 138 days, Salmonella prevalence in the ceca had declined (4.5%) in contrast to the prevalence of Campylobacter (92%). Antimicrobial sensitivity profiles of the Salmonella isolates indicated an increase of sulfonamide-resistant isolates throughout the brooder stage. Genotyping by pulsed-field gel electrophoresis analysis of Salmonella (45 isolates per sampling time) indicated fluctuating populations as the birds matured.  相似文献   
5.
针对医疗仪器和电焊机等市场领域对中高频开关应用的需求,三菱电机开发了NFM系列中高频IGBT模块。本文分析了电流谐振逆变器在两种不同工作模式下的波形和特征,然后详细介绍了NFM系列模块设计中采用的关键技术,包括IGBT硅片、超高速续流二极管(Free Wheeling Diode,简称FWD)、低电感封装技术等,并指出这种模块在中高频开关应用时在低损耗方面的优越性。  相似文献   
6.
7.
 To design contact-type gimbal system for a newly developed removable flexible disk drive called Card size flexible disk drive (CFDD) (Shinpuku et al., 2001; Ryoson et al., 2001), the gimbal's vibration characteristics in the disk-rotation direction were measured and simulated using FEM. To determine the relationship between vibration and friction in the head disk interface (HDI), a hard disk was also used. The friction characteristics were inserted into the FEM model based on the results. The gimbal was modified to suppress vibration amplitude to half in both simulation and experiment. Received: 5 July 2001/Accepted: 1 November 2001 Paper presented at the 12th Annual Symposium on Information Storage and Processing Systems, Santa Clara, CA, USA, 28–29 June, 2001.  相似文献   
8.
This paper is concerned with systematic developments of the Fraunhofer-diffraction method for studies of plasma density fluctuations in high-temperature plasmas using infrared lasers, namely (i) development of the general theory of the Fraunhofer-diffraction method, (ii) measurements of fluctuations propagating in an azimuthal direction, (iii) measurements of fluctuation intensities, and (iv) application in measurements on high-temperature plasmas.  相似文献   
9.
In resistance training, it has been empirically accepted that muscle hypertrophy is developed by low intensity and high volume training, while muscle strength and power are developed by high intensity and low volume training. The purpose of the present study was to investigate the influence of two different modes of resistance training on isokinetic strength and muscle cross-sectional area (CSA) in females. Eleven females, who had no experience in resistance training, participated in this study and were randomly divided into two groups. The former consisted of 4-5 sets of 15-20 RM (repetition maximum) with sufficient rest between sets (Group H), while the latter consisted of 8-9 sets of 4-6R M with 90 s of rest between sets (Group S). The former was assumed to be appropriate for muscle hypertrophy and the latter muscle strength, respectively. All subjects completed isotonic knee extension exercise three times a week for 8 weeks. Measurements were made on quadriceps muscle cross-sectional area (CSA) and isokinetic torques at 0, 60, 180, and approximately 300 degrees before training, at the fifth week and the end of training period. Muscle CSA was defined as the sum of CSA measured at 30, 50 and 70% of femur length. After training, muscle CSA had significantly increased in both groups: 3.3 +/- 0.7% (p < .05) for group H and 3.6 +/- 1.1% (p < .05) for group S, respectively. While the changes in isokinetic torque were 43.4 +/- 47.5% (p < .05) for group H and 27.4 +/- 31.3% (p < .05) for group S, respectively. In both groups the percentage changes of the isokinetic strength were significantly higher than those of the CSA. No significant difference in these variables were found between the two groups. These results suggest that during the early phase of resistance training two different modes of resistance training may have similar effects on muscle CSA and isokinetic strength in untrained females.  相似文献   
10.
A liver transplant patient who developed renal failure postoperatively was treated using continuous hemodiafiltration (CHDF). Doses ranging from 0.01 to 0.06 mg/kg/day of FK-506 had been administered intravenously. FK-506 concentrations before and after the filter, and in the ultradiafiltrate were 45.3 +/- 2.9, 56.0 +/- 5.3, and 9.1 +/- 3.1 ng/ml (mean, +/- S.D.), respectively. The filtration rate was 23.6 +/- 6.4%, and extracted FK-506 amounted to 522.0 micrograms (11.3% of administered dose). A part of the FK-506 administered was eliminated through the filter during CHDF.  相似文献   
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