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81.
CH Chouard 《Canadian Metallurgical Quarterly》1997,181(2):275-86; discussion 286-7
We designed a 7-filter digital auditory prosthesis table prototype. For each of these filters frequency band width, amplification and compression were programmable in order to adapt these parameters to the deaf patient's audiometric particularities. We compared the hearing improvement it was possible to obtain with our prototype as a function of the number of filters (3, 4 or 7) and their frequency band width programmability. We tested 21 patients suffering from middle or severe neurosensory hearing loss. This study allows to demonstrate that a 7 programmable-width-filter strategy seems to be the most appropriate. 相似文献
82.
Jih-Sheng Lai 《Industrial Electronics, IEEE Transactions on》1997,44(1):71-80
This paper summarizes recently developed soft-switching inverters and proposes two possible options for electric propulsion motor drive applications. The newly developed soft-switching inverter employs an auxiliary switch and a resonant inductor per phase to produce a zero voltage across the main switch, so that the main switch can turn-on at the zero-voltage condition. Both the auxiliary switch and the resonant inductor are operating at a fractional duty and, thus, are small in size as compared to the main inverter circuit components. Operation modes in a complete zero-voltage switching cycle for the single-phase soft-switching inverter are described in detail, with graphical explanations. The circuit operation was first verified by a computer simulation, and then further tested with a 1 kW single-phase and a 100 kW three-phase inverter. Both simulation and experimental results are presented to show the superior performance in efficiency improvement, EMI reduction and dv/dt reduction of the proposed soft-switching inverters 相似文献
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S Janciauskiene O al Rayyes CH Floren S Eriksson 《Canadian Metallurgical Quarterly》1997,57(4):325-335
The frequent occurrence of hypocholesterolaemia following inflammatory processes is well known but unexplained. Elevated plasma levels of serine proteinase inhibitors (serpins) and their complexes with target enzymes have been demonstrated in inflammatory, malignant and infectious diseases which are also often accompanied by low plasma cholesterol levels. Under inflammatory conditions, uncomplexed, but cleaved inactive serpins arising from slow deacylation of the serpin-proteinase complex may be present in the circulation. To determine the influence of native and cleaved forms of serpins, such as alpha-1-antitrypsin (AAT), on lipoprotein metabolism, we investigated the effect of these forms on low density lipoprotein (LDL) catabolism in human HepG2 cell line. We have found that the cleaved form of AAT in concentrations from 125 to 2000 nmol l-1 stimulates LDL binding to the HepG2 cells, by up to 49% with a subsequent increase in LDL uptake and degradation of up to 79 and 65% respectively. Native AAT was also found to increase LDL binding and internalization by 20-25%, independently of the amount of AAT added, an effect most probably due to the cleaved form of AAT produced by local proteolysis of native AAT incubated in the cell culture. Moreover we have shown that the cleaved form of AAT interacts with LDL in vitro, and that such an interaction abolishes AAT ability to stimulate LDL binding and internalization. This study for the first time describes the ability of the cleaved form of AAT to stimulate LDL binding and internalization in HepG2 cell culture, and provides evidence that hypocholesterolaemia occurring during inflammatory processes may be mediated by cleaved forms of serpins. 相似文献
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Ming-Ching Lee Chan-Ji Lai Jan-Mou Leu William J. Plant William C. Keller Ken Hayes 《Flow Measurement and Instrumentation》2002,13(5-6):265-270
This article describes a non-contact method for measuring surface velocity and discharge in a natural channel. The X-band pulse (9.36 GHz) radar, developed by the Applied Physics Laboratory of the University of Washington, was used to scan instantaneously the lateral distribution of surface velocity across a river section, according to Bragg scattering from short waves produced by turbulent boils on the surface of the river. Based on the assumption that the vertical velocity distribution follows a universal power or logarithmic law, the discharges were estimated. 相似文献
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