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排序方式: 共有530条查询结果,搜索用时 16 毫秒
41.
Effect of a Short‐Time Germination Process on the Nutrient Composition,Microbial Counts and Bread‐Making Potential of Whole Flaxseed 下载免费PDF全文
42.
An IC containing four clock deskew buffers using the delay-locked-loop technology has been fabricated in a 0.6 μm single poly double metal CMOS process. The core chip area is 0.9×0.9 mm 2. The maximum operating frequency is 80 MHz, and the total power dissipation of the four deskew buffers is 59 mW for a 3 V supply voltage. The maximum clock skew after deskewing is less than 300 ps, and the peak-to-peak clock jitter is less than 170 ps. The deskew range is 0.5-3.8 ns 相似文献
43.
Ta‐Peng Tsao John Robert Smith Christopher John Cudworth Peter William Rush 《中国工程学刊》2013,36(4):473-483
Abstract The computer prediction of turbogenerator behaviour following fault or disturbance conditions has become an important feature in the assessment of machine system design, pre‐commissioning test appraisals, system operational procedures, machine monitoring strategy and post‐event damage diagnoses. In this paper computer methods are described to assess the comparative severity of various electrical faults and disturbances, the effect of specific operational practices together with the prediction of peak torsional transient behaviour. This paper is supported by realistic examples simulating the transient behaviour of a number of generational units. 相似文献
44.
Wei-Chan Chen Kun-Ling Wu Biing-Hwa Yan Man-Chin Tsao 《The International Journal of Advanced Manufacturing Technology》2013,69(5-8):1791-1801
The spiral polishing mechanism employed a fast turning screw rod to drive the abrasive for workpiece surface polishing. In this study, the powerful ring magnet installed around the workpiece would attract the self-developed magnetic hot melt adhesive particles (MHMA particles) during the process of polishing, driving the SiC particles against the workpiece, the inner wall of the bore. At the same time, the flexibility of MHMA particles helped improve the surface quality of the bore by preventing the SiC particles from heavily scratching it. The effects of magnetic flux density, size and concentration of SiC particles, concentration of MHMA particles, viscosity of silicone oil, revolution speed of the spindle as well as machining time and machining gap on operation temperature, slurry viscosity, surface roughness, and material removal were discussed and the best parameter combination was identified based on the results of the experiment. The effects of each machining parameter on the finished surface topography of the workpiece were also examined. Both analysis of variance and F-test indicated that magnetic flux density and the concentration of MHMA particles were the two most important variables affecting the surface roughness. In other words, magnetic force helped improve spiral polishing. Furthermore, the results showed that adding new MHMA particles to the slurry greatly improved the surface quality, at a rate of 90 %, and reduced the workpiece surface roughness from 0.9 μm down to 0.094 μm. 相似文献
45.
J. C. Leong L. C. Tsao C. J. Fang C. P. Chu 《Journal of Materials Science: Materials in Electronics》2011,22(9):1443-1449
The effects of nano-TiO2 particles on the interfacial microstructures and bonding strength of Sn3.5Ag0.5Cu composite solder joints in ball grid array
packages with immersion Sn surface finishes have been investigated. Metallography reveals that addition of nano-TiO2 particle retarded wicker-Cu6Sn5 IMC formed in the Sn3.5Ag0.5Cu composite solder joints. The thickness of the interfacial intermetallic compounds of the solder
joint was reduced with increased additions of nano-TiO2 particles (0.25–1.0 wt%), but further additions up to 1.25 wt% decreased the beneficial influence. This indicates that the
presence of a small amount of nano-TiO2 particles is effective in suppressing the growth of the intermetallic compounds layer. In addition, the shear strength of
the soldered joints was improved by larger nano-TiO2 particle additions, with the peak shear strength occurring at 1.0 wt% of nano-TiO2 particles into the Sn3.5Ag0.5Cu solder. The fracture mode also changed with increased amounts of nano-TiO2 particles. 相似文献
46.
Mariarenata Sessa Alessandro A. Casazza Patrizia Perego Rong Tsao Giovanna Ferrari Francesco Donsì 《Food and Bioprocess Technology》2013,6(10):2609-2620
Phenolic compounds were extracted from grape marc by means of high pressure and temperature extraction. In order to increase their dispersability in the aqueous phase, the polyphenolic extracts were encapsulated at a final concentration of 0.1 % (w/w) in nanoemulsion-based delivery systems, which were formulated with natural ingredients, using either a liquid (sunflower oil) or a solid (palm oil) lipid phase, as well as the combination of a hydrophilic and hydrophobic emulsifier, and were produced by high-pressure homogenization. The delivery systems were characterized in terms of physicochemical stability under accelerated ageing (storage at 4 °C, 30 °C, and 55 °C for 14 days), by recording the evolution of the mean droplet size, the creaming index as well as the UV–vis absorption spectra of the encapsulated polyphenols. The antioxidant activity of the encapsulated extracts was measured with two different chemical assays (FRAP and ORAC) and a cellular antioxidant assay. Sunflower oil-based nanoemulsions resulted to be the most physically and chemically stable, with no significant variation of the mean droplet size and no degradation of the encapsulated compounds under the different conditions tested. The FRAP and ORAC assays showed that the antioxidant compounds, when encapsulated, are as available as unencapsulated polyphenols in scavenging the peroxyl radicals (ORAC), but are less available in reducing the ferric tripyridyltriazine complexes (FRAP). Remarkably, the cellular antioxidant activity was significantly higher for the encapsulated grape marc polyphenols than for the unencapsulated ones, suggesting the fundamental role of the nanoemulsions in favoring the delivery through the biological membranes. 相似文献
47.
Adenocarcinoma of the gallbladder combined with a malignant peripheral nerve sheath tumor (MPNST) in the gallbladder in an 81-year-old woman is reported. The resected gallbladder showed two distinct tumor components, the epithelioid type of MPNST and adenocarcinoma with areas of mucin production. Although the immediate postoperative course was uneventful, a pathologic fracture of her right upper femur developed 4 months after the cholecystectomy. The pathology was determined to be a feature of metastatic MPNST rather than of adenocarcinoma. A whole body bone scan revealed multiple metastases, including the left parietal skull, left ninth rib, seventh thoracic vertebra, and right upper third of the femur. Despite cholecystectomy and postoperative irradiation therapy, she died 6 months after diagnosis of the tumor. Without an autopsy the primary site of the MPNST was unknown. We found that the prognosis was very poor in patients with distal metastatic MPNST, especially in older patients. 相似文献
48.
49.
Chun-Pang Wu Hen-Wai Tsao 《Solid-State Circuits, IEEE Journal of》2005,40(6):1249-1258
This paper describes a CMOS programmable gain amplifier (PGA) that maintains a 3-dB bandwidth greater than 110 MHz and can provide an 84-dB gain control range with 1-dB step resolution. The PGA can also be operated in a low-power mode with 3-dB bandwidth greater than 71 MHz. Integrated with this PGA is a CMOS successive logarithmic detecting amplifier with a /spl plusmn/0.7-dB logarithmic accuracy over an 80-dB dynamic range. It achieves -83-dBm sensitivity and consumes 13 mA from a single 3-V supply in the normal power mode. The chip area, including pads, occupies 1.5/spl times/1.5 mm/sup 2/. 相似文献
50.
Cheing-Hong Lin Jingshown Wu Hen-Wai Tsao Chun-Liang Yang 《Lightwave Technology, Journal of》2005,23(4):1543-1555
In this paper, we propose a family of newly constructed codes to suppress the phase-induced intensity noise (PIIN) in spectral amplitude-coding (SAC) optical code division multiple access (OCDMA) systems. These new codes are derived from modified prime codes and their cross-correlation is not larger than one. We also present a novel SAC-OCDMA system employing the new codes together with Mach-Zehnder interferometers to eliminate the multi-user interference (MUI). Compared with the systems employing modified quadratic congruence codes (MQC codes), numerical results verify that our proposed system can more effectively suppress the PIIN and eliminate MUI. Hence, the number of simultaneously users and total transmission rate increases significantly. 相似文献