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排序方式: 共有93条查询结果,搜索用时 15 毫秒
1.
Shinya Yamakawa Shela Aboud Marco Saraniti Stephen M. Goodnick 《Journal of Computational Electronics》2003,2(2-4):481-485
A fast full-band device simulator for wurtzite and zincblende GaN using a Cellular Monte Carlo (CMC) approach is reported for wurtzite and zincblende GaN. The full-phonon dispersion relationship including anisotropic polar-optical phonon scattering is taken into account for the wurtzite GaN calculation. In the bulk simulation, the CMC model is about 30–100 times faster than the conventional Ensemble Monte Carlo model at high electric field region. This CMC model is applied to the simulator of MESFET devices, and the calculation speed is significantly improved. 相似文献
2.
J.S. Ayubi-Moak S.M. Goodnick S.J. Aboud M. Saraniti S. El-Ghazaly 《Journal of Computational Electronics》2003,2(2-4):183-190
In this work we utilize the Finite-Difference Time Domain (FDTD) Method coupled to a full band, particle-based simulator to solve for the total Lorentz force. Replacing a traditional Poisson solver with a more robust electromagnetics (EM) solver allows us to accurately account for radiated losses and provides a useful tool for investigating the near and far-field radiation patterns inherent in modern devices. 相似文献
3.
Yong-Seo Park Seong-Gook Kang Alma Leticia Martinez Ayala Olga Martín-Belloso Shela Gorinstein 《LWT》2006,39(7):748-755
Fresh persimmons were subjected to two different processes: sun-drying during 1 month and dehydration at 60 °C during 12 h. To assess the effect of this process on nutritional and health-related properties of persimmons dietary fibers, minerals, trace elements, polyphenols and the total radical scavenging activities (TRSAs) were determined before and after processing. It was found that the contents of dietary fibers, minerals and trace elements in fresh and dried persimmons fruits were comparable. Total polyphenols in fresh persimmons was higher than in dried fruits (1.3 vs. 0.9 and 0.8 mg/100 g FW, respectively) and percentage of inhibition was higher than in dried fruits (70% vs. 59% and 55% and 58% vs. 53% and 46% for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) [ABTS] radicals, respectively (P>0.05 in all cases). In conclusion: (1) the differences in the contents of dietary fibers, minerals and trace elements in fresh and dried persimmons are not significant; (2) the contents of polyphenols and the level of the TRSA are higher in fresh persimmons than in dried fruits; however, both variables are also high in dried persimmons; (3) when fresh fruits are not available, proper dried persimmons could be used as a valuable substitute. 相似文献
4.
J. Branlard S. Aboud S. Goodnick M. Saraniti 《Journal of Computational Electronics》2003,2(2-4):213-217
The goal of this contribution is to use a three dimensional (3D) full-band particle-based simulator to investigate 3D scaling effects of static and dynamic current-voltage characteristics of GaAs MESFET structures. The full-band particle-based simulator is also applied to a novel dual-gate GaAs MESFET structure. 相似文献
5.
基于DOE和遗传算法的传动系参数优化方法研究 总被引:1,自引:0,他引:1
研究了以经济性为目标的动力传动优化方法,利用试验设计和遗传优化算法,针对特定的驾驶循环,在不降低驾驶性能的前提下,寻求最佳的经济性匹配参数.计算结果表明,采用DOE与GA分析相结合的方法,不仅可以大幅缩减试验样本容量和仿真时间,亦可达到令人满意的效果.通过优化匹配,该矿用车的燃油消耗量下降了6.19%. 相似文献
6.
The suspension system is a key element in motor vehicles. Advancements in electronics and micropro- cessor technology have led to the realization of mechatronic suspensions. Since its introduction in some production motorcars in the 1980s, it has remained an area which sees active research and development, and this will likely continue for many years to come. With the aim of identifying current trends and future focus areas, this paper presents a review on the state-of-the-art of mechatronic suspensions. First, some commonly used classifications of mechatronic suspensions are presented. This is followed by a discussion on some of the actuating mechanisms used to provide control action. A survey is then reported on the many types of control approaches, including look-ahead preview, predictive, fuzzy logic, proportional-integral-derivative (PID), optimal, robust, adaptive, robust adaptive, and switching control. In conclusion, hydraulic actuators are most commonly used, but they impose high power requirements, limiting practical realizations of active suspensions. Electromagnetic actuators are seen to hold the promise of lower power requirements, and rigorous research and development should be conducted to make them commercially usable. Current focus on control methods that are robust to suspension parameter variations also seems to produce limited performance improvements, and future control approaches should be adaptive to the changeable driving conditions. 相似文献
7.
Glucosinolates (GLS), antioxidative compounds, total radical scavenging activities (TRSAs) and proteins of white cabbage samples derived from different regions of Europe, collected in the spring and autumn, were studied. Glucobrassicin and sinigrin were the dominating GLS in all analyzed cabbage samples. Depending on origin, these two GLS accounted for ∼30% to ∼70% of the total. The total GLS content ranged from 3.3 to 7.7 μmol/g dw in lyophilized vegetables. Assays based on electron transfer [total phenols by Folin-Ciocalteu reagent (FCR), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] radical cation (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)] were used to compare the TRSAs and the main bioactive compounds in cabbage. Total polyphenols varied from 2.4 to 4.9 GAE/g dw. The TRSAs ranged from 2.7 to 8.2 μmol TE/g dw in ABTS test and from 2.4 to 5.4 μmol TE/g dw in DPPH assay. The maximum amount of polyphenol compounds, antioxidant activity, as well as total GLS content, were recorded in Belgian cabbage harvested in the autumn and the lowest ones were found for Poland 2 cabbage harvested in the spring. In extracted and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) proteins from cabbage leaves only in samples from England and Belgium some differences in patterns were found in the regions of 60 and 97 kDa. The calculated correlations between antioxidative potency and the abundance of bioactive compounds were highly statistically significant. This suggests that TRSA could serve as a means of standardization of natural mixtures, at least in the case of cabbage, necessary to compare results of biological studies carried out for vegetable derived samples. 相似文献
8.
Examined developmental differences in emotional expression. It is suggested that there are cognitive and character structures that may be prerequisites for certain adult reactions to painful life events. The self-denigrating adult may be a discrepancy between self-representation and ideal self. In a child, these structures may not yet be stable enough to withstand such critical self-appraisal. 35 5- and 7-yr-olds were asked to give liking ratings to hypothetical children who had undergone a painful life event and to give evaluative ratings of themselves in the same situations. Older Ss evaluated a hypothetical other and themselves negatively, whereas the 5-yr-olds could not extend their negative evaluation of a sad other to themselves. Results are discussed in terms of developmental changes in the depressive reaction. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Anthocyanins,total polyphenols and antioxidant activity in amaranth and quinoa seeds and sprouts during their growth 总被引:8,自引:0,他引:8
Paweł Paśko Henryk Bartoń Paweł Zagrodzki Shela Gorinstein Maria Fołta Zofia Zachwieja 《Food chemistry》2009
Total antioxidant capacity, total phenolic contents (TP) and anthocyanins contents (ANT) were determined in Amaranthus cruentus and Chenopodium quinoa seeds and sprouts. Antioxidant activity of the investigated seeds decreased in the following order: quinoa, amaranth v. Rawa, amaranth v. Aztek for FRAP and quinoa, amaranth v. Aztek, amaranth v. Rawa for both ABTS and DPPH. Sprouts activity depended on the length of their growth, and the peak values were reached on the fourth day in the case of amaranth and on the sixth day in the case of quinoa. The data obtained by the three methods showed significant correlation between TP content in seeds and sprouts. In sprouts grown in the daylight and in the darkness we observed some significant changes of TP, ANT and antioxidant activity. Amaranth and quinoa seeds and sprouts can be used in food, because it is a good source of ANT and TP with high antioxidant activity. 相似文献
10.
Myang Hee Im Hanna Leontowicz Jacek Namiesnik Seong-Gook Kang Shela Gorinstein 《LWT》2011,44(1):92-99
This research was performed in order to compare the water and acetone extracts of raw and boiled for 10, 20, 40 and 60 min Korean lotus roots (KLR) and Polish white onion (PWO) in the contents of their bioactive compounds, antioxidant activity and thermostability.It was found that polyphenols (mg GAE/g), flavanols (μg GAE/g), flavonoids (mg CE/g), anthocyanins (mg CGE/kg) and tannins (mg CE/g) in water extract of raw lotus roots were 14.18 ± 0.7, 8.41 ± 0.5, 1.09 ± 0.06, 21.3 ± 1.2 and 7.29 ± 0.4, and of white onion - 11.11 ± 0.6, 6.78 ± 0.3, 0.71 ± 0.03, 17.00 ± 0.9 and 1.64 ± 0.08, respectively, and significantly higher in KLR (P < 0.05). The antioxidant activity of raw KLR water extract (139.4 ± 6.1, 53.1 ± 3.6 and 89.3 ± 4.6 μmol TE/g for DPPH, CUPRAC and ABTS, respectively) was significantly higher than in white onion (23.84 ± 1.8, 31.9 ± 2.1 and 38.14 ± 2.6 for DPPH, CUPRAC and ABTS, respectively, P < 0.05).The thermostability of the water KLR extract’s of polyphenols, flavanols, flavonoids, anthocyanins and tannins was high and even after 60 min of boiling remains as 40.0, 42.3, 50.5, 41.4 and 41.0%, respectively. After 60 min of boiling the most thermostable compounds were flavonoids - remaining at 50.5% in water extract of KLR. Also after 60 min of boiling the thermostability of the antioxidant activity of water extracts of KLR remained significantly high: 40.6, 42.3, 46.3 and 43.6%, according to DPPH, FRAP, ABTS and CUPRAC assays, respectively.Similar relationship was obtained with acetone extracts, but the value was lower than with the water ones. In conclusion, the contents of some bioactive compounds, the antioxidant activity and the thermostability in water and acetone extracts of KLR are significantly higher than the same indices in PWO. FTIR and fluorimetry can be used as additional markers for the characterization of bioactive compounds in vegetables. 相似文献