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991.
Water Resources Management - Based on the data series location water, Yellow River water, and the South-to-North Water Diversion water which were obtained from 1985 to 2017 in Zhengzhou, China, a... 相似文献
992.
993.
Luo Yang Chen Yiping Kim Chang Nyung 《Journal of Mechanical Science and Technology》2021,35(10):4489-4502
Journal of Mechanical Science and Technology - The understanding of magnetohydrodynamic phenomena associated with the flow of electrically-conducting fluid in complex ducts is important and... 相似文献
994.
Lian-Xin Peng Li-Juan Wei Qian Yi Gui-Hua Chen Zhen-Dong Yao Zhu-Yun Yan Gang Zhao 《International Journal of Food Science & Technology》2019,54(6):2209-2218
The effects of various flavonoids of Tartary buckwheat (rutin-enhanced flavonoid extract [REFE and quercetin-enhanced flavonoid extract [QEFE]) and individual flavonoids (rutin, quercetin and kaempferol) on the antioxidant activity, inhibition of α-glucosidases and α-amylase and starch digestibility were evaluated. Quercetin possessed the highest antioxidant activity and inhibition of α-glucosidases and α-amylase activity followed by kaempferol and rutin. REFE and QEFE have similar antioxidant and inhibition of α-amylase activities, but QEFE has much higher α-glucosidases inhibition than REFE. Tartary buckwheat flour has the lowest content of rapidly digestible starch and predicted glycaemic index (pGI) compared to maize flour, wheat flour and rice flour. Addition of rutin and quercetin to wheat flour showed a weak or no effect on digestion inhibition, but they inhibited starch digestion under solid complex conditions. Our results may help explain the benefits of supplementing the diet with food rich in flavonoids. 相似文献
995.
Zhanhui Peng Pengfei Liang Bi Chen Yichen Xiang Hui Peng Di Wu Xiaolian Chao Zupei Yang 《Ceramics International》2019,45(9):11899-11904
The molten salt method was adopted in this work to synthesize CdCu3Ti4O12 precursor powders and was found capable of notably reducing the sintering temperature. It was also found that the grain size gradually increases and the grain shape changes from spherical to cubic with increasing proportions of molten salt. The optimal sintering conditions were found to be at approximately 730?°C with the addition of 20% molten salt. After further sintering at 975?°C, the obtained perovskite ceramics exhibited a high dielectric constant at low frequencies. 相似文献
996.
997.
998.
999.
Alicia Li Jen Keow Amy Mayhall Marzia Cescon Zheng Chen 《International Journal of Hydrogen Energy》2021,46(1):837-851
Metal hydride (MH) hydrogen storage is used in both mobile and stationary applications. MH tanks can connect directly to high-pressure electrolyzers for on-demand charging, saving compression costs. To prevent high hydrogen pressure during charging, hydrogen generation needs to be controlled with consideration for unknown disturbances and time-varying dynamics. This work presents a robust control system to determine the appropriate mass flow rate of hydrogen, which the water electrolyzer should produce, to maintain the gaseous hydrogen pressure in the tank for the hydriding reaction. A control-oriented model is developed for MH hydrogen storage for control system design purposes. A proportional-integral (PI) and an active disturbance rejection control (ADRC) feedback controllers are investigated, and their performance is compared. Simulation results show that both the PI and ADRC controllers can reject both noises from the output measurements and unknown disturbances associated with the heat exchanger. ADRC excels in eliminating disturbances produced by the input mass flow rate, maintaining the pressure of the tank at the charging pressure with little oscillations. Additionally, the parameters estimated by the ADRC's extended state observer was used to predict the state-of-charge (SOC) of the MH. 相似文献
1000.
Wei-Hsin Chen Zong-Lin Tsai Min-Hsing Chang Siming You Pei-Chi Kuo 《International Journal of Hydrogen Energy》2021,46(31):16717-16733
For proton exchange membrane fuel cells (PEMFCs), the distribution of reactant streams in the reactor is critical to their efficiency. This study aims to investigate the optimal design of the inlet/outlet flow channel in the fuel cell stack with different geometric dimensions of the tube and intermediate zones (IZ). The tube-to-IZ length ratio, the IZ width, and the tube diameter are adjusted to optimize the geometric dimensions for the highest pressure uniformity. Four different methods, including the Taguchi method, analysis of variance (ANOVA), neural network (NN), and multiple adaptive regression splines (MARS), are used in the analyses. The results indicate the tube diameter is the most impactive one among the three factors to improve the pressure uniformity. The analysis suggests that the optimal geometric design is the tube-to-IZ length ratio of 9, the IZ width of 14 mm, and the tube diameter of 9 mm with the pressure uniformity of 0.529. The relative errors of the predicted pressure uniformity values by NN and MARS under the optimal design are 1.62% and 3.89%, respectively. This reveals that NN and MARS can accurately predict the pressure uniformity, and are promising tools for the design of PEMFCs. 相似文献