The effect of Gd content ranging from 6.5 wt.%to 8.5 wt.%on microstructure evolution and dynamic mechanical behavior of Mg−xGd−3Y−0.5Zr alloys was investigated by optical microscopy,X-ray diffraction,scanning electron...The effect of Gd content ranging from 6.5 wt.%to 8.5 wt.%on microstructure evolution and dynamic mechanical behavior of Mg−xGd−3Y−0.5Zr alloys was investigated by optical microscopy,X-ray diffraction,scanning electron microscopy and split Hopkinson pressure bar.The microstructure of as-cast Mg−xGd−3Y−0.5Zr alloys indicates that the addition of Gd can promote grain refinement in the casting.Due to the rapid cooling rate during solidification,a large amount of non-equilibrium eutectic phase Mg_(24)(Gd,Y)_(5) appears at the grain boundary of as-cast Mg−xGd−3Y−0.5Zr alloys.After solution treatment at 520℃ for 6 h,the Mg_(24)(Gd,Y)_(5) phase dissolves into the matrix,and the rare earth hydrides(REH)phase appears.The stress−strain curves validate that the solution-treated Mg−xGd−3Y−0.5Zr alloys with optimal Gd contents maintain excellent dynamic properties at different strain rates.It was concluded that the variation of Gd content and the agglomeration of residual REH particles and dynamically precipitated fine particles are key factors affecting dynamic mechanical properties of Mg−xGd−3Y−0.5Zr alloys.展开更多
This paper proposes an y2-y∞ learning law as a new learning method for dynamic neural networks with external disturbance. Based on linear matrix inequality （LMI） formulation, the y2-y∞ learning law is presented to...This paper proposes an y2-y∞ learning law as a new learning method for dynamic neural networks with external disturbance. Based on linear matrix inequality （LMI） formulation, the y2-y∞ learning law is presented to not only guarantee asymptotical stability of dynamic neural networks but also reduce the effect of external disturbance to an y2-y∞ induced norm constraint. It is shown that the design of the y2-y∞ learning law for such neural networks can be achieved by solving LMIs, which can be easily facilitated by using some standard numerical packages. A numerical example is presented to demonstrate the validity of the proposed learning law.展开更多
A comparative study of cascades in nanostructured ferritic alloys and pure Fe is performed to reveal the influence of Y_2Ti_2O_7 nanocluster on cascades by molecular dynamics simulations. The cascades with energies of...A comparative study of cascades in nanostructured ferritic alloys and pure Fe is performed to reveal the influence of Y_2Ti_2O_7 nanocluster on cascades by molecular dynamics simulations. The cascades with energies of primary knock-on atom（PKA） ranging from 0.5 keV to 4.0 keV and PKA＇s distances to the interface from 0 to 50 are simulated. It turns out that the Y_2Ti_2O_7 nanocluster can absorb the kinetic energy of cascade atoms, prevent the cascade from extending and reduce the defect production significantly when the cascades overlap with the nanocluster. When the cascade affects seriously the nanocluster, the weak sub-cascade collisions are rebounded by the nanocluster and thus leave more interstitials in the matrix. On the contrary, when the cascade contacts weakly the nanocluster, the interface can pin the arrived interstitials and this leaves more vacancies in the matrix. Moreover, the results indicate that the Y_2Ti_2O_7 nanocluster keeps stable upon the displacement cascade damage.展开更多
In this paper, samples of CaO-riched MgO-CaO added with Y2O3 were prepared and the growth rate of MgO grains were investigated, and the calculation of the grain growth active energy at different temperatures was done ...In this paper, samples of CaO-riched MgO-CaO added with Y2O3 were prepared and the growth rate of MgO grains were investigated, and the calculation of the grain growth active energy at different temperatures was done for the high performance anti-hydration CaO-riched MgO-CaO clinker. It is of significance for decreasing the synthetic temperature in industry production.展开更多
The intramolecular process of Mg ( Ⅱ ) - , Sc ( Ⅲ ) - , Y ( Ⅲ ) - , In(Ⅲ)-and Pb ( Ⅱ )-trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA) complexes was studied by the method of proton dynamic NMR(DNMR). The top...The intramolecular process of Mg ( Ⅱ ) - , Sc ( Ⅲ ) - , Y ( Ⅲ ) - , In(Ⅲ)-and Pb ( Ⅱ )-trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA) complexes was studied by the method of proton dynamic NMR(DNMR). The top limit of. the experimental temperature range of deuterium oxide solutions was extended from 100℃ to 167 ℃ instead of the previous 100 ℃ by using sealed, thick-walled tubes to observe experimental phenomena further. It was found that another intramolecular process, i. e. B, R (Bonded State, Rotational State) conversion, exists in these complexes formed by polyaminepolycarboxylic ligands in addition to △,A conversion and nitrogen inversion. A quantitative treatment was proposed to estimate the relative populations of acetate groups in B and R states.展开更多
The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts a...The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.展开更多
This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type ...This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type microchannel from two inlets.The transfer function for the Y-type microchannel is given by solving the governing equation for the Taylor-Aris dispersion in the microchannel. The amplitude-frequency and phase-frequency relations are provided which show that a shallow Y-type microchannel acts as a low-pass filter. The transports of different dynamic biochemical signals are investigated. In comparison with a fully mixing microfluidic channel, the magnitudes of the dynamic signals at the outlets in a Y-type microchannel are much smaller than those in a fully mixing microchannel, which demonstrates that the amplitude attenuation in a Y-type microchannel is larger than that of a fully mixing microchannel due to the transverse molecular diffusion. In order to control the desired signal in a microchannel, the solution of the inverse problem for the channel is also presented.展开更多
On account of the traditional method in hybrid stability analysis being too rough, a new method of taking dual or single mode was put forward for 4 typical levers in the hybrid stability analysis respectively and tran...On account of the traditional method in hybrid stability analysis being too rough, a new method of taking dual or single mode was put forward for 4 typical levers in the hybrid stability analysis respectively and transited to the dynamic analysis smoothly. After verifying the superiority of the method through examples, the broad application prospect would be given in the end.展开更多
基金supported by the National Natural Science Foundation of China (Nos.51575289,51705270)the Key Research and Development Project of Shandong Province,China (No.2019GHY112068)the Natural Science Foundation of Shandong Province,China (No.ZR2019PEE028)。
文摘The effect of Gd content ranging from 6.5 wt.%to 8.5 wt.%on microstructure evolution and dynamic mechanical behavior of Mg−xGd−3Y−0.5Zr alloys was investigated by optical microscopy,X-ray diffraction,scanning electron microscopy and split Hopkinson pressure bar.The microstructure of as-cast Mg−xGd−3Y−0.5Zr alloys indicates that the addition of Gd can promote grain refinement in the casting.Due to the rapid cooling rate during solidification,a large amount of non-equilibrium eutectic phase Mg_(24)(Gd,Y)_(5) appears at the grain boundary of as-cast Mg−xGd−3Y−0.5Zr alloys.After solution treatment at 520℃ for 6 h,the Mg_(24)(Gd,Y)_(5) phase dissolves into the matrix,and the rare earth hydrides(REH)phase appears.The stress−strain curves validate that the solution-treated Mg−xGd−3Y−0.5Zr alloys with optimal Gd contents maintain excellent dynamic properties at different strain rates.It was concluded that the variation of Gd content and the agglomeration of residual REH particles and dynamically precipitated fine particles are key factors affecting dynamic mechanical properties of Mg−xGd−3Y−0.5Zr alloys.
基金Project supported by the Grant of the Korean Ministry of Education, Science and Technology (The Regional Core Research Program/Center for Healthcare Technology Development)
文摘This paper proposes an y2-y∞ learning law as a new learning method for dynamic neural networks with external disturbance. Based on linear matrix inequality （LMI） formulation, the y2-y∞ learning law is presented to not only guarantee asymptotical stability of dynamic neural networks but also reduce the effect of external disturbance to an y2-y∞ induced norm constraint. It is shown that the design of the y2-y∞ learning law for such neural networks can be achieved by solving LMIs, which can be easily facilitated by using some standard numerical packages. A numerical example is presented to demonstrate the validity of the proposed learning law.
基金Project supported by the Science Challenge Project of China(Grant No.TZ2016002)the National Natural Science Foundation of China(Grant No.50871057)
文摘A comparative study of cascades in nanostructured ferritic alloys and pure Fe is performed to reveal the influence of Y_2Ti_2O_7 nanocluster on cascades by molecular dynamics simulations. The cascades with energies of primary knock-on atom（PKA） ranging from 0.5 keV to 4.0 keV and PKA＇s distances to the interface from 0 to 50 are simulated. It turns out that the Y_2Ti_2O_7 nanocluster can absorb the kinetic energy of cascade atoms, prevent the cascade from extending and reduce the defect production significantly when the cascades overlap with the nanocluster. When the cascade affects seriously the nanocluster, the weak sub-cascade collisions are rebounded by the nanocluster and thus leave more interstitials in the matrix. On the contrary, when the cascade contacts weakly the nanocluster, the interface can pin the arrived interstitials and this leaves more vacancies in the matrix. Moreover, the results indicate that the Y_2Ti_2O_7 nanocluster keeps stable upon the displacement cascade damage.
文摘In this paper, samples of CaO-riched MgO-CaO added with Y2O3 were prepared and the growth rate of MgO grains were investigated, and the calculation of the grain growth active energy at different temperatures was done for the high performance anti-hydration CaO-riched MgO-CaO clinker. It is of significance for decreasing the synthetic temperature in industry production.
基金Supported by the National Natural Science Foundation of China
文摘The intramolecular process of Mg ( Ⅱ ) - , Sc ( Ⅲ ) - , Y ( Ⅲ ) - , In(Ⅲ)-and Pb ( Ⅱ )-trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA) complexes was studied by the method of proton dynamic NMR(DNMR). The top limit of. the experimental temperature range of deuterium oxide solutions was extended from 100℃ to 167 ℃ instead of the previous 100 ℃ by using sealed, thick-walled tubes to observe experimental phenomena further. It was found that another intramolecular process, i. e. B, R (Bonded State, Rotational State) conversion, exists in these complexes formed by polyaminepolycarboxylic ligands in addition to △,A conversion and nitrogen inversion. A quantitative treatment was proposed to estimate the relative populations of acetate groups in B and R states.
基金Project supported by the National Natural Science Foundation of China(Nos.11172060 and11672065)
文摘The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.
基金National Natural Science Foundation of Chinagrant number:11172060the Fundamental Research Funds for the Central Universities in China
文摘This paper presents an analysis of dispersion of dynamic biochemical signals in steady flow in a shallow Y-type microfluidic channel. A method is presented to control the flow widths of two steady flows in the Y-type microchannel from two inlets.The transfer function for the Y-type microchannel is given by solving the governing equation for the Taylor-Aris dispersion in the microchannel. The amplitude-frequency and phase-frequency relations are provided which show that a shallow Y-type microchannel acts as a low-pass filter. The transports of different dynamic biochemical signals are investigated. In comparison with a fully mixing microfluidic channel, the magnitudes of the dynamic signals at the outlets in a Y-type microchannel are much smaller than those in a fully mixing microchannel, which demonstrates that the amplitude attenuation in a Y-type microchannel is larger than that of a fully mixing microchannel due to the transverse molecular diffusion. In order to control the desired signal in a microchannel, the solution of the inverse problem for the channel is also presented.
文摘On account of the traditional method in hybrid stability analysis being too rough, a new method of taking dual or single mode was put forward for 4 typical levers in the hybrid stability analysis respectively and transited to the dynamic analysis smoothly. After verifying the superiority of the method through examples, the broad application prospect would be given in the end.
