The hybrid genetic algorithm is utilized to facilitate model parameter estimation.The tri-dimensional compression tests of soil are performed to supply experimental data for identifying nonlinear constitutive model of...The hybrid genetic algorithm is utilized to facilitate model parameter estimation.The tri-dimensional compression tests of soil are performed to supply experimental data for identifying nonlinear constitutive model of soil.In order to save computing time during parameter inversion,a new procedure to compute the calculated strains is presented by multi-linear simplification approach instead of finite element method(FEM).The real-coded hybrid genetic algorithm is developed by combining normal genetic algorithm with gradient-based optimization algorithm.The numerical and experimental results for conditioned soil are compared.The forecast strains based on identified nonlinear constitutive model of soil agree well with observed ones.The effectiveness and accuracy of proposed parameter estimation approach are validated.展开更多
Based on the hyperbolic mild-slope equations derived by Copeland (1985), a numerical model is established in unstag- gered grids. A composite 4 th-order Adam-Bashforth-Moulton (ABM) scheme is used to solve the model i...Based on the hyperbolic mild-slope equations derived by Copeland (1985), a numerical model is established in unstag- gered grids. A composite 4 th-order Adam-Bashforth-Moulton (ABM) scheme is used to solve the model in the time domain. Terms involving the first order spatial derivatives are differenced to O ( Δx )4accuracy utilizing a five-point formula. The nonlinear dispersion relationship proposed by Kirby and Dalrymple (1986) is used to consider the nonlinear effect. A numerical test is performed upon wave propagating over a typical shoal. The agreement between the numerical and the experimental results validates the present model. Biodistribution and applications are also summarized.展开更多
In order to improve the parasites experimental teaching quality, Digital Microscope System is used to replace the ordinary optical microscope in the teaching of eggs, imagoes, and tissue slices. The new model of exper...In order to improve the parasites experimental teaching quality, Digital Microscope System is used to replace the ordinary optical microscope in the teaching of eggs, imagoes, and tissue slices. The new model of experimental teaching, integrating modem information technology into the parasite experimental teaching, gives full play to the students＇ learning enthusiasm, initiative and creativity and improves the quality of experimental teaching. And at the same time, it provides a basis for the microbiological and pathological experimental teaching reform.展开更多
The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls ＆pla...The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls ＆plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional （RPBE） approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on： coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses （arabinose, xylose, glucose, galactose, and mannose） were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD （Vibrations Basis Database） for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.展开更多
基金Project(2007CB714006) supported by the National Basic Research Program of China Project(90815023) supported by the National Natural Science Foundation of China
文摘The hybrid genetic algorithm is utilized to facilitate model parameter estimation.The tri-dimensional compression tests of soil are performed to supply experimental data for identifying nonlinear constitutive model of soil.In order to save computing time during parameter inversion,a new procedure to compute the calculated strains is presented by multi-linear simplification approach instead of finite element method(FEM).The real-coded hybrid genetic algorithm is developed by combining normal genetic algorithm with gradient-based optimization algorithm.The numerical and experimental results for conditioned soil are compared.The forecast strains based on identified nonlinear constitutive model of soil agree well with observed ones.The effectiveness and accuracy of proposed parameter estimation approach are validated.
基金This work is financially supported by the National Natural Science Foundation of China （50409015）.
文摘Based on the hyperbolic mild-slope equations derived by Copeland (1985), a numerical model is established in unstag- gered grids. A composite 4 th-order Adam-Bashforth-Moulton (ABM) scheme is used to solve the model in the time domain. Terms involving the first order spatial derivatives are differenced to O ( Δx )4accuracy utilizing a five-point formula. The nonlinear dispersion relationship proposed by Kirby and Dalrymple (1986) is used to consider the nonlinear effect. A numerical test is performed upon wave propagating over a typical shoal. The agreement between the numerical and the experimental results validates the present model. Biodistribution and applications are also summarized.
文摘In order to improve the parasites experimental teaching quality, Digital Microscope System is used to replace the ordinary optical microscope in the teaching of eggs, imagoes, and tissue slices. The new model of experimental teaching, integrating modem information technology into the parasite experimental teaching, gives full play to the students＇ learning enthusiasm, initiative and creativity and improves the quality of experimental teaching. And at the same time, it provides a basis for the microbiological and pathological experimental teaching reform.
文摘The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls ＆plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional （RPBE） approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on： coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses （arabinose, xylose, glucose, galactose, and mannose） were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD （Vibrations Basis Database） for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.
