By using the spectrum expanding theory of random processes and Hudson's crack model,we developed a random medium model for rocks with spatial random distributed number density of cracks. This model could connect t...By using the spectrum expanding theory of random processes and Hudson's crack model,we developed a random medium model for rocks with spatial random distributed number density of cracks. This model could connect the micro-parameters of the cracks with the macro- mechanical properties, and can be effectively applied to model the real inhomogeneous medium. Numerical example indicates that the random distribution characters could be different for different elastic constants under the same random distribution of number density of cracks. By changing the value of the autocorrelation length pair, it is possible to model the difference of the distribution in the two coordinate directions. Numerical modeling results for seismic wave propagating in rocks with random distributed fractures using a staggered high-order finite-difference (SHOFD) are also presented.展开更多
Liquid distributor is a very import intemal for distillation columns. Pre-distributor is usually set on the top of distributor for initial distribution. Fluid flow in pre-distributor is a complex system of variable ma...Liquid distributor is a very import intemal for distillation columns. Pre-distributor is usually set on the top of distributor for initial distribution. Fluid flow in pre-distributor is a complex system of variable mass flow with many orifices and sub-branches. Consequently, the two phase modeling of pre-distributors was carried out andthe homogeneous model with free surface model was applied. The numerical method was validated by comparing with experimental data. Using the simulated results for different pre-distributors, the impacts of inflow rate, location and orientation uoon the outflow distribution were investigated. Furthermore, influences of the outflow distribution for pre-distributor on liquid uniformity in trough were also analyzed, The conclusions can De aaoptea for me structural design of liquid distributor and pre-distributor of large scale.展开更多
3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downs...3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downstream applications, simplified models in various levels of detail (LODs) are frequently more desirable than the full details of the parts. In particular, the need for feature-based multiresolution representation of a solid model representing an object at multiple LODs in the feature unit is increasing for engineering tasks. One challenge is to generate valid models at various LODs after an arbitrary rearrangement of features using a certain LOD criterion, because composite Boolean operations consisting of union and subtraction are not commutative. The other challenges are to devise proper topological framework for multiresolution representation, to suggest more reasonable LOD criteria, and to extend applications. This paper surveys the recent research on these issues.展开更多
Arthritis, most notably rheumatoid arthritis, can destroy the surfaces of the bones; the ideal solution for this is T JR （total joint replacement）, which would restore joint functionality, maintain correct aesthetic...Arthritis, most notably rheumatoid arthritis, can destroy the surfaces of the bones; the ideal solution for this is T JR （total joint replacement）, which would restore joint functionality, maintain correct aesthetics and eradicate pain for the patient. Current metacarpophalangeal TJR do not provide the normal biomechanical range of motion and functionality. The proposed design attempts to correct this through the use of design geometry and functional anatomy. Numerical analysis is used in conjunction with computational solid modeling to compare a one-piece silicone implant with the proposed T JR. Peak stresses during flexion for the proposed design did not exceed 1.2 MPa, where as soft implants approach 100 MPa to 1,000 MPa for peak stress values. The proposed design, due to high stress tolerances with low deformation, along with functionality and biomechanics, seems to be an appropriate replacement for one-piece silicone implant.展开更多
The purpose of the work is to identify the acoustic emission （AE） signal in the melt and from the interphase during the crystal growth and to establish the connection between issue parameters： the number of signal ...The purpose of the work is to identify the acoustic emission （AE） signal in the melt and from the interphase during the crystal growth and to establish the connection between issue parameters： the number of signal events of frequency and the signal power with the growth conditions of temperature gradient and crystallization rate. Experiments on single crystal growth were carried out using hardware and software system which allows to perform spectral Fourier analysis of AE signals and to simultaneously remove the cooling curve for the entire period of crystallization. On the basis of spectral analysis of AE signals, a theoretical model of clusters in the aluminum melt was designed. The experimental results indicate an uneven abrupt advancement of the interface according to the configuration of each individual cluster.展开更多
In this paper, we investigate the electron transfer(ET) in donor-acceptor model. The Langevin equation with random forces is used. The oscillations of the primary states observed in experimental data have been shown w...In this paper, we investigate the electron transfer(ET) in donor-acceptor model. The Langevin equation with random forces is used. The oscillations of the primary states observed in experimental data have been shown with this approach. And other features on the dependence of the rate of ET on temperature, free energy, and reorganization energy have also been clearly shown.展开更多
文摘By using the spectrum expanding theory of random processes and Hudson's crack model,we developed a random medium model for rocks with spatial random distributed number density of cracks. This model could connect the micro-parameters of the cracks with the macro- mechanical properties, and can be effectively applied to model the real inhomogeneous medium. Numerical example indicates that the random distribution characters could be different for different elastic constants under the same random distribution of number density of cracks. By changing the value of the autocorrelation length pair, it is possible to model the difference of the distribution in the two coordinate directions. Numerical modeling results for seismic wave propagating in rocks with random distributed fractures using a staggered high-order finite-difference (SHOFD) are also presented.
基金Supported by the National Key Basic Research and Development Program of China (2009CB219905, 2009CB219907)the Program for Changjiang Scholars and Innovative Research Teams in Universities (IRT0936)
文摘Liquid distributor is a very import intemal for distillation columns. Pre-distributor is usually set on the top of distributor for initial distribution. Fluid flow in pre-distributor is a complex system of variable mass flow with many orifices and sub-branches. Consequently, the two phase modeling of pre-distributors was carried out andthe homogeneous model with free surface model was applied. The numerical method was validated by comparing with experimental data. Using the simulated results for different pre-distributors, the impacts of inflow rate, location and orientation uoon the outflow distribution were investigated. Furthermore, influences of the outflow distribution for pre-distributor on liquid uniformity in trough were also analyzed, The conclusions can De aaoptea for me structural design of liquid distributor and pre-distributor of large scale.
基金Project supported by the Ministry of Education and Human Re-sources Development (MOE), the Ministry of Commerce, Industry and Energy (MOCIE) and the Ministry of Labor (MOLAB) through the Fostering Project of the Lab of Excellency, Korea
文摘3D computer-aided design (CAD) systems based on feature-based solid modelling technique have been widely spread and used for product design. However, when part models associated with features are used in various downstream applications, simplified models in various levels of detail (LODs) are frequently more desirable than the full details of the parts. In particular, the need for feature-based multiresolution representation of a solid model representing an object at multiple LODs in the feature unit is increasing for engineering tasks. One challenge is to generate valid models at various LODs after an arbitrary rearrangement of features using a certain LOD criterion, because composite Boolean operations consisting of union and subtraction are not commutative. The other challenges are to devise proper topological framework for multiresolution representation, to suggest more reasonable LOD criteria, and to extend applications. This paper surveys the recent research on these issues.
文摘Arthritis, most notably rheumatoid arthritis, can destroy the surfaces of the bones; the ideal solution for this is T JR （total joint replacement）, which would restore joint functionality, maintain correct aesthetics and eradicate pain for the patient. Current metacarpophalangeal TJR do not provide the normal biomechanical range of motion and functionality. The proposed design attempts to correct this through the use of design geometry and functional anatomy. Numerical analysis is used in conjunction with computational solid modeling to compare a one-piece silicone implant with the proposed T JR. Peak stresses during flexion for the proposed design did not exceed 1.2 MPa, where as soft implants approach 100 MPa to 1,000 MPa for peak stress values. The proposed design, due to high stress tolerances with low deformation, along with functionality and biomechanics, seems to be an appropriate replacement for one-piece silicone implant.
文摘The purpose of the work is to identify the acoustic emission （AE） signal in the melt and from the interphase during the crystal growth and to establish the connection between issue parameters： the number of signal events of frequency and the signal power with the growth conditions of temperature gradient and crystallization rate. Experiments on single crystal growth were carried out using hardware and software system which allows to perform spectral Fourier analysis of AE signals and to simultaneously remove the cooling curve for the entire period of crystallization. On the basis of spectral analysis of AE signals, a theoretical model of clusters in the aluminum melt was designed. The experimental results indicate an uneven abrupt advancement of the interface according to the configuration of each individual cluster.
基金Supported by the National Natural Science Foundation of China under Grant No.61078065the Zhejiang Provincial Natural Science Foundation of China under Grant No.LY13A040006the K.C.Wong Magna Foundation in Ningbo University
文摘In this paper, we investigate the electron transfer(ET) in donor-acceptor model. The Langevin equation with random forces is used. The oscillations of the primary states observed in experimental data have been shown with this approach. And other features on the dependence of the rate of ET on temperature, free energy, and reorganization energy have also been clearly shown.
