Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season a...Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season are computed to drive the 3D model of Fe and Mn in which the processes of advection, diffusion, redox, sorption, desorption, deposition, and re suspension are included. The model has been calibrated by matching observed fluid, suspended solids, and total concentrations of Fe and Mn in the water column and in the sediment, successively. The model simulated both horizontal and vertical gradients of Fe and Mn in Arha Reservoir. It was found that Fe and especially Mn stratify in accordance with the stratification of DO during summer. The redox cycles across the water sediment interface has a principal role in the rise of Fe and Mn concentrations in the overlying water. It was also found that Fe and Mn loadings from the tributaries have a carryover effect on the water quality through a secondary contamination in the reservoir.展开更多
The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and ca...The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis(DED) was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1(Mad1) using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.展开更多
The dynamic updating of the model included: the change of space border,addi- tion and reduction of spatial component (disappearing,dividing and merging),the change of the topological relationship and synchronous dynam...The dynamic updating of the model included: the change of space border,addi- tion and reduction of spatial component (disappearing,dividing and merging),the change of the topological relationship and synchronous dynamic updating of database.Firstly, arming at the deficiency of OO-Solid model in the aspect of dynamic updating,modeling primitives of OO-Solid model were modified.And then the algorithms of dynamic updating of 3D geological model with the node data,line data or surface data change were dis- cussed.The core algorithms was done by establishing space index,following the way of facing the object from bottom to top,namely the dynamic updating from the node to arc, and then to polygon,then to the face of the component and finally to the geological object. The research has important theoretical and practical values in the field of three dimen- sional geological modeling and is significant in the field of mineral resources.展开更多
Taking the transport of total phosphor pollutants in the Beijing Miyun reservoir for example,we have obtained three dimensional distributing regularity of total phosphor pollutants by the calculation of the linear int...Taking the transport of total phosphor pollutants in the Beijing Miyun reservoir for example,we have obtained three dimensional distributing regularity of total phosphor pollutants by the calculation of the linear interpolation value of each point between horizontal layers. The credibility analysis in allusion to this method was carried out and the programming scheme for realizing this method was set forth.展开更多
Based on the necessity of three dimensional modeling with computer in teaching reform, this paper is the summarization of reform practice of teaching engineering drawing in our institute. The teaching reform begins wi...Based on the necessity of three dimensional modeling with computer in teaching reform, this paper is the summarization of reform practice of teaching engineering drawing in our institute. The teaching reform begins with three dimensional modeling that used computer instead of board. On the basis of target of teaching reform, set of teaching content, arrangement of class hour and teaching method, the research of teaching practice have been done, and very good effects in teaching of engineering drawing have been achieved.展开更多
This research provides an exploration of a biomimetic approach in the process of designing a candelabra model using linear shaped leaves of a Bell flower.The design process described in this research contains two step...This research provides an exploration of a biomimetic approach in the process of designing a candelabra model using linear shaped leaves of a Bell flower.The design process described in this research contains two steps:biological and geometrical.In the first biological step,a proper model for the creation of an urban element was found from nature in a Bell flower(Campanula persicifolia L.).The upper leaves of the selected plant,which are small with a linear spear and sharpening at the top,were chosen for the modeling process.The second step included applying two geometrical methods,i.e.,Voronoi diagrams and Delaunay triangulation.A geometrical leaf form of the selected plant species and the modeling process were obtained using aparametric modeling software,Blender.Using different Blender plug-ins and modifiers,Delaunay triangulation and Voronoi diagram were implemented by marking the starting points on the leaf form in the image data source,adjusting the Delaunay triangulation parameters,and creating Voronoi diagrams in which the Voronoi points were located at the shortest distance from the edges of the Voronoi polygon.Consequently,a three dimensional model of a candelabra was developed through this study.展开更多
The flow behavior of three-dimensional(3D)dendrite growth with random preferred angle under natural convection was studied by using the Lattice Boltzmann-Cellular Automata(LB-CA)method with dynamic and static grids.In...The flow behavior of three-dimensional(3D)dendrite growth with random preferred angle under natural convection was studied by using the Lattice Boltzmann-Cellular Automata(LB-CA)method with dynamic and static grids.In this model,the temperature field,flow field and solute field calculated by Lattice Boltzmann method(LBM)and dendrite growth calculated by CA method were carried out in static and dynamic grids respectively,and the coupling between LBM and CA was performed by interpolation of calculation parameters between dynamic and static grids.Results show that the asymmetry of solid phase distribution makes the streamline distribution more complex.At the initial stage of multiple dendrites growth,the fluid flow is relatively free.When dendrites grow close to each other,the fluid flow is blocked and can only flow along the gap between dendrites.During the wall equiaxed-columnar-central equiaxed crystals transformation(ECET)process,dense eddy current is formed at the wall equiaxed crystals at first.Then,when the wall equiaxed crystals gradually develop into columnar crystals,the eddy current moves with the solid-liquid interface.When the central equiaxed crystals are formed,the eddy current at the front of the columnar crystals gradually disappears.New eddies appear as the central equiaxed crystal grows.展开更多
In the previous study, we suggested the concept of new TQM based on the consideration of basic concept of Quality Control. Also, in the previous study, we suggested the target domains and entities of product and proce...In the previous study, we suggested the concept of new TQM based on the consideration of basic concept of Quality Control. Also, in the previous study, we suggested the target domains and entities of product and process based on the TQM Matrix and view point of Three Dimensional Unification Value Models for managing quality of organization systems. Furthermore, in the previous study, we suggest the Common Management Process of organizations. Based on the above suggestion, in this paper, we would like to propose the Common Management Process Model of Total Quality Management based on the consideration of situation analysis and more precise definition of TQM Matrix and Three Dimensional Unification Value Model of “Product and Process”. Improvement of quality and efficiency of organization management can be expected by the integration of conventional different management such as quality assurance, quality improvement, risk management, investment individually from the view point of common management process.展开更多
To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation(NBHE) was developed...To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation(NBHE) was developed.To support the NBHE method, a numerical bay health index(NBHI) system was constructed, which assess the natural and socio-economic effects on the entire bay. Five index groups are combined to formulate the NBHI,including geometry, hydrodynamics and sediment dynamics, bio-ecology, water quality and socio-economy.Each group has different number of indices selected and weighted using AHP method according to their importance. Data were mainly synthesized from a variety of numerical models together with monitoring programs, which provide superior to other approaches in discriminating data integrity and predicting data in future. The NBHE method using NBHI system was applied in the Yueqing Bay during spring tide in April 2007.According to the NBHE results, Sta. A, at the surface level of the estuarine mouth, has a healthy geometry condition, sub-healthy hydrodynamic and sediment dynamic condition, and unhealthy water quality and bioecology conditions. The integrated healthy score at Sta. A indicates its sub-healthy condition.展开更多
A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolutio...A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.展开更多
An improved model for numerically predicting nonlinear wave forces exerted on an offshore structure is pro- posed.In a previous work[9],the authors presented a model for the same purpose with an open boundary condi- t...An improved model for numerically predicting nonlinear wave forces exerted on an offshore structure is pro- posed.In a previous work[9],the authors presented a model for the same purpose with an open boundary condi- tion imposed,where the wave celerity has been defined constant.Generally,the value of wave celerity is time-de- pendent and varying with spatial location.With the present model the wave celerity is evaluated by an upwind dif- ference scheme,which enables the method to be extended to conditions of variable finite water depth,where the value of wave celerity varies with time as the wave approaches the offshore structure.The finite difference method incorporated with the time-stepping technique in time domain developed here makes the numerical evolution effec- tive and stable.Computational examples on interactions between a surface-piercing vertical cylinder and a solitary wave or a cnoidal wave train demonstrates the validity of this program.展开更多
A three dimensional numerical model based on the Reynolds equations is presented that can be used to predict the surface water flow in open channels.The model uses a computational mesh that conforms to the free water ...A three dimensional numerical model based on the Reynolds equations is presented that can be used to predict the surface water flow in open channels.The model uses a computational mesh that conforms to the free water sur- face and the bottom of the channel so that the accuracy of boundary condition application,code complexity,and e- conomy could be enhanced.The k-ε turbulence model is used to estimate the eddy viscosity coefficient.Instead of using the“rigid-lid”approximation a 2-D equation derived from integrating the continuity equation over the total depth is adopted to determine the elevation of the free water surface.A new algorithm is presented based on the conventional SIMPLE procedure.The block correction technique is employed to enhance rate of convergence. The model presented is applied to a bottom discharge into a rectangular straight channel for three dimensional phenomena to obtain the free water surface configuration,velocities and pressure.The computed results are in good agreement with the previous experimental values.展开更多
采用三维网格和VOF(Volume of Fluids)多相流模型,对非轴对称、X型舵的航行体水下点火这一非稳态过程进行了三维流场数值模拟,捕捉了燃气泡的形成、发展及断裂过程,得到了航行体水下点火初期的流场变化和阻力变化,并进行了相关因素探讨...采用三维网格和VOF(Volume of Fluids)多相流模型,对非轴对称、X型舵的航行体水下点火这一非稳态过程进行了三维流场数值模拟,捕捉了燃气泡的形成、发展及断裂过程,得到了航行体水下点火初期的流场变化和阻力变化,并进行了相关因素探讨和结果对比分析。研究表明,燃气泡的发展变化过程对航行体流场和阻力产生影响。该研究可为航行体水下点火设计及试验提供参考。展开更多
A 53-year-old woman underwent a 2-stage right hepatectomy for bilobar metastasis of an ileal neuroendocrine carcinoma. Preoperative three-dimensional computed tomography reconstruction helped to diagnose an intrahepat...A 53-year-old woman underwent a 2-stage right hepatectomy for bilobar metastasis of an ileal neuroendocrine carcinoma. Preoperative three-dimensional computed tomography reconstruction helped to diagnose an intrahepatic venovenous shunts from the right and middle hepatic veins to the left hepatic vein, which could cause a intraoperative bleeding. Hemostasis was performed by means of precoagulation with microwaveassisted coagulation.展开更多
During the last years, the topic of accessibility of cultural heritage is getting so important all around the Europe. For disseminating a research data and information, it is important to use a simple language and an...During the last years, the topic of accessibility of cultural heritage is getting so important all around the Europe. For disseminating a research data and information, it is important to use a simple language and an effective communication. The data research produced by specialists has three formal levels: The third one of communication system aims to break barriers to reach a wide audience. The present study wants to demonstrate the role of images in the process of deductive inference by three dimensional (3D) reconstruction of cultural heritage. The case study of Federico da Montefeltro office shows how inter-disciplinary works and technological resource can help society to understand history and meaning of heritage.展开更多
Traditional method to prevent stored grain from deterioration is to control grain temperature.A three dimensional(3-D)numerical model was established to study the temperature variation in outdoor squat silo and large ...Traditional method to prevent stored grain from deterioration is to control grain temperature.A three dimensional(3-D)numerical model was established to study the temperature variation in outdoor squat silo and large size horizontal warehouse at quasi-steady-state.In this research,porous media model and solar radiation model were adopted.Numerical and experimental results showed that grain temperature was influenced by temperature of wall,height of grain and the distance between grain and the wall.Temperature changes dramatically at the top layer of grain heap due to solar radiation and heat convection at air layer.Temperature of grain close to wall increased with the increasing of ambient temperature.The model established in this research is suitable for predicting grain temperature in outdoor squat silo and large size horizontal warehouse.展开更多
As part of a major effort to undersand and quantify the cnvironmental conditions in Lake Yanaka, the circulation patterns in Lake Yanaka were analyzed through the application of a three dimensional hydrodynamic model...As part of a major effort to undersand and quantify the cnvironmental conditions in Lake Yanaka, the circulation patterns in Lake Yanaka were analyzed through the application of a three dimensional hydrodynamic model. The model was validated with field observation, and then used to study the response of the lake to different forcing. The information on flow structures obtained in the present study is useful for further study of water quality in the lake.展开更多
文摘Coupling with a three dimensional (3D) hydrodynamic model and a suspended solids model, a 3D model for the transport of Fe and Mn in Arha Reservoir, China, was developed. The 3D velocity fields for the flood season are computed to drive the 3D model of Fe and Mn in which the processes of advection, diffusion, redox, sorption, desorption, deposition, and re suspension are included. The model has been calibrated by matching observed fluid, suspended solids, and total concentrations of Fe and Mn in the water column and in the sediment, successively. The model simulated both horizontal and vertical gradients of Fe and Mn in Arha Reservoir. It was found that Fe and especially Mn stratify in accordance with the stratification of DO during summer. The redox cycles across the water sediment interface has a principal role in the rise of Fe and Mn concentrations in the overlying water. It was also found that Fe and Mn loadings from the tributaries have a carryover effect on the water quality through a secondary contamination in the reservoir.
基金supported by the Middlesex University,particularly in the award of a Postgraduate Research Studentship that provided the necessary financial support for this research
文摘The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis(DED) was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1(Mad1) using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.
基金the National Natural Science Foundation of China(40572165)
文摘The dynamic updating of the model included: the change of space border,addi- tion and reduction of spatial component (disappearing,dividing and merging),the change of the topological relationship and synchronous dynamic updating of database.Firstly, arming at the deficiency of OO-Solid model in the aspect of dynamic updating,modeling primitives of OO-Solid model were modified.And then the algorithms of dynamic updating of 3D geological model with the node data,line data or surface data change were dis- cussed.The core algorithms was done by establishing space index,following the way of facing the object from bottom to top,namely the dynamic updating from the node to arc, and then to polygon,then to the face of the component and finally to the geological object. The research has important theoretical and practical values in the field of three dimen- sional geological modeling and is significant in the field of mineral resources.
文摘Taking the transport of total phosphor pollutants in the Beijing Miyun reservoir for example,we have obtained three dimensional distributing regularity of total phosphor pollutants by the calculation of the linear interpolation value of each point between horizontal layers. The credibility analysis in allusion to this method was carried out and the programming scheme for realizing this method was set forth.
基金Supported by Beijing City Institution of Higher Learning Talent Education Program Project Foundation (PHR200906213PHR201007234)
文摘Based on the necessity of three dimensional modeling with computer in teaching reform, this paper is the summarization of reform practice of teaching engineering drawing in our institute. The teaching reform begins with three dimensional modeling that used computer instead of board. On the basis of target of teaching reform, set of teaching content, arrangement of class hour and teaching method, the research of teaching practice have been done, and very good effects in teaching of engineering drawing have been achieved.
基金The Ministry of Education,Science and Technological Development of the Republic of Serbia,No.TP 36008(451–02-68/2020/14/2000169).
文摘This research provides an exploration of a biomimetic approach in the process of designing a candelabra model using linear shaped leaves of a Bell flower.The design process described in this research contains two steps:biological and geometrical.In the first biological step,a proper model for the creation of an urban element was found from nature in a Bell flower(Campanula persicifolia L.).The upper leaves of the selected plant,which are small with a linear spear and sharpening at the top,were chosen for the modeling process.The second step included applying two geometrical methods,i.e.,Voronoi diagrams and Delaunay triangulation.A geometrical leaf form of the selected plant species and the modeling process were obtained using aparametric modeling software,Blender.Using different Blender plug-ins and modifiers,Delaunay triangulation and Voronoi diagram were implemented by marking the starting points on the leaf form in the image data source,adjusting the Delaunay triangulation parameters,and creating Voronoi diagrams in which the Voronoi points were located at the shortest distance from the edges of the Voronoi polygon.Consequently,a three dimensional model of a candelabra was developed through this study.
基金financially supported by the National Natural Science Foundation of China (Nos. 51475138 and 51975182)
文摘The flow behavior of three-dimensional(3D)dendrite growth with random preferred angle under natural convection was studied by using the Lattice Boltzmann-Cellular Automata(LB-CA)method with dynamic and static grids.In this model,the temperature field,flow field and solute field calculated by Lattice Boltzmann method(LBM)and dendrite growth calculated by CA method were carried out in static and dynamic grids respectively,and the coupling between LBM and CA was performed by interpolation of calculation parameters between dynamic and static grids.Results show that the asymmetry of solid phase distribution makes the streamline distribution more complex.At the initial stage of multiple dendrites growth,the fluid flow is relatively free.When dendrites grow close to each other,the fluid flow is blocked and can only flow along the gap between dendrites.During the wall equiaxed-columnar-central equiaxed crystals transformation(ECET)process,dense eddy current is formed at the wall equiaxed crystals at first.Then,when the wall equiaxed crystals gradually develop into columnar crystals,the eddy current moves with the solid-liquid interface.When the central equiaxed crystals are formed,the eddy current at the front of the columnar crystals gradually disappears.New eddies appear as the central equiaxed crystal grows.
文摘In the previous study, we suggested the concept of new TQM based on the consideration of basic concept of Quality Control. Also, in the previous study, we suggested the target domains and entities of product and process based on the TQM Matrix and view point of Three Dimensional Unification Value Models for managing quality of organization systems. Furthermore, in the previous study, we suggest the Common Management Process of organizations. Based on the above suggestion, in this paper, we would like to propose the Common Management Process Model of Total Quality Management based on the consideration of situation analysis and more precise definition of TQM Matrix and Three Dimensional Unification Value Model of “Product and Process”. Improvement of quality and efficiency of organization management can be expected by the integration of conventional different management such as quality assurance, quality improvement, risk management, investment individually from the view point of common management process.
基金The Key National Project under contract No.009zx07424-001Doctoral Fund of Ministry of Education of China under contract No.2012101110108+2 种基金MEL Visiting Fellowship Programthe Fundamental Research Funds for the Central UniversitiesZhejiang Provincial Natural Science Foundation of China under contract No.LQ16D060002
文摘To better evaluate the three-dimensional bay health and predict the dynamic bay health conditions, a concept of numerical bay health was introduced and a method of numerical bay health evaluation(NBHE) was developed.To support the NBHE method, a numerical bay health index(NBHI) system was constructed, which assess the natural and socio-economic effects on the entire bay. Five index groups are combined to formulate the NBHI,including geometry, hydrodynamics and sediment dynamics, bio-ecology, water quality and socio-economy.Each group has different number of indices selected and weighted using AHP method according to their importance. Data were mainly synthesized from a variety of numerical models together with monitoring programs, which provide superior to other approaches in discriminating data integrity and predicting data in future. The NBHE method using NBHI system was applied in the Yueqing Bay during spring tide in April 2007.According to the NBHE results, Sta. A, at the surface level of the estuarine mouth, has a healthy geometry condition, sub-healthy hydrodynamic and sediment dynamic condition, and unhealthy water quality and bioecology conditions. The integrated healthy score at Sta. A indicates its sub-healthy condition.
基金Supported by the National Basic Research Program of China(Grant No 2006CB403302)the National Natural Science Foundation of China(Grant No 50839001)
文摘A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.
基金China National Sicence Foundation with Grant No.91870003
文摘An improved model for numerically predicting nonlinear wave forces exerted on an offshore structure is pro- posed.In a previous work[9],the authors presented a model for the same purpose with an open boundary condi- tion imposed,where the wave celerity has been defined constant.Generally,the value of wave celerity is time-de- pendent and varying with spatial location.With the present model the wave celerity is evaluated by an upwind dif- ference scheme,which enables the method to be extended to conditions of variable finite water depth,where the value of wave celerity varies with time as the wave approaches the offshore structure.The finite difference method incorporated with the time-stepping technique in time domain developed here makes the numerical evolution effec- tive and stable.Computational examples on interactions between a surface-piercing vertical cylinder and a solitary wave or a cnoidal wave train demonstrates the validity of this program.
基金This work is supported by Chinese National Natural Science Foundation.
文摘A three dimensional numerical model based on the Reynolds equations is presented that can be used to predict the surface water flow in open channels.The model uses a computational mesh that conforms to the free water sur- face and the bottom of the channel so that the accuracy of boundary condition application,code complexity,and e- conomy could be enhanced.The k-ε turbulence model is used to estimate the eddy viscosity coefficient.Instead of using the“rigid-lid”approximation a 2-D equation derived from integrating the continuity equation over the total depth is adopted to determine the elevation of the free water surface.A new algorithm is presented based on the conventional SIMPLE procedure.The block correction technique is employed to enhance rate of convergence. The model presented is applied to a bottom discharge into a rectangular straight channel for three dimensional phenomena to obtain the free water surface configuration,velocities and pressure.The computed results are in good agreement with the previous experimental values.
文摘采用三维网格和VOF(Volume of Fluids)多相流模型,对非轴对称、X型舵的航行体水下点火这一非稳态过程进行了三维流场数值模拟,捕捉了燃气泡的形成、发展及断裂过程,得到了航行体水下点火初期的流场变化和阻力变化,并进行了相关因素探讨和结果对比分析。研究表明,燃气泡的发展变化过程对航行体流场和阻力产生影响。该研究可为航行体水下点火设计及试验提供参考。
基金Institut Hospitalo-Universitaire de Strasbourg(IHU MixSurg),Strasbourg,France
文摘A 53-year-old woman underwent a 2-stage right hepatectomy for bilobar metastasis of an ileal neuroendocrine carcinoma. Preoperative three-dimensional computed tomography reconstruction helped to diagnose an intrahepatic venovenous shunts from the right and middle hepatic veins to the left hepatic vein, which could cause a intraoperative bleeding. Hemostasis was performed by means of precoagulation with microwaveassisted coagulation.
文摘During the last years, the topic of accessibility of cultural heritage is getting so important all around the Europe. For disseminating a research data and information, it is important to use a simple language and an effective communication. The data research produced by specialists has three formal levels: The third one of communication system aims to break barriers to reach a wide audience. The present study wants to demonstrate the role of images in the process of deductive inference by three dimensional (3D) reconstruction of cultural heritage. The case study of Federico da Montefeltro office shows how inter-disciplinary works and technological resource can help society to understand history and meaning of heritage.
基金National Natural Science Foundation of China(31271972)University Science and Technology Innovation Team Support Plan of Henan Province,China in 2016(16IRTSTHN009).
文摘Traditional method to prevent stored grain from deterioration is to control grain temperature.A three dimensional(3-D)numerical model was established to study the temperature variation in outdoor squat silo and large size horizontal warehouse at quasi-steady-state.In this research,porous media model and solar radiation model were adopted.Numerical and experimental results showed that grain temperature was influenced by temperature of wall,height of grain and the distance between grain and the wall.Temperature changes dramatically at the top layer of grain heap due to solar radiation and heat convection at air layer.Temperature of grain close to wall increased with the increasing of ambient temperature.The model established in this research is suitable for predicting grain temperature in outdoor squat silo and large size horizontal warehouse.
文摘As part of a major effort to undersand and quantify the cnvironmental conditions in Lake Yanaka, the circulation patterns in Lake Yanaka were analyzed through the application of a three dimensional hydrodynamic model. The model was validated with field observation, and then used to study the response of the lake to different forcing. The information on flow structures obtained in the present study is useful for further study of water quality in the lake.