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Science Letters:Dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modelling language (VRML) 被引量:3
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作者 禹正杨 郑树森 +2 位作者 陈雷霆 何晓乾 王建军 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第7期611-616,共6页
This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize t... This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging. 展开更多
关键词 Virtual Reality modelling Language (VRML) Direct texture mapping three-dimensional reconstruction dynamic concision
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Three-Dimensional Nonlinear Dynamic Model and Macro Control of Real Estate
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作者 Dan Ma Shengwu Zhou Haojin Lv 《Intelligent Information Management》 2010年第5期325-328,共4页
In this paper, according to economics of real estate and macro-control theory, combine with the characteristics of the real estate market, macro-control of the real estate market is studied. After giving the dynamic m... In this paper, according to economics of real estate and macro-control theory, combine with the characteristics of the real estate market, macro-control of the real estate market is studied. After giving the dynamic model of three-dimensional nonlinear differential equations based on the total number of houses on the real estate business, the government’s averages housing investment funds and the standard price, systematically established the stability conditions of equilibrium point for this model. What’s more, through the use of extreme value analysis model, government funds have been invested in real estate business building devotion principles and the construction base of the real estate businessmen has also been estimated successfully. This provides the corresponding theoretical basis for government macro control policy-making. 展开更多
关键词 REAL EsTATE MACRO Control three-dimensional dynamic model EXTREME Value Analysis
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Predicting the Dynamic Behavior of Asphalt Concrete Using Three-dimensional Discrete Element Method 被引量:4
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作者 陈俊 PAN Tongyan +2 位作者 CHEN Jingya HUANG Xiaoming LU Yang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第2期382-388,共7页
A user-defined three-dimensional (3D) discrete element model was presented to predict the dynamic modulus and phase angle of asphalt concrete (AC). The 3D discrete element method (DEM) model of AC was constructe... A user-defined three-dimensional (3D) discrete element model was presented to predict the dynamic modulus and phase angle of asphalt concrete (AC). The 3D discrete element method (DEM) model of AC was constructed employing a user-defined computer program developed using the "Fish" language in PFC3D. Important microstructural features of AC were modeled, including aggregate gradation, air voids and mastic. The irregular shape of aggregate particle was modeled using a clump of spheres. The developed model was validated through comparing with experimental measurements and then used to simulate the cyclic uniaxial compression test, based on which the dynamic modulus and phase angle were calculated from the output stress- strain relationship. The effects of air void content, aggregate stiffness and volumetric fraction on AC modulus were further investigated. The experimental results show that the 3D DEM model is able to accurately predict both dynamic modulus and phase angle of AC across a range of temperature and loading frequencies. The user- defined 3D model also demonstrated significant improvement over the general existing two-dimensional models. 展开更多
关键词 asphalt concrete dynamic modulus MICROMECHANICs discrete element method three-dimensional model uniaxial compression test
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Bus frequency optimization in a large-scale multi-modal transportation system:integrating 3D-MFD and dynamic traffic assignment
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作者 Kai Yuan Dandan Cui Jiancheng Long 《Digital Transportation and Safety》 2023年第4期241-252,共12页
A properly designed public transport system is expected to improve traffic efficiency.A high-frequency bus service would decrease the waiting time for passengers,but the interaction between buses and cars might result... A properly designed public transport system is expected to improve traffic efficiency.A high-frequency bus service would decrease the waiting time for passengers,but the interaction between buses and cars might result in more serious congestion.On the other hand,a low-frequency bus service would increase the waiting time for passengers and would not reduce the use of private cars.It is important to strike a balance between high and low frequencies in order to minimize the total delays for all road users.It is critical to formulate the impacts of bus frequency on congestion dynamics and mode choices.However,as far as the authors know,most proposed bus frequency optimization formulations are based on static demand and the Bureau of Public Roads function,and do not properly consider the congestion dynamics and their impacts on mode choices.To fill this gap,this paper proposes a bi-level optimization model.A three-dimensional Macroscopic Fundamental Diagram based modeling approach is developed to capture the bi-modal congestion dynamics.A variational inequality model for the user equilibrium in mode choices is presented and solved using a double projection algorithm.A surrogate model-based algorithm is used to solve the bi-level programming problem. 展开更多
关键词 three-dimensional macroscopic fundamental diagram dynamic traffic assignment Bi-level programming model Double projection algorithm surrogate model-based algorithm
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DYNAMIC MODELING FOR AIRSHIP EQUIPPED WITH BALLONETS AND BALLAST 被引量:9
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作者 CAI Zi-li(蔡自立) Qu Wei-dong(屈卫东) XI Yu-geng(席裕庚) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第8期1072-1082,共11页
Total dynamics of an airship is modeled. The body of an airship is taken as a submerged rigid body with neutral buoyancy, i. e. , buoyancy with value equal to that of gravity, and the coupled dynamics between the body... Total dynamics of an airship is modeled. The body of an airship is taken as a submerged rigid body with neutral buoyancy, i. e. , buoyancy with value equal to that of gravity, and the coupled dynamics between the body with ballonets and ballast is considered. The total dynamics of the airship is firstly derived by Newton-Euler laws and Kirchhoff' s equations. Furthermore, by using Hamiltonian and Lagrangian semidirect product reduction theories, the dynamics is formulated as a Lie-Poisson system, or also an Euler-Poincare system. These two formulations can be exploited for the control design using energy-based methods for Hamiltonian or Lagrangian system. 展开更多
关键词 AIRsHIP dynamical modeling Kirchhoff' s equation semi-direct product reduction
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Damage Initiation and Propagation in Composites Subjected to Low-Velocity Impact:Experimental Results,3D Dynamic Damage Model,and FEM Simulations 被引量:3
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作者 JIA Wenbin WEN Weidong FANG Lei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2019年第3期488-499,共12页
A three-dimensional dynamic damage model that fits both small and large damage sizes is developed to predict impact damage initiation and propagation for each lamina of T300-carbon/epoxy laminations.First,13 specimens... A three-dimensional dynamic damage model that fits both small and large damage sizes is developed to predict impact damage initiation and propagation for each lamina of T300-carbon/epoxy laminations.First,13 specimens of the same lamination sequence are subjected to three different impact energies(10 J,15 J,and 20 J).After the impact,the laminates are inspected by the naked eye to observe the damage in the outer layers,and subsequently X-rayed to detect the inner damage.Next,the stress analysis of laminates subjected to impact loading is presented,based on the Hertz contact law and virtual displacement principle.Based on the analysis results,a three-dimensional dynamic damage model is proposed,including the Hou failure criteria and Camanho stiffness degradation model,to predict the impact damage shape and area.The numerical predictions of the damage shape and area show a relatively reasonable agreement with the experiments.Finally,the impact damage initiation and propagation for each lamina are investigated using this damage model,and the results improve the understanding of the impact process. 展开更多
关键词 COMPOsITEs IMPACT three-dimensional dynamic DAMAGE model IMPACT DAMAGE INITIATION and PROPAGATION
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Cellular automata modeling of pedestrian's crossing dynamics 被引量:6
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作者 张晋 王慧 李平 《Journal of Zhejiang University Science》 CSCD 2004年第7期835-840,共6页
Cellular automata modeling techniques and the characteristics of mixed traffic flow were used to derive the 2-dimensional model presented here for simulation of pedestrian’s crossing dynamics. A conception of “stop... Cellular automata modeling techniques and the characteristics of mixed traffic flow were used to derive the 2-dimensional model presented here for simulation of pedestrian’s crossing dynamics. A conception of “stop point” is introduced to deal with traffic obstacles and resolve conflicts among pedestrians or between pedestrians and the other vehicles on the crosswalk. The model can be easily extended, is very efficient for simulation of pedestrian’s crossing dy- namics, can be integrated into traffic simulation software, and has been proved feasible by simulation experiments. 展开更多
关键词 Cellular automata modeling Pedestrian’s crossing dynamics Traffic simulation
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Noether's theorem for non-conservative Hamilton system based on El-Nabulsi dynamical model extended by periodic laws 被引量:5
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作者 龙梓轩 张毅 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期359-367,共9页
This paper focuses on the Noether symmetries and the conserved quantities for both holonomic and nonholonomic systems based on a new non-conservative dynamical model introduced by E1-Nabulsi. First, the E1-Nabulsi dyn... This paper focuses on the Noether symmetries and the conserved quantities for both holonomic and nonholonomic systems based on a new non-conservative dynamical model introduced by E1-Nabulsi. First, the E1-Nabulsi dynamical model which is based on a fractional integral extended by periodic laws is introduced, and E1-Nabulsi-Hamilton's canoni- cal equations for non-conservative Hamilton system with holonomic or nonholonomic constraints are established. Second, the definitions and criteria of E1-Nabulsi-Noether symmetrical transformations and quasi-symmetrical transformations are presented in terms of the invariance of E1-Nabulsi-Hamilton action under the infinitesimal transformations of the group. Fi- nally, Noether's theorems for the non-conservative Hamilton system under the E1-Nabulsi dynamical system are established, which reveal the relationship between the Noether symmetry and the conserved quantity of the system. 展开更多
关键词 Noether's theorem non-conservative Hamilton system E1-Nabulsi dynamical model fractionalintegral extended by periodic laws
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Dynamic Visual Image Modeling Based on Mobile RobotSelf- Organizing Network in Internetof Things Perception Layer 被引量:1
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作者 高立 任旭鹏 李晓博 《China Communications》 SCIE CSCD 2011年第8期49-55,共7页
The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular ... The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular visual system, the real visual images of the object will be obtained. Then through the mobile self-organizing network, a three-dimensional model is rebuilt by synthesizing the returned images. On this basis, we formalize a novel algorithm for multichannel binocular visual three-dimensional images based on fast three-dimensional modeling. Compared with the method based on single binocular visual system, the new algorithm can improve the Integrity and accuracy of the dynamic three-dimensional object modeling. The simulation results show that the new method can effectively accelerate the modeling speed, improve the similarity and not increase the data size. 展开更多
关键词 IoT perception layer multigroup binocular visual dynamic visual image modeling fast three-dimensional modeling rebuild
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Demage Spreading in the Ising Model with a special Metropolis Dynamics Approach 被引量:1
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作者 LIUCe-Jun HUJia-Zhen 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第4期480-484,共5页
The time evolution of the Hamming distance (damage spreading) for the and Ising models on the square lattice is performed with a special metropolis dynamics algorithm. Two distinct regimes are observed according to ... The time evolution of the Hamming distance (damage spreading) for the and Ising models on the square lattice is performed with a special metropolis dynamics algorithm. Two distinct regimes are observed according to the temperature range for both models: a low-temperature one where the distance in the long-time limit is finite and seems not to depend on the initial distance and the system size; a high-temperature one where the distance vanishes in the long-time limit. Using the finite size scaling method, the dynamical phase transition (damage spreading transition) temperature is obtained as for the Ising model. 展开更多
关键词 s=1/2 s=1 Ising models dynamical phase transition damage spreading special metropolis dynamics
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Dynamic phase transition of ferroelectric nanotube described by a spin-1/2 transverse Ising model 被引量:1
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作者 Chundong Wang Ying Wu +1 位作者 Yulin Cao Xinying Xue 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期227-231,共5页
The dynamic phase transition properties for ferroelectric nanotube under a spin-1/2 transverse Ising model are studied under the effective field theory(EFT)with correlations.The temperature effects on the pseudo-spin ... The dynamic phase transition properties for ferroelectric nanotube under a spin-1/2 transverse Ising model are studied under the effective field theory(EFT)with correlations.The temperature effects on the pseudo-spin systems are unveiled in three-dimensional(3-D)and two-dimensional(2-D)phase diagrams.Moreover,the dynamic behaviors of exchange interactions on the 3-D and 2-D phase transitions under high temperature are exhibited.The results present that it is hard to obtain pure ferroelectric phase under high temperature;that is,the vibration of orderly pseudo-spins cannot be eliminated completely. 展开更多
关键词 ferroelectric nanotube three-dimensional(3-D)phase diagram Ising model dynamic phase transitions
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Dynamic grey model of verification cycle and lifecycle of measuring instrument and its application 被引量:4
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作者 苏海涛 杨世元 +1 位作者 董华 沈毛虎 《Journal of Central South University》 SCIE EI CAS 2005年第S2期86-89,共4页
Two dynamic grey models DGM (1, 1) for the verification cycle and the lifecycle of measuring instrument based on time sequence and frequency sequence were set up, according to the statistical feature of examination da... Two dynamic grey models DGM (1, 1) for the verification cycle and the lifecycle of measuring instrument based on time sequence and frequency sequence were set up, according to the statistical feature of examination data and weighting method. By a specific case, i.e. vernier caliper, it is proved that the fit precision and forecast precision of the models are much higher, the cycles are obviously different under different working conditions, and the forecast result of the frequency sequence model is better than that of the time sequence model. Combining dynamic grey model and auto-manufacturing case the controlling and information subsystems of verification cycle and the lifecycle based on information integration, multi-sensor controlling and management controlling were given. The models can be used in production process to help enterprise reduce error, cost and flaw. 展开更多
关键词 measuring equipment verification cycle LIFECYCLE dynamic grey model qualification rate information system
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Spatio-temporal Dynamic Simulation of Urban Land Use in Karst Areas Based on CLUE-S Model——A Case Study of Dahua Yao Nationality Autonomous County in Guangxi Zhuang Autonomous Region 被引量:1
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作者 ZHOU Xian-fang 《Asian Agricultural Research》 2012年第2期26-30,共5页
This article uses TM images in 1999 and 2006 in Dahua County,selects the driving factors having great impact on urban land use change,and conducts data processing using GIS software.It then uses CLUE-S model to simula... This article uses TM images in 1999 and 2006 in Dahua County,selects the driving factors having great impact on urban land use change,and conducts data processing using GIS software.It then uses CLUE-S model to simulate land use change pattern in 2006,and uses land use map in 2006 to test the simulation results.The results show that the simulation achieves good effect,indicating that we can use CLUE-S model to simulate the future urban land use change in karst areas,to provide scientific decision-making support for sustainable development of land use. 展开更多
关键词 CLUE-s model dynamic simulation Dahua County Karst areas Urban land
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A Framework for Exploring the Dynamics of Autonomous Work Groups in Manufacturing Organizations
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作者 Joseph W K Chan W B Lee 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期211-212,共2页
Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires... Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires a more flexible form of organization that are more adaptable to rapid cha nges in business environment such as autonomous work groups (AWGs) in order to achieve higher productivity and effectiveness. AWGs are work units responsib le for the production of goods and the provision of services. They involve team members in making decisions that are traditionally the responsibility of the sup ervisors and managers (Cohen & Bailey, 1997). Team members of AWGs are allowed t o self-regulate their behavior on jobs such as task assignments, methods for ca rrying out the work, and scheduling of activities etc. (Cohen & Ledford, 1994). For example, Motorola achieved a high organizational performance due to the succ essful implementation of AWGs in quality management (Piczak & Hauser, 1996). Xer ox also reported their operational successes based on the team-oriented work gr oups (Wageman, 1997). In recent years many organizations have replaced the traditional layers of manag ement with autonomous team-based work arrangements. Surveys indicated that the adoption of AWGs has soared in responding to the competitive business challenges . Many enterprises are making a deliberate effort to use AWGs to carry out work and operational processes as an alternative for hierarchical approaches (Lawler et al., 1995). There is a growing body of evidence that AWGs are more effective than traditionally managed groups and they contributes to organizational perform ance, such as improvement in operational performance, productivity, quality, cos t savings, employee attitude and behavior, and employee satisfaction (e.g. Pears on, 1992; Cohen & Ledford, 1994; Seers et al. 1995). Given the complexity and cognitive nature of team-based organizations, the mech anisms that the enterprises use in the development of the increasingly sophistic ated models, which can contribute to the effective functioning of AWGs, are extr emely important. The process of developing effective AWGs enables enterprises to inherent built-in intelligence of the organizations so that they will be more able to accommodate to external pressures and changes. The context of this paper is the construction of a dynamics framework and a stra tegic path for autonomous work groups in the technology-oriented manufacturing organization re-design. The framework is a conceptual one drawn from the litera ture survey. The importance of studying autonomous work groups for today’s manuf acturing organizations is claimed. Based on the General System Theory (GST), the characterization of AWGs is addressed. Three-dimensional domains such as t echnical content, service content, and relationship content are identified. A st rategic path is proposed to guide the organizations how the development of AWGs progresses at different levels of maturity that are associated with organization al effectiveness and performance. The utility of the model for AWGs is expected to provide technology-oriented organizations with a strategic path to achieve h igher organizational performance. 展开更多
关键词 autonomous work group three-dimensional dynamic s model general systems theory EFFECTIVENEss maturity level
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THE APPLICATION OF DISCRETE ELEMENT METHOD IN SOLVING THREE-DIMENTIONAL IMPACT DYNAMICS PROBLEMS 被引量:7
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作者 Liu Kaixin Gao Lingtian (Department of Mechanics and Engineering Science,Peking University,Beijing 100871,China) 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第3期256-261,共6页
A three-dimensional discrete element model of the connective type is presented. Moreover,a three-dimensional numerical analysis code,which can carry out the transitional pro- cess from connective model(for continuum)t... A three-dimensional discrete element model of the connective type is presented. Moreover,a three-dimensional numerical analysis code,which can carry out the transitional pro- cess from connective model(for continuum)to contact model(for non-continuum),is developed for simulating the mechanical process from continuum to non-continuum.The wave propagation process in a concrete block(as continuum)made of cement grout under impact loading is numer- ically simulated with this code.By comparing its numerical results with those by LS-DYNA,the calculation accuracy of the model and algorithm is proved.Furthermore,the failure process of the concrete block under quasi-static loading is demonstrated,showing the basic dynamic tran- sitional process from continuum to non-continuum.The results of calculation can be displayed by animation.The damage modes are similar to the experimental results.The two numerical examples above prove that our model and its code are powerful and efficient in simulating the dynamic failure problems accompanying the transition from continuum to non-continuum.It also shows that the discrete element method(DEM)will have broad prospects for development and application. 展开更多
关键词 discrete element method three-dimensional model IMPACT stress wave dynamic failure
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Dynamic behaviors of water contained in calcium-silicate-hydrate gel at different temperatures studied by quasi-elastic neutron scattering spectroscopy 被引量:2
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作者 易洲 邓沛娜 +1 位作者 张丽丽 李华 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第10期271-278,共8页
The dynamic behaviors of water contained in calcium-silicate-hydrate(C-S-H) gel with different water content values from 10%to 30%(by weight),are studied by using an empirical diffusion model(EDM) to analyze the... The dynamic behaviors of water contained in calcium-silicate-hydrate(C-S-H) gel with different water content values from 10%to 30%(by weight),are studied by using an empirical diffusion model(EDM) to analyze the experimental data of quasi-elastic neutron scattering(QENS) spectra at measured temperatures ranging from 230 K to 280 K.In the study,the experimental QENS spectra with the whole Q-range are considered.Several important parameters including the bound/immobile water elastic coefficient A,the bound water index BWI,the Lorentzian with a half-width at half-maximum(HWHM) Γ;(Q) and Γ;(Q),the self-diffusion coefficients D;and D;of water molecules,the average residence times τ;and τ;,and the proton mean squared displacement(MSD)(u;) are obtained.The results show that the QENS spectra can be fitted very well not only for small Q(≤1 A;) but also for large Q.The bound/immobile water fraction in a C-S-H gel sample can be shown by the fitted BWI.The distinction between bound/immobile and mobile water,which includes confined water and ultra-confined water,can be seen by the fitted MSD.All the MSD tend to be the smallest value below 0.25 A;(the MSD of bound/immobile water) as the Q increases to 1.9 A;no matter what the temperature and water content are.Furthermore,by the abrupt changes of the fitted values of D;,τ;,and Γ;(Q),a crossover temperature at 250 K,namely the liquid-to-crystal-like transition temperature,can be identified for confined water in large gel pores(LGPs) and/or small gel pores(SGPs) contained in the C-S-H gel sample with 30% water content. 展开更多
关键词 dynamics of water quasi-elastic neutron scattering spectra empirical diffusion model C–s–H gel pastes
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Synchronization Phenomena Investigation of a New Nonlinear Dynamical System 4D by Gardano’s and Lyapunov’s Methods 被引量:2
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作者 Abdulsattar Abdullah Hamad Ahmed S.Al-Obeidi +2 位作者 Enas H.Al-Taiy Osamah Ibrahim Khalaf Dac-Nhuong Le 《Computers, Materials & Continua》 SCIE EI 2021年第3期3311-3327,共17页
Synchronization is one of the most important characteristics of dynamic systems.For this paper,the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems.The fin... Synchronization is one of the most important characteristics of dynamic systems.For this paper,the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems.The findings have allowed authors to develop two analytical approaches using the second Lyapunov(Lyp)method and the Gardanomethod.Since the Gardano method does not involve the development of special positive Lyp functions,it is very efficient and convenient to achieve excessive systemSYCR phenomena.Error is overcome by using Gardano and overcoming some problems in Lyp.Thus we get a great investigation into the convergence of error dynamics,the authors in this paper are interested in giving numerical simulations of the proposed model to clarify the results and check them,an important aspect that will be studied is Synchronization Complete hybrid SYCR and anti-Synchronization,by making use of the Lyapunov expansion analysis,a proposed control method is developed to determine the actual.The basic idea in the proposed way is to receive the evolution of between two methods.Finally,the present model has been applied and showing in a new attractor,and the obtained results are compared with other approximate results,and the nearly good coincidence was obtained. 展开更多
关键词 CHAOs Lu model ANTI-sYNCHRONIZATION hybrid synchronization Gardano’s method nonlinear dynamical system
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AN ANALYTICAL SOLUTION FOR THREE-DIMENSIONAL DIFFRACTION OF PLANE P-WAVES BY A HEMISPHERICAL ALLUVIAL VALLEY WITH SATURATED SOIL DEPOSITS 被引量:2
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作者 Zhao Chenggang Dong Jun Gao Fuping 《Acta Mechanica Solida Sinica》 SCIE EI 2006年第2期141-151,共11页
An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion te... An analytical solution for the three-dimensional scattering and diffraction of plane P-waves by a hemispherical alluvial valley with saturated soil deposits is developed by employing Fourier-Bessel series expansion technique. Unlike previous studies, in which the saturated soil deposits were simulated with the single-phase elastic theory, in this paper, they are simulated with Biot's dynamic theory for saturated porous media, and the half space is assumed as a single-phase elastic medium. The effects of the dimensionless frequency, the incidence angle of P-wave and the porosity of soil deposits on the surface displacement magnifications of the hemispherical alluvial valley are investigated. Numerical results show that the existence of a saturated hemispherical alluvial valley has much influence on the surface displacement magnifications. It is more reasonable to simulate soil deposits with Biot's dynamic theory when evaluating the displacement responses of a hemispherical alluvial valley with an incidence of P-waves. 展开更多
关键词 Biot's dynamic theory three-dimensional scattering hemispherical alluvial valley analytical solution
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Three-Dimensional Water-Quality Simulation for River Based on VOF Method 被引量:1
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作者 Ao Xuefei Wang Xiaoling +2 位作者 Song Mingrui Deng Shaohui Li Songmin 《Transactions of Tianjin University》 EI CAS 2016年第5期426-433,共8页
In the present study, considering the transport and transformation processes of variables, a threedimensional water quality model for the river system was established, which coupled the volume of fluid(VOF) method wit... In the present study, considering the transport and transformation processes of variables, a threedimensional water quality model for the river system was established, which coupled the volume of fluid(VOF) method with the k-ε turbulence mathematical model. Then, the water hydrodynamic characteristics and transport processes for BOD_5, NH_(3^-)N and TP were analyzed. The results showed that the water surface of convex bank was a little lower than that of concave bank due to the centrifugal force near the bend, and most concentrations were inferior to the type Ⅴ standard indexes of surface water environmental quality. The model validation indicated that the errors between the simulated and monitored values were comparatively small, satisfying the application demands and providing scientific basis and decision support for the restoration and protection of water quality. 展开更多
关键词 three-dimensional WATER QUALITY model volume of FLUID method k-ε turbulence mathematical model RIVER WATER QUALITY computational FLUID dynamics
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Dynamic Analysis of Propulsion Mechanism Directly Driven by Wave Energy for Marine Mobile Buoy 被引量:8
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作者 YU Zhenjiang ZHENG Zhongqiang +1 位作者 YANG Xiaoguang CHANG Zongyu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期710-715,共6页
Marine mobile buoy(MMB) have many potential applications in the maritime industry and ocean science.Great progress has been made,however the technology in this area is far from maturity in theory and faced with many... Marine mobile buoy(MMB) have many potential applications in the maritime industry and ocean science.Great progress has been made,however the technology in this area is far from maturity in theory and faced with many difficulties in application.A dynamic model of the propulsion mechanism is very necessary for optimizing the parameters of the MMB,especially with consideration of hydrodynamic force.The principle of wave-driven propulsion mechanism is briefly introduced.To set a theory foundation for study on the MMB,a dynamic model of the propulsion mechanism of the MMB is obtained.The responses of the motion of the platform and the hydrofoil are obtained by using a numerical integration method to solve the ordinary differential equations.A simplified form of the motion equations is reached by omitting terms with high order small values.The relationship among the heave motion of the buoy,stiffness of the elastic components,and the forward speed can be obtained by using these simplified equations.The dynamic analysis show the following:The angle of displacement of foil is fairly small with the biggest value around 0.3 rad;The speed of mobile buoy and the angle of hydrofoil increased gradually with the increase of heave motion of buoy;The relationship among heaven motion,stiffness and attack angle is that heave motion leads to the angle change of foil whereas the item of speed or push function is determined by vertical velocity and angle,therefore,the heave motion and stiffness can affect the motion of buoy significantly if the size of hydrofoil is kept constant.The proposed model is provided to optimize the parameters of the MMB and a foundation is laid for improving the performance of the MMB. 展开更多
关键词 propulsion mechanism marine mobile buoy dynamic model hydrodynamics Morision's equation
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