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A 3-DOF Pseudo-Rigid-Body Model for Tension-Based Compliant Bistable Mechanisms 被引量:1
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作者 CHEN Guimin GAO Hongwei JIA Jianyuan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第2期149-153,共5页
Compliant bistable mechanisms, devices with two distinct stable equilibrium positions, are used in a variety of applications, such as switches, clasps, and valves. Many kinds of compliant bistable mechanisms were prop... Compliant bistable mechanisms, devices with two distinct stable equilibrium positions, are used in a variety of applications, such as switches, clasps, and valves. Many kinds of compliant bistable mechanisms were proposed and studied during the past decade. Among them, tension-based compliant bistable mechanisms, that incorporate tension pivots as their flexible members, feature in short travel distance and low power consuming. So far, the design of this kind of bistable mechanisms is done using finite element method through trial and error, thus is time-consuming. By treating the tension pivots as fixed-guided segments and their elongation as a spring, we developed a novel three degree-of-freedom (3-DOF) pseudo-rigid-body model (PRBM) for this kind of bistable mechanisms. The principle of virtual work is used to derive the force-deflection relationship of the PRBM model. The comparison between the PRBM results and the experimental results of the force-deflection characteristics shows that the PRBM can predict not only the bistable behavior of the tension-based bistable mechanisms, but also their soft spring-like post-bistable behavior and the spring-like force-deflection characteristics when pulling in the reverse direction from the as-fabricated position, which is called reverse behavior. The 3-DOF PRBM can be used to design and identify tension-based bistable mechanisms. Using the PRBM instead of the trial-and-error method can greatly reduce the development time of this kind of bistable mechanisms. 展开更多
关键词 compliant bistable mechanism pseudo-rigid-body model tension pivot
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Study upon Modeling and Visualization of 3D Geologic Body Based on Generalized Tri-Prism 被引量:3
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作者 唐勇 江南 《Journal of Landscape Research》 2010年第9期1-3,55,共4页
According to the characteristics of bore data,a model of 3D geologic body with generalized tri-prism as the primitive modeling element is constructed while the modeling process and key algorithms of modeling are prese... According to the characteristics of bore data,a model of 3D geologic body with generalized tri-prism as the primitive modeling element is constructed while the modeling process and key algorithms of modeling are presented here in detail.Using this method,the original bore data go through Delaunay triangulation to generate irregular triangular network on the surface,and then links stratum segments on the adjoining bores in session to form tri-prisms which would be pinched out.Finally stratified 3D geologic body model is built by an iterated search which searches for consecutive layer of the same property.The result shows that this method can effectively simulate stratified stratum modeling. 展开更多
关键词 3D geological body modelING VISUALIZATION GENERALIZED tri-prism DELAUNAY triangulation
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Evaluation on Spot Weld Models in Structural Dynamic Analysis of Automotive Body in White 被引量:9
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作者 LIANG Jianyong LIANG Jun FANG Guodong PAN Zimin LI Wei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第1期84-90,共7页
Spot weld models are widely used in finite element analysis(FEA) of automotive body in white(BIW) to predict static,dynamic,durability and other characteristics of automotive BIW.However,few researches are done on... Spot weld models are widely used in finite element analysis(FEA) of automotive body in white(BIW) to predict static,dynamic,durability and other characteristics of automotive BIW.However,few researches are done on evaluation of the validity of these spot weld models in structural dynamic analysis of BIW.To evaluate the validity and accuracy of spot weld models in structural dynamic analysis of BIW,two object functions,error function and deviation function,are introduced innovatively.Modal analysis of Two-panel and Double-hat structures,which are the dominated structures in BIW,is conducted,and the values of these two object functions are obtained.Based on the values of object functions,the validity of these spot weld models are evaluated.It is found that the area contact method(ACM2) and weld element connection(CWELD) can give more precise prediction in modal analysis of these two classical structures,thus are more applicable to structural dynamic analysis of automotive BIW.Modal analysis of a classical BIW is performed,which further confirms this evaluation.The error function and deviation function proposed in this research can give guidance on the adaptability of spot weld models in structural dynamic analysis of BIW.And this evaluation method can also be adopted in evaluation of other finite element models in static,dynamic and other kinds of analysis for automotive structures. 展开更多
关键词 spot weld model structural dynamic analysis modal analysis two-panel structure double-hat structure body in white
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Modeling Method of Automotive Body CAN/LIN Nets Application Protocol Based on Object-oriented Colored Petri Net 被引量:8
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作者 FANG Hua HAN Jianghong and LIU Xiaoping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第6期999-1006,共8页
Recently automotive nets are adopted to solve increasing problems in automotive electronic systems.Technologies of automotive local area network from CAN and LIN can solve the problems of the increasing of wire bunch ... Recently automotive nets are adopted to solve increasing problems in automotive electronic systems.Technologies of automotive local area network from CAN and LIN can solve the problems of the increasing of wire bunch weight and lack in module installation space.However,the multilayer automotive nets software becomes more and more complex,and the development expense is difficult to predict and to keep in check.In this paper,the modeling method of hierarchical automotive nets and the substitution operation based on object-oriented colored Petri net(OOCPN) are proposed.The OOCPN model which analyzes the software structure and validates the collision mechanism of CAN/LIN bus can speed the automobile system development.First,the subsystems are divided and modeled by object-oriented Petri net(OOPN).According to the sets of message sharing relations,the message ports among them are set and the communication gate transitions are defined.Second,the OOPN model is substituted step by step until the inner objects in the automotive body control modules(BCM) are indivisible and colored by colored Petri net(CPN).And the color subsets mark the node messages for the collision mechanism.Third,the OOCPN model of the automotive body CAN/LIN nets is assembled,which keeps the message sets and the system can be expanded.The proposed model is used to analyze features of information sharing among the objects,and it is also used to describe each subsystem real-time behavior of processing messages and implemental device controllers operating,and puts forward a reasonable software framework for the automotive body control subsystem.The research can help to design the communication model in the automotive body system effectively and provide a convenient and rapid way for developing the logical hierarchy software. 展开更多
关键词 automotive body CAN/LIN bus information sharing object-oriented colored Petri net modeling
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Gray Model of Human Body Shape 被引量:1
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作者 陈文飞 李明菊 《Journal of China Textile University(English Edition)》 EI CAS 2000年第4期43-45,共3页
In order to determine the control dimensions of human body in pattern construction and provide the basis for size specification in clothing industry, a gray model is described and established in the application of pre... In order to determine the control dimensions of human body in pattern construction and provide the basis for size specification in clothing industry, a gray model is described and established in the application of predicting size specification. By comparing the features of gray model and regression model, it is proved that the former has many advantages over the latter, i.e. more practical and more effective in this application. So it is strongly suggested to apply the innovative gray model instead of the traditional regression model to facilitate the calculation procedure in pattern construction. 展开更多
关键词 CLOTHING HUMAN body MEASUREMENT GRAY model
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An Analysis Model of Sports Human Body Based on Computer Vision Tracking Technology 被引量:3
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作者 Mingzhu Yuan 《International Journal of Technology Management》 2017年第4期71-73,共3页
This paper proposes the analysis model of sports human body based on computer vision tracking technology. Visual target tracking is an important research field of the computer vision, motion trajectory and it can prov... This paper proposes the analysis model of sports human body based on computer vision tracking technology. Visual target tracking is an important research field of the computer vision, motion trajectory and it can provide not only the goal, to provide the initial data movement analysis, scene understanding, behavior or the event detection in intelligent surveillance, human-computer interaction, robot visual navigation and motion recognition based on field has a broad application prospect. For this reason, it is possible to consider the use of a large number of unlabeled samples to assist the training classifier to improve its performance. This type of machine learning method using both labeled and that unlabeled samples is called the semi-supervised learning. This paper proposes the novel idea of the related research topics to propose the new perspective of the model that will be later give us the novel idea of making it efficient for further development of sport science. 展开更多
关键词 Human body Analysis model Computer Vision Tracking Technology
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Geological characteristics and models of fault-foldfracture body in deep tight sandstone of the second member of Upper Triassic Xujiahe Formation in Xinchang structural belt of Sichuan Basin,SW China 被引量:1
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作者 LIU Junlong LIU Zhongqun +8 位作者 LIU Zhenfeng LIU Yali SHEN Baojian XIAO Kaihua BI Youyi WANG Xiaowen WANG Ail FAN Lingxiao LI Jitongl 《Petroleum Exploration and Development》 SCIE 2023年第3期603-614,共12页
In the second member of the Upper Triassic Xujiahe Formation(T_(3)x_(2))in the Xinchang area,western Sichuan Basin,only a low percent of reserves has been recovered,and the geological model of gas reservoir sweet spot... In the second member of the Upper Triassic Xujiahe Formation(T_(3)x_(2))in the Xinchang area,western Sichuan Basin,only a low percent of reserves has been recovered,and the geological model of gas reservoir sweet spot remains unclear.Based on a large number of core,field outcrop,test and logging-seismic data,the T_(3)x_(2) gas reservoir in the Xinchang area is examined.The concept of fault-fold-fracture body(FFFB)is proposed,and its types are recognized.The main factors controlling fracture development are identified,and the geological models of FFFB are established.FFFB refers to faults,folds and associated fractures reservoirs.According to the characteristics and genesis,FFFBs can be divided into three types:fault-fracture body,fold-fracture body,and fault-fold body.In the hanging wall of the fault,the closer to the fault,the more developed the effective fractures;the greater the fold amplitude and the closer to the fold hinge plane,the more developed the effective fractures.Two types of geological models of FFFB are established:fault-fold fracture,and matrix storage and permeability.The former can be divided into two subtypes:network fracture,and single structural fracture,and the later can be divided into three subtypes:bedding fracture,low permeability pore,and extremely low permeability pore.The process for evaluating favorable FFFB zones was formed to define favorable development targets and support the well deployment for purpose of high production.The study results provide a reference for the exploration and development of deep tight sandstone oil and gas reservoirs in China. 展开更多
关键词 fault-fold-fracture body fracture control factor genetic characteristics geological model deep layer tight sandstone Xinchang structural belt Upper Triassic Xujiahe Formation Sichuan Basin
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Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model 被引量:5
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作者 戴瑜 刘少军 李力 《China Ocean Engineering》 SCIE EI 2010年第1期145-160,共16页
In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with som... In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force dements built on the theory of terramechanics acting on each discrete dement. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particMar structure design of the pilot miner, the special characteristics of the seafioor soil and the hydrodynamic force of near-seafloor currnt, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches. 展开更多
关键词 deep-ocean mining system self-propelled seafloor pilot miner single-body model multi-body model discretized track-terrain interaction model dynamic analysis
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Rapid 3D human body modeling based on Kinect technology 被引量:1
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作者 HE Kunlin XU Yong +1 位作者 MAO Aihua LI Guiqing 《Computer Aided Drafting,Design and Manufacturing》 2013年第1期7-13,共7页
The 3D shape of the human body is useful for applications in fitness, games and apparel. Accurate body scanners, howev- er, are expensive, limiting the availability of 3D body models. In this paper, we focus on the hu... The 3D shape of the human body is useful for applications in fitness, games and apparel. Accurate body scanners, howev- er, are expensive, limiting the availability of 3D body models. In this paper, we focus on the human body 3D modeling using one Kinect sensor modeling method. To get the human body model fast, three steps in rapid modeling of the human body are carried out. Firstly, according to anthropometric parameters, the standard model is parameterized; Secondly, the Kinect depth image of the human body model is gotten through, then, by using the PCL library the point cloud data is processed and matched, and the human body model is optimized; Finally, the realistic human body model is obtained with the rapid integration of the standard model and PCL library. 展开更多
关键词 human body model rapid modeling PCL Kinect sensor anthropometric parameters
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Development of a Model for Water and Heat Exchange Between the Atmosphere and a Water Body
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作者 孙菽芬 颜金凤 +1 位作者 夏南 孙长海 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第5期927-938,共12页
A model for studying the heat and mass exchange between the atmosphere and a water body is developed, in which the phase change process of water freezing in winter and melting in summer and the function of the convect... A model for studying the heat and mass exchange between the atmosphere and a water body is developed, in which the phase change process of water freezing in winter and melting in summer and the function of the convective mixing process are taken into consideration. The model uses enthalpy rather than temperature as the predictive variable. It helps to set up governing equations more concisely, to deal with the phase change process more easily, and make the numerical scheme simpler. The model is verified by observed data from Lake Kinneret for a non-frozen lake in summer time, and Lake Lower Two Medicine for a frozen lake in winter time. Reasonably good agreements between the model simulations and observed data indicate that the model can serve as a component for a water body in a land surface model. In order to more efficiently apply the scheme in a climate system model, a sensitivity study of various division schemes with less layers in the vertical direction in the water body is conducted. The results of the study show that the division with around 10 vertical layers could produce a prediction accuracy that is comparable to the fine division with around 40 layers. 展开更多
关键词 water body model ENTHALPY convective mixing model validation
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Quantum theory-based physical model of the human body in TCM 被引量:1
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作者 SONG Shuna SHE Zhensu 《Digital Chinese Medicine》 2022年第4期354-359,共6页
In the study,a quantum resonant cavity model based on wave-particle duality was proposed for the explanation of the dynamic processes of essence,vigor,and spirit in the human body in traditional Chinese medicine(TCM).... In the study,a quantum resonant cavity model based on wave-particle duality was proposed for the explanation of the dynamic processes of essence,vigor,and spirit in the human body in traditional Chinese medicine(TCM).It is assumed that there is a macro human order parameter(wave function),and its dynamics are governed by a macro potential field reflecting influences from heaven,earth,and society,and satisfy the generalized Schrodinger equation.This proposed model was applied in the study to interpret basic concepts of human body in TCM,with an aim to unfold the TCM development in the future. 展开更多
关键词 Quantum-resonant cavity Traditional Chinese medicine(TCM) Physical model of the human body Complex system The order parameter
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Irregular surface seismic forward modeling by a body-fitted rotated–staggered-grid finite-difference method 被引量:4
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作者 Cheng Jing-Wang Fan Na +1 位作者 Zhang You-Yuan Lü Xiao-Chun 《Applied Geophysics》 SCIE CSCD 2018年第3期420-431,共12页
Finite-difference(FD) methods are widely used in seismic forward modeling owing to their computational efficiency but are not readily applicable to irregular topographies. Thus, several FD methods based on the transfo... Finite-difference(FD) methods are widely used in seismic forward modeling owing to their computational efficiency but are not readily applicable to irregular topographies. Thus, several FD methods based on the transformation to curvilinear coordinates using body-fitted grids have been proposed, e.g., stand staggered grid(SSG) with interpolation, nonstaggered grid, rotated staggered grid(RSG), and fully staggered. The FD based on the RSG is somewhat superior to others because it satisfies the spatial distribution of the wave equation without additional memory and computational requirements; furthermore, it is simpler to implement. We use the RSG FD method to transform the firstorder stress–velocity equation in the curvilinear coordinates system and introduce the highprecision adaptive, unilateral mimetic finite-difference(UMFD) method to process the freeboundary conditions of an irregular surface. The numerical results suggest that the precision of the solution is higher than that of the vacuum formalism. When the minimum wavelength is low, UMFD avoids the surface wave dispersion. We compare FD methods based on RSG, SEM, and nonstaggered grid and infer that all simulation results are consistent but the computational efficiency of the RSG FD method is higher than the rest. 展开更多
关键词 FINITE DIFFERENCE FORWARD modeling GRID staggered rotated body-fitted SURFACE free BOUNDARY
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COMPUTER SYSTEM FOR GEOMETRIC MODELING OF GEOLOGIC BODIES AND APPLICATIONS
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作者 Dai, Tagen Mao, Xiancheng 《中国有色金属学会会刊:英文版》 EI CSCD 1998年第4期179-184,共6页
INTRODUCTIONThemodelsofgeometricmodelingofgeologicbodiesbeargeometric,topologicalandattributeinformation[1... INTRODUCTIONThemodelsofgeometricmodelingofgeologicbodiesbeargeometric,topologicalandattributeinformation[1].Bymeansofcomput... 展开更多
关键词 GEOLOGIC body data structure MATHEMATICAL model automatic PLOTTING
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Dynamic model for landsliding monitoring under rigid body assumption
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作者 朱建军 丁晓利 陈永奇 《中国有色金属学会会刊:英文版》 CSCD 2001年第2期301-306,共6页
Based on the assumption that the slope bodies are rigid, the dynamic model of the landsiding (forward model) was put forward. According to the dynamic model, the system equations of Kalman filter were constituted. The... Based on the assumption that the slope bodies are rigid, the dynamic model of the landsiding (forward model) was put forward. According to the dynamic model, the system equations of Kalman filter were constituted. The mechanical status of a slope was hence combined with the monitoring data by Kalman filter. The model uncertainties or model errors could also be considered through some fictitious observation equations. Different from existed methods, the presented method can make use for not only the statistic information contained in the data but also the information provided by the mechanical and geological aspect of slopes. At last a numerical example was given out to show the feasibility of the method. [ 展开更多
关键词 dynamic model KALMAN filter RIGID body LANDSLIDE MONITORING
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Research on Dynamic Model of the Human Body
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作者 张春林 王光泉 路敦勇 《Journal of Beijing Institute of Technology》 EI CAS 2005年第2期184-187,共4页
After summarizing the current situation of the research on human body modeling, a new dynamic model containing 5 equivalent masses has been proposed and the corresponding dynamic equations has been deduced too. By usi... After summarizing the current situation of the research on human body modeling, a new dynamic model containing 5 equivalent masses has been proposed and the corresponding dynamic equations has been deduced too. By using this new model, more detailed information about the situation of the human body under impact and vibration can be obtained. The new model solves the problem that transmission functions of forces inside the human body can't be deduced by using 3-equivalent-mass model. It will find its usage in many applications. 展开更多
关键词 BIOMECHANICAL human body modeling dynamic model
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PRELIMINARY STUDY ON GEOMETRIC MODELING OF GEOLOGIC BODY
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作者 Mao Xiancheng and Dai TagenCollege of Resource, Environment and Civil Engineering,Central South University of Technology, Changsha 410083, P. R. China 《中国有色金属学会会刊:英文版》 CSCD 1998年第2期174-177,共4页
PRELIMINARYSTUDYONGEOMETRICMODELINGOFGEOLOGICBODY①MaoXianchengandDaiTagenColegeofResource,EnvironmentandCivi... PRELIMINARYSTUDYONGEOMETRICMODELINGOFGEOLOGICBODY①MaoXianchengandDaiTagenColegeofResource,EnvironmentandCivilEnginering,Centr... 展开更多
关键词 GEOLOGIC body geometeric modelING computeraided design
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New model of body force in electromagnetic stirring gas tungsten-arc welding
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作者 罗键 《中国有色金属学会会刊:英文版》 CSCD 2001年第3期391-394,共4页
After measuring arc electrical current density distribution in gas tungsten arc welding(GTAW) with a probe method, the new expression of body force and model of LD10CS aluminum alloy weld pool are put forward for the ... After measuring arc electrical current density distribution in gas tungsten arc welding(GTAW) with a probe method, the new expression of body force and model of LD10CS aluminum alloy weld pool are put forward for the first time in GTAW with additional longitudinal magnetic field controlling. The influence of additional longitudinal magnetic field on body force is discussed by electromagnetic principle. This study provides the basis to study fluid flow of the weld pools and arc welding technique with electromagnetic controlling. [ 展开更多
关键词 GTAW body force model longitudinal magnetic field weld pool
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Understanding many-body physics in one dimension from the Lieb–Liniger model 被引量:1
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作者 姜玉铸 陈洋洋 管习文 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第5期16-31,共16页
This article presents an elementary introduction on various aspects of the prototypical integrable model the LiebLiniger Bose gas ranging from the cooperative to the collective features of many-body phenomena. In 1963... This article presents an elementary introduction on various aspects of the prototypical integrable model the LiebLiniger Bose gas ranging from the cooperative to the collective features of many-body phenomena. In 1963, Lieb and Liniger first solved this quantum field theory many-body problem using Bethe's hypothesis, i.e., a particular form of wavefunction introduced by Bethe in solving the one-dimensional Heisenberg model in 1931. Despite the Lieb-Liniger model is arguably the simplest exactly solvable model, it exhibits rich quantum many-body physics in terms of the aspects of mathematical integrability and physical universality. Moreover, the Yang-Yang grand canonical ensemble description for the model provides us with a deep understanding of quantum statistics, thermodynamics, and quantum critical phenomena at the many-body physical level. Recently, such fundamental physics of this exactly solved model has been attracting growing interest in experiments. Since 2004, there have been more than 20 experimental papers that rbported novel observations of different physical aspects of the Lieb--Liniger model in the laboratory. So far the observed results are in excellent agreement with results obtained using the analysis of this simplest exactly solved model. Those experimental observations reveal the unique beauty of integrability. 展开更多
关键词 many-body physics Lieb-Liniger model
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Fast forward modeling of gravity anomalies for two-dimensional bodies of arbitrary shape and density distribution
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作者 Chen Xin Chen Long-Wei +1 位作者 Luo Tian-Ya Xiong Bin 《Applied Geophysics》 SCIE CSCD 2020年第5期776-783,902,903,共10页
A fast and high precision spatial domain algorithm is presented for forward modeling of two-dimensional(2D)body gravity anomalies of arbitrary shape and density distribution.The new algorithm takes advantage of the co... A fast and high precision spatial domain algorithm is presented for forward modeling of two-dimensional(2D)body gravity anomalies of arbitrary shape and density distribution.The new algorithm takes advantage of the convolution properties of the expression for 2D gravity anomalies,uses a rectangular cell as a grid subdivision unit,and then 2D bodies with irregular cross-sections are approximated by a combination of 2D bodies with a rectangular cross section.The closed-form expression is used to calculate the gravitational anomalies of the combination of 2D bodies with a rectangular cross section.To improve computing effi ciency,the new algorithm uses a fast algorithm for the implementation of the Toeplitz matrix and vector multiplication.The synthetic 2D models with rectangular and circular cross-sections and constant and variable densities are designed to evaluate the computational accuracy and speed of the new algorithm.The experiment results show that the computation costs less than 6 s for a grid subdivision with 10000×10000 elements.Compared to the traditional forward modeling methods,the proposed method significantly improved computational effi ciency while guaranteeing computational accuracy. 展开更多
关键词 two-dimensional bodies gravity anomalies forward modeling Toeplitz matrix
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Identification of Mixtures of Two Types of Body Fluids Using the Multiplex Methylation System and Random Forest Models
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作者 Han-xiao WANG Xiao-zhao LIU +3 位作者 Xi-miao HE Chao XIAO Dai-xin HUANG Shao-hua YI 《Current Medical Science》 SCIE CAS 2023年第5期908-918,共11页
Objective Body fluid mixtures are complex biological samples that frequently occur in crime scenes,and can provide important clues for criminal case analysis.DNA methylation assay has been applied in the identificatio... Objective Body fluid mixtures are complex biological samples that frequently occur in crime scenes,and can provide important clues for criminal case analysis.DNA methylation assay has been applied in the identification of human body fluids,and has exhibited excellent performance in predicting single-source body fluids.The present study aims to develop a methylation SNaPshot multiplex system for body fluid identification,and accurately predict the mixture samples.In addition,the value of DNA methylation in the prediction of body fluid mixtures was further explored.Methods In the present study,420 samples of body fluid mixtures and 250 samples of single body fluids were tested using an optimized multiplex methylation system.Each kind of body fluid sample presented the specific methylation profiles of the 10 markers.Results Significant differences in methylation levels were observed between the mixtures and single body fluids.For all kinds of mixtures,the Spearman’s correlation analysis revealed a significantly strong correlation between the methylation levels and component proportions(1:20,1:10,1:5,1:1,5:1,10:1 and 20:1).Two random forest classification models were trained for the prediction of mixture types and the prediction of the mixture proportion of 2 components,based on the methylation levels of 10 markers.For the mixture prediction,Model-1 presented outstanding prediction accuracy,which reached up to 99.3%in 427 training samples,and had a remarkable accuracy of 100%in 243 independent test samples.For the mixture proportion prediction,Model-2 demonstrated an excellent accuracy of 98.8%in 252 training samples,and 98.2%in 168 independent test samples.The total prediction accuracy reached 99.3%for body fluid mixtures and 98.6%for the mixture proportions.Conclusion These results indicate the excellent capability and powerful value of the multiplex methylation system in the identification of forensic body fluid mixtures. 展开更多
关键词 body fluid identification MIXTURE mixing ratio DNA methylation multiplex assay random forest model
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