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Performance of composite foundations with different load transfer platforms and substratum stiffness over silty clay
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作者 ZHANG Shuming LIU Yan +3 位作者 YUAN Shengyang LIU Xianfeng JIANG Guanlu LIU Junyan 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1761-1774,共14页
The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of foundations.It is crucial to understand the stress dis... The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of foundations.It is crucial to understand the stress distribution across the embankment width and the behaviour of unreinforced foundations.Thus,five centrifuge tests were conducted to examine the bearing and deformation behaviours of NPRS(Non-Connected Piled Raft Systems)and GRPS(GeosyntheticReinforced Pile-Supported systems)with varying substratum stiffness,then a comparative analysis was conducted on embankment settlement,pressures underneath the embankments,and axial forces along the piles.The results indicated that greater substratum stiffness correlates with reduced settlement and deformation at various depths.Deformation occurring 5 meters from the embankment toe includes settlement in NPRS and upward movement in GRPS.The potential sliding surface is primarily located within the embankment in NPRS,whereas it may extend through both the embankment and foundation in GRPS.The pile-soil stress ratio and efficiency in NPRS are higher than in GRPS across the embankment.The axial force borne by end-bearing piles is significantly greater than that by floating piles.As the buried depth increases,the axial force in GRPS initially rises then declines,whereas in NPRS,it remains relatively constant within a certain range before decreasing.This study aids in assessing the applicability of composite foundations in complex railway environments and provides a reference for procedural measures under similar conditions. 展开更多
关键词 Centrifuge modelling Composite foundation Failure mode Load transfer platform SUBSTRATUM STIFFNESS Silty clay
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Quafu-Qcover:Explore combinatorial optimization problems on cloud-based quantum computers
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作者 许宏泽 庄伟峰 +29 位作者 王正安 黄凯旋 时运豪 马卫国 李天铭 陈驰通 许凯 冯玉龙 刘培 陈墨 李尚书 杨智鹏 钱辰 靳羽欣 马运恒 肖骁 钱鹏 顾炎武 柴绪丹 普亚南 张翼鹏 魏世杰 增进峰 李行 龙桂鲁 金贻荣 于海峰 范桁 刘东 胡孟军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期104-115,共12页
We introduce Quafu-Qcover,an open-source cloud-based software package developed for solving combinatorial optimization problems using quantum simulators and hardware backends.Quafu-Qcover provides a standardized and c... We introduce Quafu-Qcover,an open-source cloud-based software package developed for solving combinatorial optimization problems using quantum simulators and hardware backends.Quafu-Qcover provides a standardized and comprehensive workflow that utilizes the quantum approximate optimization algorithm(QAOA).It facilitates the automatic conversion of the original problem into a quadratic unconstrained binary optimization(QUBO)model and its corresponding Ising model,which can be subsequently transformed into a weight graph.The core of Qcover relies on a graph decomposition-based classical algorithm,which efficiently derives the optimal parameters for the shallow QAOA circuit.Quafu-Qcover incorporates a dedicated compiler capable of translating QAOA circuits into physical quantum circuits that can be executed on Quafu cloud quantum computers.Compared to a general-purpose compiler,our compiler demonstrates the ability to generate shorter circuit depths,while also exhibiting superior speed performance.Additionally,the Qcover compiler has the capability to dynamically create a library of qubits coupling substructures in real-time,utilizing the most recent calibration data from the superconducting quantum devices.This ensures that computational tasks can be assigned to connected physical qubits with the highest fidelity.The Quafu-Qcover allows us to retrieve quantum computing sampling results using a task ID at any time,enabling asynchronous processing.Moreover,it incorporates modules for results preprocessing and visualization,facilitating an intuitive display of solutions for combinatorial optimization problems.We hope that Quafu-Qcover can serve as an instructive illustration for how to explore application problems on the Quafu cloud quantum computers. 展开更多
关键词 quantum cloud platform combinatorial optimization problems quantum software
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Efficient Inverse Analysis for Solving a Coupled Conduction,Convection and Radiation Problem Involving Non⁃gray Participating Media
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作者 HE Zheng CAO Zhenkun +2 位作者 CHENG Xiang CUI Miao LIU Kun 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第5期621-631,共11页
The presence of non-gray radiative properties in a reheating furnace’s medium that absorbs,emits,and involves non-gray creates more complex radiative heat transfer problems.Furthermore,it adds difficulty to solving t... The presence of non-gray radiative properties in a reheating furnace’s medium that absorbs,emits,and involves non-gray creates more complex radiative heat transfer problems.Furthermore,it adds difficulty to solving the coupled conduction,convection,and radiation problem,leading to suboptimal efficiency that fails to meet real-time control demands.To overcome this difficulty,comparable gray radiative properties of non-gray media are proposed and estimated by solving an inverse problem.However,the required iteration numbers by using a least-squares method are too many and resulted in a very low inverse efficiency.It is necessary to present an efficient method for the equivalence.The Levenberg-Marquardt algorithm is utilized to solve the inverse problem of coupled heat transfer,and the gray-equivalent radiative characteristics are successfully recovered.It is our intention that the issue of low inverse efficiency,which has been observed when the least-squares method is employed,will be resolved.To enhance the performance of the Levenberg-Marquardt algorithm,a modification is implemented for determining the damping factor.Detailed investigations are also conducted to evaluate its accuracy,stability of convergence,efficiency,and robustness of the algorithm.Subsequently,a comparison is made between the results achieved using each method. 展开更多
关键词 inverse problem coupled heat transfer problem Levenberg-Marquardt algorithm
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A transfer learning enhanced physics-informed neural network for parameter identification in soft materials
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作者 Jing’ang ZHU Yiheng XUE Zishun LIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第10期1685-1704,共20页
Soft materials,with the sensitivity to various external stimuli,exhibit high flexibility and stretchability.Accurate prediction of their mechanical behaviors requires advanced hyperelastic constitutive models incorpor... Soft materials,with the sensitivity to various external stimuli,exhibit high flexibility and stretchability.Accurate prediction of their mechanical behaviors requires advanced hyperelastic constitutive models incorporating multiple parameters.However,identifying multiple parameters under complex deformations remains a challenge,especially with limited observed data.In this study,we develop a physics-informed neural network(PINN)framework to identify material parameters and predict mechanical fields,focusing on compressible Neo-Hookean materials and hydrogels.To improve accuracy,we utilize scaling techniques to normalize network outputs and material parameters.This framework effectively solves forward and inverse problems,extrapolating continuous mechanical fields from sparse boundary data and identifying unknown mechanical properties.We explore different approaches for imposing boundary conditions(BCs)to assess their impacts on accuracy.To enhance efficiency and generalization,we propose a transfer learning enhanced PINN(TL-PINN),allowing pre-trained networks to quickly adapt to new scenarios.The TL-PINN significantly reduces computational costs while maintaining accuracy.This work holds promise in addressing practical challenges in soft material science,and provides insights into soft material mechanics with state-of-the-art experimental methods. 展开更多
关键词 soft material parameter identification physics-informed neural network(PinN) transfer learning inverse problem
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The Major Problems and the Governmental Role in Chinese Rural Land Transfer 被引量:8
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作者 ZHANG Cen-cheng 《Asian Agricultural Research》 2011年第7期62-65,共4页
On the basis of clarifying and defining rural land transfer, the necessity of rural land transfer is analyzed. Land transfer is the necessity in terms of promoting agricultural scale operation and improving production... On the basis of clarifying and defining rural land transfer, the necessity of rural land transfer is analyzed. Land transfer is the necessity in terms of promoting agricultural scale operation and improving production efficiency; proving opportunities for narrowing urban and rural gap; realizing rural surplus labor transfer and facilitating urbanization. Major problems in the existing rural land transfer are analyzed:unclear laws and regulations and rural land transfer lacks relevant legal protection;rural social security system is imperfect and can not solve farmers' worries after land transfer; farmers and local governments are restricted by traditional ideas and it is hard to carry out the land transfer policies; rural system construction is relatively backward and the rural land transfer market is immature. Countermeasures on the governmental behaviors in rural land transfer are put forward: stipulating relevant administrative laws and regulations and perfecting the political system of rural land transfer; perfecting rural social security system and solving farmers' worries after land transfer; changing the ideas and working style of local officials and leading farmers to form the scientific land transfer outlook;and vigorously promoting the construction of system and positively cultivating rural land transfer market. 展开更多
关键词 Rural land transfer Major problems Governmental behaviors China
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A Mathematical Model to Solve Bio-Heat Transfer Problems through a Bio-Heat Transfer Equation with Quadratic Temperature-Dependent Blood Perfusion under a Constant Spatial Heating on Skin Surface 被引量:1
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作者 Emmanuel Kengne Idir Mellal +1 位作者 Mariem Ben Hamouda Ahmed Lakhssassi 《Journal of Biomedical Science and Engineering》 2014年第9期721-730,共10页
We consider the one-dimensional bio-heat transfer equation with quadratic temperature-dependent blood perfusion, which governs the temperature distribution inside biological tissues. Using an extended mapping method w... We consider the one-dimensional bio-heat transfer equation with quadratic temperature-dependent blood perfusion, which governs the temperature distribution inside biological tissues. Using an extended mapping method with symbolic computation, we obtain the exact analytical thermal traveling wave solution, which describes the non-uniform temperature distribution inside the bodies. The found exact solution is used to investigate the temperature distribution in the tissues. It is found that the surrounding medium with higher temperature does not necessarily imply that the tissue will quickly (after a short duration of heating process) reach the desired temperature. It is also found that increased perfusion causes a decline in local temperature. 展开更多
关键词 Bio-Heat transfer problemS Pennes Bio-Heat Model TEMPERATURE-DEPENDENT Blood PERFUSION thermal therapy Extended Mapping Method
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Inquiry into Problems of Farmers' Employment under the Condition of Land Transfer
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作者 JIN Li-fu,RAN Shuang-quan College of Humanities,Jiangsu University,Zhenjiang 212013,China 《Asian Agricultural Research》 2011年第5期22-27,共6页
This paper emphasizes the urgency of solving the problems of farmers' employment under the condition of land transfer,indicating that solving the problems of farmers' employment is the necessary requirement of... This paper emphasizes the urgency of solving the problems of farmers' employment under the condition of land transfer,indicating that solving the problems of farmers' employment is the necessary requirement of land transfer,the actual requirement of constructing well-off society comprehensively,and the objective requirement of transforming developmental model.The characteristics of the problems of farmers' employment under the condition of land transfer are as follows:the rural surplus labor forces increase,and the ubiquitous unemployment is urgent;the employment room of farmers is narrow,and the structural unemployment is serious;the ability of farmers' employment is poor,and recessive unemployment has a large proportion;the situation of farmers' employment is not so sanguine,and the policy unemployment is frequent.This paper points out the causes of farmers' employment problems under the situation of land transfer as follows:in terms of analysis of subjective factors,farmers' self-employment ability is yet to be underpinned;in terms of analysis of objective factors,the relevant mechanism of government is unsound.Finally,corresponding countermeasures and suggestions are put forward as follows:establish the mechanism of farmer traceability analysis under the condition of land transfer;strengthen the training of farmers' skills;reinforce the publicity and education of farmers' employment concept;promote the process of urbanization and construct the employment vehicle of farmers;adjust the industrial structure in rural areas and expand the internal employment in rural areas;improve macro regulation and improve the employment environment for farmers. 展开更多
关键词 LAND transfer FARMER the problemS of EMPLOYMENT Ch
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Study on the Installation and Construction Technology of the Transfer Stairway on the Track Platform on Bridge——Taking the Construction of the Jialing River Bridge in Zengjiayan of Chongqing City as an Example
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作者 Shiping Li 《Journal of Architectural Research and Development》 2021年第1期8-12,共5页
The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technol... The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technology of installing and replacing with tunnel under special conditions is discussed to provide reference for bridge construction. 展开更多
关键词 Track platform on bridge transfer stairway Bridge construction
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Regularization Method to the Parameter Identification of Interfacial Heat Transfer Coefficient and Properties during Casting Solidification 被引量:4
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作者 隋大山 崔振山 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第4期511-516,共6页
The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly. The inverse he... The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly. The inverse heat conduction method can be used to identify the mentioned above parameters based on the temperature measurement data. This paper presented a new inverse method according to Tikhonov regularization theory. A regularization functional was established and the regularization parameter was deduced, the Newton-Raphson iteration method was used to solve the equations. One detailed case was solved to identify the thermal conductivity and specific heat of sand mold and interfacial heat transfer coefficient (IHTC) at the meantime. This indicates that the regularization method is very efficient in decreasing the sensitivity to the temperature measurement data, overcoming the ill-posedness of the inverse heat conduction problem (IHCP) and improving the stability and accuracy of the results. As a general inverse method, it can be used to identify not only the material physical properties but also the initial and boundary conditions' parameters. 展开更多
关键词 CASTinG inVERSE HEAT conduction problem parameter identification REGULARIZATION method inTERFACIAL HEAT transfer COEFFICIENT
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Effects of Second-Order Sum-and Difference-Frequency Wave Forces on the Motion Response of a Tension-Leg Platform Considering the Set-down Motion 被引量:3
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作者 WANG Bin TANG Yougang CAI Runbo 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第2期311-319,共9页
This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave fo... This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave force is calculated using the full-field quadratic transfer function(QTF). The coupled effect of the horizontal motions, such as surge, sway and yaw motions, and the set-down motion are taken into consideration by the nonlinear restoring matrix. The time-domain analysis with 50-yr random sea state is performed. A comparison of the results of different case studies is made to assess the influence of second-order wave force on the motions of the platform. The analysis shows that the second-order wave force has a major impact on motions of the TLP. The second-order difference-frequency wave force has an obvious influence on the low-frequency motions of surge and sway, and also will induce a large set-down motion which is an important part of heave motion. Besides, the second-order sum-frequency force will induce a set of high-frequency motions of roll and pitch. However, little influence of second-order wave force is found on the yaw motion. 展开更多
关键词 tension-leg platform random WAVE SECOND-ORDER WAVE force quadratic transfer function sum-frequency differencefrequency set-down MOTION
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Authentication and Access Control in RFID Based Logistics-customs Clearance Service Platform 被引量:4
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作者 Hui-Fang Deng Wen Deng +1 位作者 Han Li Hong-Ji Yang 《International Journal of Automation and computing》 EI 2010年第2期180-189,共10页
The content security requirements of a radio frequency identification (RFID) based logistics-customs clearance service platform (LCCSP) are analysed in this paper. Then, both the unified identity authentication an... The content security requirements of a radio frequency identification (RFID) based logistics-customs clearance service platform (LCCSP) are analysed in this paper. Then, both the unified identity authentication and the access control modules are designed according to those analyses. Finally, the unified identity authentication and the access control on the business level are implemented separately. In the unified identity authentication module, based on an improved Kerberos-based authentication approach, a new control transfer method is proposed to solve the sharing problem of tickets among different servers of different departments. In the access control module, the functions of access controls are divided into different granularities to make the access control management more flexible. Moreover, the access control module has significant reference value for user management in similar systems. 展开更多
关键词 Content security unified identity authentication control transfer access control logistics-customs clearance service platform (LCCSP).
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A Numerical Method on Inverse Determination of Heat Transfer Coefficient Based on Thermographic Temperature Measurement 被引量:6
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作者 范春利 孙丰瑞 杨立 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第6期901-908,共8页
The heat transfer coefficient in a multidimensional heat conduction problem is obtained from the solution of the inverse heat conduction problem based on the thermographic temperature measurement. The modified one-dim... The heat transfer coefficient in a multidimensional heat conduction problem is obtained from the solution of the inverse heat conduction problem based on the thermographic temperature measurement. The modified one-dimensional correction method (MODCM), along with the finite volume method, is employed for both two- and three-dimensional inverse problems. A series of numerical experiments are conducted in order to verify the effectiveness of the method. In addition, the effect of the temperature measurement error, the ending criterion of the iteration, etc. on the result of the inverse problem is investigated. It is proved that the method is a simple, stable and accurate one that can solve successfully the inverse heat conduction problem. 展开更多
关键词 inverse heat conduction problem heat transfer coefficient finite volume method modified one-dimensional correction method measurement error
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Applying Job Shop Scheduling to SMEs Manufacturing Platform to Revitalize B2B Relationship
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作者 Yeonjee Choi Hyun Suk Hwang Chang Soo Kim 《Computers, Materials & Continua》 SCIE EI 2023年第3期4901-4916,共16页
A small and medium enterprises(SMEs)manufacturing platform aims to perform as a significant revenue to SMEs and vendors by providing scheduling and monitoring capabilities.The optimal job shop scheduling is generated ... A small and medium enterprises(SMEs)manufacturing platform aims to perform as a significant revenue to SMEs and vendors by providing scheduling and monitoring capabilities.The optimal job shop scheduling is generated by utilizing the scheduling system of the platform,and a minimum production time,i.e.,makespan decides whether the scheduling is optimal or not.This scheduling result allows manufacturers to achieve high productivity,energy savings,and customer satisfaction.Manufacturing in Industry 4.0 requires dynamic,uncertain,complex production environments,and customer-centered services.This paper proposes a novel method for solving the difficulties of the SMEs manufacturing by applying and implementing the job shop scheduling system on a SMEs manufacturing platform.The primary purpose of the SMEs manufacturing platform is to improve the B2B relationship between manufacturing companies and vendors.The platform also serves qualified and satisfactory production opportunities for buyers and producers by meeting two key factors:early delivery date and fulfillment of processing as many orders as possible.The genetic algorithm(GA)-based scheduling method results indicated that the proposed platform enables SME manufacturers to obtain optimized schedules by solving the job shop scheduling problem(JSSP)by comparing with the real-world data from a textile weaving factory in South Korea.The proposed platform will provide producers with an optimal production schedule,introduce new producers to buyers,and eventually foster relationships and mutual economic interests. 展开更多
关键词 Manufacturing platform job shop scheduling problem(JSSP) genetic algorithm optimization textile process
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基于云计算的引调水工程星载TD-InSAR地表形变监测
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作者 万鹏 韩贤权 +1 位作者 谭勇 秦朋 《长江科学院院报》 CSCD 北大核心 2024年第10期206-214,共9页
针对时间序列InSAR计算量大、时效性低、传统D-InSAR精度不高的问题,提出了TD-InSAR连续像对干涉测量方法,并利用HyP3云计算平台实现了长距离引调水工程沿线地表形变连续干涉像对快速分析。以珠江三角洲水资源配置工程为研究区,以传统PS... 针对时间序列InSAR计算量大、时效性低、传统D-InSAR精度不高的问题,提出了TD-InSAR连续像对干涉测量方法,并利用HyP3云计算平台实现了长距离引调水工程沿线地表形变连续干涉像对快速分析。以珠江三角洲水资源配置工程为研究区,以传统PS-InSAR监测结果为参照数据对TD-InSAR地表形变探测精度进行了验证。试验结果表明:TD-InSAR取得的地表形变速率与PS-InSAR趋势一致,决定系数R 2>0.7,精度相比传统D-InSAR方法提高了52.6%;基于云计算的TD-InSAR地表形变监测方法降低了时序分析的计算量,提高了时序分析的时效性,适用于大范围的地表形变快速普查分析。 展开更多
关键词 地表形变监测 合成孔径雷达干涉测量(inSAR) 引调水工程 HyP3云计算平台 地表形变快速普查
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On the Monge–Kantorovich Mass Transfer Problem in Higher Dimensions
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作者 Xiao Jun LU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2024年第8期1989-2004,共16页
This paper mainly investigates the approximation of a global maximizer of the Monge–Kantorovich mass transfer problem in higher dimensions through the approach of nonlinear partial differential equations with Dirichl... This paper mainly investigates the approximation of a global maximizer of the Monge–Kantorovich mass transfer problem in higher dimensions through the approach of nonlinear partial differential equations with Dirichlet boundary.Using an approximation mechanism,the primal maximization problem can be transformed into a sequence of minimization problems.By applying the systematic canonical duality theory,one is able to derive a sequence of analytic solutions for the minimization problems.In the final analysis,the convergence of the sequence to an analytical global maximizer of the primal Monge–Kantorovich problem will be demonstrated. 展开更多
关键词 Monge-Kantorovich mass transfer singular variational problem canonical duality theory
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Exact analytical solution to three-dimensional phase change heat transfer problems in biological tissues subject to freezing
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作者 李方方 刘静 乐恺 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期63-72,共10页
Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green func... Analytically solving a three-dimensional (3-D) bioheat transfer problem with phase change during a freezing process is extremely difficult but theoretically important. The moving heat source model and the Green function method are introduced to deal with the cryopreservation process of in vitro biomaterials. Exact solutions for the 3-D temperature transients of tissues under various boundary conditions, such as totally convective cooling, totally fixed temperature cooling and a hybrid between them on tissue surfaces, are obtained. Furthermore, the cryosurgical process in living tissues subject to freezing by a single or multiple cryoprobes is also analytically solved. A closed-form analytical solution to the bioheat phase change process is derived by considering contributions from blood perfusion heat transfer, metabolic heat generation, and heat sink of a cryoprobe. The present method is expected to have significant value for analytically solving complex bioheat transfer problems with phase change. 展开更多
关键词 three-dimensional phase change heat transfer problem CRYOSURGERY CRYOPRESERVATION moving heat source model bioheat transfer Green's function analytical solution
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SOLVING 2-D NONLINEAR COUPLED HEAT AND MOISTURE TRANSFER PROBLEMS VIA A SELF-ADAPTIVE PRECISE ALGORITHM IN TIME DOMAIN
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作者 杨海天 刘岩 邬瑞锋 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第7期848-854,共7页
A self-adaptive precise algorithm in the time domain was employed to solve 2-D nonlinear coupled heat and moisture transfer problems. By expanding variables at a discretized time interval, the variations of variables ... A self-adaptive precise algorithm in the time domain was employed to solve 2-D nonlinear coupled heat and moisture transfer problems. By expanding variables at a discretized time interval, the variations of variables can be described more precisely,and a nonlinear coupled initial and boundary value problem was converted into a series of recurrent linear boundary value problems which are solved by FE technique. In the computation, no additional assumption and the nonlinear iteration are required, and a criterion for self-adaptive computation is proposed to maintain sufficient computing accuracy for the change sizes of time steps. In the numerical comparison, the variations of material properties with temperature, moisture content, and both temperature and moisture content are taken into account, respectively. Satisfactory results have been obtained, indicating that the proposed approach is capable of dealing with complex nonlinear problems. 展开更多
关键词 finite element nonlinear transfer problem time stepping self-adaptive computation
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Accurate reconstruction of the optical parameter distribution in participating medium based on the frequency-domain radiative transfer equation
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作者 乔要宾 齐宏 +1 位作者 赵方舟 阮立明 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期144-152,共9页
Reconstructing the distribution of optical parameters in the participating medium based on the frequency-domain radiative transfer equation (FD-RTE) to probe the internal structure of the medium is investigated in t... Reconstructing the distribution of optical parameters in the participating medium based on the frequency-domain radiative transfer equation (FD-RTE) to probe the internal structure of the medium is investigated in the present work. The forward model of FD-RTE is solved via the finite volume method (FVM). The regularization term formatted by the generalized Gaussian Markov random field model is used in the objective function to overcome the ill-posed nature of the inverse problem. The multi-start conjugate gradient (MCG) method is employed to search the minimum of the objective function and increase the efficiency of convergence. A modified adjoint differentiation technique using the collimated radiative intensity is developed to calculate the gradient of the objective function with respect to the optical parameters. All simulation results show that the proposed reconstruction algorithm based on FD-RTE can obtain the accurate distributions of absorption and scattering coefficients. The reconstructed images of the scattering coefficient have less errors than those of the absorption coefficient, which indicates the former are more suitable to probing the inner structure. 展开更多
关键词 inverse problem adjoint differentiation multi-start conjugate gradient method frequency-domainradiative transfer equation
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Quasi-Static Problem of Thermoelasticity for Thermosensitive Infinite Circular Cylinder of Complex Heat Exchange
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作者 Halyna Harmatij Marta Król Vasyl Popovycz 《Advances in Pure Mathematics》 2013年第4期430-437,共8页
Nonlinear nonstationary heat conduction problem for infinite circular cylinder under a complex heat transfer taking into account the temperature dependence of thermophysical characteristics of materials is solved nume... Nonlinear nonstationary heat conduction problem for infinite circular cylinder under a complex heat transfer taking into account the temperature dependence of thermophysical characteristics of materials is solved numerically by the method of lines. Directing it to the Cauchy’s problem for systems of ordinary differential equations studied feature which takes place on the cylinder axis. Taken into account the dependence on the temperature coefficient of heat transfer that the different interpretation of its physical content makes it possible to consider both convective and convective-ray or heat ray. Using the perturbation method, the corresponding thermoelasticity problem taking into account the temperature dependence of mechanical properties of the material is construed. The influence of the temperature dependence of the material on the distribution of temperature field and thermoelastic state of infinite circular cylinder made of titanium alloy Ti-6Al-4V by radiant heat transfer through the outer surface has been analyzed. 展开更多
关键词 theRMOELASTIC State Heat transfer Boundary Value problem
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Estimation of overall heat transfer coefficient of cooling system in RF capacitive hyperthermia
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作者 Seyed Ali Aghayan Dariush Sardari +1 位作者 Seyed Rabii Mahdi Mahdavi Mohammad Hasan Zahmatkesh 《Journal of Biomedical Science and Engineering》 2013年第5期509-517,共9页
The study presented in this article involves the estimation of the overall heat transfer coefficient of cooling system in RF capacitive hyperthermia treatment using inverse problem based on the conjugate gradient meth... The study presented in this article involves the estimation of the overall heat transfer coefficient of cooling system in RF capacitive hyperthermia treatment using inverse problem based on the conjugate gradient method to provide improved distribution of temperature. The temperature data computed numerically from the direct problem using the finite difference time domain method are used to simulate the temperature measurements. The effects of the errors and sensor positions upon the precision of the estimated results are also considered. The results show that a reasonable estimation of the unknown can be obtained. Finally, measurements in a tissue-equivalent phantom are employed to appraise the reliability of the presented method. The comparison of computed data with measurements shows a good agreement between numerical and experimental results. 展开更多
关键词 ESTIMATION HYPERtheRMIA inVERSE problem PHANTOM Overall Heat transfer COEFFICIENT
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