期刊文献+
共找到1,683篇文章
< 1 2 85 >
每页显示 20 50 100
Modeling texture evolution during rolling process of AZ31 magnesium alloy with elasto-plastic self consistent model 被引量:4
1
作者 黄诗尧 张少睿 +1 位作者 李大永 彭颖红 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第6期1348-1354,共7页
To gain a better understanding about texture evolution during rolling process of AZ31 alloy, polycrystalline plasticity model was implemented into the explicit FE package, ABAQUS/Explicit by writing a user subroutine ... To gain a better understanding about texture evolution during rolling process of AZ31 alloy, polycrystalline plasticity model was implemented into the explicit FE package, ABAQUS/Explicit by writing a user subroutine VUMAT. For each individual grain in the polycrystalline aggregate, the rate dependent model was adopted to calculate the plastic shear strain increment in combination with the Voce hardening law to describe the hardening response, the lattice reorientation caused by slip and twinning were calculated separately due to their different mechanisms. The elasto-plastic self consistent (EPSC) model was employed to relate the response of individual grain to the response of the polycrystalline aggregate. Rolling processes of AZ31 sheet and as-cast AZ31 alloy were simulated respectively. The predicted texture distributions are in aualitative a^reement with experimental results. 展开更多
关键词 AZ31 alloy texture rolling process elasto-plastic self consistent (EPSC) model
在线阅读 下载PDF
Relativistic Consistent Angular-Momentum Projected Shell-Model:Angular-Momentum Projection 被引量:3
2
作者 LIYan-Song LONGGui-Lu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第4期579-582,共4页
The angular-momentum projection part of RECAPS is presented.Application of RECAPS to some deformed nuclei is also presented.
关键词 relativistic consistent angular-momentum projected shell-model angular-momentum projection projected shell model RECAPS-RMF
在线阅读 下载PDF
Relativistic Consistent Angular-Momentum Projected Shell-Model: Relativistic Mean Field 被引量:3
3
作者 LIYan-Song LONGGui-Lu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期429-434,共6页
We develop a relativistic nuclear structure model, relativistic consistent angular-momentum projected shell-model (RECAPS), which combines the relativistic mean-field theory with the angular-momentum projection method... We develop a relativistic nuclear structure model, relativistic consistent angular-momentum projected shell-model (RECAPS), which combines the relativistic mean-field theory with the angular-momentum projection method. In this new model, nuclear ground-state properties are first calculated consistently using relativistic mean-field (RMF) theory. Then angular momentum projection method is used to project out states with good angular momentum from a few important configurations. By diagonalizing the hamiltonian, the energy levels and wave functions are obtained. This model is a new attempt for the understanding of nuclear structure of normal nuclei and for the prediction of nuclear properties of nuclei far from stability. In this paper, we will describe the treatment of the relativistic mean field. A computer code, RECAPS-RMF, is developed. It solves the relativistic mean field with axial-symmetric deformation in the spherical harmonic oscillator basis. Comparisons between our calculations and existing relativistic mean-field calculations are made to test the model. These include the ground-state properties of spherical nuclei <SUP>16</SUP>O and <SUP>208</SUP>Pb, the deformed nucleus <SUP>20</SUP>Ne. Good agreement is obtained. 展开更多
关键词 relativistic consistent angular-momentum projected shell-model relativistic mean field projected shell model PECAPS-RMF
在线阅读 下载PDF
DISSIPATION-BASED CONSISTENT RATE-DEPENDENT MODEL FOR CONCRETE 被引量:1
4
作者 Fei Leng Gao Lin 《Acta Mechanica Solida Sinica》 SCIE EI 2010年第2期147-155,共9页
An energy-dissipation based viscoplastic consistency model is presented to describe the performance of concrete under dynamic loading. The development of plasticity is started with the thermodynamic hypotheses in orde... An energy-dissipation based viscoplastic consistency model is presented to describe the performance of concrete under dynamic loading. The development of plasticity is started with the thermodynamic hypotheses in order that the model may have a sound theoretical background. Independent hardening and softening and the rate dependence of concrete are described separately for tension and compression. A modified implicit backward Euler integration scheme is adopted for the numerical computation. Static and dynamic behavior of the material is illustrated with certain numerical examples at material point level and structural level, and compared with existing experimental data. Results validate the effectiveness of the model. 展开更多
关键词 constitutive model VISCOPLASTICITY consistency model energy dissipation rate dependency CONCRETE backward Euler scheme
在线阅读 下载PDF
Thermodynamic Consistency of Plate and Shell Mathematical Models in the Context of Classical and Non-Classical Continuum Mechanics and a Thermodynamically Consistent New Thermoelastic Formulation 被引量:3
5
作者 Karan S. Surana Sri Sai Charan Mathi 《American Journal of Computational Mathematics》 2020年第2期167-220,共54页
Inclusion of dissipation and memory mechanisms, non-classical elasticity and thermal effects in the currently used plate/shell mathematical models require that we establish if these mathematical models can be derived ... Inclusion of dissipation and memory mechanisms, non-classical elasticity and thermal effects in the currently used plate/shell mathematical models require that we establish if these mathematical models can be derived using the conservation and balance laws of continuum mechanics in conjunction with the corresponding kinematic assumptions. This is referred to as thermodynamic consistency of the mathematical models. Thermodynamic consistency ensures thermodynamic equilibrium during the evolution of the deformation. When the mathematical models are thermodynamically consistent, the second law of thermodynamics facilitates consistent derivations of constitutive theories in the presence of dissipation and memory mechanisms. This is the main motivation for the work presented in this paper. In the currently used mathematical models for plates/shells based on the assumed kinematic relations, energy functional is constructed over the volume consisting of kinetic energy, strain energy and the potential energy of the loads. The Euler’s equations derived from the first variation of the energy functional for arbitrary length when set to zero yield the mathematical model(s) for the deforming plates/shells. Alternatively, principle of virtual work can also be used to derive the same mathematical model(s). For linear elastic reversible deformation physics with small deformation and small strain, these two approaches, based on energy functional and the principle of virtual work, yield the same mathematical models. These mathematical models hold for reversible mechanical deformation. In this paper, we examine whether the currently used plate/shell mathematical models with the corresponding kinematic assumptions can be derived using the conservation and balance laws of classical or non-classical continuum mechanics. The mathematical models based on Kirchhoff hypothesis (classical plate theory, CPT) and first order shear deformation theory (FSDT) that are representative of most mathematical models for plates/shells are investigated in this paper for their thermodynamic consistency. This is followed by the details of a general and higher order thermodynamically consistent plate/shell thermoelastic mathematical model that is free of a priori consideration of kinematic assumptions and remains valid for very thin as well as thick plates/shells with comprehensive nonlinear constitutive theories based on integrity. Model problem studies are presented for small deformation behavior of linear elastic plates in the absence of thermal effects and the results are compared with CPT and FSDT mathematical models. 展开更多
关键词 Plate and Shell Mathematical models Energy Functional Thermodynamic Consistency Classical Continuum Mechanics Non-Classical Continuum Mechanics Internal Rotations Cosserat Rotations Principle of Virtual Work
在线阅读 下载PDF
Thermodynamically consistent model for diblock copolymer melts coupled with an electric field
6
作者 Xiaowen Shen Qi Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第4期710-714,共5页
We present a thermodynamically consistent model for diblock copolymer melts coupled with an electric field derived using the Onsager linear response theory.We compare the model with the thermodynamically inconsistent ... We present a thermodynamically consistent model for diblock copolymer melts coupled with an electric field derived using the Onsager linear response theory.We compare the model with the thermodynamically inconsistent one previously used for the coupled system to highlight their differences in describing transient dynamics. 展开更多
关键词 thermodynamical consistency diblock copolymer melts electric field phase field model
原文传递
Measurement.Based Spatial-Consistent Channel Modeling Involving Clusters of Scatterers
7
作者 YIN Xuefeng ZHANG Nan +1 位作者 Stephen Wang CHENG Xiang 《ZTE Communications》 2017年第1期28-34,共7页
In this paper,the conventional method of establishing spatial channel models(SCMs)based on measurements is extended by including clusters-of-scatterers(CoSs)that exist along propagation paths.The channel models result... In this paper,the conventional method of establishing spatial channel models(SCMs)based on measurements is extended by including clusters-of-scatterers(CoSs)that exist along propagation paths.The channel models resulted utilizing this new method are applicable for generating channel realizations of reasonable spatial consistency,which is required for designing techniques and systems of the fifth generation wireless communications.The scatterers’locations are estimated from channel measurement data obtained using large-scale antenna arrays through the Space-Alternating Generalized Expectation-Maximization(SAGE)algorithm derived under a spherical wavefront assumption.The stochastic properties of CoSs extracted from real measurement data in an indoor environment are presented. 展开更多
关键词 channel modeling large-scale antenna array spatial consistency space-alternating generalized expectation-maximization(SAGE) algorithm spherical wavefront
在线阅读 下载PDF
Self-Consistent Model for Pulsed Direct-Current N_2 Glow Discharge
8
作者 刘成森 王德真 《Plasma Science and Technology》 SCIE EI CAS CSCD 2005年第2期2745-2747,共3页
A self-consistent analysis of a pulsed direct-current (DC) N2 glow discharge is presented. The model is based on a numerical solution of the continuity equations for electron and ions coupled with Poisson's equati... A self-consistent analysis of a pulsed direct-current (DC) N2 glow discharge is presented. The model is based on a numerical solution of the continuity equations for electron and ions coupled with Poisson's equation. The spatial-temporal variations of ionic and electronic densities and electric field are obtained. The electric field structure exhibits all the characteristic regions of a typical glow discharge (the cathode fall, the negative glow, and the positive column). Current-voltage characteristics of the discharge can be obtained from the model. The calculated current-voltage results using a constant secondary electron emission coefficient for the gas pressure 133.32 Pa are in reasonable agreement with experiment. 展开更多
关键词 pulsed DC glow discharge plasma nitriding self-consistent model
在线阅读 下载PDF
The Development of Artificial Intelligence:Toward Consistency in the Logical Structures of Datasets,AI Models,Model Building,and Hardware?
9
作者 Li Guo Jinghai Li 《Engineering》 2025年第7期13-17,共5页
The aim of this article is to explore potential directions for the development of artificial intelligence(AI).It points out that,while current AI can handle the statistical properties of complex systems,it has difficu... The aim of this article is to explore potential directions for the development of artificial intelligence(AI).It points out that,while current AI can handle the statistical properties of complex systems,it has difficulty effectively processing and fully representing their spatiotemporal complexity patterns.The article also discusses a potential path of AI development in the engineering domain.Based on the existing understanding of the principles of multilevel com-plexity,this article suggests that consistency among the logical structures of datasets,AI models,model-building software,and hardware will be an important AI development direction and is worthy of careful consideration. 展开更多
关键词 CONSISTENCY datasets model building ai models artificial intelligence ai explore potential directions HARDWARE artificial intelligence
在线阅读 下载PDF
Modeling and Simulation of Epidemics Using q-Diffusion-Based SEIR Framework with Stochastic Perturbations
10
作者 Amani Baazeem Muhammad Shoaib Arif +1 位作者 Yasir Nawaz Kamaleldin Abodayeh 《Computer Modeling in Engineering & Sciences》 2025年第6期3463-3489,共27页
The numerical approximation of stochastic partial differential equations(SPDEs),particularly those including q-diffusion,poses considerable challenges due to the requirements for high-order precision,stability amongst... The numerical approximation of stochastic partial differential equations(SPDEs),particularly those including q-diffusion,poses considerable challenges due to the requirements for high-order precision,stability amongst random perturbations,and processing efficiency.Because of their simplicity,conventional numerical techniques like the Euler-Maruyama method are frequently employed to solve stochastic differential equations;nonetheless,they may have low-order accuracy and lower stability in stiff or high-resolution situations.This study proposes a novel computational scheme for solving SPDEs arising from a stochastic SEIR model with q-diffusion and a general incidence rate function.A proposed computational scheme can be used to solve stochastic partial differential equations.For spatial discretization,a compact scheme is chosen.The compact scheme can provide a sixth-order accurate solution.The proposed scheme can be considered an extension of the Euler Maruyama method.Stability and consistency in the mean square sense are also provided.For application purposes,the stochastic SEIR model is considered using q-diffusion effects.The scheme is used to solve the stochastic model and compared with the Euler-Maruyama method.The scheme is also compared with nonstandard finite difference method for solving deterministic models.In both cases,it performs better than existing schemes.Incorporating q-diffusion further enhanced the model’s ability to represent realistic spatial-temporal disease dynamics,especially in scenarios where classical diffusion is insufficient. 展开更多
关键词 Computational scheme STABILITY CONSISTENCY SEIR epidemic model q-diffusion saturated incidence rate
在线阅读 下载PDF
Teaching-Learning-Assessment Consistency of the 5E Teaching Model and Its Application of English Picture Book Teaching in Elementary School
11
作者 HE Ai-jing YUAN Ling-na HUANG Lin-lin 《Journal of Literature and Art Studies》 2025年第7期580-586,共7页
The 5E model includes Engagement,Exploration,Explanation,Elaboration,and Evaluation,with“Evaluation”at the end,conflicting with teaching learning-evaluation consistency.Thus,formative levaluation is integrated into ... The 5E model includes Engagement,Exploration,Explanation,Elaboration,and Evaluation,with“Evaluation”at the end,conflicting with teaching learning-evaluation consistency.Thus,formative levaluation is integrated into the first four stages,and a summative evaluation table is designed for the fifth,enabling students to self-evaluate and reflect.Elementary school English picture book teaching is used as an example to demonstrate the optimized model's application. 展开更多
关键词 teaching and evaluation consistency 5E teaching model elementary English picture book teaching
在线阅读 下载PDF
基于VSG的交流微电网自触发功率经济分配隐私保护策略
12
作者 杨珺 范晏通 秦杰 《电力系统自动化》 北大核心 2026年第1期118-129,共12页
针对高比例可再生能源并网导致的微电网惯性下降问题,聚焦于虚拟同步发电机控制交流微电网的功率经济分配与数据安全协同优化问题展开研究。首先,提出了一种融合模型预测控制的改进增量成本一致性算法,对功率不平衡值进行计算,打破了传... 针对高比例可再生能源并网导致的微电网惯性下降问题,聚焦于虚拟同步发电机控制交流微电网的功率经济分配与数据安全协同优化问题展开研究。首先,提出了一种融合模型预测控制的改进增量成本一致性算法,对功率不平衡值进行计算,打破了传统一致性算法中领导节点需要计算全局信息的限制。其次,提出了一种双维度协同的自触发隐私保护策略,并采用差分隐私机制对交互信息进行噪声注入以解决数据泄露问题。同时,结合事件驱动的自触发机制以减少计算负担并降低通信和加密成本。最后,通过4机7节点系统进行仿真验证。结果表明,所提自触发隐私保护策略显著减少了通信资源与计算资源,提升了微电网控制的鲁棒性与隐私安全性。 展开更多
关键词 微电网 虚拟同步发电机 隐私保护 功率经济分配 模型预测控制 一致性算法
在线阅读 下载PDF
Consistency of Water Production Function Models of Two Crops 被引量:1
13
作者 樊鹏 王莹 +1 位作者 杨青伟 杨喜会 《Agricultural Science & Technology》 CAS 2016年第1期12-14,共3页
On basis of test information, the research performed analysis on water production function models of two crops, which indicated that water model of crops in whole growth stage and water model of crops indifferent grow... On basis of test information, the research performed analysis on water production function models of two crops, which indicated that water model of crops in whole growth stage and water model of crops indifferent growth stages have consistency as well as differences, providing references for optimization of irrigation water. Meanwhile, the research analyzed the deficiency of optimization on irrigation water for crops just by Jensen model. 展开更多
关键词 Water production function Parabolic model Jensen model CONSISTENCY
在线阅读 下载PDF
基于Modelica语言的PDE与DAE问题的一致表示 被引量:2
14
作者 李志华 张慧丽 郑玲 《系统仿真学报》 CAS CSCD 北大核心 2009年第15期4641-4646,共6页
Modelica语言是为解决复杂物理系统多领域统一建模与仿真问题而提出的一种面向对象基于方程的陈述式建模语言。它对DAE问题的表示已相对成熟,而对PDE问题的表示则相对缺乏。在多领域统一建模框架下,基于面向对象的思想,提出一种PDE与DA... Modelica语言是为解决复杂物理系统多领域统一建模与仿真问题而提出的一种面向对象基于方程的陈述式建模语言。它对DAE问题的表示已相对成熟,而对PDE问题的表示则相对缺乏。在多领域统一建模框架下,基于面向对象的思想,提出一种PDE与DAE问题一致的表示方法,实现对PDE问题的简单自然描述。然后使用直线法将PDE模型转化为DAE模型,并在Modelica仿真平台MWorks环境中进行求解,初步扩展了Modelica语言以支持三维PDE问题的建模与仿真。最后通过一个热传导PDE问题进行了验证。 展开更多
关键词 modelICA 三维PDE问题 建模与仿真 一致表示
原文传递
大语言模型幻觉检测方法综述
15
作者 李自拓 孙建彬 +5 位作者 陈广州 方馨悦 崔瑞靖 田植良 黄震 杨克巍 《计算机研究与发展》 北大核心 2026年第1期123-146,共24页
近年来,大语言模型(large language models,LLMs)在自然语言处理(natural language processing,NLP)等领域取得了显著进展,展现出强大的语言理解与生成能力。然而,在实际应用过程中,大语言模型仍然面临诸多挑战。其中,幻觉(hallucinati... 近年来,大语言模型(large language models,LLMs)在自然语言处理(natural language processing,NLP)等领域取得了显著进展,展现出强大的语言理解与生成能力。然而,在实际应用过程中,大语言模型仍然面临诸多挑战。其中,幻觉(hallucination)问题引起了学术界和工业界的广泛关注。如何有效检测大语言模型幻觉,成为确保其在文本生成等下游任务可靠、安全、可信应用的关键挑战。该研究着重对大语言模型幻觉检测方法进行综述:首先,介绍了大语言模型概念,进一步明确了幻觉的定义与分类,系统梳理了大语言模型从构建到部署应用全生命周期各环节的特点,并深入分析了幻觉的产生机制与诱因;其次,立足于实际应用需求,考虑到在不同任务场景下模型透明度的差异等因素,将幻觉检测方法划分为针对白盒模型和黑盒模型2类,并进行了重点梳理和深入对比;而后,分析总结了现阶段主流的幻觉检测基准,为后续开展幻觉检测奠定基础;最后,指出了大语言模型幻觉检测的各种潜在研究方法和新的挑战。 展开更多
关键词 幻觉检测 大语言模型 事实一致性 文本生成 自然语言处理
在线阅读 下载PDF
基于政策一致性指数模型的药品临床综合评价政策量化研究
16
作者 赵越 鞠晓宇 《中国药业》 2026年第1期19-25,共7页
目的探讨我国药品临床综合评价政策的优化思路。方法采用ROST CM 6软件对国务院及各部委2014年1月至2024年10月出台的21项药品临床综合评价相关政策文件进行文本挖掘,构建政策一致性(PMC)指数模型,并对其进行量化分析,计算PMC指数和PMC... 目的探讨我国药品临床综合评价政策的优化思路。方法采用ROST CM 6软件对国务院及各部委2014年1月至2024年10月出台的21项药品临床综合评价相关政策文件进行文本挖掘,构建政策一致性(PMC)指数模型,并对其进行量化分析,计算PMC指数和PMC凹陷指数,进行PMC曲面分析。结果21项政策文件评价结果中,仅有1项为优秀,2项为合格,其余均为良好;PMC指数均值为5.94,PMC凹陷指数均值为4.06,整体处于良好状态,但仍有提升空间。结论我国药品临床综合评价政策基本完善,建议加强各部委联合发文,畅通政策衔接;拓展政策内容中的评价对象,重视评价质量控制;强调评价结果服务于国家药物政策决策及对企业的反哺作用。 展开更多
关键词 政策一致性指数模型 政策量化 药品临床综合评价
暂未订购
CONSISTENCY OF LS ESTIMATOR IN SIMPLE LINEAR EV REGRESSION MODELS 被引量:13
17
作者 刘继学 陈希孺 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期50-58,共9页
Consistency of LS estimate of simple linear EV model is studied. It is shown that under some common assumptions of the model, both weak and strong consistency of the estimate are equivalent but it is not so for quadra... Consistency of LS estimate of simple linear EV model is studied. It is shown that under some common assumptions of the model, both weak and strong consistency of the estimate are equivalent but it is not so for quadratic-mean consistency. 展开更多
关键词 EV model CONSISTENCY
在线阅读 下载PDF
Modeling and Control of Time-pressure Dispensing for Semiconductor Manufacturing 被引量:5
18
作者 Cong-Ping Chen Han-Xiong Li Han Ding 《International Journal of Automation and computing》 EI 2007年第4期422-427,共6页
To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manufacturing, a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amo... To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manufacturing, a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amount dispensed in each cycle. Taking account of gas compressibility, an intelligent model-based control strategy is proposed to compensate the deviation of adhesive amount dispensed from the desired one. Both simulations and experiments show that the dispensing consistency is greatly improved by using the model-based control strategy developed in this paper. 展开更多
关键词 Time-pressure dispensing CONSISTENCY fluid flow rate model model-based control.
在线阅读 下载PDF
ASYMPTOTIC PROPERTIES OF ESTIMATORS IN PARTIALLY LINEAR SINGLE-INDEX MODEL FOR LONGITUDINAL DATA 被引量:3
19
作者 田萍 杨林 薛留根 《Acta Mathematica Scientia》 SCIE CSCD 2010年第3期677-687,共11页
In this article, a partially linear single-index model /or longitudinal data is investigated. The generalized penalized spline least squares estimates of the unknown parameters are suggested. All parameters can be est... In this article, a partially linear single-index model /or longitudinal data is investigated. The generalized penalized spline least squares estimates of the unknown parameters are suggested. All parameters can be estimated simultaneously by the proposed method while the feature of longitudinal data is considered. The existence, strong consistency and asymptotic normality of the estimators are proved under suitable conditions. A simulation study is conducted to investigate the finite sample performance of the proposed method. Our approach can also be used to study the pure single-index model for longitudinal data. 展开更多
关键词 Longitudinal data partially linear single-index model penalized spline strong consistency asymptotic normality
在线阅读 下载PDF
Model Checking-Based Testing of Web Applications 被引量:2
20
作者 ZENG Hongwei MIAO Huaikou 《Wuhan University Journal of Natural Sciences》 CAS 2007年第5期922-926,共5页
A formal model representing the navigation behavior of a Web application as the Kripke structure is proposed and an approach that applies model checking to test case generation is presented. The Object Relation Diagra... A formal model representing the navigation behavior of a Web application as the Kripke structure is proposed and an approach that applies model checking to test case generation is presented. The Object Relation Diagram as the object model is employed to describe the object structure of a Web application design and can be translated into the behavior model. A key problem of model checking-based test generation for a Web application is how to construct a set of trap properties that intend to cause the violations of model checking against the behavior model and output of counterexamples used to construct the test sequences. We give an algorithm that derives trap properties from the object model with respect to node and edge coverage criteria. 展开更多
关键词 Web application test generation model checking consistency relation
在线阅读 下载PDF
上一页 1 2 85 下一页 到第
使用帮助 返回顶部