检索结果-内蒙古大学图书馆

Energy budget of cold and hot gas-solid fluidized beds through CFD-DEM simulations

Particuology 2024年第6期89卷 153-171页

作者： Lei Bi Yunpeng Jiao Chunjiang Liu Jianhua Chen Wei Ge School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Direct energy budget is carried out for both cold and hot flow in gas–solid fluidization ***,the energy paths are proposed from thermodynamic *** consumption means total power input to the specific system,and it can be decomposed into energy retention and energy *** retention is the variation of accumulated mechanical energy in the system,and energy dissipation is the energy converted to heat by irreversible *** based on the Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)framework,different energy terms are quantified from the specific flow elements of fluid cells and particles as well as their interactions with the *** order to clarify the energy budget,it is important to identify which system is studied:the particle-fluid system or the particle *** the cold flow,the total energy consumption of the particle sub-system can well indicate the onset of bubbling and turbulent,while the variation of local energy consumption terms can reflect the evolution of heterogeneous *** the hot flow,different heat transfer mechanisms are analyzed and the solver is modified to reproduce the experimental *** impact of the heat transfer mechanisms and heat production on energy consumption is also *** proposed budget method has proven to be energy-conservative and easy to conduct,and it is hopeful to be applied to other multiphase flow systems.

关键词： Energy budget Gas-solid fluidization CFD-DEM Regime transition Heat transfer mechanism

来源：评论

学校读者我要写书评

暂无评论

Gas–solid reactor optimization based on EMMS-DPM simulation and machine learning

引用

Particuology 2024年第6期89卷 131-143页

作者： Haolei Zhang Aiqi Zhu Ji Xu Wei Ge State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Design,scaling-up,and optimization of industrial reactors mainly depend on step-by-step experiments and engineering experience,which is usually time-consuming,high cost,and high *** numerical simulation can reproduce high resolution details of hydrodynamics,thermal transfer,and reaction process in reactors,it is still challenging for industrial reactors due to huge computational *** this study,by combining the numerical simulation and artificial intelligence(AI)technology of machine learning(ML),a method is proposed to efficiently predict and optimize the performance of industrial reactors.A gas–solid fluidization reactor for the methanol to olefins process is taken as an example.1500 cases under different conditions are simulated by the coarse-grain discrete particle method based on the Energy-Minimization Multi-Scale model,and thus,the reactor performance data set is *** develop an efficient reactor performance prediction model influenced by multiple factors,the ML method is established including the ensemble learning strategy and automatic hyperparameter optimization technique,which has better performance than the methods based on the artificial neural ***,the operating conditions for highest yield of ethylene and propylene or lowest pressure drop are searched with the particle swarm optimization algorithm due to its strength to solve non-linear optimization *** show that decreasing the methanol inflow rate and increasing the catalyst inventory can maximize the yield,while decreasing methanol the inflow rate and reducing the catalyst inventory can minimize the pressure *** two objectives are thus conflicting,and the practical operations need to be compromised under different circumstance.

关键词： Discrete particle method Artificial intelligence Machine learning Particle swarm optimization Industrial reactor optimization

来源：评论

学校读者我要写书评

暂无评论

Fluidization thermal decomposition of sodium fluosilicate

引用

Chinese Journal of Chemical engineering 2023年第5期57卷 329-337页

作者： Feng Pan Sugang Ma Yu Ge Chuanlin Fan Qingshan Zhu State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China College of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

To break through the thermodynamic limitation that sodium fluosilicate only can be completely decomposed at high temperature,the technology of pre-decomposition under SiF_(4) atmosphere and deep decomposition under air condition at lower temperature was *** hydrolysis reaction of sodium fluosilicate can be effectively restrained when drying under vacuum or low *** decomposition results of sodium fluosilicate indicate that temperature has a very significant effect on its *** decomposition ratio can reach 79.4%at 600℃ for 1 h,and 99.6% at 700℃ for 1 h under air condition,*** velocity and the type of inert gas have no significant effect on its *** particles affect its decomposition performance due to agglomeration,while coarse particles have good thermal decomposition performance without significant *** decomposition reaction process in fluidized bed satisfies the classical Avrami Erofe'EV model,with the reaction order of 1.5 and the activation energy of 61.35 kJ·mol^(-1).

关键词： Sodium hexafluorosilicate Preparation Silicon tetrafluoride Absorption Fluidized bed

来源：评论

学校读者我要写书评

暂无评论

Fixed-time stabilization of discontinuous spatiotemporal neural networks with time-varying coefficients via aperiodically switching control

引用

Science China(Information Sciences) 2023年第5期66卷 182-195页

作者： Xiaofang HU Leimin WANG Chuan-Ke ZHANG Xiongbo WAN Yong HE School of Automation China University of Geosciences Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education

This paper focuses on the challenge of fixed-time control for spatiotemporal neural networks(SNNs) with discontinuous activations and time-varying coefficients. A novel fixed-time convergence lemma is proposed, which facilitates the handling of time-varying coefficients of SNNs and relaxes the restriction on the non-positive definiteness of the derivative of the Lyapunov function. Besides, a more flexible and economical aperiodically switching control technique is presented to stabilize SNNs within a fixed time,efectively reducing the amount of information transmission and control costs. Under the newly established fixed-time convergence lemma and aperiodically switching controller, many more general algebraic conditions are deduced to ensure the fixed-time stabilization of SNNs. Numerical examples are provided to manifest the validity of the results.

关键词： spatiotemporal neural networks discontinuous activations time-varying coefficients fixed-time stabilization aperiodically switching control

来源：评论

学校读者我要写书评

暂无评论

MindScore: quantifying human preference for text-to-image generation through multi-view lens

引用

Science China(Information Sciences) 2025年第6期68卷 72-85页

作者： Yiqi TONG Jiarui ZHANG Shaohang WEI Wei GUO Fuzhen ZHUANG Deqing WANG Xi YANG Richeng XUAN School of Artificial Intelligence Beihang University School of Computer Science and Engineering Beihang University Department of Computer Science and Engineering Shanghai Jiao Tong University School of Computer Science Peking University State Key Laboratory of Complex & Critical Software Environment Beihang University Beijing Academy of Artificial Intelligence

Understanding and quantifying the capabilities of foundation models, particularly in text-to-image(T2I) generation, is crucial for verifying their alignment with human expectations and practical requirements. However, evaluating T2I foundation models presents significant challenges due to the complex, multi-dimensional psychological factors that influence human preferences for generated images. In this work, we propose MindScore, a multi-view framework for assessing the generation capacity of T2I models through the lens of human preference. Specifically, MindScore decomposes the evaluation into four complementary modules that align with human cognitive processing of images: matching, faithfulness, quality,and realness. The matching module quantifies the semantic alignment between generated images and prompt text, while the faithfulness module measures how accurately the images reflect specific prompt details. Furthermore, we incorporate quality and realness modules to capture deeper psychological preferences, recognizing that unpleasant or distorted images often trigger adverse human responses. Extensive experiments on three T2I datasets with human preference annotations clearly validate the superiority of our proposed MindScore over various state-of-the-art baselines. Our case studies further reveal that MindScore offers valuable insights into T2I generation from a human-centric perspective.

关键词： text-to-image generation foundation models human preference evaluation multi-view assessment language and vision

来源：评论

学校读者我要写书评

暂无评论

A novel triple periodic minimal surface-like plate lattice and its data-driven optimization method for superior mechanical properties

引用

Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 217-238页

作者： Yanda WANG Yanping LIAN Zhidong WANG Chunpeng WANG Daining FANG State Key Laboratory for Turbulence and Complex Systems&Center for Applied Physics and Technology College of EngineeringPeking UniversityBeijing 100871China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China

Lattice structures can be designed to achieve unique mechanical properties and have attracted increasing attention for applications in high-end industrial equipment,along with the advances in additive manufacturing(AM)*** this work,a novel design of plate lattice structures described by a parametric model is proposed to enrich the design space of plate lattice structures with high connectivity suitable for AM *** parametric model takes the basic unit of the triple periodic minimal surface(TPMS)lattice as a skeleton and adopts a set of generation parameters to determine the plate lattice structure with different topologies,which takes the advantages of both plate lattices for superior specific mechanical properties and TPMS lattices for high connectivity,and therefore is referred to as a TPMS-like plate lattice(TLPL).Furthermore,a data-driven shape optimization method is proposed to optimize the TLPL structure for maximum mechanical properties with or without the isotropic *** this method,the genetic algorithm for the optimization is utilized for global search capability,and an artificial neural network(ANN)model for individual fitness estimation is integrated for high efficiency.A set of optimized TLPLs at different relative densities are experimentally validated by the selective laser melting(SLM)fabricated *** is confirmed that the optimized TLPLs could achieve elastic isotropy and have superior stiffness over other isotropic lattice structures.

关键词： lattice structure triple periodic minimal surface(TPMS) plate lattice structural optimization machine learning

来源：评论

学校读者我要写书评

暂无评论

Strain concentration factor of heterogeneous materials and analytical influence functions based on Eshelby tensor

引用

Theoretical & Applied Mechanics Letters 2024年第4期14卷 306-313页

作者： Shanqiao Huang Zifeng Yuan HEDPS Center for Applied Physics and TechnologyDepartment of Mechanics and Engineering SciencePeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing 100871China

In this manuscript,Eshelby tensor is employed to assess the strain concentration that arises in the matrix phase at the interface,offering precise values and locations of maximum strain under specific loading conditions for both spherical and cylindrical *** compared to numerical simulation results,the analytical predictions grounded in the Eshelby tensor exhibit satisfactory *** an analytical calculation method based on Eshelby tensor for the elastic strain influence functions of reduced-order homogenization(ROH)method is developed and adopted on particle-reinforced and fibrous composites,presenting its feasibility and advantage on off-line stage calculation of ROH *** error analyses between analytical and numerical results are *** numerical results also exhibit the necessity of finer interface partitioning to obtain the response on micro-scale with higher resolution.

关键词： Eshelby tensor Strain concentration Composite structures Reduced-order-homogenization Influence functions

来源：评论

学校读者我要写书评

暂无评论

Distinguishing Sensitive and Insensitive Options for the Winograd Schema Challenge 28th

Distinguishing Sensitive and Insensitive Options for the ...

引用

28th International Conference on Database systems for Advanced Applications, DASFAA 2023

作者： Li, Dong Wang, Pancheng He, Liangliang Pang, Kunyuan Li, Shasha Tang, Jintao Wang, Ting College of Computer Science and Technology National University of Defense Technology Changsha China Key Laboratory of Software Engineering for Complex Systems Changsha China

ISBN: (纸本)9783031306747

The Winograd Schema Challenge (WSC) is a popular benchmark for commonsense reasoning. Each WSC instance has a component that corresponds to the mention of the correct answer option of the two options in the context. We observe that the answers of many instances are insensitive to the options. In this paper, based on this observation, we propose an approach based on fine-tuning the pre-trained language model for WSC by distinguishing sensitive and insensitive options. First, we split WSC instances into option-sensitive and insensitive categories, and use option expanding and option masking strategies to weaken the options so that the model does not pay attention to options when they are insensitive during fine-tuning. Second, we treat the two categories as intermediate-task of each other, and use transfer learning to improve the performance. We fine-tune BERT-Large and T5-XXL with our approach on WINOGRANDE, a new dataset of WSC, and the experiment shows our method outperforms baselines by a large margin, achieving state-of-the-art, which indicates the effectiveness of our instance-distinguishing strategy. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Large dataset

来源：评论

学校读者我要写书评

暂无评论

Theoretical study on the stability of nanobubbles and its verification in molecular dynamics simulation

引用

Particuology 2024年第4期87卷 99-105页

作者： Sheng Mi Chaofeng Hou Wei Ge School of Chemical Engineering and Technology Tianjin UniversityTianjin300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing.100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

The stability of vapor nanobubbles in bulk liquid was investigated theoretically and the critical bubble size was derived from macroscale thermodynamic equations,below which the system destabilizes with sharp drop in *** critical size was quantitatively verified in molecular dynamic simulation using the Lennard-Jones model of argon,where stronger attraction between the molecules at lower density is found to contribute most to the drop of system pressure and,as the Laplace pressure on the curved bubble interface fails to balance the pressure difference across the interface,the bubbles become *** theoretical model could be extended to other systems where reliable equations of state and interfacial tension are available.

关键词： Nanobubble Stability Phase diagram Critical size

来源：评论

学校读者我要写书评

暂无评论

3D Measurement of complex Textured Objects Based on Bidirectional Fringe Projection 39

3D Measurement of Complex Textured Objects Based on Bidirect...

引用

39th Annual AAAI Conference on Artificial Intelligence, AAAI 2025

作者： Chen, Yuchong Yu, Jian Gai, Shaoyan Cai, Zeyu Da, Feipeng School of Automation Southeast University MoE Key Laboratory of Measurement and Control of Complex Systems of Engineering Southeast University China

ISBN: (纸本)157735897X

In structured light systems, the accuracy of measurement notably diminishes when assessing complex texture objects, especially encountering boundaries between various colors. To address this challenge, this paper meticulously analyzes and establishes an error model, elaborating the correlation between phase errors and the gradients of phase and grayscale. Based on this analysis, a novel high-precision method is proposed for measuring complex texture objects via bidirectional fringe projection. This approach firstly leverages horizontal and vertical fringe projections to derive bidirectional phase information and calculates the angles between the tangent of the texture edges and the phase gradient. Subsequently, a refined temporal phase correction algorithm is formulated based on the epipolar matching algorithm and the devised error model, effectively reducing errors caused by complex textures. Ultimately, corrected point clouds are calculated based on bidirectional phases, and the obtained point clouds are merged to further diminish phase errors. Comparison experiments indicate that this method can reduce Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) by 65.74% and 67.75%, respectively. Compared to existing methods, it improves performance by 27.29% and 33.74%, respectively, demonstrating superior performance. Copyright © 2025, Association for the Advancement of Artificial Intelligence (***). All rights reserved.

关键词： Mean square error

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：