检索结果-内蒙古大学图书馆

Electrochemical CO_(2) reduction with ionic liquids: review and evaluation

学校读者我要写书评

暂无评论

Industrial Chemistry & Materials

Industrial Chemistry & Materials 2023年第3期1卷 410-430页

作者： Yangshuo Li Fangfang Li Aatto Laaksonen Chuan Wang Paul Cobden Per Boden Yanrong Liu Xiangping Zhang Xiaoyan Ji Energy Engineering Division of Energy ScienceLulea University of TechnologyLuleå97187Sweden Department of Materials and Environmental Chemistry Arrhenius LaboratoryStockholm University10691 StockholmSweden Centre of Advanced Research in Bionanoconjugates and Biopolymers Petru Poni Institute of Macromolecular ChemistryAleea Grigore Ghica-Voda41A700487 IasiRomania State Key Laboratory of Materials-Oriented and Chemical Engineering Nanjing Tech UniversityNanjing210009P.R.China University of Cagliari Department of Chemical and Geological SciencesCampus MonserratoSS 554 bivio per Sestu09042MonserratoItaly Metallurgy Department Swerim AB97125LuleåSweden SMA Mineral AB 68227FilipstadSweden CAS Key Laboratory of Green Process and Engineering Beijing Key Laboratory of Ionic Liquids Clean ProcessState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

The increasing CO_(2) emission,as the chief culprit causing numerous environmental problems,could be addressed by the electrochemical CO_(2) reduction(CO_(2)R)to the added-value carbon-based *** liquids(ILs)as electrolytes and co-catalysts have been widely studied to promote CO_(2)R owing to their unique *** the potential products of CO_(2)R,those only containing one carbon atom,named C1 products,including CO,CH_(3)OH,CH_(4),and syngas,are easier to achieve than *** this study,we first summarized the research status on CO_(2)R to these C1 products,and then,the state-of-theart experimental results were used to evaluate the economic potential and environmental *** the rapid development in CO_(2)R,future scenarios with better CO_(2)R performances were reasonably assumed to predict the future business for each *** the studied C1 products,the research focuses on CO,where satisfactory results have been *** evaluation shows that producing CO via CO_(2)R is the only profitable route at ***3OH and syngas of H2/CO(1:1)as the targeted products can become profitable in the foreseen *** addition,the life cycle assessment(LCA)was used to evaluate the environmental impact,showing that CO_(2)R to CH4 is the most environmentally friendly pathway,followed by the syngas of H_(2)/CO(2:1)and CO,and the further improvement of the CO_(2)R performance can make all the studied C1 products more environmentally ***,CO is the most promising product from both economic and environmental impact aspects.

关键词： Electrochemical-CO_(2)-reduction Ionic-liquids C1-product Economic-evaluation Environmental-impact

Fluctuation properties of the eigenfrequencies and scattering matrix of closed and open unidirectional graphs with chaotic wave dynamics

学校读者我要写书评

暂无评论

Physical Review E 2022年第1期106卷 014211-014211页

作者： Jiongning Che Xiaodong Zhang Weihua Zhang Barbara Dietz Guozhi Chai Lanzhou Center for Theoretical Physics and the Gansu Provincial Key Laboratory of Theoretical Physics Lanzhou University Lanzhou Gansu 730000 China Center for Theoretical Physics of Complex Systems Institute for Basic Science (IBS) Daejeon 34126 Korea School of Physical Science and Technology and Key Laboratory for Magnetism and Magnetic Materials of MOE Lanzhou University Lanzhou Gansu 730000 China

We present experimental and numerical results for the fluctuation properties in the eigenfrequency spectra and of the scattering matrix of closed and open unidirectional quantum graphs, respectively. Unidirectional quantum graphs, that are composed of bonds connected by reflectionless vertices, were introduced by Akila and Gutkin [Akila and Gutkin, J. Phys. A: Math. Theor. 48, 345101 (2015)]. The nearest-neighbor spacing distribution of their eigenvalues was shown to comply with random-matrix theory predictions for typical chaotic systems with completely violated time-reversal invariance. The occurrence of short periodic orbits confined to a fraction of the system, that lead in conventional quantum graphs to deviations of the long-range spectral correlations from the behavior expected for typical chaotic systems, is suppressed in unidirectional ones. Therefore, we pose the question whether such graphs may serve as a more appropriate model for closed and open chaotic systems with violated time-reversal invariance than conventional ones. We compare the fluctuation properties of their eigenvalues and scattering matrix elements and observe especially in the long-range correlations larger deviations from random-matrix theory predictions for the unidirectional graphs. These are attributed to a loss of complexity of the underlying dynamic, induced by the unidirectionality.

关键词： Quantum chaos Wave chaos

Turbulence Model Development based on a Novel Method Combining Gene Expression Programming with an Artificial Neural Network

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Li, Haochen Waschkowski, Fabian Zhao, Yaomin Sandberg, Richard D. HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China Joint Laboratory of Marine Hydrodynamics and Ocean Engineering Pilot National Laboratory for Marine Science and Technology Shandong Qingdao266237 China State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing100871 China Department of Mechanical Engineering University of Melbourne VIC3010 Australia

Data-driven methods are widely used to develop physical models, but there still exist limitations that affect their performance, generalizability and robustness. By combining gene expression programming (GEP) with artificial neural network (ANN), we propose a novel method for symbolic regression called the gene expression programming neural network (GEPNN). In this method, candidate expressions generated by evolutionary algorithms are transformed between the GEP and ANN structures during training iterations, and efficient and robust convergence to accurate models is achieved by combining the GEP’s global searching and the ANN’s gradient optimization capabilities. In addition, sparsity-enhancing strategies have been introduced to GEPNN to improve the interpretability of the trained models. The GEPNN method has been tested for finding different physical laws, showing improved convergence to models with precise coefficients. Furthermore, for large-eddy simulation of turbulence, the subgrid-scale stress model trained by GEPNN significantly improves the prediction of turbulence statistics and flow structures over traditional models, showing advantages compared to the existing GEP and ANN methods in both a priori and a posteriori tests. Copyright © 2023, The Authors. All rights reserved.

关键词： Neural networks

A Novel Vector-Field-Based Motion Planning Algorithm for 3D Nonholonomic Robots

学校读者我要写书评

暂无评论

arXiv 2023年

作者： He, Xiaodong Yao, Weijia Sun, Zhiyong Li, Zhongkui The State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science College of Engineering Peking University Beijing100871 China University of Groningen Groningen9747 AG Netherlands The Department of Electrical Engineering Eindhoven University of Technology Eindhoven5612 AZ Netherlands

This paper focuses on the motion planning for mobile robots in 3D, which are modelled by 6-DOF rigid body systems with nonholonomic kinematics constraints. We not only specify the target position, but also bring in the requirement of the heading direction at the terminal time, which gives rise to a new and more challenging 3D motion planning problem. The proposed planning algorithm involves a novel velocity vector field (VF) over the workspace, and by following the VF, the robot can be navigated to the destination with the specified heading direction. In order to circumvent potential collisions with obstacles and other robots, a composite VF is designed by composing the navigation VF and an additional VF tangential to the boundary of the dangerous area. Moreover, we propose a priority-based algorithm to deal with the motion coupling issue among multiple robots. Finally, numerical simulations are conducted to verify the theoretical results. Copyright © 2023, The Authors. All rights reserved.

关键词： Motion planning

Hierarchical Safe Control of Multiagent systems With Malicious Attacks Using Adaptive Fault-Tolerant Consensus Control

学校读者我要写书评

暂无评论

IEEE Transactions on Aerospace and Electronic systems 2025年

作者： Zhang, Pu Zhang, Kun Huang, Yulong Ni, Junkang Lv, Yuezu Gong, Xin Duan, Haibin Xi'an University of Technology School of Automation and Information Engineering Xi'an710048 China Beihang University School of Astronautics Beijing100191 China Harbin Engineering University College of Intelligent Systems Science and Engineering Harbin150001 China Northwestern Polytechnical University School of Automation Xi'an710072 China Beijing Institute of Technology MIIT Key Laboratory of Complex-field Intelligent Sensing Beijing100081 China Southeast University School of Cyber Science and Engineering Nanjing211189 China Beihang University School of Automation Science and Electrical Engineering Beijing100083 China

This paper proposed a hierarchical control framework that integrates an upper observer layer and a lower tracking layer. Based on higher-order sliding mode observer in the upper layer, a distributed high-order sliding mode observer (SMO) is used to approximate the leader's state, which can also identify some unknown and uncertain terms caused by malicious attacks. For the lower tracking layer, an adaptive fixed-time prescribed performance fault-tolerant control (FTPPFTC) method is leveraged to address the problem of malicious attacks and help the following agent achieve the stable tracking performance. By using the developed method, it is proved that the tracking errors of the multi-agent systems can converge into a small neighborhood within the fixed time. Finally, the numerical examples and comparative results illustrate the effectiveness of the proposed control method. © 1965-2011 IEEE.

关键词： Sliding mode control

Screening of metal-modified biochars for practical phosphorus recovery

学校读者我要写书评

暂无评论

science of the Total Environment 2024年 956卷 177342页

作者： Li, Man Xie, Qian Xu, Fangxi Zhang, Yan Zhuang, Zechao Xu, Jiawei Xiang, Hai Li, Yongfu Cai, Yanjiang Chen, Zuliang Yu, Bing State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Hangzhou311300 China Zhejiang A&F University Hangzhou311300 China Zhejiang Taizhou Ecological and Environmental Monitoring Center Taizhou318000 China Department of Chemistry Tsinghua University Beijing100084 China Jiangsu Key Laboratory of Numerical Simulation of Large Scale Complex Systems and School of Chemistry and Materials Science Nanjing Normal University Nanjing210023 China Fujian Key Laboratory of Pollution Control and Resource Reuse School of Environmental and Resource Sciences Fujian Normal University Fujian Province Fuzhou350007 China

The utilization of metal-modified biochars (MBCs) for practical phosphorus recovery has attracted significant research interest recently. However, the optimal choice of metals and modification methods for MBCs remains unclear. This study addresses this gap by comparing the phosphate adsorption capabilities of various MBCs using real municipal wastewater. The results show that zinc-modified biochar exhibits superior phosphate adsorption compared to biochars modified with calcium, magnesium, aluminum, and iron. Specifically, zinc-modified biochar prepared through metal-mediated biomass pyrolysis with alkaline soaking (ZnBC-OH) demonstrates the highest adsorption capacity, achieving 36.6 mg P/g in wastewater with a phosphate concentration of 5 mg P/L. This performance surpasses that of previously reported non-lanthanide modified biochars and is comparable to lanthanide-modified biochars. Mechanistic investigations reveal that the exceptional performance of ZnBC-OH is due to the presence of highly dispersed ZnO sites, which facilitate the formation of Zn3(PO4)2·4H2O precipitation, effectively retaining phosphate. Furthermore, a techno-economic analysis indicates that using ZnBC-OH in a fixed-bed column system can reduce phosphate levels from 6 mg L−1 to below 0.5 mg L−1 at a cost of 1.834 USD per ton of secondary treated wastewater, underscoring its promising application potential. © 2024 Elsevier B.V.

关键词： Wastewater treatment

GeoDTR+: Toward Generic Cross-View Geolocalization via Geometric Disentanglement

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Zhang, Xiaohan Li, Xingyu Sultani, Waqas Chen, Chen Wshah, Safwan Department of Computer Science and Vermont Complex Systems Center University of Vermont Burlington United States Lin Gang Laboratory Shanghai China Intelligent Machine Lab Information Technology University Pakistan Center for Research in Computer Vision University of Central Florida United States

Cross-View Geo-Localization (CVGL) estimates the location of a ground image by matching it to a geo-tagged aerial image in a database. Recent works achieve outstanding progress on CVGL benchmarks. However, existing methods still suffer from poor performance in cross-area evaluation, in which the training and testing data are captured from completely distinct areas. We attribute this deficiency to the lack of ability to extract the geometric layout of visual features and models' overfitting to low-level details. Our preliminary work [1] introduced a Geometric Layout Extractor (GLE) to capture the geometric layout from input features. However, the previous GLE does not fully exploit information in the input feature. In this work, we propose GeoDTR+ with an enhanced GLE module that better models the correlations among visual features. To fully explore the LS techniques from our preliminary work, we further propose Contrastive Hard Samples Generation (CHSG) to facilitate model training. Extensive experiments show that GeoDTR+ achieves state-of-the-art (SOTA) results in cross-area evaluation on CVUSA [2], CVACT [3], and VIGOR [4] by a large margin (16.44%, 22.71%, and 13.66% without polar transformation) while keeping the same-area performance comparable to existing SOTA. Moreover, we provide detailed analyses of GeoDTR+. Our code will be available at https://***/vail-uvm/geodtr_plus. Copyright © 2023, The Authors. All rights reserved.

关键词： Antenna grounds

Interior derivative estimates and Bernstein theorem for Hessian quotient equations

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Dai, Limei Bao, Jiguang Wang, Bo School of Mathematics and Information Science Weifang University Weifang261061 China School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing100875 China School of Mathematics and Statistics Beijing Institute of Technology Beijing100081 China

In this paper, we obtain the interior derivative estimates of solutions for elliptic and parabolic Hessian quotient equations. Then we establish the Bernstein theorem for parabolic Hessian quotient equations, that is, any parabolically convex solution (Equation presented) in n × (−∞, 0] must be the form of (Equation presented) with m > 0 being a constant and P being a convex quadratic polynomial. Copyright © 2023, The Authors. All rights reserved.

关键词： Polynomials

Word-level BERT-CNN-RNN Model for Chinese Punctuation Restoration 6

学校读者我要写书评

暂无评论

Word-level BERT-CNN-RNN Model for Chinese Punctuation Restor...

6th IEEE International Conference on Computer and Communications, ICCC 2020

作者： Zhang, Zhe Liu, Jie Chi, Lihua Chen, Xinhai Science and Technology on Parallel and Distributed Processing Laboratory Laboratory of Software Engineering for Complex Systems National University of Defense Technology Changsha China College of Computer Science and Electronic Engineering Hunan University Changsha China

ISBN: (纸本)9781728186351

Punctuation restoration in speech recognition has a wide range of application scenarios. Despite the widespread success of neural networks methods at performing punctuation restoration for English, there have been only limited attempts for Chinese punctuation restoration. Due to the differences between Chinese and English in terms of grammar and basic semantic units, existing methods for English is not suitable for Chinese punctuation restoration. To tackle this problem, we propose a hybrid model combining the kernel of Bidirectional Encoder Representations from Transformers (BERT), Convolution Neural Network (CNN) and Recurrent Neural Network (RNN). This model employs a flexible structure and special CNN design which can extract word-level features for Chinese language. We compared the performance of the hybrid model with five widely-used punctuation restoration models on the public dataset. Experimental results demonstrate that our hybrid model is simple and efficient. It outperforms other models and achieves an accuracy of 69.1%. © 2020 IEEE.

关键词： Recurrent neural networks