检索结果-内蒙古大学图书馆

Enhancement of weathered crust elution-deposited rare earth ores leaching process with PQ-10 addition

Journal of Rare Earths 2025年第1期43卷 180-190,I0007页

作者： Aoyang Sha Huifang Yang Zhengyan He Zhigao Xu Chenjie Wu Ming Wu Ru'an Chi Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission&Hubei Key Laboratory of Catalysis and Materials ScienceCollege of Resources and Environmental ScienceSouth-Central Minzu UniversityWuhan430074China Key Laboratory for Green Chemical Process of Ministry of Education School of Resources&Safety EngineeringWuhan Institute of TechnologyWuhan 430073China

To solve the problems of the long development period,low mass transfer efficiency and high impurity conte nt in the in-situ leaching process of weathe red crust elution-deposited rare earth ores(WCE-DREO),cationic hydroxyethyl cellulose(PQ-10)was composited with conventional leaching agent ammonium sulfate((NH_(4))_(2)SO_(4))to form a novel composite leaching *** effects of PQ-10 concentration,leaching temperature and leaching flow rate of the composite leaching agent on the leaching kinetics and mass transfer processes of rare earth(RE)and aluminum(Al)were *** to the single leaching agent(NH_(4))_(2)SO_(4),the composite leaching agent(2 wt%(NH_(4))_(2)SO_(4)+0.02 wt%PQ-10)can reduce the RE leaching equilibrium time from 465 to 130 min and increase the RE leaching efficiency and decrease the Al leaching *** also facilitates the leaching process of WCE-DREO by increasing the peak concentrations of RE and Al,reducing the theoretical tower plate height(HETP)and improving the leaching mass transfer *** is indicated that PQ-10 can promote the leaching of *** leaching process of the composite leaching system conforms to the diffusion kinetic control *** the PQ-10 concentration is in the range of 0.005 wt%-0.020 wt%,the reaction orders of RE and Al are 0.73 and 0.54,respectively,which shows a positive effect on the leaching velocity;when the PQ-10 concentration is in the range of 0.030 wt%-0.060 wt%,the reaction orders of RE and Al are-1.16 and-0.75,respectively,which show a negative effect on the leaching *** the range of 10-50℃,the apparent activation energies of RE and Al are 15.02 and 17.31 kJ/mol,respectively,and the higher the leaching temperature,the smaller the HETP and the higher the leaching velocity and mass transfer *** increase in leaching flow rate contributes to the increase in the longitudinal diffusion velocity of the leaching agent within WCE-DREO,causing a shorter time for RE

关键词： Cationic hydroxyethyl cellulose Weathered crust elution-deposited rare earthores Leaching Novel compositeagent

来源：评论

学校读者我要写书评

暂无评论

Machine learning driven rational design of dual atom catalysts on graphene for carbon dioxide electroreduction

引用

Nano Research 2025年第1期18卷 186-194页

作者： Dongxu Jiao Xinyi Li Mingzi Sun Lin Liu Jinchang Fan Jingxiang Zhao Bolong Huang Xiaoqiang Cui State Key Laboratory of Automotive Simulation and Control School of Materials Science and Engineeringand Key Laboratory of Automobile Materials of MOEJilin UniversityChangchun 130012China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina College of Chemistry and Chemical Engineering and Key Laboratory of Photonic and Electronic Bandgap MaterialsMinistry of EducationHarbin Normal UniversityHarbin 150025China

The development of high-performance atomiccatalysts for the carbon dioxide reduction reaction(CO_(2)RR)is atime-consuming process due to the complexity of the reactionmechanism and the uncertainty of the active ***,wehave proposed combining density functional theory(DFT)andmachine learning(ML)to investigate the potential of topologicalgraphene-based dual-atom catalysts(DACs)as CO_(2)*** analyzing the ML results,we identify thenumber of d-orbital electrons in the active site as a key factorinfluencing the CO_(2)RR catalytic ***,wepropose a simple descriptor to measure the CO_(2)RR activity ofthese *** findings provide plausible explanations for thesynergistic interactions between bimetallic atoms in CO_(2)RR andallow us to screen the homogeneous Ni-Ni pair as the mostpromising dual-atom *** work offers a fast MLapproach based on limited DFT calculations to predict the mostelectroactive and stable DACs on carbon support for CO_(2)RR,facilitating rapid screening of high-performance dual-atomcatalysts.

关键词： CO_(2)reaction reduction dual-atom catalysts density functional theory machine learning

来源：评论

学校读者我要写书评

暂无评论

Surpassing the differential synthetic wavelength of dual-wavelength digital holography by optimizing the search for an unwrapping coefficient

引用

Optics Letters 2025年第9期50卷 2990-2993页

作者： Shan, Mingguang Jia, Yuanyuan Ding, Zhenhua Zhong, Zhi Yu, Lei Liu, Bin Wang, Lijing Liu, Lei College of Information and Communication Engineering Harbin Engineering University Heilongjiang Harbin150001 China Key Laboratory of Advanced Marine Communication and Information Technology Ministry of Industry and Information Technology Harbin Engineering University Heilongjiang Harbin150001 China

The measurement range of dual-wavelength digital holography (DWDH) is always limited by differential synthetic wavelength (DSW) with low signal-to-noise ratio (SNR), which limits the application of DWDH. In this paper, we propose a novel, to the best of our knowledge, algorithm to surpass DSW of DWDH by optimizing the search for an unwrapping coefficient. The measured phase of the 1st wavelength can be unwrapped by its unwrapping coefficient and used to induce a wrapped phase of the 2nd wavelength. Owing to the explicit relationship between two measured phase maps of the same sample in DWDH, the induced wrapped phase from the 1st wavelength should be equal to the measured phase of the 2nd wavelength. Therefore, by minimizing the difference between the measured and the induced phase maps of the 2nd wavelength, the unwrapping coefficient of the 1st wavelength can be retrieved, and the unwrapped phase with an extended measurement range can be reconstructed correctly. This approach aims to overcome the limitations of measurement range and low SNR by DSW, to enable high-efficiency and broad-range measurement. This advancement significantly enhances the prospect of the practical application of DWDH. The feasibility and efficiency of this approach would be validated through numerical simulations and practical experiments. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Digital holography Numerical simulation Phase Phase measurement Phase noise Refractive index

来源：评论

学校读者我要写书评

暂无评论

Spatiotemporal distribution patterns of macrobenthic communities and their relationship with environmental factors in the Shengsi Archipelago(Zhejiang,China)

引用

Acta Oceanologica Sinica 2025年第1期44卷 113-126,I0001-I0011页

作者： Lingxiang Jin Yibo Liao Peisong Yu Yanbin Tang Qinghe Liu Rongliang Zhang Lu Shou Jiangning Zeng Quanzhen Chen Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Key Laboratory of Ocean Space Resource Management Technology Ministry of Natural ResourcesHangzhou 310012China Laboratory of Nearshore Engineering Environment and Ecological Security of Zhejiang Province Hangzhou 310012China

Macrobenthic organisms are commonly employed as biomonitors for environmental risk *** this study,we aimed to investigate the spatial and temporal patterns of the macrobenthic community,which is influenced by environmental factors of sediments and bottom water *** sampled a total of 12,11,10,and 11 stations in the Shengsi Archipelago during June 2010,August 2010,November 2020,and April 2021 respectively.A total of 124 species of macrobenthos were identified,with polychaetes being the dominant *** abundance,biomass,and diversity indices exhibited no significant temporal ***,biodiversity did not exhibit a clear spatial gradient,likely due to the small study area and the absence of significant differences in key factors such as ***,the stations with the lowest biodiversity values consistently appeared in the southwest region,possibly due to the impact of human *** differences in the macrobenthic community were observed between all months except between June and August,and mollusk Endopleura lubrica and polychaete Sigambra hanaokai were important contributors to these differences according to the results of the Similarity Percentages *** particulate matter(SPM)was identified as the primary driving factors of macrobenthic *** summary,the community structure underwent temporal changes influenced by complex current patterns,while biodiversity remained relatively *** study contributes to our understanding of the key environmental factors affecting macrobenthic communities and *** also provides valuable data support for the long-term monitoring of macrobenthos and the environment in the Shengsi Archipelago.

关键词： macrobenthic community Shengsi Archipelago distribution pattern biodiversity environmental factors

来源：评论

学校读者我要写书评

暂无评论

High-Sensitivity and External RI-Independent Mode-Selective Michelson Interferometer Using a Single-Ended Helical Graded-Index Fiber

引用

Journal of Lightwave technology 2025年第11期43卷 5336-5344页

作者： Zhu, Chengliang Meng, Xinyue Shi, Mengshuo Cheng, Tonglei Zhao, Yong Northeastern University College of Information Science and Engineering Shenyang110004 China Northeastern University School of Control Engineering Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao066004 China State Key Laboratory of Synthetical Automation for Process Industries Shenyang China Northeastern University School of Control Engineering Qinhuangdao066004 China

We have theoretically and experimentally proposed and demonstrated an all-in-fiber-core mode-selective Michelson interferometer (MS-MI) sensor utilizing a single-ended helical graded-index few-mode fiber (SE-HGIFMF). The SE-HGIFMF effectively eliminates multi-mode interference, remains insensitive to external refractive index (RI) variations, and significantly enhances sensing sensitivity due to the minimal disparity in group RI between the two guided core modes. We investigated the torsion, strain, and temperature characteristics of the sensor, achieving sensitivities of 1.785 nm/(rad/m) for directional torsion, 0.0316 nm/μϵ for strain, and 0.624 nm/°C for temperature. These sensitivities are competitive within the fiber optic sensor family and represent the highest values reported for mode-selective MI and Mach-Zehnder interferometer (MZI) sensors to our knowledge. The proposed sensor not only demonstrates exceptional sensitivity but also offers directionality identification for torsion, ease of use, flexible installation, low loss, and high reliability, showcasing robustness against environmental fluctuations. © 1983-2012 IEEE.

关键词： Michelson interferometers

来源：评论

学校读者我要写书评

暂无评论

Optimal Adaptive Parameter Estimation With Online Varying Learning Gain

引用

IEEE Transactions on Automatic control 2025年第5期70卷 3518-3525页

作者： Chen, Siyu Na, Jing Huang, Yingbo Xing, Yashan Zhao, Jing Wong, Pak Kin Kunming University of Science and Technology Faculty of Mechanical and Electrical Engineering Yunnan Key Laboratory of Intelligent Control and Application Kunming650500 China University of Macau Department of Electromechanical Engineering 999078 China

It has been well known that the learning gain plays a crucial role in the adaptive parameter estimation (APE) for guaranteeing fast convergence and robustness. However, the tuning of learning gains in the existing methods is generally empirical and time-consuming. To address this issue, this article presents a novel APE approach to explore the optimality principle in the design of adaptive laws to obtain an online updated optimal learning gain, which is derived to minimize a cost function of estimation error with two weighting matrices. For this purpose, the estimation error is first reconstructed by using filter operations on the system and introducing several auxiliary variables. Then, two constructive APE algorithms driven by the extracted estimation error are developed. Finally, inspired by the duality of control and estimation, the estimation error dynamics are reformulated as a closed-loop system with an analogous control action to minimize the cost function. By using the Hamiltonian function, a differential Riccati equation is derived to find an optimal solution of learning gain to construct an optimal adaptive law. The robustness of the proposed adaptive laws subjected to disturbances is also analyzed. Comparative numerical simulations are given to illustrate the superiority of the proposed method. © 1963-2012 IEEE.

关键词： Cost functions

来源：评论

学校读者我要写书评

暂无评论

Spatial and Temporal Distribution of Metal Elements in the Rivers of Northern Jiangsu Province

引用

Journal of Ocean University of China 2025年第1期24卷 157-168页

作者： YUAN Liping LIU Qian JIAN Huimin MI Tiezhu YANG Fuxia YAO Qingzhen Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of EducationOcean University of ChinaQingdao 266100China Laboratory of Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Land and Sea Ecological Governance and Systematic Regulation of the Ministry of Ecology and Environment Shandong Academy for Environmental PlanningJinan 250101China

The concentrations of V,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Mo,Cd,and Pb were determined in Doulonggang River,Xinyanggang River,Huangshagang River,Sheyanghe River,Guangaizongqu River,and Linhonghe River at the North of Jiangsu Province in *** annual average concentrations of V,Cr,Mn,Fe,Co,Ni,Cu,Zn,As,Mo,Cd and Pb in the six rivers were 2.20,1.22,4.53,21.9,0.13,2.79,1.77,4.00,2.97,3.87,0.01,0.19μg L^(-1)*** highest concentration of most trace metals were found in Guangaizongqu River and Linhonghe River,and the lowest concentration were found in Xinyanggang River and Huangshagang *** principal component analysis(PCA)resulted of two factors together explained 91.2%of the variance with>1initial eigenvalue,indicating that both natural and anthropogenic activities were contributing factors as the source of metal abundance in rivers of northern Jiangsu *** first major component represented the influence of anthropogenic activities,including industry and agriculture,with a contribution rate of 54.1%,affected Cr,Fe,Cu,Zn,Mo,Cd and *** second(such as V,Mn,Co,Ni,As)was a mixed source,including the natural processes such as precipitation,erosion and weathering and anthropogenic action like industry and agriculture,with a contribution rate of 37.1%.Seasonal variations in trace metal concentrations were influenced by temperature,salinity,water discharge,and input of external *** highest concentrations were found in wet season and were strongly influenced by rainfall and seasonal industrial and agricultural activities.

关键词： trace metal distribution rivers northern Jiangsu Province

来源：评论

学校读者我要写书评

暂无评论

Non-uniform electron density estimation based on electromagnetic wave attenuation in plasma

引用

Chinese Physics B 2025年第1期34卷 381-386页

作者： Zhaoying Wang Lixin Guo Maixia Fu Shaoshuai Guo Yinsheng Li Key Laboratory of Grain Information Processing and Control(Henan University of Technology) Ministry of EducationZhengzhou 450001China College of Information Science and Engineering Henan University of TechnologyZhengzhou 450001China School of Physics Xidian UniversityXi’an 710071China

The surface of a high-speed vehicle reentering the atmosphere is surrounded by plasma *** to the influence of the inhomogeneous flow field around the vehicle,understanding the electromagnetic properties of the plasma sheath can be *** the electron density of the plasma sheath is crucial for understanding and achieving plasma stealth of *** this work,the relationship between electromagnetic wave attenuation and electron density is deduced *** attenuation distribution along the propagation path is found to be proportional to the integral of the plasma electron *** result is used to predict the electron density ***,the average electron density is obtained using a back-propagation neural network ***,the spatial distribution of the electron density can be determined from the average electron density and the normalized derivative of attenuation with respect to the propagation *** to traditional probe measurement methods,the proposed approach not only improves efficiency but also preserves the integrity of the plasma environment.

关键词： attenuation electromagnetic propagation plasma electron density

来源：评论

学校读者我要写书评

暂无评论

A Lyapunov-Based Framework for Trajectory Planning of Wheeled Vehicle Using Imitation Learning

引用

IEEE Transactions on Automation Science and engineering 2025年 22卷 12118-12133页

作者： Lai, Jialun Wu, Zongze Ren, Zhigang Chen, Ci Tan, Qi Xie, Shengli Guangdong University of Technology School of Automation Guangdong Guangzhou510006 China Shenzhen University College of Mechatronics and Control Engineering Guangdong Shenzhen518052 China Zhejiang University State Key Laboratory of Industrial Control Technology Hangzhou310027 China

Trajectory planning with a learning-based approach has emerged as a crucial element in autonomous unmanned systems and has attracted substantial interest from both academia and industry. However, unresolved issues persist concerning data efficiency, safety, convergence, and generalization within the control pipeline. To address this gap, this work presents a trajectory planning method that combines the differential flatness of wheeled vehicle with global convergence property. Our proposed framework transforms the trajectory planning problem, integrating kinematic constraints into a motion planning paradigm. This transformation significantly reduces the state space associated with trajectory planning. Initially, Gaussian mixture regression (GMR) is employed to learn the nonlinear mapping from flat input, leveraging a limited number of demonstrations solved by the optimal control method. Subsequently, we design an asymmetric quadratic Lyapunov function that incorporates both random barrier information and the potential convergence property of the demonstration trajectories. Based on the optimized parameterized Lyapunov function incorporating the convergence and safety criteria, the analytical supplementary control is subsequently obtained by solving a quadratic programming problem to compensate for the prediction errors of GMR, which make the framework complete. Both numerical and real-world experiments are performed to validate the effectiveness of our framework. © 2004-2012 IEEE.

关键词： Motion planning

来源：评论

学校读者我要写书评

暂无评论

A review of motion planning for redundant space manipulators

引用

Science China(Technological Sciences) 2025年第3期68卷 30-53页

作者： Ziqiang ZHANG Xiaoshuo LIU Meng NING Xiaohui LI Weihui LIU Ye LU College of Mechanical and Energy Engineering Beijing University of TechnologyBeijing100124China School of Mechanical Engineering Jiangnan UniversityWuxi214122China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing100094China Department of Civil Engineering Monash UniversityMelbourne3800Australia

Redundant space manipulators(RSM)exhibit high flexibility and can assist astronauts in completing various onorbit service(OOS)tasks,which have been applied to the International Space Station(ISS)and China Space Station(CSS).Motion planning stands as a fundamental technology within RSM,guiding the manipulator to reach designated positions smoothly and execute operational tasks with optimal ***,the intricate nature of the space environment presents challenges to the motion planning of *** this paper,in response to issues such as maintenance difficulties after RSM failures,base floating caused by weightlessness,flexible deformation of structures due to large-scale operations,and multiple obstacles with uncertainty,fault-tolerant motion planning,motion planning considering base floating,motion planning under structural flexibility deformation,and obstacle avoidance motion planning are *** present,the increasingly complex OOS tasks have brought new challenges to the motion planning of *** challenges encompass motion planning for new mechanism configurations,dynamic motion planning,multi-RSM and multi-task planning,the improvement of motion planning efficiency,and the efficient implementation and precise process monitoring of *** the advancement of motion planning technology,RSM is poised to play an increasingly significant role in ISS and CSS.

关键词： redundant space manipulator on-orbit service motion planning main challenges

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：