检索结果-内蒙古大学图书馆

Study on the performance and mechanism of cobaltous ion removal from water by a high-efficiency strontium-doped hydroxyapatite adsorbent

引用

Environmental Science and Pollution Research 2024年第20期31卷 30059-30071页

作者： Zhu, Zongqiang Liu, Shuangshuang Zhu, Yinian He, Hao Zhang, Jun Mo, Xiaoxin Tang, Shen Fan, Yinming Zhang, Lihao Zhou, Xiaobin Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area Guilin University of Technology Guilin541004 China The Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control Guilin University of Technology Guilin541004 China Technical Innovation Center of Mine Geological Environmental Restoration Engineering in Southern Karst Area Nanning530022 China College of Environmental Science and Engineering Guilin University of Technology Guangxi Guilin541004 China

In this study, a high-efficiency strontium-doped hydroxyapatite (Sr-HAP) adsorbent was synthesized by a sol-gel method for removing cobaltous ions (Co(II)) from water. The effects of adsorbent dose, initial solution pH, initial Co(II) concentration and temperature on the removal performance of Co(II) were investigated. Experimental results indicated that the optimum Sr-HAP dose was 0.30 g/50 mL solution, the Sr-HAP adsorbent could effectively remove Co(II) in a wide pH range of 3–8. Increasing temperature was conducive to the adsorption, and the maximum Co(II) adsorption capacity by Sr-HAP reached 48.467 mg/g at 45 °C. The adsorption of Co(II) followed the pseudo-second-order kinetic model, indicating that the Co(II) adsorption by Sr-HAP was attributed mainly to chemisorption. The isothermal adsorption results showed that at lower Co(II) equilibrium concentration, the Langmuir model fitted the data better than the Freundlich model but opposite at higher Co(II) equilibrium concentration. Therefore, the adsorption of Co(II) was a process from monolayer adsorption to multilayer adsorption with the increase of the Co(II) equilibrium concentration. The diffusion analysis of Co(II) to Sr-HAP indicated that the internal diffusion and surface adsorption were the rate-controlled steps of Co(II) adsorption. Thermodynamic study demonstrated that the Co(II) adsorption process was spontaneous and endothermic. The mechanism study revealed that in addition to chemisorption, Sr-HAP also removed Co(II) ions from water via ion exchange and surface complexation. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Ions

来源：评论

学校读者我要写书评

暂无评论

Lightweight Neural Network-Based Infrared Image and Anomalous Heat Region Recognition for Electrical Equipment 18th

Lightweight Neural Network-Based Infrared Image and Anomalou...

引用

18th Annual Conference of China Electrotechnical Society, ACCES 2023

作者： Han, Zhikai Zhang, Jinglei Jia, Xin School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory of Complex System Control Theory and Application Tianjin300384 China

ISBN: (纸本)9789819710676

In order to accurately and quickly recognize electrical devices and abnormal heating parts under infrared conditions, we propose a lightweight neural network-based method for identifying electrical devices and their abnormal heating parts. First, we construct a fast target detection network for real-time detection. Second, we propose an efficient feature retention module to avoid the feature loss problem in multi-layer convolutional operations. In addition, we introduce an attention mechanism based on the coordinate information interaction strategy to localize the target more accurately. Finally, we use a lightweight weighted bidirectional feature pyramid network to improve the detection accuracy at different scales. Experimental results on a dataset of 12109 electrical infrared images containing six types of electrical devices and anomalously heated areas show that the proposed method achieves good results, with an average recognition accuracy of 93.9% and a processing speed of 222 frames/second. © Beijing Paike Culture Commu. Co., Ltd. 2024.

关键词： Infrared imaging

来源：评论

学校读者我要写书评

暂无评论

Path-Complete Barrier Functions for Safety of Switched Linear Systems 63

Path-Complete Barrier Functions for Safety of Switched Linea...

引用

63rd IEEE Conference on Decision and control, CDC 2024

作者： Anand, Mahathi Jungers, Raphael Zamani, Majid Allgower, Frank Institute for Systems Theory and Automatic Control University of Stuttgart Germany Université Catholique de Louvain Department of Mathematical Engineering Belgium University of Colorado Boulder United States

ISBN: (纸本)9798350316339

In this paper, we address the safety verification problem of switched linear dynamical systems under arbitrary switching via barrier functions. Our approach is based on a notion of path-complete barrier functions, which utilizes a collection of barrier functions associated with a directed labeled graph that can encode all the possible switching sequences. We show that path-complete barrier functions effectively generalize notions of common and multiple barrier functions studied in existing literature, and can potentially provide less conservative conditions for safety verification. We demonstrate that, for switched linear systems, the inequalities imposed via path-complete barrier functions can be easily encoded into simple linear matrix inequalities under some assumptions on the regions of interest and appropriately chosen templates for the barrier functions. We also study the relationship between path-complete barrier functions and common barrier functions, and show that for any path-complete graph with an admissible path-complete barrier function, one can derive a suitable (possibly non-smooth) common barrier function by utilizing the path-complete barrier function. Finally, we utilize several examples to illustrate the effectiveness of our approach, and briefly discuss the challenges that lay foundations for future research. © 2024 IEEE.

关键词： Directed graphs

来源：评论

学校读者我要写书评

暂无评论

Extremum Seeking for Single-Variable Static Map with Measurement Noise via A Time-Delay Approach 13

Extremum Seeking for Single-Variable Static Map with Measure...

引用

13th IEEE International Conference on CYBER Technology in Automation, control, and Intelligent Systems, CYBER 2023

作者： Zhao, Bowen Yang, Xuefei Fridman, Emilia Zhou, Bin Center for Control Theory and Guidance Technology Harbin Institute of Technology Harbin China School of Electrical Engineering Tel-Aviv University Israel

ISBN: (纸本)9798350315196

In this article, we introduce a time-delay approach to extremum seeking (ES) for scalar static quadratic maps with measurement noise. The approach involves transforming the ES system into a time-delay neutral type system with stochastic perturbations, which guarantees the stability of the original ES system. Using a Lyapunov-Krasovskii (L-K) method, explicit conditions are established for the mean-square ultimate boundedness of the ES control systems. These conditions are expressed in terms of LMIs and depend on the intensity of measurement noise, tuning parameters, and a known arbitrarily large constant L that bounds the 6th moment of the estimation error. Compared to existing results for ES with measurement noise obtained via qualitative analysis, our approach provides a quantitative analysis via a time-delay approach to averaging. A numerical example is provided to illustrate the efficiency of the proposed method. © 2023 IEEE.

关键词： Time delay

来源：评论

学校读者我要写书评

暂无评论

A Constant Force Tracking Strategy for Complex Surface Robots Fused with NURBS Speed Planning and Teaching/Learning Mode 5

A Constant Force Tracking Strategy for Complex Surface Robot...

引用

5th World Robot Conference Symposium on Advanced Robotics and Automation, WRC SARA 2023

作者： Jinjun, Duan Kunkun, Cui An, Guo Lingyu, Wang Yiming, Bin Minhong, Wan Qiulan, Huang Nanjing University of Aeronautics and Astronautics School of Mechatronics China Nanjing University of Aeronautics and Astronautics College of Mechanical and Electrical Engineering China Zhejiang Lab Hangzhou China Zhejiang University Control Theory and Control Egineering China

ISBN: (纸本)9798350307320

Compliance control technology is particularly im-portant in contact operations such as grinding and polishing, surface tracking, and medical diagnosis. The core technology achieves contact control of a constant force for complex heterogeneous surfaces. However, due to the unknown environmental stiffness/position and dynamic changes, there are some problems, such as poor position/force tracking accuracy and a low degree of complex surface fit. To solve the above problems, a piecewise trajectory planning algorithm based on speed controllable NURBS and a teaching and learning mode constant force tracking strategy based on position/force coordination planning are proposed in this paper. First, a NURBS segmented trajectory planning algorithm with controllable speed is proposed by combining the NURBS trajectory planning algorithm with the T-type speed interpolation algorithm, and constant force tracking control based on the FCPressNURBS instruction set is realized by combining the adaptive admittance control algorithm. Second, based on the concept of teaching and learning modes, the position/force tracking parameters are obtained by the compliant control method, and the learning ideas is used to optimize the constant force tracking trajectory of the robot. Finally, the algorithm is tested on the ROKAE xMate robot, and the results show that the proposed algorithm improves the constant force tracking accuracy of the robot to the complex contact surface in the heterogeneous environment and can realize the adaptive constant force tracking effect of the robot to the unknown environment. © 2023 IEEE.

关键词： Compliance control

来源：评论

学校读者我要写书评

暂无评论

Predefined time backstepping control of photovoltaic grid connected inverter 6

Predefined time backstepping control of photovoltaic grid co...

引用

2023 6th International Conference on Power Electronics and control engineering, ICPECE 2023

作者： Xu, Zhao Ji, Yuehui Chen, Jiaqi Liu, Junjie The School of Electrical Engineering and Automation Tianjin University of Technology Tianjin300384 China Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry Systems Tianjin300384 China

The large-scale grid connection of photovoltaic (PV) systems creates great hazards to the operation of power equipment and has a great impact on the stability and reliability of power systems. To achieve stable control and flexible management of PV grid connection, a predefined time adaptive backstepping control method based on the predefined boundary is proposed. Based on the predefined boundary time-varying function, the user's predefined boundary design of the control signal is accomplished to ensure the boundedness of the global signal, which is independent of the initial state of the system. The controller with predefined boundaries is designed based on backstepping control, and the estimation and compensation of perturbations are attained based on adaptive control. The global predefined time stability of the predefined boundary of the closed-loop system is certified using the Lyapunov function. Simulation studies attest to the performance of the predefined time control strategy. © Published under licence by IOP Publishing Ltd.

关键词： Lyapunov functions

来源：评论

学校读者我要写书评

暂无评论

Adaptive Sampling Offspring Generation Strategy for Multi-objective Optimization 8

Adaptive Sampling Offspring Generation Strategy for Multi-ob...

引用

2024 8th International Conference on Machine Vision and Information Technology, CMVIT 2024

作者： Wang, Ningning Fan, Jun Liu, Tingrui Kang, Honglong Zhang, Wenbo Song, Shenmin Center for Control Theory and Guidance Technology Harbin Institute of Technology Harbin China Army Aviation Institute Beijing China Beijing Institute of Astronautical Systems Engineering Beijing China

A covariance adaptive sampling offspring generation strategy (CASS) based on fuzzy clustering is proposed, and a multi-objective distribution estimation algorithm (MEDCA) based on this strategy is introduced. The GK-FCM clustering partitioning strategy is designed to build a Gaussian model for each individual, collectively approximating the manifold of the Pareto solution set and generating offspring through sampling. The introduction of an individual's survival generation adapts the individual's preference for exploration and exploitation. This is achieved by incorporating it as a scaling factor of the covariance matrix in the sampling model, in order to satisfy the individual's preferences for development and exploration in different evolutionary stages. This method significantly improves the performance of MEDCA in solving complex multi-objective optimization problems through covariance matrix adaptation sampling strategy and scaling factor adaptation strategy. The experimental results demonstrate the advantages of MEDCA in the application of offspring generation strategies during model sampling. © Published under licence by IOP Publishing Ltd.

关键词： Covariance matrix

来源：评论

学校读者我要写书评

暂无评论

Distributed-Observer-Based on Longitudinal Flight control for Hypersonic Vehicle 42

Distributed-Observer-Based on Longitudinal Flight Control fo...

引用

42nd Chinese control Conference, CCC 2023

作者： Ji, Yuehui Zhao, Yiming Chen, Jiaqi Liu, Junjie Gao, Qiang School of Electrical Engineering and Automation Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin300384 China

ISBN: (纸本)9789887581543

An output feedback control is investigated to achieve stable tracking of velocity and altitude in hypersonic flight vehicle in the paper. A distributed observer is proposed to estimate the unmeasurable flight path angel and angle of attack through a strongly connected directed network topology. Then, a nonlinear control is addressed on the longitudinal dynamics of a rigid hypersonic flight vehicle (HFV) with partial measurable states and the estimated states. The system dynamic is divided into the altitude subsystem and the velocity subsystem. In the altitude subsystem, the backstepping design is proposed for constructing the controllers utilizing the estimated states. The nonlinear dynamic inversion controller is introduced to accomplish the velocity tracking. Finally, numerical simulations verify the effectiveness of the proposed control scheme in providing favorable tracking performance and exact state estimation ability. © 2023 Technical Committee on control theory, Chinese Association of Automation.

关键词： Hypersonic vehicles

来源：评论

学校读者我要写书评

暂无评论

Smooth Time-Varying Feedback control of Nonholonomic Systems with Applications to the Attitude control of Underactuated Spacecraft

引用

Guidance, Navigation and control 2024年第1期4卷 86-101页

作者： Bin Zhou Kang-Kang Zhang Center for Control Theory and Guidance Technology Harbin Institute of Technology Harbin 150001 P.R.China Department of Mechanical Engineering University of Hong Kong Hong KongP.R.China

This paper studies the control of chained nonholonomic systems by using smooth time-varying ***,by using a time-varying state transformation,the chained nonholonomic system is transformed into a linear time-varying ***,with the aid of some properties of a class of parametric Lyapunov equations and time-varying systems theory,smooth time-varying state feedback controller is developed to ensure the exponential convergence of both the system states and *** from existing results,the design parameters in the proposed control strategy are independent of the initial conditions of the ***,as an application of the proposed smooth time-varying feedback,the attitude control problem for underactuated axisymmetric spacecraft is ***,a numerical simulation is presented to validate the effectiveness of the proposed method.

关键词： Nonholonomic systems underactuated spacecraft attitude control smooth time-varying feedback parametric Lyapunov equations

来源：评论

学校读者我要写书评

暂无评论

Research of line-of-sight angle on aero-optic imaging deviation for vehicles flying at 40—60 km

引用

Optoelectronics Letters 2023年第4期19卷 242-247页

作者： XU Liang ZHAO Shiwei WANG Tao Tianjin Key Laboratory of Complex Control Theory and Application School of Electronic Engineering and AutomationTianjin University of TechnologyTianjin 300384China Foreign Cooperation Projects Department PetroChina Dagang Oilfield CompanyTianjin 300280China

Aero-optical imaging deviation is a kind of optical effect,aiming at a conical *** paper analyzes the influence of the aircraft on the imaging deviation with the change of altitude and line-of-sight *** this paper,the relationships between imaging deviation and altitude as well as line-of-sight angle are analyzed,and the coupling relationship between altitude and line-of-sight angle is *** give the imaging deviation results of 5°—75°line-of-sight *** analysis shows that when the line-of-sight angle is in the range of 5°—35°,the imaging deviation is more sensitive,while the line-of-sight angle is in the range of 35°—75°,the imaging deviation is relatively flat,and the imaging deviation does not gradually decrease with the increase of line-of-sight angle,but there is a turning point in the middle of 5°—75°.The imaging deviation decreases first and then increases,and the turning point of line-of-sight angle is closely related to height.

关键词： deviation angle turning

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：