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In vivo whole brain photoacoustic microscopy through a transparent ultrasound transducer

Chinese Optics Letters 2025年第2期23卷 38-43页

作者： Chen Liang Junwei Wu Hangbing Peng Ljun Deng Yiqin Lin Zhongwen Cheng Luming Zeng Xuanrong Ji Jiangxi Provincial Key Laboratory of Advanced Electronic Materials and Devices Jiangxi Science and Technology Normal University Nanchang 33038China State Key Laboratory of Precision Electronics Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China

Brain imaging techniques provide in vivo insight into structural and functional phenotypes that are physiologically and clinically ***,most existing brain imaging techniques suffer from balancing trade-offs among the temporal and spatial resolutions as well as the field of view(FOV).Here,we proposed a high-resolution photoacoustic microscopy(PAM)system based on a transparent ultrasound transducer(TUT).The system not only retains the advantage of the fast imaging speed of pure optical scanning but also has an imaging FOV of up to 20 mm×20 mm,which can easily enable rapid imaging of the whole mouse brain in *** on experimental validation of brain injury,glioma,and cerebral hemorrhage in mice,the system has the capability to visualize the vascular structure and hemodynamic changes in the cerebral ***-based PAM provides an important research tool for rapid multi-parametric brain imaging in small animals,providing a solid foundation for the study of brain diseases.

关键词： photoacoustic microscopy transparent ultrasound transducer whole brain imaging.

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An Iterative Tuning Method for Feedforward control of Parallel Manipulators Considering Nonlinear Dynamics

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Chinese Journal of Mechanical Engineering 2025年第1期38卷 295-305页

作者： Xiaojian Wang Jun Wu Beijing Key Laboratory of Transformative High-end Manufacturing Equipment and Technology Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology in Advanced Equipment and Institute of Manufacturing Engineering Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Feedforward control is one of the most effective control techniques to increase the robot’s tracking ***,most of the dynamic models used in the feedforward controllers are linearly simplified such that the nonlinear and time-varying characteristics of dynamics in the workspace are *** this paper,an iterative tuning method for feedforward control of parallel manipulators by taking nonlinear dynamics into account is *** on the robot rigid-body dynamic model,a feedforward controller considering the dynamic nonlinearity is *** iterative tuning method is given to iteratively update the feedforward controller by minimizing the root mean square(RMS)of the joint errors at each *** effectiveness and extrapolation capability of the proposed method are validated through the experiments on a 2-DOF parallel *** research proposes an iterative tuning method for feedforward control of parallel manipulators considering nonlinear dynamics,which has better extrapolation capability in the whole workspace of manipulators.

关键词： Parallel manipulator Dynamic model Feedforward control Iterative learning control Parameter design

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Synthesis of size-controlled and dispersible Sm_(2)Fe_(17)N_(3) magnetic particles by reduction diffusion process using molten salt

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Journal of Rare Earths 2024年第11期42卷 2105-2111,I0004页

作者： Junhua Xi Zhi Yang Muhammad Haseeb Yuanyuan Chen Xiaofeng Nie Liying Cong Qiong Wu Enfeng Fu Hongguo Zhang Weiqiang Liu Ming Yue Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing100124China

The synthesis of size-controlled Sm_(2)Fe_(17) magnetic particles is a prerequisite for the fabrication of highperformance Sm_(2)Fe_(17)N_(3) permanent magnetic ***,Sm_(2)Fe_(17) was synthesized using a costeffective reduction-diffusion *** calcium chloride molten salt was introduced to control the particle size and achieve a single phase of Sm_(2)Fe_(17).The effects of reduction-diffusion reaction temperature and the amount of added calcium chloride on the phase constitution and microstructure of the final product of reduction-diffusion were systematically *** an appropriate amount of calcium chloride can effectively inhibit the overgrowth and sintering of the reduced *** employing the strategy of adding 20 wt% of calcium chlorides into the green compacts,we were able to successfully synthesize uniform Sm_(2)Fe_(17) particles that are well-dispersed,with an average size of 2.2 μ***,by combining the optimal reduction-diffusion conditions and the nitriding process,the hard magnetic Sm_(2)Fe_(17)N_(3) material was successfully *** study could be useful for the development of high-performance Sm_(2)Fe_(17)N_(3) magnetic materials utilizing reduction-diffusion technology.

关键词： Sm_(2)Fe_(17)N_(3) Reduction-diffusion Rare earths Permanent magnets Molten salt

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Spectrum analysis of interval process model and its application in uncertain vibration analysis

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Science China(Technological Sciences) 2024年第8期67卷 2549-2564页

作者： LI JinWu JIANG Chao NI BingYu State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

In recent years, the authors have extended the traditional interval method into the time dimension to develop a new mathematical tool called the “interval process model” for quantifying time-varying or dynamic uncertainties. This model employs upper and lower bounds instead of precise probability distributions to quantify uncertainty in a parameter at any given time point. It is anticipated to complement the conventional stochastic process model in the coming years owing to its relatively low dependence on experimental samples and ease of understanding for engineers. Building on our previous work, this paper proposes a spectrum analysis method to describe the frequency domain characteristics of an interval process, further strengthening the theoretical foundation of the interval process model and enhancing its applicability for complex engineering problems. In this approach, we first define the zero midpoint function interval process and its auto/cross-power spectral density(PSD) functions. We also deduce the relationship between the auto-PSD function and the auto-covariance function of the stationary zero midpoint function interval process. Next, the auto/cross-PSD function matrices of a general interval process are defined, followed by the introduction of the concepts of PSD function matrix and cross-PSD function matrix for interval process vectors. The spectrum analysis method is then applied to random vibration problems, leading to the creation of a spectrum-analysis-based interval vibration analysis method that determines the PSD function for the system displacement response under stationary interval process excitations. Finally, the effectiveness of the formulated spectrum-analysis-based interval vibration analysis approach is verified through two numerical examples.

关键词： interval process spectrum analysis power spectral density(PSD) time-varying uncertainty uncertain vibration analysis

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Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of Materials Science & technology 2024年第1期168卷 239-249页

作者： Fawei Tang Chao Hou Hao Lu Zhi Zhao Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were *** on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been *** study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation Thermal stabilization Solute concentration Grain size

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Surrogate-based buckling analysis and optimization of composite plates modeled using a novel nonlinear function to describe fiber orientation

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Chinese Journal of Aeronautics 2025年第5期38卷 460-474页

作者： Yang LIU Xinjun LIU Institute of Nuclear and New Energy Technology Tsinghua University State Key Laboratory of Tribology in Advanced Equipment Tsinghua University Beijing Key Laboratory of Transformative High-End Manufacturing Equipment and Technology Department of Mechanical EngineeringTsinghua University

The stiffness properties of variable stiffness(VS) composite plates can be controlled by manipulating the variation in the fiber angle, thereby significantly improving their buckling properties. Nonlinear fiber paths have attracted attention in the field of composites due to their large design space. The major challenge in adopting nonlinear fiber paths is obtaining a fiber path function within the design space that is easily computable and efficiently yields the highest buckling load of a VS plate. In this investigation, an innovative nonlinear function was proposed to describe the fiber orientation by integrating a center fiber angle into the conventional linear function. The parameters of the nonlinear function can directly represent the fiber angles at a fixed position. This novel approach has promising potential for improving the optimal efficiency of fiber paths because the linear and nonlinear functions are simplified with two identical path parameters. Furthermore, a multilevel optimization method was developed by combining finite element analysis(FEA) with an adaptive radial basis function(RBF) surrogate model, and it was found that the number of FEA cases could be reduced by iteratively inheriting training points. The integration of this nonlinear function with a surrogate model is a significant advancement in the structural optimization of composites. Subsequently, the optimal linear and nonlinear fiber paths were computed to maximize the buckling load of VS plates. The FEA results show that the computational efficiency was greatly improved by the proposed nonlinear function and optimization method. The buckling resistance could be enhanced by the nonlinear fiber path, and the reinforcement mechanism was the redistribution and reduction of in-plane compressive stress.

关键词： Composites Variable stiffness Curvilinear fiber Buckling Optimization

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A Tutorial on Quantized Feedback control

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue Fu IEEE the School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control

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Analysis and Optimization of the Electrohydraulic Forming Process of Sinusoidal Corrugation Tubes

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Fluid Dynamics & Materials Processing 2024年第4期20卷 873-887页

作者： Da Cai Yinlong Song Hao Jiang Guangyao Li Junjia Cui State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan UniversityChangsha410082China

Aluminum alloy thin-walled structures are widely used in the automotive industry due to their advantages related to light weight and *** can be produced at room temperature by the electrohydraulic forming *** the present study,the influence of the related parameters on the forming quality of a 6063 aluminum alloy sinusoidal corrugation tube has been *** particular,the orthogonal experimental design(OED)and central composite design(CCD)methods have been *** the range analysis and variance analysis of the experimental data,the influence degree of wire diameter(WD)and discharge energy(DE)on the forming quality was *** regression analysis was performed using the response surface methodology.A prediction model for the attaching-die state coefficient was established *** following optimal arrangement of parameters was obtained(WD=0.759 mm,DE=2.926 kJ).The attaching-die state coefficient reached the peak value of *** optimized wire diameter and discharge energy for a better attaching-die state could be screened by CCD compared with *** response surface method in CCD was more suitable for the design and optimization of the considered process parameters.

关键词： Electrohydraulic forming aluminum alloy tube process parameters attaching-die state 1 Introduction

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Collaborative Improvement of Structure Shape and Surface Integrity in Titanium Alloy Hole Burnishing

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Chinese Journal of Mechanical Engineering 2025年第1期38卷 186-205页

作者： Jiahui Liu Pingfa Feng Zibiao Wang Jianfu Zhang Feng Feng Xiangyu Zhang Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Division of Advanced Manufacturing Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China

In the aerospace field,hole burnishing enhancement plays an essential role in improving the service performance of load-bearing *** satisfy the assembly accuracy and strength requirements,the structure shape and surface integrity must be considered simultaneously during the enhancement *** current manufacturing process of hole burnishing has a relatively weak balance between the structure shape and surface integrity;therefore,it is necessary to analyze the mechanism and optimize the parameters to improve the strengthening effect of the *** this study,a two-dimensional longitudinal simplified model for the hole burnishing process was established,and the reasons for the surface roughness improvement of the hole wall and material accumulation on the upper surface were *** were conducted to determine the influence of the burnishing parameters on the structure shape(material accumulation,shape contour,and roundness)and surface integrity(surface roughness,residual stress,and surface hardness),based on the opposite requirements of improving the structure shape and surface integrity for the burnishing depth(BD).The results showed that with an increase in the BD,the structure shape deteriorated,whereas the surface integrity *** behavior verification experiments were conducted,and parameter selection schemes for the collaborative improvement of the structure shape and surface integrity were *** the holes of titanium alloy TB6(Ti-10V-2Fe-3Al),the fatigue life can be increased by 162%when the BD,spindle speed,and feed rate were 0.20 mm,200 r/min,and 0.2 mm/r,respectively.

关键词： Hole burnishing Surface roughness Material accumulation Structure shape Titanium alloy Fatigue life

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Current Status of Patent Research on Picking End Effector

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Recent Patents on Engineering 2024年第6期18卷 39-54页

作者： Wu, Xilong Xie, Baocheng Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China

Background: Fruit and vegetable picking, as the most important part of fruit and vegetable production, is a labor-intensive industry. Fruit and vegetable picking robots can effectively improve the efficiency of picking and reduce labor requirements. As the most important part of the picking robot, the picking end-effector effectively plays a key role in improving the picking efficiency and ensuring the wholeness of the fruit. Therefore, the development trend of picking end ef-fectors has received more and more attention. Objective: The study aimed to solve the problems of high labor consumption and low picking efficiency of manual picking;thus, the grasping method of the picking end effector has been continu-ously improved. Methods: This article has presented various representative patents related to the picking end effec-tor, such as the suction end effector, multi-finger end effector, and bionic end effector. Results: Through the investigation of a large number of picking end effector patents, the current problems, such as low accuracy and large clamping damage, are summarized and analyzed. In addi-tion, the future trends of fruit and vegetable picking end effectors are discussed. Conclusion: The optimization of the picking end effector is conducive to reducing manual labor and improving the picking rate of fruits and vegetables. More relevant patents will be invented in the future. © 2024 Bentham Science Publishers.

关键词： Bionics

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