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Study on force chain evolution of rice straw with different length during vibrational compression

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Particuology 2024年第2期85卷 310-322页

作者： Han Tang wenlong Xu Guixuan Zhu Changsu Xu Jinwu wang College of Engineering Northeast Agricultural UniversityHarbin150030China

This paper explores the mechanism of force chain evolution and voidage change under vibrational and non-vibrational compression conditions of rice straw of different *** were used to explore the force chain evolution and voidage variation mechanism under different *** re-sults show that under non-vibrational compression,the strong force chain passes from top to bottom in vertical direction and from center to periphery in tangential *** vibrational compression,the force chain passes from top and bottom to center in vertical direction and the force chain evolves from outer ring to interior and exterior in tangential *** number of strong chains,voidage and standard deviation of the mean pressure under vibratory compression are lower than the values under non-vibratory *** promotes stress transfer and enhancement,velocity enhancement and density *** study analyzes the mechanical properties of different lengths straw during vibrational and non-vibrational compression from a detailed viewpoint.

关键词： Straw compression Voidage Discrete element method Mechanical properties Force chain transmission

Surface integrity evolution during creep feed profile grinding ofγ-TiAl blade tenon

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Chinese Journal of Aeronautics 2024年第8期37卷 496-512页

作者： Tao CHEN Xiaowei wang Biao ZHAO wenfeng DING Jiuhua XU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Gamma titanium-aluminum(γ-TiAl)intermetallic compounds are increasingly used in manufacturing key hot-end components(e.g.,blade tenon)in aero engines due to their high specific strength and lightweight *** feed profile grinding(CFPG)as a crucial precision process that is applied to produce the final profile of the blade ***,sudden surface burns and microcracks of machined c-TiAl blade tenon often occur because of its low plasticity and high strength during grinding processes,leading to poor surface *** this work,CFPG experiments based on the profile characteristics ofγ-TiAl blade tenon were performed and an associated undeformed chip thickness model considering grain–workpiece contact condition was established to explore the evolution of the surface ***,the surface integrity was analyzed at different positions of the blade tenon in terms of surface roughness and morphology,metallographic structure,microhardness,and residual *** show that the profile characteristics of blade tenon have a significant influence on machined surface integrity because of the thermomechanical effect at various detecting *** residual stress was established based on the undeformed chip thickness model considering the profile structure,with a prediction error of 10%–15%.The thermomechanical effect is more obvious at the bottom area,where the surface roughness,work hardening degree,and subsurface plastic deformation range are the largest,while the values at the bevel area are the *** on the undeformed chip thickness model,a residual stress finite element simulation was conducted by employing thermomechanical coupled *** addition,the error between the simulation and the experiment was between 10%–15%.Strain and strain rate equations were established through the relationship between material displacement and *** average strain and strain rate of the ground surface when ap is 1.0 mm are 18.8%and 33.2%l

关键词： Gamma titanium-aluminum intermetallic compounds Blade tenon Creep feed profile grinding Surface integrity Thermomechanical effect

Command filtered integrated estimation guidance and control for strapdown missiles with circular field of view

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Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China China Research and Development Academy of Machinery Equipment Beijing 100089China Northwest Industries Group CO. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown *** threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV *** boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular ***,the nonlinear adaptive controller is designed to estimate the changing aerodynamic *** generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking ***,the command filters are used to solve the"differential expansion"problem during the backstepping *** Lyapunov theory is used to prove the stability of the overall closed-loop IEGC ***,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： Integrated estimation guidance and control Circular field-of-view Time-varying integral barrier Lyapunov function Command filtered backstepping control Nonlinear adaptive control Extended state observer

Configuration and Kinematics of a 3-DOF Generalized Spherical Parallel Mechanism for Ankle Rehabilitation

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 176-188页

作者： Jianjun Zhang Shuai Yang Chenglei Liu Xiaohui wang Shijie Guo School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China Key Laboratory of Robot Perception and Human-Machine Fusion Tianjin 300401China

The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation ***,this study equates the human ankle to the UR model and proposes a novel three degrees of freedom(3-DOF)generalized spherical parallel mechanism for ankle *** parallel mechanism has two spherical centers corresponding to the rotation centers of tibiotalar and subtalar *** screw theory,the mobility of the parallel mechanism,which meets the requirements of the human ankle,is *** inverse kinematics are presented,and singularities are identified based on the Jacobian *** workspaces of the parallel mechanism are obtained through the search method and compared with the motion range of the human ankle,which shows that the parallel mechanism can meet the motion demand of ankle ***,based on the motion-force transmissibility,the performance atlases are plotted in the parameter optimal design space,and the optimum parameter is obtained according to the demands of practical *** results show that the parallel mechanism can meet the motion requirements of ankle rehabilitation and has excellent kinematic performance in its rehabilitation range,which provides a theoretical basis for the prototype design and experimental verification.

关键词： Ankle rehabilitation Parallel mechanism Kinematic analysis Parameter optimization

Coordinated Dispatch Based on Distributed Robust Optimization for Interconnected Urban Integrated Energy and Transmission Systems

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 840-851页

作者： Wei Xu Yufeng Guo Tianhui Meng Yingwei wang Jilai Yu the School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001China

To improve the economic efficiency of urban integrated energy systems(UIESs)and mitigate day-ahead dispatch uncertainty,this paper presents an interconnected UIES and transmission system(TS)model based on distributed robust ***,interconnections are established between a TS and multiple UIESs,as well as among different UIESs,each incorporating multiple energy *** Bregman alternating direction method with multipliers(BADMM)is then applied to multi-block problems,ensuring the privacy of each energy system operator(ESO).Second,robust optimization based on wind probability distribution information is implemented for each ESO to address dispatch *** column and constraint generation(C&CG)algorithm is then employed to solve the robust ***,to tackle the convergence and practicability issues overlooked in the existing studies,an external C&CG with an internal BADMM and corresponding acceleration strategy is ***,numerical results demonstrate that the adoption of the proposed model and method for absorbing wind power and managing its uncertainty results in economic benefits.

关键词： Distributed robust optimization distributionally robust dispatch urban integrated energy system transmission system external column and constraint generation(C&CG) internal Bregman alternating direction method with multipliers(BADMM)

Aerodynamic/control integrated optimization method for unpowered high-speed vehicle configuration design

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Chinese Journal of Aeronautics 2024年第7期37卷 153-167页

作者： Xin PAN Linlin wang Li LI Lulu JIANG Gang CHEN State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China Shannxi Key Laboratory for Environment and Control of Flight Vehicle School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China Beijing Institute of Space Long March Vehicle Beijing 100076China AVIC Xi’an Aeronautics Computing Technique Research Institute Xi’an 710068China

The unpowered high-speed vehicle experiences a significant coupling between the disciplines of aerodynamics and control due to its characteristics of high flight speed and extensive maneuverability within large *** conventional aircraft conceptual design process follows a sequential design approach,and there is an artificial separation between the disciplines of aerodynamics and control,neglecting the coupling effects arising from their *** a result,this design process often requires extensive iterations over long periods when applied to high-speed vehicles,and may not be able to effectively achieve the desired design *** enhance the overall performance and design efficiency of high-speed vehicles,this study integrates the concept of Active Control Technology(ACT)from modern aircraft into the philosophy of aerodynamic/control integrated *** integrated optimization strategies,with differences in coupling granularity,have been ***,these strategies are put into action on a biconical vehicle that operates at Mach *** results reveal that the comprehensive performance of the synthesis optimal model derived from the aerodynamic/control integrated optimization strategy is improved by 31.76%and 28.29%respectively compared to the base model under high-speed conditions,demonstrating the feasibility and effectiveness of the method and optimization strategies ***,in comparison to the single-stage strategy,the multi-stage strategy takes into deeper consideration the impact of control *** a result,the control performance of the synthesis opti-mal model derived from the multi-stage strategy improves by 13.99%,whereas the single-stage strategy only achieves a 5.79%*** method enables a fruitful interaction between aerodynamic configuration design and control system design,leading to enhanced overall performance and design ***,it improves the controllability of high-sp

关键词： Aerodynamic/Control Integrated Optimization MDO High-speed vehicle Shape Optimization Controllability

Cortical Organoid-on-a-Chip with Physiological Hypoxia for Investigating Tanshinone IIA-Induced Neural Differentiation

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Research 2024年第3期2023卷 457-468页

作者： Yue Zhi Yujuan Zhu Jinglin wang Junqi Zhao Yuanjin Zhao Department of Rheumatology and Immunology Nanjing Drum Tower HospitalClinical Medical College of Traditional Chinese and Western MedicineNanjing University of Chinese MedicineNanjing210023China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China Shenzhen Research Institute Southeast UniversityShenzhen518038China

Cortical organoids represent cutting-edge models for mimic human brain development during the early and even middle stage of pregnancy, while they often fail to recreate the complex microenvironmental factors, such as physiological hypoxia. Herein, to recapitulate fetal brain development, we propose a novel cortical organoid-on-a-chip with physiological hypoxia and further explore the effects of tanshinone IIA (Tan IIA) in neural differentiation. The microfluidic chip was designed with a micropillar array for the controlled and efficient generation of cortical organoids. With low oxygen, the generated cortical organoids could recapitulate key aspects of early-gestational human brain development. Compared to organoids in normoxic culturing condition, the promoted neurogenesis, synaptogenesis and neuronal maturation were observed in the present microsystem, suggesting the significance of physiological hypoxia in cortical development. Based on this model, we have found that Chinese herbal drug Tan IIA could promote neural differentiation and maturation, indicating its potential therapeutic effects on neurodevelopmental disorders as well as congenital neuropsychiatric diseases. These results indicate that the proposed biomimetic cortical organoid-on-a-chip model with physiological hypoxia can offer a promising platform to simulate prenatal environment, explore brain development, and screen natural neuroactive components.

关键词： promoted herbal cutting

Recent Research Progress of Paper-Based Supercapacitors Based on Cellulose

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Energy & Environmental Materials 2024年第3期7卷 345-373页

作者： Chuanyin Xiong Tianxu wang Jing Han zhao Zhang Yonghao Ni College of Bioresources Chemical&Materials Engineering Shaanxi University of Science and TechnologyXi'an 710021China School of Materials Science and Engineering Tianjin Polytechnic UniversityTianjin 300387China Department of Chemical and Biomedical Engineering The University of MaineOronoMaine 04469USA University of New Brunswick Limerick Pulp&Paper CtrFredericton New Brunswick E3B 5A3Canada

In recent years,paper-based functional materials have received extensive attention in the field of energy storage due to their advantages of rich and adjustable porous network structure and good *** an important energy storage device,paper-based supercapacitors have important application prospects in many fields and have also received extensive attention from researchers in recent *** present,researchers have modified and regulated paper-based materials by different means such as structural design and material composition to enhance their electrochemical storage *** development of paper-based supercapacitors provides an important direction for the development of green and sustainable ***,it is of great significance to summarize the relevant work of paper-based supercapacitors for their rapid development and *** this review,the recent research progress of paper-based supercapacitors based on cellulose was summarized in terms of various cellulose-based composites,preparation skills,and electrochemical ***,some opinions on the problems in the development of this field and the future development trend were *** is hoped that this review can provide valuable references and ideas for the rapid development of paper-based energy storage devices.

关键词： cellulose electrochemical performance flexibility paper-based supercapacitor porous

Transient state analysis of a rub-impact rotor system during maneuvering flight

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Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： Jun wang Yunfei LIU Zhaoye QIN Liang MA Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： Maneuvering flight Rub impact Rotor system Dynamic response Impact response