The structural,thermal expansion,and magnetic properties of the Nc/2^16.5^0.5 compound are investigated by means of x-ray diffraction and magnetization measurements.The Nd2^616.560.5 compound has a rhombohedral Th2Znn...The structural,thermal expansion,and magnetic properties of the Nc/2^16.5^0.5 compound are investigated by means of x-ray diffraction and magnetization measurements.The Nd2^616.560.5 compound has a rhombohedral Th2Znn-type structure.There exists a small negative thermal expansion resulting from a spontaneous magnetostriction in the magnetic state of the^2^16.5 Cr0.5 compound.The average thermal expansion coefficient is-1.06×10^6/K in a temperature range 299-394 K.The spontaneous magnetostrictive deformation and the Curie temperature are discussed.展开更多
Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17...Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17)-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_(16)Cr compound. The average thermal expansion coefficient is-0.794 × 10^(-5)/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.展开更多
Rehabilitation using exoskeleton robots can effectively remediate dysfunction and restore post-stroke survivors’ physical ability. However, low kinematic compatibility and poor self-participation of post-stroke patie...Rehabilitation using exoskeleton robots can effectively remediate dysfunction and restore post-stroke survivors’ physical ability. However, low kinematic compatibility and poor self-participation of post-stroke patients in rehabilitation restrict the outcomes of exoskeleton-based therapy. The study presents an Unpowered Shoulder Complex Exoskeleton (USCE), consisting of Shoulder Girdle Mechanism (SGM), Ball-and-Socket Joint Mechanism (BSM), Gravity Compensating Mechanism (GCM) and Adjustable Alignment Design (AAD), to achieve self-rehabilitation of shoulder via energy transfer from the healthy upper limb to the affected counterpart of post-stroke hemiplegic patients. The SGM and AAD are designed to improve the kinematic compatibility by compensating for displacements of the glenohumeral joint with the adaptable size of USCE for different wearers. The BSM and GCM can transfer the body movement and energy from the healthy half of the body to the affected side without external energy input and enhance the self-participation with sick posture correction. The experimental results show that the USCE can provide high kinematic compatibility with 90.9% movement similarity between human and exoskeleton. Meanwhile, the motion ability of a post-stroke patient’s affected limb can be increased through energy transfer. It is expected that USCE can improve outcomes of home-based self-rehabilitation.展开更多
Exoskeleton robots have demonstrated the potential to rehabilitate stroke dyskinesia.Unfortunately,poor human-machine physiological coupling causes unexpected damage to human of muscles and joints.Moreover,inferior hu...Exoskeleton robots have demonstrated the potential to rehabilitate stroke dyskinesia.Unfortunately,poor human-machine physiological coupling causes unexpected damage to human of muscles and joints.Moreover,inferior humanoid kinematics control would restrict human natural kinematics.Failing to deal with these problems results in bottlenecks and hinders its application.In this paper,the simplified muscle model and muscle-liked kinematics model were proposed,based on which a soft wrist exoskeleton was established to realize natural human interaction.Firstly,we simplified the redundant muscular system related to the wrist joint from ten muscles to four,so as to realize the human-robot physiological coupling.Then,according to the above human-like musculoskeletal model,the humanoid distributed kinematics control was established to achieve the two DOFs coupling kinematics of the wrist.The results show that the wearer of an exoskeleton could reduce muscle activation and joint force by 43.3%and 35.6%,respectively.Additionally,the humanoid motion trajectories similarity of the robot reached 91.5%.Stroke patients could recover 90.3%of natural motion ability to satisfy for most daily activities.This work provides a fundamental understanding on human-machine physiological coupling and humanoid kinematics control of the exoskeleton robots for reducing the post-stroke complications.展开更多
基金the National Natural Science Foundation of China under Grant Nos 50871074 and 61474082the Henan Agricultural University Start-up under Grant No 20190703Y00005.
文摘The structural,thermal expansion,and magnetic properties of the Nc/2^16.5^0.5 compound are investigated by means of x-ray diffraction and magnetization measurements.The Nd2^616.560.5 compound has a rhombohedral Th2Znn-type structure.There exists a small negative thermal expansion resulting from a spontaneous magnetostriction in the magnetic state of the^2^16.5 Cr0.5 compound.The average thermal expansion coefficient is-1.06×10^6/K in a temperature range 299-394 K.The spontaneous magnetostrictive deformation and the Curie temperature are discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50871074 and 61474082
文摘Structural, thermal expansion, and magnetic properties of the Dy_2Fe_(16)Cr compound are investigated by means of x-ray diffraction and magnetization measurements. The Dy_2Fe_(16)Cr compound has a hexagonal Th_2Ni_(17)-type structure. There exists a negative thermal expansion resulting from a strong spontaneous magnetostriction in the magnetic state of the Dy_2Fe_(16)Cr compound. The average thermal expansion coefficient is-0.794 × 10^(-5)/K in the temperature range 292–407 K. The spontaneous magnetostrictive deformation and the Curie temperature are discussed.
基金supported by the National Key R&D Program of China(Grant No.2016YFE0206200)the National Natural Science Foundation of China(Grant Nos.U1908215,91848201,61821005 and 61973316)Liaoning Revitalizaiton Talents Program(Grant No.XLYC2002014).
文摘Rehabilitation using exoskeleton robots can effectively remediate dysfunction and restore post-stroke survivors’ physical ability. However, low kinematic compatibility and poor self-participation of post-stroke patients in rehabilitation restrict the outcomes of exoskeleton-based therapy. The study presents an Unpowered Shoulder Complex Exoskeleton (USCE), consisting of Shoulder Girdle Mechanism (SGM), Ball-and-Socket Joint Mechanism (BSM), Gravity Compensating Mechanism (GCM) and Adjustable Alignment Design (AAD), to achieve self-rehabilitation of shoulder via energy transfer from the healthy upper limb to the affected counterpart of post-stroke hemiplegic patients. The SGM and AAD are designed to improve the kinematic compatibility by compensating for displacements of the glenohumeral joint with the adaptable size of USCE for different wearers. The BSM and GCM can transfer the body movement and energy from the healthy half of the body to the affected side without external energy input and enhance the self-participation with sick posture correction. The experimental results show that the USCE can provide high kinematic compatibility with 90.9% movement similarity between human and exoskeleton. Meanwhile, the motion ability of a post-stroke patient’s affected limb can be increased through energy transfer. It is expected that USCE can improve outcomes of home-based self-rehabilitation.
基金supported by National Key R&D Program of China(Grant No.2016YFE0206200)the National Natural Science of China(Grant Nos.61821005,61703395,and 61727811)+2 种基金the Sichuan Science and Technology Program(Grant No.20SYSX0276)Natural Science Foundation of Liaoning Province of China(Grant No.20180520035)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2019205).
文摘Exoskeleton robots have demonstrated the potential to rehabilitate stroke dyskinesia.Unfortunately,poor human-machine physiological coupling causes unexpected damage to human of muscles and joints.Moreover,inferior humanoid kinematics control would restrict human natural kinematics.Failing to deal with these problems results in bottlenecks and hinders its application.In this paper,the simplified muscle model and muscle-liked kinematics model were proposed,based on which a soft wrist exoskeleton was established to realize natural human interaction.Firstly,we simplified the redundant muscular system related to the wrist joint from ten muscles to four,so as to realize the human-robot physiological coupling.Then,according to the above human-like musculoskeletal model,the humanoid distributed kinematics control was established to achieve the two DOFs coupling kinematics of the wrist.The results show that the wearer of an exoskeleton could reduce muscle activation and joint force by 43.3%and 35.6%,respectively.Additionally,the humanoid motion trajectories similarity of the robot reached 91.5%.Stroke patients could recover 90.3%of natural motion ability to satisfy for most daily activities.This work provides a fundamental understanding on human-machine physiological coupling and humanoid kinematics control of the exoskeleton robots for reducing the post-stroke complications.
