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An Optimization System for Intent Recognition Based on an Improved KNN Algorithm with Minimal Feature Set for Powered Knee Prosthesis

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Journal of Bionic Engineering 2023年第6期20卷 2619-2632页

作者： Yao Zhang xu Wang Haohua xiu Lei Ren yang Han Yongxin Ma Wei Chen Guowu Wei Luquan Ren Key Laboratory of Bionic Engineering Ministry of EducationJilin UniversityChangchun130022People’s Republic of China Robotics Institute of NBUT Ningbo University of TechnologyNingbo315211People’s Republic of China Department of Mechanical Aerospace and Civil EngineeringThe University of ManchesterManchesterM139PLUK School of Mechanical Science and Aerospace Engineering Jilin UniversityChangchun130022People’s Republic of China School of Science Engineering and EnvironmentUniversity of SalfordSalfordM54WTUK

In this article,a new optimization system that uses few features to recognize locomotion with high classification accuracy is *** optimization system consists of three ***,the features of the mixed mechanical signal data are extracted from each analysis window of 200 ms after each foot contact ***,the Binary version of the hybrid Gray Wolf Optimization and Particle Swarm Optimization(BGWOPSO)algorithm is used to select ***,the selected features are optimized and assigned different weights by the Biogeography-Based Optimization(BBO)***,an improved K-Nearest Neighbor(KNN)classifier is employed for intention *** classifier has the advantages of high accuracy,few parameters as well as low memory *** on data from eight patients with transfemoral amputations,the optimization system is *** numerical results indicate that the proposed model can recognize nine daily locomotion modes(i.e.,low-,mid-,and fast-speed level-ground walking,ramp ascent/decent,stair ascent/descent,and sit/stand)by only seven features,with an accuracy of 96.66%±0.68%.As for real-time prediction on a powered knee prosthesis,the shortest prediction time is only 9.8 *** promising results reveal the potential of intention recognition based on the proposed system for high-level control of the prosthetic knee.

关键词： Intent recognition K-Nearest Neighbor algorithm Powered knee prosthesis Locomotion mode classification

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Thermal conductive proppant with self-suspension ability

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Petroleum Science 2023年第3期20卷 1742-1749页

作者： Guo-Qing xu xiu-Ping Lan Si-Si hao Kai-Yi Hu Si-Meng Qi Li-Dong Geng Quan xu yang Zhou Sinopec Key Laboratory of Drilling Completion and Fracturing of Shale Oil and Gas SINOPEC Research Institute of Petroleum Engineering Co.LtdBejing102249China State Key Laboratory of Petroleum Resources and Prospecting Bejing Key Laboratoryof Biogas Upgrading UtilizationHarvard SEAS-CUPB Joint Laboratory on Petroleum ScienceChina University of Petroleum(Beijing)Beijing102249China

The in situ mining technology is applied to the exploitation of medium-and low-maturity shale oil,which can use heaters to warm up the oil shale formations and pyrolyze the *** to the low thermal conductivity of oil shale,electric heaters need extra equipment to improve heat transfer *** this study,a thermally conductive proppant is fabricated by coating epoxy-resin and graphite on ceramic proppants for the first time,which could support the fracturing crack and transfer *** thermal conduction property of epoxy-resin and graphite coated proppants(EGPs)is 245%higher than that of uncoated proppants,which can transfer more heat to the oil shale formation and accelerate the conversion of *** adhesive property of EGPs is improved by 47.9%under the load force of 1500 nN,which prolongs the time for the fracture to *** summary,this novel proppant is expected to assist in-situ mining technology in the production of medium and low-maturity shale oil.

关键词： Exploitation of shaleoil In situ mining Technology Thermally conductive proppant Heat transfer

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Association of macular pigment optical density with early stage of non-proliferative diabetic retinopathy in Chinese patients with type 2 diabetes mellitus

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International Journal of Ophthalmology(English edition) 2016年第10期9卷 1433-1438页

作者： Chong-yang She Hong Gu Jun xu xiu-Fen yang xue-Tao Ren Ning-Pu Liu Beijing Tongren Eye Center Beijing Tongren HospitalCapital Medical UniversityBeijing Ophthalmology and Visual Sciences Key Laboratory Department of Ophthalmology Ningbo Medical Treatment Center Lihuili Hospital Department of Ophthalmology Beijing Friendship HospitalCapital Medical University Department of Ophthalmology Huaxin HospitalTsing Hua University

AIM：To detect the association between macular pigment optical density（MPOD）,which reflects the antioxidant ability of retina,and diabetic retinopathy（DR）and to investigate the correlated factors of ***： Totally 435 subjects of urban Chinese were recruited to the study and divided into 3 groups： non-diabetes mellitus controls（NDM）,diabetic patients without retinopathy（DWR）,and patients with early stage of non-proliferative diabetic retinopathy（DR）.Demographic and lifestyle characteristics were ascertained by questionnaire.A food-frequency questionnaire,general physical and ophthalmic examinations were completed for all *** was measured by heterochromatic flicker *** thickness was measured by optical coherence *** difference of MPOD among 3 groups was analyzed by analysis of *** correlation analyses of MPOD with the candidate influence factors were assessed using the generalized estimating equations（GEE） ***： Of the 435 participants,34 could not perform the MPOD *** analysis included 401 subjects,including 48 were in DR group,134 in DWR group,and 219 in NDM *** was not significantly different among DR（0.49 ±0.21）,DWR（0.45 ±0.21）,and NDM（0.49±0.17） groups（P=0.24） after adjustment for fasting plasma glycemia,central foveal thickness,green vegetables,Chinese wolfberry,carotene and vitamin *** all the 401 participants included,MPOD was positively associated with central foveal thickness（E=0.0007,P=0.001）,Chinese wolfberry（E=0.0345,P=0.01）,and green vegetables（E=0.0596,P〈0.001） ***： The data suggest that MPOD level is not statistically significantly influenced by the onset of diabetes or early stage of DR in the studied *** level is positively associated with thicker central foveal thickness and higher intake of foods containing carotenoids.

关键词： diabetic retinopathy diet foveal thickness macular pigment optical density

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Analysis on the motion characteristics of dynamic aircraft by dual-line-array TDI CCD optical camera

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Optoelectronics Letters 2020年第1期16卷 1-6页

作者： ZHU Lin yang xiu-bin xu Chao xu Ting-ting JIANG Li Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China University of Chinese Academy of Sciences Beijing 100049China National&Local United Engineering Research Center of Small Satellite Technology Changchun 130033China Changchun University of Science and Technology Changchun 130033China

A time-differential imaging method using a dual-line-array time delayed and integration(TDI)CCD optical camera is proposed in this paper,precisely measuring the motion parameters of the dynamic ***,based on the spat iotemporal information of the aircraft obtained by the optical satellites,the velocity on the image plane and the twice imaging time interval are *** improved scale-invariant feature transform(SIFT)algorithm that integrates the aerodynamic configuration of the aircraft is proposed to extract the region of *** that,the geometric centers of the aircraft images are determined with the median method,and then the velocity vector of the aircraft can be obtained by synthesizing a variety of spatial parameters and mathematical ***,using the snapshots of the dynamic aircraft in the area of Harbin captured by the commercial satellite JL-1,the calculated results are quite close to its actual motion characteristics,which verify our *** paper plays a guiding role in the evaluation and surveillance of dynamic aircraft.

关键词： dynamic motion characteristics

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MIXED EXCITATION IN ELECTROLUMINESENCE

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Chinese Journal of Polymer Science 2001年第6期19卷 579-583页

作者： xu-rong xu xiu-lai xu Xiao-feng Wang Xiao-hui yang Zheng xu Yan-bing Hou Institute of Optoelectronics Technology Northern Jiaotong University Beijing 100044 China No Jiaotong Univ Inst Optoelect Technol Beijing 100044 Peoples R China

Among the present three types of electric field-induced luminescence we noticed similarities between the inorganic and organic materials in electric field intensity. In this high electric field range SiO2 has three functions: acceleration, excitation and multiplication of electrons. Based on the acceleration effect, cathodoluminescence-like emission of organic molecules and polymers was found. By using the three functions of SiO2 or II-VI compounds and the heterojunction of inorganic and organic material we realized different variants of mixed excitation in electroluminescence.

关键词： cathodoluminescence-like emission mixed excitation inorganic-organic heterogeneous junction

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Wave mode computing method using the step-split Padé parabolic equation

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Chinese Physics B 2022年第9期31卷 354-361页

作者： Chuan-xiu xu Guang-Ying Zheng Hangzhou Applied Acoustics Research Institute Hangzhou 310023China Science and Technology on Sonar Laboratory Hangzhou 310023China

Models based on a parabolic equation(PE)can accurately predict sound propagation problems in range-dependent ocean ***,this method has developed rapidly in recent *** with normal mode theory,PE focuses on numerical calculation,which is difficult to use in the mode domain analysis of sound propagation,such as the calculation of mode phase velocity and group *** broaden the capability of PE models in analyzing the underwater sound field,a wave mode calculation method based on PE is proposed in this ***-split Pade PE recursive matrix equations are combined to obtain a propagation ***,the eigenvalue decomposition technique is applied to the matrix to extract sound mode eigenvalues and *** experiments on some typical waveguides are performed to test the accuracy and flexibility of the new *** on different orders of Padéapproximant demonstrate angle limitations in PE and the missing root problem is also discussed to prove the advantage of the new *** PE mode method can be expanded in the future to solve smooth wave modes in ocean waveguides,including fluctuating boundaries and sound speed profiles.

关键词： parabolic equation propagation matrix eigenvalue decomposition

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Enantiomeric Separation of Amino Alcohols by Ion-pair Chromatography

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Chinese Chemical Letters 2001年第4期12卷 355-356页

作者： Ming Hua HU xiu Zhu xu Department of Chemistry Zhejiang UniversityHangzhou 310027

Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.

关键词： Ion-pair chromatography chiral separation amino alcohols (+)-10-camphorsulphonic acid.

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Volatiles from Sophora japonica flowers attract Harmonia axyridis adults(Coleoptera: Coccinellidae)

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Journal of Integrative Agriculture 2019年第4期18卷 873-883页

作者： xiu Chun-li xu Bin PAN Hong-sheng ZHANG Wei yang Yi-zhong LU Yan-hui State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences College of Horticulture and Plant Protection Yangzhou University Lixiahe Regional Institute of Agricultural Sciences of Jiangsu Institute of Plant Protection Xinjiang Academy of Agricultural Sciences

The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. In a field investigation, we found that H. axyridis adults preferred S. japonica during its flowering period even though their optimal prey(aphid) is absent at this time. In addition, male and female adults were attracted to S. japonica flowers to a similar extent in a Y-tube olfactometer assay. Using coupled gas chromatography-electroantennogram detection(GC-EAD), we identified a flower odor component(nonanal) that elicited a significant electrophysiological response in H. axyridis. Electroantennogram(EAG) dose-dependent responses revealed that the amplitude of the adult beetle's EAG response increased with increasing concentration of nonanal, peaking at 10 mg mL^(–1). In Y-tube olfactometer behavioral tests, H. axyridis adults preferred a 10 mg mL^(–1) nonanal source over a 100 mg mL^(–1) diluent. Under field conditions, the adults were significantly attracted to both concentrations(10 and 100 mg mL^(–1)), and high concentrations generally had greater attraction. All these results suggest that nonanal, a volatile compound of S. japonica flowers, greatly attracts H. axyridis adults. This study provides a basis for the development of synthetic attractants of H. axyridis, with the potential to promote biocontrol services of this generalist predator in the native area(e.g., China) and to suppress its population by mass trapping in its invasive areas.

关键词： flower preference plant volatile electrophysiological response behavioral response attractants

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More than Scratching the Surface:Recent Progress in Brain Mechanisms Underlying Itch and Scratch

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Neuroscience Bulletin 2020年第1期36卷 85-88页

作者： xu Liu xiu-Hua Miao Tong Liu The Affiliated Zhangjiagang Hospital of Soochow University Zhangjiagang 215600China Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience Soochow UniversitySuzhou 215021China College of Life Sciences Yanan UniversityYanan 716000China

Itch(also called pruritus)is an unpleasant somatosensation that evokes a desire or reflex to scratch in humans and other mammals[1],Itch is now considered to be a unique sensory modality that is encoded by a labeled line that has genetically distinguishable neurons in the peripheral and central nervous systems[1],Acute itch evokes scratching that may help to remove potentially harmful irritants from the skin,which is believed to be evolutionarily important for *** chronic itch often occurs in patients with inflammatory skin diseases,systemic diseases,and neurological ***,chronic itch causes uncontrollable itch-scratch cycles that induce skin damage,affect sleep,and seriously reduce the quality of life[2].At present,effective treatment for chronic itch is still lacking,possibly due to limited understanding of the mechanism of itch information-processing in the nervous ***,elucidation of the molecular,cellular,and circuitry mechanisms of itch will eventually help to develop new effective strategies for the management of chronic itch.

关键词： Scratch eventually lying

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Active Disturbance Rejection Control of Hydraulic Quadruped Robots Rotary Joints for Improved Impact Resistance

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Chinese Journal of Mechanical Engineering 2024年第5期37卷 439-452页

作者： Huaizhi Zong Zhixian yang xiu Yu Junhui Zhang Jikun Ai Qixin Zhu Feng Wang Qi Su Bing xu The State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Zhejiang UniversityHangzhou 310027China China Ship Development and Design Centre Wuhan 201108China

Hydraulic actuated quadruped robots have bright application prospects and significant research values in unmanned area investigation,disaster rescue and other scenarios,due to the advantages of high payload and high power to weight *** these fields,inevitable collision of robots may occur when contact with unknown objects,step on empty objects,or collapse,all of which have an impact on the working hydraulic *** overcome the unknown external disturbances,this paper proposes an active disturbance rejection control(ADRC)strategy of double vane hydraulic rotary actuators for the hip joints of the quadruped *** the order of the valve-controlled actuator model,a three-stage tracking differentiator,a four-stage extended state observer,and a state error feedback controller are designed relatively,and the extended state observer is adopted to observe and compensate the uncertainty of external load torque of the *** effectiveness of the ADRC method is verified in simulation environment and a single joint experimental ***,the impact experiments of the limb leg unit are carried out after introducing the proposed ADRC strategy into hip joint,the limb leg unit of quadruped robots presents better impact resistance ability.

关键词： Quadruped robot Active disturbance rejection control Extended state observer Impact resistance Hydraulic rotary actuator

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