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Design method and verification of a hybrid prosthetic mechanism with energy-damper clutchable device for transfemoral amputees

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 747-764 doi: 10.1007/s11465-021-0644-4

摘要： Transfemoral amputees (TAs) have difficulty in mobility during walking, such as restricted movement of lower extremity and body instability, yet few transfemoral prostheses have explored human-like multiple motion characteristics by simple structures to fit the kinesiology, biomechanics, and stability of human lower extremity. In this work, the configurations of transfemoral prosthetic mechanism are synthesized in terms of human lower-extremity kinesiology. A hybrid transfemoral prosthetic (HTP) mechanism with multigait functions is proposed to recover the gait functions of TAs. The kinematic and mechanical performances of the designed parallel mechanism are analyzed to verify their feasibility in transfemoral prosthetic mechanism. Inspired by motion–energy coupling relationship of the knee, a wearable energy-damper clutched device that can provide energy in knee stance flexion to facilitate the leg off from the ground and can impede the leg’s swing velocity for the next stance phase is proposed. Its co-operation with the springs in the prismatic pairs enables the prosthetic mechanism to have the energy recycling ability under the gait rhythm of the knee joint. Results demonstrate that the designed HTP mechanism can replace the motion functions of the knee and ankle to realize its multimode gait and effectively decrease the peak power of actuators from 94.74 to 137.05 W while maintaining a good mechanical adaptive stability.

关键词： hybrid transfemoral prosthetic mechanism     energy recycling     wearable mechanical clutched device     mechanical adaptive stability    

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Rosin side chain type catalyst-free vitrimers with high cross-link density, mechanical strength, andthermal stability

《化学科学与工程前沿（英文）》 2023年 第17卷 第9期   页码 1267-1279 doi: 10.1007/s11705-022-2291-7

摘要： The emergence of vitrimer, a new class of polymer materials can address the problem of recyclability, reprocess ability and recyclability of thermosetting plastics. Rosin, a natural product, is an ideal raw material for the preparation of polymers in a more sustainable way. Nevertheless, due to the huge steric hindrance caused by the hydrogenated phenanthrene ring structure, the cross-link density of materials is frequently lowered. In this study, hydrogenated rosin was adopted for preparing hydrogenated rosin side-chain type diacids, which were reacted with mixed epoxy to obtain rosin side-chain type vitrimers. It was completely characterized by differential scanning calorimetry test, thermogravimetric analysis, shape memory test and self-healing test. The prepared vitrimers exhibited good self-healing properties, excellent heat resistance (Td = 352 °C) as well as high mechanical properties (tensile strength of 46.75 MPa). The tricyclic diterpene structure of rosin was introduced into the side chain in order to avoid the reduction of cross-link density resulting from the huge steric hindrance of the rigid tricyclic hydrophenylene skeleton. Vitrimers can undergo dynamic transesterification reaction without external catalysts due to the autocatalytic effect of tertiary amines from epoxy. Moreover, our work expanded the application field of rosin, increased the added value of rosin, and provided a novel method for preparing rosin-based vitrimers with ideal properties.

关键词： vitrimers     rosin     catalyst-free     high mechanical properties     dynamic transesterification reaction    

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非线性系统的自适应可拓控制器设计

翁庆昌,陈珍源

《中国工程科学》 2001年 第3卷 第7期   页码 54-58

摘要：

探讨可拓控制器的设计方法,利用自适应控制的设计策略来修正可拓控制器的增益参数,以近似获得所期望的最佳控制。所提出的控制器结构仅需调整单一参数,故易于实现。另外,引入最大值控制以保证所设计的可拓控制系统的稳定性，并将该控制器应用在非线性系统的控制上,以验证它的有效性及控制能力。

关键词： 可拓理论     自适应控制     可拓控制器     鲁棒稳定性    

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自适应多小波基函数构造与机械故障诊断应用研究

何正嘉,孙海亮,訾艳阳

《中国工程科学》 2011年 第13卷 第10期   页码 83-92

摘要：

设备在运行中萌生的故障(即早期故障)，特征信息微弱且往往被机械设备运行过程的强噪声所淹没，给故障诊断与预示带来困难，已成为国内外此领域研究的热点和难点。文章深入研究了机械故障动态信号与基函数的内积变换原理；提出了若干自适应多小波基函数构造方法；改进了几种多小波邻域区间和局部阈值降噪方法。利用典型的工程案例分析和阐述了重油催化裂化装置、连铸连轧机组、空分机、电力机车和船载卫星通信地球站传动系统在运行状态下，微弱动态信号的特征增强和复合故障特征提取的工程应用实效。

关键词： 机械故障诊断     内积变换原理     自适应基函数     多小波降噪     故障特征提取    

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Extended stochastic resonance (SR) and its applications in weak mechanical signal processing

Niaoqing HU, Min CHEN, Guojun QIN, Lurui XIA, Zhongyin PAN, Zhanhui FENG,

《机械工程前沿（英文）》 2009年 第4卷 第4期   页码 450-461 doi: 10.1007/s11465-009-0072-3

摘要： To catch symptoms of machine failure as early as possible, one of the most important strategies is to apply more progressive techniques during signal processing. This paper presents a method based on stochastic resonance (SR) to detect weak fault signal. First, a discrete model of a bistable system that can demonstrate SR is researched, and the stability condition for controlling the selection of model parameters of the discrete model and guarantee the solving convergence are established. Then, the frequency range of the weak signals that the SR model can detect is extended through a type of normalized scale transformation. Finally, the method is applied to extract the weak characteristic component from heavy noise to indicate the little crack fault in a bearing outer circle.

关键词： extended stochastic resonance (SR)     stability analysis of SR     scale transform     weak signal detection     incipient fault detection     envelope analysis    

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Polysulfone and zirconia composite separators for alkaline water electrolysis

Li XU, Wei LI, Yan YOU, Shaoxing ZHANG, Yingchun ZHAO

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 154-161 doi: 10.1007/s11705-013-1331-8

摘要： The novel composite separators composed of polysulfone and zirconia were prepared by phase inversion precipitation technique. This technique allows pre-evaporation time and extraction temperature to be varied in order to obtain optimal performances of the separators. In order to evaluate practical applicability of those composite separators, a small-scale electrolysis experimental apparatus was used to investigate the changes of cell voltage, gas purity and separator stability. The results revealed a decreased cell voltage compared to the conventional asbestos separators, and the gas purity and separator stability met the requirements for industrial use.

关键词： phase inversion     separator     alkaline water electrolysis     mechanical and chemical stability    

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三自由度混合磁轴承无模型自适应控制系统 Article

Ye YUAN, Yu-kun SUN, Qian-wen XIANG, Yong-hong HUANG, Zhi-ying ZHU

《信息与电子工程前沿（英文）》 2017年 第18卷 第12期   页码 2035-2045 doi: 10.1631/FITEE.1700324

摘要： 由于气隙磁场分布不均以及未建模动态性，数学模型不再适用于磁力轴承系统。基于错误数学模型的系统控制会表现出低响应和高颤动。为解决这一问题，本文提出一种三自由度混合磁轴承无模型自适应控制系统。该控制系统仅与控制电流和轴承的平衡位置有关。其参数估计算法的设计与模型无关，直接基于输入和输出数据的伪偏导数。本文通过不同直径的辅助轴承分析了三自由度混合磁轴承转子悬浮区域,以及通过两种不同的操作系统具体分析无模型自适应控制系统的可行性。模拟和实验结果表明，该三自由度混合磁轴承无模型自适应控制系统具有响应速度快，稳态误差小，和稳定性好等优势。

关键词： 模型自适应控制；混合磁轴承；非线性区域；快速响应；高稳定性    

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Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance reinforcements in epoxy nanocomposites

《化学科学与工程前沿（英文）》 2022年 第16卷 第4期   页码 484-497 doi: 10.1007/s11705-021-2074-6

摘要： The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process. The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method, and the morphology and lamellar structure were examined carefully. Several properties of mechanical, thermal and tribological responses of epoxy nanocomposites were performed. It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix, and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected. In addition, friction coefficient and wear rate were increased first and then decreased along with the particle content, and showed the lowest values at a mass fraction of 5%. Nevertheless, the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin (EP) nanocomposites. This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.

关键词： nickel phyllosilicate     flow-like structure     mechanical property     thermal stability     tribological performance    

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Terrain classification and adaptive locomotion for a hexapod robot Qingzhui

Yue ZHAO, Feng GAO, Qiao SUN, Yunpeng YIN

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 271-284 doi: 10.1007/s11465-020-0623-1

摘要： Legged robots have potential advantages in mobility compared with wheeled robots in outdoor environments. The knowledge of various ground properties and adaptive locomotion based on different surface materials plays an important role in improving the stability of legged robots. A terrain classification and adaptive locomotion method for a hexapod robot named Qingzhui is proposed in this paper. First, a force-based terrain classification method is suggested. Ground contact force is calculated by collecting joint torques and inertial measurement unit information. Ground substrates are classified with the feature vector extracted from the collected data using the support vector machine algorithm. Then, an adaptive locomotion on different ground properties is proposed. The dynamic alternating tripod trotting gait is developed to control the robot, and the parameters of active compliance control change with the terrain. Finally, the method is integrated on a hexapod robot and tested by real experiments. Our method is shown effective for the hexapod robot to walk on concrete, wood, grass, and foam. The strategies and experimental results can be a valuable reference for other legged robots applied in outdoor environments.

关键词： terrain classification     hexapod robot     legged robot     adaptive locomotion     gait control    

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Conservation and adaptive-reuse of historical industrial building in China in the post-industrial era

WANG Jianguo, JIANG Nan

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 474-480 doi: 10.1007/s11709-007-0064-5

摘要： The conservation and adaptive-reuse of historical industrial building is one of the most important issues to be solved in today s urban development and construction in China. In this paper, the necessity and academic meaning of the conservation and adaptive-reuse of historical industrial building were discussed by reviewing its development rend both at home and abroad, and the basic contents of the implementation of the conservation and adaptive-reuse of historical industrial building in China with specific cases provided were analyzed. It is the central task for China to put forward the restructuring and design methods, assessment principles and relevant core technical specifications based on the empirical researches on the historical industrial building and site.

关键词： historical industrial     industrial building     implementation     adaptive-reuse     empirical    

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A bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0747-1

摘要： Capacitive sensors are efficient tools for biophysical force measurement, which is essential for the exploration of cellular behavior. However, attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors. In this work, a bionic swallow structure design norm was developed for mechanical decoupling, and the influences of structural parameters on mechanical behavior were fully analyzed and optimized. A bionic feather comb distribution strategy and a portable readout circuit were proposed for eliminating electrostatic interferences. Electrostatic instability was evaluated, and electrostatic decoupling performance was verified on the basis of a novel measurement method utilizing four complementary comb arrays and application-specific integrated circuit readouts. An electrostatic pulling experiment showed that the bionic swallow structure hardly moved by 0.770 nm, and the measurement error was less than 0.009% for the area-variant sensor and 1.118% for the gap-variant sensor, which can be easily compensated in readouts. The proposed sensor also exhibited high resistance against electrostatic rotation, and the resulting measurement error dropped below 0.751%. The rotation interferences were less than 0.330 nm and (1.829 × 10−7)°, which were 35 times smaller than those of the traditional differential one. Based on the proposed bionic decoupling method, the fabricated sensor exhibited overwhelming capacitive sensitivity values of 7.078 and 1.473 pF/µm for gap-variant and area-variant devices, respectively, which were the highest among the current devices. High immunity to mechanical disturbances was maintained simultaneously, i.e., less than 0.369% and 0.058% of the sensor outputs for the gap-variant and area-variant devices, respectively, indicating its great performance improvements over existing devices and feasibility in ultralow biomedical force measurement.

关键词： micro-electro-mechanical system capacitive sensor     bionics     operation instability     mechanical and electrical decoupling     biomedical force measurement    

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Synthesis and characterization of biodegradable thermoplastic elastomers derived from N′,N-bis (2-carboxyethyl)-pyromellitimide, poly(butylene succinate) and polyethylene glycol

Jiaojiao Shang, Guo Yao, Ronghui Guo, Wei Zheng, Long Gu, Jianwu Lan

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 457-466 doi: 10.1007/s11705-018-1716-9

摘要：

Biodegradable poly(ether-imide-ester) elastomers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N′,N-bis(2-carboxyethyl)-pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystallinities, thermal stabilities, mechanical properties, hydrophilicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly(ether-ester) exhibited monoclinic chain packing. Increasing the amount of aromatic bisimide moieties in the poly(ether-ester) reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly(ether-ester) backbones endowed the elastomers with improved biodegradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.

关键词： thermoplastic elastomers     biodegradability     thermo-stability     mechanical property     aromatic bisimide moiety    

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Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

《化学科学与工程前沿（英文）》 2017年 第11卷 第2期   页码 220-230 doi: 10.1007/s11705-017-1624-4

摘要： Clindamycin phosphate (CP), an antibacterial agent, has been reported to form several solid-state forms. The crystal structures of two CP solvates, a dimethyl sulfoxide (DMSO) solvate and a methanol/water solvate (solvate V), have been determined by single crystal X-ray diffraction. The properties and transformations of these forms were characterized by powder X-ray diffraction, Single-crystal X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, hot-stage microscopy, and dynamic vapor sorption. Very different hydrogen bonding networks exist among the host-host and host-solvent molecules in the two crystal structures, resulting in different moisture stabilities. The thermal stabilities of the two solvates upon heating and desolvation were also studied. When the temperature was above the boiling point of methanol, solvate V converted to a polymorphic phase after a one step desolvation process, whereas the desolvation temperature of the DMSO solvate was below the boiling point of DMSO. At the relative humidity above 43%, the DMSO solvate transformed to a hydrate at 25 °C. In contrast, solvate V did not transform at any of the humidities studied.

关键词： clindamycin phosphate     solvate     crystal structure     thermal stability     moisture stability    

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An adaptive sliding mode control technology for weld seam tracking

Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE

《机械工程前沿（英文）》 2015年 第10卷 第1期   页码 95-101 doi: 10.1007/s11465-015-0332-3

摘要：

A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.

关键词： weld seam tracking     welding robotic manipulator     adaptive control     sliding mode control    

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Determination of mechanical parameters for elements in meso-mechanical models of concrete

Xianglin GU, Junyu JIA, Zhuolin WANG, Li HONG, Feng LIN

《结构与土木工程前沿（英文）》 2013年 第7卷 第4期   页码 391-401 doi: 10.1007/s11709-013-0225-7

摘要： The responses of cement mortar specimens of different dimensions under compression and tension were calculated based on the discrete element method with the modified-rigid-body-spring concrete model, in which the mechanical parameters derived from macro-scale material tests were applied directly to the mortar elements. By comparing the calculated results with those predicted by the Carpinteri and Weibull size effects laws, a series of formulas to convert the macro-scale mechanical parameters of mortar and interface to those at the meso-scale were proposed through a fitting analysis. Based on the proposed formulas, numerical simulation of axial compressive and tensile failure processes of concrete and cement mortar materials, respectively were conducted. The calculated results were a good match with the test results.

关键词： concrete     meso-mechanical model     discrete element method     size effect     mechanical parameter    

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标题 作者 时间 类型 操作

Design method and verification of a hybrid prosthetic mechanism with energy-damper clutchable device for transfemoral amputees

期刊论文

Rosin side chain type catalyst-free vitrimers with high cross-link density, mechanical strength, andthermal stability

期刊论文

非线性系统的自适应可拓控制器设计

翁庆昌,陈珍源

期刊论文

自适应多小波基函数构造与机械故障诊断应用研究

何正嘉,孙海亮,訾艳阳

期刊论文

Extended stochastic resonance (SR) and its applications in weak mechanical signal processing

Niaoqing HU, Min CHEN, Guojun QIN, Lurui XIA, Zhongyin PAN, Zhanhui FENG,

期刊论文

Polysulfone and zirconia composite separators for alkaline water electrolysis

Li XU, Wei LI, Yan YOU, Shaoxing ZHANG, Yingchun ZHAO

期刊论文

三自由度混合磁轴承无模型自适应控制系统

Ye YUAN, Yu-kun SUN, Qian-wen XIANG, Yong-hong HUANG, Zhi-ying ZHU

期刊论文

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance reinforcements in epoxy nanocomposites

期刊论文

Terrain classification and adaptive locomotion for a hexapod robot Qingzhui

Yue ZHAO, Feng GAO, Qiao SUN, Yunpeng YIN

期刊论文

Conservation and adaptive-reuse of historical industrial building in China in the post-industrial era

WANG Jianguo, JIANG Nan

期刊论文

A bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow

期刊论文

Synthesis and characterization of biodegradable thermoplastic elastomers derived from N′,N-bis (2-carboxyethyl)-pyromellitimide, poly(butylene succinate) and polyethylene glycol

Jiaojiao Shang, Guo Yao, Ronghui Guo, Wei Zheng, Long Gu, Jianwu Lan

期刊论文

Solvates and polymorphs of clindamycin phosphate: Structural, thermal stability and moisture stability

Junbo Gong, Dejiang Zhang, Yuanyuan Ran, Keke Zhang, Shichao Du

期刊论文

An adaptive sliding mode control technology for weld seam tracking

Jie LIU,Youmin HU,Bo WU,Kaibo ZHOU,Mingfeng GE

期刊论文

Determination of mechanical parameters for elements in meso-mechanical models of concrete

Xianglin GU, Junyu JIA, Zhuolin WANG, Li HONG, Feng LIN

期刊论文