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Dimensional synthesis of a novel 5-DOF reconfigurable hybrid perfusion manipulator for large-scale spherical

Hui YANG, Hairong FANG, Yuefa FANG, Xiangyun LI

《机械工程前沿（英文）》 2021年 第16卷 第1期   页码 46-60 doi: 10.1007/s11465-020-0606-2

摘要： A novel hybrid perfusion manipulator (HPM) with five degrees of freedom (DOFs) is introduced by combining the 5PUS-PRPU (P, R, U and S represent prismatic, revolute, universal and spherical joint, respectively) parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer. This study mainly presents the dimensional synthesis of the proposed HPM. First, the inverse kinematics, including the analytic expression of the rotation angles of the U joint in the PUS limb, is obtained, and mobility analysis is conducted based on screw theory. The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function. Second, a global and comprehensive objective function (GCOF) is proposed to represent the Jacobian matrix’s condition number. With the genetic algorithm, dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints. The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained. Lastly, the optimal structure parameters of the proposed 5-DOF HPM are determined. Results show that the HPM with the optimized parameters has an enlarged orientation workspace, and the maximum angle of the reconfigurable base is decreased, which is conducive to improving the overall stiffness of HPM.

关键词： 5-DOF hybrid manipulator     reconfigurable base     large workspace     dimensional synthesis     optimal design    

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Kinematical synthesis of an inversion of the double linked fourbar for morphing wing applications

J. AGUIRREBEITIA, R. AVILéS, I. FERNáNDEZ, M. ABASOLO

《机械工程前沿（英文）》 2013年 第8卷 第1期   页码 17-32 doi: 10.1007/s11465-013-0364-5

摘要：

This paper presents the kinematical features of an inversion of the double linked fourbar for morphing wing purposes. The structure of the mechanism is obtained using structural synthesis concepts, from an initial conceptual schematic. Then, kinematic characteristics as instant center of rotation, lock positions, dead point positions and uncertainty positions are derived for this mechanism in order to face the last step, the dimensional synthesis; in this sense, two kinds of dimensional synthesis are arranged to guide the wing along two positions, and to fulfill with the second one some aerodynamic and minimum actuation energy related issues.

关键词： morphing wing     structural synthesis     dimensional synthesis     geometrical kinematics    

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Shape/size controlling syntheses, properties and applications of two-dimensional noble metal nanocrystals

Baozhen An,Mingjie Li,Jialin Wang,Chaoxu Li

《化学科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 360-382 doi: 10.1007/s11705-016-1576-0

摘要： Two dimensional (2D) nanocrystals of noble metals (e.g., Au, Ag, Pt) often have unique structural and environmental properties which make them useful for applications in electronics, optics, sensors and biomedicines. In recent years, there has been a focus on discovering the fundamental mechanisms which govern the synthesis of the diverse geometries of these 2D metal nanocrystals (e.g., shapes, thickness, and lateral sizes). This has resulted in being able to better control the properties of these 2D structures for specific applications. In this review, a brief historical survey of the intrinsic anisotropic properties and quantum size effects of 2D noble metal nanocrystals is given and then a summary of synthetic approaches to control their shapes and sizes is presented. The unique properties and fascinating applications of these nanocrystals are also discussed.

关键词： two-dimension     noble metal     nanocrystal     surface plasmon     controllable synthesis    

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Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 217-221 doi: 10.1007/s11709-007-0026-y

摘要： It is usually difficult to determine the actual safety factors of rock masses in an ordinary two-dimensional stability analysis if the safety factors of the different cross sections in the rock mass vary significantly. In addition to the actual slope, arch dam abutment, and the actual foundation of a high building, another example is that the different cross sections of the foundation in the monolith of a gravity dam vary significantly, just like the condition at the overflow dam in the Baise project. A three-dimensional stability analysis method based on the upper-bound theorem was employed to solve this problem. The parameters used in the analysis were obtained from geomechanics tests, as well as continuity simulations of the randomly distributed joints. Two failure patterns against sliding are analyzed. One pattern is the foundation slide along deep-seated planes which were determined by calculations. The other pattern is the foundation slide along the planes across the bottom of the high steps in the foundation pit. The results indicate that a special overflow dam monolith can be considered to be safe in case of considering the three dimensional effect. However, a key wall with a depth of 5m must be constructed at the upper side of this monolith in order to ensure the safety of the foundation.

关键词： ordinary two-dimensional     randomly     monolith     three-dimensional stability     different    

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A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0688-0

摘要： The use of artificial intelligence to process sensor data and predict the dimensional accuracy of machined parts is of great interest to the manufacturing community and can facilitate the intelligent production of many key engineering components. In this study, we develop a predictive model of the dimensional accuracy for precision milling of thin-walled structural components. The aim is to classify three typical features of a structural component—squares, slots, and holes—into various categories based on their dimensional errors (i.e., “high precision,” “pass,” and “unqualified”). Two different types of classification schemes have been considered in this study: those that perform feature extraction by using the convolutional neural networks and those based on an explicit feature extraction procedure. The classification accuracy of the popular machine learning methods has been evaluated in comparison with the proposed deep learning model. Based on the experimental data collected during the milling experiments, the proposed model proved to be capable of predicting dimensional accuracy using cutting parameters (i.e., “static features”) and cutting-force data (i.e., “dynamic features”). The average classification accuracy obtained using the proposed deep learning model was 9.55% higher than the best machine learning algorithm considered in this paper. Moreover, the robustness of the hybrid model has been studied by considering the white Gaussian and coherent noises. Hence, the proposed hybrid model provides an efficient way of fusing different sources of process data and can be adopted for prediction of the machining quality in noisy environments.

关键词： precision milling     dimensional accuracy     cutting force     convolutional neural networks     coherent noise    

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Electronic and mechanical responses of two-dimensional HfS

Mohammad SALAVATI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 486-494 doi: 10.1007/s11709-018-0491-5

摘要： During the last decade, numerous high-quality two-dimensional (2D) materials with semiconducting electronic character have been synthesized. Recent experimental study (Sci. Adv. 2017;3: e1700481) nevertheless confirmed that 2D ZrSe and HfSe are among the best candidates to replace the silicon in nanoelectronics owing to their moderate band-gap. We accordingly conducted first-principles calculations to explore the mechanical and electronic responses of not only ZrSe and HfSe , but also ZrS and HfS in their single-layer and free-standing form. We particularly studied the possibility of engineering of the electronic properties of these attractive 2D materials using the biaxial or uniaxial tensile loadings. The comprehensive insight provided concerning the intrinsic properties of HfS , HfSe , ZrS , and ZrSe can be useful for their future applications in nanodevices.

关键词： 2D materials     mechanical     electronic     DFT    

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A dimensional analysis on asphalt binder fracture and fatigue cracking

Qian ZHAO, Zhoujing YE

《结构与土木工程前沿（英文）》 2018年 第12卷 第2期   页码 201-206 doi: 10.1007/s11709-017-0402-1

摘要： Fracture and fatigue cracking in asphalt binder are two of most serious problems for pavement engineers. In this paper, we present a new comprehensive approach, which consists both of dimensional analysis using Buckingham Theorem and -integral analysis based on classic fracture mechanics, to evaluate the fracture and fatigue on asphalt binder. It is discovered that the dimensional analysis could provide a new perspective to analyze the asphalt fracture and fatigue cracking mechanism.

关键词： Dimensional analysis     asphalt     fracture     fatigue cracking    

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Automated synthesis of steady-state continuous processes using reinforcement learning

《化学科学与工程前沿（英文）》 2022年 第16卷 第2期   页码 288-302 doi: 10.1007/s11705-021-2055-9

摘要： Automated flowsheet synthesis is an important field in computer-aided process engineering. The present work demonstrates how reinforcement learning can be used for automated flowsheet synthesis without any heuristics or prior knowledge of conceptual design. The environment consists of a steady-state flowsheet simulator that contains all physical knowledge. An agent is trained to take discrete actions and sequentially build up flowsheets that solve a given process problem. A novel method named SynGameZero is developed to ensure good exploration schemes in the complex problem. Therein, flowsheet synthesis is modelled as a game of two competing players. The agent plays this game against itself during training and consists of an artificial neural network and a tree search for forward planning. The method is applied successfully to a reaction-distillation process in a quaternary system.

关键词： automated process synthesis     flowsheet synthesis     artificial intelligence     machine learning     reinforcement learning    

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Inner strain determination of three-dimensional braided preforms with co-braided optical fiber sensors

LI Xianghua, LIU Xiaohui, YUAN Shenfang

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 416-420 doi: 10.1007/s11465-008-0062-x

摘要： The experimental characterization of three-dimensional (3-D) braided composites is extremely important for their design and analysis. Because of their desirable attributes and outstanding performance, optical fiber sensors (OFSs) can be embedded to monitor mechanical properties of textile composites. This paper discusses two techniques to incorporate different OFSs into 3-D braided composite preforms. The operating principle of various sensor systems is first conducted. Experiments using Michelson interferometers, FBG sensors, and micro-bend sensors are performed to verify the concept of the proposed method. Strain curves of various OFSs tests are finally compared, and they all exhibit good linearity.

关键词： different     experimental characterization     three-dimensional     composite     micro-bend    

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Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row

JIANG Jian, LIU Bo, WANG Yangang, NAN Xiangyi

《能源前沿（英文）》 2008年 第2卷 第3期   页码 320-325 doi: 10.1007/s11708-008-0041-2

摘要： Numerical simulation of three-dimensional turbulent flow in a multistage axial compressor blade row is conducted. A high resolution, third-order ENN scheme is adopted to catch the shockwave and simulate the turbulent flow correctly,

关键词： simulation     compressor     multistage     third-order     three-dimensional turbulent    

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Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 350-367 doi: 10.1007/s11709-022-0923-0

摘要： A new rocking constraint device (RCD) is developed for three-dimensional (3D) base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion, and rocking constraint capacity when the superstructure is susceptible to rocking. Theoretical formulas for calculating the damping and rocking constraint stiffness of the RCD are proposed. Two series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the RCD. The test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component, and that the RCD can effectively suppress rocking. Although the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency, the average vertical stiffness of the two cylinders, which determines the rocking constraint stiffness of the RCD, is independent of the two factors. Comparisons of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9% and 11.0%, respectively.

关键词： three-dimensional isolation     rocking behavior     rocking constraint device     replaceable damping component     sinusoidal test    

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Interlayer-confined two-dimensional manganese oxide-carbon nanotube catalytic ozonation membrane for

《化学科学与工程前沿（英文）》 2022年 第16卷 第5期   页码 731-744 doi: 10.1007/s11705-021-2110-6

摘要： Catalytic ozonation technology has attracted copious attention in water purification owing to its favorable oxidative degradation of pollutants and mitigation of membrane fouling capacity. However, its extensive industrial application has been restricted by the low ozone utilization and limited mass transfer of the short-lived radical species. Interlayer space-confined catalysis has been theoretically proven to be a viable strategy for achieving high catalytic efficiency. Here, a two-dimensional MnO2-incorporated ceramic membrane with tunable interspacing, which was obtained via the intercalation of a carbon nanotube, was designed as a catalytic ozonation membrane reactor for degrading methylene blue. Benefiting from the abundant catalytic active sites on the surface of two-dimensional MnO2 as well as the ultralow mass transfer resistance of fluids due to the nanolayer confinement, an excellent mineralization effect, i.e., 1.2 mg O3(aq) mg–1 TOC removal (a total organic carbon removal rate of 71.5%), was achieved within a hydraulic retention time of 0.045 s of pollutant degradation. Further, the effects of hydraulic retention time and interlayer spacing on methylene blue removal were investigated. Moreover, the mechanism of the catalytic ozonation employing catalytic ozonation membrane was proposed based on the contribution of the Mn(III/IV) redox pair to electron transfer to generate the reactive oxygen species. This innovative two-dimensional confinement catalytic ozonation membrane could act as a nanoreactor and separator to efficiently oxidize organic pollutants and enhance the control of membrane fouling during water purification.

关键词： catalytic membrane reactor     catalytic ozonation     nanoconfinement     two-dimensional manganese oxide    

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Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

《能源前沿（英文）》 2023年 第17卷 第5期   页码 569-584 doi: 10.1007/s11708-023-0875-7

摘要： Lithium (Li) metal is believed to be the “Holy Grail” among all anode materials for next-generation Li-based batteries due to its high theoretical specific capacity (3860 mAh/g) and lowest redox potential (−3.04 V). Disappointingly, uncontrolled dendrite formation and “hostless” deposition impede its further development. It is well accepted that the construction of three-dimensional (3D) composite Li metal anode could tackle the above problems to some extent by reducing local current density and maintaining electrode volume during cycling. However, most strategies to build 3D composite Li metal anode require either electrodeposition or melt-infusion process. In spite of their effectiveness, these procedures bring multiple complex processing steps, high temperature, and harsh experimental conditions which cannot meet the actual production demand in consideration of cost and safety. Under this condition, a novel method to construct 3D composite anode via simple mechanical modification has been recently proposed which does not involve harsh conditions, fussy procedures, or fancy equipment. In this mini review, a systematic and in-depth investigation of this mechanical deformation technique to build 3D composite Li metal anode is provided. First, by summarizing a number of recent studies, different mechanical modification approaches are classified clearly according to their specific procedures. Then, the effect of each individual mechanical modification approach and its working mechanisms is reviewed. Afterwards, the merits and limits of different approaches are compared. Finally, a general summary and perspective on construction strategies for next-generation 3D composite Li anode are presented.

关键词： lithium (Li)-ion battery (LIB)     Li metal battery     three-dimensional (3D) composite Li metal anode     mechanical modification     reducing local current density    

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Three-dimensional modeling of borehole data cored from engineering rock mass

HE Manchao, LI Xueyuan, LIU Bin, XU Nengxiong

《结构与土木工程前沿（英文）》 2007年 第1卷 第3期   页码 334-339 doi: 10.1007/s11709-007-0044-9

摘要： Vast data from the drilling and geophysical prospecting are reliable original information to describe the space state of engineering rock mass, and one of the main difficulties in three-dimensional (3D) modeling of engineering rock mass is the processing of the primary data. From the viewpoint of 3D modeling, the engineering rock masses are classified as four basic types according to their geometric characteristics of geologic structure: (1) continuum rock mass; (2) discontinuous rock mass; (3) overturned fold rock mass and (4) intrusive rock mass. Because drilling data are very important to describe the characters of multi-scale of the spatial data for rock mass, the rule of how to process drilling data is developed to help appropriately display them in the viewpoint of 3D space. According to the characteristics of rock mass layers, the processing method of drilling data for 3D modeling of engineering rock masses, along with the layer thicknesses, is also proposed, including the evaluation rules and the extensive direction for original borehole data. By this method, the typical 3D data modeled is completed and the model form of the engineering rock mass is developed. By this example, it is finally verified that the method presented is successful and feasible to process 3D engineering rock mass.

关键词： three-dimensional     discontinuous     primary     extensive direction     engineering    

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Stability of three-dimensional printable foam concrete as function of surfactant characteristics

《结构与土木工程前沿（英文）》   页码 935-947 doi: 10.1007/s11709-023-0964-z

摘要： Extrudability is one of the most critical factors when designing three-dimensional printable foam concrete. The extrusion process likely affects the foam stability which necessitates the investigation into surfactant properties particularly for concrete mixes with high foam contents. Although many studies have been conducted on traditional foam concrete in this context, studies on three-dimensional printed foam concrete are scarce. To address this research gap, the effects of surfactant characteristics on the stability, extrudability, and buildability of three-dimensional printed foam concrete mixes with two design densities (1000 and 1300 kg/m3) using two different surfactants and stabilizers (synthetic-based sodium lauryl sulfate stabilized with carboxymethyl cellulose sodium salt, and natural-based hingot surfactant stabilized with xanthan gum) were investigated in this study. Fresh density tests were conducted before and after the extrusion to determine stability of the foam concrete. The results were then correlated with surfactant qualities, such as viscosity and surface tension, to understand the importance of key parameters in three-dimensional printing of foam concrete. Based on the experimental results, surfactant solu1tion with viscosity exceeding 5 mPa·s and surface tension lower than 31 mN/m was recommended to yield stable three-dimensional printable foam concrete mixes. Nevertheless, the volume of foam in the mix significantly affected the printability characteristics. Unlike traditional foam concrete, the variation in the stabilizer concentration and density of concrete were found to have insignificant effect on the fresh-state-characteristics (slump, slump flow, and static yield stress) and air void microstructure of the stable mixes.

关键词： foam concrete     3D printable concrete     stability     rheology     air void microstructure    

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标题 作者 时间 类型 操作

Dimensional synthesis of a novel 5-DOF reconfigurable hybrid perfusion manipulator for large-scale spherical

Hui YANG, Hairong FANG, Yuefa FANG, Xiangyun LI

期刊论文

Kinematical synthesis of an inversion of the double linked fourbar for morphing wing applications

J. AGUIRREBEITIA, R. AVILéS, I. FERNáNDEZ, M. ABASOLO

期刊论文

Shape/size controlling syntheses, properties and applications of two-dimensional noble metal nanocrystals

Baozhen An,Mingjie Li,Jialin Wang,Chaoxu Li

期刊论文

Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

期刊论文

A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

期刊论文

Electronic and mechanical responses of two-dimensional HfS

Mohammad SALAVATI

期刊论文

A dimensional analysis on asphalt binder fracture and fatigue cracking

Qian ZHAO, Zhoujing YE

期刊论文

Automated synthesis of steady-state continuous processes using reinforcement learning

期刊论文

Inner strain determination of three-dimensional braided preforms with co-braided optical fiber sensors

LI Xianghua, LIU Xiaohui, YUAN Shenfang

期刊论文

Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row

JIANG Jian, LIU Bo, WANG Yangang, NAN Xiangyi

期刊论文

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated

期刊论文

Interlayer-confined two-dimensional manganese oxide-carbon nanotube catalytic ozonation membrane for

期刊论文

Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

期刊论文

Three-dimensional modeling of borehole data cored from engineering rock mass

HE Manchao, LI Xueyuan, LIU Bin, XU Nengxiong

期刊论文

Stability of three-dimensional printable foam concrete as function of surfactant characteristics

期刊论文