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Amorphous hybrid tungsten oxide–nickel hydroxide nanosheets used as a highly efficient electrocatalyst for hydrogen evolution reaction

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Nano Research 2024年第4期17卷 2499-2508页

作者： Chao Lyu Chenghai Dai yiwei Tan State Key Laboratory of Materials-Oriented Chemical Engineering School of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing 211816China

There are more challenges for alkaline hydrogen evolution reaction(HER)via simultaneously expediting the electron-coupled water dissociation process(Volmer step)and the following electrochemical H_(2) desorption(Heyrovsky step).Hybrid amorphous electrocatalysts are highly desirable for efficient hydrogen evolution from water-alkali electrolyzers due to the bifunctionality for the different elementary steps of HER and optimal interactions with water molecules and the reactive hydrogen intermediates(Had).Herein,the synthesis of amorphous hybrid ultrathin(tungsten oxide/nickel hydroxide)hydrate(a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O)nanosheets on nickel foam(NF)for efficient alkaline HER is *** structural and composition features of a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O are characterized in *** resulting a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O/NF electrocatalyst with the synergistic effect of both hybrid components for the HER elementary steps shows greatly improved the activity and durability for the HER with a low overpotential of-41 and-163 mV at-10 and-500 mA·cm^(-2),respectively,a Tafel slope as low as-72.9 mV·dec^(-1),and long-term stability of continuous electrolysis for at least 150 h accompanying by inappreciable overpotential change in 1 M *** the hybrid a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O,Ni(OH)_(2) and WO_(3) moieties are separately responsible for accelerating dissociative adsorption of water and weakening Had adsorption strength,which is beneficial to the improvement of the alkaline HER activity.

关键词： amorphous nanomaterial bimetallic electrocatalyst tungsten oxide ultrathin nanosheet hydrogen evolution reaction

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Parameter estimation of the structured illumination pattern based on principal component analysis (PCA): PCA-SIM

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Light(Science & Applications) 2023年第2期12卷 150-152页

作者： Xin Chen yiwei Hou Peng Xi Department of Biomedical Engineering College of Future TechnologyPeking University100871 BeijingChina National Biomedical Imaging Center Peking University100871 BejingChina

Principal component analysis(PCA),a common dimensionality reduction method,is introduced into SIM to identify the frequency vectors and pattern phases of the illumination pattern with precise subpixel accuracy,fast sp... 详细信息

关键词： pattern illumination component

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Is uncertainty always bad for the performance of transportation systems?

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Communications in Transportation Research 2021年第1期1卷 176-181页

作者： Wei Wang yiwei Wu Department of Logistics and Maritime Studies The Hong Kong Polytechnic UniversityHong KongChina

Uncertainty is usually perceived as having negative effects on transportation systems,such as increasing operation cost,decreasing resource utility,and reducing customer ***,it is unclear whether this perception is universally true or is true only under certain *** research compares the performance of transportation systems with uncertain parameters with the performance of the same systems in which the uncertain parameters are replaced by their *** analyses prove that uncertainty can have negative,negligible,and positive impact on the performance of transportation systems under different conditions.

关键词： Impact of uncertainty Transportation system Stochastic models

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考虑双线相互干涉的铁路项目施工组织研究

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山东理工大学学报（自然科学版） 2025年第1期39卷 52-59页

作者：周亦威杨烁郭锴上海理工大学管理学院上海200093 上海理工大学智慧应急管理学院上海200093

针对线状活动铁路工程施工场景,在双线相互干涉条件下,基于线性计划方法,对双线的空间表达以施工区段为单位进行重构,建立时间-施工区段模型,考虑时间、空间、施工资源等约束,构建线路内部约束条件,再以线路内部约束为基础,建立线路间... 详细信息

针对线状活动铁路工程施工场景,在双线相互干涉条件下,基于线性计划方法,对双线的空间表达以施工区段为单位进行重构,建立时间-施工区段模型,考虑时间、空间、施工资源等约束,构建线路内部约束条件,再以线路内部约束为基础,建立线路间约束条件。结合标准遗传算法,以各条线路各区段内施工资源配置情况为自变量,构建双线相互干涉条件下铁路工程施工进度计划工期优化算法,能够在算法中自动输出最优工期条件下的资源配置情况,根据算法输出的最优工期和资源配置情况制作对应的线性计划图。算例仿真结果表明,工期优化模型和算法能够高效获得最短工期下双线相互干涉的铁路项目施工进度计划,验证了本文模型的合理性和算法的有效性。

关键词：铁路施工进度管理线性计划方法遗传算法双线相互干涉

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Carbonate Ontology and Its Application for Integrating Microfacies Data

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Journal of Earth Science 2023年第5期34卷 1328-1338页

作者： yiwei Xu Xiumian Hu Zhong Han State Key Laboratory of Paleobiology and Stratigraphy Nanjing Institute of Geology and PaleontologyChinese Academy of SciencesNanjing 210008China State Key Laboratory of Mineral Deposit Research School of Earth Sciences and Engineering.Nanjing UniversityNanjing 210023China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Institute of Sedimentary GeologyChengdu University of TechnologyChengdu 610059China

Carbonate rocks record essential information on changes in paleoclimate and paleoceanography. Abundant geological and geochemical data of carbonate rocks have been accumulated over the past decades;however, most of the data are stored in the published literature with highly unstructured forms, and are thus difficult to reuse. The ontology is a standard knowledge model for data integration, which can promote data storage and reutilization. This study proposes a carbonate ontology that represents the concepts in carbonate microfacies. The carbonate ontology constructed by the top-down process contains 215 terms of classifications and petrographic descriptions of carbonate rocks. Furthermore, carbonate microfacies of the Cretaceous(Aptian) carbonate platform in the Betic Cordillera and Jurassic carbonate platform in Tibet provide the data from case studies for the testing and initial validation of the proposed ontology. The carbonate ontology is under continuous expansion following the bottom-up approach and open access on the website of the deep-time digital Earth(DDE) program.

关键词： ontology carbonate rock carbonate petrography microfacies heterogeneous termino logy DDE knowledge graph

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Micromechanical testing and property upscaling of planetary rocks:A critical review

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International Journal of Mining Science and Technology 2024年第9期34卷 1217-1241页

作者： yiwei Liu Guoping Zhang Jiangmei Qiao Xuhai Tang School of Civil Engineering Wuhan UniversityWuhan 430072China Wuhan University Shenzhen Research Institute Shenzhen 518108China Department of Civil and Environmental Engineering University of Massachusetts AmherstAmherstMA 01003USA

Knowledge of the mechanical behavior of planetary rocks is indispensable for space *** scarcity of pristine samples and the irregular shapes of planetary meteorites make it difficult to obtain representative samples for conventional macroscale rock mechanics experiments(macro-RMEs).This critical review discusses recent advances in microscale RMEs(micro-RMEs)techniques and the upscaling methods for extracting mechanical *** of mineralogical and microstructural analyses,along with non-destructive mechanical techniques,have provided new opportunities for studying planetary rocks with unprecedented precision and ***,we summarize several mainstream methods for obtaining the mineralogy and microstructure of planetary ***,nondestructive micromechanical testing methods,nanoindentation and atomic force microscopy(AFM),are detailed reviewed,illustrating the principles,advantages,influencing factors,and available testing results from ***,several feasible upscaling methods that bridge the micro-measurements of meteorite pieces to the strength of the intact body are ***,the potential applications of planetary rock mechanics research to guiding the design and execution of space missions are environed,ranging from sample return missions and planetary defense to extraterrestrial *** discussions are expected to broaden the understanding of the microscale mechanical properties of planetary rocks and their significant role in deep space exploration.

关键词： Meteorites Planetary rock mechanics Non-destructive testing Upscaling method Extraterrestrial construction Space exploration

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Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

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Frontiers of Mechanical Engineering 2021年第4期16卷 711-725页

作者： yiwei LIU Shipeng CUI Yongjun SUN State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

The safety of human-robot interaction is an essential requirement for designing collaborative ***,this paper aims to design a novel variable stiffiiess actuator(VSA)that can provide safer physical human-robot interaction for collaborative *** A follows the idea of modular design,mainly including a variable stiffiiess module and a drive *** variable stiffiiess module transmits the motion from the drive module in a roundabout maimer,making the modularization of VS A *** the key component of the variable stiffiiess module,a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously,which can eliminate the additional bending moment caused by the asymmetric *** design of the doubledeck grooves in the lever allows the pivot to move freely in the groove,avoiding the geometric constraint between the ***,the VSA stiffiiess can change from zero to infinity as the pivot moves from one end of the groove to the *** facilitate building a manipulator in the future,an expandable electrical system with a distributed structure is also *** calibration and control experiments are performed to evaluate the physical performance of the designed *** results show that the VSA stiffiiess is close to the theoretical design ***,the VSA with a proportional-derivative feedback plus feedforward controller exhibits a fast response for stiffiiess regulation and a good performance for position tracking.

关键词： variable stiffiiess actuator variable stiffness module drive module symmetrical structure doubledeck grooves expandable electrical system

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Dynamic modeling and analysis of the 3-PRS power head based on the screw theory and rigid multipoint constraints

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Science China(Technological Sciences) 2023年第7期66卷 1869-1882页

作者： MA yiwei TIAN YanLing LIU XianPing LU ChengHao School of Engineering The University of WarwickCoventryCV47ALUK School of Mechanical Engineering Tianjin UniversityTianjin300072China

This study presents a dynamic modeling and analysis methodology for the 3-PRS parallel ***,an improved reduced dynamic model of component substructures is proposed using the dynamic condensation technique and the rigid multipoint constraints at the joint/interface level,leading to a minimum set of generalized coordinates for external ***,the mapping between interface constraint stiffness and global stiffness is illustrated,resulting in an analytical stiffness model of joint ***,the derived component and joint substructures are synthesized into the entire mechanism based on the Lagrange ***,a case study illustrates that the lower-order dynamic performances predicted within the proposed approach have the same trend as those obtained from a complete-order finite element *** root mean square discrepancy of the lower-order natural frequencies between the two models is less than 5.92%,indicating the accuracy and effectiveness of the proposed *** developed approach can highly and efficiently predict the dynamic performance distributions across the entire workspace and guide the optimal functional design under the virtual machine framework.

关键词： dynamic modeling parallel kinematic machines screw theory substructure synthesis rigid multipoint constraints

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Design Schemes and Comparison Research of the End-effector of Large Space Manipulator

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 674-687页

作者： FENG Fei LIU yiwei LIU Hong CAI Hegao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150080 China

The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on ***,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical *** to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are *** the end-effector should accommodate the following misalignments of the mechanical *** translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,*** end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed *** three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in *** capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS *** results show that the misalignment tolerance capabilities of these two schemes could satisfy the *** the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,*** the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals *** end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and t

关键词： end-effector large space manipulator docking mechanism soft capture misalignment tolerance passive compliance active compliance

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The Morphology and Reciprocation Movement of Honeybee＇s Hairy Tongue for Nectar Uptake

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Journal of Bionic Engineering 2016年第1期13卷 98-107页

作者： yiwei Zhao Jianing Wu Heng Yang Shaoze Yan Division of Intelligent and Biomeehanical Systems State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University Beijing 100084 China Department of Automotive Engineering Tsinghua University Beijing 100084 China

A honeybee uses its brush-like tongue （glossa） to dip nectar and the setae densely distributed on it can increase the amount of trapped nectar observably. The glossa is often simplified as a cylinder covered by uniformly distributed and vertically erected setae during the drinking process, herein variations of the dimensions together with the erection angles of glossal setae are assumed to be negligible. In this paper, a dynamic model for the glossa retraction phase under the specific erection pattern of glossal setae is established, and the energy saving mechanism is extensively studied by comparing four types of erection pat- terns. Then the theoretically-optimal configuration, which satisfies the minimum energy consumption, is achieved from the dynamic model. Using the scanning electron microscope and a specially-designed high-speed camera system, we measure the dimensions of the glossal satae and capture dynamics of the hairy glossa in nectar feeding. It is proven that the erection angle of the glossal setae varies along the tongue axis, which shows a high concordance with our theoretically-optimal configuration. Compared with the hypothetical uniform distribution mode of glossal setae proposed by former researchers, we obtain a 16% increase in energy saving from actual erection pattern.

关键词： honeybee hairy tongue glossal setae dimensional distribution erection pattern

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