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Corner Transition Toolpath Generation Based on Velocity-Blending Algorithm for Glass Edge Grinding

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Chinese Journal of Mechanical Engineering 2019年第5期32卷 50-58页

作者： Kun Ren Yujia Pan Danyan Jiang Jun Pan Wenhua Chen Xuxiao Hu College of Mechanical Engineering and Automation Zhejiang Sci-Tech University

Sharp corners usually are used on glass contours to meet the highly increasing demand for personalized products,but they result in a broken wheel center toolpath in edge *** ensure that the whole wheel center toolpath is of G1 continuity and that the grinding depth is controllable at the corners,a transition toolpath generation method based on a velocity-blending algorithm is *** the grinding depth into consideration,the sharp-corner grinding process is planned,and a velocity-blending algorithm is *** the constraints,such as traverse displacement and grinding depth,the sharp-corner transition toolpath is generated with a three-phase motion arrangement and with confirmations of the acceleration/deceleration positions.A piece of glass with three sharp corners is ground on a three-axis numerical-control glass grinding *** experimental results demonstrate that the proposed algorithm can protect the sharp corners from breakage efficiently and achieve satisfactory shape *** research proposed a toolpath generation method based on a velocity-blending algorithm for the manufacturing of personalized glass products,which generates the transition toolpath as needed around a sharp corner in real time.

关键词： Glass edge grinding Toolpath planning Velocity blending Grinding depth control

Type Synthesis of Lower Mobility Parallel Mechanisms: A Review

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 13-23页

作者： Wei Ye Qinchuan Li Faculty of Mechanical Engineering and Automation Zhejiang Sci-Tech University

Type synthesis of mechanisms aims to systematically determine all possible structures for a specific mobility requirement. Numerous methods based on di erent theories were proposed for type synthesis of lower mobility parallel mechanisms in past decades. However, there does not exist a comprehensive review on these approaches. Therefore, the goal of this paper is to give such a review, classifying the approaches proposed in the literature into three groups, namely, motion-based methods, constraint-based methods, and other methods. The motion-based methods include the Lie group based method, the GF set method, the linear transformation method, the POC set method,and the finite screw method. The constraint-based methods involve the screw theory-based method, the virtual chain method, the method based on Grassmann line geometry and line graphs, and the motion constraint generator method. Other methods contain the enumeration approach based on the general CGK mobility formula and the graph theory method. Upon thoroughly analyzing the characteristics and/or limitations of each method, this review provides a well reference to help researchers find an e ective synthesis method for innovative design and further scientific investigations for mechanisms.

关键词： Parallel mechanism Lower mobility Type synthesis Innovative design

Rhodium(Ⅱ)-Catalyzed [4+3] Cyclization of Triazoles with Indole Derivatives and Its Application in the Total Synthesis of (±)-Aurantioclavine

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Chinese Journal of Chemistry 2021年第5期39卷 1145-1152页

作者： Shengguo Duan Bing Xue Hui Meng Zihang Ye Ze-Feng Xu Chuan-Ying Li Department of Chemistry Zhejiang Sci-Tech UniversityHangzhouZhejiang 310018China

An efficient rhodium(Ⅱ)-catalyzed[4+3]cyclization reaction of 1-sulfonyl-1,2-3-triazoles and indoles was ***[5,4,3-ccflindoles,which are widely distributed in ergot alkaloids with various biological activities,could be obtained in good to excellent *** addition,the total synthesis of(±)-aurantioclavine was completed in four steps from the known compound 1a adopting this[4+3]cyclization as a key step.

关键词： Triazoles Rhodium Alkaloids Cyclization Aurantioclavine

Robust construction of minimal surface from general initial mesh

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Applied Mathematics(A Journal of Chinese universities) 2015年第2期30卷 227-244页

作者： YU Yang WU Qing-biao CHEN Min-hong Muhammad Suleman Department of Mathematics Zhejiang University Department of Mathematics Zhejiang Sci-Tech University

We analyze three commonly used energy functions in solving Plateau-Mesh Prob- lem, that is, Dirichlet, area, and the discrete mean curvature（DMC）. They all possess unique advantages compared to others, but their drawbacks restrict their usages individually. Our algo- rithm combines the three steps together to make full use of their features. At first the Dirichlet energy is optimized for faster approximation with better topology. Then the area energy is used to come close to the constrained domain. Finally the DMC energy is engaged to achieve a better converging step. Results show that our method can work under a rather noisy initial mesh, which is even topologically different from the final result.

关键词： Minimal surface variational method mesh optimization discrete mean curvature

Innovations in food waste management: from resource recovery to sustainable solutions

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WASTE DISPOSAL & SUSTAINABLE ENERGY 2024年第3期6卷 401-417页

作者： Xiao, Na Kong, Lingxian Wei, Mengmeng Hu, Xiufang Li, Ou zhejiang sci tech univ Coll Life Sci & Med 2 StQiantang Dist Hangzhou Zhejiang Peoples R China

Food waste (FW) constitutes a significant portion of municipal solid waste (MSW) and represents an underutilized resource with substantial potential for energy generation. The effective management and recycling of FW are crucial for mitigating environmental issues and minimizing associated health risks. This comprehensive review provides an in-depth overview of current technological applications for converting FW into energy with the dual goals of reducing environmental impact and maximizing resource utilization. It covers various aspects, including pretreatment methods, biological technologies (e.g., anaerobic digestion and fermentation), and thermal technologies (e.g., incineration, pyrolysis, gasification, and hydrothermal carbonization). The analysis includes the scope, advantages and disadvantages of these techniques. Landfilling, composting, and incineration are widely considered the most prevalent methods of FW disposal and have substantial negative impacts on the environment. Advanced technologies such as anaerobic fermentation offer environmental benefits and are suitable for scaling up, reducing greenhouse gas emissions, and producing renewable energy such as biogas, thus reducing carbon emissions. The promotion and adoption of advanced technologies like anaerobic fermentation can contribute to more sustainable FW management practices, reduce environmental impacts, and support the transition to a circular economy. Additionally, this article presents successful case studies, emphasizing the importance of technological integration in FW treatment. Furthermore, this article outlines future directions for FW treatment, including advancements in biological treatment technologies, decentralized treatment systems, and the adoption of digital and data-driven FW management systems. These emerging trends aim to promote sustainable, resource-efficient, and environmentally responsible FW management practices.

关键词： Food waste Biological methods Thermal methods Resource recovery Anaerobic digestion Fermentation

Mechanically Robust Polylactide Fibers with Super Heat Resistance via Constructing in situ Nanofibrils

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Chinese Journal of Polymer science 2023年第6期41卷 962-971,I0011页

作者： Jun Lu Li-Xiang Yi Yong-Huan Zhao Yang Meng Peng-Xiang Yu Juan-Juan Su Jian Han College of Materials and Textiles Zhejiang Sci-Tech UniversityHangzhou 310018China The Key Lab of Industrial Textile Material and Manufacturing technology Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China

All-PLA fibers with excellent comprehensive performance and recycling convenience are realized *** molecular weight poly(D-lactide)(HPDLA)is incorporated into poly(L-lactide)(PLLA)matrix to construct in situ nanofibrils structure by taking advantages of the microphase separation between HPDLA and *** tensile strength of HPDLA/PLLA composite fibers(HDL-8)is enhanced from 2.1 cN/dtex of neat PLLA-8 fibers up to 2.9 cN/*** boiling water shrinkage(BWS)and shrinkage in hot air(HAS)significantly decrease to 7.8%and 2.8%,*** abundance of in situ nanofibrils creates a grille-like structure that is crucial for both heat and hydrolysis *** strikingly,a hybrid shish-kebab structure induced by the in situ nanofibrils serves as a mechanical *** work paves a new way for heat resistance and self-reinforcement modification of PLA materials.

关键词： materials. fibers lactide

Design of Vegetable Pot Seedling Pick‑up Mechanism with Planetary Gear Train

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 87-97页

作者： Zhipeng Tong Gaohong Yu Xiong Zhao Pengfei Liu Bingliang Ye zhejiang Province Key Laboratory of Transplanting Equipment and technology Zhejiang Sci-Tech UniversityHangzhou 310018China Faculty of Mechanical Engineering&Automation Zhejiang Sci-Tech UniversityHangzhou 310018China

It has been challenging to design seedling pick-up mechanism based on given key points and trajectories,because it involves dimensional synthesis and rod length *** this paper,the dimensional synthesis of seedling pickup mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up *** the positions and orientations requirements of the five key points,the study first conducted a dimensional synthesis of the linkage size and center of *** next steps were to select a reasonable solution and optimize the data values based on the ideal seedling *** link motion was driven by the planetary gear train of the two-stage *** pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the *** the pitch curve with two convex points,the tooth profile design method of incomplete noncircular gear was *** seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter *** results were consistent with the theoretical design requirements,confirming that the mechanism meets the expected requirements for picking seedlings *** paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

关键词： Combined incomplete noncircular gear Mechanism dimension synthesis Planetary gear train Seedling pick-up mechanism

Double Position Servo Synchronous Drive System Based on Cross-Coupling Integrated Feedforward Control for Broacher

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 272-285页

作者： Wenqi LU Kehui JI Hanqing DONG Jianya ZHANG Quanwu WANG Liang GUO Faculty of Mechanical Engineering and Automation Zhejiang Sci-Tech University College of Electrical Engineering Zhejiang University

Synchronization errors directly deteriorate the machining accuracy of metal parts and the existed method cannot keep high synchronization precision because of external disturbances. A new double position servo synchronous driving scheme based on semi-closed-loop cross- coupling integrated feedforward control is proposed. The scheme comprises a position error cross-coupling feedfor-ward control and a load torque identification with feed- forward control. A digital integrated simulation system for the dual servo synchronous drive system is established. Using a 20 t servo broacher, performance analysis of the scheme is conducted based on this simulation system and the simulation results show that systems with traditional parallel or single control have problems when the work- table works with an unbalanced load. However, the system with proposed scheme shows good synchronous perfor- mance and positional accuracy. Broaching tests are performed and the experimental results show that the maximum dual axis synchronization error of the system is only 8μm during acceleration and deceleration processes and the error between the actual running position and the given position is almost zero. A double position servo synchronous driving scheme is presented based on crosscoupled integrated feedforward compensation control, which can improve the synchronization precision.

关键词： Broacher Double drive system Cross coupling position servo synchronous Integrated feedforward

Residence time distribution of high viscosity fluids falling film flow down outside of industrial-scale vertical wavy wall: Experimental investigation and CFD prediction

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1586-1594页

作者： Shichang Chen Lihao Zhang Yongjun Wang Xianming Zhang Wenxing Chen National Engineering Laboratory for Textile Fiber Materials and Processing technology (zhejiang) Zhejiang Sci-Tech University

The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and *** film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film *** comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good *** simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental *** work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.

关键词： Falling film flow High viscosity polymer fluid Residence time distribution Film thickness Numerical simulation