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Switching Frequency Improvement of a High Speed on/off Valve Based on Pre-excitation Control Algorithm

Chinese Journal of Mechanical Engineering 2024年第4期37卷 94-106页

作者： Qi Zhong Xiaotian Li Yongxin Mao Enguang Xu Tiwei Jia Yanbiao Li Huayong Yang College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China State key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China key laboratory of Special Purpose Equipment and Advanced Processing technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China

The high-speed on/off valve(HSV)serves as the fundamental component responsible for generating discrete fluids within digital hydraulic *** the switching frequency of the HSV increases,the properties of the generated discrete fluid approach those of continuous ***,a higher frequency response characteristic of HSV is the key to ensure the control accuracy of digital hydraulic ***,the current research mainly focuses on its dynamic performance,but neglect its *** paper presents a theoretical analysis demonstrating that the FRC of the HSV can be enhanced by minimizing its switching *** maximum switching frequency(MSF)is mainly determined by opening dynamic performance when HSV operates with low switching duty ratio(SDR),whereas the closing dynamic performance limits the MSF when HSV operates with high *** upon these findings,the pre-excitation control algorithm(PECA)is proposed to reduce the switching time of the HSV,and consequently enhance its *** results demonstrate that PECA shortens the opening delay time of HSV by 1.12 ms,the closing delay time by 2.54 ms,and the closing moving time by 0.47 ms in comparison to the existing advanced control *** a result,a larger MSF of 417 Hz and a wider controllable SDR range from 20%to 70%were achieved at a switching frequency of 250 ***,the proposed PFCA in this paper has been verified as an effective and promising approach for enhancing the control performance of digital hydraulic systems.

关键词： High speed on/off valve Switching frequency Pre-excitation Dynamic performance Switching duty ratio

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Low-temperature graphitization of lignin via Co-assisted electrolysis in molten salt

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Green Energy & Environment 2024年第9期9卷 1449-1458页

作者： Shijie Li Wei-Li Song Xue Han Qingqing Cui Yan-li Zhu Shuqiang Jiao Institute of Advanced Structure technology Beijing Institute of Technology State key laboratory of Advanced Metallurgy University of Science and Technology Beijing State key laboratory of Explosion science and technology Beijing Institute of Technology

The ever-growing energy demand and environmental issues have stimulated the development of sustainable energy ***,an efficient and environmentally friendly electrochemical transformation technology was proposed to prepare highly graphitized carbon materials from an abundant natural resource-lignin （LG）.The preparation process mainly includes pyrolytic carbonization of raw LG material and electrochemical conversion of amorphous carbon ***,with the assistance of Co catalyst,the graphitization degree of the products was significantly improved,in which the mechanism was the removal of heteroatoms in LG and the rearrangement of carbon atoms into graphite ***,tunable microstructures （nanoflakes） under catalytic effects could also be observed by controlling the electrolytic *** with the products CN1 （without catalyst） and CN5 （with 10%catalyst）,the specific surface area are 158.957 and202.246 m2g-1,*** used as the electrode material for lithium-ion batteries,CN5 delivered a competitive specific capacity of～350 m Ah g-1（0.5 C） compared with commercial *** strategy proposed in this work provides an effective way to extract value-added graphite materials from lignin and can be extended to the graphitization conversion of any other amorphous carbon precursor materials.

关键词： Lignin Graphitic carbon Electrochemical conversion Lithium-ion batteries

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Multi-Objective Optimization of VBHF in Deep Drawing Based on the Improved QO-Jaya Algorithm

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 189-202页

作者： Xiangyu Jiang Zhaoxi Hong Yixiong Feng Jianrong Tan State key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China key laboratory of Advanced Manufacturing technology of zhejiang Province Zhejiang UniversityHangzhou 310027China Ningbo Innovation Center Zhejiang UniversityNingbo 315100China

Blank holder force(BHF)is a crucial parameter in deep drawing,having close relation with the forming quality of sheet ***,there are different BHFs maintaining the best forming effect in different stages of deep *** variable blank holder force(VBHF)varying with the drawing stage can overcome this problem at an *** optimization of VBHF is to determine the optimal BHF in every deep drawing *** this paper,a new heuristic optimization algorithm named Jaya is introduced to solve the optimization *** improved“Quasi-oppositional”strategy is added to Jaya algorithm for improving population ***,an innovated stop criterion is added for better ***,the quality evaluation criteria for wrinkling and tearing are ***,the Kriging models are developed to approximate and quantify the relation between VBHF and forming defects under random ***,the optimization models are established and solved by the improved QO-Jaya algorithm.A VBHF optimization example of component with complicated shape and thin wall is studied to prove the effectiveness of the improved Jaya *** optimization results are compared with that obtained by other algorithms based on the TOPSIS method.

关键词： Variable blank holder force Multi-objective optimization QO-Jaya algorithm Algorithm stop criterion

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Determination of molecular energies via variational-based quantum imaginary time evolution in a superconducting qubit system

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science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 1-11页

作者： Zhiwen Zong Sainan Huai Tianqi Cai Wenyan Jin Ze Zhan Zhenxing Zhang Kunliang Bu Liyang Sui Ying Fei Yicong Zheng Shengyu Zhang Jianlan Wu Yi Yin zhejiang Province key laboratory of Quantum technology and Device School of PhysicsZhejiang UniversityHangzhou 310027China Tencent Quantum laboratory Shenzhen 518057China

As a valid tool for solving ground state problems,imaginary time evolution(ITE)is widely used in physical and chemical *** ITE-based algorithms in their quantum counterpart have recently been proposed and applied to some real *** experimentally realize the variational-based quantum imaginary time evolution(QITE)algorithm to simulate the ground state energy of hydrogen(H_2)and lithium hydride(Li H)molecules in a superconducting qubit *** H_2 molecule is directly simulated using the 3-qubit circuit with unitary-coupled clusters(UCC)*** also combine QITE with the cluster mean-field(CMF)method to obtain an effective *** Li H molecule is correspondingly simulated using the 3-qubit circuit with hardware-efficient *** comparison,the Li H molecule is also directly simulated using the 4-qubit circuit with UCC ansatz at the equilibrium *** the experimental results show a convergence within 4 iterations,with high-fidelity ground state energy *** a more complex system in the future,the CMF may allow further grouping of interactions to obtain an effective Hamiltonian,then the hybrid QITE algorithm can possibly simulate a relatively large-scale system with fewer qubits.

关键词： quantum computation quantum algorithm superconducting qubit

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State-sensitive convolutional sparse coding for potential biomarker identification in brain signals

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science China(Information sciences) 2024年第5期67卷 270-286页

作者： Puli WANG Yu QI Gang PAN College of Computer science and technology Zhejiang University State key laboratory of Brain-Machine Intelligence Zhejiang University MOE Frontier science Center for Brain science and Brain-machine Integration Zhejiang University Affiliated Mental Health Center & Hangzhou Seventh People's Hospital Zhejiang University School of Medicine

The identification of prototypical waveforms, such as sleep spindles and epileptic spikes, is crucial for the diagnosis of neurological disorders. These prototypical waveforms are usually recurrently presented in certain brain states, serving as potential biomarkers for clinical evaluations. Convolutional sparse coding(CSC) approaches have demonstrated strength in identifying recurrent patterns in time-series. However,existing CSC approaches do not explicitly explore state-specific patterns, making it difficult to identify state-related biomarkers. To address this problem, we propose state-sensitive CSC to learn state-specific prototypical waveforms. Specifically, we model signals of a certain state with specific waveforms that only appear frequently in this state and background waveforms that are independent of states. Based on this,state-sensitive CSC separates state-specific waveforms from background ones explicitly by incorporating incoherence constraints into optimizations. Experiments with epilepsy brain signals demonstrate that our approach can effectively identify prototypical waveforms in pre-ictal states, providing potential biomarkers for seizure prediction. Our approach provides a promising tool for automatic biomarker candidate identification.

关键词： convolutional sparse coding prototypical waveforms state-specific dictionary biomarker identification neural signal processing

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Highly sensitive nanozyme strip:An effective tool for forensic material evidence identification

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Nano Research 2024年第3期17卷 1785-1791页

作者： Juanji Hong Zhanjun Guo Dihan Duan Yi Zhang Xin Chen Yongjiu Li Zheng Tu Lei Feng Lei Chen Xiyun Yan Lizeng Gao Minmin Liang Demin Duan Experimental Center of Advanced Materials School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China College of Bioscience and Biotechnology Shenyang Agricultural UniversityShenyang 110866China Chongqing kangjuquanhong biology science and technology Co. ltdChongqing 400026China key laboratory of forensic Genetics Institute of Forensic ScienceMinistry of Public SecurityBeijing 100038China CAS Engineering laboratory for Nanozyme Key Laboratory of BiomacromoleculesInstitute of BiophysicsChinese Academic of ScienceBeijing 100101China

During criminal case investigations,blood evidence tracing is critical for criminal ***,the blood stains are often cleaned or covered up after the crime,resulting in trace residue and difficult ***,a highly sensitive and specific method for the rapid detection of human blood stains remains *** solve this problem,we established a nanozyme-based strip for rapid detection of blood evidence with high sensitivity and *** construct reliable nanozyme strips,we synthesized CoFe_(2)O_(4) nanozymes with high peroxidase-like activity by scaling up to gram level,which can be supplied for six million tests,and conjugated antibody as a detection probe in nanozyme *** developed CoFe_(2)O_(4) nanozyme strip can detect human hemoglobin(HGB)at a concentration as low as 1 ng/mL,which is 100 times lower than the commercially available colloidal gold strips(100 ng/mL).Moreover,this CoFe_(2)O_(4) nanozyme strip showed high generality on 12 substrates and high specificity to human HGB among 13 animal blood ***,we applied the developed CoFe_(2)O_(4) nanozyme strip to successfully detect blood stains in three real cases,where the current commercial colloidal gold strip failed to *** results suggest that the CoFe_(2)O_(4) nanozyme strip can be used as an effective on-scene detection method for human blood stains,and can further be used as a long-term preserved material evidence for traceability inquiry.

关键词： CoFe_(2)O_(4)nanozyme nanozyme strip peroxidase-like activity human hemoglobin blood evidence

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ER‐Mapping: An extrinsic robust coloured mapping system using residual evaluation and selection

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IET Cyber-Systems and Robotics 2024年第2期6卷 97-108页

作者： Changjian Jiang Zeyu Wan Ruilan Gao Yu Zhang State key laboratory of Industrial Control technology College of Control Science and EngineeringZhejiang UniversityHangzhouChina key laboratory of Collaborative Sensing and Autonomous Unmanned Systems of zhejiang Province HangzhouChina

The colour-enhanced point cloud map is increasingly being employed in fields such as robotics,3D reconstruction and virtual *** authors propose ER-Mapping(Extrinsic Robust coloured Mapping system using residual evaluation and selection).ER-Mapping consists of two components:the simultaneous localisation and mapping(SLAM)subsystem and the colouring *** SLAM subsystem reconstructs the geometric structure,where it employs a dynamic threshold-based residual selection in LiDAR-inertial odometry to improve mapping *** the other hand,the col-ouring subsystem focuses on recovering texture information from input images and innovatively utilises 3D–2D feature selection and optimisation methods,eliminating the need for strict hardware time synchronisation and highly accurate extrinsic *** were conducted in both indoor and outdoor *** results demonstrate that our system can enhance accuracy,reduce computational costs and achieve extrinsic robustness.

关键词： robot vision sensor fusion simultaneous localisation and mapping(robots)

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Inhibitory effect and mechanism of tannic acid against two starch digestive enzymes

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Food Quality and Safety 2024年第1期8卷 115-123页

作者：钟毓秀倪德让杨玉波李元一王莉田金虎杨帆叶兴乾 Department of Food science and Nutrition Zhejiang Key Laboratory for Agri-Food ProcessingFuli Institute of Food ScienceZhejiang R&D Centre for Food Technology and EquipmentZhejiang UniversityHangzhouChina Institute of science and technology Moutai GroupZunyiChina key laboratory of Industrial Microbial Resources Development Kweichow Moutai Co.Ltd.RenhuaiChina

Backgrounds:Tannic acid(TA),as a plant-derived phenolic substance,is involved in regulating the activity of starch digestive enzymes,but its underlying mechanism remains *** and Results:In the present study,inhibition rate and inhibition kinetics assays were performed and confrmed that TA had a strong inhibitory effect on bothα-amylase andα-glucosidase with IC50 values of 0.1585 mg/mL and 0.00542 mg/mL,respectively,through a mixed inhibition *** secondary structures of both enzymes were confrmed to be modifed by TA through circular dichroism(CD)*** quenching analysis revealed that the interaction between TA and two enzymes was a static process of pontaneous complex ***,molecular docking revealed that non-covalent bonds were the main interaction forces between TA and both ***:Thus,TA was a promising candidate for the inhibition of starch-digesting enzymes,and the present research provided insight into postprandial glucose regulation through polyphenols.

关键词： Tannic acid α-amylase α-glucosidase inhibition starch digestion.

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Ultra-homogeneous dense Ag nano layer enables long lifespan solid-state lithium metal batteries

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Journal of Energy Chemistry 2024年第9期96卷 110-119页

作者： Yaning Liu Tianqi Yang Ruyi Fang Chengwei Lu Ruojian Ma Ke Yue Zhen Xiao Xiaozheng Zhou Wenkui Zhang Xinping He Yongping Gan Jun Zhang Xinhui Xia Hui Huang Xinyong Tao Yang Xia College of Materials science and Engineering Zhejiang University of TechnologyHangzhou 310014ZhejiangChina key laboratory of Rare Earth Optoelectronic Materials and Devices of zhejiang Province Institute of Optoelectronic Materials and DevicesChina Jiliang UniversityHangzhou 310018ZhejiangChina

The unstable electrolyte/lithium(Li)anode interface has been one of the key challenges in realizing high energy density solid-state lithium metal batteries(LMBs)***,a dense and uniform silver(Ag)nano interlayer with a thickness of∼35 nm is designed accurately by magnetron sputtering technology to optimize the electrolyte/Li anode *** Ag nano layer reacts with Li metal anode to in-situ form Li-Ag alloy,thus enhancing the physical interfacial contact,and further improving the interfacial wettability and *** particular,the Li-Ag alloy is inclined to form AgLi phase proved by cryo-TEM and DFT,effectively preventing SN from continuously“attacking”the Li metal anode due to the lower adsorption of succinonitrile(SN)molecules on AgLi than that of pure Li metal,thereby significantly reinforcing the interfacial ***,the enhanced physical and chemical stability of electrolyte/Li anode interface promotes the homogeneous deposition of Li^(+)and inhibits the dendrite *** Li-symmetric cell maintains stable operation for up to 1700 h and the cycling stability of LiFePO_(4)|SPE|Li full cell is remarkably improved at room temperature(capacity retention rate of 91.9%for 200 cycles).This work opens an effective way for accurate and controllable interface design of long lifespan solid-state LMBs.

关键词： Silvernano layer Poly(ethylene oxide) Solid polymer electrolyte Succinonitrile Lithium metal battery

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Accurate Source-Receiver Positioning Method for a High-Resolution Deep-Towed Multichannel Seismic Exploration System

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Journal of Ocean University of China 2024年第2期23卷 415-426页

作者： LI Jing LIU Kai WEI Zhengrong ZHANG Liancheng LIU Yangting PEI Yanliang LIU Chenguang LIU Baohua key laboratory of Marine Geology and Metallogeny First Institute of OceanographyMNRQingdao 266061China laboratory for Marine Geology Laoshan LaboratoryQingdao 266061China College of Ocean science and Engineering Shandong University of Science and TechnologyQingdao 266590China key laboratory of Fluid Transmission technology of zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China

The near-seabed multichannel seismic exploration systems have yielded remarkable successes in marine geological disaster assessment,marine gas hydrate investigation,and deep-sea mineral exploration owing to their high vertical and horizontal ***,the quality of deep-towed seismic imaging hinges on accurate source-receiver positioning *** light of existing technical problems,we propose a novel array geometry inversion method tailored for high-resolution deep-towed multichannel seismic exploration *** method is independent of the attitude and depth sensors along a deep-towed seismic streamer,accounting for variations in seawater velocity and seabed slope *** approach decomposes the towed line array into multiline segments and characterizes its geometric shape using the line segment distance and pitch *** optimization parameters for seawater velocity and seabed slope angle,we establish an objective function based on the model,yielding results that align with objective *** the particle swarm optimization algorithm enables synchronous acquisition of optimized inversion results for array geometry and seawater *** validation using theoretical models and practical data verifies that our approach effectively enhances source and receiver positioning inversion *** algorithm exhibits robust stability and reliability,addressing uncertainties in seismic traveltime picking and complex seabed topography conditions.

关键词： high-resolution deep-towed multichannel seismic exploration source-receiver positioning array geometry inversion seawater heterogeneity seabed slope angle

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