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Real-Time Iterative Compensation Framework for Precision Mechatronic Motion Control Systems

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1218-1232页

作者： Chuxiong Hu Ran Zhou Ze wang yu Zhu Masayoshi Tomizuka State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084 Beijing Key Laboratory of Precision/Ultra-Precision Manufacture Equipments and Control Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering University of CaliforniaBerkeleyCA 94720-1740 USA IEEE

With regard to precision/ultra-precision motion systems,it is important to achieve excellent tracking performance for various trajectory tracking tasks even under uncertain external *** this paper,to overcome the limitation of robustness to trajectory variations and external disturbances in offline feedforward compensation strategies such as iterative learning control(ILC),a novel real-time iterative compensation(RIC)control framework is proposed for precision motion systems without changing the inner closed-loop ***,the RIC method can be divided into two parts,i.e.,accurate model prediction and real-time iterative *** accurate prediction model considering lumped disturbances is firstly established to predict tracking errors at future sampling *** light of predicted errors,a feedforward compensation term is developed to modify the following reference trajectory by real-time iterative *** the prediction and compen-sation processes are finished in a real-time motion control sampling *** stability and convergence of the entire control system after real-time iterative compensation is analyzed for different *** simulation results consistently demonstrate that the proposed RIC framework possesses satisfactory dynamic regulation capability,which contributes to high tracking accuracy comparable to ILC or even better and strong robustness.

关键词： Precision motion control prediction model real-time iterative compensation trajectory tracking

Future variation of land surface temperature in the Yangtze River Basinbasedon CMIP6 model

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International Journal of Digital Earth 2023年第1期16卷 2776-2796页

作者： Jinlian Liu Hanya Tang Fengqin Yan Shiwei Liu Xuguang Tang zhi Ding Pujia yu Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Chongqing Key Laboratory of Karst Environment School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China

In recent years,past changes in global and regional land surface temperatures(LST)have been well studied,however,future LST changes have been largely ignored owing to data *** this study,three climate variables of CMIP6,namely air temperature(AT),precipitation(Pre),and leaf area index(LAl),were spatially corrected using the Delta downscaling *** this basis,by combining MODIS LST,elevation,slope and aspect,a random forest(RF)model was built to calculate the LST from 2022 to *** absolute variability(AV)and Mann-Kendall(M-K)tests were used to quantitatively detect interannual and seasonal LST changes in different Shared Socioeconomic Pathways(SSPs)*** results showed that the AV value increased successively from SSP1-2.6 to SSP2-4.5 and then to *** with the base period(2003-2021),the increment in interannual,spring,summer and autumn LST during 2022-2100 was mainly between 1 and 2°℃under *** interannual and seasonal LST were spatially characterized by significant warming over large areas,and the increasing was the fastest under *** results indicate that,in the future,LST will increase further over large areas,especially in winter.

关键词： Temporal and spatial changes Delta downscaling Random forest Global warming

The role of CO_(2)dissociation in CO_(2)hydrogenation to ethanol on CoCu/silica catalysts

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Nano Research 2023年第5期16卷 6128-6133页

作者： Zhongyan wang Chengsheng Yang Xianghong Li Xiwen Song Chunlei Pei zhi-Jian Zhao Jinlong Gong Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin 300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

CoCu-based catalysts are widely used in CO_(x) hydrogenation reactions to produce higher alcohols due to the C–C coupling ability of Co and the ability of Cu to produce *** work describes the role of easily happened CO_(2)dissociation on the CoCu surface during the reaction,using different silica support to tune the metal–support interaction,reaches different selectivity to *** supported on mesoporous silica MCM-41 shows ethanol selectivity as high as 85.3%,the ethanol space-time yield(STY)is 0.229 mmol/(gmetal∙h),however,poor selectivity to ethanol as low as 28.8%is observed on CoCu supported on amorphous *** different selectivity is due to the different intensities of CO_(2)dissociation on the *** adsorbed O*produced via CO_(2)dissociation can occupy the cobalt hollow sites on CoCu surfaces,which are also the adsorption sites of C1 intermediates for further C–C coupling.

关键词： CO_(2)hydrogenation bimetallic catalysts cobalt catalysts CO_(2)dissociation ethanol synthesis

A novel NIRS modelling method with OPLS-SPA and MIX-PLS for timber evaluation

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Journal of Forestry Research 2022年第1期33卷 369-376页

作者： Jinhao Chen Huilig yu Dapeng Jiang Yizhuo Zhang Keqi wang College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China College of Information and Computer Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China

The identification of timber properties is important for safe *** Infrared Spectroscopy(NIRS)technology is widely-used because of its simplicity,efficiency,and positive environmental ***,in its application,weak signals are extracted from complex,overlapping and changing *** study focused on the stability of NIR *** Orthogonal Partial Least Squares(OPLS)and Successive Projections Algorithm(SPA)eliminates noise and extracts effective spectra,and an ensemble learning method MIX-PLS,is applied to establish the *** elastic modulus of timber is taken as an example,and 201 wood samples of three species,Xylosmacongesta(Lour.)Merr.,Acer pictum ***,and Betula pendula,samples were divided into three groups to investigate modelling *** results show that OPLS can preprocess the near-infrared spectroscopy information according to the target object in the face of the system error and reduce errors to *** finally selects 13 spectral bands,simplifies the NIR spectral data and improves model *** Pearson's correlation coefficient of Calibration(Rc)and the Pearson's correlation coefficient of Prediction(Rp)of Mix Partial Least Squares(MIX-PLS)were 0.95 and 0.90,and Root Mean Square Error of Calibration(RMSEC)and Root Mean Square Error of Prediction(RMSEP)are 2.075 and 6.001,respectively,which shows the model has good generalization abilities.

关键词： NIR prediction Orthogonal partial least squares(OPLS) Successive projections algorithm(SPA) Mix partial least squares(MIX-PLS)modulus of elasticity

Constructing dual-functional porphyrin-based thorium metal-organic framework toward photocatalytic uranium(Ⅵ)reduction integrated with organic oxidation

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Science China Chemistry 2022年第8期65卷 1544-1551页

作者： zhi Gao yue wang yuzhi Lin zhijian Zheng Yao Liu Qiqi Jing Feng Luo Jiangxi Province Key Laboratory of Synthetic Chemistry East China University of TechnologyNanchang 330013China

The rational fabrication of photocatalysts with dual functions upon visible light, such as photocatalytic radioactive U(Ⅵ)reduction and value-added organic oxidation, is highly desirable but remains huge challenge. Here, we couple the photocatalytic U(Ⅵ) reduction with the oxidative organic synthesis to one system using novel extended π-conjugated framework(Cu@ThTCPP) without the expense of sacrificial reagents. Noticeably, the as-prepared Cu@Th-TCPP linked by tetratopic tetrakis(4-carboxyphenyl)porphyrin(TCPP) ligand and unique Th(μ-O)(HCOO)(HO)secondary building unit(SBU) exhibits significantly enhanced activity when the photocatalytic U(Ⅵ) reduction and thioanisole oxidation were integrated to one *** experimental characterizations demonstrate that the highly conjugated framework of Cu@Th-TCPP is good for the charge transfer and separation, while incorporating Cusite further accelerates the charge-carrier dynamics, thus giving rise to the dual-functional property. Apparently, this strategy conforms to atomic economy, opens a new horizon to address radioactive environmental pollution in natural water systems and soils, and simultaneously produces valuable chemicals.

关键词： radioactive U(Ⅵ)reduction oxidative organic synthesis charge separation dual-functional Th-MOF photocatalysis

Improving accuracy of automatic optical inspection with machine learning

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Frontiers of Computer Science 2022年第1期16卷 45-56页

作者： Xinyu TONG Ziao yu Xiaohua TIAN Houdong GE Xinbing wang Department of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai200240China Ambit Microsystems Shanghai201600China

Electronic devices require the printed circuit board(PCB)to support the whole structure,but the assembly of PCBs suffers from welding problem of the electronic components such as surface mounted devices(SMDs)*** automated optical inspection(AOI)machine,widely used in industrial production,can take the image of PCBs and examine the welding ***,the AOI machine could commit false negative errors and dedicated technicians have to be employed to pick out those misjudged *** paper proposes a machine learning based method to improve the accuracy of *** particular,we propose an adjacent pixel RGB value based method to pre-process the image from the AOI machine and build a customized deep learning model to classify the *** present a practical scheme including two machine learning procedures to mitigate AOI *** conduct experiments with the real dataset from a production line for three months,the experimental results show that our method can reduce the rate of misjudgment from 0.3%–0.5%to 0.02%–0.03%,which is meaningful for thousands of PCBs each containing thousands of electronic components in practice.

关键词： automated optical inspection industrial internet of things machine learning image classification

Investigation on the Performance of the Pump-Free Double Heat Source Ejector Refrigeration System with R1234yf

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Journal of Thermal Science 2022年第5期31卷 1452-1464页

作者： yu Meihong ZHAO Hongxia wang Xinli HAN Jitian LAI Yanhua School of Energy and Power Engineering Shandong UniversityJi’nan250061China School of Control Science and Engineering Shandong UniversityJi’nan250061China

A pump is needed in an ejector refrigeration system,which makes the system high cost and complicated and hinders its application.A pump-free double heat source ejector refrigeration system using R1234yf as working fluid is proposed in which an injector driven by another heat source replaces the liquid circulating pump,making the system more affordable,simpler and more *** effect of different operation conditions on entrainment ratios and the influence of different factors on system performance are analyzed on the basis of mass,momentum and energy conservation *** influence degree of each factor on system performance is investigated by the orthogonal test *** condenser temperature has the largest effect on system *** pressure drop in the suction chamber of gas-liquid injector has the least impact on system *** COP can reach about 0.35 under a certain working *** system can be driven by two different temperature heat sources with no electricity needed,and it is a good choice for places with abundant heat resources or lack of electricity.

关键词： ejector refrigeration system injector entrainment ratio coefficient of performance(COP)

Data Security Storage Mechanism Based on Blockchain Network

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Computers, Materials & Continua 2023年第3期74卷 4933-4950页

作者： Jin wang WeiOu Wenhai wang RSimon Sherratt Yongjun Ren Xiaofeng yu School of Computer&Communication Engineering Changsha University of Science&TechnologyChangsha410004China School of Control Science and Engineering Zhejiang UniversityHangzhou310058China School of Systems Engineering The University of ReadingReadingRG66AYUK School of Computer Engineering Research Center of Digital Forensics of Ministry of EducationNanjing University of Information Science&TechnologyNanjing210044China School of Business Nanjing UniversityNanjing210093China

With the rapid development of information technology,the development of blockchain technology has also been deeply *** performing block verification in the blockchain network,if all transactions are verified on the chain,this will cause the accumulation of data on the chain,resulting in data storage *** the same time,the security of data is also challenged,which will put enormous pressure on the block,resulting in extremely low communication efficiency of the *** traditional blockchain system uses theMerkle Tree method to store *** verifying the integrity and correctness of the data,the amount of proof is large,and it is impossible to verify the data in batches.A large amount of data proof will greatly impact the verification efficiency,which will cause end-to-end communication delays and seriously affect the blockchain system’s stability,efficiency,and *** order to solve this problem,this paper proposes to replace the Merkle tree with polynomial commitments,which take advantage of the properties of polynomials to reduce the proof size and communication *** realizing the ingenious use of aggregated proof and smart contracts,the verification efficiency of blocks is improved,and the pressure of node communication is reduced.

关键词： Blockchain cryptographic commitment smart contract data storage

Non-viral and viral delivery systems for CRISPR-Cas9 technology in the biomedical field

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Science China(Life Sciences) 2017年第5期60卷 458-467页

作者： zhi-Yao He Ke Men Zhou Qin Yang Yang Ting Xu yu-Quan Wei Department of Pharmacy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu 610041 China State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University and Collaborative Innovation Center of Biotherapy Chengdu 610041 China

The clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9(CRISPR-Cas9) system provides a novel genome editing technology that can precisely target a genomic site to disrupt or repair a specific gene. Some CRISPR-Cas9 systems from different bacteria or artificial variants have been discovered or constructed by biologists, and Cas9 nucleases and single guide RNAs(sgRNA) are the major components of the CRISPR-Cas9 system. These Cas9 systems have been extensively applied for identifying therapeutic targets, identifying gene functions, generating animal models, and developing gene ***, CRISPR-Cas9 systems have been used to partially or completely alleviate disease symptoms by mutating or correcting related genes. However, the efficient transfer of CRISPR-Cas9 system into cells and target organs remains a challenge that affects the robust and precise genome editing activity. The current review focuses on delivery systems for Cas9 mRNA, Cas9 protein, or vectors encoding the Cas9 gene and corresponding sgRNA. Non-viral delivery of Cas9 appears to help Cas9 maintain its on-target effect and reduce off-target effects, and viral vectors for sgRNA and donor template can improve the efficacy of genome editing and homology-directed repair. Safe, efficient, and producible delivery systems will promote the application of CRISPR-Cas9 technology in human gene therapy.

关键词： genome editing CRISPR Cas9 viral vector non-viral vector gene therapy