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Reduction of unactivated alkyl chlorides enabled by light-induced single electron transfer

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Science China Chemistry 2024年第2期67卷 471-481页

作者： Lei Dai zhao-Fei zhang Xiang-Yu Chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing100049China Institute of Chemistry Chinese Academy of SciencesBeijing100190China Binzhou Institute of Technology Weiqiao-UCAS Science and Technology ParkBinzhou256606China

Alkyl chlorides are abundant and easily accessible starting ***,due to the high reduction potentials associated with unactivated alkyl chlorides,achieving their single electron reduction remains a persistent *** challenge has spurred the exploration of efficient activation methods to overcome this *** recent years,photocatalysis has emerged as a mild and potent tool for the single electron reduction of unactivated alkyl chlorides,opening up new possibilities in this *** the rapid advancements in this area,a comprehensive review that provides a conceptual understanding of this emerging field,with a specific focus on reaction design and catalytic mechanisms,would be timely and highly ***,we present an overview of various synthetic techniques for photoinduced single electron reduction of unactivated alkyl ***,we also discuss the limitations of the present methods and future directions that lie ahead in this field.

关键词： photocatalysis unactivated alkyl chlorides single electron transfer radical reactions

Geometric error measuring,modeling,and compensation for CNC machine tools:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： zhao zhang Feng JIANG Ming LUO Baohai WU Dinghua zhang Kai TANG Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

Recent Research Progress of Paper-Based Supercapacitors Based on Cellulose

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Energy & Environmental Materials 2024年第3期7卷 345-373页

作者： Chuanyin Xiong Tianxu Wang Jing Han zhao zhang Yonghao Ni College of Bioresources Chemical&Materials Engineering Shaanxi University of Science and TechnologyXi'an 710021China School of Materials Science and Engineering Tianjin Polytechnic UniversityTianjin 300387China Department of Chemical and Biomedical Engineering The University of MaineOronoMaine 04469USA University of New Brunswick Limerick Pulp&Paper CtrFredericton New Brunswick E3B 5A3Canada

In recent years,paper-based functional materials have received extensive attention in the field of energy storage due to their advantages of rich and adjustable porous network structure and good *** an important energy storage device,paper-based supercapacitors have important application prospects in many fields and have also received extensive attention from researchers in recent *** present,researchers have modified and regulated paper-based materials by different means such as structural design and material composition to enhance their electrochemical storage *** development of paper-based supercapacitors provides an important direction for the development of green and sustainable ***,it is of great significance to summarize the relevant work of paper-based supercapacitors for their rapid development and *** this review,the recent research progress of paper-based supercapacitors based on cellulose was summarized in terms of various cellulose-based composites,preparation skills,and electrochemical ***,some opinions on the problems in the development of this field and the future development trend were *** is hoped that this review can provide valuable references and ideas for the rapid development of paper-based energy storage devices.

关键词： cellulose electrochemical performance flexibility paper-based supercapacitor porous

Color Image Compression and Encryption Algorithm Based on 2D Compressed Sensing and Hyperchaotic System

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Computers, Materials & Continua 2024年第2期78卷 1977-1993页

作者： Zhiqing Dong zhao zhang Hongyan Zhou Xuebo Chen School of Computer Science and Software Engineering University of Science and Technology LiaoningAnshan114051China School of Electronic and Information Engineering University of Science and Technology LiaoningAnshan114051China

With the advent of the information security era,it is necessary to guarantee the privacy,accuracy,and dependable transfer of *** study presents a new approach to the encryption and compression of color *** is predicated on 2D compressed sensing(CS)and the hyperchaotic ***,an optimized Arnold scrambling algorithm is applied to the initial color images to ensure strong ***,the processed images are con-currently encrypted and compressed using 2D *** them,chaotic sequences replace traditional random measurement matrices to increase the system’s ***,the processed images are re-encrypted using a combination of permutation and diffusion *** addition,the 2D projected gradient with an embedding decryption(2DPG-ED)algorithm is used to reconstruct *** with the traditional reconstruction algorithm,the 2DPG-ED algorithm can improve security and reduce computational ***,it has better *** experimental outcome and the performance analysis indicate that this algorithm can withstand malicious attacks and prove the method is effective.

关键词： Image encryption image compression hyperchaotic system compressed sensing

Identification of reservoir types in deep carbonates based on mixedkernel machine learning using geophysical logging data

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Petroleum Science 2024年第3期21卷 1632-1648页

作者： Jin-Xiong Shi Xiang-Yuan zhao Lian-Bo Zeng Yun-zhao zhang Zheng-Ping Zhu Shao-Qun Dong Key Laboratory of Exploration Technologies for Oil and Gas Resources of the Ministry of Education Yangtze UniversityWuhan4310HubeiChina School of Geosciences Yangtze UniversityWuhan430100HubeiChina College of Geosciences China University of Petroleum(Beijing)Beijing102249China Petroleum Exploration and Production Research Institute of SINOPEC Beijing100083China School of Earth Sciences and Engineering Xi'an Shiyou UniversityXi'an 710065ShaanxiChina

Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage *** cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging ***,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ***,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data *** address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,*** MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input *** particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD *** evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM ***,the built MKFD model was applied in a blind well test,and a variable importance analysis was *** comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger *** MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.

关键词： Reservoir type identification Geophysical logging data Kernel Fisher discriminantanalysis Mixedkernel function Deep carbonates

Bolstering the Mechanical Robustness of Supramolecular Polymer Network by Mechanical Bond

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Chinese Journal of Polymer Science 2024年第10期42卷 1536-1544,I0012页

作者： Yuan-Hao Wang Jing-Xi Deng Jun zhao Yi Ding Li Yang zhao-Ming zhang Xu-Zhou Yan School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai200240China Frontiers Science Center for Transformative Molecules Shanghai Jiao Tong UniversityShanghai200240China

Supramolecular polymer networks(SPNs)are celebrated for their dynamic nature,yet they often exhibit inadequate mechanical *** far,the quest to bolster the mechanical resilience of SPNs while preserving their dynamic character presents a formidable ***,we introduce[2]rotaxane into SPN to serve as another cross-link,which could effectively enhance the mechanical robustness of the polymer network without losing the dynamic *** with SPN,the dually cross-linked network(DPN)demonstrates superior breaking strength,Young’s modulus,puncture force and toughness,underscoring its superior ***,the cyclic tensile tests reveal that the energy dissipation capacity of DPN rivals,and in some cases surpasses,that of SPN,owing to the efficient energy dissipation pathway facilitated by[2]*** addition,benefiting from stable topological structure of[2]rotaxane,DPN exhibits accelerated recovery from deformation,indicating superior elasticity compared to *** strategy elevates the performance of SPNs across multiple metrics,presenting a promising avenue for the development of high-performance dynamic materials.

关键词： Rotaxane cross-links Dually cross-linked network Supramolecular polymer network Host-guest recognition Dynamic materials

Diabetic retinopathy identification based on multi-sourcefree domain adaptation

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1193-1204页

作者： Guang-Hua zhang Guang-Ping Zhuo zhao-Xia zhang Bin Sun Wei-Hua Yang Shao-Chong zhang School of Big Data Intelligent Diagnosis&Treatment Industry Taiyuan UniversityTaiyuan 030032Shanxi ProvinceChina Shanxi Key Laboratory of Intelligent Optimization Computing and Blockchain Technology Taiyuan Normal UniversityTaiyuan 030619Shanxi ProvinceChina Shanxi Eye Hospital Taiyuan 030002Shanxi ProvinceChina College of Computer Science and Technology Taiyuan Normal UniversityTaiyuan 030619Shanxi ProvinceChina Shenzhen Eye Institute Shenzhen Eye HospitalJinan UniversityShenzhen 518040Guangdong ProvinceChina

AIM:To address the challenges of data labeling difficulties,data privacy,and necessary large amount of labeled data for deep learning methods in diabetic retinopathy(DR)identification,the aim of this study is to develop a source-free domain adaptation(SFDA)method for efficient and effective DR identification from unlabeled ***:A multi-SFDA method was proposed for DR *** method integrates multiple source models,which are trained from the same source domain,to generate synthetic pseudo labels for the unlabeled target ***,a softmax-consistence minimization term is utilized to minimize the intra-class distances between the source and target domains and maximize the inter-class *** is performed using three color fundus photograph datasets(APTOS2019,DDR,and EyePACS).RESULTS:The proposed model was evaluated and provided promising results with respectively 0.8917 and 0.9795 F1-scores on referable and normal/abnormal DR identification *** demonstrated effective DR identification through minimizing intra-class distances and maximizing inter-class distances between source and target ***:The multi-SFDA method provides an effective approach to overcome the challenges in DR *** method not only addresses difficulties in data labeling and privacy issues,but also reduces the need for large amounts of labeled data required by deep learning methods,making it a practical tool for early detection and preservation of vision in diabetic patients.

关键词： diabetic retinopathy multisource-free domain adaptation pseudo-label generation softmaxconsistence minimization

Performance improvements in complementary metal oxide semiconductor devices and circuits based on fin field-effect transistors using 3-nm ferroelectric Hf_(0.5)Zr_(0.5)O_(2)

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Rare Metals 2024年第7期43卷 3242-3249页

作者： zhao-Hao zhang Yan-Na Luo Gao-Bo Xu Jia-Xin Yao Zhen-Hua Wu Hong-Bin zhao Qing-Zhu zhang Hua-Xiang Yin Jun Luo Wen-Wu Wang Hai-Ling Tu Integrated Circuit Advanced R&D Center Institute of Microelectronics of Chinese Academy of SciencesBeijing 100029China School of Integrated Circuits University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Advanced Materials for Smart Sensing General Research Institute for Nonferrous MetalsBeijing 100088China

In this work,a conventional HfO_(2) gate dielectric layer is replaced with a 3-nm ferroelectric(Fe) HZO layer in the gate stacks of advanced fin field-effect transistors(FinFETs).Fe-induced characteristics,e.g.,negative drain induced barrier lowering(N-DIBL) and negative differential resistance(NDR),are clearly observed for both p-and n-type HZO-based *** characteristics are attributed to the enhanced ferroelectricity of the 3-nm hafnium zirconium oxide(HZO) film,caused by Al doping from the TiAlC capping *** mechanism is verified for capacitors with structures similar to the *** to the enhanced ferroelectricity and N-DIBL phenomenon,the drain current(I_(DS))of the HZO-FinFETs is greater than that of HfO_(2)-FinFETs and obtained at a lower operating ***,circuits based on HZO-FinFET achieve higher performance than those based on HfO_(2)-FinFET at a low voltage drain(V_(DD)),which indicates the application feasibility of the HZO-FinFETs in the ultralow power integrated circuits.

关键词： FinFET Ferroelectric Hafnium zirconium oxide Subthreshold swing Low power

Experimental Study of Electrical‑Assisted Nanomachining of Monocrystalline Copper Using Customized Tungsten Tip

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Nanomanufacturing and Metrology 2024年第2期7卷 60-75页

作者： Tao Wang Yanling Tian Zhilai Lu Weijie Wang zhao zhang Guangwei Zhu Hui Tang Dawei zhang Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China School of Engineering University of WarwickCoventry CV47ALUK State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China

As a promising micro/nanofabrication method,electrical-assisted nanomachining has obtained substantial attention due to its high material removal rate and attainable superior surface *** this study,a rectangular wave electrical signal was applied for nanomachining by a customized tungsten *** to the coupling effect between the electric field and mechanical force,the cutting depth of the machined grooves can be *** electrical-assisted groove processing,a depth of 270 nm and an aspect ratio of 0.6 on the copper sample can be *** influence of operation parameters including applied voltage,frequency,duty ratio,normal force and cutting speed on the machining performance was investigated in terms of the groove depth,width,aspect ratio,and surface *** potential machining mechanisms should be a combination of electric field force,nanoscale electric discharge,electric contact thermal effects,possible annealing behavior,and scraping and plowing actions induced by mechanical forces.

关键词： Tip-based nanofabrication Electrical-assisted machining Nanoscale scratching Machining parameters