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A Robotic System with Robust Remote Center of Motion Constraint for Endometrial Regeneration Surgery

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 169-181页

作者： Jianhua Li Chongyang Wang Zhenxing Wang Xiong zheng zhidong Wang Jichun Tan Hao Liu State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China Shenyang Jianzhu University Shenyang 110168China Chiba Institute of Technology Chiba 275-0016Japan Shengjing Hospital of China Medical University Shenyang 110016China

Surgical robots have been widely used in diferent procedures to improve and facilitate the ***,there is no robot designed for endometrial regeneration surgery,which is a new therapy for restoring fertility in women using stem *** regeneration surgery requires processing of the endometrium and transplantation of stem cells with minimal trauma to the *** this paper,we introduce a surgical robotic system that consists of a dexterous hysteroscope,supporting arm,and additional novel instruments to facilitate the operation and decrease trauma to the *** center of motion(RCM)constraint is required to protect the cervix of the ***,the supporting arm and hysteroscope are controlled separately in kinematics to ensure that the RCM constraint and hysteroscope’s shape and posture are ***,a task-decoupled method is used to improve the robustness of the RCM *** confrm that the proposed method is more robust and achieves higher RCM *** addition,the master-slave control of a robot with RCM constraint is also *** study proposes the realization of a robot with robust RCM control for endometrial regeneration surgery.

关键词： Endometrial regeneration Surgical robot Remote center of motion Task decoupled

Modulating charge separation and transfer kinetics in carbon nanodots for photoredox catalysis

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Journal of Energy Chemistry 2020年第11期29卷 365-377页

作者： Pengju Yang zhidong Yang School of Chemistry and Chemical Engineering Shanxi UniversityTaiyuan 030006ShanxiChina

Artificial photosynthesis has gained increasing interest as a promising solution to the worldwide energy and environmental issues. A crucial requirement for realizing a sustainable system for artificial photosynthesis is to explore low cost, highly-efficient and stable photoactive materials. Carbon nanodots(CNDs) have attracted considerable attention owing to their low cost, tunable chemistry and unique light-harvesting capability. Previous review articles have highlighted the photocatalytic and photoelectrocatalytic applications of CNDs and CNDs-based composite photocatalysts. However, the control of the separation and transfer processes of photogenerated electron/hole pairs in CNDs has not been *** review summarizes the recent progress in the design of CNDs as new light-harvesting materials and highlights their applications in photocatalytic hydrogen production, CO2 photoreduction and environmental remediation. Strategies that have been employed to modulate the separation and transfer kinetics of photogenerated charge carriers in CNDs are discussed in detail. The challenges and new directions in this emerging area of research are also proposed.

关键词： Carbon nanodot Artificial photosynthesis Charge separation Visible light

General Decay Synchronization for Recurrent Neural Networks with Mixed Time Delays

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Journal of Systems Science & Complexity 2020年第3期33卷 672-684页

作者： MUHAMMADHAJI Ahmadjan TENG zhidong College of Mathematics and Systems Science Xinjiang UniversityUrumqi 830046China

This paper studies the general decay synchronization(GDS)of a class of recurrent neural networks(RNNs)with general activation functions and mixed time *** constructing suitable Lyapunov-Krasovskii functionals and employing useful inequality techniques,some sufficient conditions on the GDS of considered RNNs are established via a type of nonlinear *** addition,one example with numerical simulations is presented to illustrate the obtained theoretical results.

关键词： General activation functions general decay synchronization mixed time delay recurrent neural network

An epidemiological analysis of the Beijing 2008 Hand-Foot-Mouth epidemic

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Chinese Science Bulletin 2010年第12期55卷 1142-1149页

作者： CAO zhidong ZENG DaJun WANG QuanYi zheng XiaoLong WANG FeiYue Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing 100190 China Beijing Center for Disease Control and Prevention Beijing 100013 China

This paper presents an empirical analysis of the epidemiological data concerning the 18445 HFMD-infected cases in Beijing in *** main findings are as follows.(i) Seasonal variations in incidence were observed,with a peak observed during the summer season,especially in *** patients outnumber female patients by 1.57:1.(ii) Most cases occurred in children 4 years old or *** Weibull distribution and Gamma distribution as to model fitness when analyzing patient ages,log-normal distribution indicates that the estimated mean age is 3.4 years.(iii) The age distribution seems to indicate cyclic peaks with roughly one-year intervals.(iv) Correlation analyses (ρ=0.9864) show that time of birth in different months has an impact on the chance of being infected by *** month seems to present a high risk factor on infants and young children.(v) The morbidity rate is 132.7/100000 during the HFMD epidemic in Beijing in *** morbidity map shows that the risks of HFMD infection in areas close to the city center and suburbans are much lower than those in the urban-rural transition *** risks inferred from the morbidity map demonstrate a clear circular pattern.(vi) The prevention and control measures taken by the public health departments seem to be effective during the summer season,resulting in the early ending of the epidemic (one month earlier than the natural season) and reduced outbreak size.

关键词：流行病学分析疫情北京 Weibull分布模型作者对数正态分布季节变化平均年龄

Reversible magnetocaloric effect and refrigeration capacity enhanced by two successive magnetic transitions in DyB2

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Science China(Technological Sciences) 2012年第2期55卷 501-504页

作者： MENG Hui LI Bing HAN zheng ZHANG YuQin WANG XianWei ZHANG zhidong Shenyang National Laboratory for Materials Science and International Center for Materials PhysicsInstitute of Metal ResearchChinese Academy of SciencesShenyang 110016China

A large and reversible magnetocaloric effect is found in the compound DyB2, which is associated with two successive mag- netic transitions： a spin-reorientation-like transition followed by a ferromagnetic-paramagnetic transition. These two transitions appreciably enlarge the magnetic-refrigeration temperature window and yield a huge refrigeration capacity of 610 J kg^-1, with a maximum magnetic entropy change -ASmax of 17 J kg^-1K^-1, at a magnetic-field change of 5 T. The corresponding values for low magnetic-field change of 2 T are 193 J kg^-1 and 7.4 J kg-lK^-1, respectively.

关键词： DyB2 magnetocaloric effect refrigeration capacity

A Two-Stage State Recognition Method for Asynchronous SSVEP-Based Brain-Computer Interface System

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机器人 2013年第1期35卷 45-51页

作者： ZHANG Zimu DENG zhidong State Key Laboratory of Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and TechnologyDepartment of Computer Science and TechnologyTsinghua University

A two-stage state recognition method is proposed for asynchronous SSVEP(steady-state visual evoked potential) based brain-computer interface(SBCI) *** two-stage method is composed of the idle state(IS) detection and control state(CS) discrimination *** on blind source separation and continuous wavelet transform techniques,the proposed method integrates functions of multi-electrode spatial filtering and feature *** IS detection module,a method using the ensemble IS feature is *** CS discrimination module,the ensemble CS feature is designed as feature vector for control intent ***,performance comparisons are investigated among our IS detection module and other existing *** the experimental results validate the satisfactory performance of our CS discrimination module.

关键词：检测模块机器人连续小波变换技术视觉诱发

BUCKLING ANALYSIS OF STRETCHABLE FERROELECTRIC THIN FILM ON ELASTOMERIC SUBSTRATES

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Acta Mechanica Solida Sinica 2014年第5期27卷 509-517页

作者： zhidong Zhou Quan Jiang Department of Materials Science and Engineering College of MaterialsXiamen University College of Civil Engineering Nantong University

The thin stiff films on pre-stretched compliant substrates can form wrinkles, which can be controlled in micro and nanoscale systems to generate smart structures. Recently, buck- led piezoelectric/ferroelectrie nanoribbons have been reported to show an enhancement in the piezoelectric effect and stretchability, which can be applied in energy harvesting devices, sensors and memory devices instead of polymeric polyvinylidine fluoride （PVDF）. This paper studies the buckling and post-buckling process of ferroelectric thin films bonded to the pre-stretched soft layer, which in turn lies on a rigid support. Nonlinear electromechanical equations for the buckling of thin piezoelectric plates are deduced and employed to model the ferroelectric film poled in the thickness direction. Two buckling modes are analyzed and discussed： partially de-adhered buck- ling and fully adhered buckling. Transition from one buckling mode to the other is predicted and the effect of piezoelectricity on the critical buckling condition of piezoelectric film is examined.

关键词： buckling ferroelectric films energy method variational method

Spatio-temporal evolution of Beijing 2003 SARS epidemic

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Science China Earth Sciences 2010年第7期53卷 1017-1028页

作者： CAO zhidong ZENG DaJun zheng XiaoLong WANG QuanYi WANG FeiYue WANG JinFeng WANG XiaoLi Key Laboratory of Complex Systems and Intelligence Science Institute of AutomationChinese Academy of SciencesBeijing 100190China Beijing Center for Disease Control and Prevention Beijing 100013China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Studying spatio-temporal evolution of epidemics can uncover important aspects of interaction among people, infectious diseases, and the environment, providing useful insights and modeling support to facilitate public health response and possibly prevention measures. This paper presents an empirical spatio-temporal analysis of epidemiological data concerning 2321 SARS-infected patients in Beijing in 2003. We mapped the SARS morbidity data with the spatial data resolution at the level of street and township. Two smoothing methods, Bayesian adjustment and spatial smoothing, were applied to identify the spatial risks and spatial transmission trends. Furthermore, we explored various spatial patterns and spatio-temporal evolution of Beijing 2003 SARS epidemic using spatial statistics such as Moran’s I and LISA. Part of this study is targeted at evaluating the effectiveness of public health control measures implemented during the SARS epidemic. The main findings are as follows. (1) The diffusion speed of SARS in the northwest-southeast direction is weaker than that in northeast-southwest direction. (2) SARS’s spread risk is positively spatially associated and the strength of this spatial association has experienced changes from weak to strong and then back to weak during the lifetime of the Beijing SARS epidemic. (3) Two spatial clusters of disease cases are identified: one in the city center and the other in the eastern suburban area. These two clusters followed different evolutionary paths but interacted with each other as well. (4) Although the government missed the opportunity to contain the early outbreak of SARS in March 2003, the response strategies implemented after the mid of April were effective. These response measures not only controlled the growth of the disease cases, but also mitigated the spatial diffusion.

关键词： severe acute respiratory syndrome (SARS) Beijing morbidity rate spatial analysis spatio-temporal evolution control measures

Effect of multi-channel discharge distribution on surface homogeneity in super-high-thickness WEDM

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Chinese Journal of Aeronautics 2023年第12期36卷 442-450页

作者： Cong DENG zhidong LIU Ming ZHANG College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Mechanical Engineering Suzhou University of Science and TechnologySuzhou 215101China

The multi-channel discharge phenomenon for super-high-thickness(more than 1000 mm)cutting is studied in high-speed wire electrical discharge machining(HS-WEDM).In super-high-thickness cutting,the length of the wire electrode with a poor conductor is longer in the machining area,so the resistance of wire electrode cannot be *** is found that the main reason for the formation of multi-channel discharge is that there is a high voltage between electrodes after dielectric breakdown due to the resistance characteristics of the wire *** the conventional discharge circuit is used for machining,the voltage between electrodes in the middle of the workpiece is much higher than that at the upper and lower ends,which is easier to generate multi-channel ***-channel discharge has the characteristic of dispersing discharge energy,which results in inhomogeneous surface roughness on the whole section of the *** improve the distribution characteristics of the inter-electrode voltage after dielectric breakdown,a novel discharge circuit is proposed,which gradually increases the inter-electrode voltage of discharge points distributed along the thickness direction of the workpiece,and significantly improves the formation probability of multi-channel discharge on the whole cutting surface.A super-high-thickness workpiece with a thickness of 1000 mm is used for continuous *** cutting speed of the two types of discharge circuit is basically the *** the surface roughness machined by the rear-end parallel circuit is reduced by 15.8%,and the surface homogeneity is greatly improved.

关键词： Inter-electrode voltage Multi-channel Super-high-thickness Surface quality WEDM