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Deep-learning-based nanowire detection in AFM images for automated nanomanipulation

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Nanotechnology and Precision Engineering 2021年第1期4卷 7-16页

作者： Huitian Bai sen wu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Atomic force microscope(AFM)-based nanomanipulation has been proved to be a possible method for assembling various nanoparticles into complex patterns and *** achieve efficient and fully automated nanomanipulation,nanoparticles on the substrate must be identified precisely and *** work focuses on an autodetection method for flexible nanowires using a deep learning *** instance segmentation network based on You Only Look Once version 3(YOLOv3)and a fully convolutional network(FCN)is applied to segment all movable nanowires in AFM *** with follow-up image morphology and fitting algorithms,this enables detection of postures and positions of nanowires at a high abstraction *** from these algorithms,our program is able to automatically detect nanowires of different morphologies with nanometer resolution and has over 90%reliability in the testing *** detection results are less affected by image complexity than the results of existing methods and demonstrate the good robustness of this algorithm.

关键词： Nanowire detection Instance segmentation YOLOv3 FCN Deep learning AFM

Electroless plating of Ni-Zn(Fe)-P alloy on carbon steel sheets

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中国有色金属学会会刊：英文版 2004年第z1期14卷 157-161页

作者： WANG sen-lin wu Hui-huang College of Materials Science and Engineering Huaqiao University Quanzhou 362021 China State Key Laboratory for Physical Chemistry of Solid Surface Department of ChemistryXiamen University Xiamen 361005 China State Key Laboratory for Physical Chemistry of Solid Surface Department of ChemistryXiamen University Xiamen 361005 China

The autocatalytic deposition of Ni-Zn(Fe)-P alloys were carried out on carbon steel sheets from bath containing nickel sulfate, zinc sulfate, sodium hypophosphite, sodium citrate and boric acid. The effects of pH and mole ratio of NiSO4/ZnSO4 on the deposition rate and the composition of deposit were studied. It is found that the presence of zinc sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the mole fraction of zinc in the deposits never reaches high value, which is less than 18.0%. The structure and surface morphology of Ni-Zn(Fe)-P coatings were charactered by XRD and SEM. The alloys plated at all conditions consist of amorphous phase coexisting with a crystalline cubic Ni phase. The surface morphology of coating is dependent on the deposition parameters.

关键词： electroless plating nickel zinc

Chaos Control and Bifurcation Behavior for a Sprott E System with Distributed Delay Feedback

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International Journal of Automation and computing 2015年第2期12卷 182-191页

作者： Chang-Jin Xu Yu-sen wu Guizhou Key Laboratory of Economics System Simulation Guizhou University of Finance and Economics School of Mathematics and Statistics Henan University of Science and Technology

In this paper, the problem of controlling chaos in a Sprott E system with distributed delay feedback is considered. By analyzing the associated characteristic transcendental equation, we focus on the local stability and Hopf bifurcation nature of the Sprott E system with distributed delay feedback. Some explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions are derived by using the normal form theory and center manifold theory. Numerical simulations for justifying the theoretical analysis are provided.

关键词： Sprott E system chaos control stability Hopf bifurcation distributed delay.

Chaos Control of a Chemical Chaotic System via Time-delayed Feedback Control Method

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International Journal of Automation and computing 2014年第4期11卷 392-398页

In this paper, the control of chemical chaotic dynamical system is investigated by time-delayed feedback control *** controllability and the stability of the equilibriums and local Hopf bifurcation of the system are verified. Some numerical simulations which show the effectiveness of the time-delayed feedback control method are provided.

关键词： Chemical system chaos stability Hopf bifurcation time delay

Bifurcation Control for a Duffing Oscillator with Delayed Velocity Feedback

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International Journal of Automation and computing 2016年第6期13卷 596-606页

作者： Chang-Jin Xu Yu-sen wu Guizhou Key Laboratory of Economics System Simulation Guizhou University of Finance and Economics Guiyang 550004 China School of Mathematics and Statistics Henan University of Science and Technology Luoyang 471023 China

In this paper, a Duffing oscillator model with delayed velocity feedback is considered. Applying the time delayed feedback control method and delayed differential equation theory, we establish some criteria which ensure the stability and the existence of Hopf bifurcation of the model. By choosing the delay as bifurcation parameter and analyzing the associated characteristic equation,the existence of bifurcation parameter point is determined. We found that if the time delay is chosen as a bifurcation parameter,Hopf bifurcation occurs when the time delay is changed through a series of critical values. Some numerical simulations show that the designed feedback controllers not only delay the onset of Hopf bifurcation, but also enlarge the stability region for the model.

关键词： bifurcation oscillator Feedback asymptotically dynamical Velocity enlarge perturbation imaginary unstable

Mlock:building delegable metadata service for the parallel file systems

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Science China(Information Sciences) 2015年第3期58卷 66-79页

作者： ZHANG Quan FENG Dan WANG Fang wu sen wuhan National Laboratory for Optoelectronics School of Computer Huazhong University of Science and Technology Information & Telecommunication Company State Grid Hubei Electric Power Company

The ever-growing demand for high performance computation calls for progressively larger parallel distributed file systems to match their *** file systems can achieve high performance for large I/O operations through distributing load across numerous data ***,they fail to provide quality service for applications pertaining to small *** this paper,we propose a delegable metadata service(DMS)for hiding latency of metadata accesses and optimizing small-file *** addition,four techniques have been designed to maintain consistency and efficiency in DMS:pre-allocate serial metahandles,directory-based metadata replacement,packing transaction operations and fine-grained lock *** schemes have been employed in Cappella parallel distributed file system,and various experiments complying with industrial standards have been conducted for evaluation of its *** results show that our design has achieved significant improvement in performance of both metadata operations and small-file ***,this scheme is widely applicable for integration within many other distributed file systems.

关键词： delegable metadata service metadata performance consistency small file parallel file system

Long-Term Sunspot Number Prediction based on EMD Analysis and AR Model

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Chinese Journal of Astronomy and Astrophysics 2008年第3期8卷 337-342页

作者： Tong Xu Jian wu Zhen-sen wu Qiang Li School of Science Xidian University Xi＇an 710071 China National Key Laboratory of Electromagnetic Environment China Research Institute of Radio Wave Propagation Beijing 102206 China IAP University of Rostock Schlosstr. 6 Kuehlungsbom 18225 Germany

The Empirical Mode Decomposition （EMD） and Auto-Regressive model （AR） are applied to a long-term prediction of sunspot numbers. With the sample data of sunspot numbers from 1848 to 1992, the method is evaluated by examining the measured data of the solar cycle 23 with the prediction： different time scale components are obtained by the EMD method and multi-step predicted values are combined to reconstruct the sunspot number time series. The result is remarkably good in comparison to the predictions made by the solar dynamo and precursor approaches for cycle 23. Sunspot numbers of the coming solar cycle 24 are obtained with the data from 1848 to 2007, the maximum amplitude of the next solar cycle is predicted to be about 112 in 2011-2012.

关键词： Sun sunspots- Sun activity

Effects of high-pressure rheo-squeeze casting on the Fe-rich phases and mechanical properties of Al-17Si-(1,1.5)Fe alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1018-1026页

作者： Chong Lin Shu-sen wu Shu-lin Lü Ping An He-bao wu State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Hubei Provincial Key Laboratory of Chemical Equipment Intensification and Intrinsic Safety Wuhan Institute of Technology

The effects of high pressure rheo-squeeze casting(HPRC) on the Fe-rich phases(FRPs) and mechanical properties of Al-17 Si-(1,1.5)Fe alloys were investigated. The alloy melts were first treated by ultrasonic vibration(UV) and then formed by high-pressure squeeze casting(HPSC). The FRPs in the as-cast HPSC Al-17 Si-1 Fe alloys only contained a long, needle-shaped β-Al5 Fe Si phase at 0 MPa. In addition to the β-Al5 Fe Si phase, the HPSC Al-17 Si-1.5 Fe alloy also contained the plate-shaped δ-Al4 Fe Si2 phase. A fine, block-shaped δ-Al4 Fe Si2 phase was formed in the Al-17 Si-1 Fe alloy treated by UV. The size of FRPs decreased with increasing pressure. After UV treatment, solidification under pressure led to further refinement of the FRPs. Considering alloy samples of the same composition, the ultimate tensile strength(UTS) of the HPRC samples was higher than that of the HPSC samples, and the UTS increased with increasing pressure. The UTS of the Al-17 Si-1 Fe alloy formed by HPSC exceeded that of the Al-17 Si-1.5 Fe alloy formed in the same manner under the same pressure. Conversely, the UTS of the Al-17 Si-1 Fe alloy formed by HPRC decreased to a value lower than that of the Al-17 Si-1.5 Fe alloy formed in the same manner.

关键词： high pressure rheo-squeeze casting Al-17Si-(1,1.5)Fe alloys Fe-rich phases mechanical properties

Microstructure,Mechanical Properties and Die-Filling Behavior of High-Performance Die-Cast Al-Mg-Si-Mn Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第11期28卷 1344-1353页

作者： Zu-Qi Hu Xin-Jian Zhang Shu-sen wu Institute of Materials China Academy of Engineering Physics State Key Lab of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology

This work aims to reveal the relationships between the microstructure, mechanical properties and flow behavior of die-casting AlMg5Si2Mn alloy. Results indicated that the microstructure of the die-cast AlMgsSi2Mn consists of α1-Al grains, fine-size α2-Al grains and （Al ＋ Mg2Si） eutectic. The surface layer observed has the thickness in a range of 120-135 μm, while an ellipse-like surface layer edge is observed in the corner of the plateqike sample. Tensile strength and elongation （3） of the specimens are slightly decreased along the die-filling direction due to the backflow of melt. Pure （Al ＋ Mg2Si） eutectic layer and ultra-fine-size α2-Al grains observed are around the overflow channels. Mass feeding is predominantly responsible for the superior mechanical properties of the round bars as compared to those of plate-like samples.

关键词： High-pressure die casting Aluminum alloy Microstructure segregations Mechanicalproperties Die-filling behavior Numerical simulation