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Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

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National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan zhang zhiyong zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

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Influencing factors of the dynamic hysteresis in varying compliance vibrations of a ball bearing

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Science China(Technological Sciences) 2015年第5期58卷 775-782页

作者： zhang zhiyong CHEN YuShu LI ZhongGang Harbin Institute of Technology School of Astronautics

We focus on the hysteretic characteristics of the varying compliance(VC) principal resonance in a ball bearing. The branches of the periodic VC response are traced by the harmonic balance method and the alternating frequency/time domain technique(HB-AFT) embedding Arc-length continuation, and the stability of these solutions is investigated by using Floquet theory. We find that the resonant response displays a swallow-tail structure due to the coupling nonlinearities between the Hertzian contact and the bearing clearance, which differs from the soft hysteresis of the non-loss Hertzian contact resonances. Furthermore, we find that period-1 VC branch cannot completely characterize the response of the system for a large bearing clearance, because multiple instability regions may occur from the cyclic fold, the secondary Hopf bifurcations, supercritical and subcritical period doubling bifurcations, in which case co-existences of period-1, period-2, and even quasi-periodic VC motions emerge in the hysteretic resonant range.

关键词： resonant hysteresis supercritical bifurcation clearance branch continuation doubling compliance harmonic

Infrared modeling and imaging simulation of midcourse ballistic targets based on strap-down platform

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Journal of Systems Engineering and Electronics 2014年第5期25卷 776-785页

作者： Changzhen Qiu zhiyong zhang Huanzhang Lu Kaifeng zhang Science and Technology on Automatic Target Recognition Laboratory National University of Defense Technology

An infrared （IR） imaging simulation framework based on the strap-down platform is proposed for midcourse ballistic targets. It overcomes the shortcoming of the existing algorithms, which cannot simulate IR imaging from the entire midcourse process. The proposed framework includes three steps, target characteristic modeling, motion modeling, and imaging modeling. In imaging modeling, the staring focal plane is taken into account due to its wide employment. In order to obtain IR images of high fidelity, especially that the fluctuation of the target signal-to-noise ratio （SNR） is reasonably similar to the actual one, this paper proposes an improved IR imaging simulation method. The proposed method considers two critical factors of the pixel plane, occupy-empty ratio and defect elements, which affect the imaging of targets markedly but are neglected in previous work. Finally, the IR image sequence of high fidelity is obtained. And the correlative parameters of simulation can be set according to the given scene. Thus the generated images can satisfy the needs of algorithms validation for tracking and recognition.

关键词： strap-down platform midceurse ballistic target infrared (IR) staring focal plane.

More permutation polynomials with differential uniformity six

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Science China(Information Sciences) 2018年第3期61卷 223-225页

作者： Ziran TU Xiangyong ZENG zhiyong zhang School of Mathematics and Statistics Henan University of Science and Technology Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied Mathematics Hubei University School of Information Engineering Henan University of Science and Technology

Differential analysis is one of the most important attacks threatening iterated block *** resist against differential attacks[1],the multioutput Boolean functions used in designing Sboxes should have low differential *** a positive integer n,the lowest differential uniformity of the functions from the finite field F;(for a prime power q,F;denotes the finite field with

关键词： More permutation polynomials with differential uniformity six

First-principles study on electronic structures and optical properties of the single-walled (n, 0) ZnO nanotubes

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Science China(Physics,Mechanics & Astronomy) 2013年第4期56卷 706-712页

作者： DONG JunTang zhang FuChun zhang WeiHu zhang zhiyong College of Physics and Electronic Information Yanan University Information Science and Technology Institution Northwest University

Using the first-principles calculations, we studied the geometric structures, electronic structures and optical properties of the single-walled (n, 0) ZnO nanotubes (NTs). The calculated results show that all the bind energies of the single-walled (n,0) ZnO NTs are of negative values, which indicate that the ZnO NTs can exist stably as single-walled NTs. While the calculated results of electronic structure indicate that the single-walled (n,0) ZnO NTs are a type of direct wide band-gap semiconductor materials, the whole valence bands are spread and drift to low-energy direction with the increase of the NT diameter. The defect energy levels caused by quantum size and surface effects emerge on the top of the valence bands. Furthermore, the calculated results of optical properties reveal that the dielectric peaks have a blue shift and the edge of absorption band corresponds to ultraviolet band with the decrease of the NT diameter. The single-walled (n, 0) ZnO NTs can be applied to ultraviolet semiconductor systems.

关键词： ZnO first-principles nanotube properties

Improved incremental transfer matrix method for nonlinear rotor-bearing system

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Acta Mechanica Sinica 2020年第5期36卷 1119-1132,I0004页

作者： Yiheng Chen Xiaoting Rui zhiyong zhang Adeel Shehzad Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjing 210094China Department of Industrial and Manufacturing Engineering University of Engineering and TechnologyLahore 54000Pakistan

Rotor system supported by nonlinear bearing such as squeeze film damper(SFD)is widely used in practice owing to its wide range of damping capacity and simplicity in *** this paper,an improved and effective Incremental transfer matrix method(ITMM)is first presented by combining ITMM and fast Fourier transform(FFT).Afterwards this method is applied to calculate the dynamic characteristics of a Jeffcott rotor system with *** convergence dificulties incurred caused by strong nonlinearities of SFD has been dealt by adopting a control *** is found that for the more general boundary problems where the boundary conditions are not at input and output ends of a chain system,the supplementary equation is necessarily ***,the Floquet theory is used to analyze the stability and bifurcation type of the obtained periodic *** semi-analytical results,including the periodic solutions of the system,the bifurcation points and their types,are in good agreement with the numerical ***,the involution mechanism of the quasi-periodic and chaotic motions near the first-order translational mode and the second order bending mode of this system is also clarified by this method with the aid of Floquet theory.

关键词： Incremental transfer matrix method Squeeze film damper Jeffcott rotor system Bifurcation Nonlinear characteristics

Application in prestiction friction compensation for angular velocity loop of inertially stabilized platforms

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Chinese Journal of Aeronautics 2014年第3期27卷 655-662页

作者： zhang zhiyong Li Zhiqiang Zhou Qingkun zhang Lianchao Fan Dapeng College of Mechatronic Engineering and Automation National University of Defense Technology

Abstract To overcome the influence of the nonlinear friction on the gimbaled servo-system of an inertial stabilized platforms （ISPs） with DC motor direct-drive, the methods of modeling and compensation of the nonlinear friction are proposed. Firstly, the inapplicability of LuGre model when trying to interpret the backward angular displacement in the prestiction regime is observed experimentally and the reason is deduced theoretically. Then, based on the dynamic model of direct-drive ISPs, a modified LuGre model is proposed to describe the characteristic of the friction in the prestiction regime. Furthermore, the state switch condition of the three friction regimes including presliding, gross sliding and prestiction is presented. Finally, a composite compensation controller including a nonlinear friction observer and a feedforward compensator based on the novel LuGre model is designed to restrain the nonlinear friction and to improve the control precision. Experimental results indicate that compared with those of the conventional proportion-integrationdifferentiation （PID） control method and the PID plus LuGre model-based friction compensation method, the dwell-time has decreased from 0.2 s to almost 0 s, the position error decreased to 86.7% and the peak-to-peak value of position error decreased to 80% after the novel compensation controller is added. It concludes that the composite compensation controller can greatly improve the control precision of the dynamic sealed ISPs.

关键词： Closed loop control systems Friction compensation Inertially stabilized platforms Prestiction Stiction

‘Size effect’ related bending formability of thin-walled aluminum alloy tube

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Chinese Journal of Aeronautics 2013年第1期26卷 230-241页

作者： Li Heng Yang He zhang zhiyong Wang Zekang State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University

Aluminum alloy （Al-alloy） thin-walled （D/t ＆gt; 20, diameter D, wall thickness t） bent tubes have attracted increasing applications in many industries with mass quantities and diverse specifications due to satisfying high strength to weigh ratio requirements of product manufacturing. However, due to nonlinear nature of bending with coupling effects of multiple factors, the similarity theory seems not applicable and there occurs a challenge for efficient and reliable evaluation of the bending formability of thin-walled tube with various bending specifications. Considering the unequal deformation and three major instabilities, the bending formability of thin-walled Al-alloy tube in changing tube sizes such as D and t are clarified via both the analytical and FE modeling/ simulations. The experiments of rotary draw bending are conducted to validate the theoretical models and further confirm ＇size effect＇ related bending formability. The major results show that （1） The anti-wrinkling capability of tube decreases with the larger D and smaller t, and the effect significance of t is larger than that of D even under rigid supports; （2） The wall thinning increases with the larger D and smaller t, and this tendency becomes much more obvious under rigid supports; （3） The cross-section deformation increases with the larger D and smaller t according to the analytical model obtained intrinsic relationship, while this tendency becomes opposite due to the nonlinear role of mandrel die; （4） The size factor D/t can be used as a nondimensional index to evaluate both the bending formability regarding the wall thinning and cross-section deformation.

关键词： Al-alloy Bending formability Flattening Size effect Tube bending Wall thinning Wrinkling

Speeding up carbon nanotube integrated circuits through three-dimensional architecture

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Nano Research 2019年第8期12卷 1810-1816页

作者： Yunong Xie zhiyong zhang Donglai Zhong Lianmao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

Semiconducting carbon nanotube (CNT) field effect transistor (FET) is attractive for constructing three-dimensional (3D) integrated circuits (ICs) because of its low-temperature processes and low power dissipation. However, CNT based 3D ICs reported usually suffered from lower performance than that of monolayer CNT ICs. In this work, we develop a 3D IC technology through integrating multi-layer high performance CNT film FETs into one chip, and show that it promotes the operation speed of CNT based 3D ICs considerably. We also explore the advantage on ICs of 3D architecture, which brings 38% improvement on speed over two-dimensional (2D) one. Specially, we demonstrate the fabrication of 3D five-stage ring-oscillator circuits with an oscillation frequency of up to 680 MHz and stage delay of 0.15 ns, which represents the highest speed of 3D CNT-based ICs.

关键词： carbon nanotube nanoelectronics field-effect transistors three-dimensional (3D) integrated circuits ring oscillator