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Iterative learning based fault detection and estimation in nonlinear systems

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Journal of Systems Engineering and Electronics 2012年第3期23卷 419-424页

作者： Wei Cao Wang Cong ming sun College of Automation Harbin Engineering University Harbin 150001 E R. China College of Computer and Control Engineering Qiqihar University Qiqihar 161006 E R. China

Aiming at a class of nonlinear systems that contains faults, a novel iterative learning scheme is applied to fault detec- tion, and a novel algorithm of fault detection and estimation is proposed. This algorithm first constructs residual signals by the output of the practical system and the output of the designed fault tracking estimator, and then uses the residuals and the difference- value signal of the adjacent two residuals to gradually revise the introduced virtual faults, which can cause the virtual faults to close to the practical faults in systems, thereby achieving the goal of fault detection for systems. This algorithm not only makes full use of the existing valid information of systems and has a faster tracking con- vergent speed than the proportional-type （P-type） algorithm, but also calculates more simply than the proportional-derivative-type （PD-type） algorithm and avoids the unstable effects of differential operations in the system. The final simulation results prove the validity of the proposed algorithm.

关键词： iterative learning nonlinear system fault detection fault estimation.

Theoretical Study of Decomposition Pathways for Rare-gas-containing Compounds HRgX (Rg = He, Ne, Ar, Kr; X = Cl, Br)

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Chinese Journal of Structural Chemistry 2005年第12期24卷 1445-1451页

作者： AI Chun-zhi sun Ren-An YAN Jie College of Chemistry and Chemical Engineering Liaoning normal university Dalian 116029 China

Eight species, HRgX （Rg = He, Ne, Ar, Kr; X = Cl, Br）, are predicted to have bending transition states at B3PW91/AUG-cc-PVTZ level, leading to 2-body decomposition pathway like H-Rg-X→Rg＋HX. The reaction path has been obtained with Intricate Reaction Coordinates （IRC） method on identical theoretical level. Additionally, the linear transition states of HArCl, HArBr, HKrCl and HKrBr were obtained at MP2/6-311 ＋＋G （2d, 2p） level, resulting in 3-body dissociation channel as H-Rg-X→H ＋ Rg＋ X.

关键词： decomposition pathway transition state IRC energy barrier

Improvement of photocatalytic activity of high specific surface area graphitic carbon nitride by loading a co-catalyst

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Rare Metals 2019年第5期38卷 468-474页

作者： Ye Chen Naoya Murakami Hai-Yan Chen Jia sun Qi-Tao Zhang zhi-Feng Wang Teruhisa Ohno ming Zhang Department of Materials Science Faculty of EngineeringKyushu Institute of TechnologyKitakyushu 8048550Japan School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Yangzhou Polytechnic Institute Yangzhou 225127.China Japan Science and Technology Agency Kawaguchi 3320012Japan

Graphitic carbon nitride(g-C3N4)was synthesized by heating melamine and was then treated with sodium hydroxide solution under a hydrothermal condition to obtain g-C3N4 with a large specific surface area(HSSA).HSSA shows higher photocatalytic activity for decomposition of acetaldehyde than that of original *** was modified with RuO2 as a co-catalyst by the impregnation *** loaded with 0.05 wt%RuO2 shows the highest photocatalytic activity for acetaldehyde decomposition under visible light(k=455 nm).

关键词： Graphitic carbon nitride Organic decomposition Co-catalyst Visible light

A mechanical reinforced and antifreezing polyacrylate hydrogel electrolyte for high-performance zinc-ion batteries

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Nano Research 2025年第1期18卷 341-350页

作者： Zili Zhang Ruolin Wang Hongfei Lu Di Zhang Yu Zhao Jing Xu Bin sun zhi-Min Dang Yang Jin School of Electrical and Information Engineering Zheng Zhou UniversityZhengzhou 450001China State Key Lab of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

The operation of aqueous zinc-ion batteries in flexible energy storage field is plagued by the uncontrollable growth of Zn-dendrite and inevitable freeze of water below 0 ℃.Therefore,it is necessary to design a hydrogel electrolyte with good mechanical property and freezing resistance to uniform the Zn-deposition and resist flexibility loss at low *** find that the mechanical property(strength and toughness)of hydrogel electrolyte has a significant impact on the suppression of dendrite growth and the uniform deposition of zinc ***,a polyacrylate hydrogel is prepared in one step by ultraviolet(UV)curing method with Zn(CF_(3)SO_(3))_(2)salt and polyvinyl alcohol(PVA)addition to increase the antifreezing ability and mechanical *** adsorption of water molecules by 2-hydroxyethyl acrylate(HEA)and PVA reduces the freezing point of the hydrogel,which is beneficial for enhancing the electrochemical stability at low *** this basis,the Zn-symmetrical battery with hydrogel electrolyte has a long lifespan of 4710 h at 0.5 mA·cm^(-2)and 0.5 mAh·cm^(-2)at room ***,the hydrogel electrolyte exhibits an outstanding stability at low temperature of^(-2)0 ℃,the lifespan of symmetrical battery reaches to 4000 h at 0.5 mA·cm^(-2)and 0.5 mAh·cm^(-2).The assembled full cell with NaV3O8·1.5H_(2)O(NVO)cathode and hydrogel electrolyte possesses a high capacity retention ratio of 77%after 10,000 cycles at^(-2)0 ℃.The flexible cell can power light-emitting diode(LED)lamp under bending,warping and cutting without liquid leakage and an electronic watch at the operating temperature of^(-2)0 ℃.

关键词： zinc ion battery hydrogel electrolyte mechanical enhancement freezing resistance

Boosting stability of inverted perovskite solar cells with magnetron-sputtered molybdenum rear electrodes

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Rare Metals 2023年第11期42卷 3741-3754页

作者： Zhao-Yi Jiang ming Pan Fu-Meng Ren Rui Chen Zhen-Xing sun zhi-Chun Yang Zong-Hao Liu Wei Chen Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China Optics Valley Laboratory Hubei430074China C Innovation Laboratory Contemporary Amperex Technology Ltd.Ningde352100China State Key Lab of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan030006China

Perovskite solar cells(PSCs)have attracted widespread attention because of their remarkable efficiency,low cost,and ease of ***,the operational stability of the PSCs still suffers from the corrosion of metal electrodes induced by metal-halide ***,we propose a feasible strategy for improving the stability of inverted PSCs by using magnetron-sputtered Mo rear *** with a bismuth(Bi)buffer layer prepared by thermal evaporation,the damage from the magnetron sputtering process toward the underlayers can be effectively ***,based on the Bi+Mo bilayer electrode,the inverted PSCs with a NiMgLiO hole transport layer exhibited a power conversion efficiency(PCE)of 18.82%.In addition to their excellent stability at high temperatures,compact Mo films can inhibit the decomposition of Perovskite(Pvk)films in the *** PSCs with the Bi/Mo bilayer electrode maintained 97.9%of its initial efficiency,showing better stability than PSCs with the traditional Ag electrode after aging for 3000 h under continuous light illumination.

关键词： Perovskite solar cells(PSCs) Magnetron sputtering Rear electrodes Molybdenum Stability

Thrust Vectoring of a Continuous Rotating Detonation Engine by Changing the Local Injection Pressure

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Chinese Physics Letters 2011年第9期28卷 182-185页

作者： LIU Shi-Jie LIN zhi-Yong sun ming-Bo LIU Wei-Dong Science and Technology on Scramjet Lab National University of Defense TechnologyChangsha 410073

The thrust vectoring ability of a continuous rotating detonation engine is numerically investigated,which is realized via increasing local injection stagnation pressure of half of the simulation domain compared to the other *** the homogeneous injection condition,both the flow-field structure and the detonation wave propagation process are *** to the same injection condition along the inlet boundary,the outlines of fresh gas zones at different moments are similar to each *** main flow-field features under thrust vectoring cases are similar to that under the baseline ***,due to the heterogeneous injection system,both the height of the fresh gas zone and the pressure value of the fresh gas in the high injection pressure zone are larger than that in the low injection pressure *** the average pressure in half of the engine is larger than that in the other half and the thrust vectoring adjustment is realized.

关键词： rotating inlet boundary

Structures and energetics of semicoherent interfaces of precipitates in hcp/bcc systems:A molecular dynamics study

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Journal of Materials Science & Technology 2021年第8期67卷 50-60页

作者： Jin-Yu Zhang Fu-zhi Dai zhi-Peng sun Wen-Zheng Zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China

α/β(hcp/bcc)interfaces are of great importance in the microstructure development and the mechanical properties of titanium and zirconium *** work contributes to the study of interface energetics and interfacial structures of the precipitate in the hcp/bcc system based on a simulation study using molecular statics(MS)and molecular dynamics(MD).The input orientation relationship(OR)was calculated based on the O-line *** on the energy of the interfaces containing the invariant line(IL),two preferred facets were determined by the Wulff construction,which explained the observed orientations of the habit plane(HP)and the side facet(SF).The deviation of the observed precipitate morphology from the equilibrium shape was discussed in terms of interface *** structures of the interfaces surrounding a three-dimensional(3 D)precipitate,including the preferred facets and the end face,were obtained at the atomic *** simulated dislocation structures and atomic structures in these interfaces are in good agreement with those of the experimental observations for Ti-Cr alloys.A method was suggested for modifying the O-cell structure with the guidance of the relaxed structure,yielding consistency between the calculated dislocation structure based on the generalized O-element approach and the simulation results.

关键词： Interface Misfit dislocation Precipitate

Nonlinear Forced Vibration of Cantilevered Pipes Conveying Fluid

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Acta Mechanica Solida Sinica 2018年第1期31卷 32-50页

作者： zhi-Yuan Liu Lin Wang Xi-Ping sun Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074 China Tianjin Research Institute Water Transport Engineering M.O.T. Test Detection Center of Water Transport Engineering Tianjin 300356 China

The nonlinear forced vibrations of a cantilevered pipe conveying fluid under base excitations are explored by means of the full nonlinear equation of motion, and the fourth- order Runge-Kutta integration algorithm is used as a numerical tool to solve the discretized equations. The self-excited vibration is briefly discussed first, focusing on the effect of flow velocity on the stability and post-flutter dynamical behavior of the pipe system with parameters close to those in previous experiments. Then, the nonlinear forced vibrations are examined using several concrete examples by means of frequency response diagrams and phase-plane plots. It shows that, at low flow velocity, the resonant amplitude near the first-mode natural frequency is larger than its counterpart near the second-mode natural frequency. The second-mode frequency response curve clearly displays a softening-type behavior with hysteresis phenomenon, while the first-mode frequency response curve almost maintains its neutrality. At moderate flow velocity, interestingly, the first-mode resonance response diminishes and the hysteresis phenomenon of the second-mode response disappears. At high flow velocity beyond the flutter threshold, the frequency response curve would exhibit a quenching-like behavior. When the excitation frequency is increased through the quenching point, the response of the pipe may shift from quasiperiodic to periodic. The results obtained in the present work highlight the dramatic influence of internal fluid flow on the nonlinear forced vibrations of slender Pipes.

关键词： Pipe conveying fluid Base excitation Nonlinear dynamics Primary resonance,Superharmonie resonance Forced vibration

Fatigue crack growth behavior of 2624-T39 aluminum alloy with different grain sizes

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Rare Metals 2021年第9期40卷 2523-2529页

作者： Guan Huang zhi-Hui Li Li-ming sun Xi-Wu Li Kai Wen Li-Zhen Yan Bai-Qing Xiong Yong-An Zhang State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China Northeast Light Alloy Co. Ltd.Harbin 150060China

The microstructure of 2624-T39 aluminum alloy was analyzed by means of metallographic(OM), scanning electron microscope(SEM) and transmission electron microscope(TEM). The effects of different microstructure characteristics on the tensile properties and fatigue crack growth rate of 2624-T39 aluminum alloy were *** showed that the grain size of the alloy was a typical fiber structure along the rolling direction, and the main second phase was the A_(l2)CuMg phase. The grain size of the alloy had an obvious influence on the fatigue crack growth rate, and the alloy showed a lower fatigue crack growth rate due to the larger grain size. The crack initiation zone on the fracture surface of alloys with lower fatigue crack growth rate was relatively rough, the crack propagation zone had obvious fatigue striations, and the transient fracture zone had a large number of smaller dimples.

关键词： 2624-T39 aluminum alloy Grain size Fatigue crack growth rate Fatigue fracture morphology