Article
Nanoscience & Nanotechnology
A. Kathirvel, K. N. Indu Krishna, R. Ganga, A. Uma Maheswari, M. Sivakumar
Summary: By doping Zr4+ ions, the structure and performance of lead-free ferroelectric thin films can be improved, and the leakage current can be reduced. Zr doping can also reduce the aging problem caused by oxygen vacancies and enhance the photoconductive properties.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Yutong Li, Gang Wang, Zehui Lin, Peijia Bai, Jiao Han, Mingwei Li, Duan Mao, Yiming Zeng
Summary: The influence of La doping on lead-free multiferroic Bi1-xLaxFeO3 ceramics has been investigated, showing that La doping causes structural distortion, changes in the generation of secondary phases, variations in grain size, and increase in carriers, thus affecting the dielectric, ferroelectric properties, and leakage current characteristics.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Ceramics
Arshid Mir, Khushboo Iqbal, S. Rubab, M. A. Shah
Summary: This paper describes a novel one-step anodization synthesis of Fe-doped TiO2 nanotubes and analyzes the effect of doping concentration on the morphology, structure, and composition of the prepared samples. The results showed the formation of anatase phase with Fe incorporation in the TiO2 lattice. The absorption spectra showed a red shift and the photocurrent density of Fe-doped samples was significantly higher than that of the pristine TiO2 sample, with the best results obtained from a sample doped at a level of 0.5%.
CERAMICS INTERNATIONAL
(2023)
Article
Spectroscopy
Junwei Hou, Tengze Xu, Yanbin Ning, Bingxuan Huang, Ye Yang, Qingyao Wang
Summary: Ti3+ self-doped TiO2-x nanotube arrays were prepared and characterized, showing high visible light response, photocurrent, and photoelectrocatalytic activities. The improved performance was attributed to the synergistic effect of narrowed energy gap and enhanced electron transportation, providing new opportunities for high-performance solar cells and photocatalysts.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2021)
Article
Nanoscience & Nanotechnology
Timofey Savchuk, Ilya Gavrilin, Elizaveta Konstantinova, Alexey Dronov, Roman Volkov, Nickolay Borgardt, Tomasz Maniecki, Sergey Gavrilov, Vladimir Zaitsev
Summary: A comparative study on the photocatalytic activity of TiO2 nanotubes arrays in gas-phase CO2 conversion to hydrocarbon products revealed that multi-walled nanotubes exhibit faster rates of methane and methanol production compared to single-walled nanotubes. EPR spectroscopy showed that Ti3+/oxygen vacancy centers are mainly located inside the outer layer of nanotubes, while carbon dangling bonds are observed on the surface of the inner layer, indicating the key role of carbon defects in photoinduced charge carrier accumulation.
Article
Chemistry, Multidisciplinary
Juan-Ru Huang, Wen-Xiong Shi, Shen-Yue Xu, Hao Luo, Jiangwei Zhang, Tong-Bu Lu, Zhi-Ming Zhang
Summary: By implanting single atom Fe into nanotubes, controllable production of methanol and CO/CH4 can be achieved. In pure water, the methanol yield reaches 154.20 mu mol g(cat)(-1) h(-1) with 98.90% selectivity, while the yield and selectivity of CO/CH4 are also high when the catalyst is outside water. This research provides new insight for water-mediated CO2 photoreduction.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Anton Tuluk, Tadhg Mahon, Sybrand van der Zwaag, Pim Groen
Summary: The study found that combining ceramic particles with a non-conductive polymer can improve the poling efficiency and piezoelectric constant values of BiFeO3, leading to higher piezoelectric performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
S. Q. Yin, J. Feng, Y. P. Zheng, Z. Y. Ren, L. F. He, H. N. Li, F. Yang, S. T. Dang, S. Y. Chen, Y. C. Hu, J. Shang, X. W. Wang
Summary: Energy storage ceramics are important materials used in high temperature-resistant dielectric pulse power systems. This study prepared BCZT-BFMT ceramics using the sol-gel method and solid phase method, and investigated the effects of different doping amounts on their energy storage performance. The results showed that the sample with 50% doping content exhibited better dielectric properties.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Physical
Farha Jabeen, Raza Shahid, M. Shahid Khan, Raghvendra Pandey
Summary: Lead-free 0.7BiFeO(3)-0.3BaT(i1-x)Mn(x)O(3) ceramics were prepared by adding MnO2 and their structural, spectral, electrical, magnetic, and piezoelectric properties were investigated. The results showed that the addition of MnO2 significantly enhanced the electrical and piezoelectric properties of the ceramics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Chemical
Dhurgham Khudhair, Julie Gaburro, Hoda Amani Hamedani, Anders Barlow, Hamid Garmestani, Asim Bhatti
Summary: Direct interaction with neuronal cells is crucial for understanding brain diseases and abnormalities. Vertically oriented TiO2 nanotube arrays with copper doping show superior electrochemical properties and biocompatibility, making them promising for neural interfacing applications. Optimization of nanotube arrays through doping can enhance functionality and structural properties, such as diameter and wall thickness, leading to improved performance.
Article
Environmental Sciences
Fan Zhang, Weilai Wang, Lei Xu, Chengzhi Zhou, Yanglong Sun, Junfeng Niu
Summary: The study successfully achieved electrochemical degradation of Ni-EDTA using ECR-TiO2 NTA electrode, with high removal efficiency and the main degradation pathway involving cleavage of the amine group within Ni-EDTA. Results demonstrate that ECR-TiO2 NTA has excellent efficiency in removing Ni-EDTA.
Article
Materials Science, Ceramics
Ao Zhou, Ruitong Chi, Rong Liu, Yingjie Shi, Zhixiao Zhang, Hongwei Che, Guangsuo Wang, Jingbo Mu, Yanming Wang, Xiaorong Zhang
Summary: In this study, Se doped nickel-cobalt sulfide (Se-NiCoS) nanotube arrays with three-dimensional (3D) networks were prepared and their enhanced electrochemical performance was observed. The doping of Se and the unique 3D network structure greatly improved the areal capacitance and cyclic stability of the nanotube arrays. Additionally, a hybrid supercapacitor assembled with Se-NiCoS nanotube arrays and carbon nanotubes exhibited high energy density.
CERAMICS INTERNATIONAL
(2022)
Article
Physics, Condensed Matter
Zarish Nazeer, Ismat Bibi, Farzana Majid, Shagufta Kamal, Aamir Ghafoor, Adnan Ali, Abida Kausar, Zainab M. Elqahtani, Norah Alwadai, Munawar Iqbal
Summary: A series of Ga and Sr doped bismuth ferrite (BiFeO3) was synthesized and characterized, showing improved photo-catalytic activity and stability. The material may find applications in high frequency devices and treatment of industrial wastes.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Weiwei Mao, Qifu Yao, Nanjing Liu, Huazhong Shu, Jiangwei Zhu, Yong Pu, Xing'ao Li
Summary: The study showed that doping with Ca element can significantly enhance the photovoltaic performance of BFO thin film, with notable improvement in Voc and Jsc.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Multidisciplinary Sciences
Timofey Savchuk, Ilya Gavrilin, Andrey Savitskiy, Alexey Dronov, Daria Dronova, Svetlana Pereverzeva, Andrey Tarhanov, Tomasz Maniecki, Sergey Gavrilov, Elizaveta Konstantinova
Summary: The influence of carbon content in symmetric TiO2 nanotube arrays on their photoelectrochemical properties and photocatalytic activity for CO2 conversion has been studied. Carbon-related defects accumulate electrons on the surface and promote CO2 conversion efficiency, but excessive carbon content causes instability in the process.
Article
Materials Science, Ceramics
Lei Liu, Zijian Zhou, Xiangkun Elvis Cao, Yue Zhou, Dejun Peng, Ying Liu, Xiaowei Liu, Minghou Xu
Summary: Many dopants have been explored to improve the heat storage performance and sintering resistance of Co3O4, but the performance of these materials is not comparable due to different synthesis methods and test conditions. This study systematically compared and screened nine dopants, including four unreported ones, under the same conditions. The results showed that Cu and Zr doping had the highest re-oxidation rate, while Si and Mg doping had adverse effects on the conversion rate. Cu-doped sample exhibited higher re-oxidation rate and energy density, while Zr-doped sample exhibited more stable cyclability.
CERAMICS INTERNATIONAL
(2023)
Article
Automation & Control Systems
Lei Liu, Yongxiong Liu, Lilin Zhou, Bo Wang, Zhongtao Cheng, Huijin Fan
Summary: In this paper, the application of active disturbance rejection control (ADRC) based on a neural network for the attitude control of a hypersonic vehicle (HV) with uncertain disturbances is investigated. The strong coupling of the HV poses challenges for separate ADRC design for each channel. A cascade active-rejection control scheme is proposed to mitigate this issue, using a Radial Basis Function (RBF) Neural Network instead of the Extended State Observer (ESO) in ADRC. The proposed NNESO-based cascade ADRC demonstrates effective disturbance resistance for HV control.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2023)
Article
Engineering, Electrical & Electronic
Yongjun Du, Yiwei Xu, Jingen Wu, Jiacheng Qiao, Zhiguang Wang, Zhongqiang Hu, Zhuangde Jiang, Ming Liu
Summary: This study presents the first VLF underwater communication system based on a pair of acoustically actuated magnetoelectric antennas. The feasibility of the ME antennas for portable underwater communication is confirmed through theoretical analysis, finite element simulation, and experimental verification.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Automation & Control Systems
Xiao Han, Lei Liu, Huijin Fan, Zhongtao Cheng
Summary: This paper investigates the robust approximate optimal control problem for air-breathing hypersonic vehicle (AHV) and proposed a robust approximate optimal controller based on adaptive dynamic programming (ADP). By input-output linearization and introducing auxiliary variables, the high-order nonlinear AHV dynamics are transformed to a second-order feedback decoupling model. The proposed controller considers both robustness and input cost, optimizes control actions, and avoids chattering. The use of a single critic network design ensures system stability and simplifies implementation. Simulation results demonstrate the effectiveness of the proposed scheme.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Automation & Control Systems
Hui Hu, Bo Wang, Lei Liu, Zhongtao Cheng
Summary: In this paper, a new adaptive time-varying barrier Lyapunov function (A-TBLF) is proposed for spacecrafts with adaptive time-varying state constraints. The A-TBLF method adapts the barrier in real-time to ensure convergence of the constrained state into a predefined domain. It also includes a barrier update restart scheme to prevent barrier violations. Additionally, a nonlinear margin function is introduced to avoid input saturation and a finite-time estimation adaptive observer chain is proposed for accurate control input design.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Automation & Control Systems
Xinpeng Fang, Huijin Fan, Wei Wang, Lei Liu, Bo Wang, Zhongtao Cheng
Summary: In this article, an adaptive finite-time fault-tolerant control (FTC) strategy is proposed for state tracking of uncertain systems subject to actuator faults and input saturation. The proposed control scheme effectively deals with the coupling of unknown model uncertainties and actuator faults using an adaptive mechanism based on a wisely chosen Lyapunov function. Simulation and comparison results in a flight control system show the effectiveness and advantages of the proposed control scheme.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2023)
Article
Automation & Control Systems
Huijin Fan, Xinpeng Fang, Wei Wang, Jiangshuai Huang, Lei Liu
Summary: This paper studies the fault-tolerant control problem for a class of nonlinear systems with uncertain parameters and unknown actuator failures. An adaptive fault-tolerant control scheme based on event-triggered strategy is proposed, and a set of event-triggering conditions are designed for both the controller and the parameter estimators. It has been proven that the closed-loop signals are globally uniformly bounded and the system output converges to a compact set. A modified fault-tolerant control scheme is also designed for the case with a finite number of failures, ensuring the asymptotic convergence of system states. The effectiveness of the proposed schemes is illustrated through a robot manipulator example.
Article
Automation & Control Systems
Wenzhe Fu, Lei Liu, Bo Wang, Zhongtao Cheng, Yongji Wang
Summary: This paper proposes a model predictive static programming (MPSP) based solution to the challenging problem of ascent energy management for hypersonic vehicles using solid rocket boosters. A Bezier spline guidance method is introduced to generate high-quality reference trajectories and improve the performance of MPSP. An online parameter estimation based on the extended Kalman filter is employed to address parametric uncertainties. Numerical simulations demonstrate the effectiveness and robustness of the proposed algorithm in guiding hypersonic vehicles to a given terminal state under uncertainties and outperforming existing methods.
INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING
(2023)
Article
Physics, Applied
Guohua Wu, Zhong Yu, Rongdi Guo, Zhiguang Wang, Hong Wang, Zhongqiang Hu, Ming Liu
Summary: To achieve compact and lightweight power conversion devices, MnZn ferrite doped with high-valent Sn4+ ions is used to manipulate electromagnetic properties and suppress high-frequency core losses. The Sn4+ ions mainly occupy grain boundaries rather than dissolving into the lattice, significantly impacting the electromagnetic properties. With increasing Sn substitution, initial permeability and saturation induction decrease monotonically. A Sn substitution content of 0.003 reduces core losses to 457 kW m(-3) at 3 MHz, 30 mT, and 25 degrees C, effectively suppressing eddy current loss and residual loss. The sample with Sn content of 0.003 demonstrates excellent overall electromagnetic properties, making it potentially useful in high-frequency transformers, converters, and power sources.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Aerospace
Gaoxiang Peng, Bo Wang, Lei Liu, Huijin Fan, Zhongtao Cheng
Summary: In this article, a real-time entry trajectory generation algorithm with modular policy is proposed to achieve adaptability to various missions. Deep reinforcement learning is utilized to train two modules, providing a reliable trajectory and solving state misalignment and contradiction.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Jingen Wu, Yongjun Du, Yiwei Xu, Jiacheng Qiao, Yuhan Qu, Zhiguang Wang, Shuxiang Dong, Zhongqiang Hu, Ming Liu
Summary: A face-shear type magnetoelectric (ME) sensor is demonstrated using a composite material of (PbMg0.33Nb0.67O3)(1-x)-(PbTiO3)(x) piezoelectric single crystal (PMN-PT) and Metglas amorphous alloy. The sensor is capable of detecting weak magnetic fields by inducing face-shear strain in PMN-PT through the magnetostriction of Metglas, resulting in the generation of an ME voltage.
IEEE SENSORS JOURNAL
(2023)
Article
Materials Science, Ceramics
Guohua Wu, Zhong Yu, Rongdi Guo, Zhiguang Wang, Hong Wang, Zhongqiang Hu, Ming Liu
Summary: This study investigates the relationship between domain morphology, dynamic magnetization behavior, and high-frequency core losses in MnZn ferrites by producing MnZn ferrites with different grain sizes through changing the sintering temperature. The results show that when the grain size approaches the critical size, the residual loss is effectively reduced, while an increase in grain size leads to a sharp increase in residual loss.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Engineering, Aerospace
Z. Y. Yin, B. Wang, R. T. Xiong, Z. Xiang, L. Liu, H. J. Fan, C. L. Xue
Summary: This paper investigates the constrained attitude control problem of hypersonic vehicles and proposes an improved prescribed performance dynamic surface control method. An adaptive scaling strategy is introduced to avoid state violation, and a nonlinear disturbance observer is used to compensate system disturbances. Numerical simulations demonstrate the effectiveness and superiority of the proposed method.
AERONAUTICAL JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Jiaming Liu, Mengmeng Guan, Yiwei Xu, Shuang Zhao, Wei Su, Cuiling Zhang, Zhiguang Wang, Xiaohui Zhang, Zhongqiang Hu, Zhuangde Jiang, Ming Liu
Summary: In this work, a new weak-current sensor module based on the tunneling magnetoresistive (TMR) effect was developed, which can accurately measure microamperes-level weak electric currents. The sensor has low noise, high sensitivity, and wide bandwidth, and performs well in both DC and AC current measurements. This sensor has significant potential for applications in industrial fields such as smart grids and green energy.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Chemistry, Physical
Jingen Wu, Zhongqiang Hu, Chaoyu Wu, Ming Ma, Xin He, Jiacheng Qiao, Zhiguang Wang, Shuxiang Dong, Ming Liu
Summary: This study proposes a method for observing thermal depolarization by examining the strain induced by 90-degree domain switching, and verifies the effectiveness of the method using tetragonal BiScO3-PbTiO3 (BS-PT) piezoelectric ceramic samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
