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Structure patterns of one-step synthesis of CuNi nanopowders in air environment: Experiment and atomistic simulations

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Nano-Structures and Nano-Objects 2024年 40卷

作者： Romanovski, Valentin Sdobnyakov, Nickolay Kolosov, Andrey Savina, Kseniya Nepsha, Nikita Moskovskikh, Dmitry Dobryden, Illia Zhang, Zhaowei Beletskii, Evgenii Romanovskaia, Elena Department of Materials Science and Engineering University of Virginia Charlottesville 22904 VA United States Department of General Physics Tver State University Tver 170002 Russian Federation Science and Research Centre of Functional Nano-Ceramics National University of Science and Technology “MISIS” Lenin av. 4 Moscow 119049 Russian Federation KTH Royal Institute of Technology Department of Chemistry Division of Surface and Corrosion Science Drottning Kristinas väg 51 Stockholm SE-100 44 Sweden Oil Crops Research Institute of Chinese Academy of Agricultural Sciences Wuhan 430062 China Key Laboratory of Biology and Genetic Improvement of Oil Crops Key Laboratory of Detection for Mycotoxins National Reference Laboratory for Agricultural Testing Wuhan 430062 China Hubei Hongshan Laboratory Wuhan 430000 China Institute of Chemistry St. Petersburg University Universitetskaya Emb.7/9 St. Petersburg 199034 Russian Federation

A possibility for one-step synthesis of bimetallic CuNi nanopowders in a different ratio of Ni to Cu by solution combustion synthesis technique under normal air atmosphere without any post reduction is reported. The effect of different types of fuels like citric acid and glycine on the combustion process and characteristics of resultant solid products were investigated. XRD results showed the existing of CuNi as a main phase and small amounts of CuO and (Ni,Cu)₄N. Determined CuNi particle sizes were in the range of up to 50 nm. Computer simulation was performed using the molecular dynamics method for similar concentration compositions, but in size range of 4.5–5.5 nm, as a result of cooling the system from 1700 K to 300 K. In addition, two types of melting scenario of binary CuNi NPs were studied: 1) heterogeneous melting of monocrystalline Cu and Ni NPs;2) melting of the crystallization products of binary NPs. Melting temperatures weakly depend on the choice of the above-mentioned melting scenario. However, the nature of subsequent crystallization can be influenced by the initial energy of the system, which is higher for case 1. The characteristic temperatures of phase transitions of melting and crystallization are determined based on the analysis of hysteresis loops of the specific potential part of the internal energy of NPs. The patterns of atomic and structural segregation in binary CuNi NPs were studied. © 2024 Elsevier B.V.

关键词： CuNi nanoparticles Homogeneous composites Molecular dynamics simulation Segregation Solution combustion synthesis

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UWB SAR image segmentation algorithm based on polynomial analysis of statistical distribution

UWB SAR image segmentation algorithm based on polynomial ana...

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Asian and Pacific Conference on Synthetic Aperture Radar (APSAR)

作者： Wang Yuming Jin Tian Luo Chaopeng College of Information Science and Engineering Hunan Provincial Key Laboratory of Intelligent Computhing and Language Information Processing Science and Technology on Near-Surface Detection Laboratory Hunan Normal University Changsha R.P.China College of Electronic Science and Technology Science and Technology on Near-Surface Detection Laboratory National University of Defense Technology Changsha R.P.China Science and Technology on Near-Surface Detection Laboratory Wuxi China

ISBN: (数字)9781728129129

ISBN: (纸本)9781728129136

Aimed at the segmentation problem of ultrawideband synthetic aperture radar (UWB SAR) image, a novel algorithm based on polynomial analysis of statistical distribution is proposed in this letter. Firstly, we estimate the probability density function (PDF) for each pixel via sparse decomposition of which the dictionary consists of orthogonal polynomials (OP). Secondly, the weighting coefficients of corresponding OP are used to segment image using their maximum value. The experimental results validate the efficiency of this algorithm.

关键词： Image segmentation Probability density function Synthetic aperture radar Radar polarimetry Signal processing algorithms Scattering Statistical distributions

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Generative Adversarial Networks for Exo-atmospheric Infrared Objects Discrimination

Generative Adversarial Networks for Exo-atmospheric Infrared...

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Signal, Information and Data Processing (ICSIDP), IEEE International Conference on

作者： Dongya Wu Huanzhang Lu Huamin Tao Bendong Zhao Ming Zhao National University of Defense Technology Changsha China Science and Technology on Near-Surface Detection Laboratory Wuxi China

ISBN: (数字)9781728123455

ISBN: (纸本)9781728123462

External atmospheric infrared (IR) target recognition is an important research topic of space surveillance systems. The different micromotion states of the target result in respective features in the obtained sequence of IR radiation intensities, and such differences are difficult to visually describe and difficult to extract efficiently. Due to the difficulty of spatial experiments, the target sample data is very limited. In the case of limited labeled samples, there are few methods that can effectively classify time series effectively, resulting in low classification accuracy and difficulty in meeting practical application requirements. We use generative adversarial networks(GAN) for semi-supervised learning, combining neural network classifiers with adversarial generation models for the classification of infrared grayscale time series of spatial targets. The effective classification of the target is achieved with a small number of labeled target samples. The experiment proves the effectiveness of the method and the classification effect is better than other methods.

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Application of update lifting morphological wavelet and non-negative matrix factorization for wheeled and tracked vehicles classification

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IOP Conference Series: Earth and Environmental science 2021年第1期660卷

作者： Kai Ding Kai Du Xiaogang Qi Yuelin Xu Junqi Cui Science and Technology on Near –Surface Detection Laboratory Wuxi China 214035 31104 troops Nanjing China 210007 Xidian University Xi'an China 710071

This paper presents an available scheme based on update lifting morphological wavelet (ULMW) and Non-negative matrix factorization (NMF) for wheeled and tracked vehicles classification. The ULWM algorithm which utilizes the update operator, means the morphological filter to replace the linear filter can preserve the impulsive shape details in seismic signal. Meanwhile the NMF method can reduce the computation cost. The traditional linear wavelet analysis and statistical analysis are compared with the presented scheme. Experimental results demonstrate that the presented scheme achieves a promising performance on extracting impulsive features of seismic signal and recognizing ground moving target.

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A Closed-Form Localization Algorithm in Scan-Based Sonar

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Journal of Physics: Conference Series 2021年第1期1848卷

作者： Ping Sun Yingjiao Rong Ocean Exploration Technology Institute Co. Ltd. Wuxi Jiangsu 214035 China Science and Technology on Near-Surface Detection Laboratory Wuxi Jiangsu 214135 China

Multi-station TDOA positioning is a more accurate positioning method, which can locate the acoustic emitter by processing the arrival time of signals collected by three or more measuring stations. This paper presents a closed-form localization algorithm using the angle-of-arrival and difference time of scan time measurements from the scan-based sonar (SBS).The basic principle of multi station TDOA passive location is proposed. Location scheme based on the combination of different platforms is used. The basic principle of TDOA passive location is discussed, as well as the realization scheme of the main problems such as the synchronization of observation station and acoustic target, the selection of ground observation station, error correction and so on.

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Cascaded Sliding Window Based Real-Time 3D Region Proposal for Pedestrian detection*

Cascaded Sliding Window Based Real-Time 3D Region Proposal f...

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IEEE International Conference on Robotics and Biomimetics

作者： Jun Hu Tao Wu Hao Fu Zhiyu Wang Kai Ding College of Intelligence Science and Technology National University of Defense Technology Changsha China Science and Technology on Near-Surface Detection Laboratory Wuxi China

Pedestrian detection is an indispensable technology for designing autonomous driving systems. This paper proposes a cascaded sliding window based real-time approach to generate 3D pedestrian proposals on point clouds only. After rasterizing the raw point cloud, a 3D sliding window is adopted to extract pedestrian candidates. Two features are proposed to improve the proposal performance. One is the central points density feature, which acts as a filter to speed up the process and reduce false alarms. The other is the location feature, including the density distribution and height difference distribution of the point cloud, which describes the profile and location of an object in a sliding window. The scores generated by this feature are then applied to non-maximum suppression (NMS) to remove sub-optimal boxes. Experiments on the KITTI 3D object detection benchmark show that our approach achieves state-of-the-art results among comparable methods, while maintaining the speed and accuracy trade-off.

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detection of UXO-like Targets with Portable Transient Electromagnetic System

Detection of UXO-like Targets with Portable Transient Electr...

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Jun Zhu Haiyang Zhang Yuelin Xu Yu Qiu Shuang Zhang Shudong Chen Science and Technology on Near-Surface Detection Laboratory Wuxi China College of Electronic Science and Engineering Jilin University Changchun China

With the advantages of strong anti-interference ability and high spatial resolution, electromagnetic induction (EMI) has proven to be successful in unexploded ordnance (UXO detection. Portable transient electromagnetic system can work in a variety of complex conditions where the large and heavy vehicular systems cannot be readily used. The detection of UXO-like targets with portable transient electromagnetic (TEM) system is discussed detailed in this paper. Firstly, with description of the single dipole model for UXO response approximation, the location and characteristic response extraction for UXO-like targets is talked with the DE algorithm. Then, the improved sensor of the portable TEM system with a single-layered transmitting coil and five 3-component receiving coils is introduced. The transmitting coil is constructed with a diameter, number of turns, and transmitting current of 0.5 m, 30, and 5 A, respectively. The receiving coil is constructed with a length, number of turns, and resonant frequency of 6 cm, 600, and 180 kHz, respectively. Finally, 12 UXOs and 6 harmless targets buried in the area of 10 m × 6 m at different depths in different orientations have been detected with the improved portable TEM system. Target location and characteristic response have been estimated by DE algorithm with the measured response. The experimental results show that the high-quality data provided by the improved portable TEM system combined with the DE algorithm based on the dipole model can locate and characterize the separated targets accurately. Most of the position errors are within 10cm in x position and 5cm in depths for separated buried targets. For the multiple-targets buried together, the system can still locate and characterize the targets even if the response of two targets overlaps.

关键词： Tensile stress Mathematical model Magnetic moments Perpendicular magnetic recording Magnetic fields Transient analysis

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Bucking coil used in unexploded ordnance detection with transient electromagnetic system

Bucking coil used in unexploded ordnance detection with tran...

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Hejun Jiang Xinqun Luan Jun Hao Shuang Zhang Shudong Chen Science and Technology on Near-Surface Detection Laboratory Wuxi China College of Electronic Science and Engineering Jilin University Changchun China

Off-time response is usually measured by transient electromagnetic (TEM) system to detect subsurface targets. Compared with off-time response, on-time response of TEM system is more sensitive to high-conductivity targets, such as UXOs. However, it is difficult to obtain on-time response directly due to the strong primary field response. The key problem for on-time measurement is to eliminate the primary field response. Bucking coil is adopted here to compensation the primary field of transmitter coil at receiving coil for on-time response measuring. Firstly, the structure of the sensor with transmitting coil, bucking coil, and receiving coil is presented. Then, the primary field of transmitting coil and bucking coil at the position of receiving coil is calculated theoretically. With the side length of transmitting coil, bucking coil and the receiving coil fixed, the number of turns for transmitting coil and bucking coil are optimized for the best compensation. Calculated results show that the best compensation effect can reach 0.53%. Finally, the sensor with a transmitting coil (constructed with a side length and number of turns of 96 cm and 30, respectively), a bucking coil (constructed with a side length and number of turns of 26 cm and 8, respectively), and a receiving coil (constructed with a side length of 6 cm) was built. Measured results show that the primary field response after compensation is no more than 1% of the original response, and the maximum amplitude is only 0.4V. The on-time response of targets can be accurately recorded.

关键词： Geophysical measurements Magnetic field measurement Pollution measurement Current measurement Magnetic flux Transient analysis

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Location of Buried Target with Method of Auxiliary Sources

Location of Buried Target with Method of Auxiliary Sources

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Shan Liang Shuang Zhang Shudong Chen Zhaohe Liu College of Electronic Science and Engineering Jilin University Changchun China Science and Technology on Near-Surface Detection Laboratory Wuxi China

It is a key problem to locate a buried target in UXO detection. The inversion algorithm based on the principle of least squares requires a large number of forward calculations to estimate the position of a target. The method of auxiliary sources (MAS) which can directly locate a UXO-like target is presented here without forward calculation. With a brief description of single dipole model for a UXO-like target, the basis of target location with magnetic field and scalar magnetic potential is deduced theoretically. Auxiliary sources made of elementary magnetic dipoles on a plane are applied to estimate the equivalent scalar magnetic potential from the measured magnetic field. Firstly, the moment of elementary magnetic dipoles is estimated by matching the measured magnetic field with the auxiliary sources modeled field. Then, the equivalent scalar magnetic potential is calculated with these elementary magnetic dipoles without a priori knowledge of the target's location. Finally, the position is calculated directly with the measured magnetic field and the equivalent scalar magnetic potential. The responses of four UXOs excited by a z-component square transmitting coil are recorded by a 9×9 3-component receiving coil array. With the auxiliary sources on a plane under the measurement grid, the equivalent scalar magnetic potential is calculated precisely. Experimental results show that the measured magnetic field matches well with the auxiliary sources modeled field, and the estimated positions of all targets are highly consistent with the measured ones. The horizontal error is within 2 cm, and the depth error is within 6 cm.

关键词： Magnetic field measurement Magnetic fields Position measurement Mathematical model Magnetometers Geophysical measurements Transient analysis

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UXO localization procedures applied to potable TEM sensor

UXO localization procedures applied to potable TEM sensor

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IEEE Advanced Information technology, Electronic and Automation Control Conference (IAEAC)

作者： Yu Qiu Shuang Zhang Shudong Chen Chaopeng Luo College of Electronic Science and Engineering Jilin University Changchun China Science and Technology on Near-Surface Detection Laboratory Wuxi China

Localization of unexploded ordnance (UXO) with transient electromagnetic (TEM) system is a principle and necessary problem in detection procedures, especially beset by low data diversity and high positioning uncertainty. In this paper, procedures for targets location are presented in detail with cued data collected by potable TEM sensor JPMD, which is designed to provide diverse time-domain data of high quality with one transmitter coil and five 3-component receiving coils. Based on the single dipole model, the target is located with the data collected at a single spatial point by the differential evolution (DE) optimization algorithm which can be subdivided into three steps. With the structure and parameters of JPMD sensors and data inversion process described briefly, a field test site of 5 m × 5 m measurement grid was conducted to present the specific UXO localization procedures at Jilin University. Results indicate that all the UXO-like targets can be detected distinctly with JPMD. The location of single object can be inversed rapid in tolerable error at one single point. For two objects with overlapping signals as one, the inverted horizontal position is basically in the middle of them and depth is a bit smaller than theory.

关键词： Data models Magnetic field measurement Electromagnetics Optimization Time measurement Mathematical model Linear programming

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