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arXiv 2024年

作者： Shang, Linbo Zhang, Zhichao School of Mathematics and Statistics Nanjing University of Information Science and Technology Nanjing210044 China Key Laboratory of System Control and Information Processing Ministry of Education Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of Computational Science and Application of Hainan Province Hainan Normal University Haikou571158 China Key Laboratory of Numerical Simulation of Sichuan Provincial Universities School of Mathematics and Information Sciences Neijiang Normal University Neijiang641000 China

Vertex-frequency analysis, particularly the windowed graph Fourier transform (WGFT), is a significant challenge in graph signal processing. Tight frame theories is known for its low computational complexity in signal reconstruction, while fractional order methods shine at unveil more detailed structural characteristics of graph signals. In the graph fractional Fourier domain, we introduce multi-windowed graph fractional Fourier frames (MWGFRFF) to facilitate the construction of tight frames. This leads to developing the multi-windowed graph fractional Fourier transform (MWGFRFT), enabling novel vertex-frequency analysis methods. A reconstruction formula is derived, along with results concerning dual and tight frames. To enhance computational efficiency, a fast MWGFRFT (FMWGFRFT) algorithm is proposed. Furthermore, we define shift multi-windowed graph fractional Fourier frames (SMWGFRFF) and their associated transform (SMWGFRFT), exploring their dual and tight frames. Experimental results indicate that FMWGFRFT and SMWGFRFT excel in extracting vertex-frequency features in the graph fractional Fourier domain, with their combined use optimizing analytical performance. applications in signal anomaly detection demonstrate the advantages of FMWGFRFT. Copyright © 2024, The Authors. All rights reserved.

关键词： Frequency domain analysis

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Nanozymes with Antioxidant Enzyme-Like Activities Elevate Alcohol Production by Scavenging Reactive Oxygen Species in Saccharomyces Cerevisiae

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SSRN 2023年

作者： Qiao, Cailin Wang, Xinrou Gao, Yuwei Ma, Yi Luo, Huibo Zhang, Suyi Huo, Danqun Hou, Changjun Key Laboratory for Biorheological Science and Technology of Ministry of Education Bioengineering College of Chongqing University Chongqing400044 China Liquor Making Biology Technology Application of Key Laboratory of Sichuan Province College of Bioengineering Sichuan University of Science and Engineering 188 University Town Yibin644000 China National Engineering Research Center of Solid-State Brewing Luzhou Laojiao Group Co. Ltd. Luzhou646000 China

A novel approach was proposed to scavenge reactive oxygen species (ROS) in the fermentation environment by utilizing nanozymes with antioxidant enzyme-like activities to promote the growth of Saccharomyces cerevisiae (S. cerevisiae) cells and alcohol yield. The nanozymes (FeCo-PBA NPs, FeCo@CN, CoSO PNCs, and FeN3P-SAzyme) mimicked the activities of peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), and possessed low biotoxicity at low concentration (50 µg mL-1), except for the mild toxicity of CoSO PNCs. In the environmental stress simulated by IC50 concentration H2O2 in yeast cells in industrial application, the nanozymes were effective in enhancing S. cerevisiae cell activity and inhibiting ROS. Results shown that 50 µg mL-1 of nanozymes improved ethanol yield by 18.434-54.745% and total alcohol by 20.721-63.239%. This strategy has great potential to play a positive role in improving alcohol production during the S. cerevisiae industrial fermentation. © 2023, The Authors. All rights reserved.

关键词： Yeast

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Mechanism of Local Electric Oxidation on Two-Dimensional MoS2 for Resistive Memory application

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SSRN 2024年

作者： Dong, Hui Mu, Junzheng Peng, Jinfeng Zheng, Xuejun Chu, Liang School of Electro-mechanical Engineering Guangdong University of Technology Guangzhou510006 China School of Electronics and Information Institute of Carbon Neutrality and New Energy Hangzhou Dianzi University Hangzhou310018 China School of Mechanical Engineering & Engineering Research Center of Complex Tracks Processing Technology and Equipment of MoE Key Laboratory of Welding Robot and Application Technology of Hunan Province Xiangtan University Xiangtan411105 China

The manipulation and mechanism of two-dimensional (2D) transition metal dichalcogenides (TMDs) by external electric field are extremely significant to the photoelectric properties for guiding their applications. Herein, the 2D MoS2 nanosheets were locally oxidated to form MoS2-MoO3 local heterojunctions by electric field from atomic force microscopy tip, which were further applied in mutilstate memristors for the proposal of NanoQR code. A modified thermal oxidation model has been derived through introducing Ohmic dissipation to reveal the mechanism of local electric oxidation on 2D MoS2. From current-voltage curves, the barrier height of MoS2 device showed an increase of 0.39 eV due to local oxidation after applying voltage for 480 s. Based on density-functional theory, the increase of barrier height was theoretical calculated as 0.38 eV between MoS2-MoS2 and MoS2-MoO3 supercells, supporting the formation of MoO3 under the local electric field. The manipulated 2D MoS2-MoO3 local heterojunctions were further applied as unprecedented mutilstate memory storage at the nanoscale, which induced the proposal of NanoQR code as strong-encryption information. The findings suggest a novel strategy on precisely controlling local electric oxidation on 2D TMDs to manipulate the properties for application of photoelectric memory nanodevices. © 2024, The Authors. All rights reserved.

关键词： Heterojunctions

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Medical image super-resolution algorithm based on multi-scale feature aggregation

Medical image super-resolution algorithm based on multi-scal...

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Medical Artificial Intelligence (MedAI), IEEE International Conference on

作者： Xinyu Han Xun Gong School of Computing and Artificial Intelligence Southwest Jiaotong University Chengdu China Engineering Research Center of Sustainable Urban Intelligent Transportation Ministry of Education Chengdu China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Southwest Jiaotong University Chengdu China Manufacturing Industry Chains Collaboration and InformationSupport Technology Key Laboratory of Sichuan Province Southwest Jiaotong University Chengdu China

ISBN: (数字)9798350377613

ISBN: (纸本)9798350377620

Ultrasound images are vital for medical diagnostics but often suffer from information loss and blurred details due to limitations in imaging systems and sensor technologies. Many researchers have proposed super-resolution algorithms to enhance medical images. But existing super-resolution methods struggle with the uneven distribution of noise and clarity. To address this, we propose a super-resolution algorithm for medical images based on multi-scale feature aggregation Leveraging the architecture of Unet as our primary framework, our method enhances output details through multi-scale hole convolutions. Taking into consideration the characteristics of ultrasonic images, we propose a frequency domain-based module to enhances edge information while effectively denoising the image. Furthermore, to improve the quality of the output images, we introduce an image processing module grounded in global information. The module ensures clarity while considering the overarching context, thereby preserving global consistency and enhancing output quality. We experiment on three datasets to demonstrate the effectiveness of our model. Additionally, significant improvements in medical image segmentation are observed, proving the practicability of our proposed approach.

关键词： Image segmentation Ultrasonic imaging Image edge detection Frequency-domain analysis Superresolution Noise reduction Noise Medical diagnosis Artificial intelligence Medical diagnostic imaging

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A Dual-Functional Single-Atom Fe Nanozyme-Based Sensitive Colorimetric Sensor for Tannins Quantification in Brandy

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SSRN 2023年

作者： Hou, Changjun Wang, Xinrou Liu, Huan Qiao, Cailin Ma, Yi Luo, Huibo Huo, Danqun Key Laboratory for Biorheological Science and Technology of Ministry of Education Bioengineering College of Chongqing University Chongqing400044 China Chongqing Institute for Food and Drug Control Chongqing401121 China Liquor Making Biology Technology Application of Key Laboratory of Sichuan Province College of Bioengineering Sichuan University of Science and Engineering 188 University Town Yi bin644000 China Chongqing Key Laboratory of Bio-perception & Intelligent Information Processing School of Microelectronics and Communication Engineering Chongqing University Chongqing400044 China

Detection of tannins can be utilized as an approach for regulating food quality. Herein, a single-atom Fe nanozyme (Fe@CN-20)-based sensitive colorimetric sensor for tannins was initially developed. Fe@CN-20 had both laccase-like and oxidase-like activities, and has a high affinity for TMB with a Km value of 6.191×10-7 M. Therefore, the Fe@CN-20/TMB system can be sensitive to tannic acid due to the fact that tannins are easily oxidized. The linear range was 5 - 100 mg/L, and the detection limit was 0.13 mg/L (S/N=3). The entire testing process takes approximately 30 minutes. The sensing platform was further successfully utilized for quantifying tannins in five different brands of brandy. The sensing platform is characterized by great environmental stability, recyclability, remarkable sensitivity, and stability, all of which demonstrate its immense potential for rapid on-site detection of tannins. © 2023, The Authors. All rights reserved.

关键词： Tannins

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A Hybrid Excitation Method of Finite-gap Port Model in SIE for Electromagnetic Radiation Analysis

A Hybrid Excitation Method of Finite-gap Port Model in SIE f...

引用

Progress in Electromagnetic Research Symposium (PIERS)

作者： Zi-Qiang Wu Qiang-Ming Cai Xin Cao Longjian Zhou Haoran Li Zhen-Yong Du Yixiang Li Yuyu Zhu Yu-Teng Zheng Bo Pu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China Chengdu Juji Millimeter Wave Technology Co. Ltd. Chengdu China DeTooLIC Technology Co. Ltd. Ningbo China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

In this paper, a finite-gap port model, i.e., combining the current source with the voltage source in surface integral equation (SIE) is proposed to solve the electromagnetic radiation problem. For this model, a small gap region in the domain of analysis is identified as a two-terminal port and the fields in the gap are linked to the voltage or current definition. Two conditions must be enforced. One is the line integral of the electric field along straight paths in the gap are equal to the port voltage. The other is the current conducted into/out of the gap region is identical and equal in magnitude to the port current. The port model is implemented by modifying the traditional method of moments (MoM) solution to use a novel divergence-conforming testing function at the gap as well as half-RWG basis functions connected across the gap. And the half-RWG basis functions are defined on the opposite edge triangles at the two-terminal. Compared to the traditional delta-gap voltage sources with RWG basis functions defined in a pair of triangles, this finite-gap port model with new test functions removes the connecting patch between two terminals, which leads to high solution accuracy to calculate the port parameters of microstrip. When the traditional excitation is used to solve radiation problems with multi-port structures, the same type of excitation source for each port, either voltage or current sources are often chosen. However, in the practical engineering of antenna radiation, the voltage and current sources are often all added to excite antennas. In additional, it is also required to add the simultaneous excitation of multiple current and voltage sources into the ports of interconnection and packaging circuit simulation. To solve this problem, a hybrid excitation method of finite-gap port model with multiple current and voltage sources is combined in SIE. Several numerical results are further provided to demonstrate the validity and efficiency of this proposed met

关键词： Solid modeling Analytical models Integral equations Voltage Electromagnetic radiation Mathematical models Numerical models

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Modeling of Planar Transformers Based on PEEC Method

Modeling of Planar Transformers Based on PEEC Method

引用

Progress in Electromagnetic Research Symposium (PIERS)

作者： Ming-Jun Li Qiang-Ming Cai Tao Zhou Yu Tang Xin Cao Longjian Zhou Haoran Li Zhen-Yong Du Yixiang Li Yuyu Zhu Bo Pu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China Chengdu Juji Millimeter Wave Technology Co. Ltd. Chengdu China DeTooLIC Technology Co. Ltd. Ningbo China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

Accurate parasitic extraction of the planar transformers includes the modeling of magnetic components and the complicated printed circuit boards (PCB) structures. In this paper, a volume-based partial element equivalent circuit (PEEC) method is used to accurately characterize the resistance, inductance, and the loss caused by the magnetic components. The tetrahedral grids are used to provides a proper approximation for the via, slotted planes and the package structure, which also allows the accurate modeling of the copper losses at low frequencies. Moreover, the excitation can be flexible assigned over the structures due to the interpretation of the model circuitization. Finally, the algorithm is applied to extract parameters of a typical planar transformer and compared for accuracy with commercial software to demonstrate the feasibility of the method. The relative error within the relevant frequency range, when compared to Maxwell, is less than 10%.

关键词： Accuracy Printed circuits Transformers Conductors Magnetic materials Numerical models Integrated circuit modeling

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Microstrip Ultra-wideband Omnidirectional Vertically Polarized Antenna

Microstrip Ultra-wideband Omnidirectional Vertically Polariz...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Chao Zou Longjian Zhou Qiang-Ming Cai Xin Cao Haoran Li Zhen-Yong Du Yixiang Li Yuyu Zhu Yu-Teng Zheng Bo Pu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China Chengdu Juji Millimeter Wave Technology Co. Ltd. Chengdu China DeTooLIC Technology Co. Ltd. Ningbo China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

A microstrip ultra-wideband omnidirectional vertical polarization antenna is designed. The antenna consists of an elliptical ground, a metal fixator, a radome, a feed structure, and a radiator. Specifically, the relative dielectric constant of the antenna substrate is 4.4, the antenna substrate is fixed by a metal fixator and perpendicular to the metal base, On one side of the substrate, a slot is etched on the microstrip patch. On the opposite side of the substrate, a U-shaped microstrip structure is designed to feed the slot. A radome is added to the outside of the antenna, and the profile of the radome in the horizontal plane is elliptical. The overall streamlined structure of the radome makes the antenna applicable to aircraft, unmanned aerial vehicles, and other carriers. The size of the radome is 142.00 mm × 62 mm × 146.33 mm. The simulation results show that when the reflection coefficient is less than −10 dB, the bandwidth coverage is 0.69 ∼ 1.31 GHz. The relative bandwidth reaches 47.3%. The gain is relatively flat and greater than 3 dBi in the passband. The thickness of the substrate is only 1.6 mm. The antenna size is 0.270λ min × 0.246λ min , where λ min is the free-space wavelength at the lowest frequency of the operating band. The antenna has a low manufacturing cost and is suitable for a variety of broadband applications.

关键词： Slot antennas Simulation Metals Microstrip antennas Bandwidth Ultra wideband antennas Radomes

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A VIE-PEEC Method with Prism and Tetrahedron Mesh for Circuit Parameters Extraction from Complex Packaging Structures

A VIE-PEEC Method with Prism and Tetrahedron Mesh for Circui...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Wei Yang Qiang-Ming Cai Feng Guo Yu Tang Tao Zhou Xin Cao Longjian Zhou Haoran Li Zhen-Yong Du Yixiang Li Yuyu Zhu Bo Pu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China Chengdu Juji Millimeter Wave Technology Co. Ltd. Chengdu China DeTooLIC Technology Co. Ltd. Ningbo China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

This paper presents a novel solution of the partial element equivalent circuit (PEEC) method for method of moments of volume integral equation (VIE), which is developed for static direct-current (DC) simulation composite with conductive materials in packaging structures. In the proposed method, it utilizes tetrahedral and prism elements for geometric modeling, and the SWG basis function, simplified prism vector (SPV) basis functions and the connected SWG-SPV basis functions for volume current modeling. Then, a modified nodal analysis (MNA) equation matrix based on Kirchhoff laws is obtained and the massively parallel sparse direct solver (MUMPS) is adopted to solve the MNA equation. Numerical results are provided to demonstrate the accuracy, efficiency, and flexibility of the proposed method.

关键词： Solid modeling Accuracy Memory management Packaging Vectors Numerical models Sparse matrices

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L/C Dual Band Vertical Polarized Shared-aperture Antenna

L/C Dual Band Vertical Polarized Shared-aperture Antenna

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Hailing Zhao Chao Zou Longjian Zhou Qiang-Ming Cai Xin Cao Haoran Li Zhen-Yong Du Yixiang Li Yuyu Zhu Yu-Teng Zheng Bo Pu Jun Fan School of Information Engineering Southwest University of Science and Technology Mianyang China Robot Technology Used for Special Environment Key Laboratory of Sichuan Province Mianyang China Tianfu Institute of Research and Innovation Southwest University of Science and Technology (SWUST-TIRI) China Chengdu Juji Millimeter Wave Technology Co. Ltd. Chengdu China DeTooLIC Technology Co. Ltd. Ningbo China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

A low profile broadband shared-aperture antenna with vertical polarization and omnidirectional radiation pattern is proposed to cover some emerging wireless communication applications. For the L-band monocone antenna three copper bars are utilized to short the monocone at the edge to lower the minimum operating frequency. For the C-band antenna, the operating bandwidth is broadened by loading a coupling ring on the circular patch which is fed at the center. The C-band antenna is vertically placed on the top of the monocone antenna to achieve a common aperture design. The presented design combines the benefits of low-profile and broad bandwidth of the inverted hat monopole. The simulation results show that the impedance bandwidth of 95% (1.05GHz ~ 2GHz) and 43.3% (5.63GHz ~ 7.36GHz) are achieved for the antenna operating in L and C frequency bands respectively. It is also exhibits that good impedance matching and radiation pattern in the two frequency bands.

关键词： Wireless communication Surface impedance C-band Simulation Loading Dual band Bandwidth

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