Article
Green & Sustainable Science & Technology
Herui Zhang, Weihong Guo
Summary: In this study, the acoustic emission (AE) characteristics of thermally damaged rock under load were investigated during deep resource exploitation. The results showed that the strength and AE energy of sandstone decreased gradually with increasing heating temperature. Frequency domain analysis revealed that the frequency and intensity of AE also exhibited a downward trend with temperature increase. Introducing multifractal theory provided new parameters for waveform analysis, which could be combined with frequency analysis to more accurately identify rock failure in engineering practice.
Article
Engineering, Multidisciplinary
Shan Yin, Dazhao Song, Jie Li, Xueqiu He, Liming Qiu, Quan Lou, Menghan Wei, Yang Liu
Summary: The HHT method is used to analyze and process the EMR waveform of coal failure process, effectively extracting the refined features of EMR waveform signal and improving the identification degree of the precursor characteristics of coal body instability. HHT method has an improved adaptability and superiority in revealing the characteristics of coal deformation and failure.
Article
Chemistry, Analytical
Jeongha An, Hyungin Ra, Changhyun Youn, Kiman Kim
Summary: This paper proposes underwater acoustic communication using a generalized sinusoidal frequency modulation (GSFM) waveform, showing better performance in multipath channels compared to conventional linear frequency modulation (LFM) waveform with chirp spread spectrum (CSS). Through simulations, lake trials, and sea trials, experiments demonstrated the superior performance of the proposed GSFM method over the traditional CSS method, with lower bit error rates and higher reliability.
Article
Computer Science, Information Systems
Leonardo Sandrolini, Andrea Mariscotti
Summary: Switched-mode power supplies (SMPSs) are a common source of unsymmetrical conducted emissions. This study explores the characteristics of SMPSs in both time and frequency domains, and identifies relevant phenomena and parameters choices. The findings are supported by a range of measured emission records.
News Item
Optics
Jeffrey Moses, Shu-Wei Huang
Summary: Coherent multi-octave mid-infrared waveforms can be generated and manipulated using cascaded intrapulse difference-frequency generation, providing absolute phase control and expanding the techniques available for arbitrary light-wave control.
Article
Engineering, Multidisciplinary
Quan Lou, Bing Jia, Xiang-yun Wan, Da-zhao Song, Li-ming Qiu, Yu-chen Ma, Xuan-xuan Qi
Summary: Uniaxial compression experiments were conducted on coal and rock samples to study the discrete characteristics of the instantaneous frequency of the electromagnetic radiation (EMR) waveform induced by their fracture. The EMR signals were filtered and de-noised using the empirical wavelet transform, and the time-frequency characteristics of the waveform were analyzed using the short-time Fourier transform. The results showed that the centroid frequency of 0-100 kHz is negatively correlated with the peak-to-peak values (Vpps), and the relationship between them follows a logarithmic function relation.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Acoustics
Bo Yan, Xiagui Pan, Ran Su, Chuanyu Wu
Summary: This study investigates the dynamics behavior of a tumbler on an arc surface. The results demonstrate the potential for designing low-frequency vibration devices and open up new possibilities for tumbler-inspired structures.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Orthopedics
Qingwen Yu, Zhirui Li, Jiantao Li, Qinghua Yu, Licheng Zhang, Daohong Liu, Mingzhu Zhang, Peifu Tang
Summary: Calcaneal fractures can cause numerous complications and have a poor prognosis. Understanding the relationship between the distribution of fracture lines and the internal structure of the calcaneus is important for improving treatment outcomes.
JOURNAL OF ORTHOPAEDIC SURGERY AND RESEARCH
(2022)
Article
Geochemistry & Geophysics
Zhaoqi Gao, Wei Yang, Chuang Li, Feipeng Li, Qingzhen Wang, Jicai Ding, Jinghuai Gao, Zongben Xu
Summary: In this article, a new nonlinear FWI method is proposed to mitigate the initial model dependence problem. It utilizes a nonlinear operator based on FCEO and U-Net, and employs self-supervised learning to train U-Net. The numerical examples demonstrate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Environmental Sciences
Chen Song, Yu Wang, Guodong Jin, Yu Wang, Qinghai Dong, Bingnan Wang, Liangjiang Zhou, Pingping Lu, Yirong Wu
Summary: A novel nonlinear frequency modulation (NLFM) waveform design method for SAR jamming is proposed in this paper, which has high sidelobe jamming capability and significantly improves the jamming performance.
Article
Environmental Sciences
Ying Han, Qiao Wang, Jianping Huang, Jing Yuan, Zhong Li, Yali Wang, Jingyi Jin, Xuhui Shen
Summary: Through computer vision and machine learning techniques, we extracted the frequencies of global constant-frequency electromagnetic disturbances (CFEDs) and analyzed their spatial signal characteristics. The research findings contribute to enhancing the quality of observational data from the China Seismo-Electromagnetic Satellite (CSES) and provide a theoretical basis for constructing global CFED spatial background fields and earthquake monitoring and early prediction systems.
Article
Environmental Sciences
Yan Zhao, Lixin Zhang, Xin Zhao, Jin Liu, Ming Gao
Summary: High-frequency electronic descaling devices use high-frequency electromagnetic fields to slow down scale growth by changing the morphology of scaling substances and the physicochemical properties of water. Simulation results show that square wave excitation generates greater magnetic field energy compared to sine wave excitation, and increasing voltage leads to a continuous rise in the peak value of magnetic field energy. Increasing frequency causes a slight decrease in the peak values of magnetic field energy and magnetic flux within a certain range, followed by a rapid decrease due to waveform relaxation. Time and frequency increases significantly increase the influence of relaxation time.
Article
Engineering, Electrical & Electronic
Avner Shultzman, Yonina C. Eldar
Summary: This study proposes a nonlinear waveform inversion (NWI) approach for quantitative ultrasound reconstruction, which takes into account the nonlinear acoustic effects in medical ultrasound and simultaneously reconstructs multiple media properties. The method represents the nonlinear acoustic model using a recurrent neural network and applies efficient optimization algorithms, achieving more efficient reconstructions compared to traditional methods.
IEEE TRANSACTIONS ON COMPUTATIONAL IMAGING
(2022)
Article
Engineering, Electrical & Electronic
Arijit Roy, Harshal B. Nemade, Ratnajit Bhattacharjee
Summary: This paper investigates the design process of discrete frequency-coding waveform using nonlinear chirp, achieving improved autocorrelation sidelobe and cross-correlation peak levels. Through parameterized waveform design and optimization based on genetic algorithm, the proposed waveforms show significant improvement in performance compared to existing designs. The DFCW-NLC waveforms are proven to be superior candidates for MIMO and multiuser radar applications.
AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
Tiantian Wei, Wei Wang, Yongwei Zhang, Robert Wang
Summary: A novel nonlinear frequency modulation (NLFM) waveform is proposed in this study, which promises enhanced performance and flexibility through optimized waveform design, achieving lower sidelobes while maintaining a certain main lobe width, thus improving the synthetic aperture radar (SAR) system.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Thermodynamics
Hao Wang, Enyuan Wang, Zhonghui Li
Summary: The prediction of gas emission is important for coal and gas outburst prevention. This study established a dynamic prediction model based on gas flow analysis and found that gas emission is positively correlated with gas pressure, driving speed, and permeability coefficient, while negatively correlated with coal mass compressive strength.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Xiaofei Liu, Jifa Qian, Enyuan Wang, Zhenguo Zhang
Summary: This study investigated an integrated vortex ventilation and dust removal system for addressing dust pollution in coal mining operations. Both numerical simulation and field experiments demonstrated the system's effective dust control and removal capabilities, outperforming traditional ventilation methods.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Menghan Wei, Dazhao Song, Xueqiu He, Majid Khan, Zhenlei Li, Liming Qiu, Quan Lou
Summary: This study explored the low-frequency electromagnetic field excited by cracks in rocks and designed an electromagnetic antenna capable of simultaneously measuring in three axes. Signals from the same crack differ in directions at the same position, demonstrating directionality. The research outcomes provide a practical basis for characterizing electromagnetic radiations associated with rock fractures.
Article
Engineering, Mechanical
Xuelong Li, Shaojie Chen, Enyuan Wang, Zhonghui Li
Summary: This paper establishes an elastic-plastic-brittle mutation rockburst model for coal rock with structural surface, and researches the energy accumulation and dissipation mechanism during dynamic deformation and rupture to obtain the rockburst energy condition. Additionally, a volume element-region-system model of rockburst is established to explain the evolution process. The analysis of microseismic and electromagnetic radiation characteristics of coal rock provides a deeper understanding of the rockburst mechanism for accurate monitoring and early warning.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Environmental Sciences
Zhibo Zhang, Enyuan Wang, Xianan Liu, Majid Khan, Miao He, Yinghua Zhang
Summary: The accuracy of source location in acoustic monitoring is crucial for monitoring the stability of complex rock mass environments. Traditional methods using equivalent velocity may result in relatively large errors in complex rock mass environments. A new source location method based on Dijkstra's algorithm (SLMD) is proposed, which shows significantly higher accuracy than traditional methods, as demonstrated in laboratory experiments.
ENVIRONMENTAL EARTH SCIENCES
(2021)
Article
Engineering, Geological
Shengquan He, Dazhao Song, Hani Mitri, Xueqiu He, Jianqiang Chen, Zhenlei Li, Yarong Xue, Tuo Chen
Summary: This paper presents an integrated early rockburst warning model for underground mines, utilizing fuzzy comprehensive evaluation method and maximum membership degree principle to improve prediction accuracy. The model was successfully demonstrated in a coal mine in China.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Geochemistry & Geophysics
Hongwei Mu, Dazhao Song, Xueqiu He, Zhenlei Li, Dongfang Su, Yarong Xue
Summary: This study addresses the issue of rockburst early warnings in multi-seam mining by proposing a regional local integrated rockburst monitoring and early warning method. The method combines predictions of dynamic and static loads to effectively achieve early warning of rockburst in coal mines.
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Shan Yin, Dazhao Song, Jie Li, Xueqiu He, Liming Qiu, Quan Lou, Menghan Wei, Yang Liu
Summary: The HHT method is used to analyze and process the EMR waveform of coal failure process, effectively extracting the refined features of EMR waveform signal and improving the identification degree of the precursor characteristics of coal body instability. HHT method has an improved adaptability and superiority in revealing the characteristics of coal deformation and failure.
Article
Construction & Building Technology
Shan Yin, Dazhao Song, Xueqiu He, Quan Lou, Liming Qiu, Zhenlei Li, Chen Peng, Jie Li, Yang Liu
Summary: This study investigates the relationship between stress drop and acoustic-electrical energy during rock failure processes, finding that with the increase in stress drop dissipated energy, the released acoustic-electric energy gradually increases with a good linear positive correlation. A new indicator for monitoring rock structure health based on stress drop energy is established, allowing for the assessment of rock structure's health status.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Geochemistry & Geophysics
Liming Qiu, Yi Zhu, Dazhao Song, Xueqiu He, Weixiang Wang, Yang Liu, Yuzhe Xiao, Menghan Wei, Shan Yin, Qiang Liu
Summary: Coal and rock dynamic disasters pose a serious threat to miner safety and industrial production. The refined nonlinear characteristics of electromagnetic radiation (EMR) and acoustic emission (AE) during coal splitting failure were studied using Hilbert-H and multifractal theory, revealing valuable information about coal fracture law. The research showed that EMR and AE during coal splitting failure are related to the process of coal crack propagation, with similar initiation time and frequency band. However, EMR has a longer signal duration and lower frequency compared to AE. The research provides an effective method for studying the nonlinear refinement characteristics of coal EMR and AE.
Article
Geosciences, Multidisciplinary
Xianfeng Liu, Xiangguo Kong, Baisheng Nie, Dazhao Song, Xueqiu He, Longkang Wang
Summary: This study investigated the quantitative relationship between gas adsorption and pore characteristics in bituminous coals, introducing fractal theory to assess surface roughness. Different surface morphological characteristics and typical pore types were found in the samples, with micro-pore structures being more complex than meso-pores and transition pores. The fractal dimensions D-1 and D-2 were calculated to evaluate gas adsorption in coal, with D-1 having a greater influence on adsorption capacity than D-2.
NATURAL RESOURCES RESEARCH
(2021)
Article
Energy & Fuels
Majid Khan, He Xueqiu, Asam Farid, Song Dazhao, Zhenlei Li, Tian Xianghui, Ni Mingqi
Summary: A novel approach has been introduced for mapping induced fractures and associated lineaments based on microseismic data, which can help in identification and prediction of risk zones in coal mines. The study identified thousands of fractures and interpreted regional lineaments based on the orientation of these fractures. The spatial distribution of microseismic energy helped in identifying geological discontinuities and potential future collapse or rockburst risk zones.
Article
Mining & Mineral Processing
Xianghui Tian, Xueqiu He, Dazhao Song, Zhenlei Li, Majid Khan, Huifang Liu, Liming Qiu
Summary: This study characterizes the micro-surface morphology, modulus, adhesion, and potential of granite, shale, and limestone using an atomic force microscope. The results show that the micro-surface characteristics of the rocks vary, and these characteristics have important effects on gas adsorption and fracture formation.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Analytical
Yujie Peng, Dazhao Song, Liming Qiu, Honglei Wang, Xueqiu He, Qiang Liu
Summary: This paper proposes a new dynamic combined prediction method for gas concentration based on multivariate monitoring data analysis. The method utilizes Spearman's rank correlation coefficient for dynamic optimization of prediction indicators and combines time series and spatial topology features with Bi-LSTMs. The results show that the proposed model is more accurate compared to other models, reduces missing alarms for abnormal gas emissions, and improves early warning accuracy, thus enhancing safety production efficiency in coal mines.
