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Tensile Fracture Propagation in Deep Coalbed Methane Layers Under Brazilian Test: A Quantitative Analysis Using Digital Rock technology and Deep Learning-Based Image Segmentation

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Rock Mechanics and Rock Engineering 2025年 1-29页

作者： Golsanami, Naser Guo, Dingrui Fernando, Shanilka G. Kumral, Mustafa Jiang, Lishuai Raveendrasinghe, Thanuja Saberali, Behzad Saedi, Ghasem Yan, Weihcao Bakhshi, Elham Ahmad, Qazi Adnan Dolbnya, Olga V. Kozlov, Roman Behnia, Mahmoud Jayasuriya, Madusanka N. State Key Laboratory of Disaster Prevention and Ecology Protection in Open-pit Coal Mines Shandong University of Science and Technology Qingdao China College of Energy and Mining Engineering Shandong University of Science and Technology Qingdao China Department of Mining and Materials Engineering McGill University Montréal Canada College of Earth Science and Engineering Shandong University of Science and Technology Qingdao China Department of Physical Sciences Faculty of Applied Sciences South Eastern University of Sri Lanka Sammanthurei Sri Lanka School of Petroleum Engineering China University of Petroleum (East China) Qingdao China National Iranian South Oil Company Ahvaz Iran Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Lab of Submarine Geosciences and Prospecting Techniques MOE and College of Marine Geosciences Ocean University of China Qingdao China Deep-Sea Multidisciplinary Research Center National Laboratory for Marine Science and Technology Qingdao China Department of Engineering Systems Talca University Talca Chile Department of Mining Engineering Isfahan University of Technology Isfahan Iran Department of Mechanical Engineering Faculty of Engineering University of Sri Jayewardenepura Ratmalana Sri Lanka

Tensile fracture propagation is a critical aspect of both coalbed methane exploitation and underground coal mining. A significant gap in the existing knowledge is the quantitative understanding of tensile fractures’ initiation and propagation within the context of the existing pore fracture network. This research addresses this gap using such cutting-edge technologies as deep learning, computed tomography (CT) scanning, scanning electron microscope (SEM), and mechanical loading under Brazilian Test conditions. Coal samples from the Ordos Basin of China underwent step-by-step loading, and CT scanning was conducted before and after each loading step. Then, the tensile fractures’ evolution was investigated. A deep learning technique was employed for accurate image segmentation. The developed models were transformed into a user-friendly Windows-based App, providing a valuable resource for fellow researchers. The analyses revealed insights into the initiation, propagation, extension, and growth of tensile fractures. Two-dimensional (2D) and three-dimensional (3D) analyses considered fracture length, aperture, density, and volume, leading to the formulation of relevant rock mechanical and geomechanical models. This research contributes valuable insights into the intricate interplay between natural fractures and tensile fractures’ dynamics based on the pore space evolution pattern. The findings have significant implications for coalbed methane extraction and coal mining.

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A 23-34 GHz Wideband GaN Low-Noise Amplifier for 5G Millimeter-Wave Applications

A 23-34 GHz Wideband GaN Low-Noise Amplifier for 5G Millimet...

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IEEE International Workshop on Electromagnetics, Applications and Student Innovation (iWEM)

作者： Yubin Li Xueying Wu Jun Hu Xiuyin Zhang Yun Yin Hongtao Xu State Key Laboratory of ASIC and System Fudan University Shanghai China Pazhou Lab Guangzhou China School of Electronic and Information Engineering South China University of Technology South China University of Technology Guangzhou China

ISBN: (纸本)9781665418294

This paper presents a design of 23-34 GHz wideband low-noise amplifier (LNA) based on gallium-nitride (GaN) technology. The LNA circuit employs an input matching network with few components and particularly reduces the noise of the second stage at the high frequency, which makes the circuit achieve sub-1dB noise performance in the whole bandwidth, while completing noise and impedance matching. Because inductive peaking technique and stagger tuning technique are adopted, the small-signal gain of the LNA is from 22.1 dB to 25.2 dB over the whole bandwidth. With 30.9 dBm maximum output-referred third-order intercept point (OIP3) and 42 dBm maximum input power (P in,max ), the LNA also achieves high linearity and high reliability.

关键词： Low-noise amplifiers Technological innovation Impedance matching Simulation Linearity Reliability High frequency

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Self-powered solar-blind photodiodes based on EFG-grown(100)-dominant β-Ga_(2)O_(3) substrate

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Chinese Physics B 2021年第1期30卷 483-486页

作者： Xu-Long Chu Zeng Liu Yu-Song Zhi Yuan-Yuan Liu Shao-Hui Zhang Chao Wu Ang Gao Pei-Gang Li Dao-You Guo Zhen-Ping Wu Wei-Hua Tang Laboratory of Information Functional Materials and Devices School of Science&State Key Laboratory of Information Photonics and Optical CommunicationsBeijing University of Posts and TelecommunicationsBeijing 100876China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China The Engineering Research Center for Semiconductor Integrated Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China China Aerospace System Simulation Technology Co. Ltd.(Beijing)Beijing 100195China Division of Interdisciplinary and Comprehensive Research&Platform for Characterization and Test Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China Center for Optoelectronics Materials and Devices&Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhou 310018China School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210046China National and Local Joint Engineering Laboratory for RF Integration and Micro-Packing Technologies Nanjing University of Posts and TelecommunicationsNanjing 210046China

We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky *** device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 *** addition,the photodiode detector shows a dark current of 0.3 pA,a photo-responsivity(R) of 2.875 mA/W,a special detectivity(D*) of 10^(10) Jones,and an external quantum efficiency(EQE) of 1.4% at zero bias,illustrating a self-powered *** work may advance the development of the Ga_(2)O_(3)-based Schottky diode solar-blind photodetectors.

关键词： β-Ga_(2)O_(3)substrate Schottky photodiode solar-blind detection

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Temperature Field Simulation and Ampacity Optimization of 500kV HVDC Submarine Transmission Cable

Temperature Field Simulation and Ampacity Optimization of 50...

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Advanced Electrical Equipment and Reliable Operation (AEERO), International Conference on

作者： Umer Farooq Fan Yang Jamshed Ali Shaikh Muhammad Shoaib Bhutta Farooq Aslam Wu Tao Li Jinxian Inzamam Ul Haq State Key Laboratory of Power Transmission Equipment & System Security and New Technology School of Electrical Engineering Chongqing University Chongqing China School of Electronics and Information Engineering Wuxi University Wuxi China State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University Xian China

ISBN: (纸本)9781665402651

The HVDC submarine power cables have complex structure and needs extraordinary manufacture process requirements. The HVDC submarine cable in an offshore wind farm usually goes through multiple laying sections with different laying environment. And in some of the sections, the heat dissipation condition may be unfavorable. To improve the safety of the transmission line, it is obligatory to study the cable temperature field and ampacity of power cable under different laying conditions and find the bottleneck sections, together with the methods to improve the ampacity of these weak sections. A 500kV XLPE submarine power cable is taken as the study object, the finite element modeling (FEM) is used to study the electromagnetic thermal coupling model of the submarine cables laying in the soil without trench, in the tube with water flowing for the purpose of forced cooling at beach section is established respectively to study the temperature field and ampacities by using COMSOL Multiphysics software. The results indicate that, water circulating in the tube would affect the cable heat dissipation and significantly ampacity is increased. Moreover, it has been noted that when the water flow rate is 2.78 L/s in the tube, the ampacity of cable is optimum and by the implementation of this proposed model the ampacity can be increased up to 650A.

关键词： Underwater cables Temperature distribution Power cables HVDC transmission Soil Conductivity Thermal conductivity

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An Improved Chimp Optimization Algorithm for Short-term Hydrothermal Scheduling

IAENG International Journal of Computer Science

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IAENG International Journal of Computer Science 2022年第3期49卷

作者： Chen, Gonggui Wang, Shumin He, Yongsheng Shang, Wanfeng Long, Hongyu Key Laboratory of Industrial Internet of Things and Networked Control Ministry of Education Chongqing University of Posts and Telecommunications Chongqing400065 China Chongqing University of Posts and Telecommunications Chongqing400065 China State Grid Chongqing Electric Power Company Chongqing400015 China Guangdong Provincial Key Lab of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen Shenzhen518055 China Chongqing Key Laboratory of Complex Systems and Bionic Control Chongqing University of Posts and Telecommunications Chongqing400065 China

The short-term hydrothermal scheduling (STHS) is a complex non-linear, non-convex and high-dimensional mathematical optimization problem. Due to the fact that the original chimp optimization algorithm (ChOA) is likely to fall into local optimum and has the disadvantage of low population diversity, an improved chimp optimization algorithm (IChOA) is proposed to solve the STHS problem. Firstly, Logistic-Tent chaotic mapping is employed to initialize the population and increase the population diversity. Then a new nonlinear convergence factor is introduced to make the optimization search process more applicable to STHS problems. Next, particle swarm algorithm (PSO) and gravitational search algorithm (GSA) are combined to enhance the shortcoming and balance the global search ability and local exploration ability of ChOA. Moreover, Cauchy mutation and opposition-based learning strategy are supplemented as perturbation interference when the optimal position is not updated to improve the ability to leap out of the local optimum. Finally, a graded optimization strategy is adopted for the constraint handing of dynamic reservoir balance and thermal power balance. Three standard hydrothermal power systems are utilized to verify the practicability and validity of the proposed method. Results of simulations reveal that IChOA has significant competitive advantages in addressing the STHS problem. © 2022, IAENG International Journal of Computer Science. All Rights Reserved.

关键词： Particle swarm optimization (PSO)

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Study about anti-icing effect of weatherproof super-hydrophobic coating on wind turbine

Study about anti-icing effect of weatherproof super-hydropho...

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22nd International Symposium on High Voltage Engineering (ISH 2021)

作者： H. Yang Q. Hu X. Jiang L. Shu X. Yang State Key Laboratory of Power Transmission Equipment & System Safety and New Technology School of Electrical Engineering Chongqing University Chongqing China State Grid Chongqing ShiNan Power Supply Company Nanan Chongqing China

In the regions with low temperature and high humidity, ice on the blades affects the safety and efficient operation of wind turbines seriously. The large static contact angle and low rolling angle properties of super-hydrophobic coating can effectively delay the icing process on wind turbine blades. However, low temperature, high humidity and flow crash limit the large-scale application of super-hydrophobic coating on operating wind turbines. In this paper, one kind of weatherproof super-hydrophobic coating produced by self-assembly precipitation method is proposed, with wear-resistance, acid- and alkali-resistance properties tested. Results show that the coating has good wear-resistance, acid-resistance and alkali-resistance properties, and the coating has a certain retardation effect on glaze and mixed ice during the inception of icing.

关键词： abrasion blades coatings contact angle freezing ice self-assembly wear resistance wind turbines hydrophobicity

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Wheel's Slip Ratio and Sinkage Estimation for Planetary Rovers Moving on Deformable Terrain

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Journal of Physics: Conference Series 2022年第1期2203卷

作者： Huaiguang Yang Liang Ding Haibo Gao Zongquan Deng State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 Heilongjiang China

Planetary rover plays a significant role in the lunar and Mars exploration missions and wheel's move status such as sinkage and slip ratio are the critical Factor to estimate the moving ability of the Mars rover. A method is proposed to estimate wheel's sinkage and skid angle based on terramechanic model and estimate slip ratio based on rover's dynamic model using Extended Kalman Filter algorithm. The proposed method can avoid the errors caused by Visual Odometry and improves the estimation accuracy of rover state through the fusion with other sensors' data. The effectiveness of the estimation method for planetary rovers is verified by comparing with the results obtained from dynamic simulation of Mars rovers.

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Dynamic Charge Modulate Lithium Uniform Plating Functional Composite Anode for Dendrite-Free Lithium Metal Batteries

SSRN

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SSRN 2022年

作者： Li, Meicheng Zhang, Wendi Fan, Qianxiao Zhang, Dongmei Liu, Lehao Liu, Shen Fang, Zhengyuan Li, Wei Li, Xiaodan State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing102206 China Fujian Provincial Key Laboratory of Functional Materials and Applications School of Materials Science and Engineering Xiamen University of Technology Xiamen361024 China Benjamin M. Statler College of Engineering and Mineral Resources West Virginia University MorgantownWV26506 United States

Lithium metal is considered as the ‘sharp blade’ to break through the limitation on energy density of lithium batteries. However, uneven plating of lithium metal during charge/discharge process causes serious safety hazards. Here, a carbon-based 3D skeleton (CC@Co-NCNTs) with Co nanocrystals anchored N-containing carbon nanotubes (Co-NCNTs) was constructed to induce the uniform lithium plating towards dendrite-free lithium metal batteries. The Co-NCNTs in the skeleton exhibit enhanced lithophilicity, supplying abundant nucleation sites. Moreover, the ingenious hierarchical structure reconstructs the current density distribution, promoting the uniform lithium plating. Particularly, the electrons from the Co nanocrystals are transferred to the surface of Co-NCNTs, which offers a dynamic charge distribution on the surface of the skeleton along with the plating of lithium ions during the charge-discharge process, thus modulating uniform lithium plating on the Co-NCNTs skeleton. The above-mentioned mechanism is further verified by first-principle calculations and multi-physical field simulation. Thus, the CC@Co-NCNTs@Li symmetric cell presents a long-term cyclic stability (over 1300 h) at a high current density of 40 mA cm -2 . The CC@Co-NCNTs@Li/LFP cell still delivers a discharge capacity of 135 mAh g -1 at 1 C after 500 cycles. This work provides new insights to the study of functional skeletons for dendrite-free lithium batteries. © 2022, The Authors. All rights reserved.

关键词： Carbon nanotubes

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Study on Physicochemical and Electrical Properties of Different Oil-based Natural Ester Insulating Oils during Thermal Aging

Study on Physicochemical and Electrical Properties of Differ...

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Advanced Electrical Equipment and Reliable Operation (AEERO), International Conference on

作者： Mengzhao Zhu Zhaoliang Gu Wei Xu Feng Yi Zhixin Gao Chenyu Gao State Grid Shandong Electric Power Company Shandong Electric Power Research Insititute Jinan China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China

ISBN: (纸本)9781665402651

Natural ester, has the ability of protecting cellulose which could efficiently delay the aging of insulation pressboard, and is regard as the best alternative to mineral oil (MO). In this paper, an accelerated thermal aging test of oilpaper samples $120^{\circ}C$ was conducted, including mineral oil, FR3 oil, PFAE oil, cellulose insulation pressboard and thermally upgraded paper. The key parameters of insulating oils were analyzed, including liquid colour, power frequency breakdown voltage, thermal conductivity, specific heat capacity and infrared spectrum. Results show that PFAE has the highest power frequency breakdown voltage and slightest colour change during the aging process. The thermal conductivity and specific heat capacity of MO, PFAE and FR3 oil with different aging degrees all increased with the increase of temperature. Among the three insulating oils, PFAE has a relatively high specific heat capacity, which would be beneficial to reduce the transformer operating temperature. The infrared spectrum analysis shows that C-H vibration peaks appears in MO, but in PFAE and FR3 oil, the C=O stretching vibration peaks also exist which reflects the different structure of three insulating oils. This study has a certain reference value for the fault diagnosis and evaluation of natural ester transformer in the future.

关键词： Vibrations Oils Color Aging Oil insulation Conductivity Thermal conductivity

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Correction to: a novel method for optimizing regional-scale management zones based on a sustainable environmental index

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Precision Agriculture 2023年第1期25卷 283-284页

作者： Li, Yue Cammarano, Davide Yuan, Fei Khosla, Raj Mandal, Dipankar Fan, Mingsheng Ata-UI-Karim, Syed Tahir Liu, Xiaojun Tian, Yongchao Zhu, Yan Cao, Weixing Cao, Qiang National Engineering and Technology Center for Information Agriculture MOE Engineering Research Center for Smart Agriculture MARA Key Laboratory for Crop System Analysis and Decision Making Jiangsu Key Laboratory for Information Agriculture Collaborative Innovation Centre for Modern Crop Production Co-sponsored by Province and Ministry Nanjing Agricultural University Nanjing China Department of Agroecology iClimate CBIO Aarhus University Tjele Denmark Department of Geography Minnesota State University Mankato USA Department of Agronomy Kansas State University Manhattan USA College of Resources and Environmental Sciences National Academy of Agriculture Green Development China Agricultural University Beijing China Graduate School of Agricultural and Life Sciences The University of Tokyo Bunkyo Tokyo Japan

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