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Rock fracture mechanism of buffer blasting with cushion layer at the borehole bottom

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 325-334页

作者： Xinguang Zhu Chenxi Ding Zhe Sui Hong Su Xu Guo School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock *** involves analyses of the evolution patterns of blasting stress,characteristics of crack distribution,and rock fracture features in the ***,blasting model experiments were carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock *** experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock ***,the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the continuum-discontinuum element method(CDEM)and the Landau explosion source model,with varying thicknesses of bottom cushion *** numerical simulation results indicate that with increasing cushion thickness,the absorption of energy generated by the explosion becomes more pronounced,resulting in fewer cracks in the bottom rock *** illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.

关键词： bottom cushion layer blasting crack propagation continuum-discontinuum element method dynamic stress intensity factor

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A Sequential Rotation Filtering Network for High Circular Polarization Purity Antenna Array

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IEEE Microwave and Wireless technology Letters 2025年第4期35卷 428-431页

作者： Wu, Sifan Li, Jianxing Yao, Jiahui Cao, Yuanxi Xu, Kai-Da Xi'an Jiaotong University Shaanxi Key Laboratory of Deep Space Exploration Intelligent Information Technology School of Information and Communications Engineering Xi'an710049 China University of Electronic Science and Technology of China Zhejiang Quzhou324000 China

This letter introduces a sequential rotation filtering network (SRFN), enabling a 16×16 antenna array to achieve high circular polarization (CP) purity and enhanced frequency selectivity. The proposed SRFN integrates filtering, power dividing, and phase shifting functions, providing phase states of 0°, 90°, 180°, and 270° at the four output ports with 7th-order filtering response. Moreover, four sets of 8×8 subarrays are arranged orthogonally and connected to the outputs of the SRFN. Finally, a 16×16 antenna array is monolithically fabricated using the 3-D printing technology. Measurement results demonstrate an operating bandwidth (return loss >10 dB) of 27.7-29.6 GHz, with the radiation gain ranging from 29.5 to 30.5 dBic. Due to the proposed SRFN, the in-band axial ratio (AR) remains lower than 0.5 dB, while the out-of-band realized gain suppression exceeds 30 dB/GHz. The proposed SRFN methodology serves as an integrated feeding network for antenna arrays requiring high CP purity and frequency selectivity. © 2023 IEEE.

关键词： Circular polarization

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Adaptive VDI Session Placement via User Logoff Prediction

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Machine Intelligence Research 2025年第1期22卷 189-200页

作者： Wenping Fan Puhui Meng Yu Tian Min-Ling Zhang Yao Zhang School of Computer Science and Engineering Southeast UniversityNanjing210096China VMware Information Technology(China)Limited Beijing100190China Key Laboratory of Computer Network and Information Integration(Southeast University) Ministry of EducationNanjing210096China

After the global pandemic,DaaS(desktop as a service)has become the first choice of many companies’remote working *** the desktops are usually deployed in the public cloud when using DaaS,customers are more cost-sensitive which boosts the requirement of proactive power *** researches in this area focus on virtual desktop infrastructure(VDI)session logon behavior modeling,but for the remote desktop service host(RDSH)-shared desktop pools,logoff optimization is also *** systems place sessions by round-robin or in a pre-defined order without considering their logoff ***,these approaches usually suffer from the situation that few left sessions prevent RDSH servers from being powered-off which introduces cost *** this paper,we propose session placement via adaptive user logoff prediction(SODA),an innovative compound model towards proactive RDSH session ***,an ensemble machine learning model that can predict session logoff time is combined with a statistical session placement bucket model to place RDSH sessions with similar logoff time in a more centralized manner on RDSH ***,the infrastructure cost-saving can be improved by reducing the resource waste introduced by those RDSH hosts with very few hanging sessions left for a long *** on real RDSH pool data demonstrate the effectiveness of the proposed proactive session placement approach against existing static placement techniques.

关键词： Virtual desktop infrastructure(VDI)resource management remote desktop service logoff prediction adaptive modeling session placement

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Semantic and Sentiment Dual-Enhanced Generative Model for Script Event Prediction 31

Semantic and Sentiment Dual-Enhanced Generative Model for Sc...

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31st International Conference on Computational Linguistics, COLING 2025

作者： Wu, Feiyang Huang, Peixin Hu, Yanli Tan, Zhen Zhao, Xiang Laboratory for Big Data and Decision National University of Defense Technology China National Key Laboratory of Information Systems Engineering National University of Defense Technology China

ISBN: (纸本)9798891761964

Script Event Prediction (SEP) aims to forecast the next event in a sequence from a list of candidates. Traditional methods often use pre-trained language models to model event associations but struggle with semantic ambiguity and embedding bias. Semantic ambiguity arises from the multiple meanings of identical words and insufficient consideration of event arguments, while embedding bias results from assigning similar word embeddings to event pairs with similar lexical features, despite their different meanings. To address above issues, we propose a the Semantic and Sentiment Dual-enhanced Generative Model (SSD-GM). SSD-GM leverages two types of script event information to enhance the generative model. Specifically, it employs a GNN-based semantic structure aggregator to integrate the event-centric structure information, thereby mitigating the impact of semantic ambiguity. Furthermore, we find that local sentiment variability effectively reduces biases in event embeddings, while maintaining global sentiment consistency enhances predictive accuracy. As a result, SSD-GM adeptly captures both global and local sentiment of events through its sentiment information awareness mechanism. Extensive experiments on the Multi-Choice Narrative Cloze (MCNC) task demonstrate that our approach achieves better results than other state-of-the-art baselines. © 2025 Association for Computational Linguistics.

关键词： Embeddings

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Dynamic-prototype Contrastive Fine-tuning for Continual Few-shot Relation Extraction with Unseen Relation Detection 31

Dynamic-prototype Contrastive Fine-tuning for Continual Few-...

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31st International Conference on Computational Linguistics, COLING 2025

作者： Zhao, Simiao Tan, Zhen Pang, Ning Xiao, Weidong Zhao, Xiang National Key Laboratory of Information Systems Engineering National University of Defense Technology China Laboratory for Big Data and Decision National University of Defense Technology China

ISBN: (纸本)9798891761964

Continual Few-shot Relation Extraction (CFRE) aims to continually learn new relations from limited labeled data while preserving knowledge about previously learned relations. Facing the inherent issue of catastrophic forgetting, previous approaches predominantly rely on memory replay strategies. However, they often overlook task interference in continual learning and the varying memory requirements for different relations. To address these shortcomings, we propose a novel framework, DPC-FT, which features: 1) a lightweight relation encoder for each task to mitigate negative knowledge transfer across tasks;2) a dynamic prototype module to allocate less memory for easier relations and more memory for harder relations. Additionally, we introduce the None-Of-The-Above (NOTA) detection in CFRE and propose a threshold criterion to identify relations that have never been learned. Extensive experiments demonstrate the effectiveness and efficiency of our method in CFRE, making our approach more practical and comprehensive for real-world scenarios. © 2025 Association for Computational Linguistics.

关键词： Knowledge transfer

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Broadband single-polarization single-mode low confinement loss hollow core anti-resonant fiber with semi-elliptical nested tube

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Optical and Quantum Electronics 2025年第4期57卷 1-12页

作者： Lin, Wen Fei, Yihong Wang, Ning Jia, Hongzhi Engineering Research Center of Optical Instruments and Systems Ministry of Education Shanghai Key Laboratory of Modern Optical Systems School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai200093 China

In this paper, a hollow-core anti-resonant optical fibre containing a semi-elliptical nested tube is proposed, which has the characteristics of single-polarization, large bandwidth, single-mode and low confinement loss. By optimizing the structural design, the polarization extinction ratio (PER) of the fiber reaches 21,0183 at a wavelength of 1.55 μm, and the y-polarized fundamental mode loss is only 0.00086 dB/m. By changing the material and thickness of the semi-ellipsoidal nested tube, a large bandwidth of 280 nm was achieved in the wavelength range of 1.51-1.78 μm, with loss limited to less than 0.001 dB/m within the bandwidth range. The PER and higher-order mode extinction ratio of 4870, 1487, respectively. The loss remains below 0.01 dB/m when the bending radius exceeds 4.5 cm. Therefore, it is expected that this optical fiber can be used in optical devices such as fiber optic sensors, fiber optic lasers and fiber optic gyroscopes. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2025.

关键词： Single mode fibers

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Effect of Nanoscale Amorphization on Edge Dislocation Emission from a Bifurcated Crack Tip in Deformed Nanocrystalline Solids

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Mechanika 2025年第2期31卷 87-95页

作者： Song, Xiaoya Yu, Min Peng, Xianghua Hunan Province Key Laboratory of Engineering Rheology Central South University of Forestry and Technology Changsha410004 China College of Information Science and Engineering Hunan Women's University Changsha410004 China

The effect of nanoscale amorphization at the triple junction of grain boundaries on edge dislocation emission from a bifurcated crack tip in nanocrystalline materials has been suggested and theoretically described. A corresponding mechanical model has been established, and the exact analytical solution of the modified model was obtained using the complex potential method of elastic mechanics. The resultant force acting on the dislocation was calculated, and the analytical expression for the critical SIF corresponding to dislocation emission was obtained based on the dislocation emission criterion. The influence of the size, position, strength of nanoscale amorphization, and bifurcated crack shape on the critical SIF was discussed using numerical analysis. The study found that an increase in the angle between the main crack and the branched crack makes it more difficult for dislocations to emit from the bifurcated crack tip. The critical dislocation emission angle is independent of the angle between the main crack and the branched crack. The presence of nanoscale amorphization can reduce the high stress field near the bifurcated crack tip, making it difficult for dislocations to emit from the bifurcated crack tip, thereby reducing the toughness of the material caused by dislocation emission. © 2025 Kauno Technologijos Universitetas. All rights reserved.

关键词： Stress intensity factors

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Ultra-low power MoS2 optoelectronic synapse with wavelength sensitivity for color target recognition

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science China(information sciences) 2025年第4期68卷 187-196页

作者： Bo WEI Yabo CHEN Xiaotong HAN Yan KANG Bujia LIANG Cheng LI Xiaokuo YANG Liang FANG Yuanxi PENG Institute for Quantum Information & State Key Laboratory of High Performance Computing College of ComputerNational University of Defense Technology Fundamentals Department Air Force Engineering University College of Advanced Interdisciplinary Studies National University of Defense Technology Institute of Quantum Information Science and Technology College of ScienceNational University of Defense Technology College of Computer National University of Defense Technology

Optoelectronic synapses that integrate visual perception and pre-processing hold significant potential for neuromorphic vision systems（NVSs）. However, due to a lack of wavelength sensitivity, existing NVS mainly focuses on gray-scale image processing, making it challenging to recognize color images. Additionally, the high power consumption of optoelectronic synapses, compared to the 10 fJ energy consumption of biological synapses, limits their broader application. To address these challenges, an energy-efficient NVS capable of color target recognition in a noisy environment was developed,utilizing a MoS2optoelectronic synapse with wavelength sensitivity. Benefiting from the distinct photon capture capabilities of 450, 535, and 650 nm light, the optoelectronic synapse exhibits wavelength-dependent synaptic plasticity, including excitatory postsynaptic current（EPSC）, paired-pulse facilitation（PPF）, and long-term plasticity（LTP）. These properties can effectively mimic the visual memory and color discrimination functions of the human vision system. Results demonstrate that the NVS, based on MoS2optoelectronic synapses, can eliminate the color noise at the sensor level, increasing color image recognition accuracy from 50% to 90%. Importantly, the optoelectronic synapse operates at a low voltage spike of0.0005 V, consuming only 0.075 fJ per spike, surpassing the energy efficiency of both existing optoelectronic and biological synapses. This ultra-low power, color-sensitive device eliminates the need for color filters and offers great promise for future deployment in filter-free NVS.

关键词： optoelectronic synapse neuromorphic vision system color recognition 2D materials image pre-processing

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Lensless imaging through the Fourier-ADMM network with a cost-effective and easily fabricated phase mask

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Optics Letters 2025年第3期50卷 758-761页

作者： Xiong, Zhencong He, Wenjun Chen, Yijie Xu, Yifei Wang, Wenbo Fu, Yuegang School of Opto-Electronic Engineering Changchun University of Science and Technology Changchun130022 China Changchun University of Science and Technology Key Laboratory of Opto-Electric Measurement and Optical Information Transmission Technology Ministry of Education Changchun130012 China

In this Letter, we introduce the Fourier-ADMM (alternating direction method of multipliers) network, improving the Fourier-ADMM algorithm by integrating it with an additional backpropagation process. Simultaneously, we develop a cost-effective and easily fabricated phase mask for lensless imaging systems. While the simplified phase mask may challenge the image quality for its faults such as low contrast and a suboptimal signal-to-noise ratio, the capabilities of the Fourier-ADMM network effectively mitigate these issues. The fabrication of the phase mask requires inexpensive and readily available raw materials and tools, and the process itself does not necessitate any highly specialized or precision operations. Our experimental results demonstrate that, with the backing of this advanced decoding network, the camera equipped with the simplified phase mask is capable of delivering high-quality imaging and rapid response times. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Masks

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Fast Charging Protocols Design of Lithium-ion Battery: A Multiple Objective Bayesian Optimization Perspective

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IEEE Transactions on Transportation Electrification 2025年第3期11卷 8327-8338页

作者： Zhu, Rong Peng, Weiwen Yang, Fangfang Xie, Min City University of Hong Kong Department of Systems Engineering Hong Kong Sun Yat-sen University School of Intelligent Systems Engineering Shenzhen518107 China Guangdong Provincial Key Laboratory of Fire Science and Technology Guangzhou510006 China

Fast-charging lithium-ion batteries are crucial for accelerating the adoption of electric vehicles by reducing charging time and improving operational efficiency. However, fast charging presents a significant challenge due to the knee point in the battery degradation trajectory, beyond which capacity decreases rapidly. Optimizing fast-charging protocols that consider knee point capacity and cycle life is essential but requires extensive and costly cycling aging tests to obtain the necessary degradation labels. To address this challenge, a multi-objective Bayesian optimization framework is proposed for fast-charging protocol optimization, jointly considering knee point capacity and cycle life. To reduce experimental costs, two deep learning-based early prediction models are developed to predict knee point capacity and cycle life using data from the first 60 cycles. The framework employs a noisy expected hypervolume improvement acquisition function to handle prediction uncertainties during multi-objective optimization. Validation on publicly available battery datasets demonstrates that the proposed framework achieves effective optimization of fast-charging protocols while reducing experimental costs by approximately 90%. © 2015 IEEE.

关键词： Charging stations

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