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Analysis of the interaction between bolt-reinforced rock and surface support in tunnels based on convergence-confinement method

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1936-1951页

作者： Zhenyu Sun Dingli Zhang Qian Fang Yanjuan hou Nanqi Huangfu Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing100044China

To investigate the interaction of the bolt-reinforced rock and the surface support,an analytical model of the convergence-confinement type is proposed,considering the sequential installation of the fully grouted rockbolts and the surface *** rock mass is assumed to be elastic-brittle-plastic material,obeying the linear Mohr-Coulomb criterion or the non-linear Hoek-brown *** to the strain states of the tunnel wall at bolt and surface support installation and the relative magnitude between the bolt length and the plastic depth during the whole process,six cases are categorized upon solving the *** case is divided into three stages due to the different effects of the active rockbolts and the passive surface *** fictitious pressure is introduced to quantify the threedimensional(3D)effect of the tunnel face,and thus,the actual physical location along the tunnel axis of the analytical section can be *** using the bolt-rock strain compatibility and the rocksurface support displacement compatibility conditions,the solutions of longitudinal tunnel displacement and the reaction pressure of surface support along the tunnel axis are *** proposed analytical solutions are validated by a series of 3D numerical *** parametric studies are conducted to examine the effect of the typical parameters of rockbolts and surface support on the tunnel displacement and the reaction pressure of the surface support under different rock *** results show that the rockbolts are more effective in controlling the tunnel displacement than the surface support,which should be installed as soon as possible with a suitable *** tunnels excavated in weak rocks or with restricted displacement control requirements,the surface support should also be installed or closed timely with a certain *** proposed method provides a convenient alternative approach for the optimization of rockbolts and surface support

关键词： Analytical model Longitudinal tunnel displacement Fictitious pressure Active rockbolts Surface support reaction pressure Tunnel design

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broadband absorption performance of 3D-printed polyetheretherketone-based electromagnetic wave-absorbing composites

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Chinese Journal of Aeronautics 2024年第8期37卷 547-558页

作者： Lin bAI Nan CHANG Meiying ZHAO Chi hou Yi CAO Dichen LI School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Chengdu Aircraft Design and Research Institute Chengdu 610091China Xi’an Key Laboratory of Advanced Structure Design and Application of Aircraft Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory for Manufacturing System Engineering Xi’an Jiaotong UniversityXi’an 710054China

The rapid development of additive manufacturing technology has offered a new avenue for designing and fabricating high wave-absorbing meta *** this study,the mechanical properties and broadband absorption performance of Poly-Ether-Ether-Ketone(PEEK)–based electromagnetic wave–absorbing composite materials was *** high-performance polymer PEEK was used as the matrix,and the materials with electromagnetic wave loss,such as reduced graphene oxide,Carbonyl Iron(CI),and Flake CI(FCI),were used as *** on the theory of impedance matching,a wave-absorbing structure with a gradual impedance gradient was designed and *** test results showed that at the 2.0–18.0 GHz frequency band,the coverage rate of the effective absorption bandwidth was up to 72.0%,the average optimal reflectivity was–18.09 db,and the wide-angle absorption range was 0°–30°.The advantages of additive manufacturing technology in designing and fabricating wave-absorbing structures are presented,demonstrating that the technology is an effective method for creating broadband absorbing structures.

关键词： Absorption performance Additive manufacturing Electromagnetic absorption PEEK composite materials Gradual structure broadband absorption

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Geology and Geochemistry of K-feldspar Veins in Lamprophyre at the Zhenyuan Gold Deposit,Yunnan,Southwest China:Implications for Gold Mineralization

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 104-116页

作者： ZHANG Huichao CHAI Peng ZHANG Hongrui Zhou Limin hou Zengqian Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Key Laboratory of Marine Hazards Forecasting Ministry of Natural ResourcesHohai UniversityNanjing 210024China National Research Center for Geoanalysis Beijing 100037China

Lamprophyres typically appear in hydrothermal gold *** relationship between lamprophyres and gold deposits is investigated *** researchers suggest that the emplacement of lamprophyres triggers gold mineralization,whereas others hypothesize that the formation of lamprophyres increases the fertility of mantle sources and ore-forming fluids.K-feldspar veins,with ages between those of lamprophyres and gold deposits,appear in lamprophyres in ***,K-feldspar veins are ideal for investigating the relationship between lamprophyres and gold *** in K-feldspar veins has lower Mg#,Ni,and Cr contents and higher TiO2,Li,ba,Sr,Sc,Zr,Nb,and Cs contents than phlogopite in *** in-situ Sr isotopic values of apatites(0.7063–0.7066)in K-feldspar veins are within the range for apatites(0.7064–0.7078)from *** large-ion lithophile element concentrations and low Nb and Ta concentrations in phlogopite from lamprophyres,in addition to high(87Sr/86Sr)i values of apatite(0.7064–0.7078),indicate that the magma parental to these phlogopite and apatite crystals is derived from an enriched *** veins are genetically correlated with lamprophyres,whereas sulfide mineral assemblage and trace element compositions of pyrite in K-feldspar veins suggest that K-feldspar veins in lamprophyres are not directly related to gold mineralization of the Zhenyuan deposit.

关键词： lamprophyre K-feldspar vein apatite Sr isotope gold Zhenyuan deposit Yunnan

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Modeling and Performance Analysis of UAV-Aided Millimeter wave Cellular Networks with Stochastic Geometry

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China Communications 2024年第6期21卷 146-162页

作者： Li Junruo wang Yuanjie Cui Qimei hou Yanzhao Tao Xiaofeng National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and TelecommunicationsBeijing 100876China National Computer Network Emergency Response Technical Team/Coordination Center of China(CNCERT/CC) Beijing 100029China Department of broadband Communication Peng Cheng LaboratoryShenzhen 518055China

UAV-aided cellular networks,millimeter wave(mm-wave) communications and multi-antenna techniques are viewed as promising components of the solution for beyond-5G(b5G) and even 6G *** leveraging the power of stochastic geometry,this paper aims at providing an effective framework for modeling and analyzing a UAV-aided heterogeneous cellular network,where the terrestrial base stations(TbSs) and the UAV base stations(UbSs) coexist,and the UbSs are provided with mm-wave and multi-antenna *** modeling the TbSs as a PPP and the UbSs as a Matern hard-core point process of type Ⅱ(MPH-Ⅱ),approximated but accurate analytical results for the average rate of the typical user of both tiers are derived through an approximation method based on the mean interference-to-signal ratio(MISR) *** influence of some relevant parameters is discussed in detail,and some insights into the network deployment and optimization are *** results show that some trade-offs are worthy of being considered,such as the antenna array size,the altitude of the UAVs and the power control factor of the UbSs.

关键词： average rate downlink millimeter wave point process theory SIR stochastic geometry UAVaided cellular networks

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Insights into Formation and Li-Storage Mechanisms of Hierarchical Accordion-Shape Orthorhombic CuNb2O6 toward Lithium-Ion Capacitors as an Anode-Active Material

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Energy & Environmental Materials 2024年第2期7卷 291-302页

作者： Chao Cheng Yunsheng Yan Minyu Jia Yang Liu Linrui hou Changzhou Yuan School of Material Science and Engineering University of Jinan

The orthorhombic CuNb2O6（O-CNO） is established as a competitive anode for lithium-ion capacitors（LICs） owing to its attractive compositional/structural ***,the high-temperature synthesis（>900 ℃） and controversial charge-storage mechanism always limit its ***,we develop a low-temperature strategy to fabricate a nano-blocksconstructed hierarchical accordional O-CNO framework by employing multilayered Nb2CTxas the niobium *** intrinsic stress-induced formation/transformation mechanism of the monoclinic CuNb2O6to O-CNO is tentatively put ***,the integrated phase conversion and solid solution lithium-storage mechanism is reasonably unveiled with comprehensive in（ex） situ *** to its unique structural merits and lithium-storage process,the resulted O-CNO anode is endowed with a large capacity of 150.3 mAh g-1at 2.0 A g-1,along with longduration cycling ***,the constructed O-CNO-based LICs exhibit a high energy(138.9 wh kg-1) and power(4.0 kw kg-1) densities with a modest cycling stability（15.8% capacity degradation after 3000consecutive cycles）.More meaningfully,the in-depth insights into the formation and charge-storage process here can promote the extensive development of binary metal Nb-based oxides for advanced LICs.

关键词： high-rate anodes lithium-ion capacitors lithium-storage mechanisms orthorhombic CuNb2O6 phase transform

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Irregular initial solidification by mold thermal monitoring in the continuous casting of steels:A review

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1003-1015页

作者： Qiuping Li Guanghua wen Fuhang Chen Ping Tang Zibing hou Xinyun Mo College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Occasional irregular initial solidification phenomena,including stickers,deep oscillation marks,depressions,and surface cracks of strand shells in continuous casting molds,are important limitations for developing the high-efficiency continuous casting of *** application of mold thermal monitoring(MTM) systems,which use thermocouples to detect and respond to temperature variations in molds,has become an effective method to address irregular initial solidification *** systems are widely applied in numerous steel companies for sticker breakout ***,monitoring the surface defects of strands remains ***,indepth research is necessary to utilize the potential advantages and comprehensive monitoring of MTM *** paper summarizes what is included in the irregular initial solidification phenomena and systematically reviews the current state of research on these phenomena by the MTM ***,the influences of mold slag behavior on monitoring these phenomena are ***,the remaining problems of the formation mechanisms and investigations of irregular initial solidification phenomena are discussed,and future research directions are proposed.

关键词： irregular initial solidification mold thermal monitoring continuous casting mold slag thermocouple

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Porous high-entropy rare-earth phosphate(REPO_(4),RE=La,Sm,Eu,Ce,Pr and Gd)ceramics with excellent thermal insulation performance via pore structure tailoring

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1651-1658页

作者： Peixiong Zhang Enhui wang Jingjing Liu Tao Yang Hailong wang Xinmei hou Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China Liaoning Academy of Materials Shenyang 110000China Technical Support Center for Prevention and Control of Disastrous Accidents in Metal Smelting University of Science and Technology BeijingBeijing 100083China School of Materials Science Engineering Zhengzhou UniversityZhengzhou 450001China

Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high *** this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4)(HE(6RE_(1/6))PO_(4))ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents(0–60vol%)on this ceramic properties was systematically *** results show that the porous HE(6RE_(1/6))PO_(4)ceramics with 60vol%starch exhibit the lowest thermal conductivity of 0.061 w·m^(-1)·K^(-1)at room temperature and good pore structure stability with a linear shrinkage of approximately1.67%.Moreover,the effect of large regular spherical pores(>10μm)on its thermal insulation performance was discussed,and an optimal thermal conductivity prediction model was *** superior properties of the prepared porous HE(6RE_(1/6))PO_(4)ceramics allow them to be promising insulation materials in the future.

关键词： porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4) ceramics high-entropy strategy pore-forming agent method thermal insulation material thermal conductivity

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Advanced transparent composite membranes for efficient ultraviolet protection and thermal regulation

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SCIENCE bULLETIN 2024年第18期69卷 2799-2801页

作者： hou, Yangzhe Su, Xiao Ma, Jun Univ South Australia UniSA STEM Mawson Lakes SA 5095 Australia Univ South Australia Future Ind Inst Mawson Lakes SA 5095 Australia

Throughout human history,our fundamental reliance on the sun has been evident in various activities,including farming,herding,fishing and *** designs have been profoundly influenced by the necessity to maximize sunlight intake,which is exemplified by the traditional Chinese architectural principle of“facing south with the back to the north”.This orientation promotes solar gain during cold months,enhancing the thermal efficiency of ***,the introduction of glass in the building construction has marked a significant advancement,which has enabled the effective utilization of natural light while providing protection from certain weather conditions such as wind and *** science and technology progress,solar energy is increasingly recognised as a plentiful and environmentally friendly source of energy,both renewable and devoid of pollution[1].

关键词： AbSORPTION FILMS

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Research on Improved MobileViT Image Tamper Localization Model

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Computers, Materials & Continua 2024年第8期80卷 3173-3192页

作者： Jingtao Sun Fengling Zhang Huanqi Liu wenyan hou School of Computer Science and Technology Xi’an University of Posts and TelecommunicationsXi’an710121China Shaanxi Key Laboratory of Network Data Analysis and Intelligent Processing Xi’an University of Posts and TelecommunicationsXi’an710121China

As image manipulation technology advances rapidly,the malicious use of image tampering has alarmingly escalated,posing a significant threat to social *** the realm of image tampering localization,accurately localizing limited samples,multiple types,and various sizes of regions remains a multitude of *** issues impede the model’s universality and generalization capability and detrimentally affect its *** tackle these issues,we propose FL-MobileViT-an improved MobileViT model devised for image tampering *** proposed model utilizes a dual-stream architecture that independently processes the RGb and noise domain,and captures richer traces of tampering through dual-stream ***,the model incorporating the Focused Linear Attention mechanism within the lightweight network(MobileViT).This substitution significantly diminishes computational complexity and resolves homogeneity problems associated with traditional Transformer attention mechanisms,enhancing feature extraction diversity and improving the model’s localization *** comprehensively fuse the generated results from both feature extractors,we introduce the ASPP architecture for multi-scale feature *** facilitates a more precise localization of tampered regions of various ***,to bolster the model’s generalization ability,we adopt a contrastive learning method and devise a joint optimization training strategy that leverages fused features and captures the disparities in feature distribution in tampered *** strategy enables the learning of contrastive loss at various stages of the feature extractor and employs it as an additional constraint condition in conjunction with cross-entropy *** a result,overfitting issues are effectively alleviated,and the differentiation between tampered and untampered regions is *** evaluations on five benchmark datasets(IMD-20,CASIA,NIST-16,Columbia and Coverage)validat

关键词： Image tampering localization focused linear attention mechanism MobileViT contrastive loss

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An Approximation Algorithm for the Parallel-Machine Customer Order Scheduling with Delivery Time and Submodular Rejection Penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 495-504页

作者： Hong-Ye Zheng Suo-Gang Gao wen Liu bo hou School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024HebeiChina

In this paper,we consider the parallel-machine customer order scheduling with delivery time and submodular rejection *** this problem,we are given m dedicated machines in parallel and n customer *** order has a delivery time and consists of m product types and each product type should be manufactured on a dedicated *** order is either rejected,in which case a rejection penalty has to be paid,or accepted and manufactured on the m dedicated *** objective is to find a solution to minimize the sum of the maximum delivery completion time of the accepted orders and the penalty of the rejected orders which is determined by a submodular *** design an LP rounding algorithm with approximation ratio of n+1 for this problem.

关键词： Order scheduling Delivery time Submodular rejection penalty Approximation algorithm

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