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Friction 2024年第9期12卷 2033-2051页

作者： Qipeng HUANG Chaohua WU Xiaoliang SHI Kaipeng ZHANG school of mechanical and Electronic engineering Wuhan University of TechnologyWuhan 430070China school of Transportation and Logistics engineering Wuhan University of TechnologyWuhan 430063China

Wind power gears will be excessively worn due to lubrication failure during ***,the tribological properties of rubbing pairs are improved by filling solid lubricants into surface *** texture design,three types of topological textures(Circle(C),Hexagon(H),and Circle/Hexagon(CH))were obtained by cell topology optimization,and then three cases with 20%,30%,and 40%density were designed for each ***,SnAgCu and TiC were deposited in texture of AISI 4140 steel(AS)to obtain 9 kinds of self-lubricating *** them,AS with 30%CH density(AS-CH30)exhibits excellent mechanical and tribological *** with AS-C and AS-H,the maximum equivalent stress of AS-CH was decreased by 10.86%and 5.37%,*** coefficient and wear rate of AS-CH30 were 79.68%and 78%lower than those of *** excellent tribological performances of AS-CH30 can be attributed to the synergistic effect of topological surface and solid *** surface can not only reduce fluctuation of equivalent stress,but also promote the stored lubricants to be easily transferred at the contact interface to form a 200 nm lubricating film containing solid lubricants(mainly),oxides and wear debris.

关键词： topological texture nano-TiC self-lubricating solid lubrication

Quasi-two dimensional Ruddlesden−Popper halide perovskites for laser applications

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Frontiers of physics 2024年第2期19卷 53-71页

作者： Kun Chen Qianpeng Zhang Yin Liang Jiepeng Song Chun Li Shi Chen Fang Li Qing Zhang school of mechanical and electrical engineering Wuhan Institute of TechnologyWuhan 430205China school of Materials Science and engineering Peking UniversityBeijing 100871China institute of Applied Physics and Materials engineering Macao UniversityMacao 999078China

Quasi-two-dimensional(2D)Ruddlesden‒Popper(RP)halide perovskites,as a kind of emerged two-dimensional layered materials,have recently achieved great attentions in lasing materials field owing to their large exciton binding energy,high emission yield,large optical gain,and wide-range tuning of optical *** review will introduce research progresses of RP halide perovskites for lasing applications in aspects of materials,photophysics,and devices with emphasis on emission and lasing properties tailored by the molecular composition and *** materials,structures and fabrications are introduced in the first ***,the optical transitions and amplified spontaneous emission properties are discussed from the aspects of electronic structure,exciton,gain dynamics,and interface ***,the research progresses on lasing devices are summarized and several types of lasers including VCSEL,DFB lasers,microlasers,random lasers,plasmonic lasers,and polariton lasers are *** last,the challenges and perspectives would be provided.

关键词： two-dimensional materials metal halide perovskite Ruddlesden−Popper halide perovskites lasing emission

Surface plasmon-coupled radiative heat transfer between graphene-covered magnetic Weyl semimetals

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Science China Technological Sciences 2024年第11期67卷 3405-3412页

作者： SONG JinLin YAO XinJie JIN Lin CHEN Lei ZHAO HaiLong CHENG Qiang school of electrical and Information engineering Wuhan Institute of Technology State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and Technology

Weyl semimetals(WSMs) have recently attracted considerable research attention because of their remarkable optical and electrical properties. In this study, we investigate the near-field radiative heat transfer(NFRHT) between graphene-covered Weyl slabs, particularly focusing on the supported coupled surface plasmon polaritons(SPPs). Unlike bare Weyl slabs where the epsilon-near-zero(ENZ) effect contributes the most to the NFRHT, adding a monolayer graphene sheet yields coupled SPPs, i.e.,the coupling of graphene SPPs(GSPPs) and Weyl SPPs(WSPPs), which dominates the NFRHT. The graphene sheet greatly suppresses the ENZ effect by compressing the parallel wavevector, thereby enabling the heat transfer coefficient(HTC) to be significantly changed. Further, for the graphene-covered magnetic Weyl slab configuration, an increase in the number of Weyl nodes suppresses the SPP coupling and ENZ effect, thereby weakening the NFRHT with a regulation ratio of 4.4 whereas an increase in the Fermi level slightly influences the NFRHT. Several typical heterostructures are also proposed for comparison, and results show that a mono-cell structure has the largest total HTC. Our findings will facilitate the understanding of surface plasmon-coupled radiative heat transfer and enable opportunities in energy harvesting and thermal management at the nanoscale based on WSM-based systems.

关键词： near-field radiative heat transfer Weyl semimetal surface plasmon polariton epsilon-near-zero graphene

Saddlepoint Approximation Method in Reliability Analysis:A Review

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2329-2359页

作者： Debiao Meng Yipeng Guo Yihe Xu Shiyuan Yang Yongqiang Guo Lidong Pan Xinkai Guo school ofmechanical and electrical engineering University of Electronic Science and Technology of ChinaChengdu611731China institute of Electronic and Information engineering of UESTC in Guangdong Dongguan523808China Glasgow College University of Electronic Science and Technology of ChinaChengdu611731China Beijing Research institute of mechanical&electrical technology Ltd.Beijing100083China

The escalating need for reliability analysis(RA)and reliability-based design optimization(RBDO)within engineering challenges has prompted the advancement of saddlepoint approximationmethods(SAM)tailored for such *** article offers a detailed overview of the general SAM and summarizes the method characteristics ***,recent enhancements in the SAM theoretical framework are ***,the mean value first-order saddlepoint approximation(MVFOSA)bears resemblance to the conceptual framework of the mean value second-order saddlepoint approximation(MVSOSA);the latter serves as an auxiliary approach to the *** distinction is rooted in the varying expansion orders of the performance function as implemented through the Taylor *** the saddlepoint approximation and third-moment(SATM)and saddlepoint approximation and fourth-moment(SAFM)strategies model the cumulant generating function(CGF)by leveraging the initial random moments of the *** their optimal application domains diverge,each method consistently ensures superior relative precision,enhanced efficiency,and sustained *** method elucidated is exemplified through pertinent RA or RBDO *** juxtaposing them against alternative strategies,the efficacy of these methods becomes *** outcomes proffered are subsequently employed as a foundation for contemplating prospective theoretical and practical research endeavors concerning *** main purpose and value of this article is to review the SAM and reliability-related issues,which can provide some reference and inspiration for future research scholars in this field.

关键词： Reliability analysis reliability-based design optimization saddlepoint approximation

A novel multi-resolution network for the open-circuit faults diagnosis of automatic ramming drive system

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Defence technology（防务技术） 2024年第4期34卷 225-237页

作者： Liuxuan Wei Linfang Qian Manyi Wang Minghao Tong Yilin Jiang Ming Li school of mechanical engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina Northwest institute of mechanical and electrical engineering Xianyang 712099China

The open-circuit fault is one of the most common faults of the automatic ramming drive system(ARDS),and it can be categorized into the open-phase faults of Permanent Magnet Synchronous Motor(PMSM)and the open-circuit faults of Voltage Source Inverter(VSI). The stator current serves as a common indicator for detecting open-circuit faults. Due to the identical changes of the stator current between the open-phase faults in the PMSM and failures of double switches within the same leg of the VSI, this paper utilizes the zero-sequence voltage component as an additional diagnostic criterion to differentiate *** the variable conditions and substantial noise of the ARDS, a novel Multi-resolution Network(Mr Net) is proposed, which can extract multi-resolution perceptual information and enhance robustness to the noise. Meanwhile, a feature weighted layer is introduced to allocate higher weights to characteristics situated near the feature frequency. Both simulation and experiment results validate that the proposed fault diagnosis method can diagnose 25 types of open-circuit faults and achieve more than98.28% diagnostic accuracy. In addition, the experiment results also demonstrate that Mr Net has the capability of diagnosing the fault types accurately under the interference of noise signals(Laplace noise and Gaussian noise).

关键词： Fault diagnosis Deep learning Multi-scale convolution Open-circuit Convolutional neural network

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum Science 2024年第3期21卷 1969-1979页

作者： Yang Zhang Yong-An Li Xiang-Wei Kong Hao Liu Teng-Fei Sun College of mechanical and electrical engineering Beijing University of Chemical TechnologyBeijing 100027China school of Petroleum engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

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Rare Metals 2024年第9期43卷 4548-4565页

作者： Wen-Jie Liu Hui Li Qian-Xing Yin He-Jun Du school of Power and mechanical engineering Wuhan UniversityWuhan 430072China The institute of Technological Sciences Wuhan UniversityWuhan 430072China school of mechanical&Aerospace engineering Nanyang Technological UniversitySingapore 639798Singapore

Laser powder bed fusion(LPBF)is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional *** superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine *** the high demand for LPBF-manufactured superalloys,the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation,poor molten pool stability and sharp temperature ***,superalloys are characterized by severe pores,undesirable coarse columnar grains and poor mechanical *** this work,the effect of nano-TiN particles on defects,molten pool characteristics and microstructure and performance of the composites were *** 4.5 wt%TiN/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa,*** superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition,grain refinement and duplex nanophases ***,the stability of molten pool was enhanced,and spatter was effectively suppressed by adding nano-TiN particles,while grain refinement and columnar to equiaxed transitions were ***,the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g.,TiN and M_(23)C_(6)),resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Molten pool characteristics Microstructure mechanical properties

Analyses on an electronic voltage transformer's failure by its resonance with very fast transient overvoltage and suppression

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High Voltage 2024年第1期9卷 150-162页

作者： Ruoyu Han Houda Zhu Qing Chen Hongbin Li Yue Tong Linshan Han Yang Jiao school of electrical and Electronic engineering Huazhong University of Science and TechnologyWuhanChina China Electric Power Research institute WuhanChina school of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhanChina

As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary *** a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'*** address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an *** this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary *** addition,simulations and laboratory tests are conducted to prove this method's validity.

关键词： transient resonance mentioned

Printed Circuit Board (PCB) Surface Micro Defect Detection Model Based on Residual Network with Novel Attention Mechanism

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Computers, Materials & Continua 2024年第1期78卷 915-933页

作者： Xinyu Hu Defeng Kong Xiyang Liu Junwei Zhang Daode Zhang school of mechanical engineering Hubei University of TechnologyWuhan430068Chain

Printed Circuit Board(PCB)surface tiny defect detection is a difficult task in the integrated circuit industry,especially since the detection of tiny defects on PCB boards with large-size complex circuits has become one of the *** improve the performance of PCB surface tiny defects detection,a PCB tiny defects detection model based on an improved attention residual network(YOLOX-AttResNet)is ***,the unsupervised clustering performance of the K-means algorithm is exploited to optimize the channel weights for subsequent operations by feeding the feature mapping into the SENet(Squeeze and Excitation Network)attention network;then the improved K-means-SENet network is fused with the directly mapped edges of the traditional ResNet network to form an augmented residual network(AttResNet);and finally,the AttResNet module is substituted for the traditional ResNet structure in the backbone feature extraction network of mainstream excellent detection models,thus improving the ability to extract small features from the backbone of the target detection *** results of ablation experiments on a PCB surface defect dataset show that AttResNet is a reliable and efficient *** Torify the performance of AttResNet for detecting small defects in large-size complex circuit images,a series of comparison experiments are further *** results show that the AttResNet module combines well with the five best existing target detection frameworks(YOLOv3,YOLOX,Faster R-CNN,TDD-Net,Cascade R-CNN),and all the combined new models have improved detection accuracy compared to the original model,which suggests that the AttResNet module proposed in this paper can help the detection model to extract target *** them,the YOLOX-AttResNet model proposed in this paper performs the best,with the highest accuracy of 98.45% and the detection speed of 36 FPS(Frames Per Second),which meets the accuracy and real-time requirements for the detection of tiny defect

关键词： Neural networks deep learning ResNet small object feature extraction PCB surface defect detection

Application of epoxy resin in cultural relics protection

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Chinese Chemical Letters 2024年第4期35卷 31-42页

作者： Zhaoru Chen Xiaoxu Liu Haonan Chen Jialong Li Xiaofeng Wang Jianfeng Zhu Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials School of Material Science and EngineeringShaanxi University of Science and TechnologyXi'an 710021China College of mechanical&electrical engineering Shaanxi University of Science and TechnologyXi'an 710021China

Cultural relics have their unique artistic, cultural and historical value, and the protection of important cultural relics is conducive to the inheritance of historical culture. As a kind of cementing agent and binder commonly seen in cultural relics protection, epoxy resin is widely used in the bonding and consolidation of various materials in cultural relics, which has important practical application value. In this review, a systematic classification of commonly used epoxy resins, including their molecular structures, synthesis reactions and properties are provided, the problems and solutions of epoxy resin in cultural relics protection are summarized. The solutions are classified into three aspects: functional epoxy resin, blending modification, and other modification. Representative application examples of epoxy resin are listed in the field of cultural relics protection, and the development direction of epoxy resin in cultural relics protection in the future is proposed, which provides useful guidance for the modification of epoxy resin and its application in cultural relics protection in the future.

关键词： Epoxy resin Cultural relics Modified UV resistance