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Bubble dynamics properties of B-particles in a quasi-2D gas-solid fluidized bed:Computational particle fluid dynamics numerical simulation and post-processed by digital image analysis technique

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Particuology 2024年第3期86卷 223-238页

作者： Zemin yuan zhong Huang Guotao Qin Guanjia Zhao Suxia ma Hairui Yang Guangxi Yue Key Laboratory of Clean and Efficient Combustion and Utilization in the Circulating Fluidized Bed Taiyuan University ofTechnologyTaiyuan030024China Department of Energy and Power Engineering Tsinghua UniversityBeijing100084.China

Bubble dynamics properties play a crucial and significant role in the design and optimization of gas-solid fluidized *** this study,the bubble dynamics properties of four B-particles were investigated in a quasi-two-dimensional(quasi-2D)fluidized bed,including bubble equivalent diameter,bubble size distribution,average bubble density,bubble aspect ratio,bubble hold-up,bed expansion ratio,bubble radial position,and bubble *** studies were performed by computational particle fluid dynamics(CPFD)numerical simulation and post-processed with digital image analysis(DIA)technique,at superficial gas velocities ranging from 2u_(mf) to 7u_(mf).The simulated results shown that the CPFD simulation combining with DIA technique post-processing could be used as a reliable method for simulating bubble dynamics properties in quasi-2D gas-solid fluidized ***,it seemed not desirable for the simulation of bubble motion near the air distributor at higher superficial gas velocity from the simulated average bubble density *** superficial gas velocity significantly affected the bubble equivalent diameter and evolution,while it had little influence on bubble size distribution and bubble aspect ratio distribution for the same *** time-averaged bubble hold-up and bed expansion ratio increased with the increase of superficial gas *** core-annular flow structures could be found in the fluidized bed for all *** average bubble rising velocity increased with the increasing bubble equivalent *** bubble lateral movement,the smaller bubbles might be more susceptible,and superficial gas velocity had a little influence on the absolute lateral velocity of *** simulated results presented a valuable and novel approach for studying bubble dynamics *** comprehensive understanding of bubble dynamics behaviors in quasi-2D gas-solid fluidized beds would provide support in the design,operation,and optimization of gas-solid

关键词： Bubble dynamics properties CPFD simulation Quasi-2D gas-solid fluidized bed Digital image analysis

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Two-Dimensional Cavity Resonant Modes of Si Based Bragg Reflection Ridge Waveguide

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Chinese Physics Letters 2011年第6期28卷 225-228页

作者： CHEN San Lu Hong-Yan CHEN Kun-Ji XU Jun ma zhong-yuan LI Wei HUANG Xin-Fan School of Physics and Electronic Information Huaibei Normal UniversityHuaibei 235000 State Laboratory of Solid State Microstructures and Department of Physics Nanjing UniversityNanjing 210093

Si-based ridge-waveguides with Bragg reflectors are fabricated based on our *** resonant peaks could be obviously identified from the photoluminescence spectra,and field patterns of these resonant peaks,simulated by the finite difference time domain(FDTD)method,confirm that these peaks originate from cavity *** resonant wavelengths and spatial angular distribution are given by the resonant models,which agree well with the experimental ***,a simple method is proposed to testify the experimental and theoretical *** devices based on Bragg reflectors may have potential applications in light-emitting diodes,lasers and integrated photonic circuits.

关键词： Waveguide resonant diodes

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实验室检测环境条件开展监测情况分析

实验室检测

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实验室检测 2024年第6期2卷 149-152页

作者：丁小磊陆展杰马忠原杨神书范亚明江苏省疾病预防控制中心江苏仪路无忧科技发展有限公司

目的了解检验检测机构检测环境条件监测情况，分析存在问题并提供相应对策。方法通过自行设计问卷，调查实验室所在领域、类型、现有能力、信息化现状与监测现状等信息。通过第三方服务平台问卷星开展问卷调查，回收问卷183份，并通... 详细信息

目的了解检验检测机构检测环境条件监测情况，分析存在问题并提供相应对策。方法通过自行设计问卷，调查实验室所在领域、类型、现有能力、信息化现状与监测现状等信息。通过第三方服务平台问卷星开展问卷调查，回收问卷183份，并通过问卷星SPSSAU进行数据分析。结果调查了183家检验检测机构，实验室涉及的环境条件主要集中在温度、湿度、微生物污染、酸碱度和毒害腐蚀、有毒有害气体等，96.17%的实验室涉及温湿度，83.06%的实验室已经开展环境条件监测，监测的主要环境条件为温湿度，占86.34%，对电流、电压、光照、压力、噪声、振动、有害有毒气体等监测不足25%。仅有18.03%的检验检测机构已开展信息化监测，其他机构仍然通过传统的手工记录的方式开展监测登记。9.84%的检验机构建立了检验检测环境条件数据模型和趋势预警。结论本次调研数据分析发现国内包括政府实验室、企业实验室、第三方检验检测机构在内的实验室平台，其平台能力构成复杂、要求监测的环境条件种类繁多。但目前在监测技术融合、动态监测以及监测覆盖面方面还存在一定的不足，建议应通过建立环境条件监测信息化平台，利用数据模型建立起危险趋势预警机制、实现环境条件监测优化机制与干预管理。

关键词：监测现状数据模型实验室检测信息化

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Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

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Research 2024年第1期2023卷 651-662页

作者： Jian Yu zhong-Lin Wang Tianwei ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

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The Effect of Multiple Interface States and nc-Si Dots in a Nc-Si Floating Gate MOS Structure Measured by their G–V Characteristics

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Chinese Physics Letters 2013年第7期30卷 198-201页

作者： SHI Yong ma zhong-yuan CHEN Kun-Ji JIANG Xiao-Fan LI Wei HUANG Xin-Fan XU Ling XU Jun FENG Duan National Laboratory of Solid State Microstructures School of Electronic Science and EngineeringNanjing UniversityNanjing 210093

An nc-Si floating gate MOS structure is fabricated by thermal annealing of SiN_(x)/a-Si/SiO_(2).There are nc-Si dots isolated by a-Si due to partial ***-voltage(G–V)measurements are performed to investigate the effect of multiple interface states including Si-sub/SiO_(2),a-Si related(as-deposited sample)and nc-Si(annealed sample)in a charge trapping/releasing *** conductance peaks located in the depletion and weak inversion regions are found in our *** the as-deposited sample,the Si-sub/SiO_(2) related G–V peak with weak intensity shifts to the negative as test frequency *** a-Si related G–V peak with strong intensity shifts slightly with the increasing *** the annealed sample,little change appears in the intensity and shift of Si-sub/SiO_(2) related G–V *** position of a-Si/nc-Si related peak is independent of frequency,and its intensity is weaker compared to that of the as-deposited *** is also found that as the size of nc-Si becomes larger,the a-Si/nc-Si related peak shifts to the depletion region due to the size effect of nc-Si.

关键词： crystallization. process. annealed

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GNAS mutations suppress cell invasion by activating MEG3 in growth hormone–secreting pituitary adenoma

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Oncology Research 2024年第6期32卷 1079-1091页

作者： CHAO TANG CHUNYU zhong JUNHAO ZHU FENG yuan JIN YANG YONG XU CHIyuan ma Department of Neurosurgery Affiliated Jinling HospitalMedical School of Nanjing UniversityNanjing210002China Department of Neurosurgery Children’s Hospital of Nanjing Medical UniversityNanjing210019China Affiliated Eye Hospital Nanjing Medical UniversityNanjing210029China Department of Neurosurgery Jinling HospitalSouthern Medical UniversityNanjing210002China Department of Neurosurgery Jinling HospitalNanjing Medical UniversityNanjing210002China

Approximately 30%–40%of growth hormone–secreting pituitary adenomas(GHPAs)harbor somatic activating mutations in GNAS(αsubunit of stimulatory G protein).Mutations in GNAS are associated with clinical features of smaller and less invasive ***,the role of GNAS mutations in the invasiveness of GHPAs is *** mutations were detected in GHPAs using a standard polymerase chain reaction(PCR)sequencing *** expression of mutation-associated maternally expressed gene 3(MEG3)was evaluated with ***3 was manipulated in GH3 cells using a lentiviral expression *** invasion ability was measured using a Transwell assay,and epithelial–mesenchymal transition(EMT)-associated proteins were quantified by immunofluorescence and western ***,a tumor cell xenograft mouse model was used to verify the effect of MEG3 on tumor growth and *** invasiveness of GHPAs was significantly decreased in mice with mutated GNAS compared with that in mice with wild-type ***,the invasiveness of mutant GNASexpressing GH3 cells ***3 is uniquely expressed at high levels in GHPAs harboring mutated ***,MEG3 upregulation inhibited tumor cell invasion,and conversely,MEG3 downregulation increased tumor cell ***,GNAS mutations inhibit EMT in ***3 in mutated GNAS cells prevented cell invasion through the inactivation of the Wnt/β-catenin signaling pathway,which was further validated in *** data suggest that GNAS mutations may suppress cell invasion in GHPAs by regulating EMT through the activation of the MEG3/Wnt/β-catenin signaling pathway.

关键词： GHPAs GNAS mutation MEG3 β-catenin EMT

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A Lightweight Network with Dual Encoder and Cross Feature Fusion for Cement Pavement Crack Detection

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 255-273页

作者： zhong Qu Guoqing Mu Bin yuan School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing400065China School of Software Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this ***,as the performance of crack detection in cement pavement improves,the depth and width of the network structure are significantly increased,which necessitates more computing power and storage *** limitation hampers the practical implementation of crack detection models on various platforms,particularly portable devices like small mobile *** solve these problems,we propose a dual-encoder-based network architecture that focuses on extracting more comprehensive fracture feature information and combines cross-fusion modules and coordinated attention mechanisms formore efficient feature ***,we use small channel convolution to construct shallow feature extractionmodule(SFEM)to extract low-level feature information of cracks in cement pavement images,in order to obtainmore information about cracks in the shallowfeatures of *** addition,we construct large kernel atrous convolution(LKAC)to enhance crack information,which incorporates coordination attention mechanism for non-crack information filtering,and large kernel atrous convolution with different cores,using different receptive fields to extract more detailed edge and context ***,the three-stage feature map outputs from the shallow feature extraction module is cross-fused with the two-stage feature map outputs from the large kernel atrous convolution module,and the shallow feature and detailed edge feature are fully fused to obtain the final crack prediction *** evaluate our method on three public crack datasets:DeepCrack,CFD,and *** results on theDeepCrack dataset demonstrate the effectiveness of our proposed method compared to state-of-the-art crack detection methods,which achieves Precision(P)87.2%,Recall(R)87.7%,and F-score(F1)87.4%.Thanks to our lightweight cr

关键词： Shallow feature extraction module large kernel atrous convolution dual encoder lightweight network crack detection

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maUN:Memory-Augmented Deep Unfolding Network for Hyperspectral Image Reconstruction

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1139-1150页

作者： Qian Hu Jiayi ma yuan Gao Junjun Jiang Yixuan yuan Electronic Information School Wuhan UniversityWuhan 430072China School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China Department of Electronic Engineering Chinese University of Hong KongHong Kong 999077China

Spectral compressive imaging has emerged as a powerful technique to collect the 3D spectral information as 2D *** algorithm for restoring the original 3D hyperspectral images(HSIs)from compressive measurements is pivotal in the imaging *** approaches painstakingly designed networks to directly map compressive measurements to HSIs,resulting in the lack of interpretability without exploiting the imaging *** some recent works have introduced the deep unfolding framework for explainable reconstruction,the performance of these methods is still limited by the weak information transmission between iterative *** this paper,we propose a Memory-Augmented deep Unfolding Network,termed maUN,for explainable and accurate HSI ***,maUN implements a novel CNN scheme to facilitate a better extrapolation step of the fast iterative shrinkage-thresholding algorithm,introducing an extra momentum incorporation step for each iteration to alleviate the information ***,to exploit the high correlation of intermediate images from neighboring iterations,we customize a cross-stage transformer(CSFormer)as the deep denoiser to simultaneously capture self-similarity from both in-stage and cross-stage features,which is the first attempt to model the long-distance dependencies between iteration *** experiments demonstrate that the proposed maUN is superior to other state-of-the-art methods both visually and *** code is publicly available at https://***/HuQ1an/maUN.

关键词： Deep folding iteration

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Gradient microstructure and superior strength-ductility synergy of AZ61 magnesium alloy bars processed by radial forging with different deformation temperatures

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Journal of materials Science & Technology 2024年第3期170卷 65-77页

作者： Jingfeng Zou Lifeng ma Yanchun Zhu Ling Qin yuan yuan School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Heavy machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Engineering University of HullCottingham RdHull HU67RXUK National Engineering Research Center for magnesium Alloys Chongqing UniversityChongqing 400044China

Gradient microstructure modification is a cost-efficient strategy for high strength without compromising ductility,which is urgently needed in the fundamental science of engineering *** this study,heterogeneous structures of AZ61 alloy bars with anisotropic gradients(with different grain size distributions from the surface to the center)were observed to exhibit strong strength-ductility synergies under different deformation tem *** results reveal that the grain refinement process under mediumlow temperature deformation conditions(≤350℃)consists of four transition stages along the radial direction,i.e.,twin activations and deformation band formations,dislocation cells and pile-ups,ultrafine sub-grains,and randomly orientated quasi-micron *** deformation temperatures have a great influence on twin activations and deformation band formations,and the high temperature can easily provoke the initiation of non-basal *** deformation bands were determined as a primary nucleation site due to their highly unstable dislocation hindrance *** in combination with the Radial forging(RF)deformation process,the differences of dynamic precipitates can be attributed to microstructural difference and solubility limit of Al at different tem *** summarizing the tensile test results,the sample forged at 350℃exhibited the best strength-ductility synergy,exhibiting the highest elongation(EL)of 23.2%with a 251 MPa yield strength(YS)and 394 MPa ultimate tensile strength(UTS)in center region,and combined with the highest strength value of 256 MPa YS and 420 MPa UTS in the center region,while the EL was slightly degraded to 19.8%.

关键词： Gradient microstructure Radial forging Strength-ductility synergy magnesium alloy Strengthening mechanism

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Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu ma yuan LIU Ke HAN Yu TIAN Liran ma State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

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