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基于改进VGG网络的人脸表情识别

计算机应用文摘 2024年第19期40卷 94-96页

作者：杨旭黄昂肖梦迪王兴宏朱琪阜阳幼儿师范高等专科学校安徽阜阳236000

在特征提取过程中,传统卷积神经网络常采用单一尺寸的卷积核。随着网络结构的加深,浅层特征无法直接传递给分类器,因此难以准确完整地表达出数据的特征信息。对此,文章提出了基于改进VGG网络的人脸表情识别算法,在VGG16网络中引用Incept... 详细信息

在特征提取过程中,传统卷积神经网络常采用单一尺寸的卷积核。随着网络结构的加深,浅层特征无法直接传递给分类器,因此难以准确完整地表达出数据的特征信息。对此,文章提出了基于改进VGG网络的人脸表情识别算法,在VGG16网络中引用Inception和跳跃连接来提高特征的提取和传递能力,从而提高表情识别效果。实验结果表明,改进后的VGG结构在Fer2013数据集上具有比原始VGG网络更高的识别率。

关键词： VGG16 Inception 跳跃连接批量归一化

Effect of Shrinkage Reducing Agent and Steel Fiber on the Fluidity and Cracking Performance of Ultra-High Performance Concrete

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Fluid Dynamics & Materials Processing 2024年第9期20卷 1941-1956页

作者： Yong Wan Li Li Jiaxin Zou Hucheng xiao mengdi Zhu Ying Su Jin Yang Wuhan Metro Bridge and Tunnel Management Co. Ltd.Wuhan430068China School of Civil Engineering Architecture and EnvironmentHubei University of TechnologyWuhan430068China

Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of *** this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were *** with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking ***,different SRA incorporation methods,dosage and different SF types and aspect ratios were *** incorporation of SRA and SF led to a decrease in the fluidity of *** internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,***,SRA and SF improved the UHPC shrinkage cracking ***-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,*** addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively.

关键词： Ultra-high performance concrete chemical shrinkage reducing agent steel fiber shrinkage cracking repair and reinforcement

Catecholaminergic neurons orchestrate fasting-induced immune harmony

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Biophysics Reports 2024年第1期10卷 57-59页

作者： mengdi Guo Weiyan Wang xiao Tu Meiling Jiang Cun-Jin Zhang Department of Neurology Sichuan Provincial People's Hospital University of Electronic Science and Technology of China Department of Science and Technology Sichuan Provincial People's Hospital University of Electronic Science and Technology of China

Dietary fasting is a well-established intervention for immunosuppressive therapy, but the underlying mechanism remains elusive. Host fitness to nutritional stress has been confirmed to initiate a cascade of adaptive responses mediated by the central nervous system, shedding new light on a neural link between fasting and immunity(de Cabo and Mattson 2019).

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Experimental Study on the Molten Salt at Micron Scale during the Melting Process

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Journal of Thermal Science 2024年第1期33卷 70-85页

作者： TIAN Ziqian LIAO Zhirong XU Chao FANG Yongzhe JIANG Kaijun YUAN mengdi Key Laboratory of Power Station Energy Transfer Conversion and System Ministry of Education of ChinaSchool of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

The investigation of the melting behaviors of the molten salt at micron scale during the melting process is critical for explaining the solid-liquid phase transition *** this paper,a novel experimental system and analysis method were proposed to study the melting process with three heating rates in the range of1-10℃/min of the solar salt at micron *** solid-liquid boundary morphology and phase transition kinetics of molten salt particles were focused ***,the correlations between liquid fraction,temperature and time under different heating rates were *** solid-liquid boundary morphology was depicted by the visualized experimental set-up,and the instantaneous liquid volume fraction during the non-isothermal phase transition was ***,the correlation between temperature and liquid volume fraction was proposed to reveal the evolution of the solid-liquid boundary with temperature at different heating ***,the non-isothermal phase transition kinetic equation was established by introducing a constant parameter(V_(a,b)),and more kinetic parameters such as 1g V_(a,b) and-lg V_(a,b)/b were *** results showed that the exponent b is not sensitive to the heating rate with a range of 3-5 for solar salt ***,the heating rate influences the value of V_(a,b) and presents a positive ***,the non-isothermal phase transition kinetic equations at different heating rates in the range of 1-10℃/min can be quickly predicted by the proposed improved experimental test *** study could fill the research insufficiency and provide significant guidance for future research on the solid-liquid transition mechanism of molten salts at micron scale.

关键词： molten salt non-isothermal phase transition solid-liquid boundary morphology liquid volume fraction micron scale melting process

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Capturing and visualizing the phase transition mediated thermal stress of thermal barrier coating materials via a cross-scale integrated computational approach

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Journal of Advanced Ceramics 2024年第4期13卷 413-428页

作者： mengdi Gan Tianlong Lu Wei Yu Jing Feng xiaoyu Chong Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The generation and evaluation of severely high thermal stress(σ)is known to be responsible for failure of thermal barrier coatings(TBCs)during thermal *** is crucial and challenging to capture fluctuations inσcaused by the phase transition,which has motivated us to develop a high-throughput multiscale evaluation method forσin TBCs that considers the phase transition of the top ceramic materials by coupling first-principles calculations with finite element *** method quantitatively evaluates and visualizesσof the real TBC structure under thermal cycling by multifield ***,the thermophysical properties calculated by the first-principles calculations consider the effects of temperature and phase transition,which not only reduces the cost of obtaining data but also has a more physical *** this work,rare earth tantalites(RETaO_(4))are introduced as ceramic layers,and the results demonstrate thatσundergoes a rapid escalation near the phase transition temperature(T_(t)),particularly in the TBCs_GdTaO_(4) system,where it rises from 224 to 435 *** discontinuity inσmay originate from the significant alterations in Young’s modulus(increase by 27%–78%)and thermal conductivity(increase by 53%–146%)near T_(t).The TBCs_NdTaO_(4) and TBCs_SmTaO_(4) systems exhibit noteworthy temperature drop gradients and minimalσfluctuations,which are beneficial for extending service lifetime of *** approach facilitates the prediction of failure mechanisms and provides theoretical guidance for the reverse design of TBC materials to obtain low thermal stress systems.

关键词： thermal conductivity first-principles calculations thermodynamics thermal stress thermophysical properties

Optimizing piezoelectric performance of complex perovskite through increasing diversity of B-site cations

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Journal of Materials Science & Technology 2024年第3期170卷 78-86页

作者： mengdi Cheng Dongyan Zhang Yangxi Yan Zhimin Li Pangpang Wang Ri-ichi Murakami School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China Nanomaterials Group Institute of SystemInformation Technologies and Nanotechnologies(ISIT)Fukuoka Industry-Academia Symphonicity(FiaS)4-1 KyudaishinmachiNishi-kuFukuoka 819-0388Japan School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Piezoelectric materials with unique properties are hugely appealing for high sensitivity sensors and ultrasonic ***,Pb(Ni_(1/3)Nb_(2/3))O_(3)-Pb(Yb_(1/2)Nb_(1/2))O_(3)-PbTiO_(3)piezoelectric system was designed and investigated in *** optimized piezoelectric response(d_(33)=826 pC/N,d_(33)∗=1017 pm/V)together with good temperature stability and negligible performance degradation up to 10^(6) cycles was achieved in 0.58PNN-0.10PYN-0.32PT *** analysis revealed the amplification of intrinsic and extrinsic contributions in MPB region due to more spontaneous polarization orientations and an increase in chemical disorder of system after the introduction of *** origin of high piezoelectric response was investigated through the combination of scanning electron microscopy and piezoresponse force *** diversity of B-site cations was shown to enhance local structural heterogeneity,weaken long-range ferroelectric ordered domains,and lower free energy barrier via the formation of nanodomain configuration that promoted polarization rotation,thereby improving piezoelectric properties of the ***,it is suggested that increasing the diversity of B-site cations is an effective strategy for achieving outstanding piezoelectric performance.

关键词： PNN-PYN-PT ceramics Piezoelectricity enhancement Relaxation behavior Domain structure

Review of Fiber-Optic Localized Surface Plasmon Resonance Sensors:Geometries,Fabrication Technologies,and Bio-Applications

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Photonic Sensors 2024年第2期14卷 31-56页

作者： mengdi LU Chen WANG Ruizhi FAN Ming LIN Jianye GUANG Wei PENG Affiliated Cancer Hospital Dalian University of TechnologyShenyang 110042China School of Physics Dalian University of TechnologyDalian 116024China

Localized surface plasmon resonance(LSPR)biosensors,which enable nanoscale confinement and manipulation of light,offer the enhanced sensitivity and electromagnetic energy *** integration of LSPR with the fiber-optic technology has led to the development of compact and versatile sensors for miniaturization and remote *** comprehensive review explores various sensor configurations,fiber types,and geometric shapes,highlighting their benefits in terms of sensitivity,integration,and performance *** techniques such as focused non-chemical bonding strategies and self-assembly of nanoparticles are discussed,providing control over nanostructure morphology and enhancing sensor ***-applications of fiber-optic LSPR(FOLSPR)sensors are detailed,specifically in biomolecular interactions and analysis of proteins,pathogens and cells,nucleic acids(DNA and RNA),and other small molecules(organic compounds and heavy metal ions).Surface modification and detection schemes are emphasized for their potential for label-free and real-time *** challenges and prospects of FOLSPR sensors are addressed,including the developments in sensitivity,fabrication techniques,and measurement *** with emerging technologies such as nanomaterials is highlighted as a promising direction for future ***,this review provides insights into the advancements and potential applications of FOLSPR sensors,paving the way for sensitive and versatile optical biosensing platforms in various fields.

关键词： Fiber-optic localized surface plasmon resonance biosensor nanoparticles geometric configuration fabrication technology

Research on simulation of gun muzzle flow field empowered by artificial intelligence

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Defence Technology（防务技术） 2024年第2期32卷 196-208页

作者： mengdi Zhou Linfang Qian Congyong Cao Guangsong Chen Jin Kong Ming-hao Tong School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Northwest Institute of Mechanical and Electrical Engineering Xianyang712099ShaanxiChina School of Automation Nanjing University of Science and TechnologyNanjing210094China

Artificial intelligence technology is introduced into the simulation of muzzle flow field to improve its simulation efficiency in this paper.A data-physical fusion driven framework is ***,the known flow field data is used to initialize the model parameters,so that the parameters to be trained are close to the optimal *** physical prior knowledge is introduced into the training process so that the prediction results not only meet the known flow field information but also meet the physical conservation *** two examples,it is proved that the model under the fusion driven framework can solve the strongly nonlinear flow field problems,and has stronger generalization and *** proposed model is used to solve a muzzle flow field,and the safety clearance behind the barrel side is *** is pointed out that the shape of the safety clearance under different launch speeds is roughly the same,and the pressure disturbance in the area within 9.2 m behind the muzzle section exceeds the safety threshold,which is a dangerous *** with the CFD results shows that the calculation efficiency of the proposed model is greatly improved under the condition of the same calculation *** proposed model can quickly and accurately simulate the muzzle flow field under various launch conditions.

关键词： Muzzle flow field Artificial intelligence Deep learning Data-physical fusion driven Shock wave

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Variations of sediment organic phosphorus and organic carbon during the outbreak and decline of algal blooms in Lake Taihu,China

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Journal of Environmental Sciences 2024年第5期139卷 34-45页

作者： Jiehua Wang Xiuling Bai Wenchao Li Pingping Zhang mengdi Zhang Haoran Wang Yingge Bai College of Geography and Environmental Science Henan UniversityKaifeng 475004China Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(Henan University) Ministry of EducationKaifeng 475004China National Demonstration Center for Environment and Planning Henan UniversityKaifeng 475004China Surrey International Institute Dongbei University of Finance and EconomicsDalian 116000China

In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field *** results showed synchronous temporal changes in the sediment OP and OC contents with the development of *** addition,there was a significant positive correlation between the sediment OP and OC(p<0.01),suggesting simultaneous deposition and consumption during the ABs *** sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs *** temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak,even though algae are an important source of organic matter in *** depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs *** obtained results revealed significant differences in the sediment OC and OP contents between the months(p<0.05).In addition,OP in the sediments was dominated by orthophosphate diester(phospholipids and DNA-P)and orthophosphate monoester during the ABs outbreak and decline,*** active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period,demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.

关键词： Algal blooms Organic phosphorus Organic carbon Sediment ^(31)P NMR Lake Taihu

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