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Integrating theory with the nanoreactor concept to synthesize hollow carbon sphere-encapsulated PtNi alloys for enhanced H_(2) generation

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Carbon Energy 2024年第7期6卷 150-162页

作者： Yufeng Wu Minwei song Ziyi Zhao Guang-Hui wang Changlong wang Didier Astruc Institute of Circular Economy Faculty of Materials and ManufacturingBeijing University of TechnologyBeijingChina Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdaoChina ISM UMR CNRS N°5255Universitéde BordeauxTalence CedexFrance

The rational design of efficient bimetallic nanoparticle(NP)catalysts is challenging due to the lack of theoretical understanding of active components and insights into the mechanisms of a specific ***,we report the rational design of nanoreactors comprising hollow carbon sphere-confined PtNi bimetallic NPs(PtNi@HCS)as highly efficient catalysts for hydrogen generation via ammonia borane hydrolysis in *** both density functional theory calculations and molecular dynamics simulations,the effects of an active PtNi combination and the critical synergistic role of a hollow carbon shell on the molecule diffusion adsorption behaviors are *** isotope effects and theoretical calculations allow the clarification of the mechanism,with oxidative addition of an O-H bond of water to the catalyst surface being the rate-determining *** remarkable catalytic activity of the PtNi@HCS nanoreactor was also utilized for successful tandem catalytic hydrogenation reactions,using in situ-generated H_(2) from ammonia borane with high *** concerted design,theoretical calculations,and experimental work presented here shed light on the rational elaboration of efficient nanocatalysts and contribute to the establishment of a circular carbon economy using green hydrogen.

关键词： ammonia borane hydrogen nanoalloy nanoreactor solid catalyst

Mechanism and experimental study on the fruit detachment of Chinese wolfberry through reciprocating vibration

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 47-58页

作者： song Mei Jinpeng wang Zhiyu song Dunbing Tang Cheng Shen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China Nanjing Forestry University Nanjing 210037China

In order to realize the efficient and high-quality mechanical picking for Chinese wolfberry,firstly,the forced reciprocating vibration picking principle of the Chinese wolfberry branch was studied,and the mechanical model of vibration picking was established based on the simplified cantilever model,and the response analysis and solution of all positions for the branch were carried *** the same time,the critical mechanical model of fruit detachment under the condition of fruit hanging on branches was established,and the theoretical values of inertia force for each component of the branch were ***,through actual measurement and finite element modeling,the natural frequency and forced vibration response simulation for each component of the branch of Chinese wolfberry terminal branch model were both studied,and the relationship between single-point periodic excitation force and high-quality fruit shedding parameters was ***,according to the conclusion of the picking model,a test bench with many groups of adjustable parameters was ***,the last branch of fruit-hanging Chinese wolf berry for Ningqi No.1 was taken as the experimental object,a four-level orthogonal experiment was designed with three factors:frequency,amplitude and entrance ***,the net picking rate,damage rate and false picking rate were taken as the evaluating indicators,referring to the comprehensive scores of the three *** was concluded that the primary and secondary relations of factors affecting the picking effect are frequency,amplitude and entrance angle,and the best operation parameters are frequency of 20 Hz,amplitude of 15 mm,and entrance angle of 45°,then,a hand-held vibration picker with setting parameters was trial-produced,and the optimal parameter combination was verified in the Chinese wolfberry planting base of the National Chinese wolfberry Engineering and Technology Research *** results showed that the net picking rate of rip

关键词： Chinese wolfberry branches reciprocating vibration inertial force orthogonal experiment

Online preparation of high-quality BN coatings with atomic diffusion based on carbon-free water-soluble precursor

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Journal of Advanced Ceramics 2024年第3期13卷 272-281页

作者： Yiang Du Bing wang Yunbo Zhang Quzhi song Fuwen wang Cheng Han Xiaoshan Zhang Yingde wang Science and Technology on Advanced Ceramic Fibers and Composites Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

Efficient and environmentally friendly production of high-quality continuous fiber coatings using current preparation methods is highly challenging due to issues such as scale and batch processing restrictions,low deposition rate,high energy consumption,and utilization of multiple environmentally hazardous *** address these challenges,we propose a stable and efficient wet chemical deposition coating method for high-throughput online continuous preparation of boron nitride(BN)coatings on ceramic fibers under an ambient *** process involves surface modification,in-situ wet chemical deposition,and heat treatment,and all seamlessly connecting with the ceramic fiber preparation process through continuous *** groups were introduced via surface modification enhancing wettability of the fiber surface with impregnating *** in-situ reaction and atom migration improve uniformity and binding of the *** a result,outstanding impregnation and adhesion properties are achieved.A comprehensive analysis to evaluate the impact of the BN coatings was conducted,which demonstrates that the BN-coated fibers exhibit a remarkable 36%increase in tensile strength,a 133%increase in fracture toughness,and enhanced temperature resistance of up to 1600℃.It provides a secure and efficient platform for cost-effective production of functional and high-quality coatings through targeted surface modification and rapid stretching impregnation.

关键词： polymer-derived ceramics SiC fibers wet chemical deposition atomic diffusion boron nitride(BN)coatings

E2E-MFERC:AMulti-Face Expression Recognition Model for Group Emotion Assessment

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Computers, Materials & Continua 2024年第4期79卷 1105-1135页

作者： Lin wang Juan Zhao Hu song Xiaolong Xu Jiangsu Key Laboratory of Big Data Security&Intelligent Processing Nanjing University of Posts and TelecommunicationsNanjing210042China School of Network Security Jinling Institute of TechnologyNanjing211169China State Grid Jiangsu Electric Power Company Limited Nanjing210000China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing210042China

In smart classrooms, conducting multi-face expression recognition based on existing hardware devices to assessstudents’ group emotions can provide educators with more comprehensive and intuitive classroom effect analysis,thereby continuouslypromotingthe improvementof teaching ***,most existingmulti-face expressionrecognition methods adopt a multi-stage approach, with an overall complex process, poor real-time performance,and insufficient generalization ability. In addition, the existing facial expression datasets are mostly single faceimages, which are of low quality and lack specificity, also restricting the development of this research. This paperaims to propose an end-to-end high-performance multi-face expression recognition algorithm model suitable forsmart classrooms, construct a high-quality multi-face expression dataset to support algorithm research, and applythe model to group emotion assessment to expand its application value. To this end, we propose an end-to-endmulti-face expression recognition algorithm model for smart classrooms (E2E-MFERC). In order to provide highqualityand highly targeted data support for model research, we constructed a multi-face expression dataset inreal classrooms (MFED), containing 2,385 images and a total of 18,712 expression labels, collected from smartclassrooms. In constructing E2E-MFERC, by introducing Re-parameterization visual geometry group (RepVGG)block and symmetric positive definite convolution (SPD-Conv) modules to enhance representational capability;combined with the cross stage partial network fusion module optimized by attention mechanism (C2f_Attention),it strengthens the ability to extract key information;adopts asymptotic feature pyramid network (AFPN) featurefusion tailored to classroomscenes and optimizes the head prediction output size;achieves high-performance endto-end multi-face expression detection. Finally, we apply the model to smart classroom group emotion assessmentand provide design refe

关键词： Multi-face expression recognition smart classroom end-to-end detection group emotion assessment

Genetic relationship between formation,accumulation and migration and dispersion of peat materials in Paleogene——Take the Qiongdongnan Basin as an example

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Acta Oceanologica Sinica 2024年第4期43卷 80-91页

作者： Xiaojing Li Zengxue Li Dongdong wang Guangzeng song Pingli wang Haiyan Liu Key Laboratory of Sedimentary Mineralization and Sedimentary Minerals in Shandong Province Qingdao 266590China Shandong University of Science and Technology Qingdao 266590China School of Water Conservancy and Environment University of JinanJinan 250022China

Coal-type source rocks include both coal and terrigenous marine source *** studying the distribution of secondary depressions,uplifts,as well as the characteristics of peat formation and accumulation in the northern marginal sea basin of the South China Sea,and combining them with coal formation characteristics observed in other basins,five genetic theories on the relationship between peat accumulation and dispersed organic matter accumulation are *** northern marginal sea basin of the South China Sea is characterized by“disadvantageous coals formation and favorable terrigenous marine source rocks formation.”This paper provides a distribution map of coal seams and terrigenous marine source rocks in the Qiongdongnan Basin and determines their distribution *** shows that the migration of sedimentary facies in the basins and inner depressions led to the formation and migration of the peat accumulation *** addition,the vertical migration of the peat accumulation centers led to planar migration,which is actually a type of coupling *** research results have revealed that the formation of coal-type source rock is *** marginal sea basin is composed of several fault-depression basins,with each basin developing a second order of depression and *** is no unified basin center or depositional center to be *** a result,the concentration centers of coal-forming materials also vary *** on the distribution characteristics of coal-type source rocks in different basins within the marginal sea basins of the South China Sea,the research results have practical significance and provide guidance for exploring coal-type oil and gas reservoirs in this area.

关键词： Coal-type source rock marginal sea basins migration of peat aggregation centers terrigenous marine source rock Qiongdongnan Basin

A method to interpret fracture aperture of rock slope using adaptive shape and unmanned aerial vehicle multi-angle nap-of-the-object photogrammetry

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 924-941页

作者： Mingyu Zhao Shengyuan song Fengyan wang Chun Zhu Dianze Liu Sicong wang College of Construction Engineering Jilin UniversityChangchun130026China College of Geo-Exploration Science and Technology Jilin UniversityChangchun130026China Institute of Engineering Geology and Geohazards Hohai UniversityNanjing210098China

The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock *** conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous *** study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of *** opening morphology is characterized using coordinate projection and *** central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture *** feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,*** study shows that the fracture aperture has a significant interval effect and size *** optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling *** fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear *** aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be *** of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma *** study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.

关键词： Unmanned aerial vehicle(UAV) photogrammetry High-steep rock slope Fracture aperture Interval effect Size effect Parameter interpretation

Monocular Distance Estimated Based on PTZ Camera

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Computers, Materials & Continua 2024年第5期79卷 3417-3433页

作者： Qirui Zhong Xiaogang Cheng Yuxin song Han wang Bell Honors School Nanjing University of Posts and Telecommunications Nanjing210003China College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation and College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing210003China

This paper introduces an intelligent computational approach for extracting salient objects fromimages and estimatingtheir distance information with PTZ (Pan-Tilt-Zoom) cameras. PTZ cameras have found wide applications innumerous public places, serving various purposes such as public securitymanagement, natural disastermonitoring,and crisis alarms, particularly with the rapid development of Artificial Intelligence and global infrastructuralprojects. In this paper, we combine Gauss optical principles with the PTZ camera’s capabilities of horizontal andpitch rotation, as well as optical zoom, to estimate the distance of the *** present a novel monocular objectdistance estimation model based on the Focal Length-Target Pixel Size (FLTPS) relationship, achieving an accuracyrate of over 95% for objects within a 5 km range. The salient object extraction is achieved through a simplifiedconvolution kernel and the utilization of the object’s RGB features, which offer significantly faster computingspeeds compared to Convolutional Neural Networks (CNNs). Additionally, we introduce the dark channel beforethe fog removal algorithm, resulting in a 20 dB increase in image definition, which significantly benefits distanceestimation. Our system offers the advantages of stability and low device load, making it an asset for public securityaffairs and providing a reference point for future developments in surveillance hardware.

关键词： Public security location information PTZ camera image processing

Damage Characteristics Analysis and Fractal Study of Shale With Prefabricated Fractures under Thermal-mechanical Coupling

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 570-586页

作者：张辉邬忠虎 song Huailei wang Wentao TANG Motian CUI Hengtao College of Civil Engineering Guizhou UniversityGuiyang 550025China

To study the damage and failure of shale with different fracture inclination angles under uniaxial compression loading,in this work,RFPA2D-Thermal,a two-dimensional real failure process analysis software,was used for numerical *** simulation results show that quartz in shale mainly affects the tensile and compressive strength of shale by increasing rock *** coupling of temperature and pressure will cause lateral and volume destruction of shale,which enables the shale body to be more easily *** inclination is the key factor affecting shale damage *** failure mode of shale with low-and high-angle fractures is mainly shear failure,and the compressive strength does not vary with crack *** damage mode of obliquely intersecting fractured shale is slip damage along the fracture face,the compressive strength decreases and then increases with the fracture inclination,and a minimum value *** acoustic emission simulation results of the damage process effectively reflect the accumulated internal damage and macroscopic crack appearance until fracture instability when the prefabricated fractured shale is subjected to uniaxial compressive *** crack inclinations of 0°and 120℃ corresponds to the most complex"N"shape damage *** crack inclinations of 30°and 60°,and the damage mode is an inverted"λ"shape.

关键词： shale temperature and pressure numerical simulation fracture dip angle fractal dimension

Multi-locomotion transition of tensegrity mobile robot under different terrains

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Science China(Technological Sciences) 2024年第2期67卷 536-557页

作者： YANG Qi LIU XinYu wang PanFeng song YiMin SUN Tao Key Laboratory of Mechanism Theory and Equipment Design(Tianjin University) Ministry of EducationTianjin UniversityTianjin 300350China

Knowing how to make a multi-locomotion robot achieve locomotion transition under different terrains is a challenging problem,especially for tensegrity robots with multi-locomotion *** this study,a motion planning method for the transition of a multi-locomotion tensegrity robot(hereafter TJUBot)under different terrains is *** robot can achieve four locomotion modes:earthworm-like,inchworm-like,tumbling,and sliding locomotion with only two *** models of the four locomotion modes under five typical terrains,including flat ground,confined space,obstacle,gap,and descending slope,are established using the energy ***,the kinematic characteristics(driving law and initial position)of the robot under these terrains are *** this basis,motion planning for the locomotion transition of TJUBot is conducted,which includes a perception strategy based on three laser sensors and a transition strategy under different *** driving laws of the two motors that can ensure the effective locomotion transition of TJUBot under different terrains are naturally ***,experiments are *** demonstrate that the robot can achieve effective locomotion transition when the motion planning method is used.

关键词： multi-locomotion robot tensegrity kinematic modeling locomotion transition