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Zinc modification of Ni-Ti as efficient Ni_(x)Zn_(y)Ti_(1)catalysts with both geometric and electronic improvements for hydrogenation of nitroaromatics

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Frontiers of Chemical Science and engineering 2022年第4期16卷 461-474页

作者： Pingle Liu Yu Liu Yang Lv Wei Xiong Fang Hao Hean Luo College of Chemical Engineering National&Local United Engineering Research Center for Chemical Process Simulation and IntensificationXiangtan UniversityXiangtan 411105China

The catalytic hydrogenation of nitroaromatics is an environmentally friendly technology for aniline production,and it is crucial to develop noble-metal-free catalysts that can achieve chemoselective hydrogenation of nitroaromatics under mild reaction *** this work,zinc-modified Ni-Ti catalysts(Ni_(x)Zn_(y)Ti_(1))were fabricated and applied for the hydrogenation of nitroaromatics *** was found that the introduction of zinc effectively increases the surface Ni density,enhances the electronic effect,and improves the interaction between Ni and TiO_(2),resulting in smaller Ni particle size,more oxygen vacancies,higher dispersion and greater concentration of Ni on the catalyst ***,the electron-rich Ni^(δ-) obtained by electron transfer from Zn and Ti to Ni effectively adsorbs and dissociates *** results reveal that Ni_(x)Zn_(y)Ti_(1)(Ni_(0.5)Zn_(0.5)Ti_(1))shows excellent catalytic performance under mild conditions(70℃and 6 bar).These findings provide a rational strategy for the development of highly active non-noble-metal hydrogenation catalysts.

关键词： bimetal strategy oxygen vacancy non-noble metal catalyst hydrogenation aromatic nitro compounds

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Fractal autoencoder with redundancy regularization for unsupervised feature selection

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Science China(Information Sciences) 2025年第2期68卷 89-102页

作者： Meiting SUN Fangyu LI Honggui HAN School of Information Science and Technology Beijing University of Technology Beijing Key Laboratory of Computational Intelligence and Intelligent System Engineering Research Center of Digital Community Ministry of Education Beijing Institute of Artificial Intelligence

Feature selection is a crucial step in data preprocessing because feature selection reduces the dimensionality of data by eliminating irrelevant and redundant features. Since manual labeling is expensive, unsupervised feature selection has received increasing attention in recent years. However, existing unsupervised feature selection methods tend to prioritize selecting highly correlated features over exploring feature diversity. Thus, a regularized fractal autoencoder(RFAE) method is proposed to select informative features in an unsupervised way. Specifically, the fractal autoencoder network extends autoencoders to construct a correspondence neural network and a selection neural network. The correspondence neural network exploits interfeature correlations and the selection neural network selects the informative features. A redundancy regularization strategy consists of a redundancy elimination regularization term based on the dependency between features and a sparse regularization term based on the group lasso. The redundancy regularization strategy eliminates feature subset redundancy and enhances network generalization ability. Extensive experimental results on six publicly available datasets show that the proposed RFAE outperforms the compared methods regarding clustering accuracy and classification accuracy. Moreover, the proposed RFAE achieves acceptable computation efficiency.

关键词： unsupervised feature selection fractal autoencoder correspondence neural network selection neural network redundancy regularization strategy

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Cleaner production of 3.5 valent vanadium electrolyte from ammonium metavanadate by ammonia reduction-sulfuric acid dissolution method

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Tungsten 2024年第3期6卷 555-560页

作者： Cheng Wang Lan-Jie Li Hao Du College of Chemical Engineering University of Chinese Academyof SciencesBeijing100049China Institute of Process Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesChinese Academy of SciencesBeijing 100190China Hesteel Group Company Limited Shijiazhuang 050023China

The vanadium redox flow battery(VRFB)has been widely used in large-scale energy storage areas due to the advantages of long lifespan and high ***,the high preparation cost of vanadium electrolyte limits the largescale... 详细信息

关键词： vanadium electrolyte Clean

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Depositing the PtNi nanoparticles on niobium oxide to enhance the activity and CO-tolerance for alkaline methanol electrooxidation

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Chinese Journal of Structural Chemistry 2023年第11期42卷 25-31页

作者： Xinyi Hu Riguang Zhang Zhao Jiang Department of Chemical Engineering Shaanxi Key Laboratory of Energy Chemical Process IntensificationEngineering Research Center of New Energy System Engineering and Equipment Xi'an Jiaotong UniversityXi'an710049China State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan030000China

Direct methanol fuel cells have the advantages of simple system,convenient operation,high conversion rate and low carbon emission,which are considered as the environmental and friendly energy conversion ***-ever,the low activity,CO-tolerance and high cost of anode catalysts restrict the large-scale commercial ***,it is of great practical significance to design and construct the anodic catalysts with high activity,stability and low cost for methanol oxidation *** this work,the PtM/Nb_(2)O_(5)-C(M=Co,Sn,Ni)catalysts are synthesized by the ethylene glycol solvothermal method using transition metal oxide Nb_(2)O_(5)as the *** catalytic performance of different catalysts is further evaluated for alkaline *** results show that the introduction of Ni(existing in Ni^(2+)and Ni^(3+))has the most obvious improvement for alkaline MOR *** adjusting the doped ratio of Pt:Ni,it is shown that PtNi/Nb_(2)O_(5)-C has the highest mass activity(3877.9 mA-mg_(pt)^(-1)),12 times that of the commercial Pt/C ***,LSV,Tafel and EIS analyses show that PtNi/Nb_(2)O_(5)-C has the lowest onset potential and charge transfer resistance,and the fastest electrocatalytic oxidation rate of *** tests show that the electrochemical stability is also significantly improved with the introduction of Nb_(2)O_(5)and *** with the structural characterization and electrochemical tests,it is found that the evident electronic effect among Pt and Ni,Nb_(2)O_(5)and the hydroxyl brought from Ni species are mainly ascribed for enhancing the activity,CO resistance and stability of PtNi/Nb_(2)O_(5)-C.

关键词： Direct methanol fuel cell Niobium oxide Platinum-based catalysts Methanol oxidation reaction

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Underwater Target Capture based on Heterogeneous Unmanned system Collaboration

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-14页

作者： Cao, Xiang Liu, Wenzhang Ren, Lu School of Artificial Intelligence Anhui University Hefei China Engineering Research Center of Autonomous Unmanned System Technology Ministry of Education Hefei China

Due to motion constraints, an underwater unmanned vehicle (UUV) is not sufficient to efficiently complete large-scale underwater target capture tasks. By coordinating multiple unmanned devices, the success rate of target capture can be greatly improved. Compared to the collaboration of homogeneous unmanned devices, the collaboration of heterogeneous unmanned devices can provide more abundant spatiotemporal information, which helps to better accomplish the tasks. To improve work efficiency, this paper proposes a strategy for underwater target capture based on the collaboration of heterogeneous unmanned devices. Firstly, a heterogeneous unmanned system composed of unmanned aerial vehicle (UAV), unmanned surface vehicle (USV), and UUVs is designed for the task of target capture. Secondly, under the constraints of communication and energy, a full coverage path planning scheme for the collaboration of UAV and USV is proposed to increase the observation range of UAV within a unit of time. Finally, the UUVs utilize an adaptive grey wolf optimizer (GWO) algorithm to capture the underwater target. Simulation results demonstrate that the efficiency of target capture is improved through the collaboration of UAV, USV, and UUVs. The proposed adaptive GWO algorithm effectively addresses the issue of premature convergence in the target capture process. IEEE

关键词： Motion planning

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Enhancing the high-temperature corrosion resistance of HVOF-sprayed NiCoCrAlY coating in marine environment by Pt modification and pre-oxidation

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Journal of Materials Science & Technology 2024年第34期201卷 222-235页

作者： Y.Y.Li Y.M.Jiang C.Zhang H.Z.Ji S.Li N.Xu Z.B.Bao S.L.Zhu F.H.Wang School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering No.703 Research Institute of CSSCHarbin 150078China Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China

To prolong the service lifetime of hot-section components used in marine environment at elevated tem-peratures,it is crucial to explore and develop high-temperature corrosion-resistant ***-velocity oxygen fuel(HVOF)sprayed NiCoCrAlY,Pt-modified NiCoCrAlY and pre-oxidized Pt-modified NiCoCrAlY coatings were prepared and *** study is concerned with the performance of three coat-ings in a simulated marine environment based on the phase composition of corrosion products and mi-crostructure evolution of coating samples combined with first-principles density functional *** results show that the NiCoCrAlY coating was subject to accelerated corrosion and extensive aluminum depletion,leading to premature coating *** high-temperature corrosion resistance of Pt-modified NiCoCrAlY coating was found to be better than that of NiCoCrAlY *** contrast,the pre-oxidized Pt-modified NiCoCrAlY coating offered long-lasting protection and exhibited the best corrosion resistance,which is attributed to the positive synergistic effect between Pt modification and pre-oxidation.

关键词： High-temperature corrosion HVOF-sprayed MCrAlY coating Pt modification Pre-oxidation marine environment

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A review of updated S-scheme heterojunction photocatalysts

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Journal of Materials Science & Technology 2024年第10期177卷 142-180页

作者： Fangyi Li Guihua Zhu Jizhou Jiang Lang Yang Fengxia Deng Arramel Xin Li School of Environmental Ecology and Biological Engineering Key Laboratory of Green Chemical Engineering Process of Ministry of EducationEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationNovel Catalytic Materials of Hubei Engineering Research CenterWuhan Institute of TechnologyWuhan 430205China National Engineering and Technology Research Center for Development&Utilization of Phosphate Resources Kunming 650600China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China Nano Center Indonesia Jalan Raya PUSPIPTEKSouth TangerangBanten 15314Indonesia Institute of Biomass Engineering Key Laboratory of Energy Plants Resource and UtilizationMinistry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China

Photocatalysis is a green and environmentally-friendly process that utilizes the ubiquitous intermittent *** date,an emerging S-scheme heterojunction across the intimately coupled heterojunction materials is proposed to surpass the efficiency of conventional Ⅱ-type and Z-type ***-more,S-scheme heterojunction photocatalysts with greatly improved photocatalytic performance have gained significant attention due to their fast charge carriers separation along with strong redox ability and stability,since its proposal in ***,a timely and comprehensive review is highly desired to cover the state-of-the-art *** by this idea,the review conveys the recent progress and provides new insights into further *** the conventional method,in this review,we im-plement a quantification model to outline current trends in S-scheme heterojunctions research as well as their *** overview begins with the fundamentals of four basic photocatalytic mechanisms,followed by its design ***,diverse characterization techniques used in the S-scheme heterojunctions are systematically summarized along with the modification strategies to boost photocat-alytic ***,the internal reaction mechanism and emerging applications have been reviewed,including water conversion,CO_(2) remediation,wastewater treatment,H_(2)0_(2) production,N_(2) fix-ation,*** sum up the review,we present several current challenges and future prospects of the S-scheme heterojunctions photocatalysts,aiming to provide indispensable platforms for the future smart design of photocatalysts.

关键词： S-scheme heterojunctions Photocatalysts Modification strategies Charge separation mechanism

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Intelligent recognition and information extraction of radar complex jamming based on time-frequency features

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Journal of systems engineering and Electronics 2024年第5期35卷 1148-1166页

作者： PENG Ruihui WU Xingrui WANG Guohong SUN Dianxing YANG Zhong LI Hongwen College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China Qingdao Innovation and Development Center Harbin Engineering UniversityQingdao 266000China Information Fusion Research Institute Naval Aeronautical UniversityYantai 264001China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhan 430033China

In modern war,radar countermeasure is becoming increasingly fierce,and the enemy jamming time and pattern are changing more *** is challenging for the radar to efficiently identify jamming and obtain precise parameter information,particularly in low signal-to-noise ratio(SNR)*** this paper,an approach to intelligent recognition and complex jamming parameter estimate based on joint time-frequency distribution features is proposed to address this challenging ***,a joint algorithm based on YOLOv5 convolutional neural networks(CNNs)is proposed,which is used to achieve the jamming signal classification and preliminary parameter ***,an accurate jamming key parameters estimation algorithm is constructed by comprehensively utilizing chi-square statistical test,feature region search,position regression,spectrum interpolation,etc.,which realizes the accurate estimation of jamming carrier frequency,relative delay,Doppler frequency shift,and other ***,the approach has improved performance for complex jamming recognition and parameter estimation under low SNR,and the recognition rate can reach 98%under−15 dB SNR,according to simulation and real data verification results.

关键词： complex jamming recognition time frequency feature convolutional neural network(CNN) parameter estimation

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Deflection of cavitation bubble near the rigid wall with a gas-containing hole

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Journal of Hydrodynamics 2023年第2期35卷 330-337页

作者： Yu-rong Sun Qiang Zhong Zhi-feng Yao Dan Zi Ruo-fu Xiao Fu-jun Wang College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System Beijing100083China

The presence of a rigid wall causes a microjet of the cavitation bubble to collapse to move toward the wall,while a free surface does the *** a rigid wall surface is combined with a free surface,it may affect the direction of the *** motive of this study is to find out the influence of the dynamic behavior of a laser-induced bubble near the rigid wall with a gas-containing *** of the bubble at different distances from the gas-containing hole in the horizontal and vertical directions were recorded by a high-speed camera(2.3×10^(5) fps).When the bubble collapse near the boundary,the bubble will produce two situations:away from or toward the *** focuses on the direction of the bubble,the oscillation period of a bubble,and reflection angle,and quantitative analysis of the *** was found that the boundary not only changes the morphologic of the bubble and the overall direction of movement but also affects the oscillation *** addition,it can control the deflection of the bubble.

关键词： Cavitation bubble bubble migration deflection angle gas-containing hole

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Speckle-free laser display enabled by self-assembled supraparticles of semiconductor nanoplatelets

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Nano research 2025年第2期18卷 769-775页

作者： Chenlin Wang Haixiao Zhao Xian Zhao Baoqing Sun Yuan Gao School of Information Science and Engineering Shandong UniversityQingdao 266237China Key Laboratory of Laser&Infrared System(Shandong University) Ministry of EducationShandong UniversityQingdao 266237China Center for Optics Research and Engineering(CORE) Shandong UniversityQingdao 266237China

Laser-based light sources are highly desirable for display applications due to their narrow emission linewidth and exceptional ***,the coherence inherent in lasers often leads to the formation of unwanted speckles,which can significantly degrade display ***,there is a critical need for light sources that retain the narrow emission and high brightness of lasers while minimizing spatial coherence to reduce speckle *** lasing has emerged as a promising strategy to address this issue,though its random emission directions can lead to energy *** overcome this challenge,we propose a novel approach in which CdSe nanoplatelets,known for their efficient optical gain properties,are self-assembled into supraparticles(SPs),serving as both scattering centers and gain *** configuration enables random lasing,and by coupling the random gain medium to a Fabry-Perot(FP)cavity,we successfully direct the typically omnidirectional random lasing into a controlled,low-coherence *** experimental results,comparing conventional lasers(e.g.,He:Ne lasers)with our SP-based laser for a projector,demonstrate effective suppression of speckle formation,reducing speckle contrast from 0.5 to *** findings offer a promising solution for improving the performance and quality of laser-based displays.

关键词： CdSe nanoplatelet self-assembly cavity coupled random lasing speckle-free display

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