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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

Boosting sodium-storage properties of hierarchical Na_(3)V_(2)(PO_(4))_(3)@C micro-flower cathodes by tiny Cr doping:The effect of“four ounces moving a thousand pounds”

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Nano Research 2024年第1期17卷 235-244页

作者： Yongjia Wang Guoshuai su Xiaoying Li Linrui Hou Longwei Liang Changzhou yuan School of Materials Science&Engineering University of JinanJinan 250022China

Na_(3)V_(2)(PO_(4))_(3)(NVP),as a great potential cathode candidate for Na-ion batteries(NIBs),has attracted enormous interest due to its three-dimensional(3D)large open framework for convenient Na+transport,yet its practical application is still limited by its inferior electron conductivity and sluggish Na+diffusion ***,the tiny Cr doped hierarchical NVP micro-flower cathodes(i.e.,Na_(3)V_(2-x)Crx(PO_(4))_(3)@C,x≤0.1),which are self-assembled with single-crystal nanoflake subunits in-situ coated with carbon nano-shell,are designed and fabricated via a scalable *** optimized cathode,i.e.,Na_(3)V_(1.94)Cr_(0.06)(PO_(4))_(3)@C(NVCP-6),was endowed with more electro-active Na(2)sites and higher electronic/ionic conductivity for efficient sodium *** from these competitive merits,the NVCP-6,when evaluated as a cathode towards NIBs,exhibits an ultrahigh-rate capability of 99.8 mAh·g^(-1)at 200 C and superior stability of 82.2%over 7300 cycles at 50 ***,the NVCP-6 based full NIBs display remarkable electrochemical properties in terms of both high-rate capacities and long-duration cycling properties at different temperatures(-20–50°C).The contribution,i.e.,the design of“four ounces can move a thousand pounds”,here will promote the practical industrial application of NVP towards advanced NIBs.

关键词： Na_(3)V_(2)(PO_(4))_(3)cathode tiny Cr doping active Na sites ultrahigh-rate capability Na-ion batteries

Transfer matrix method for free and forced vibrations of multi-level functionally graded material stepped beams with different boundary conditions

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 983-1000页

作者： Xiaoyang su Tong HU Wei ZHANG Houjun KANG Yunyue CONG Quan yuan School of Civil Engineering and Architecture Guangxi UniversityNanning 530004China Scientific Research Center of Engineering Mechanics Guangxi UniversityNanning 530004China State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures Guangxi UniversityNanning 530004China

Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical *** study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving *** the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable ***,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are *** demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also *** this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried *** results show the accuracy and efficiency of the TMM.

关键词： transfer matrix method(TMM) free vibration forced vibration functionally graded material(FGM) stepped beam

Cobalt-nitrogen co-doped porous carbon sphere as highly efficient catalyst for liquid-phase cyclohexane oxidation with molecular oxygen and the active sites investigation

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 101-112页

作者： Lei Chen yuan sun Jinshan Chi Wei Xiong Pingle Liu fang Hao College of Chemical Engineering National&Local United Engineering Research Centre for Chemical Process Simulation and IntensificationXiangtan UniversityXiangtan411105China

The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol(KA oil)is a challenging issue in the chemical *** present the industrial conversion of cyclohexane to cyclohexanone and cyclohexanol is normally controlled at less than 5%***,the development of highly active and stable catalysts for the aerobic oxidation of cyclohexane is necessary to overcome this low-efficiency ***,we have developed a cobalt-nitrogen co-doped porous sphere catalyst,Co-NC-x(x is the Zn/Co molar ratio,where x=0,0.5,1,2,and 4)by pyrolyzing resorcinol-formaldehyde resin *** achieved 88.28%cyclohexanone and cyclohexanol selectivity and a cyclohexane conversion of 8.88%under *** results showed that the introduction of zinc effectively alleviated the aggregation of Co nanoparticles and optimized the structural properties of the *** addition,Co0 and pyridinic-N are proposed to be the possible active species,and their proportion efficiently increased in the presence of Zn^(2+)*** this study,we developed a novel strategy to design highly active catalysts for cyclohexane oxidation.

关键词： KA oil production cyclohexane selective oxidation cobalt-nitrogen co-doped porous carbon spheres metal-organic framework

Polypore funga and species diversity in tropical forest ecosystems of Africa,America and Asia,and a comparison with temperate and boreal regions of the Northern Hemisphere

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Forest Ecosystems 2024年第4期11卷 391-400页

作者： Heng Zhao Yingda Wu Zhirong Yang Honggao Liu fang Wu Yucheng Dai yuan yuan State Key Laboratory of Efficient Production of Forest Resources School of Ecology and Nature ConservationBeijing Forestry UniversityBeijing 100083China Key Laboratory of Forest and Grassland Fire Risk Prevention Ministry of Emergency ManagementChina Fire and Rescue InstituteBeijing 102202China Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic Biology Zhaotong UniversityZhaotong 657000China Yunnan Engineering Research Center of Green Planting and Processing of Gastrodia Zhaotong UniversityZhaotong 657000China

Polypores play a cru cial role in energy recycling and forest regeneration in forest *** majority of them are wood degraders;some are forest pathogens and others are ectomycorrhizal *** basidiocarps provide food and shelter for many organisms,mostly invertebrates,but also some vertebrates,as well as food and medicine for *** extensive research on the species diversity and phylogenetic relationships of polypores in recent years,there remains a lack of comprehensive understanding of their distribution patterns and species composition at the large *** of polypores from the tropical zone,including tropical Africa,tropical America,and tropical Asia,were analyzed for species diversity,distribution patterns,major taxa,and nutritional modes.A total of 1,902 polypore species was found in the three regions,representing 8 orders,46families,and 250 genera of *** orders Polyporales(especially the family Polyporaceae)and Hymenochaetales(especially the family Hymenochaetaceae)had the most prolific taxa,with their species accounting for 93.4%of the total polypores *** of 1,565(or 82.3%)of the total 1,902 species were found in only one of the three regions studied,and we treat them temporarily as"regional endemic species".Only 141species were shared among all three regions,accounting for a mere 7.4%.Tropical Africa and tropical America had the greatest number of shared species and the highest S?rensen similarity index(SC)*** forests had a higher species richness compared with temperate to boreal forests of the Northern Hemisphere,and in addition,also a higher proportion of white rot polypores compared to brown rot and ectomycorrhizal *** study outlines the distribution patterns and species diversity of polypores in the world,shedding light on their ecological significance in diverse ecosystems.

关键词： Agaricomycetes Macrofungi Species composition Wood-decay fungi

Molecular recognition of cyclophanes in water

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Chinese Chemical Letters 2024年第5期35卷 32-44页

作者： fang-yuan Chen Wen-Chao Geng Kang Cai Dong-Sheng Guo College of Chemistry State Key Laboratory of Elemento-Organic ChemistryKey Laboratory of Functional Polymer Materials(Ministry of Education)Frontiers Science Center for New Organic MatterCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai UniversityTianjin 300071China College of Chemistry Nankai UniversityTianjin 300071China

Molecular recognition in water,the biological solvent,always receives significant research focus in supramolecular *** mechanisms of molecular recognition in water is key to comprehending biological processes at the molecular *** the past five decades,supramolecular chemists have developed a vast array of synthetic receptors with highly diverse structures and recognition *** them,cyclophanes represent an important family of macrocyclic receptors that have been extensively *** aromatic moieties in cyclophanes not only facilitate chemical modifications to impart water solubility but also enable forming hydrophobic cavities for guest inclusion in aqueous *** by Koga et al.,who reported the first inclusion complex of cyclophanes in water and solid state,numerous water-soluble cyclophanes,including derivatives of blue box,calixarenes,resorcinarenes,pillararenes,octopusarenes,biphenarenes,coronarenes,and naphthotubes,etc.,have been synthesized and subjected to investigation of the recognition capabilities in aqueous *** review provides an overview of cyclophane receptors designed to bind organic guests in *** categorize them into two classes based on the modifications made to their hydrophobic cavities:those with“exo-functionalized hydrophobic cavities”and those with“endo-functionalized hydrophobic cavities”.We introduce their distinctive features and discuss strategies to enhance recognition affinity and *** review aims to inspire the development of novel synthetic receptors with intriguing properties and foster practical applications of cyclophanes.

关键词： Biomimetic receptor Cyclophane Molecular recognition Hydrophobic effect High-affinity Macrocycles

A confined growth strategy to construct 3DOM SiO_(2) nanoreactor insitu embedded Co_(3)O_(4) nanoparticles catalyst for the catalytic combustion of VOCs:superior H_(2)O and SO_(2) resistance

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Nano Research 2024年第1期17卷 207-220页

作者： Weigao Han Shilin Wu fang Dong Weiliang Han Yinghao Chu Linghui su Zhicheng Tang State Key Laboratory for Oxo Synthesis and Selective Oxidation National Engineering Research Center for Fine Petrochemical IntermediatesLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Dalian 116023China College of Architecture and Environment Sichuan UniversityChengdu 610000China

SO_(2)poisoning is a common problem in the catalytic combustion of volatile organic compounds(VOCs).In this work,we took three-dimensionally ordered macroporous and mesoporous(3DOM)SiO_(2)as the nanoreactor to protect active sites from SO_(2)erosion in the catalytic combustion of ***,the confined growth of metal active nanoparticles in the multi-stage pore is also full of *** we successfully confined Co_(3)O_(4)nanoparticles(NPs)in macroporous and mesoporous ***,the precursors’growth in the pore was controlled and nanoreactors with different pore sizes were prepared by adjusting the loading amount and preparation *** is discovered that the Co_(3)O_(4)NPs confined in 3DOM SiO_(2)nanoreactor showed superior sulfur and water *** functional theory(DFT)calculations verified that the Co-Si catalyst had high SO_(2)adsorption energy(-0.48 eV),which illustrated that SO_(2)was hard to attach to the surface of the Co-Si *** SiO_(2)nanoreactor had low SO_(2)adsorption energy(-5.15 eV),which indicated that SO_(2)was easily absorbed on SiO_(2)*** illustrated that the SiO_(2)nanoreactor could protect effectively active sites from SO_(2)erosion.

关键词： zeolitic imidazolate frameworks(ZIFs) Co_(3)O_(4) benzene catalytic combustion nanoreactor sulfur and water resistance

Orbital angular momentum-mediated machine learning for high-accuracy mode-feature encoding

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Light(Science & Applications) 2024年第3期13卷 466-477页

作者： Xinyuan fang Xiaonan Hu Baoli Li Hang su Ke Cheng Haitao Luan Min Gu Institute of Photonic Chips University of Shanghai for Science and TechnologyShanghai 200093China Centre for Artificial-Intelligence Nanophotonics School of Optical-Electrical and Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China

Machine learning with optical neural networks has featured unique advantages of the information processing including high speed,ultrawide bandwidths and low energy consumption because the optical dimensions(time,space,wavelength,and polarization)could be utilized to increase the degree of ***,due to the lack of the capability to extract the information features in the orbital angular momentum(OAM)domain,the theoretically unlimited OAM states have never been exploited to represent the signal of the input/output nodes in the neural network ***,we demonstrate OAM-mediated machine learning with an all-optical convolutional neural network(CNN)based on Laguerre-Gaussian(LG)beam modes with diverse diffraction *** proposed CNN architecture is composed of a trainable OAM mode-dispersion impulse as a convolutional kernel for feature extraction,and deep-learning diffractive layers as a *** resultant OAM mode-dispersion selectivity can be applied in information mode-feature encoding,leading to an accuracy as high as 97.2%for MNIST database through detecting the energy weighting coefficients of the encoded OAM modes,as well as a resistance to eavesdropping in point-to-point free-space ***,through extending the target encoded modes into multiplexed OAM states,we realize all-optical dimension reduction for anomaly detection with an accuracy of 85%.Our work provides a deep insight to the mechanism of machine learning with spatial modes basis,which can be further utilized to improve the performances of various machine-vision tasks by constructing the unsupervised learning-based auto-encoder.

关键词： polarization mode momentum

Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-Hui Tang Na Zhang Wei Bao Wei Jiang yuan Lin Zhao-Hui su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles