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Three-dimensional(3D)parametric measurements of individual gravels in the Gobi region using point cloud technique

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Journal of Arid Land 2024年第4期16卷 500-517页

作者： JING Xiangyu HUANG Weiyi KAN Jiangming College of Engineering Beijing Forestry UniversityBeijing 100083China Key laboratory of State Forestry Administration on Forestry Equipment and Automation Beijing 100083China

Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed *** presence significantly influences the movement of sand and ***,the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi *** is challenging to describe these processes according to a uniform ***,it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional(3D)size and shape of *** morphology information for Gobi gravels is essential for studying its genesis and sand *** enhance the efficiency and information yield of gravel parameter measurements,this study conducted field experiments in the Gobi region across Dunhuang City,Guazhou County,and Yumen City(administrated by Jiuquan City),Gansu Province,China in March 2023.A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed,alongside improved calculation formulas for 3D parameters including gravel grain size,volume,flatness,roundness,sphericity,and equivalent grain *** multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear ***,the proposed methodology incorporated point cloud clustering,segmentation,and filtering techniques to isolate individual gravel point *** point cloud algorithms,including the Oriented Bounding Box(OBB),point cloud slicing method,and point cloud triangulation,were then deployed to calculate the 3D parameters of individual *** systematic processes allow precise and detailed characterization of individual *** gravel grain size and volume,the correlation coefficients between point cloud and manual measurements all exceeded 0.9000,confirming the feasibility of the proposed methodol

关键词： Gobi gravels three-dimensional(3D)parameters point cloud 3D reconstruction Random Sample Consensus(RANSAC)algorithm Density-Based Spatial Clustering of Applications with Noise(DBSCAN)

Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

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Particuology 2024年第6期89卷 117-130页

作者： Chaoyu Yan Yue Yuan Xiaoyang Wei Jesse Zhu State Key laboratory of Heavy Oil Processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons Institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity *** fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical *** the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent ***,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent *** transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom *** wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency *** sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized *** micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale *** work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

Enhancing Green Ammonia Electrosynthesis Through Tuning Sn Vacancies in Sn‑Based MXene/ MAX Hybrids

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Nano-Micro Letters 2024年第5期16卷 154-168页

作者： Xinyu Dai Zhen‑Yi Du Ying Sun Ping Chen Xiaoguang Duan Junjun Zhang Hui Li Yang Fu Baohua Jia Lei Zhang Wenhui Fang Jieshan Qiu Tianyi Ma Key laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province College of ChemistryInstitute of Clean Energy ChemistryLiaoning UniversityShenyang 110036People’s Republic of China State Key laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024People’s Republic of China School of Chemistry and Chemical Engineering Anhui UniversityHefei 230601People’s Republic of China School of Chemical Engineering The University of AdelaideAdelaideSA 5005Australia State Key laboratory of High‑Efficiency Utilization of Coal and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021NingxiaPeople’s Republic of China School of Science RMIT UniversityMelbourneVIC 3000Australia Guangdong Provincial Key laboratory of Advanced Energy Storage Materials School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640People’s Republic of China College of Chemical Engineering State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia ***,relevant out-lab research is still in its ***,a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies,Sn@Ti_(2)CTX/Ti_(2)SnC–V,was synthesized by controlled etching Sn@Ti_(2)SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N2 *** to the synergistic effect of MXene/MAX heterostructure,the existence of Sn vacancies and the highly dispersed Sn active sites,the obtained Sn@Ti2CTX/Ti_(2)SnC–V exhibits an optimal NH_(3) yield of 28.4μg h^(−1) mg_(cat)^(−1) with an excellent FE of 15.57% at−0.4 V versus reversible hydrogen electrode in 0.1 M Na_(2)SO_(4),as well as an ultra-long ***,this catalyst represents a satisfactory NH3 yield rate of 10.53μg h^(−1) mg^(−1) in the home-made simulation device,where commercial electrochemical photovoltaic cell was employed as power source,air and ultrapure water as feed *** as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic *** work is of significance for large-scale green ammonia production.

关键词： Green ammonia synthesis N2 electroreduction Renewable energy Sn MXene/MAX hybrid

A Magnetic-Multiplier-Enabled Hybrid Generator with Frequency Division Operation and High Energy Utilization Efficiency

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Research 2024年第1期2023卷 561-570页

作者： Jie Chen Kangjie Wu Shaokun Gong Jianchao Wang Ke Wang Hengyu Guo College of Physics and Electronic Engineering Chongqing Key Laboratory Photo-electric Functional MaterialsChongqing Normal UniversityChongqing 401331China State Key laboratory of Mechanical Transmission College of Mechanical and Vehicle EngineeringChongqing UniversityChongqing 400044China School of Physics Chongqing UniversityChongqing 400044China

The hybrid electromagnetic-triboelectric generator(HETG)is a prevalent device for mechanical energy ***,the energy utilization efficiency of the electromagnetic generator(EMG)is inferior to that of the triboelectric nanogenerator(TENG)at low driving frequencies,which limits the overall efficacy of the *** tackle this issue,a layered hybrid generator consisting of a rotating disk TENG,a magnetic multiplier,and a coil panel is *** magnetic multiplier not only forms the EMG part with its high-speed rotor and the coil panel but also facilitates the EMG to operate at a higher frequency than the TENG through frequency division *** systematic parameter optimization of the hybrid generator reveals that the energy utilization efficiency of EMG can be elevated to that of rotating disk *** a power management circuit,the HETG assumes the responsibility for monitoring the water quality and fishing conditions by collecting low-frequency mechanical *** magneticmultiplier-enabled hybrid generator demonstrated in this work offers a universal frequency division approach to improve the overall outputs of any hybrid generator that collects rotational energy,expanding its practical applications in diverse multifunctional self-powered systems.

关键词： generator rotating assume

Comparison of the precision of glacier flow rates derived from offset-tracking using Sentinel-2 and Landsat-8/9 imagery

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Advances in Polar Science 2024年第2期35卷 238-251页

作者： YANG Zhibin CHEN Zhuoqi LI Gang MAO Yanting FENG Xiaoman CHENG Xiao School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Key laboratory of Comprehensive Observation of Polar Environment(Sun Yat-sen University) Ministry of EducationZhuhai 519082China

Offset-tracking is an essential method for deriving glacier flow rates using optical ***-2(S2)and Landsat-8/9(L8/9)are popular optical satellites or constellations for polar studies,offering high spatial resolution with relatively short revisit time,wide swath width,and free *** evaluate and compare the precision of offset-tracking results yielded with these two kinds of data,in this study S2 and L8/9 imagery observed in Petermann Glacier in Greenland,Karakoram in High-Mountains Asia,and Amery Ice Shelf in the Antarctic are *** and various systematic error sources in the offset-tracking results including orbital and strip errors were analyzed and eliminated at the pre-process *** at the off-glacier(bare rock)region was evaluated by presuming that no deformation occurred;then for both glacierized and the off-glacier regions,precision of velocity time series was evaluated based on error propagation *** least squares method based on connected components was used to solve flow rates time series based on multi-pair images *** results indicated that S2 achieved slightly higher precision than L8/9 in terms of both single-pair derived displacements and least square solved daily flow rates time ***,the RMSE of daily velocity is 26%lower for S2 than L8/***,S2 provided higher temporal resolution for monitoring glacier flow rates.

关键词： Sentinel-2 Landsat glacier flow rates offset-tracking precision

Variations of 18S rDNA Loci Among Six Populations of Paeonia obovata Maxim. （Paeoniaceae） Revealed by Fluorescence In Situ Hybridization

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Journal of Integrative Plant Biology 2006年第5期48卷 497-502页

作者： Rui Luo Chao Wang Daming Zhang State Key laboratory of systematic and Evolutionary Botany Institute of Botany the Chinese Academy of Sciences Beijing 100093 China

The localization of 18S ribosomal RNA genes （rDNA） by fluorescence in situ hybridization （FISH） had been performed for some species of Paeonla. However, the pattern of 18S rDNA loci among populations Is Indistinct. In the present study, we localized 18S rDNA loci on meiotic or mitotic chromosomes of six populations of Paeonla obovata Maxim. （Paeonlaceae）. Different numbers of rDNA loci were found with different diploid （2n=10） populations, namely eight （Lushl and Mt. JIuhua populations）, 10 （Mt. Talbal population）, and seven （Mt. Guandl population）, whereas tetraplold （2n=20） populations were all found with 16 loci. Aii rDNA loci were mapped near teiomeres of mitotic chromosomes and there was no chromosome with two loci. The present results show that molecular cytological polymorphlsm exists among P. obovata diploid populations, Indicating that structural variations occurred frequently during the evolutionary history of this species, accompanied with differentiation among populations.

关键词： cytotype fluorescence in situ hybridization (FISH) Paeonia obovata 18S rDNA tetraploid.

Excitonic Instability in Ta2Pd3Te5 Monolayer

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Chinese Physics Letters 2024年第9期41卷 57-62页

作者： Jingyu Yao Haohao Sheng Ruihan Zhang Rongtian Pang Jin-Jian Zhou Quansheng Wu Hongming Weng Xi Dai Zhong Fang Zhijun Wang Beijing National laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081China Department of Physics Hong Kong University of Science and TechnologyHong Kong 999077China

By systematic theoretical calculations,we reveal an excitonic insulator(EI)in the Ta_(2)Pd_(3)Te_(5)*** bulk Ta_(2)Pd_(3)Te_(5)is a van der Waals(vdW)layered compound,whereas the vdW layer can be obtained through exfoliation or molecular-beam ***-principles calculations show that the monolayer is a nearly zero-gap semiconductor with the modified Becke–Johnson *** to the same symmetry of the band-edge states,the two-dimensional polarization 2D would be finite as the band gap goes to zero,allowing for an EI state in the *** the first-principles many-body perturbation theory,the GW plus Bethe–Salpeter equation calculation reveals that the exciton binding energy is larger than the single-particle band gap,indicating the excitonic *** computed phonon spectrum suggests that the monolayer is dynamically stable without lattice *** findings suggest that the Ta_(2)Pd_(3)Te_(5) monolayer is an excitonic insulator without structural distortion.

关键词： monolayer principles calculations

Electrochemical reconstruction: a new perspective on Sn metal-organic complex microbelts as robust anode for lithium storage

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Rare Metals 2024年第1期43卷 76-86页

作者： Jin-Ke Shen Nai-Teng Wu Li-Yuan Wang Gang Jiang Dong-Lei Guo Jin Li Gui-Long Liu Hong-Yu Mi Huan Pang Xian-Ming Liu Key laboratory of Function-oriented Porous Materials of Henan Province College of Chemistry and Chemical EngineeringLuoyang Normal UniversityLuoyang 471934China State Key laboratory of Chemistry and Utilization of Carbon Based Energy Resources School of Chemical Engineering and TechnologyXinjiang UniversityUrumqi 830046China School of Chemistry and Chemical Engineering Institute for Innovative Materials and EnergyYangzhou UniversityYangzhou 225009JiangsuChina

Tin-based materials with high theoretical capacity and suitable working voltage are ideal anode materials for lithium-ion batteries(LIBs). However, to overcome their shortcomings(volume expansion and inferior stability), the preparation processes are usually complicated and expensive. Herein, a tin-based metal-organic complex(tin 1,2-benzenedicarboxylic acid, Sn-BDC)with one-dimensional microbelt morphology is synthesized by a facile, rapid and low-cost co-precipitation method, and served as anode material for LIBs without any post-treatment. Sn-BDC exhibits a high reversible capacity with609/440 m Ah·g^(-1) at 50/2000 m A·g^(-1), and robust cycling stability of 856 m Ah·g^(-1) after 200 cycles at 200 m A·g^(-1),which are obviously superior to that of the Sn Ox/C counterparts. Moreover, an electrochemical reconstruction perspective on the lithium storage mechanism of Sn-BDC is proposed by systematic ex-situ characterizations. The reconstructed SnO_(2) replaces Sn-BDC and becomes the active material in the subsequent cycles. As the by-product of the lithiation reaction, the formed Li-based metal-organic complex(Li-BDC, wrapped around the reconstructed SnO_(2)) plays an important role in alleviating volume expansion and accelerating the charge transfer *** work is beneficial to design and construct the new electrode materials based on the electrochemical reconstruction for advanced LIBs.

关键词： Electrochemical reconstruction Metal-organic complex Anode Lithium storage mechanism Lithium-ion batteries

Thioacetamide Additive Homogenizing Zn Deposition Revealed by In Situ Digital Holography for Advanced Zn Ion Batteries

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Nano-Micro Letters 2024年第6期16卷 261-275页

作者： Kaixin Ren Min Li Qinghong Wang Baohua Liu Chuang Sun Boyu Yuan Chao Lai Lifang Jiao Chao Wang School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou 221116JiangsuPeople’s Republic of China Jiangsu Key laboratory of Advanced Laser Materials and Devices School ofPhysics and Electronic EngineeringJiangsu Normal UniversityXuzhou 221116JiangsuPeople’s Republic of China Key laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai University300071 TianjinPeople’s Republic of China

Zinc ion batteries are considered as potential energy storage devices due to their advantages of low-cost,high-safety,and high theoretical ***,dendrite growth and chemical corrosion occurring on Zn anode limit their *** problems can be tackled through the optimization of the ***,the screening of electrolyte additives using normal electrochemical methods is time-consuming and ***,a fast and simple method based on the digital holography is *** can realize the in situ monitoring of electrode/electrolyte interface and provide direct information concerning ion concentration evolution of the diffusion *** is effective and time-saving in estimating the homogeneity of the deposition layer and predicting the tendency of dendrite growth,thus able to value the applicability of electrolyte *** feasibility of this method is further validated by the forecast and evaluation of thioacetamide *** on systematic characterization,it is proved that the introduction of thioacetamide can not only regulate the interficial ion flux to induce dendrite-free Zn deposition,but also construct adsorption molecule layers to inhibit side reactions of Zn *** easy to operate,capable of in situ observation,and able to endure harsh conditions,digital holography method will be a promising approach for the interfacial investigation of other battery systems.

关键词： Digital holographic microscopy In situ observation Electrode/electrolyte interface Zn dendrites Screening electrolyte additives