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Chinese Journal of Chemical Engineering 2024年第3期67卷 195-205页

作者： Chuanjun Di Jipeng Dong Fei Gao Guanghui Chen pan zhang Jianlong Li Key Laboratory of Multiphase Flow Reaction and Separation Engineering of Shandong Province College of Chemical EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Electromechanical Engineering Qingdao University of Science and TechnologyQingdao 266043China

It is of vital significance to investigate mass transfer enhancements for chemical engineering *** work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble *** image velocimetry(PIV)technology was employed to analyze the flow field and bubble motion behavior,and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient(kLa).The effect of embedding wire mesh,adding solid particles,and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and *** results show that the gas-liquid interface area increases by 33%-72%when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow,which is superior to the other two strengthening *** with the system without reinforcement,kLa in the bubble column increased by 0.5-1.8 times with wire mesh coupling solid particles method,which is higher than the sum of kLa increases with inserting wire mesh and adding particles,and the coupling reinforcement mechanism for affecting gas-liquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer.

关键词： Fluid mechanics Bubble Mass transfer Wire mesh coupling solid particles Particle image velocimetry Hydrodynamics

Parametric investigation of railway fastenings into the formation and mitigation of short pitch corrugation

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Railway Engineering Science 2024年第3期32卷 286-306页

作者： pan zhang Shaoguang Li Rolf Dollevoet Zili Li Section of Railway Engineering Delft University of TechnologyStevinweg 12628 CN Delftthe Netherlands

Short pitch corrugation has been a problem for railways worldwide over one *** this paper,a parametric investigation of fastenings is conducted to understand the corrugation formation mechanism and gain insights into corrugation mitigation.A three-dimensional finite element vehicle-track dynamic interaction model is employed,which considers the coupling between the structural dynamics and the contact mechanics,while the damage mechanism is assumed to be differential *** fastening models with different configurations,boundary conditions,and parameters of stiffness and damping are built up and *** models may represent different service stages of fastenings in the ***,the effect of train speeds on corrugation features is *** results indicate:(1)Fastening parameters and modelling play an important role in corrugation formation.(2)The fastening longitudinal constraint to the rail is the major factor that determines the corrugation *** fastening vertical and lateral constraints influence corrugation features in terms of spatial distribution and wavelength components.(3)The strengthening of fastening constraints in the longitudinal dimension helps to mitigate ***,the inner fastening constraint in the lateral direction is necessary for corrugation alleviation.(4)The increase in fastening longitudinal stiffness and damping can reduce the vibration amplitudes of longitudinal compression modes and thus reduce the track corrugation *** simulation in this work can well explain the field corrugation in terms of the occurrence possibility and major wavelength *** can also explain the field data with respect to the small variation between the corrugation wavelength and train speed,which is caused by frequency selection and jump between rail longitudinal compression modes.

关键词： Short pitch corrugation Fastening modelling and parameters Corrugation formation and mitigation Rail longitudinal compression modes Finite element vehicle-track interaction model

Functional Group Effects for Photothermal Mass-energy Transfer in CO_(2) Capture and Conversion

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Chemical Research in Chinese Universities 2024年第3期40卷 451-461页

作者： ZENG Bingyuan XIA Tingting SUN Yanli zhang pan WANG Wenjing ZHAO Kun Hebei Key Lab of Power Plant Flue Gas Multi-pollutants Control Department of Environmental Science and EngineeringNorth China Electric Power UniversityBaoding 071003P.R.China School of Life Sciences Institute of Life Sciences and Green DevelopmentHebei UniversityBaoding 071002P.R.China

The surface microstructure can be influenced by surface environment,weak adsorption,and bonding interactions,leading to the changes of surface electronic states and the configuration of active sites,which affects the mass-energy transfer *** interaction between multiple species on the surface of light-absorbing materials directly impacts the performance of photothermal catalytic *** on this,we present the latest perspectives on photothermal CO_(2) capture and conversion,which focus on(1)the mechanism of functional group-assisted photothermal process,(2)the effects of functional group species,configurations,spatial positions,and surface interactions on photothermal catalytic reactions,and(3)the interaction between substrates and functional ***,an insightful perspective is drawn in the last section.

关键词： Molecular structure Photothermal effect Massenergytransfer CO_(2)captureand conversion

An intermittent lithium deposition model based on bimetallic MOFs derivatives for dendrite-free lithium anode with ultrahigh areal capacity

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Chinese Chemical Letters 2024年第8期35卷 520-525页

作者： Tao Wei Jiahao Lu pan zhang Qi zhang Guang Yang Ruizhi Yang Daifen Chen Qian Wang Yongfu Tang School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China State Key Laboratory of Metastable Materials Science and Technology(MMST) Hebei Key Laboratory of Applied ChemistryYanshan UniversityQinhuangdao 066004China College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China College of Energy Soochow UniversitySuzhou 215006China School of Low-carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou 221116China

In the development of 3D conductive frameworks for lithium metal anode(LMA),two models have been proposed:top growth model and bottom-up growth ***,Li tends to accumulate on the top of these 3D frameworks with homogenous lithiophilicity(top growth)and Li dendrite still *** address this issue,some researchers have focused on developing 3D frameworks with gradient lithio-philicity,which realized bottom-up growth of ***,partial Li nucleation sites on the top of these frameworks were *** by the two models talked above,this work firstly proposed a novel intermittent lithiophilic model for lithium *** demonstrate the feasibility of this model,a bimetallic metal-organic frameworks derived ZnMn_(2)O_(4)-MnO nanoparticles were grown on carbon cloth for *** can cycle stably under ultra-high current and areal capacity(10 mA/cm^(2),10 mAh/cm^(2)).The in-situ optical microscopy(OM)was conducted to observe the Li deposition behavior,no dendrite was found during 80 h in ester-based electrolyte while the pure Li only cycled for *** is more,it can also be well-coupled with LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode and solid-state electrolyte,which further prove the advantages of the intermittent model for the development of LMAs with high safety and high energy density.

关键词： Intermittent lithiophilic model Lithium metal anode(LMA) Three-dimensional(3D)frameworks Lithiophilic Bimetallic metal-organic frameworks(MOFs)

Cofitness network connectivity determines a fuzzy essential zone in open bacterial pangenome

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mLife 2024年第2期3卷 277-290页

作者： pan zhang Biliang zhang Yuan-Yuan Ji Jian Jiao Ziding zhang Chang-Fu Tian State Key Laboratory of Plant Environmental Resilience and College of Biological SciencesChina Agricultural UniversityBeijingChina MOA Key Laboratory of Soil Microbiology and Rhizobium Research CenterChina Agricultural UniversityBeijingChina Shenzhen Institute of Synthetic Biology Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina State Key Laboratory of Livestock and Poultry Biotechnology Breeding and College of Biological SciencesChina Agricultural UniversityBeijingChina

Most in silico evolutionary studies commonly assumed that core genes are essential for cellular function,while accessory genes are dispensable,particularly in nutrient-rich ***,this assumption is seldom tested genetically within the pangenome *** this study,we conducted a robust pangenomic Tn-seq analysis of fitness genes in a nutrient-rich medium for Sinorhizobium strains with a canonical open *** evaluate the robustness of fitness category assignment,Tn-seq data for three independent mutant libraries per strain were analyzed by three methods,which indicates that the Hidden Markov Model(HMM)-based method is most robust to variations between mutant libraries and not sensitive to data size,outperforming the Bayesian and Monte Carlo simulation-based ***,the HMM method was used to classify the fitness *** genes,categorized as essential(ES),advantage(GA),and disadvantage(GD)genes for growth,are enriched in core genes,while nonessential genes(NE)are over-represented in accessory *** ES/GA genes showed a lower fitness effect than core ES/GA *** degrees in the cofitness network decrease in the order of ES,GD,and GA/*** addition to accessory genes,1599 out of 3284 core genes display differential essentiality across test *** the pangenome core,both shared quasi-essential(ES and GA)and strain-dependent fitness genes are enriched in similar functional *** analysis demonstrates a considerable fuzzy essential zone determined by cofitness connectivity degrees in Sinorhizobium pangenome and highlights the power of the cofitness network in understanding the genetic basis of ever-increasing prokaryotic pangenome data.

关键词： cofitnessnetwork pangenome Tn-seq

At-rest lateral earth pressure of compacted expansive soils:Experimental investigations and prediction approach

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1425-1435页

作者： Zhong Han pan zhang Weilie Zou Kewei Fan Sai K.Vanapalli Lianglong Wan School of Civil Engineering Wuhan UniversityWuhanChina Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of the Ministry of Education Wuhan UniversityWuhanChina Department of Civil Engineering University of OttawaOttawaOntarioCanada Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjingChina Residence Engineering Management Station of Shenzhen Municipality ShenzhenChina

This paper presents experimental studies on a compacted expansive soil,from Nanyang,China for investigating the at-rest lateral earth pressureσL of expansive *** key studies include(i)relationships between theσL and the vertical stressσV during soaking and consolidation,(ii)the influences of initial dry densityρd0 and moisture content w 0 on the vertical and lateral swelling pressures at no swelling strain(i.e.σV0 andσL0),and(iii)evolution of theσL during five long-term wetting-drying *** results demonstrated that the post-soakingσL-σV relationships are piecewise linear and their slopes in the passive state(σL>σV)and active state(σLpansive soils available in the literature.

关键词： Lateral earth pressure Expansive soil Soaking Vertical stress Swelling pressure

Easy-to-perform organic-solvent-free synthesis of carbon dots with strong green photoluminescence

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Chinese Chemical Letters 2024年第3期35卷 373-378页

作者： Jiazhuang Guo Yifeng Chen pan zhang Ge Li Xiaoning Yang Cai-Feng Wang Su Chen State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

Carbon dots(CDs)have been extensively studied owing to their fascinating optical properties and wide potential ***,we report an easy-to-perform and organic-solvent-free synthesis strategy for green-emissive CDs(G-CDs)possessing high photoluminescence(PL)quantum yield(QY).The G-CDs are synthesized by heating the homogeneous precursors of citric acid and cyanamide in an open vessel,circumventing the use of organic solvents,complex operations,high-pressure reactors,and expensive instruments in the synthesis *** effect of various reaction variables on the formation and the optical properties of G-CDs are systematically *** resultant G-CDs show bright PL emission at 521 nm with PL QY up to 73%.Then a white light-emitting diode(LED)with Commission Internationable de L'Eclairage(CIE)coordinates of(0.33,0.34)and color rendering index(CRI)of 92 is constructed based on G-CDs/thermoplastic polyurethane(TPU)***,a visual microfluidic detection platform is designed by using G-CDs as fluorescent probes for rapid quantitative detection of Fe^(3+),Cu^(2+),and Mn^(2+)metal ions,which can realize synchronized testing of multiple *** study might promote the development and preparation methods of high-performance CDs with various optical applications.

关键词： Carbon dots Efficient synthesis Green fluorescence Quantum yield White LEDs Microfluidic detection platform

Research and design of matrix operation accelerator based on reconfigurable array

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High Technology Letters 2024年第2期30卷 128-137页

作者：邓军勇 zhang pan JIANG Lin XIE Xiaoyan DENG Jingwen School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121P.R.China School of Computer Science and Technology Xi’an University of Science and TechnologyXi’an 710054P.R.China School of Computer Xi’an University of Posts and TelecommunicationsXi’an 710121P.R.China

In the case of massive data,matrix operations are very computationally intensive,and the memory limitation in standalone mode leads to the system *** the same time,it is difficult for matrix operations to achieve flexible switching between different requirements when implemented in *** address this problem,this paper proposes a matrix operation accelerator based on reconfigurable arrays in the context of the application of recommender systems(RS).Based on the reconfigurable array processor(APR-16)with reconfiguration,a parallelized design of matrix operations on processing element(PE)array is realized with *** experimental results show that,compared with the proposed central processing unit(CPU)and graphics processing unit(GPU)hybrid implementation matrix multiplication framework,the energy efficiency ratio of the accelerator proposed in this paper is improved by about 35×.Compared with blocked alternating least squares(BALS),its the energy efficiency ratio has been accelerated by about 1×,and the switching of matrix factorization(MF)schemes suitable for different sparsity can be realized.

关键词： matrix factorization(MF) recommender system(RS) array processor reconfigurable matrix multiplication

Influence of temperature, stress, and grain size on behavior of nano-polycrystalline niobium

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Chinese Physics B 2024年第7期33卷 467-474页

作者：晏玉平张柳亭张丽攀芦刚涂志新 School of Acronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063China

Atomic simulations are executed to investigate the creep responses of nano-polycrystalline(NC) niobium established by using the Voronoi algorithm. The effects of varying temperature, applied stress, and grain size(GS) on creep properties and mechanisms are investigated. Notably, the occurrence of tertiary creep is exclusively observed under conditions where the applied stress exceeds 4.5 GPa and the temperature is higher than 1100 K. This phenomenon can be attributed to the significant acceleration of grain boundary and lattice diffusion, driven by the elevated temperature and stress levels. It is found that the strain rate increases with both temperature and stress increasing. However, an interesting trend is observed in which the strain rate decreases as the grain size increases. The stress and temperature are crucial parameters governing the creep behavior. As these factors intensify, the creep mechanism undergoes a sequential transformation: initially from lattice diffusion under low stress and temperature conditions to a mixed mode combining grain boundaries(GBs) and lattice diffusion at moderate stress and mid temperature levels, and ultimately leading to the failure of power-law controlled creep behavior, inclusive of grain boundary recrystallization under high stress and temperature conditions. This comprehensive analysis provides in more detail an understanding of the intricate creep behavior of nano-polycrystalline niobium and its dependence on various physical parameters.

关键词： creep behavior molecular dynamics simulation activation energy stress exponent nano-polycrystalline niobium

Primary and Secondary Calcite in Chinese Loess Distinguished by Crystallinity and Implications for Illuviation Depth and East Asian Summer Monsoon Intensity

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Journal of Earth Science 2024年

作者： Yan Zhao Kangjun Huang Yuanqiang Guo pan zhang Yawen Lu Long Ma State Key Laboratory of Continental Dynamics， Shaanxi Key Laboratory of Early Life and Environment， Department of Geology， Northwest University

The crystallinity has the potential to distinguish the primary and secondary calcite in Chinese loess， which then provides insights into illuviation depth and variations of the East Asian summer monsoon. However， this aspect has been rarely investigated. In this study， we defined the crystallinity of calcite as the Height/Area (H/A) ratio of the diffracted peak at crystal face (1 0 4). The H/A ratio inversely correlates with the average width of the diffracted peak， where a higher H/A ratio indicates higher crystallinity of calcite. Through the mixing and synthetic experiments， we found that the H/A ratio is minimally affected by factors such as calcite content， deposition temperature or rate but significantly influenced by the ionic impurity and the mixing proportion of different calcites. Subsequently， we examined desert samples of loess sources and loess carbonate nodules. Desert samples predominantly consist of primary calcite which inherits characteristics from cryptocrystalline limestone with high levels of ionic impurities resulting in low H/A ratio of 4.30 ± 0.51. In contrast， loess carbonate nodules contain abundant secondary calcite precipitated within soil interstices with low levels of ionic impurities leading to a significantly higher H/A ratio of 7.76 ± 0.82. Consequently， higher H/A ratios during interglacial periods compared to glacial periods are attributed to variations in relative proportions between primary and secondary calcite in loess sequences. The thickness， between the glacial-interglacial boundary and the depth where the H/A ratio starts to increase from the bottom to the top in the loess layer， can be used to indicate the illuviation depth of upper-soil carbonates and the intensity of the East Asian summer monsoon. This proxy can be further applied in long-term loess sequences to uncover the summer monsoon evolution.

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