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Effect of surfactant frequently used in soil flushing on oxygen mass transfer in micro-nano-bubble aeration system

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Chinese Journal of Chemical Engineering 2024年第3期67卷 174-181页

作者： Mei Bai Zhibin Liu Zhu Liu Chenfei He Zhanhuang Fan Miaoxin Yuan Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety Southeast UniversityNanjing 211189China CECEP DADI(Hangzhou)Environmental Remediation Co. Ltd.Hangzhou 310020China

In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated *** surfactant present in flushing solutions is bound to affect the aeration *** purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MNB)aeration ***,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MNB aeration ***,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MNB *** results showed that,for the twenty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)*** phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant *** addition,with the presence of electric charge,MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant ***,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant ***,the modified Frossling's model predicted the effect of surfactant on kL in MNB aeration system with reasonable accuracy.

关键词： Soil flushing Micro-nano-bubble aeration Bio-surfactant Mass transfer coefficient

Fast internal preheating of 4680 lithium-ion batteries in cold environments

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Nano research 2024年第10期17卷 8794-8802页

作者： Chuyue Guan Harrison Szeto Olivia Wander Vijay Kumar Raphaele JClément Yangying Zhu Department of Mechanical Engineering University of California Santa BarbaraSanta BarbaraCA 93106USA Department of Chemistry and Biochemistry University of California Santa BarbaraSanta BarbaraCA 93106USA Department of Materials University of California Santa BarbaraSanta BarbaraCA 93106USA

Lithium-ion batteries are expected to operate within a narrow temperature window around room temperature for optimal performance and ***,in cold environments,electric vehicle battery packs must be extensively preheated prior to charge or ***,conventional preheating is accomplished externally,which is slow and thus significantly increases charging ***,internal heating has been demonstrated as a potential solution to quickly and uniformly preheat a lithium-ion pouch ***,internal heating has not been evaluated in other battery formats such as cylindrical *** this work,we present a numerical model of a 4680 battery with internal heaters for fast preheating in cold *** effects that the number of heater layers,heating duration,resting duration,environmental temperature,and boundary heat transfer coefficient have on the temperature heterogeneity of the battery were *** results show that internal heating alone reduces the temperature variation within the battery by a factor of 5 compared to external heating,and by a factor of 20 when combining internal and external *** study further proves that internal preheating of lithium-ion batteries is a promising thermal management strategy,and provides guidance on potential design considerations and heating protocols to implement internal heating.

关键词： lithium-ion battery 4680 battery thermal management internal battery preheating COMSOL Multiphysics thermal simulation battery temperature heterogeneity

Nonexistence of quantum black and white hole horizons in an improved dynamic approach

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science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 56-73页

作者： Wen-Cong Gan Xiao-Mei Kuang Zhen-Hao Yang Yungui Gong Anzhong Wang Bin Wang College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China GCAP-CASPER Physics DepartmentBaylor UniversityWaco 76798-7316USA Institute for Theoretical Physics&Cosmology Zhejiang University of TechnologyHangzhou 310023China United Center for Gravitational Wave Physics(UCGWP) Zhejiang University of TechnologyHangzhou 310023China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Department of Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

In this paper,we study the quantum geometric effects near the locations where classical black hole horizons used to appear in Einstein's classical theory,within the framework of an improved dynamic approach,in which the internal region of a black hole is modeled by the Kantowski-Sachs(KS)spacetime and the two polymerization parameters are functions of the phase space *** detailed analysis shows that the effects are so strong that black and white hole horizons of the effective quantum theory do not exist at all and instead are replaced by transition surfaces,across which the metric coefficients and their inverses are smooth and remain finite,as are the corresponding curvatures,including the Kretschmann *** surfaces always separate trapped regions from anti-trapped *** number of such surfaces is infinite,so the corresponding KS spacetimes become geodesically complete,and no black and white hole-like structures exist in this scheme.

关键词： canonical quantization loop quantum gravity quantum aspects of black holes

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Cobalt-doped TiO_(2)@C hierarchical nanocomposites derived from Ti_(3)C_(2) MXene as cathodes for hybrid magnesium-lithium batteries

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Nano research 2024年第1期17卷 253-261页

作者： Xiaohui Li Yakun Tang Lang Liu Yue Zhang Yang Gao Mao Qian Wenjie Ma State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830017China

TiO_(2)has been explored in hybrid magnesium-lithium batteries(HMLBs)due to the advantages of low self-discharge and small volume expansion during ion ***,how to improve the inherently low ionic and electrical conductivity of TiO_(2)is the problem that needs to be *** this work,a smart strategy is adopted to prepare cobalt-doped TiO_(2)@C(Co^(4+)-TiO_(2)@C)hierarchical nanocomposite derived from Co(II)(OH)n@*** with TiO_(2)@C(without cobalt doping),Co^(4+)-TiO_(2)@C shows the highest specific capacity(154.7 mAh·g^(-1)at 0.1 A·g^(-1)after 200 cycles)and extraordinary rate performance in *** excellent electrochemical performance of Co4+-TiO_(2)@C is ascribed to the synergistic effect of the hierarchical structure and *** experimental results and density functional theory(DFT)calculation reveal that the cobalt-doping has effectively improved the electronic conductivity and reduced the Li+migration *** work provides a new insight to design TiO_(2)-based cathode materials with high-performance in HMLBs.

关键词： Ti_(3)C_(2)MXene TiO_(2) hybrid magnesium-lithium batteries hierarchical structure cobalt-doping

An improved elastoplastic model for rocks and application to cyclic loading and unloading triaxial compression tests

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Acta Mechanica Sinica 2024年第8期40卷 179-193页

作者： Qiuxin Gu Qiang Zhang Yapeng Li Peinan Wu Guilei Han State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou221116China North China Engineering Investigation Institute Shijiazhuang050021China

The recoverable strain of rock is completely classified as elastic strain in the conventional elastic-plastic theory,which often results in poor agreement between theoretical and experimental *** work proposes an improved elastoplastic model of rock materials considering the evolutions of crack deformation and elastic modulus to better characterize the nonlinear mechanical behavior of rock in the post-peak *** this model,the recoverable strain is assumed to be a combination of elastic and crack strain,and the constitutive relationship between crack strain and rock stress is *** on the proposed assumption,the evolutions of the mechanical parameters including strength parameters,elastic,plastic,and crack deformation parameters versus the plastic strain and confining stress were *** developed elastoplastic model was validated by comparing the theoretical values with the results of the triaxial cyclic loading and unloading *** theoretical calculation results show a good agreement with the laboratory test,which indicates that the improved elastoplastic model can effectively reflect the nonlinear mechanical behavior of the rock *** research results are expected to provide a valuable reference for further understanding the evolution of rock crack deformation.

关键词： Crack strain Elastic modulus deterioration Novel elastoplastic model Model validation

Synthetic fungal melanin UV absorbers

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science China Chemistry 2024年第9期67卷 3098-3110页

作者： Chao Wang Rong Zhang Jianhua Zhang Xueqian Zhang Hengjie Zhang Huan Cao Zhen Yang Yiwen Li College of Polymer science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Department of Radiology Huaxi MR Research CenterFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceNational Clinical Research Center for GeriatricsWest China HospitalSichuan UniversityChengdu 610041China

Agents with robust ultraviolet(UV)absorption capabilities play a vital role in safeguarding organisms and inorganic materials from UV ***,the synthetic procedures towards these UV absorbers are usually lengthy and complicated,accompanied by undesirable side reactions and the generation of toxic *** nature,allomelanin,a class of melanins variant found in melanized fungi near the Chernobyl nuclear power plant,plays crucial roles in the cell wall of melanized fungi,offering resistance to harsh external environments and promising UV resistance ***,allomelanin can be rapidly biosynthesized via the polymerization of 1,8-dihydroxynaphthalene in presence of enzymes in *** by this,we report here a green enzymatic polymerization strategy to efficiently and eco-friendly synthesize polydihydroxynaphthalene(PDHN)-based artificial allomelanin nanoparticles(NPs)with interesting *** calculations and experimental results demonstrated that the PDHN NPs exhibited excellent UVabsorption capacity,surpassing another widely used artificial melanin,polydopamine(PDA).Moreover,the light absorption mechanism of PDHN NPs was systematically elucidated for the first ***,the PDHN NPs were incorporated with polyvinyl alcohol(PVA)to create an anti-aging composite film with significantly enhanced UV shielding *** potential of these composite films in safeguarding plants from UV damage was meticulously ***,these PDHN NPs were first found to produce hydroxyl radicals(·OH)under UV irradiation,offering antibacterial properties that expand their potential applications.

关键词： melanin artificial allomelanin nanoparticles green synthesis UV absorption antibacterial

Symmetry quantification and segmentation in STEM imaging through Zernike moments

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Chinese Physics B 2024年第8期33卷 39-48页

作者： Jiadong Dan Cheng Zhang 赵晓续 N.Duane Loh Department of Biological sciences National University of SingaporeSingapore Center for Bioimaging sciences(CBIS) National University of SingaporeSingapore Department of Physics National University of SingaporeSingapore School of Materials science and Engineering Peking UniversityBeijing 100871China

We present a method using Zernike moments for quantifying rotational and reflectional symmetries in scanning transmission electron microscopy(STEM)images,aimed at improving structural analysis of materials at the atomic *** technique is effective against common imaging noises and is potentially suited for low-dose imaging and identifying quantum *** showcase its utility in the unsupervised segmentation of polytypes in a twisted bilayer TaS_(2),enabling accurate differentiation of structural phases and monitoring transitions caused by electron beam *** approach enhances the analysis of structural variations in crystalline materials,marking a notable advancement in the characterization of structures in materials science.

关键词： scanning transmission electron microscopy(STEM) symmetry segmentation

Lifetime-tunable circularly polarized luminescent system based on triplet-to-singlet Förster resonance energy transfer

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science China Chemistry 2024年第9期67卷 2918-2922页

作者： Zhenyi He Zizhao Huang Xiang Ma Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint research Center Institute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Circularly polarized luminescence(CPL)materials have received widespread attention due to their remarkable performance and broad ***,current CPL material research primarily focuses on tunable color,intensity,and *** CPL with adjustable lifetime remains a significant ***,a series of CPL polymeric materials with tunable lifetime were obtained by employing phosphorescent terephthalic acid and chiral organic small molecule R/S-BNAF(a luminescent binaphthol derivative)to copolymerize with acrylamide in different *** was verified that this performance results from the different energy transfer efficiency between luminophores with varying ratios of the monomers for *** strategy to realize CPL with tunable lifetime by modulating the energy transfer efficiency will provide a new perspective to broaden the applications of CPL materials.

关键词： circularly polarized luminescence tunable lifetime Förster resonance energy transfer room temperature phosphorescence

Batch Active Learning for Multispectral and Hyperspectral Image Segmentation Using Similarity Graphs

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1013-1033页

作者： Bohan Chen Kevin Miller Andrea L.Bertozzi Jon Schwenk Department of Mathematics University of CaliforniaLos Angeles520 Portola PlazaLosAngeles90095CAUSA Oden Institute for Computational Engineering and sciences University of Texas at Austin201 E 24th StAustin 78712TXUSA Los Alamos national Laboratory Los AlamosNM 87545USA

Graph learning,when used as a semi-supervised learning(SSL)method,performs well for classification tasks with a low label *** provide a graph-based batch active learning pipeline for pixel/patch neighborhood multi-or hyperspectral image *** batch active learning approach selects a collection of unlabeled pixels that satisfy a graph local maximum constraint for the active learning acquisition function that determines the relative importance of each pixel to the *** work builds on recent advances in the design of novel active learning acquisition functions(e.g.,the Model Change approach in arXiv:2110.07739)while adding important further developments including patch-neighborhood image analysis and batch active learning methods to further increase the accuracy and greatly increase the computational efficiency of these *** addition to improvements in the accuracy,our approach can greatly reduce the number of labeled pixels needed to achieve the same level of the accuracy based on randomly selected labeled pixels.

关键词： Image segmentation Graph learning Batch active learning Hyperspectral image