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confinement of Fe atoms between MoS_(2) interlayers drives phase transition for improved reactivity in Fenton-like reactions

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Nano Research 2024年第3期17卷 1132-1139页

作者： Yibing Sun Yu Zhou Hongchao Li Chuan Wang Xuan Zhang Qian Ma Yingchun Cheng Jieshu Qian Bingcai Pan Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Flexible Electronics and Institute of Advanced Materials Jiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 211816China Department of General Dentistry Affiliated Stomatological Hospital of Nanjing Medical UniversityJiangsu Province Key Laboratory of Oral DiseasesNanjing 210029China Research Center for Environmental Nanotechnology(ReCENT) State Key Laboratory of Pollution Control and Resources ReuseSchool of EnvironmentNanjing UniversityNanjing 210023China

Phase manipulation of MoS_(2) from thermodynamically stable 2H phase to the unstable but more reactive 1T phase represents a crucial strategy for improving the reactivity in many reactions.The widely adopted wet chemistry approach uses intercalating entities especially alkali metal ions to achieve the phase transition;however,these entities are normally inert for the target reaction.Here,we describe the first use of iron atoms for the intercalation of 2H-MoS_(2) layers,driving the partial transition from 2H to 1T phase.Interestingly,in the peroxymonosulfate(PMS)-based Fenton-like reactions,the interlayered confinement of Fe atoms not only activates the inert basal plane,but also adds more reactive Fe sites for the formation of metal-PMS complex as primary reactive species for pollutant removal.In the degradation of a model pollutant carbamazepine(CBZ),the Fe-intercalated MoS_(2) exhibits a first order rate constant 13.3 times higher than 2H-MoS_(2).This strategy is a new direction for manipulating the phase composition and boosting the catalytic reactivity of MoS_(2)-based catalysts in various scenarios,including environmental remediation and energy applications.

关键词： confinement MoS_(2) Fe atoms Fenton-like reactions hydrogen evolution reaction

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Reversible isomerization of donor-acceptor Stenhouse adduct derivatives in water through dendritic confinement

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Science China Chemistry 2024年第5期67卷 1636-1646页

作者： Jiaxing Zhang Qingyun Zhao Xinyan Su Afang Zhang Wen Li International Joint Laboratory of Biomimetic and Smart Polymers School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

Modulating reversible isomerization of hydrophobic dyes in aqueous solutions is greatly desired. Here we report on reversible isomerization of solvatochromic donor-acceptor Stenhouse adducts(DASAs) in water through the confinement from dendritic oligoethylene glycols(OEGs). Dendronization of DASAs with dendritic OEGs affords them characteristic thermoresponsiveness. These dendronized DASAs spontaneously isomerize in water from hydrophobic linear state into hydrophilic cyclic state at room temperature due to the strong hydration. However, hydrophobic microenvironment through thermally dehydration and collapse of the dendritic OEGs at elevated temperatures confines hydration of the DASA moieties and mediates their interactions with the collapsed hydrophobic OEG domains, affording their isomerization recovery in water efficiently from the hydrophilic cyclic state into the hydrophobic linear state. The confinement-mediated reversible isomerization of DASA moieties in water can be repeated through alternative photo-irradiation and thermal dehydrations, exhibiting excellent fatigue resistance.

关键词： dendrimers donor-acceptor Stenhouse adducts isomerization confinement thermoresponsiveness

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Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony R.J.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOR).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox reaction.Characterizations via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the Pt.The electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the electrocatalyst.The single-atom samples showed higher HOR activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating range.The selective activity toward HOR arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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Strong shock propagation for the finite-source circular blast in a confined domain

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1071-1084页

作者： Qihang MA Kaileong CHONG Bofu WANG Quan ZHOU Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Shanghai Institute of Aircraft Mechanics and Control Shanghai 200092China

The circular explosion wave produced by the abrupt discharge of gas from a high-temperature heat source serves as a crucial model for addressing explosion phenomena in compressible flow.The reflection of the primary shock and its propagation within a confined domain are studied both theoretically and numerically in this research.Under the assumption of strong shock,the scaling law governing propagation of the main shock is proposed.The dimensionless frequency of reflected shock propagation is associated with the confined distance.The numerical simulation for the circular explosion problem in a confined domain is performed for validation.Under the influence of confinement,the principal shock wave systematically undergoes reflection within the domain until it weakens,leading to the non-monotonic attenuation of kinetic energy in the explosion fireball and periodic oscillations of the fireball volume with a certain frequency.The simulation results indicate that the frequency of kinetic energy attenuation and the volume oscillation of the explosive fireball align consistently with the scaling law.

关键词： explosion confinement main shock frequency

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Nonlinear Study on the Mechanical Performance of Built-Up Cold-Formed Steel Concrete-Filled Columns under Compression

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3435-3465页

作者： Oulfa Harrat Yazid Hadidane S.M.Anas Nadhim Hamah Sor Ahmed Farouk Deifalla Paul O.Awoyera Nadia Gouider Civil Engineering Laboratory Faculty of TechnologyDepartment of Civil EngineeringBadji Mokhtar-Annaba UniversityP.O.Box 12Annaba23000Algeria Department of Civil Engineering Faculty of Engineering and TechnologyJamia Millia Islamia(A Central University)New Delhi110025India Civil Engineering Department University of GarmianKalar46021Iraq Department of Civil Engineering Harran UniversitySanliurfa63510Turkey Structural Engineering and Construction Management Department Future University in EgyptNew Cairo11835Egypt Department of Civil Engineering Covenant UniversityOta112233Nigeria

Given their numerous functional and architectural benefits,such as improved bearing capacity and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up sections have become increasingly developed and used in recent years,particularly in the construction industry.This paper presents an analytical and numerical study of assembled CFS two single channel-shaped columns with different slenderness and configurations(backto-back,face-to-face,and box).These columns were joined by double-row rivets for the back-to-back and box configurations,whereas they were welded together for the face-to-face design.The built-up columns were filled with ordinary concrete of good strength.Finite element models were applied,using ABAQUS software,to assess mechanical performance and study the influence of assembly techniques on the behavior of cold-formed columns under axial compression.Analytical approaches based on Eurocode 3 and Eurocode 4 recommendations for un-filled and concrete-filled columns respectively were followed for the numerical analysis,and concrete confinement effects were also considered per American Concrete Institute(ACI)standards for face-to-face and box configurations.The obtained results indicated a good correlation between the numerical results and the proposed analytical methodology which did not exceed 8%.The failure modes showed that the columns failed due to instabilities such as local and global buckling.

关键词： Cold-formed steel built-up sections slenderness rivets welded axial compression analytical approaches confinement buckling

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Recent applications of macrocycles in supramolecular catalysis

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Chinese Chemical Letters 2024年第4期35卷 132-141页

作者： Conghui Wang Lei Xu Zhenhua Jia Teck-Peng Loh College of Advanced Interdisciplinary Science and Technology Henan University of TechnologyZhengzhou 450001China Division of Chemistry and Biological Chemistry School of Chemistry Chemical Engineeringand BiotechnologyNanyang Technological UniversitySingapore 637371Singapore Institute of Advanced Synthesis School of Chemistry and Molecular Engineering Nanjing Tech UniversityNanjing 211816China

Numerous supramolecular macrocycles have been utilized for developing catalysts by exploiting their specific molecular recognition and ability to form inclusion complexes through noncovalent interactions. The cyclic structure and modified functional groups of these macrocycles can influence substrate and transition state stability, as well as reaction selectivity. The inner cavities of these macrocycles are particularly beneficial, as they enable substrates to adopt preorganized arrangements and serve as versatile platforms for highly efficient supramolecular catalytic systems. This minireview provides an overview of recent advancements in supramolecular catalysis using various macrocycles, such as crown ethers, cyclodextrins,calixarenes, pillararenes, cucurbiturils, and other novel macrocycles.

关键词： Supramolecular catalysis Macrocycle Host-guest interactions confinement Selectivity

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Hydrogen-incorporated vanadium dioxide nanosheets enable efficient uranium confinement and photoreduction

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Nano Research 2022年第4期15卷 2943-2951页

作者： Huanhuan Liu Jia Lei Jiali Chen Ye Li Changyao Gong Shangjie Yang Yamin Zheng Ning Lu Yan Liu Wenkun Zhu Rong He State Key Laboratory of Environment-friendly Energy Materials National Co-innovation Center for Nuclear Waste Disposal and Environmental SafetySichuan Civil-military Integration InstituteSouthwest University of Science and TechnologyMianyang 621010China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China

Photocatalytic reduction of U(VI)represents a novel and effective manner for the removal of U(VI)pollutant from radioactive wastewater.Herein,we successfully incorporated hydrogen into VO_(2)nanosheets,which strengthened the interaction between VO_(2)and U(VI),thereby achieving a highly active and stable photocatalyst for U(VI)reduction.With the increase of H content in hydric VO_(2)(H_(x)-VO_(2))nanosheets,the bandgap shrank from 2.29 to 1.66 eV,whereas the position of conduction bands remained more negative than the reduction potential of U(VI)/U(IV)(0.41 V vs.NHE).When irradiated by simulated sunlight,the U(VI)removal efficiency over H0.613-VO_(2)nanosheets reached up to 95.4%within 90 min,which largely outperformed 28.3%of pristine VO_(2)nanosheets.The mechanistic study demonstrated that the hydroxylated surface gave rise to the balanced O confinement sites in VO_(2)(011),leading to the stabilized adsorption configuration and increased binding strength of UO_(2)^(2+)on H_(x)-VO_(2)nanosheets.

关键词： VO_(2)nanosheets hydroxylated surface confinement photoreduction uranium

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Novel confinement combustion method of nanosized WC/C for efficient electrocatalytic oxygen reduction

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International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1627-1634页

作者： Pengqi Chen Yunxiao Tai Huan Wu Yufei Gao Jiayu Chen Jigui Cheng School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology Hefei University of TechnologyHefei 230009China AECC Commercial Aircraft Engine Co. Ltd.Shanghai 200241China Research Centre for Powder Metallurgy Engineering and Technology of Anhui Province Hefei 230009China

Nanosized tungsten carbide(WC)/carbon(C)catalyst was synthesized via a novel ultra-rapid confinement combustion synthesis method.The amount of activated carbon(AC)plays an important role in the morphology and structure,controlling both the precursor and final powder.The WC particles synthesized inside the pores of the AC had been 10-20 nm because of the confinement of the pore structure and the large specific surface area of AC.When used for oxygen reduction performance,the half-wave potential was−0.24 V,and the electron transfer number was 3.45,indicating the main reaction process was the transfer of four electrons.The detailed electrocatalytic performance and underlying mechanism were investigated in this work.Our study provides a novel approach for the design of catalysts with new compositions and new structures,which are significant for promoting the commercialization of fuel cells.

关键词： confinement combustion synthesis tungsten carbide activated carbon electrochemical catalysis oxygen reduction reaction

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In-situ monitoring of cell-secreted lactate by electrochemiluminescence sensing under biomimetic microfluidic confinement

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Chinese Chemical Letters 2022年第5期33卷 2705-2707页

作者： Yixin Liu Yuanyuan Yao Beibei Yang Yan-Jun Liu Baohong Liu Department of Chemistry Shanghai Stomatological Hospitaland State Key Lab of Molecular Engineering of PolymersFudan UniversityShanghai 200433China Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism(Ministry of Science and Technology)Institutes of Biomedical SciencesFudan UniversityShanghai 200032China College of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing 314001China Department of Chemistry and Chemical Engineering Nantong UniversityNantong 226000China

Cell migration proceeds in 3D matrices in vivo,which can naturally switch to distinct phenotypes for bet-ter invasion in confined microenvironments.The studies of important metabolites under confinement are extremely meaningful for comprehensive insights into cancer metastasis.The integration of cell confine-ment device and analytical techniques is a key point for in-situ analysis of significant metabolites in vitro.Herein,an electrochemiluminescence(ECL)sensing platform was designed for in-situ monitoring of cell-secreted lactate in highly confined microenvironments.The 3-μm confiner was exactly fabricated via mi-crofabrication and microfluidics technique,and cells in high confinement and low adhesion tended to be round with contractile blebs on cell margins.Significantly,in-situ monitoring of lactate was successfully achieved on the ECL platform with the catalysis of lactate oxidase,in which the levels in different time intervals were acquired in the luminol-hydrogen peroxide system.Furthermore,the results were verified by the liquid chromatography-tandem mass spectrometry(LC-MS/MS)technology,which showed similar fluctuations with the ECL platform.This system offered an available avenue for metabolites analysis in highly confined microenvironments,which may advance deeper insights into metabolic mechanisms of cancer metastasis.

关键词： confinement ECL sensing platform In-situ monitoring

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Unification of Gravitational and Strong Interaction Fields Using Partial Gauge Symmetry

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第2期10卷 515-533页

作者： Young Hwan Yun Kiho Jang Zero Theoretical Physics Lab Seoul Republic of Korea

We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms like the well-type potential where a particle behaves almost freely but is very hard to escape without external energy, which can be interpreted as local confinement and asymptotic freedom. By assuming a 2-dimensional metric tensor in 4-dimensional space-time, we suggest the existence of 3 kinds of particles that resemble QCD with 3 color charges. We also show that the mass term exists but comes to zero and derive the charge and spin values. We can regard the particle with this new potential as a gluon, and the interaction in this well-type potential as a strong interaction for the properties of mass, charge, spin, and its behavior. We suggest the eight-fold way with this new particle, which is similar to the existing method based on SU (3) symmetry. Even though the strong interaction has been analyzed in the standard model and string theory, we build a new consistent model based on the theory of relativity including Riemann geometry, and show the unification of gravitational and strong interactional field.

关键词： Strong Interaction Gauge Symmetry Relativity QCD confinement Asymptotic Freedom

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