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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

Can the late dark energy parameterization reconcile the Hubble tension?

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Chinese Physics C 2024年第7期48卷 244-252页

作者：张明建陈丽杨茂友王俊美 international school for Optoelectronic engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

In this study,we constructed ten dark energy models to test whether they can reconcile the Hubble tension and how much it is affected by *** establish a fair test,the models are diverse,encompassing fractional,logarithmic,exponential,and inverse exponential forms as well as several non-parameterized *** dataset we used includes the NPIPE pipeline of cosmic microwave background(CMB)power-spectrum data from Planck2020,Pantheon+samples from Supernovae Type la,and baryon acoustic *** MCMC calculations imply dark energy transferring from w-1 for the four parameterized dark energy ***,these models cannot adequately reconcile the Hubble ***,we found that phantom-like dark energy with w<-1 can achieve the greatest reduction in the Hubble tension to ***,AIC analysis indicates that this alleviation is at the cost of high *** also investigated the effect of constructions on the derivative of the equation of state dw/da,cosmic density parameter,CMB power spectrum C^(TT),and mater spectra P(k).We also found that the Hubble tension may be related to the reionization process.

关键词： dark energy Hubble tension CMB

Design of high frequency broadband low insertion loss SAW filter at 3.5 GHz

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 55-61页

作者： Wang Wei Zhang Ying Wang Fang Wu Hao Ding Hui Xia Xu Wang Guanyu Xie Yingtao school of Optoelectronics engineering/international Semiconductor College Chongqing University of Posts and TelecommunicationsChongqing 400065China

With the wide application of the fifth-generation mobile communication system(5G)technology,wireless communication equipment tends to develop in miniaturization,high frequency,and low *** this paper,a surface acoustic wave(SAW)filter with a center frequency of 3.5 GHz was ***,the acoustic waveguide structure of the longitudinal leaky SAW(LLSAW)excitation is determined,and the two-dimensional(2D)theoretical model of the device is established by COMSOL ***,the influence of electrode parameters on the performance of the device is studied,and the electrode parameters are optimized on this *** setting the device structure parameters reasonably,the spurious in the passband can be effectively ***,the center frequency of the mirror T-structure LLSAW filter is 3.536 GHz,the insertion loss is-1.414 dB,the bandwidth of-3 dB is 276 MHz,and the out-of-band rejection is greater than-30 dB.

关键词： surface acoustic wave(SAW) electrode spurious response mirror T-structure

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Reduction behavior of iron ore powder by high-volatile coal in thermogravimetric-gas chromatographic and kinetic analysis

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Journal of Iron and Steel Research(international) 2024年第1期31卷 92-107页

作者： Rui-meng Shi Qi-yuan Mi Bin Li Xiao Shi Chong Zou Jing Guo Han-jie Guo school of Metallurgical engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina China international engineering Consulting Corporation Beijing100048China school of Metallurgical and Ecological engineering University of Science and Technology BeijingBeijing100083China

The reduction behavior of iron ore powder by high-volatile coal was investigated,and its kinetic mechanism was *** effect of volatiles in coal on the reduction reaction of iron ore was compared by utilizing a Xinjiang lignite with a high volatile content and its pyrolysis carbon produced by high-temperature pyrolysis to remove volatiles,serving as a *** mass loss and gas composition of the samples during the reduction process were detected using thermo-gravimetric analysis and gas chromatography,and the morphological changes of iron ore powder were observed through scanning electron *** kinetic parameters of the iron oxide reduction reaction were calculated by the Flynn-Ozawa-Wall method,and the kinetic mechanism of volatile participation in the iron oxide reduction reaction was determined through the Coats-Redfern *** results indicate that the coupling effect between the high-volatile coal pyrolysis and reduction reactions occurs during the second stage of the entire coupling process,which corresponds to the late stage of coal pyrolysis with a substantial release of H_(2)and *** volatiles in coal actively participated in the reduction reaction,reducing the initiation temperature of the reaction by around 200℃.The reduction of iron oxides by high-volatile coal was jointly promoted by the"hydrogen cycle"and"carbon cycle",resulting in a higher reduction extent and metallization rate at the end of the *** high-volatile coal was used as the reductant,the average activation energy for the entire process was 76.5 kJ/mol,a significant decrease compared to the employment of pyrolysis carbon without volatiles as the reductant(1167 kJ/mol).

关键词： Direct reduction High-volatile coal Volatile Kinetics Reduction mechanism

Density-based ship detection in SAR images:Extension to a self-similarity perspective

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Chinese Journal of Aeronautics 2024年第3期37卷 168-180页

作者： Xueqian WANG Gang LI Zhizhuo JIANG Yu LIU You HE Department of Electronic engineering Tsinghua UniversityBeijing 100084China Shenzhen international Graduate school Tsinghua UniversityShenzhen 518055China

Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of SAR *** SAR ship detectors often independently handle small sub-images cropped from a large marine SAR image and do not exploit the nonlocal self-similarity *** this paper,we propose a new ship detector from the perspective of nonlocal self-similarity in SAR images to improve the ship detection performance,basically including three stages:prescreening,intra-cue calculation,and inter-cue *** the prescreening stage,we design a new Histogram-based Density(HD)feature to rapidly select candidate sub-images potentially containing ship targets from a large SAR *** the intra-cue calculation stage,target cues within a single candidate sub-image are *** the inter-cue calculation stage,thanks to the nonlocal self-similarity among different candidate sub-images in terms of density features,we innovatively extract a weighted superpixel-HD map to obtain accumulated intracues across all the candidate ***,for each candidate sub-image,we fuse its inter-cue and intra-cue to obtain final detection *** results based on real SAR images show that our newly proposed method provides a better target-to-clutter contrast and ship detection performance than those of other state-of-the-art detection approaches.

关键词： Ship detection Synthetic aperture radar(SAR) Density Self-similarity Histogram

Multiple-dimensioned defect engineering for graphite felt electrode of vanadium redox flow battery

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Carbon Energy 2024年第2期6卷 143-153页

作者： Yingqiao Jiang Yinhui Wang Gang Cheng Yuehua Li Lei Dai Jing Zhu Wei Meng Jingyu Xi Ling Wang Zhangxing He school of Chemical engineering North China University of Science and TechnologyTangshanChina Tsinghua Shenzhen international Graduate school Institute of Materials ResearchTsinghua UniversityShenzhenChina

The scarcity of wettability,insufficient active sites,and low surface area of graphite felt(GF)have long been suppressing the performance of vanadium redox flow batteries(VRFBs).Herein,an ultra-homogeneous multipledimensioned defect,including nano-scale etching and atomic-scale N,O codoping,was used to modify GF by the molten salt ***_(4)Cl and KClO_(3) were added simultaneously to the system to obtain porous N/O co-doped electrode(GF/ON),where KClO_(3) was used to ultra-homogeneously etch,and O-functionalize electrode,and NH4Cl was used as N dopant,***/ON presents better electrochemical catalysis for VO_(2)+/VO_(2)+ and V3+/V2+ reactions than only O-functionalized electrodes(GF/O)and *** enhanced electrochemical properties are attributed to an increase in active sites,surface area,and wettability,as well as the synergistic effect of N and O,which is also supported by the density functional theory ***,the cell using GF/ON shows higher discharge capacity,energy efficiency,and stability for cycling performance than the pristine cell at 140 mA cm^(−2) for 200 ***,the energy efficiency of the modified cell is increased by 9.7% from 55.2% for the pristine cell at 260 mA cm^(−2).Such an ultra-homogeneous etching with N and O co-doping through“boiling”molten salt medium provides an effective and practical application potential way to prepare superior electrodes for VRFB.

关键词： graphite felt molten salt N O co-doping ultra-homogeneous etching vanadium redox flow battery

Recent progress of two-dimensional metal-base catalysts in urea oxidation reaction

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Rare Metals 2024年第8期43卷 3607-3633页

作者： Qi-Xiang Huang Fang Wang Yong Liu Bi-Ying Zhang Fang-Ya Guo Zhong-Qiu Jia Hao Wang Tian-Xiang Yang Hai-Tao Wu Feng-Zhang Ren Ting-Feng Yi school of Materials Science and engineering Henan University of Science and Technology school of Environmental engineering and Chemistry Luoyang Institute of Science and Technology Henan Province international Joint Laboratory of Materials for Solar Energy Conversion and Lithium Sodium Based Battery school of Chemistry and Life Sciences Suzhou University of Science and Technology school of Materials Science and engineering Northeastern University

Urea oxidation reaction(UOR) is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption,which can produce hydrogen more efficiently by low theoretical potential,reduce the average cost of electrochemical hydrogen production,and is a frontier research hotspot for renewable hydrogen ***-dimensional(2D) nanomaterials as electrocatalysts have many favorable potential,such as it can effectively reduce the resistivity of materials and increase the specific surface area with *** paper reviews the application of 2D materials in UOR in alkaline *** a cross-sectional comparison of various material performance data including overpotential,Tafel slope,electrochemical active surface area(ECSA) and it stability test was conducted,which could illustrate the differences between materials composed of different *** addition,the main challenges hindering the progress of research on 2D materials in urea electrocatalysis processes and promising materials in this field in future are summarized and *** is believed that this review will contribute to designing and analyzing highperformance 2D urea electrocatalysts for water splitting.

关键词： Water splitting Urea oxidation reaction Two-dimensional Transition metal compounds Nobleon-noble metals

深度学习分子动力学模拟助力无铅（K,Na）NbO3铁电材料相变及纳米畴结构研究（英文）

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Science China Materials 2024年第9期67卷 3029-3038页

作者：张旭李蓓邹冀刘韩星徐贲刘凯 school of Materials Science and engineering Research Center for Materials Genome EngineeringWuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology international school of Materials Science and engineering Wuhan University of Technology Graduate school China Academy of Engineering Physics

通过多态结构和畴动力学调控,无铅KxNa1-xNbO3（KNN）可拥有优异的铁电和压电性能,并因此获得持续关注.尽管通过组分、相和畴结构等测量可以优化KNN的铁电性能,然而,该体系铁电性能的原子尺度机理仍是一个亟待解决的问题.本文通过训练... 详细信息

通过多态结构和畴动力学调控,无铅KxNa1-xNbO3（KNN）可拥有优异的铁电和压电性能,并因此获得持续关注.尽管通过组分、相和畴结构等测量可以优化KNN的铁电性能,然而,该体系铁电性能的原子尺度机理仍是一个亟待解决的问题.本文通过训练具有从头算精度的深度学习势（DP）,对不同K/Na比例（x=0.25～1.0）的KNN展开了分子动力学模拟研究.DP模型在描述不同相结构下的KNbO3和K0.5Na0.5NbO3的状态方程、弹性常数和声子色散关系等特性上表现出极高的准确性,证实了DP模型的适用性和可扩展性.分子动力学模拟的结果表明,KNN （x=0.25～1.0）的顺电-铁电相变主要受到有序-无序效应的驱动;而位移效应在随后的铁电相变中占主导地位.特别地,随着Na含量的增加,K/Na离子半径差异会引起明显的氧八面体畸变,导致90°畴壁形成更加困难.可以预见的是,基于DP的原子模拟有助于为储能和换能材料的复杂结构、热力学和铁电特性的探索提供一个准确和高效的计算模拟解决方案.

关键词： KNN molecular dynamics deep potential phase transitions domain dynamics

Triple signal amplification electrochemical sensing platform for Hg^(2+) in water without direct modification of the working electrode

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Frontiers of Environmental Science & engineering 2024年第7期18卷 157-167页

作者： Liuyin Hu Jiahua Cui Tao Lu Yalin Wang Jinping Jia school of Environmental Science and engineering Shanghai Jiao Tong UniversityShanghai 200240China school of Chemistry and Chemical engineering Shanghai Jiao Tong UniversityShanghai 200240China international Copper Association Ltd.Shanghai 200020China

An ultrasensitive electrochemical biosensor to detect trace Hg^(2+)in environmental samples was developed utilizing nanogold-decorated magnetic reduced graphene oxide(MrGO-AuNPs),exonuclease III-assisted target cycle(Exo Ⅲ-ATC)and hybridization chain reaction(HCR)synergistic triple signal *** MrGO-AuNPs is a superior carrier for capture DNA(cDNA)and acts as magnetic media for automatic separation and *** innovative utilization of the magnetism and improved sensing efficiency obviates the need for direct modification and repeated polishing of the working ***,the three DNA hairpins(cDNA,methylene blue(MB)labeled HP1 and HP2)further contribute to biosensor specificity and *** cDNA captures Hgt,it activates Exo Ⅲ-ATC due to the formation of a sticky end in the DNA stem via thymine-Hig-thymidine(T-Hg^(2+)-T),this leads to the hydrolysis of self-folded DNA by Exo Ⅲ-ATC to form"key"DNA(kDNA).The kDNA subsequently initiates HCR,resulting in massive super-sandwich structures(kDNA-[HP1/HP2])carrying signaling molecules on MrGO-AuNPs,and this overall structure serves as a signal probe(SP).Leveraging magnetic adsorption,the SP was automatically adsorbed onto the magneto-glass carbon electrode(MGCE),generating an amplified *** biosensor's detection limit(LOD)was 3.14 pmol/L,far below the limit of 10 nmol/L for mercury in drinking water set by the US *** biosensor also showed excellent selectivity when challenged by interfering ions,and the results of its application in actual samples indicate that it has good potential for practical applications in environmental monitoring.

关键词： Electrochemical sensing Hg^(2+) Amplification Graphene Hybridization chain reaction ExonucleaseⅢ