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Detection of Increasingγ-Ray Emissions from 4FGL J1718.5+4237 with Fermi-LAT

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Research in Astronomy and Astrophysics 2024年第8期24卷 169-174页

作者： Jiao Zheng pengfei zhang Li zhang Department of Astronomy School of Physics and AstronomyKey Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China School of Physics and Engineering Technology Xingyi Normal University for NationalitiesXingyi 562400China

We report a gradual brighteningγ-ray source,4FGL J1718.5+4237,in 0.1-500.0 GeV,which may be associated with a blazar NVSS J171822+423948 with a redshift of~*** analyzed 15.25 yr ofγ-ray data recorded by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detected significantγ-ray emissions in the direction of the blazar with a test statistic(TS)of~*** on timing analysis using a 1 yr time bin,we have observed a gradual brightening inγ-ray emissions from the *** our analysis,we categorize them into two states:Quiet(TS~0)and Loud(TS~226)states,with the distinction occurring in 2016 August(MJD57602.69).From the Quiet state to the brightest period(the last data point),theγ-ray flux in 0.1-500.0 GeV increased by more than 12-fold from<0.2×10^(-8)photons cm^(-1)s^(-1)to 2.6×10^(-8)photons cm^(-1)s^(-1).Additionally,we studied the spectral properties in detail for the Loud state and the overall *** no significant variation was detected,both exhibited a spectral indexΓof~*** origin of the brighteningγ-ray emissions from the target is not yet *** long-term multi-wavelength observations and studies will provide insight into the astrophysical mechanisms of the target.

关键词： galaxies active-blazars individual(4FGL J1718.5+4237)

General properties of the spectral form factor in open quantum systems

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Frontiers of physics 2024年第3期19卷 229-237页

作者： Yi-Neng Zhou Tian-Gang Zhou pengfei zhang Institute for Advanced Study Tsinghua UniversityBeijing 100084China Department of Physics Fudan UniversityShanghai 200438China

The spectral form factor(SFF)can probe the eigenvalue statistic at different energy scales as its time variable *** closed quantum chaotic systems,the SFF exhibits a universal dip-ramp-plateau behavior,which reflects the spectrum rigidity of the *** this work,we explore the general properties of SFF in open quantum *** find that in open systems the SFF first decays exponentially,followed by a linear increase at some intermediate time scale,and finally decreases to a saturated plateau *** derive general relations between(i)the early-time decay exponent and Lindblad operators;(ii)the long-time plateau value and the number of steady *** also explain the effective field theory perspective of general *** verify our theoretical predictions by numerically simulating the Sachdev−Ye−Kitaev(SYK)model,random matrix theory(RMT),and the Bose−Hubbard model.

关键词： spectral form factor open quantum system quantum chaos

Study on flow characteristics and phase holdup in a slurry bubble column coupled with mild agitation Author links open overlay panel

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Particuology 2024年第8期91卷 226-234页

作者： Qingyuan An Jiantao Li Lei zhang Nailiang Wang pengfei zhang Zhenghong Luo Chunxi Lu State Key Laboratory of High-Efficiency Coal Utilization and Green Chemical Engineering Ningxia UniversityYinchuan750021China State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of Petroleum BeijingBeijing102249China Department of Chemical&Biological Engineering Monash UniversityVictoria3800Australia

A pilot-scale experimental setup was constructed to investigate the effect of mild agitation on the bubble characteristics and phase holdup in a slurry bubble *** agitation positively impacts the axial uniform distribution of solid holdup,though it shows insignificant influence on the radial *** homogenous regime,mild agitation promotes the coalescence of bubbles,and the effect becomes stronger with increasing agitator *** mild agitation contributes to a decrease in bubble size in heterogeneous flow *** agitation presents a significant effect on the gas holdup by adjusting the bubble size and bubble motion *** modification was introduced to predict the gas holdup considering the effects of mild agitation,a necessary consideration for applications requiring mild *** adapted model predicts gas holdup with a maximum error of 12.9%.

关键词： Slurry bubble column Mild agitation Phase holdup Bubble characteristics

Transition-metal-catalyzed remote meta-C-H alkylation and alkynylation of aryl sulfonic acids enabled by an indolyl template

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Chinese Chemical Letters 2024年第8期35卷 254-259页

作者： pengfei zhang Qingxue Ma Zhiwei Jiang Xiaohua Xu Zhong Jin College of Chemistry State Key Laboratory of Elemento-organic ChemistryNankai UniversityTianjin 300071China Key Laboratory of Xinjiang Native Medicinal and Edible Plant Resource Chemistry College of Chemistry and Environmental SciencesKashi UniversityKashgar 844007China

Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of phenyl ***,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-H alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta ***,remote meta-selective C-H alkynylation of aryl sulfonic acids was also accomplished with a rhodium *** meta-C-H functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.

关键词： C-H functionalization Aryl sulfonic acid Site-selectivity Transition-metal catalysis Alkylation Alkynylation

An advanced 2D/3D g-C_(3)N_(4)/TiO_(2)@MnO_(2) multifunctional membrane for sunlight-driven sustainable water purification

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Nano Research 2024年第4期17卷 2368-2380页

作者： Fan Yu Chunjia Luo Xiaohan Niu Min Chao pengfei zhang Luke Yan Polymer Materials&Engineering Department School of Materials Science&EngineeringChang’an UniversityXi’an 710064China Key Laboratory of Road Construction Technology and Equipment MOEChang’an UniversityXi’an 710064China School of Textile Science and Engineering Xi’an Polytechnic UniversityXi’an 710064China

Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation ***,dense stacking and a single functionality have limited the membrane ***,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) *** 3D flower-like nanostructures broaden the transport channels of the composite *** membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic *** remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.

关键词： graphitic carbon nitride(g-C_(3)N_(4))based membrane three-dimensional(3D)nanostructures self-cleaning multifunction

Self-derivation and reconstruction of silver nanoparticle reinforced cobalt-nickel bimetallic hydroxides through interface engineering for overall water splitting

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Journal of Energy Chemistry 2024年第3期90卷 590-599,I0013页

作者： Yan Li Jie Han Weiwei Bao Junjun zhang Taotao Ai Mameng Yang Chunming Yang pengfei zhang National and Local Joint Engineering Laboratory for Slag Comprehensive Utilization and Environmental Technology School of Materials Science and EngineeringShaanxi University of TechnologyHanzhong 723000ShaanxiChina State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering College of Chemistry&Chemical EngineeringNingxia UniversityYinchuan 750021NingxiaChina College of Chemistry&Chemical Engineering Yan’an UniversityYan’an 716000ShaanxiChina School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Designing efficient and long-lasting non-metal electrocatalysts is an urgent task for addressing the issue of kinetic hysteresis in electrochemical oxidation *** bimetallic hydroxides,catalyzing the oxygen evolution reaction(OER),have significant research potential because hydroxide reconstruction to generate an active phase is a remarkable ***,the complete reconstruction of ultrathin CoNi(OH)_(2) nanosheets was achieved by embedding Ag nanoparticles into the hydroxide to induce a spontaneous redox reaction(SRR),forming heterojunction Ag@CoNi(OH)_(2) for bifunctional *** calculations and in situ Raman and ex situ characterizations revealed that the inductive effect of the Ag cation redistributed the charge to promote phase transformation to highly activate Ag-modified *** Co-Ni dual sites in Co/NiOOH serve as novel active sites for optimizing the intermediates,thereby weakening the barrier formed by OOH^*.Ag@CoNi(OH)_(2) required a potential of 1.55 V to drive water splitting at a current density of 10 mA cm^(-2),with nearly 98.6% Faraday *** ion induction and triggering of electron regulation in the OER via the synergistic action of the heterogeneous interface and surface reconstruction,this strategic design can overcome the limited capacity of bimetallic hydroxides and bridge the gap between the basic theory and industrialization of water decomposition.

关键词： Surface reconstruction Bimetallic hydroxides Ag nanoparticle Operando Raman Overall water splitting

The choice of antimicrobial polymers:Hydrophilic or hydrophobic?

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Chinese Chemical Letters 2024年第9期35卷 41-53页

作者： Zixu Xie pengfei zhang Ziyao zhang Chen Chen Xing Wang State Key Laboratory of Organic-Inorganic Composites Beijing Laboratory of Biomedical MaterialsCollege of Life Science and TechnologyBeijing University of Chemical TechnologyBeijing 100029China

Owing to the spread of COVID-19,it is difficult to ignore the existence and importance of antimicrobial polymers(AMPs)because most protective appliances are made of ***,bacteria prefer hydrophilic compounds,while fungi prefer hydrophobic *** recent decades,AMPs have made significant strides due to the versatile design of the functional groups or units for hydrophilic,hydrophobic,or amphiphilic *** review summarizes the advances of AMPs itself from the perspective of their ***,this study aims to clarify how the functional groups determine the interaction between the polymer and microorganisms directly affects the antimicrobial efficacy of the designed *** on the advances,the challenges and outlooks of AMPs from the perspective of wettability are systematically discussed to build a bridge between the structural design of AMPs and the requirements of practical applications.

关键词： Antimicrobial polymer Hydrophilicity Hydrophobicity Amphiphilicity Chiral terpene

Design and experimental study of the end-effector for broccoli harvesting

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 137-144页

作者： Xiong Zhao Gangji Xu pengfei zhang Gaohong Yu Yadan Xu Faculty of Mechanical Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China Key Laboratory of Transplanting Equipment and Technology of Zhejiang Province Hangzhou 310018China Hangzhou vocational&Technical College Hangzhou 310018China

The end-effector is an important part of the broccoli harvesting *** at the physical characteristics of a large broccoli head and thick stem,a spherical cutting tool broccoli harvesting end-effector was designed in this ***,the physical characteristics of broccoli were tested,and physical parameters such as the broccoli head diameter and stem diameter of broccoli were *** maximum cutting force of broccoli stems under different cutting angles was ***,according to the physical characteristics and harvesting process of broccoli,the end-effector was designed,and the mathematical model of kinematics and dynamics was *** on the results of dynamic analysis,the end-effector rod was optimized,and the unilateral width of the slider was 40 mm,the length of the connecting rod was 120 mm,and the length of the crank was 42 *** mechanism needed an external driving force of 140.54 N to cut the broccoli ***,a 32 mm cylinder with a load rate of 50%was selected as the power ***,the feasibility of the broccoli harvesting end-effector was verified by the harvesting *** showed that the overall harvesting success rate of the end-effector is 93.3%,and the smoothness rate of the stem section is 83.3%.The harvesting performance of the broccoli end-effector was *** lays a foundation for agricultural robots to harvest broccoli.

关键词： harvesting robot broccoli end-effector dynamic analysis mechanism optimization

Automated and miniaturized screening of antibiotic combinations via robotic-printed combinatorial droplet platform

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1801-1813页

作者： Fangchi Shao Hui Li Kuangwen Hsieh pengfei zhang Sixuan Li Tza-Huei Wang Department of Biomedical Engineering Johns Hopkins UniversityBaltimoreMD 21218USA Department of Mechanical Engineering Johns Hopkins UniversityBaltimoreMD 21218USA

Antimicrobial resistance(AMR)has become a global health crisis in need of novel *** this end,antibiotic combination therapies,which combine multiple antibiotics for treatment,have at-tracted significant attention as a potential approach for combating *** facilitate advances in anti-biotic combination therapies,most notably in investigating antibiotic interactions and identifying synergistic antibiotic combinations however,there remains a need for automated high-throughput plat-forms that can create and examine antibiotic combinations on-demand,at scale,and with minimal reagent *** address these challenges,we have developed a Robotic-Printed Combinatorial Droplet(RoboDrop)platform by integrating a programmable droplet microfuidic device that generates antibiotic combinations in nanoliter droplets in automation,a robotic arm that arranges the droplets in an array,and a camera that images the array of thousands of droplets in *** further implement a resazurin-based bacterial viability assay to accelerate our antibiotic combination *** a demonstration,we use RoboDrop to corroborate two pairs of antibiotics with known interactions and subsequently identify a new synergistic combination of cefsulodin,penicillin,and oxacillin against a model *** *** therefore envision RoboDrop becoming a useful tool to efficiently identify new synergistic antibiotic combinations toward combating AMR.

关键词： Droplet microfluidics Antimicrobial resistance Antibiotic combinatorial screening Contact printing Robotics Pharmaceutical analysis High-throughput Antibiotic interactions