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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 *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of 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 *** 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 *** 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

Fatigue and Corrosion Fatigue Properties of Mg-Zn-Zr-Nd Alloys in Glucose-Containing simulated Body Fluids

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Acta Metallurgica sinica(English Letters) 2024年第9期37卷 1533-1550页

作者： Xue han Dan Zhang song Zhang Mohammed r.i.Abueida Lili Tan Xiaopeng Lu Qiang Wang huanye Liu school of Materials science and Engineering Shenyang University of TechnologyShenyang110870China school and hospital of stomatology China Medical UniversityShenyang110001China shi-Changxu innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China shenyang National Laboratory for Materials science Northeastern UniversityShenyang110819China

Medical bone implant magnesium(Mg)alloys are subjected to both corrosive environments and complex loads in the human *** increasing number of hyperglycemic and diabetic patients in recent years has brought new challenges to the fatigue performance of Mg ***,it is significant to study the corrosion fatigue(CF)behavior of medical Mg alloys in glucose-containing simulated body fluids for their clinical ***,the corrosion and fatigue properties of extruded Mg-Zn-Zr-Nd alloy in hank’s balanced salt solution(hBss)containing different concentrations(1 g/L and 3 g/L)of glucose were *** average grain size of the alloy is about 5μm,which provides excellent overall mechanical *** conditional fatigue strength of the alloy was 127 MPa in air and 88 MPa and 70 MPa in hBss containing 1 g/L glucose and 3 g/L glucose,*** crack initiation points for alloys in air are oxide inclusions and in solution are corrosion *** corrosion rate of the alloy is high at the beginning,and decreases as the surface corrosion product layer thickens with the increase of immersion *** corrosion products of the alloy are mainly Mg(Oh)_(2),MgO and a small amount of Ca-P *** electrochemical results indicated that the corrosion rate of the alloys gradually decreased with increasing immersion time,but the corrosion tendency of the alloy was greater in hBss containing 3 g/L *** the one hand,glucose accelerates the corrosion process by adsorbing large amounts of aggressive Cl^(-)*** the other hand,glucose will be oxidized to form gluconic acid,and then reacts with Mg(Oh)_(2) and MgO to form Mg gluconate,which destroys the corrosion product film and leads to the aggravation of corrosion and the accumulation of fatigue damage.

关键词： Mg alloys Corrosion fatigue Glucose Gluconic acid Corrosion product

rational design of AgGas/Zns/Zns quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials science & Technology 2024年第2期169卷 235-242页

作者： h.X.Lu h.Liu Z.Z.Fu Y.Y.Chen h.Q.Dai Z.hu W.L.Zhang r.Q.Guo institute for Electric Light sources School of Information Science and TechnologyFudan UniversityShanghai 200433China institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China Yiwu research institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint innovation Center Zhongshan 528437China

in this study,a two-step method was used to synthesize highly luminescent AgGas/Zns/Zns quantum dots(QDs).in the first step,an inner Zns shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGas core and the outer Zns shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesized AgGas/Zns/Zns QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AgGas ***,the effect of halogen ions in Zn precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and Zns shelling ***,the Zns shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the i^(−)-rich *** work provides insights into the interfacial restructuring during the Zns shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGas Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

Nonlinear rydberg exciton-polaritons in Cu2O microcavities

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Light(science & Applications) 2024年第4期13卷 619-627页

作者： Maxim Makhonin Anthonin Delphan Kok Wee song Paul Walker Tommi isoniemi Peter Claronino Konstantinos Orfanakis sai Kiran rajendran hamid Ohadi Julian heckötter Marc Assmann Manfred Bayer Alexander Tartakovskii Maurice skolnick Oleksandr Kyriienko Dmitry Krizhanovskii Department of Physics and Astronomy University of SheffieldSheffield S37RHUK. Department of Physics and Astronomy University of ExeterStocker RoadExeter EX44PYUK. sUPA School of Physics and AstronomyUniversity of St AndrewsSt Andrews KY169SSUK. Fakultät Physik TU DortmundAugust-Schmidt-Straße 444227 DortmundGermany

rydberg excitons(analogues of rydberg atoms in condensed matter systems)are highly excited bound electron-hole states with large Bohr *** interaction between them as well as exciton coupling to light may lead to strong optical nonlinearity,with applications in sensing and quantum information ***,we achieve strong effective photon–photon interactions(Kerr-like optical nonlinearity)via the rydberg blockade phenomenon and the hybridisation of excitons and photons forming polaritons in a Cu2O-filled *** pulsed resonant excitation polariton resonance frequencies are renormalised due to the reduction of the photon-exciton coupling with increasing exciton *** analysis shows that the rydberg blockade plays a major role in the experimentally observed scaling of the polariton nonlinearity coefficient as∝n4.4±1.8 for principal quantum numbers up to n=*** high principal quantum numbers studied in a polariton system for the first time are essential for realisation of high rydberg optical nonlinearities,which paves the way towards quantum optical applications and fundamental studies of strongly correlated photonic(polaritonic)states in a solid state system.

关键词： density rydberg polar

search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 TeV using CMs open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.Mahmoud h.Abdallah M.T.hussein s.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

in this study,we conducted a search for dark matter using a part of the data recorded by the CMs experiment during run-i of the LhC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−*** data were gathered from the CMs open *** matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.Thus,the search was conducted in the dimuon plus large missing transverse momentum *** benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the CMs open *** evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider CMs open data search for new physics dark fermion

Model dependent analysis of ■→■ decays in beyond standard model

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Chinese Physics C 2024年第9期48卷 86-99页

作者： s.Mahata M.Mandal h.Mahapatra s.Biswas s.sahoo Department of Physics National Institute of Technology Durgapur

Motivated by the recent experimental results of branching fractions for ■→■ decays,which deviate from their sM predictions,we hve investigated these decays in W' model and scalar leptoquark model to determine potential signatures of new physics(NP) in semileptonic charm decays induced by c→■ *** recent experimental results of branching fractions for semileptonic D meson decays,new coupling parameters are predicted for the aforementioned NP *** fraction,forward-backward asymmetry,and lepton polarization asymmetry are examined by considering the predicted NP coupling *** results of branching fractions in scalar leptoquark model are found very close to the experimental results and exist around the range of 1σ *** presented a comparative study of the NP models to check their sensitivity on these *** anticipate that further research on these decays will significantly support our findings.

关键词： $ W' $ boson charm decay flavour changing charged current new physics scalar leptoquark

Tilted global solar irradiance in Bahrain:an experimental study

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Clean Energy 2024年第2期8卷 27-34页

作者： N.Vasilikos C.Georgantopoulou h.Alajaimi s.h.Almajed M.Ahmed D.Mathioulakis school of Mechanical Engineering Bahrain PolytechnicIsa TownPO Box 33349Kingdom of Bahrain school of Mechanical Engineering National Technical University of AthensHeroon Polytechniou 7 StZografos 15773AthensGreece

in the present work,tilted global solar irradiance data are presented and analysed,measured for a period of 1 year on the campus of Bahrain Polytechnic,Kingdom of Bahrain,from both a fixed photovoltaic panel and a moving one via a two-axis solar *** fixed panel faces south with an angle of 26°with respect to the horizontal,coinciding with the local geographical *** second panel is moved by two motors,controlled by a global positioning system and suitable software so that the sun’s rays are perpendicular to the panel surface.A pyranometer is installed on each panel,recording the tilted global solar irradiance,stored by using a data *** analysis of the data obtained shows a 33%solar energy gain on an annual basis for the moving panel(2780 versus 2088 kWh/m^(2) on the fixed panel).More importantly,in June,when the energy demand in Bahrain is elevated due to the increased residential cooling loads,the solar energy received by the moving panel is 54.7%higher compared with that of the fixed *** a percentage basis,the increase in solar energy from the moving panel is profound in the early morning and late evening ***,the reduction in the solar energy received by the fixed panel from May to June does not appear in the moving panel because of the adjustable orientation of the *** the year,the mean daily solar power varies between 0.37 and 0.56 kW/m^(2) for the fixed panel,and 0.45 and 0.70 kW/m^(2) for the moving *** winter,solar energy fluctuations are elevated due to erratic weather conditions that present a peak standard deviation of 28%of the corresponding *** data presented are useful for potential solar investments in Gulf countries.

关键词： tilted solar irradiance renewable energy solar tracking photovoltaic Gulf Cooperation Council Countries

Twinning aspects and their efficient roles in wrought Mg alloys:A comprehensive review

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Journal of Magnesium and Alloys 2024年第6期12卷 2201-2230页

作者： s.s.A.shah Manping Liu Azim Khan Farooq Ahmad M.r.Abdullah Xingquan Zhang shiwei Xu Zhen Peng school of Materials science and Engineering Jiangsu UniversityZhenjiang 212013China school of Mechanical Engineering Anhui University of TechnologyMáanshan 243002China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China

Twinning is widely recognized as an effective and cost-efficient method for controlling the microstructure and properties of wrought magnesium(Mg)***,twins play a crucial role in initiating dynamic recrystallization(DrX),while twin regions experience rapid recrystallization during static recrystallization(srX).The activation of twinning can lead to changes in lattice orientation,significantly impacting the final texture in Mg *** active roles of twinning are influenced by various factors during the activation process,and the mobility of twin boundaries(TB)can be amplified by stress effects,dislocation interactions,and thermal ***,annealing treatments that involve proper segregation or precipitation on TBs serve to stabilize them,restraining their *** such as segregation may also alter the twinning propensity in Magnesium-rare earth(Mg-rE)***{10–11}contraction twins(CT)and{10–11}-{10–12}double twins(DT)can promote dynamic recrystallization(DrX),they also pose a risk as potential sources of voids and ***,understanding the nucleation and growth mechanisms of twinning is crucial,and these aspects are briefly reviewed in this *** the factors mentioned above,this article summarizes the recent research progress in this field,shedding light on advancements in recent eras.

关键词： Mg alloys Twinning recrystallization Texture Mechanical properties

Leading directions and effective distance of larch offspring dispersal at the upper treeline in the Northern and Polar Urals, russia

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Forest Ecosystems 2024年第5期11卷 603-617页

作者： P.A.Moiseev V.L.semerikov T.V.semerikova D.s.Balakin i.B.Vorobiev s.O.Viuykhin institute of Plant and Animal Ecology Ural BranchRussian Academy of SciencesEkaterinburg620144Russia Center for Genetics and Life science Sirius University of Science and Technology354340SochiRussia

Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the *** rate of advance has been extremely variable–from tens to hundreds meters in *** is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical *** resulting stand pattern is the consequence of the interaction between dispersal and survival functions.A few publications have addressed the question of how this pattern is *** order to understand how the spatial structure of tree stands was formed at the upper limit of their distribution in the Ural Mountains,we assessed the distance and direction of dispersal of offspring from maternal *** found that in frontal Larix sibirica ***,‘effective’dispersal of offspring ranges from 3 to 758 m(with a median of 20–33 m in open forest and 219 m in single-tree tundra in the Polar Urals and 107 m in open forest in the Northern Urals).We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds,but also in the opposite direction up the slope,and the distance can reach 500–760 *** data obtained can be used to develop an individual-based model which is capable of simulating in detail the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change.

关键词： Effective dispersal distance Upper treeline Parentage analysis Age estimation Terrestrial laser scanning Larix sibirica Ural mountains