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Science China(Technological Sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu GUO XiaoXiang SUN yuTong WANG Gang LONG WeiMin LIAW Peter k. REN JingLi School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China Sk. of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HEAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HEA was prepared using molecular dynamics simulation involving melt and quench *** HEA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-pack.d structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HEA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

Physico-Mechanical Characteristics of Earth Brick. Stabilized with Cement and Padouk.Sawdust Residues

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Open Journal of Applied Sciences 2024年第7期14卷 1788-1806页

作者： Gabin alex Nouemssi Bennis Amine Martin Ndibi Mbozo’O Bonaventure Djeumak. Dok. k. Valery Guy Edgar Ntamack LA2MP: Laboratory of Mechanics Materials and Photonics National School of Agro-Industrial Sciences ENSAI Ngaoundr Cameroun Department of Mechanical and Production Engineering National School of Agro-Industrial Sciences ENSAI Ngaoundr Cameroun LMTM: Laboratory of Mechanics Materials and Thermal National School of Mineral Industry ENIM Rabat Morocco LEMA: Laboratory of Energertic and Applied Mechanics University of Abomey-Calavi Cotonou Benin GMMA: Group of Mechanics Materials and Acoustics Department of Physics Faculty of Sciences-EGCIM Ngaoundr Cameroun

The objective of this work.is to improve the physical and mechanical properties of stabilized earth block. (BTC) used in construction in the Ndé department of Cameroon. To achieve this, two stabilizers, cement and sawdust, were used at varying percentages of 0%, 4%, 6%, and 8%. Physical characterization tests, including natural water content, specific weight, jar test, Protor, and Atterberg limits, were conducted. Additionally, mechanical tests, such as compression and three-point bending, were performed. The results show that as the amount of stabilizer increases, the density of BTC decreases. The samples with 8% sawdust have the highest density, while those without stabilizers have the lowest. Porosity decreases as sawdust and cement content increases, with smaller values observed in samples with 8% sawdust or cement. Our tests indicate that block. stabilized with cement have slightly higher compressive strength than those stabilized with sawdust. However, the water absorption rate increases with higher sawdust content.

关键词： Earth block Cement Sawdust Physico-mechanical Characteristics Bangante West Cameroon

Two-photon emission from a superlattice-based superconducting light-emitting structure

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Light(Science & Applications) 2024年第7期13卷 1331-1340页

作者： Shlomi Bouscher Dmitry Panna Ronen Jacovi Fauzia Jabeen Christian Schneider Sven Höfling alex Hayat Department of Electrical Engineering TechnionHaifa 32000Israel. Technische Physik Universität WürzburgAm HublandD-97074 WürzburgGermany. Institute of Physics Carl von Ossietzky Universität OldenburgD-26111 OldenburgGermany

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and *** example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper ***,the twophoton nature of the emission has not been shown experimentally *** demonstrate two-photon emission in a GaAs/AlGaAs *** electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(Tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,T))demonstrate temperature-dependent time coincidences below Tc between photons emitted from the *** results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.

关键词： photon quantum utilizing

Finite element analysis and experimental validation of polymer-metal contacts in block.on-ring configuration

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Friction 2024年第3期12卷 554-568页

作者： k.y.Eayal AWWAD k.osro FALLAHNEZHAD B.F.yOUSIF Ahmad MOSTAFA Omar ALAJARMEH A.SHALWAN Xuesen ZENG Mechanical Engineering Department Faculty of EngineeringTafila Technical UniversityTafila 66110Jordan Medical Device Research Institute College of Science and EngineeringFlinders UniversitySouth Australia 5042Australia Centre for Future Materials University of Southern QueenslandToowoomba 4350Australia Department of Manufacturing Engineering Technology Public Authority for Applied Education and TrainingKuwait 13092Kuwait

The wear profile analysis,obtained by different tribometers,is essential to characterise the wear ***,most of the available methods did not tak. the stress distribution over the wear profile in consideration,which causes inaccurate *** this study,the wear profile of polymer–metal contact,obtained by block.on-ring configuration under dry sliding conditions,was analysed using finite element modelling(FEM)and experimental ***’s wear equation was integrated into a developed FORTRAN-UMESHMOTION code link.d with Abaqus software.A varying wear coefficient(k.values covering both running-in and steady state regions,and a range of applied loads involving both mild and severe wear regions were measured and implemented in the *** FEM was in good agreement with the *** model reproduced the stress distribution profiles under variable testing conditions,while their values were affected by the sliding direction and maximum wear depth(hmax).The largest area of the wear profile,exposed to the average contact stresses,is defined as the normal *** the critical zones were characterized by high stress concentrations reaching up to 10 times of that at the normal *** wear profile was mapped to identify the critical zone where the stress concentration is the k.y point in this *** surface features were examined in different regions using scanning electron microscope(SEM).Ultimately,SEM analysis showed severer damage features in the critical zone than that in the normal zone as proven by ***,the literature data presented and considered the wear features the same at any point of the wear *** this study,the normal zone was determined at a stress value of about 0.5 MPa,whereas the critical zone was at about 5.5 *** wear behaviour of these two zones showed totally different features from one another.

关键词： polymer-to-metal contact block.on-ring wear profile wear model

Special topic on organic and perovsk.te photovoltaics

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Science China Chemistry 2019年第7期62卷 797-799页

作者： Hongzheng Chen yongfang Li alex k.-y. jen State k.y Laboratory of Silicon Materials Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education) Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Department of Materials Science and Engineering University of Washington Seattle WA 98195 USA Department of Chemistry and Department of Materials Science & Engineering City University of Hong Kong Kowloon 999077 Hong Kong China

Photovoltaics, as a green technology for converting solar energy into electricity, have shown great promise to address the energy and environmental challenges for the sustainability of human society. In recent years, two types of photovoltaics, consisting of organic semiconductors or perovsk.tes as light absorbers, have experienced a rapid development. The development of organic solar cells (OSC) can be dated back.to 1986, since the discovery of a bi layer OSC by Di. C. W. Tang. Nowadays, OSCs made with polymer donors and small molecule acceptors have surpassed power conversion efficiencies (PCEs) of 16% for single-junction and 17% for tandem devices, through integrated innovative efforts on materials, interfaces, and device architectures.

关键词： perovsk.te photovoltaics electricity environmental challenges

Analysis of the Impact of the Blazhk. Effect Both on the Van Hoof Effect and Radial Velocity Amplitude in the Star RR Lyr

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Research in Astronomy and Astrophysics 2024年第6期24卷 253-272页

作者： y.El jariri F.L.Sefyani A.Benhida Z.Benk.aldoun k.k.lenberg k.Chafouai A.Habib M.Sabil Observatoire de l'Ouk.imeden LPHEAFSSMUniversitéCadi AyyadMarrakech2390Morocco Observatoire de l'Ouk.imeden LPHEAFSTGUniversitéCadi AyyadMarrakech549Morocco Département de physique Universitéd'Anvers Avenue Groenenborger 171Anvers2020Belgium LICPM ENSA-BMUniversitéSultan Moulay SlimaneBeni-Mellal23020Morocco

The Van Hoof effect is a phase shift existing between the radial velocity curves of hydrogen and metallic lines within the atmosphere of pulsating *** this article,we present a study of this phenomenon through the spectra of the brightest pulsating star RR Lyr of RR Lyrae stars recorded for 22 *** based ourselves,on the one hand,on 1268 spectra(41 nights of observation)recorded between the years 1994 and 1997 at the Observatory of Haute Provence(OHP,France)previously observed by Chadid and Gillet,and on the other hand on 1569 spectra(46nights of observation)recorded at our Ouk.imeden Observatory(Morocco)between 2015 and *** this study,we have detected information on atmospheric dynamics that had not previously been ***,the Van Hoof effect which results in a clear correlation between the radial velocities of hydrogen and those of the metallic lines has been observed and analyzed at different Blazhk. phases.A correlation between the radial velocities of different metallic lines located in the lower atmosphere has been observed as *** the first time,we were able to show that the amplitude of the radial velocity curves deduced from the lines of hydrogen and that of FeⅡ(λ4923.921?)increases toward the minimum of the Blazhk. cycle and decreases toward the maximum of the same Blazhk. ***,we found that the Van Hoof effect is also modulated by the Blazhk. ***,toward the minimum of the Blazhk. cycle the Van Hoof effect is more visible and at the maximum of the Blazhk. cycle,this effect is *** also observed the temporal evolution of the amplitudes of the radial velocities of the lower and upper *** observed over a long time,we can interpret it as a function of the Blazhk. phases.

关键词： stars:atmospheres stars:variables:RR Lyrae shock.waves techniques:spectroscopic techniques:radial velocities stars:individual(RR Lyr)

Tailored architecture of composite electrolyte for all-solid-state sodium batteries with superior rate performance and cycle life

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Nano Research 2024年第5期17卷 4171-4180页

作者： Xiang Guan Zhenhua Jian Xingan Liao Wenchao Liao yanfei Huang Dazhu Chen Robert k.y.Li Chen Liu Shenzhen k.y Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong KongChina

Seek.ng for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great ***,a unique strategy to tailor the architecture of composite electrolyte via inserting polymer chains into a small quantity of sulfate sodium grafted C_(48)0H_(28)O_(32)Zr_(6)(UIOSNa)is *** intimate contact between polymer segments and UIOSNa with limited pore size facilitates the anion immobilization of sodium salts and reduction of polymer crystallinity,thereby providing rapid ion conduction and reducing the adverse effect caused by the immigration of *** tNa+grafting of-SO_(3)Na groups on fillers allows the free movement of more sodium ions to further improve and ionic ***,even with the low content of UIOSNa fillers,a high ionic conductivity of 6.62×10^(-4) S·cm^(-1) at 60℃ and a transference number of 0.67 for the special designed composite electrolyte are *** assembled all-solid-state sodium cell exhibits a remark.ble rate performance for 500 cycles with 95.96%capacity retention at a high current rate of 4 *** corresponding pouch cell can stably work.for 1000 cycles with 97.03%capacity retention at 1 C,which is superior to most of the reported composite electrolytes in the literature.

关键词： solid state sodium battery composite electrolyte rate performance cycle life

A systematic review of climate change impacts,adaptation strategies,and policy development in West Africa

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Regional Sustainability 2024年第2期5卷 13-25页

作者： Camillus Abawiera WONGNAA alex Amoah SEyRAM Suresh BABU Department of Agricultural Economics Agribusiness and ExtensionKwame Nkrumah University of Science and TechnologyKumasi00233Ghana International Food Policy Research Institute Washington20005USA

Climate change studies are diverse with no single study giving a comprehensive review of climate change impacts,adaptation strategies,and policy development in West *** unavailability of an all-inclusive study to serve as a guide for practitioners affects the effectiveness of climate change adaptation strategies proposed and adopted in the West African *** purpose of this study was to review the impacts of climate change risk. on the crop,fishery,and livestock.sectors,as well as the climate change adaptation strategies and climate-related policies aimed at helping to build resilient agricultural production systems in West *** review process followed a series of rigorous stages until the final selection of 56 articles published from 2009 to ***,the results highlighted the adverse effects of climate change risk. on food *** found a continuous decline in food crop ***,the livestock.sector experienced morbidity and mortality,as well as reduction in meat and milk.*** fishery sector recorded loss of fingerlings,reduction in fish stock.,and destruction of mariculture and *** West Africa,climate-smart agriculture technologies,physical protection of fishing,and inclusion of gender perspectives in programs appear to be the major adaptation *** study therefore recommends the inclusion of ecosystem and biodiversity restoration,weather insurance,replacement of unsafe vessels,and strengthening gender equality in all climate change mitigation programs,as these will help to secure enough food for present and future generations.

关键词： Climate change Climate extreme events Food security Adaptation strategies Climate-smart agriculture West Africa

Coupled Cu doping and Z-scheme heterojunction for synergistically enhanced tetracycline photodegradation

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Nano Research 2024年第7期17卷 5937-5948页

作者： Huidong Shen Chunming yang Song Hong Leiduan Hao Liang Xu alex W.Robertson Zhenyu Sun Country State k.y Laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Shaanxi k.y Laboratory of Chemical Reaction Engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China Department of Physics University of WarwickCoventry CV 47ALUK

Semiconductor-based photocatalysis by utilizing solar energy for sustainable organic pollutant elimination has been a promising tactic to alleviate environmental ***,the development of robust and efficient photocatalysts to degrade organic pollutants still faces major challenges because of insufficient charge *** we design and fabricate a heterojunction consisting of copper,carbon-modified TiO_(2),and sulfur-doped g-C_(3)N_(4)nanosheets(i.e.,S-C_(3)N_(4)/Cu/C-TiO_(2)).The heterostructure affords a remark.ble synergistic photocatalysis for tetracycline hydrochloride degradation,achieving an 82.6%removal efficiency within 30 min under visible light irradiation,about 15.4 and 7.3 times higher than that of S-C_(3)N_(4)and C-TiO_(2),*** superior performance is attributed to the synergy between Cu doping and the Z-scheme heterojunction,which not only enhances the interfacial electric field effect,facilitating charge separation,but also boosts the redox *** charge carrier transfer between Cu/C-TiO_(2)and S-C_(3)N_(4)follows a Z-scheme,as verified by trapping experiments,electron spin-resonance spectroscopy,and density functional theory ***,the tetracycline hydrochloride degradation pathways are enunciated by liquid chromatograph mass spectrometry *** work.provides an effective approach for constructing high-performance photocatalysts that have potential in environmental remediation.

关键词： photocatalysis Cu doping Z-scheme heterojunction electrons and holes separation tetracycline degradation

Hybrid-Vlasov simulation of soft X-ray emissions at the Earth’s dayside magnetospheric boundaries

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Earth and Planetary Physics 2024年第1期8卷 70-88页

作者： M.Grandin H.k.Connor S.Hoilijok. M.Battarbee y.Pfau-k.mpf U.Ganse k.Papadak.s M.Palmroth Department of Physics University of HelsinkiHelsinkiFinland NASA Goddard Space Flight Center GreenbeltMD20771USA Space and Earth Observation Centre Finnish Meteorological InstituteHelsinkiFinland

Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing *** Solar wind Magnetosphere Ionosphere Link.Explorer(SMILE)and Lunar Environment heliospheric X-ray Imager(LEXI)missions aim to obtain soft Xray images of near-Earth space thank. to their Soft X-ray Imager(SXI)*** earlier modeling work. have already simulated soft X-ray images as might be obtained by SMILE SXI during its mission,the numerical models used so far are all based on the magnetohydrodynamics description of the space *** investigate the possible signatures of ion-k.netic-scale processes in soft Xray images,we use for the first time a global hybrid-Vlasov simulation of the geospace from the Vlasiator *** simulation is driven by fast and tenuous solar wind conditions and purely southward interplanetary magnetic *** first produce global X-ray images of the dayside near-Earth space by placing a virtual imaging satellite at two different locations,providing meridional and equatorial *** then analyze regional features present in the images and show that they correspond to signatures in soft X-ray emissions of mirrormode wave structures in the magnetosheath and flux transfer events(FTEs)at the *** results suggest that,although the time scales associated with the motion of those transient phenomena will lik.ly be significantly smaller than the integration time of the SMILE and LEXI imagers,mirror-mode structures and FTEs can cumulatively produce detectable signatures in the soft X-ray *** instance,a local increase by 30%in the proton density at the dayside magnetopause resulting from the transit of multiple FTEs leads to a 12%enhancement in the line-of-sight-and time-integrated soft X-ray emissivity originating from this ***,a proton density increase by 14%in the magnetosheath

关键词： magnetosphere magnetosheath numerical simulation SMILE LEXI soft X-ray emissions hybrid-Vlasov model polar cusp flux transfer events mirror-mode waves