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Scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-ni-Y/Sm alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 954-965页

作者： Yimeng Chen Manuel Legrée jean-Louis Bobet Alexander Kvit CAMECA Instruments Inc MadisonWI 53711USA ICMCB Universitéde BordeauxPessacCEDEX 33608France nIAC&Materials Science Department University of WisconsinMadisonWI 53706USA

The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg *** current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-ni-Y/Sm ternary alloys after extended isothermal *** on the alloying elements and their concentrations,Mg-ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg ***-STEM and APT indicate non-stoichiometric LPSO with incomplete ni_(6)(Y/Sm)_(8) *** addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of ni within the Mg bonding *** results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.

关键词： Magnesium alloys Long-range ordering Atom probe tomography(APT) STEM HAADF Hydrolysis properties.

Lateral ring compression test applied to a small caliber steel jacket:Identification of a constitutive model

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Defence Technology（防务技术） 2024年第6期36卷 133-148页

作者： Yann Coget Yael Demarty Christophe Czarnota Anthony Bracq jean-Sebastien Brest Alexis Rusinek French-German Research Institute of Saint-Louis 5 Rue Du General Cassagnou68300 Saint-LouisFrance Laboratoire d'Etude des Microstructures et de Mecanique des Materiaux(LEM3) CNRSUniversite de LorraineArts&Metiers ParisTechF-57000 MetzFrance

The evolution of threats and scenarios requires continuous performance improvements of ballistic protections for armed *** a modeling point of view,it is necessary to use sufficiently precise material behavior models to accurately describe the phenomena observed during the impact of a projectile on a protective *** this context,the goal of this paper is to characterize the behavior of a small caliber steel jacket by combining experimental and numerical *** experimental method is based on the lateral compression of ring specimens directly machined from the thin and small *** speeds and temperatures are considered in a quasi-static regime in order to reveal the strain rate and temperature dependencies of the tested *** Finite Element Updating Method(FEMU)is *** results are coupled with an inverse optimization method and a finite element numerical model in order to determine the parameters of a constitutive model representative of the jacket *** of the present model are verified against experimental results and a parametric study as well as a discussion on the identified material parameters are *** results indicate that the strain hardening parameter can be neglected and the behavior of the thin steel jacket can be described by a modeling without strain hardening sensitivity.

关键词： Full metal jacket ammunition Lateral ring compression Inverse identification numerical simulation

Improving the utility of locally differentially private protocols for longitudinal and multidimensional frequency estimates

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Digital Communications and networks 2024年第2期10卷 369-379页

作者： Héber H.Arcolezi jean-François Couchot Bechara Al Bouna Xiaokui Xiao Inria andÉcole Polytechnique(IPP) PalaiseauFrance Femto-ST Institute Univ.Bourg.Franche-ComtéUBFCCNRSBelfortFrance TICKET Lab. Antonine University Hadat-BaabdaBaabdaLebanon School of Computing National University of SingaporeSingaporeSingapore

This paper investigates the problem of collecting multidimensional data throughout time(i.e.,longitudinal studies)for the fundamental task of frequency estimation under Local Differential Privacy(LDP)*** to frequency estimation of a single attribute,the multidimensional aspect demands particular attention to the privacy ***,when collecting user statistics longitudinally,privacy progressively ***,the“multiple”settings in combination(i.e.,many attributes and several collections throughout time)impose several challenges,for which this paper proposes the first solution for frequency estimates under *** tackle these issues,we extend the analysis of three state-of-the-art LDP protocols(Generalized Randomized Response–GRR,Optimized Unary Encoding–OUE,and Symmetric Unary Encoding–SUE)for both longitudinal and multidimensional data *** the known literature uses OUE and SUE for two rounds of sanitization(***),i.e.,L-OUE and L-SUE,respectively,we analytically and experimentally show that starting with OUE and then with SUE provides higher data utility(i.e.,L-OSUE).Also,for attributes with small domain sizes,we propose Longitudinal GRR(L-GRR),which provides higher utility than the other protocols based on unary ***,we also propose a new solution named Adaptive LDP for LOngitudinal and Multidimensional FREquency Estimates(ALLOMFREE),which randomly samples a single attribute to be sent with the whole privacy budget and adaptively selects the optimal protocol,i.e.,either L-GRR or *** shown in the results,ALLOMFREE consistently and considerably outperforms the state-of-the-art L-SUE and L-OUE protocols in the quality of the frequency estimates.

关键词： Local differential privacy Discrete distribution estimation Frequency estimation Multidimensional data Longitudinal studies

Detection of Burned Areas through Spectral Indices Analysis of Sentinel-2A Satellite Images in the Abokouamékro Wildlife Reserve (Central, Côte D’Ivoire)

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Open Journal of Applied Sciences 2024年第1期14卷 205-222页

作者： Bob Kouakou Kouadio Sié Ouattara Alain Clément jean-Marc Gala Bi Zaouri jean-Luc Kouadio Kouassi jean-Luc Edouard Kouakou n’guessan Laboratoire des Sciences et Technologies de la Communication et de l’Information (LSTCI) Institut National Polytechnique Houphou&#235t Boigny (INP-HB) Yamoussoukro C&#244te d’Ivoire Laboratoire des Sciences Agronomiques et Génie Rural Institut National Polytechnique Houphou&#235t Boigny (INPHB) Yamoussoukro C&#244te d’Ivoire Ecole de Géomatique et du Territoire (EGT) Abidjan C&#244te d’Ivoire LARIS SFR MATHSTIC Université d’Angers Angers France Centre Universitaire de Recherche et d’application en Télédétection (CURAT) UFR des Sciences de la Terre et des Ressources Minières Abidjan C&#244te d’Ivoire Laboratoire de Botanique UFR Biosciences Université Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire

In Côte d’Ivoire, the recurring and unregulated use of bushfires, which cause ecological damage, presents a pressing concern for the custodians of protected areas. This study aims to enhance our comprehension of the dynamics of burnt areas within the Abokouamékro Wildlife Reserve (AWR) by employing the analysis of spectral indices derived from satellite imagery. The research methodology began with the calculation of mean indices and their corresponding spectral sub-indices, including nDVI, SAVI, nDWI, nDMI, BAI, nBR, TCW, TCG, and TCB, utilizing data from the Sentinel-2A satellite image dated January 17, 2022. Subsequently, a fuzzy classification model was applied to these various indices and sub-indices, guided by the degree of membership α, with the goal of effectively distinguishing between burned and unburned areas. Following the classification, the accuracies of the classified indices and sub-indices were validated using the coordinates of 100 data points collected within the AWR through GPS technology. The results revealed that the overall accuracy of all indices and sub-indices declines as the degree of membership α decreases from 1 to 0. Among the mean spectral indices, nDVI-mean, SAVI-mean, nDMI-mean exhibited the highest overall accuracies, achieving 97%, 95%, and 90%, respectively. These results closely mirrored those obtained by sub-indices using band 8 (nDVI-B8, SAVI-B8, and nDMI-B8), which yield respective overall accuracies of 93%, 92%, and 89%. At a degree of membership α = 1, the estimated burned areas for the most effective indices encompassed 2144.38 hectares for nDVI-mean, 1932.14 hectares for mean SAVI-mean, and 4947.13 hectares for mean nDMI-mean. A prospective approach involving the amalgamation of these three indices could have the potential to yield improved outcomes. This study could be a substantial contribution to the discrimination of bushfires in Côte d’Ivoire.

关键词： Spectral Indices Wildfire Burned Areas Abokouamékro Wildlife Reserve Côte D’Ivoire

Deep eutectic solvent-driven self-assembly of metal mercaptide complexes with enzyme-mimicking activities for detection of uric acid through one-step cascade catalytic reaction

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Green Chemical Engineering 2024年第1期5卷 75-84页

作者： jean Claude Munyemana Jia Chen Xin Li Yangxia Han Hao Tang Hongdeng Qiu CAS Key Laboratory of Chemistry of northwestern Plant Resources and Key Laboratory for natural Medicine of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing100039China Department of Pharmacy Gansu Provincial HospitalLanzhou730000China

This work presents a generic strategy to create a series of metal mercaptides complexes via coordination selfassembly between transition metals(Mn,Cu,Co,Fe,and ni)and cysteine(Cys)by forming the sulfur-metal *** strategy involves dissolving metal chlorides and Cys into deep eutectic solvents(DES),followed by the precipitation of metal mercaptides complexes(such as Cys-Mn)by adding water as an antisolvent,where DES serves as the solvent,shape directing,and capping agent,thereby preventing the formation of other metal ***,the prepared complexes possess both laccase and peroxidase-like properties,allowing the design of a technique for the detection of L-3,4-dihydroxyphenylalanine(L-DOPA)and uric acid,*** prepared Cys-Mn can linearly oxidize L-DOPA with its concentrations from 0.1 to 130μM and the detection limit was calculated to be 75.5 n ***,the Cys-Mn can mimic the activity of peroxidase towards oxidization of o-phenylenediamine at neutral p H,allowing single-step and one-pot cascade reactions for visual and fluorometric measurements of uric acid(UA)that could work in the range of 0.2-500μM UA with a detection limit of 0.06μM and 0.054μМ,*** assay was successful in detecting UA in serum and urine samples with relative standard deviation(RSD)ranging from 7.3%to 10.2%and 3.0%-8.5%respectively,suggesting that it may prove useful in medical diagnostic testing.

关键词： Metal-mercaptides Deep eutectic solvents Self-assembly Peroxidase-mimic catalyst Uric acid detection

Evaluation of Rhizobium tropici-Derived Extracellular Polymeric Substances on Selected Soil Properties, Seed Germination, and Growth of Black-Eyed Peas (Vigna unguiculata)

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Agricultural Sciences 2024年第5期15卷 548-564页

作者： Jonathan Alunge Metuge Erneste Havugimana jean Rugandirababisha Zachary n. Senwo Marie Chantal Mutimawurugo Department of natural Resources and Environmental Sciences Alabama A & M University Normal AL USA Department of Crop Science College of Agriculture Animal Sciences and Veterinary Medicine University of Rwanda (UR-CAVM) Kigali Rwanda

Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMn). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.

关键词： Rhizobium tropici Extracellular Polymeric Substances Soil Respiration Soil Microbial Biomass Black-Eyed Peas

Virtual Transmission Solution Based on Battery Energy Storage Systems to Boost Transmission Capacity

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 466-474页

作者： Matías Agüero Jaime Peralta Eugenio Quintana Victor Velar Anton Stepanov Hossein Ashourian jean Mahseredjian Roberto Cárdenas Coordinador Eléctrico nacional SantiagoChile PGSTech Montreal Canada Ecole Polytechnique de Montréal Montréal Canada University of Chile Santiago Chile IEEE

The increasing penetration of variable renewable energy(VRE)generation along with the decommissioning of conventional power plants in Chile,has raised several operational challenges in the Chilean national Power Grid(nPG),including transmission congestion and VRE *** mitigate these limitations,an innovative virtual transmission solution based on battery energy storage systems(BESSs),known as grid booster(GB),has been proposed to increase the capacity of the main 500 kV corridor of the *** paper analyzes the dynamic performance of the GB using a wide-area electromagnetic transient(EMT)model of the *** GB project,composed of two 500 MVA BESS units at each extreme of the 500 kV corridor,allows increasing the transmission capacity for 15 min during n-1 contingencies,overcoming transmission limitations under normal operation conditions while maintaining system stability during *** dynamic behavior of the GB is also analyzed to control power flow as well as voltage *** results show that the GB is an effective solution to allow greater penetration of VRE generation while maintaining system stability in the nPG.

关键词： Battery energy storage system(BESS) grid booster transient stability voltage stability electromagnetic transient(EMT)

From Control Theory to Gravitational Waves

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Advances in Pure Mathematics 2024年第2期14卷 49-100页

作者： jean-Francois Pommaret CERMICS Ecole des Ponts Paris Tech Paris France

When D:ξ→η is a linear ordinary differential (OD) or partial differential (PD) operator, a “direct problem” is to find the generating compatibility conditions (CC) in the form of an operator D1:η→ξ such that Dξ = η implies D1η = 0. When D is involutive, the procedure provides successive first-order involutive operators D1,...,Dn when the ground manifold has dimension n. Conversely, when D1 is given, a much more difficult “inverse problem” is to look for an operator D:ξ→η having the generating CC D1η = 0. If this is possible, that is when the differential module defined by D1 is “torsion-free”, that is when there does not exist any observable quantity which is a sum of derivatives of η that could be a solution of an autonomous OD or PD equation for itself, one shall say that the operator D1 is parametrized by D. The parametrization is said to be “minimum” if the differential module defined by D does not contain a free differential submodule. The systematic use of the adjoint of a differential operator provides a constructive test with five steps using double differential duality. We prove and illustrate through many explicit examples the fact that a control system is controllable if and only if it can be parametrized. Accordingly, the controllability of any OD or PD control system is a “built in” property not depending on the choice of the input and output variables among the system variables. In the OD case and when D1 is formally surjective, controllability just amounts to the formal injectivity of ad(D1), even in the variable coefficients case, a result still not acknowledged by the control community. Among other applications, the parametrization of the Cauchy stress operator in arbitrary dimension n has attracted many famous scientists (G. B. Airy in 1863 for n = 2, J. C. Maxwell in 1870, E. Beltrami in 1892 for n = 3, and A. Einstein in 1915 for n = 4).

关键词： Differential Operator Differential Sequence Killing Operator Riemann Operator Bianchi Operator Cauchy Operator Control Theory Controllability Elasticity General Relativity

Characterization and Geotechnical Classification of Soils and Lateritic Gravelly Materials along the Songololo-Lufu Road Axis (Kongo Central Province, DR Congo)

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Journal of Geoscience and Environment Protection 2024年第5期12卷 355-372页

作者： jean-Luc Albini Tshupa Blaise Mutombo Kabulu Ivon ndala Tshiwisa Clément n’zau Umba-Di-Mbudi Geo-Hydro-Energy Research Group Geosciences Department Faculty of Sciences and Technologies University of Kinshasa Kinshasa Democratic Republic of Congo Geosciences Department Faculty of Sciences and Technologies University of Kinshasa Kinshasa Democratic Republic of Congo Geological and Mining Research Center (CRGM) Kinshasa Democratic Republic of Congo Polytechnic Faculty President Joseph Kasa-Vubu University Boma Democratic Republic of Congo

This study aims to characterize from a geotechnical point of view, the soils as well as the lateritic gravels along the Songololo-Lufu road route in the Kongo Central Province in the Democratic Republic of Congo (DRC). Ten soil samples and eight lateritic gravel samples were analysed and tested in the laboratory. For each sample, identification parameters were determined such as particle size analysis, natural water content, Atterberg limits (plasticity index and consistency index), but also compaction and lift parameters such as optimal water content, maximum dry density and CBR lift index. All materials and soils have been classified according to the Congolese Road Standard (nRC) and according to the American HRB classification. The test results show us that clay soils almost always contain between 70% and 90% fine fraction;the grained fraction represents less than 30% in clay samples. For lateritic gravels soils, the percentage of fine elements varies between 35% and 15%;in sand around 20%;the gravelly fraction represents a little more than 50% of the soil. The majority of soil facies encountered define a plasticity index lower than 15. As for the consistency index, we obtained values greater than 1, both for clayey soils and for gravelly soils. The classification according to nRC defined for these soils the types Ae1 and Ae2 for the clayey facies and the types GL1 and GL2 for the gravelly soils, while that of the HRB identified the classes and subclasses A-6 and A-7-6 for clayey soils, and subclass A-2-6 for gravelly soils. The optimal water content values obtained range between 10.2% and 23.10%;the maximum dry densities are between 1.66 and 2.07 t/m3 and the CBR index is between 6 and 26. As for the lateritic gravels materials of the Songololo region, the percentage of fine elements generally remains between 12% and 31%;the plasticity index is between 8 and 18;the optimal dry density is around 2 t/m3;the optimal water content is between 9.

关键词： Songololo-Lufu Lateritic Gravels Classification Geotechnical nRC