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On Differential equations of Integrable Billiard Tables

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Acta Mathematica Sinica,english Series 2024年第1期40卷 417-424页

作者： Vladimir DrAGOVIC Andrey e.MIrONOV Department of Mathematical Sciences The University of Texas at DallasRichardson TXUSA Mathematical Institute SANU BelgradeSerbia Novosibirsk State University NovosibirskRussia Sobolev Institute of Mathematics of the Siberian Branch of the russian Academy of Sciences NovosibirskRussia

We introduce a method to find differential equations for functions which define tables,such that associated billiard systems admit a local first *** illustrate this method in three situations:the case of(locally)integrable wire billiards,for finding surfaces in r^(3)with a first integral of degree one in velocities,and for finding a piece-wise smooth surface in r^(3)homeomorphic to a torus,being a table of a billiard admitting two additional first integrals.

关键词： Polynomial first integrals wire billiards piece-wise smooth surfaces

BaTiO3 solid solutions co-doped with Gd3+ and eu3+:Synthesis,structural evolution and dielectric properties

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Journal of rare earths 2024年第10期42卷 1920-1926页

作者： r.Martínez-López M.Pérez-Labra J.A.romero-Serrano F.r.Barrientos-Hernández M.reyes-Pérez M.I.Valenzuela-Carrillo G.Urbano-reyes V.e.reyes-Cruz G.I.Dávila-Pulido Academic Area of earth Sciences and Materials Autonomous University of Hidalgo State Metallurgy and Materials Department ESIQIE-IPNUPALM Autonomous University of Coahuila Boulevard Adolfo López Mateos S/n

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO3solid solutions codoped with rare earth elements(Gd3+and eu3+) prepared using the solid-state reaction method are *** pure precursor powders of BaCl3,TiO2,Gd2O3,and eu2O3were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 MPa and sintered at 1300℃ in air atmosphere for 6 h to obtain Ba1-3xGd2xTi1-3xeu4xO3（x=0,0.0015,0.01 and0.1）.X-ray diffraction（XrD） and rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO3for the samples with x=0,0.0015 and 0.01, as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd3+and eu3+in the BaTiO3structure is reached for the sample with x>0.01,and the orthorhombic eu2TiO5and monoclinic BaTi2O5secondary phases were *** raman results show the characteristic peaks of ferroelectric tetragonal BaTiO3around 716 cm-1（LO of A1 symmetry）,515 cm-1（TO of A1 symmetry）,and 305 cm-1（B1）.The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃ with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and eu homogeneously distributed in the *** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO3 Doping europium Gadolinium rare earths Synthesis

Aulacaspis yasumatsui infestations accelerate Cycas leaf litter decomposition and nutrient release

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Pedosphere 2024年第3期34卷 681-684页

作者： Thomas e.MArLer Bagong Kaalaman Botanikal Institute 15 Rizal StreetBarangay MalabañasAngeles City 2009(Philippines)

Dear editor,Numerous aspects of ecosystem ecology are influenced by insects(Prasad,2022).Herbivory of plant organs by insects may influence the biogeochemistry of forests by changing the speed of litter decomposition(Schowalter,2022).Cycas micronesica *** is the only native gymnosperm in the Mariana *** once-abundant tree experienced no known lethal threats prior to the 2003 invasion of Guam by the scale Aulacaspis yasumatsui Takagi(Marler,2012).This insular case study has been the subject of abundant research(Marler et al.,2021).Changes to leaf litter chemistry improved litter quality following *** infestations(Marler and Dongol,2016),but the prediction of increased decomposition speed has not been confirmed with experimental incubations.

关键词： litter fir release

Commentary on "Association of daily sitting time and leisure-time physical activity with body fat among ***"

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Journal of Sport and Health Science 2024年第2期13卷 127-129页

作者： Barbara e.Ainsworth School of exercise and Health Shanghai University of SportShanghai 200438China

In their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among ***,Liao et al.^(1) analyzed data from the 2011-2018 National Health and examination Survey to examine associations between h/day sitting,meeting (or not meeting) the *** Activity Guidelines of≥150 min/week of moderate-and vigorous-intensity LTPA,and combinations of sitting time and LTPA on totaland trunk percent body fat (BF%).

关键词： U.S. adult among

exploration of chromene-based BioAIegens

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National Science review 2024年第3期11卷 47-48页

作者： Fritz e.Kühn Department of Chemistry&Catalysis research Center School of Natural Sciences Technical University of Munich

Photoemission efficiency is usually higher in solution than in solid *** compounds however, display a reverse behavior. Such a behavior is called aggregation-induced emission(AIe).

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Performance analysis of deep borehole heat exchangers for decarbonization of heating systems

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Deep Underground Science and engineering 2024年第3期3卷 349-357页

作者： Andreas e.D.Lund Department of electrical engineering and Automation Aalto UniversityEspooFinland

Meeting the climate change mitigation targets will require a substantial shift from fossil to clean fuels in the heating *** pumps with deep borehole exchangers are a promising solution to reduce *** the thermal behavior of deep borehole exchangers(DBHes)ranging from 1 to 2 km was analyzed for various heat flow profiles.A strong correlation between thermal energy extraction and power output from DBHes was found,also influenced by the heating profile *** operating time over the year typically resulted in higher energy production,while shorter one yielded higher average thermal power output,highlighting the importance of the choice of heating strategy and system design for optimal performance of *** breaks in operation for regenerating the borehole,for example,with waste heat,proved to be favorable for the performance yielding an overall heat output close to the same as with continuous extraction of *** results demonstrate the usefulness of deep boreholes for dense urban areas with less available *** the heat production from a single DBHe in Finnish conditions ranges from half up to even a few GWh a year,the technology is best suitable for larger heat loads.

关键词： clean energy deep borehole exchangers energy transition geothermal heat ground-coupled heat pump

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Climate refugia along Lake Superior’s shores:disjunct arctic-alpine plants rely on cool shoreline temperatures but are restricted to highly exposed habitat under climate warming

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Journal of Plant ecology 2024年第4期17卷 23-41页

作者： Ashley Hillman Scott e.Nielsen Department of renewable resources University of AlbertaEdmontonAB T6G 2R3Canada

Climate refugia can serve as a remnant habitat or stepping stones for species dispersal under climate *** largest freshwater lake by surface area,Lake Superior,USA and Canada,serves as a model system for understanding cooling-mediated local refugia,as its cool water temperatures and wave action have maintained shoreline habitats suitable for southern disjunct populations of arctic-alpine plants since ***,we seek to explain spatial patterns and environmental drivers of arctic-alpine plant refugia along Lake Superior’s shores,and assess future risk to refugia under moderate(+3.5℃)and warmest(+5.7℃)climate warming ***,we examined how the interactive effects of summer surface water temperatures and wind affected onshore temperatures,resulting in areas of cooler ***,we developed an ecological niche model for the presence of disjunct arctic-alpine refugia(pooling 1253 occurrences from 58 species)along the lake’s ***,we fit species distribution models for 20 of the most common arctic-alpine disjunct species and predicted presence to identify refugia ***,we used the two climate warming scenarios to predict changes in the presence of refugia and disjunct *** type,elevation above water,inland distance,July land surface temperature from MODIS/Terra satellite and near-shore depth of water were the best predictors of disjunct ***,we predicted 2236 km of the shoreline(51%)as disjunct refugia habitat for at least one species under current conditions,but this was reduced to 20% and 7% with moderate(894 km)and warmest(313 km)climate change projections.

关键词： climate refugia disjunct populations lake effect Lake Superior species distribution models

exploring the mass gap:Black holes in green pea galaxies

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 170-171页

作者： James e.rhoads School of earth and Space exploration Arizona State UniversityTempeAZ 85287USA

We know about black holes primarily on two mass scales(e.g.,see Figure 22 of ref.[1]).Supermassive black holes inhabit the centers of galaxies,where they sometimes power active galactic nuclei(AGN).Their populations can be probed through AGN surveys,tidal disruption event surveys,and(in the closest galaxies)stellar and gas dynamics in the innermost regions where the black hole dominates the gravitational potential.

关键词： galaxies tidal galactic

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Non-canonical BrAF variants and rearrangements in hairy cell leukemia

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Oncology research 2024年第9期32卷 1423-1427页

作者： STePHeN e.LANGABeer Cancer Molecular Diagnostics St.James’s HospitalDublinD08 W9RTIreland

Hairy cell leukemia(HCL)is an uncommon mature B-cell malignancy characterized by a typical morphology,immunophenotype,and clinical *** vast majority of HCL patients harbor the canonical BrAF V600e mutation which has become a rationalized target of the subsequently deregulated rAS-rAF-MeK-MAPK signaling pathway in HCL patients who have relapsed or who are refractory to front-line ***,several HCL patients with a classical phenotype display non-canonical BrAF mutations or *** include sequence variants within alternative exons and an oncogenic fusion with the IGH *** must be taken in the molecular diagnostic work-up of patients with typical HCL but without the BrAF V600e to include investigation of these uncommon ***,functional characterization,and reporting of further such patients is likely to provide insights into the pathogenesis of HCL and enable rational selection of targeted inhibitors in such patients if required.

关键词： Hairy cell leukemia BrAF Molecular diagnostics Targeted therapy