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possible Origin of Magnetic Fields in Very Dense Stars

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Chinese physics Letters 2004年第11期21卷 2117-2119页

作者： a.pérezMartínez H.pérezRojas H.J.MosqueraCuesta GrupodeFisicaTeorica ICIMAFCalleENo.309VedadoLaHabanaCuba CentroBrasileirodepesquisasFísicas LaboratóriodeCosmologiaeFísicaExperimentaldeAltasEnergiasRuaDr.XavierSigaud150Cep22290-180.UrcaRiodeJaneiroRJBrazil

We discuss the bosonization of a relativistic very dense Fermi gas in a magnetic field and the consequent Bose-Einstein condensation of the resulting relativistic vector gas of charged particles. The model may be a.plied to paired spin-up electrons. We show that such systems may maintain self-consistently magnetic fields of order 10(10) - 10(13) G. That pairing could be the origin of large magnetic fields in some white dwarfs and neutron stars. For fields large enough (similar to10(13) for white dwarfs), the system becomes unstable and collapses.

关键词： Quantum gases liquids and solids Gravitation and cosmology Statistical physics and nonlinear systems Astrophysics and astroparticles

Weather or weathering?Growth of Nothofagus dombeyi on volcanic soils differing in nitrogen and phosphorus concentrations

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Journal of plant Ecology 2016年第5期9卷 596-607页

作者： Christoph Walter Cecilia a.pérez Frank M.Thomas Faculty of Regional and Environmental Sciences GeobotanyUniversity of TrierBehringstraße 2154296 TrierGermany Departamento de Ecología de Ecosistemas Instituto de Ecología y Biodiversidad(IEB)Alameda 340SantiagoChile

Aims We tested whether—in addition to weather conditions—the concentrations of nitrogen and phosphorus in the substrate have an effect on the radial stem increment of Nothofagus dombeyi trees in old-growth forest stands on volcanic soil at the western slopes of the Andes in South-Central *** We took soil sa.ples and tree increment cores from five proximate sites(1000-1300 m a.s.l.)that are located in the volcanic region of the Conguillío National park and differ in the age of the substrate(Miocene—3500 years B.p.)and in its concentrations of nitrogen(N)and phosphorus(p).The soil sa.ples were also analysed on their concentrations of other plant mineral nutrients,carbon(C)and nitrogen isotope ratios(δ^(15)N).Tree-ring widths and the stem basal area increment(BAI)were related to climate *** selected tree rings,the stable isotope ratios of carbon(δ^(13)C)and oxygen(δ^(18)O)were determined and related to growth and climate *** FindingsConsistent with theory,the soils on the oldest substrate showed the highest(least negative)δ^(15)N values,but mineral N was the only nutrient whose concentration exhibited a straightforward(increasing)relationship with increasing substrate *** BAI was largest on the soil with the highest concentration of plant-available *** contrast to BAI,tree-ring chronologies did not differ among the study ***,tree-ring chronologies and BAI exhibited significantly positive correlations with summer precipitation,and negative correlations,with summer(December)temperature.A negative correlation was found betweenδ^(13)C and precipitation anomalies in the growing season(November-March).We interpret the negative correlations between growth and temperature,and betweenδ^(13)C andδ^(18)O in the tree rings,as an impairment of net carbon assimilation by anomalously warm weather conditions during the growing *** conclude that the growth of *** is mainly affected by high temperature and low precipitation

关键词： Andisol annual ring dendroecology temperate broadleaf forest weather anomalies

Ca-based materials derived from calcined cigarette butts for CO_(2)capture and thermochemical energy storage

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Journal of Environmental Sciences 2024年第6期140卷 230-241页

作者： Nabil Amghar Virginia Moreno pedro E.Sánchez-Jiménez Antonio perejón Luis a.pérez-Maqueda Instituto de Ciencia de Materiales de Sevilla C.S.I.C.-Universidad de SevillaC.Américo Vespucio4941092 SevillaSpain Instituto de Tecnología de Materiales(ITM) Universitat Politècnica de València(UPV)Plaza Ferrándiz y Carbonell 1AlcoyAlicante 03801Spain Departamento de Química Inorgánica Facultad de QuímicaUniversidad de Sevilla41012 SevillaSpain

Cigarette butts(CBs)are one of the most common types of litter in the *** to the toxic substances they contain,the waste generated poses a harmful risk to the environment,and therefore there is an urgent need for alternative solutions to landfill ***,this work presents a.possible revalorization of this waste material,which implies interesting environmental *** were used as sacrificial templates for the preparation of CaO-based materials by impregnation with calcium and magnesium nitrates followed by flaming *** materials presented enhanced porosity for their use in the Calcium Looping process a.plied either to thermochemical energy storage or CO_(2)capture *** influence of the concentration of Ca and Mg in the impregnating solutions on the multicycle reactivity of the sa.ples was *** improved multicycle performance was obtained in terms of conversion for both a.plications.

关键词： Cigarette butts Calcium-Looping CO_(2)Capture Thermochemical energy storage

Quantum Instability of Magnetized Stellar Objects

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Chinese Journal of Astronomy and Astrophysics 2005年第4期5卷 399-411页

作者： R.González Felipe H.J.Mosquera Cuesta a.pérez Martínez H.pérez Rojas Departamento de Física and Centro de Física Teórica de partículas Instituto Superior TécnicoAv.Rovisco Pais1049-001 LisboaPortugal Instituto de Cosmologia Relatividade e Astrofísica(ICRA-BR)Centre Brasileiro de Pesquisas FísicasRua Dr.Xavier Sigaud 150CEP 22290-180UreaRio de JaneiroRJBrazil Centro Latino-Americano de Física Avenida Wenceslau Braz 71CEP 22290-140 fundosBotafogoRio de JaneiroBrazil Instituto de Cibernética Matemática y FísicaCalle E No.30910400 La HabanaCuba

The equations of state for degenerate electron and neutron gases are studied in the presence of magnetic *** including quantum effects in the investigation of the structural properties of these systems,it is found that some hypermagnetized stars can be unstable according to the criterion of stability of *** magnetized white dwarfs should collapse producing a supernova type Ia,while superstrong magnetized neutron stars cannot stand their own magnetic field and must implode,too.A comparison of our results with a set of the available observational data of some compact stars is also presented,and the agreement between this theory and observations is verified.

关键词： dense matter-equation of state-instabilities-stars:magnetic fields-stars:neutron white dwarfs

Kinematic alterations after two high-intensity intermittent training protocols in endurance runners

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Journal of Sport and Health Science 2019年第5期8卷 442-449页

作者： Felipe García.pinillos Alejandro Molina-Molina Juan a.párraga-Montilla.pedro A.Latorre-Román Department of Corporal Expression University of JaenJaen 23071Spain Human Lab Sport and Health University Institute(iMUDS)Granada 18007Spain

purpose:This study aimed to evaluate running kinematic characteristics during the early and late stages of 2 high-intensity intermittent training(HIIT)protocols with similar external load but different average running pace,as well as to compare the fatigue-induced changes during both HIIT protocols at a kinematic ***:Eighteen endurance runners were tested on a track on 2 occasions:10 runs of 400 m with 90-120 s recovery between running bouts(10 × 400 m),and 40 runs of 100 m with 25-30 s recovery between running bouts(40 × 100 m).Heart rate was monitored during both protocols;blood lactate accumulation and rate of perceived exertion were recorded after both exercises.A high-speed camera was used to measure sagitta.plane kinematics at the first and last runs during both HIIT *** dependent variables were spatial-temporal parameters(step length and contact and flight time),joint angles during support(relative angles of the hip,knee,and ankle),and foot strike ***:High levels of exhaustion were reached by the athletes during both workouts(blood lactate accumulation>12 mmol/L,rate of perceived exertion>15;peak heart rate(HRpeak)>176 bpm).A within-protocol paired t test(first *** run)revealed no significant changes(p≥0.05)in kinematic variables during any of the HIIT sessions.A between-protocol comparison with the first run of each protocol revealed the effect of running speed on kinematics:+2.44 km/h during the 40 × 100 m:shorter contact and flight time(pp length(p= 0.001);greater hip flexion(p = 0.031)and ankle extension(p = 0.001)at initial contact;smaller knee and ankle flexion(pp extension at toe-off(pperformed at intensity above the velocity associated with maximal oxygen uptake did not consistently perturb the running kinematics of trained endurance runners.

关键词： Biomechanics Fatigue-induced Runners Running Training Two-dimensional

THE MAIN MEGAMORpHOSTRUCTURES AND GEODEpRESSION(DIWA) TECTONICS OF THE EASTERN MARGIN OF ASIA-FROM MESOZOIC TO pRESENT

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Geotectonica et Metallogenia 1994年第Z2期18卷 18-19页

作者： KULAKOV a.p pacificInstituteofGeography Far-EasternBranchoftheRussianAcademyofSciences.VladivostokRussia

Unlocking hypoglycemia–associated brain microvascular dysfunction:critical insights from proteomic analysis

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Neural Regeneration Research 2025年第6期20卷 1707-1708页

作者： Siva S.V.p.Sakamuri Anil Sakamuri Department of Chemistry Auburn University at MontgomeryMontgomeryALUSA Vascular Biology Center and Department of Medicine Medical College of Georgia at Augusta UniversityAugustaGAUSA

Hypoglycemia-a critical complication linked to worsened brain function in diabetic subjects:Hypoglycemia is characterized by a decline in circulatory glucose levels below sta nda rd physiological *** hypoglycemia,classified as level 1 hypoglycemia,is defined by blood glucose levels below 70 mg/dL and can be effectively addressed through carbohydrate *** hypoglycemia,denoted by blood glucose levels less than 54 mg/dL,poses a life-threatening risk if left *** with type 1 and type 2 diabetes undergoing insulin treatment are particularly susceptible to hypoglycemia due to impaired counterregulatory mechanisms.

关键词： impaired intake critical

Do non-target species visit feeders and water troughs targeting small game?A study from farmland Spain using camera-tra.ping

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Integrative Zoology 2021年第2期16卷 226-239页

作者： JoséA.ARMENTEROS Jesús CARO Carlos SÁNCHEZ-GARCÍA Beatriz ARROYO Joséa.pÉREZ Vicente RGAUDIOSO Emilio J.TIZADO Department of Animal production Research Group on Game Species Breeding and ManagementUniversity of LeónLeónSpain Instituto de Investigación en Recursos Cinegéticos(IREC CSIC-UCLM-JCCM)Ciudad RealSpain Fundación Artemisan Ciudad RealSpain Department of Biodiversity and Environmental Management University of LeónPonferradaSpain

provision of food and water is a widespread tool implemented around the world for the benefit of game and other wildlife,but factors affecting the use of food and water by non-target species are poorly *** evaluated visits to feeders and water troughs by non-game species using camera-traps in two separate areas of *** and water troughs were either“protected”(when surrounded by more than 50%of shrubs/forest)or“open”(in the opposite case).A total of 18948 photos from 5344 camera-tra.ping days depicted animals,and 75 species were *** and water troughs were visited by target species(partridges and lagomorphs,55.3%of visits)and non-target species(44.7%of visits).Among the latter,corvids were themost common(46.1%of visits),followed by rodents(26.8%),other birds(23.6%,mainly passerines),columbids(1.9%),and other species at minor *** highest proportion of visiting days to feeders and water troughs was from corvids(0.173)followed by otherbirds(0.109)and rodents(0.083);the lowest proportion was recorded for columbids(0.016).Use intensity and visit frequency of water troughs tripled that recorded in feeders,and visits to open feeders/troughs were a.proximately twice those to protected *** summary:feeders and water troughs targeting small game species are also used regularly by non-target ones;they should be set close to cover to optimize their use by non-target species that are not competitors of target species(though corvids may visit them);water availability should be prioritized where drought periods are expected.

关键词： camera-tra.ping feeding game species management watering wildlife

Source of inorganic N affects the cost of growth in a legume tree species(Virgilia divaricata)from the Mediterrean-type Fynbos ecosystem

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Journal of plant Ecology 2016年第6期9卷 752-761页

作者： Anathi Magadlela María a.pérez-Fernández Aleysia Kleinert Léanne L.Dreyer Alex J.Valentine Botany and Zoology Department University of StellenboschPrivate Bag X1Matieland 7602South Africa Deparment of physical Chemical and Natural SystemsUniversidad Pablo de OlavideCarretera de Utrera Km 141013 SevilleSpain

Aims In Mediterranean-type ecosystem,the Cape Fynbos,legumes may be able to switch between soil N and atmospheric N_(2) sources during growth to adjust the carbon costs of N *** study investigated the utilization of different inorganic N sources by Virgilia divaricata,a native legume from the Mediterranean-type ecosystem of the Cape Floristic *** plants were cultivated in sterile quartz sand,supplied with 25%strength Long Ashton nutrient solution,modified to contain 500μM *** the phosphate level(500μM),plants were treated with 500μM NH_(4)NO_(3)(treatment named N),or grown in N-free nutrient solution and inoculated with effective Burkholderia sp.(Bact.)or treated with combined N sources(500μM NH_(4)NO_(3))and inoculated with effective Burkholderia sp.(N+Bact.).Important Findings The a.plication of NH_(4)NO_(3) to the legumes resulted in a greater increase in plant dry *** construction costs were higher in plants that were supplied with mineral and symbiotic N *** photosynthetic rates per leaf area was maintained,irrespective of the N *** the plant roots were nodulated,the plant dependence on N_(2) fixation decreased with addition of *** and nodules of the plants solely reliant on N_(2) fixation showed an increase in glutamine *** results show that *** is highly adapted for growth at the forest *** and possibly anthropic soils by utilizing both atmospheric and soil N sources.

关键词： phosphate deficiency Virgilia divaricata N_(2)fixation mineral N C construction costs a.paragine