Search results for " física"
showing 10 items of 920 documents
El trabajo práctico en la enseñanza de las ciencias: una revisión
1996
Resumen basado en el de la publicación Resumen en inglés Se presenta una revisión sobre la efectividad de las prácticas en educación científica en los niveles secundario y terciario. A través de la revisión de más de cien referencias, se concluye que no se han proporcionado argumentos sólidos para justificar la gran cantidad de recursos materiales y humanos necesarios para la implementación de esta herramienta educativa. A pesar de estos resultados decepcionantes, los autores no se niega el papel central de las prácticas en la educación científica y se justifican estos resultados negativos al invocar la gran complejidad del tema, la ambigüedad que rodea el término «prácticas», y una metodol…
Modified Donnan phenomena in polyaniline with poly(vinyl sulphonate) chains
1993
We develop a physical model, based on the modified Donnan phenomena ideas introduced previously by the authors, to describe the acid doping of the conducting polymer polyaniline. The theory is motivated by the experimental work of Asturias et al. [Ber. Bunsenges. Phys. Chem. 95, 1381 (1991)]. Good agreement between theory and experiment is found.
DLPNO-CCSD(T) scaled methods for the accurate treatment of large supramolecular complexes
2017
In this work, we present scaled variants of the DLPNO-CCSD(T) method, dubbed as (LS)DLPNO-CCSD(T) and (NS)DLPNO-CCSD(T), to obtain accurate interaction energies in supramolecular complexes governed by noncovalent interactions. The novel scaled schemes are based on the linear combination of the DLPNO-CCSD(T) correlation energies calculated with the standard (LoosePNO and NormalPNO) and modified (Loose2PNO and Normal2PNO) DLPNO-CCSD(T) accuracy levels. The scaled DLPNO-CCSD(T) variants provide nearly TightPNO accuracy, which is essential for the quantification of weak noncovalent interactions, with a noticeable saving in computational cost. Importantly, the accuracy of the proposed schemes is…
Vibronic structure in triatomic molecules : The hydrocarbon flame bands of the formyl radical (HCO). A theoretical study
1998
A theoretical study of the vibrational structure of the math 2A′ ground and math 2A′ excited states of the formyl radical, HCO, and its deuterated form, DCO, has been performed. The potential energy surfaces have been computed by means of a multiconfigurational perturbative method, CASPT2. The computed geometries and the harmonic and anharmonic frequencies are successfully compared to the available experimental information. The vibrational intensities of the transition math 2A′↔math 2A′ have been computed both for absorption and emission. The results lead to accurate determinations of several structural parameters and some reassignments of the vibrational transitions of the so-called hydroc…
Nonlocal van der Waals Approach Merged with Double-Hybrid Density Functionals: Toward the Accurate Treatment of Noncovalent Interactions
2015
Noncovalent interactions drive the self-assembly of weakly interacting molecular systems to form supramolecular aggregates, which play a major role in nanotechnology and biochemistry. In this work, we present a thorough assessment of the performance of different double-hybrid density functionals (PBE0-DH-NL, revPBE0-DH-NL, B2PLYP-NL, and TPSS0-DH-NL), as well as their parent hybrid and (meta)GGA functionals, in combination with the most modern version of the nonlocal (NL) van der Waals correction. It is shown that this nonlocal correction can be successfully coupled with double-hybrid density functionals thanks to the short-range attenuation parameter b, which has been optimized against ref…
The new version of the pictorial scale of Perceived Movement Skill Competence in Spanish children: Evidence of validity and reliability. [La nueva ve…
2019
The purpose of this study was to i) examine reliability and construct validity of the pictorial scale of Perceived Movement Skill Competence (PMSC) aligned to the third version of the Test of Gross Motor Development (TGMD-3) in a sample of Spanish children; and to ii) analyse the validity of the PMSC and children’s perceived motor competence (MC) according to gender. A convenience sample of 361 children (55.7% boys) between 4 and 11 years-old participated. The pictorial scale of PMSC (19 items) was administered (a random subsample repeated the PMSC twice). Test-retest reliability using Intraclass Correlation Coefficients and construct validity using a Bayesian Structural Equation Modeling a…
Development and Preliminary Validation of Social Media as an Educational and Professional Tool Student Perceptions Scale (SMEPT-SPS)
2021
Although social media has an increasing presence both in university and sports settings, in the sports-management education context, no instruments (without being focused on one particular social-media platform, e.g., Facebook and Twitter) have been developed and validated that globally allow the academy to explore the perceptions of sports-management students concerning the educational and professional learning potential that these tools offer. Therefore, this research’s main objective is to develop and perform a preliminary validation of the social media as an educational and professional tool student perceptions scale (SMEPT-SPS). This study sample was composed of 90 Spanish undergraduat…
Análise técnico-tático no Taekwondo com coordenadas polares através de software HOISAN
2015
Se lleva a cabo un análisis de coordenadas polares en Taekwondo de las acciones realizadas por los hombres finalistas y semifinalistas en los Juegos Olímpicos de Londres 2012. Para este análisis, se consideraron como categorías focales las acciones relativas a la efectividad de uno, dos y tres puntos, y como categorías condicionadas variables técnico-tácticas para establecer las diferentes relaciones entre las diversas categorías relacionadas con el comportamiento técnico-táctico de los deportistas y la consecución de punto/s. Los resultados mostraron una relación, de excitación en las perspectivas retrospectiva y prospectiva, entre las conductas CAN (Acción de contraataque), CIR (Pierna de…
Analysis of the covers of textbooks of Primary Physical Education
2017
Esta investigación analiza las imágenes del cuerpo humano y el tipo de actividad física que practica en las portadas de los libros de texto del área de Educación Física (EF) en Educación Primaria (EP), para determinar si reproducen y transmiten estereotipos en relación al sexo, raza, cuerpo, discapacidad y actividad física en función del currículum. La muestra universo consta de 30 portadas, publicadas bajo la Ley Orgánica de Educación (LOE). Los resultados muestran portadas preferentemente dibujadas y en color, los protagonistas de la actividad física son niños y niñas conjuntamente (agrupación mixta), pero a la vez permanecen estereotipos de raza (blanca) y somatotipo (ectomorfo) realizan…
Las actividades de lucha
2003
La lucha, como práctica lúdica y agonística está vinculada a la historia de todos los pueblos y civilizaciones. Su origen se remonta a los albores de la humanidad, por la necesidad de defender la propia vida y la integridad física frente a situaciones de peligro para la supervivencia. Así, para someter violentamente al adversario, a lo largo de la historia y en las diversas civilizaciones, se desarrollaron en cada región del mundo distintas técnicas de combate que, en unos casos, utilizaban armas y, en otros, el propio cuerpo, según las necesidades y circunstancias. Hoy en día, la lucha se conserva principalmente de dos formas: a) Bien adaptada a las formas convencionales del deporte modern…