1,720,997 research outputs found
Exploring students’ views about basic concepts in introductory quantum mechanics
No full textLiterature in physics education shows that students still experience difficulties learning quantum mechanics, although it is now part of the high school curriculum and many research-based proposals are available. Prior works mostly focused on specific misconceptions and a clearer picture of students' ideas on general quantum concepts is still lacking. We addressed these issues by inspecting, through multiple correspondence analysis and cluster analysis, the responses given by 408 Italian high school and undergraduate students to a Likert scale questionnaire on quantum physics. From our preliminary results, we can conclude that the majority of students leave high school and enter university without a sound model of the quantum world
Le attitudini verso la fisica ed i fisici di studenti liceali: Un’analisi basata sulle corrispondenze multiple.
No full textIn questo lavoro si sono analizzate mediante due scale Likert le attitudini verso la fisica ed i fisici di 330 studenti di liceo che partecipavano ad attività extracurriculari presso il Dipartimento di Fisica “E. Pancini” di Napoli. L’analisi `e basata sui metodi delle corrispondenze multiple e della clusterizzazione gerarchica. Si sono identificati 3 profili di studenti: a) entusiasti acritici della fisica (18%); b) ben disposti verso la fisica, accettata come strumento necessario per la società (67%); c) demotivati che considerano la fisica difficile e inutile (15%). Questi profili sono stati interpretati come “universi simbolici” che possono spiegare motivazione, autoefficacia e rendimento in fisica
High school students’ attitudes towards physics and physicists: An analysis based on multiple correspondence analysis
No full textIn this paper we describe high school attitudes toward physics using Semiotic Dynamic Cultural Psychology Theory (SDCPT). A View of Physics questionnaire was used to collect data about the views on physics and physicists with 337 high school (16–18 years old) students. Data were analysed through Multiple Correspondence Analysis and Cluster Analysis. We identified four basic generalized meanings of physics. In particular, it turned out that students see physics as either: a) interesting and important for a technology-based society; b) quite interesting, but badly taught at school and not completely useful for society; c) difficult and irrelevant for society; d) fascinating and important to study at school, but with an underrated value for society. Our study supports the use of the SDCPT framework to refine interpretative models of students’ motivation towards physics and develop new ways of teaching physics at secondary and university level
Il ruolo dell’autoefficacia e della confidenza sulla conoscenza in fisica degli studenti di liceo.
No full textIn questo lavoro si `e indagato il ruolo dell’autoefficacia e della confidenza sulla conoscenza di argomenti di base di fisica, dalla meccanica alla fisica moderna. Il campione era costituito da 142 femmine e 188 maschi. L’autoefficacia `e stata misurata con un questionario validato mediante analisi fattoriale confermativa con cinque dimensioni latenti: auto-regolazione; metacognizione; competenza percepita; coinvolgimento; ansia. La confidenza `e stata misurata con il grado di sicurezza nelle risposte date. I risultati mostrano un effetto indiretto dell’autoefficacia e uno diretto della confidenza sulla conoscenza in fisica. Si discuteranno effetti di genere e di motivazione
Didattica della meccanica quantistica nei Licei: Una sperimentazione curricolare
No full textQuesto lavoro riguarda la sequenza didattica "BMQ - Le basi della Meccanica Quantistica", ad uso dei Licei. Nella prima fase erano stati individuati, ricorrendo all'analisi quantitativa, i temi percepiti come più semplici dagli studenti; su questa base erano stati progettati una sequenza di insegnamento e uno strumento di verifica, somministrati in via preliminare in alcune classi formate ad hoc nell'ambito del Piano Lauree Scientifiche (PLS). In questa comunicazione riporteremo invece i risultati della recente attività di formazione del personale docente, lo sviluppo del materiale didattico e i risultati preliminari della somministrazione in alcune classi pilota di Liceo Scientifico
Conductivity response of amorphous oxide interfaces to pulsed light illumination
No full textTwo-dimensional electron gases (2DEGs) formed at oxide interfaces show a large variety of functional properties of major physical interest. Here, the peculiar electric transport behavior of the 2DEG formed at the LGO/STO oxide interface is studied under the application of light pulses of different amplitude, duration, and repetition rate, and by varying the sample temperature from 8 to 300 K. The experimental results evidence a persistent photoconductivity, intimately related to the complex physics of this system. These findings suggest the possibility of using the oxide interfaces for advanced applications as, for example, energy conversion or information storage
Thickness effect on the structure and superconductivity of Nd1.2Ba1.8Cu3Oz epitaxial films
No full textWe have studied the effect of thickness on the structure and superconductivity of Nd1.2Ba1.8Cu3Oz (NdBCO) epitaxial films deposited on SrTiO3 (100) substrates. High-quality NdBCO films were deposited by high oxygen pressure sputtering. The samples have been carefully characterized by transport measurements and x-ray diffraction using conventional and synchrotron radiation sources. Two structural transformations are observed. The first one is a crossover from the orthorhombic and twinned structure, typical of thick samples, to a pseudotetragonal phase at thickness lower than 60 unit cells. The pseudotetragonal phase exhibits peculiar x-ray diffuse scattering around the Bragg reflections, associated with nanostructured twinned domains. The second one appears at a thickness lower than 20 unit cells and is assigned to a pseudotetragonal-tetragonal transition. The transport properties are not modified at the first crossover, while a substantial decrease in T-c and in the number of holes is observed at the pseudotetragonal-tetragonal transformation. Our results suggest that the structural rearrangement and the transport properties are explained by the ordering of Cu(1)O chains. A simple model, able to explain the experimental results and capturing the essential features of the Cu(1)O chains nucleation process in the R1+xBa2-xCu3O7-delta (R=Y and rare-earth elements) compounds, is presented
THICKNESS EFFECT ON THE STRUCTURE AND SUPERCONDUCTIVITY OF Nd1.2Ba1.8Cu3O7+x EPITAXIAL FILMS
No full textWe have studied the effect of thickness on the structure and superconductivity of Nd1.2Ba1.8Cu3O7+x (NdBCO) epitaxial films deposited on SrTiO3 (100) substrates. High quality NdBCO films were deposited by high oxygen pressure sputtering. The samples have been carefully characterized by transport measurements and X-ray diffraction using conventional and synchrotron radiation sources. Two structural transformations are observed. The first one is a crossover from the orthorhombic and twinned structure, typical of thick samples, to a pseudotetragonal phase at thickness lower than 60 unit cells. The pseudotetragonal phase exhibits peculiar X-ray diffuse scattering around the Bragg reflections, associated to nanostructured twinned domains. The second one appears at thickness lower than 20 unit cells and is assigned to a pseudotetragonal-tetragonal transition. The transport properties are not modified at the first crossover, while a substantial decrease of T-c and of the number of holes is observed at the pseudotetragonal-tetragonal transformation. Our results suggest that the structural rearrangement and the transport properties are explained by the ordering of Cu(I)O chains
Structure and properties of a class of CeO2-based biepitaxial YBa2Cu3O7-δ Josephson junctions
No full textAn innovative biepitaxial technique for the fabrication of YBa2Cu3O7−δ
artificial grain-boundary Josephson junctions is proposed. The structure was specifically designed to analyze the effects of anisotropy, both in the order parameter and in the crystallographic structure of YBa2Cu3O7−δ,
on the Josephson current crossing the artificial grain boundary. Samples are grown on vicinal (110) oriented SrTiO3
substrates, and a CeO2
film is employed as a seed layer. Crystallography and morphology of the samples are analyzed, thus allowing us to infer the nature of the grain boundary. Our measurements show that the obtained grain boundary, besides possessing a unique and complex structure, exhibits very peculiar Josephson and tunnel-like properties. The intrinsic flexibility of the biepitaxial technique is employed to modify the in-plane angle of the grain-boundary interface, allowing for the realization of symmetrical, asymmetrical, and intermediate configurations on the same substrate. Accordingly, junctions exhibiting different kinds of magnetic field dependence of the Josephson current are obtained on the same chip. Evidence of d-wave-induced effects and of a dielectric character of the barrier is obtained by the transport measurements
Development and validation of an instrument to measure students’ engagement and participation in science activities through factor analysis and Rasch analysis
No full textIn this study, we present a new instrument, the Participation and Engagement Scale (PES), for the evaluation of the students’ involvement in STEM-oriented activities. The instrument was administered to about 1000 secondary school students who participated in the activities of the Italian Piano Nazionale Lauree Scientifiche in Biology, Chemistry and Physics. The activities were carried out in a remote modality due to the COVID-19 restrictions. Through an exploratory and confirmatory factor analysis, it was possible to validate a two-factor structure of the instrument: satisfaction towards the activities and value of the activities. The proposed factor structure shows a good model fit, with each of the obtained scales displaying excellent reliability. Construct-related validation evidence was obtained through the Rasch analysis, which allowed further psychometric improvement of the instrument. Convergent validation evidence was established through a correlation with the academic motivation and perceived difficulties scales. Using the proposed instrument, we found no statistically significant relationships between engagement, the different types of science activities attended, and the intention to enrol in a STEM course. Implications of the study for the evaluation of public understanding of science activities in both remote and in-presence modalities are also discussed
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