Technologies, enseignement et apprentissage des mathématiques: Revue de questions

Texte complet des actes sur http://www.irem.univ-paris-diderot.fr/up/actes_seminaire_national_de_didactique/Actes%20du%20S%C3%A9minaire%20National%20de%20Didactique%202009.pdfInternational audienceCette revue de questions part de ce qu'il ressort de récents travaux centrés sur les technologies, tels qu'ils ont été présentés dans le cadre de l'étude ICMI 17 au Vietnam en décembre 2006, dans celui du groupe de travail " technologies and resources in mathematical education " au colloque CERME 6 qui s'est tenu en janvier 2009 à Lyon, ainsi que dans la demi journée TICE aucolloque Didirem de septembre 2008. Nous tentons de faire le point sur ce que sont actuellement les technologies pour l'enseignement des mathématiques et ce que peuvent être les recherches en didactique sur ce thème. Ensuite, nous nous intéressons aux questions d'apprentissage avec les technologies en nous focalisant sur la dimension expérimentale des mathématiques et posons des questions de recherche liées à l'usage des TICE pour développer cette dimension de l'activité des élèves. Nous abordons enfin la question de l'intégration des technologies dans l'enseignement, du pôle enseignant dans les recherches et du rôle des collectifs dans l'intégration des TICE. Les questions théoriques et les questions de méthodologies spécifiques ou non des TICE traversent tout l'exposé dans chacune des parties proposées

Problem-solving and Web resources at tertiary level

We organised two experimental teaching designs involving web resources in two different French universities. In this paper, we describe these experiments and analyse the students' behaviours. Our aim is to observe whether the use of specific online resources favours the development of problem-solving activities

Using E-Exercise Bases in Mathematics: Case Studies at University

En open access sur http://www.springerlink.com/content/k2k616x254q34236/?p=fa97ce28e2884c20834f83d7d8f92a2e&pi=1International audienceE-Exercise Bases (EEB) are now used in the teaching of mathematics, especially at university. We discuss here the consequences of their use on the students' activity during computer lab sessions. Results stem from observations of several teaching designs organised in different French universities with three e-exercise bases. The analysis focuses on new tasks and on specific solving strategies, which appear using these resources. Moreover, specific didactic contract clauses are studied

Problem-solving and Web resources at tertiary level

We organised two experimental teaching designs involving web resources in two different French universities. In this paper, we describe these experiments and analyse the students' behaviours. Our aim is to observe whether the use of specific online resources favours the development of problem-solving activities

Spectroscopy of 35^{35}P using the one-proton knockout reaction

The structure of $^{35}$P was studied with a one-proton knockout reaction at88~MeV/u from a $^{36}$S projectile beam at NSCL. The $\gamma$ rays from thedepopulation of excited states in $^{35}$P were detected with GRETINA, whilethe $^{35}$P nuclei were identified event-by-event in the focal plane of theS800 spectrograph. The level scheme of $^{35}$P was deduced up to 7.5 MeV using$\gamma-\gamma$ coincidences. The observed levels were attributed to protonremovals from the $sd$-shell and also from the deeply-bound $p\_{1/2}$ orbital.The orbital angular momentum of each state was derived from the comparisonbetween experimental and calculated shapes of individual ($\gamma$-gated)parallel momentum distributions. Despite the use of different reactions andtheir associate models, spectroscopic factors, $C^2S$, derived from the$^{36}$S $(-1p)$ knockout reaction agree with those obtained earlier from$^{36}$S($d$,\nuc{3}{He}) transfer, if a reduction factor $R\_s$, as deducedfrom inclusive one-nucleon removal cross sections, is applied to the knockout transitions.In addition to the expected proton-hole configurations, other states were observedwith individual cross sections of the order of 0.5~mb. Based on their shiftedparallel momentum distributions, their decay modes to negative parity states,their high excitation energy (around 4.7~MeV) and the fact that they were notobserved in the ($d$,\nuc{3}{He}) reaction, we propose that they may resultfrom a two-step mechanism or a nucleon-exchange reaction with subsequent neutronevaporation. Regardless of the mechanism, that could not yet be clarified, thesestates likely correspond to neutron core excitations in \nuc{35}{P}. Thisnewly-identified pathway, although weak, offers the possibility to selectivelypopulate certain intruder configurations that are otherwise hard to produceand identify.Comment: 5 figures, 1 table, accepted for publication in Physical Review

Introduction to the papers of TWG14: University mathematics education

International audienc

Search for new resonant states in 10C and 11C and their impact on the cosmological lithium problem

The observed primordial 7Li abundance in metal-poor halo stars is found to be lower than its Big-Bang nucleosynthesis (BBN) calculated value by a factor of approximately three. Some recent works suggested the possibility that this discrepancy originates from missing resonant reactions which would destroy the 7Be, parent of 7Li. The most promising candidate resonances which were found include a possibly missed 1- or 2- narrow state around 15 MeV in the compound nucleus 10C formed by 7Be+3He and a state close to 7.8 MeV in the compound nucleus 11C formed by 7Be+4He. In this work, we studied the high excitation energy region of 10C and the low excitation energy region in 11C via the reactions 10B(3He,t)10C and 11B(3He,t)11C, respectively, at the incident energy of 35 MeV. Our results for 10C do not support 7Be+3He as a possible solution for the 7Li problem. Concerning 11C results, the data show no new resonances in the excitation energy region of interest and this excludes 7Be+4He reaction channel as an explanation for the 7Li deficit.Comment: Accepted for publication in Phys. Rev. C (Rapid Communication

TELMA Cross Experiment Guidelines

Cerulli, M., Pedemonte, B., Robotti, E. (eds.). Internal Report, R.I. 01/07, I.T.D. - C.N.R., GenovaThis document contains the guidelines developed by members of TELMA as a means for planning, conducting, and analysing a cross experiment aimed at contributing to the construction of a shared research perspective among TELMA teams . This is the product of the PhD students and young researchers that brought forward the whole activity. The actual experimental phase was proceeded by a reflective phase in which an agreement was achieved on what research questions to address during the experiment. On this basis the first version of the guidelines document was built, containing all the research questions to be addressed, but also the experimental plans for each team. This included the employed didactical functionalities of the considered ICT tools, indications of the experimental settings, and the methods of data collection and analysis. During the whole experimental phase, the document was constantly updated, and shared among the involved persons which were periodically required to compare the different activities and reflections brought forward by all the teams

Spectroscopy of 28^{28}Na: shell evolution toward the drip line

Excited states in $^{28}$Na have been studied using the $\beta$-decay of implanted $^{28}$Ne ions at GANIL/LISE as well as the in-beam $\gamma$-ray spectroscopy at the NSCL/S800 facility. New states of positive (J$^{\pi}$=3,4$^+$) and negative (J$^{\pi}$=1-5$^-$) parity are proposed. The former arise from the coupling between 0d$\_{5/2}$ protons and a 0d$\_{3/2}$ neutron, while the latter are due to couplings with 1p$\_{3/2}$ or 0f$\_{7/2}$ neutrons. While the relative energies between the J$^{\pi}$=1-4$^+$ states are well reproduced with the USDA interaction in the N=17 isotones, a progressive shift in the ground state binding energy (by about 500 keV) is observed between $^{26}$F and $^{30}$Al. This points to a possible change in the proton-neutron 0d$\_{5/2}$-0d$\_{3/2}$ effective interaction when moving from stability to the drip line. The presence of J$^{\pi}$=1-4$^-$ negative parity states around 1.5 MeV as well as of a candidate for a J$^{\pi}$=5$^-$ state around 2.5 MeV give further support to the collapse of the N=20 gap and to the inversion between the 0f$\_{7/2}$ and 1p$\_{3/2}$ levels below Z=12. These features are discussed in the framework of Shell Model and EDF calculations, leading to predicted negative parity states in the low energy spectra of the $^{26}$F and $^{25}$O nuclei.Comment: Exp\'erience GANIL/LISE et NSCL/S80