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- Ducommun, Yves, et al.
(författare)
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1H NMR Kinetic Study of Dimethyl Sulfoxide Exchange on Tetrakis(dimethyl- sulfoxide)platinum(II) at Variable Temperature and Pressure : High-pressure NMR kinetics. 36.
- 1989
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 1520-510X .- 0020-1669. ; 28:2, s. 377-379
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Tidskriftsartikel (refereegranskat)abstract
- The present report is a 'H NMR investigation of the dimethyl sulfoxide exchange on Pt(Me2S0)42+ as a function of temperature and pressure in CD3N02. Dimethyl sulfoxide is an ambidentate ligand, and the complex contains two 0-bonded and two S-bonded ligands that are exchanging with the free ligand at different rates. It is favorable to follow these exchanges in a non-coordinating diluent like nitromethane, since it allows variation of the ligand concentration, thus giving an opportunity to establish the rate law. The use of a diluent of high dielectric constant and of uncharged ligands minimizes the electrostriction changes along the reaction path, so that the measured volumes of activation will reflect primarily the intrinsic changes of molecular volumes on going to the transition state.
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| 3. |
- Gunnarsson, Robert, 1972-, et al.
(författare)
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Secondary school science teachers’ arguments for the particulate nature of matter
- 2018
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Ingår i: Journal of Research in Science Teaching. - : John Wiley & Sons. - 0022-4308 .- 1098-2736. ; 55:4, s. 503-525
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Tidskriftsartikel (refereegranskat)abstract
- How do secondary school science teachers justify the model of a particulate nature of matter, and how do the arguments they use relate to historical arguments? To find out, we individually interviewed 11 in-service secondary school science teachers (certified to teach chemistry and/or physics in secondary school, and with 2–30 years of teaching experience) regarding their arguments for the particulate nature of matter and experiments that could demonstrate the existence of particles. The collected data were qualitatively analyzed. Three qualitatively different categories of arguments could be constructed from data: philosophical arguments, indirect experimental arguments, and direct experimental arguments. The indirect experimental arguments, which is the largest category, could be further divided into qualitatively different subcategories: non-specific research and experiments, and chemical, physical and subatomic experiments. Even though several experiments and arguments were suggested by the informants in our study, the arguments regarding the validity of the experiments were quite uncertain and vague. The experiments and arguments were used to corroborate the particulate nature of matter and taken for granted in advance rather than used to justify a model with particles. The outcome was discussed in relation to scientific arguments and experiments and in view of results from previous science education research. Based on our data, teacher education and in-service teacher training, as well as teacher guides, were suggested to be more elaborate regarding contemporary knowledge, with direct experimental evidence for the particulate nature of matter being presented.
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| 4. |
- Hellquist, Björn
(författare)
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En kemists synpunkter på matlagning och födointag
- 1996
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Ingår i: Vad är kunskap, kvalitet och kompetens?. - Jönköping : Högsk. för lärarutbildning & kommunikation (HLK). ; , s. 153-165
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Hellquist, Björn, et al.
(författare)
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Geometrins ställning i den svenska skolan
- 2000
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Ingår i: Den reflekterande medborgaren. - Jönköping : Jönköping University Press. - 9197312061 ; , s. 217-230
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Bokkapitel (populärvet., debatt m.m.)
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| 13. |
- Hellquist, Björn, et al.
(författare)
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Structures of Solvated Cations of Palladium(II) and Platinum(II) in Dimethyl Sulfoxide, Acetonitrile and Aqueous Solution Studied by EXAFS and LAXS
- 1991
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Ingår i: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X. ; 45:5, s. 449-455
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Tidskriftsartikel (refereegranskat)abstract
- X-Ray absorption edge and EXAFS spectra of the solvated cations of platinum(II) in water, dimethyl sulfoxide and acetonitrile and of palladium(II) in dimethyl sulfoxide have been recorded and analyzed. The cations are four-coordinated. Pt-O in Pt(H2O)4(2+) is 2.01(1) angstrom and Pt-N in Pt(CH3CN)4(2+) is 2.00(1) angstrom. The dimethyl sulfoxide solvated cations of both platinum and palladium contain two sulfur- and two oxygen-bonded ligands with Pt-O 2.07(2), Pt-S 2.21(2), Pd-O 2.04(2), and Pd-S 2.23(2) angstrom, probably in a square-planar cis-arrangement, as in the solid state. Large-angle X-ray scattering (LAXS) studies of the platinum(II) dimethyl sulfoxide solvated cation in a solution of the triflate salt gave Pt-O 2.07(1) and Pt-S 2.20(1) angstrom and in a solution of the tetrafluoroborate salt Pt-O 2.07(2) and Pt-S 2.21(5) angstrom, in good agreement with the EXAFS results. Neither technique gave any support for axially bound solvent molecules in addition to the four in the assumed square coordination plane.
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| 15. |
- Runesson Kempe, Ulla, 1952-, et al.
(författare)
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Beyond the borders of the local : How “instructional products” from learning study can be shared and enhance student learning
- 2018
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Ingår i: International Journal for Lesson and Learning Studies. - : Emerald Group Publishing Limited. - 2046-8253 .- 2046-8261. ; 7:2, s. 111-123
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this paper is to present how experiences gained from a theory-informed lesson study – learning study (LrS) – in regard to a specific learning goal can be shared and used by other teachers in new contexts.Design/methodology/approach: A group of teachers worked together in a cyclic, iterative process of planning, evaluating and revising teaching. The aim was to provide possibilities for grade 2 and 3 students to become familiar with negative numbers. The teacher group came to the conclusion that the students needed to be able to differentiate some aspects of negative numbers. The conjecture was put to the test in a follow-up study (FS) with five new teachers and eight classes. One lesson was taught based on the empirical findings in the LrS.Findings: The results suggest that teachers’ collaborative work has possibilities to produce knowledge about critical aspects of learning that can be communicated and adopted in new contexts. The teachers in the FS were able to make sense of the results from LrS and incorporate the critical aspects in their teaching in a way that enhanced students’ learning.Originality/value: It is demonstrated that teacher collaboration in LrS can create knowledge that goes beyond the border of the local context.
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| 16. |
- Runesson, Ulla, et al.
(författare)
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Beyond the borders of the local : How “instructional products” from learning study can be shared and enhance student learning
- 2018
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Ingår i: International Journal for Lesson and Learning Studies. - : Emerald Group Publishing Limited. - 2046-8253 .- 2046-8261. ; 7:2, s. 111-123
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – The purpose of this paper is to present how experiences gained from a theory-informed lesson study – learning study (LrS) – in regard to a specific learning goal can be shared and used by other teachers in new contexts.Design/methodology/approach – A group of teachers worked together in a cyclic, iterative process of planning, evaluating and revising teaching. The aim was to provide possibilities for grade 2 and 3 students to become familiar with negative numbers. The teacher group came to the conclusion that the students needed to be able to differentiate some aspects of negative numbers. The conjecture was put to the test in a follow-up study(FS) with five new teachers and eight classes. One lesson was taught based on the empirical findings in the LrS.Findings – The results suggest that teachers’ collaborative work has possibilities to produce knowledge about critical aspects of learning that can be communicated and adopted in new contexts. The teachers in the FS were able to make sense of the results from LrS and incorporate the critical aspects in their teaching in away that enhanced students’ learning.Originality/value – It is demonstrated that teacher collaboration in LrS can create knowledge that goes beyond the border of the local context
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