Measurements consisting of γ-ray excitation functions and angular distributions have been performed using the (n, n ′ γ) reaction on 62 Ni. The excitation function data allowed us to check the consistency of the placement of transitions in the level scheme. From γ-ray angular distributions, the lifetimes of levels up to ∼ 3.8 MeV in excitation energy have been extracted with the Doppler-shift attenuation method. The experimentally deduced values of reduced transition probabilities have been compared with the predictions of the quadrupole vibrator model and with large-scale shell model calculations in the f p shell configuration space. Two-phonon states have been found to exist with some notable deviation from the predictions of the quadrupole vibrator model, but no evidence for the existence of three-phonon states could be established. Z = 28 proton core excitations play a major role in understanding the observed structure.
Low-lying multiphonon states in 136 Ba have been populated with the inelastic neutron scattering reaction. Excitation functions were performed at neutron energies from 2.2 to 3.9 MeV, and γ -ray angular distributions were measured at 2.5, 3.0, and 3.5 MeV. Lifetimes have been determined using the Doppler-shift attenuation method, and electromagnetic transition rates have been deduced. The previously assigned 2 + 1,ms mixed-symmetry state at 2128.9 keV has been confirmed and is not greatly fragmented. For the first time in the N = 80 isotones, a 3 + 2,ms two-phonon mixed-symmetry state is proposed. In addition, the 2 + 5 and the 4 + 3 levels at 2222.7 and 2356.4 keV, respectively, decay with large B(M1) values to the two-phonon 2 + 2 and 4 + 1 states, respectively, which suggests two-phonon mixed-symmetric character. Their excitation energies, however, are not consistent with this interpretation.
The purpose of the present explanatory mixed‐method design is to examine the effectiveness of a developmental intervention, Embedded Metacognitive Prompts based on Nature of Science (EMPNOS) to teach the nature of science using metacognitive prompts embedded in an inquiry unit. Eighty‐three (N = 83) eighth‐grade students from four classrooms were randomly assigned to an experimental and a comparison group. All participants were asked to respond to a number of tests (content and nature of science knowledge) and surveys (metacognition and self‐regulatory efficacy). Participants were also interviewed. It was hypothesized that the experimental group would outperform the comparison group in all measures. Partial support for the hypotheses was found. Specifically, results showed significant gains in content knowledge and nature of science knowledge of the experimental group over the comparison group. Qualitative findings revealed that students in the comparison group reported scientific thinking in similar terms as the scientific method, while the experimental group reported that scientists were creative and had to explain events using evidence, which is more closely aligned to the aspects of the nature of science. EMPNOS may have implications as a useful classroom tool in guiding students to check their thinking for alignment to the nature of science.
Based on results from a measurement of weak decay branches observed following the β- decay of 94Y and on lifetime data from a study of 94Zr by inelastic neutron scattering, collective structure is deduced in the closed-subshell nucleus 94Zr. These results establish shape coexistence in 94Zr. The role of subshells for nuclear collectivity is suggested to be important.
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