4,510 research outputs found
Field-dependent quantum nucleation of antiferromagnetic bubbles
The phenomenon of quantum nucleation is studied in a nanometer-scale
antiferromagnet with biaxial symmetry in the presence of a magnetic field at an
arbitrary angle. Within the instanton approach, we calculate the dependence of
the rate of quantum nucleation and the crossover temperature on the orientation
and strength of the field for bulk solids and two-dimensional films of
antiferromagnets, respectively. Our results show that the rate of quantum
nucleation and the crossover temperature from thermal-to-quantum transitions
depend on the orientation and strength of the field distinctly, which can be
tested with the use of existing experimental techniques.Comment: 21 pages, 5 figures, Final version and accepted by Eur. Phys. J
A reflective e-learning approach for reading, thinking, and behavioral engagement
One of the main goals of the English as a Foreign Language (EFL) course is to facilitate the development of learners’ reading comprehension and reflective skills in English, which can be developed with appropriate instruction. However, in EFL courses, many students are inactive in reflecting on their reading and are disengaged from learning. To fill this gap, a reflective reading-based e-learning approach was proposed to explore the impact of the suggested approach on reading comprehension, reflective thinking, and behavioral engagement. The study aimed to improve the comprehension of the student’s reading using the proposed reflective e-learning approach. The study employed a quasi-experimental design in which the experimental group used reflective reading-based e-learning (n = 51) and the control group used conventional e-learning (n = 50) for a total of 13 weeks of participation. The experiment was designed to examine reading comprehension, reflective thinking, and behavioral engagement (e.g., reading time, Marker list, Quiz score, Memo list). The results revealed that the reflective reading-based e-learning approach could improve the comprehension and reflective thinking of the learners and promote behavioral engagement. These findings can be valuable for educators designing strategies to improve students’ reading comprehension skills and stimulate behavioral engagement in e-learning systems
4-Chloro-N′-(2-hydroxy-4-methoxybenzylidene)benzohydrazide methanol monosolvate
The title compound, C15H13ClN2O3·CH3OH, was synthesized by the condensation reaction of 2-hydroxy-4-methoxybenzaldehyde with 4-chlorobenzohydrazide in methanol. The Schiff base molecule displays a trans configuration with respect to the C=N and C—N bonds. The dihedral angle between the two benzene rings is 5.3 (2)°. In the crystal, molecules are linked by N—H⋯O and O—H⋯O hydrogen-bond interactions into chains running parallel to the a axis. An intramolecular O—H⋯N hydrogen bond is observed
Experimental and Theoretical Studies on Formability of 22MnB5 at Elevated Temperatures by Gleeble Simulator
AbstractThis paper, which includes an experimental analysis and theoretical predictions, presents a method to investigate the formability of high strength steel sheet 22MnB5 at elevated temperatures. In this method, two designs for tensile test specimens with laser engraving grids are developed and used to obtain the strain paths of a uniaxial tensile state and the plane strain occurring at elevated temperatures using a Gleeble simulator. On the other hand, a modified Cockcroft criterion that takes strain path into consideration is employed to predict the entire forming limit diagram. A forming limit diagram could be established as a result of using the modified Cockcroft criterion together with the limit strains obtained from the tensile tests based on two novel specimen designs. In this paper, forming limit diagrams at three strain rates and forming limit diagrams at temperatures ranging from 650 oC to 850 oC were established
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