Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training

The protection of human health and the preservation of the environment are topics that form anintegral part of the primary school curriculum in Serbia. However, research studies have shown thatstudents do not have enough knowledge to contribute to the development of a healthy lifestyle andenvironmental awareness. The latest changes in school policy and curricula confirm that the relevanceof environmental education has been recognized, but changes in school practice are yet to come. Thisarticle discusses the challenges encountered in the implementation of the intended curriculum andoffers suggestions for changes to the curriculum, pedagogy, and teacher training in order to enhanceenvironmental educationThis is the peer-reviewd version of the artivle: Stanišić, Jelena, и Slavica Maksić. 2014. „Environmental Education in Serbian Primary Schools: Challenges and Changes in Curriculum, Pedagogy, and Teacher Training“. Journal of Environmental Education 45(2):118–31. doi: 10.1080/00958964.2013.829019.Related to published version: [ http://ipir.ipisr.org.rs/handle/123456789/240

On the di-1-naphthylcarbene-dibenzofluorene rearrangement and the ethylenization of diarylcarbinols

Solution-spray flash vacuum thermolysis of di-1-naphthyldiazomethane (9) results in the formation of dibenzo[c,g]fluorene (12), formed via a carbene- carbene rearrangement of di-1-naphthylcarbene (10). The isomeric dibenzo[α,i]fluorene (11) claimed by Franzen and Joschek (Liebigs Ann. Chem. 1960, 633, 7) is not formed, and no dibenzofluorene is formed on thermolysis in boiling naphthalene. 11 is formed on dehydration of di-1-naphthylcarbinol (14) with phosphoric acid, but the claimed tetra-1-naphthylethylene (13) is not formed, and the so-called ethylenization of diarylcarbinols is cast in doubt generally. The compound previously believed to be 13 is 13-[di(1- naphthyl)methyl]-dibenzo[α,i]fluorene (22). The alleged cleavage of 13 into two molecules of carbene 10 is unsubstantiated

Superconductivity in Crystallographically Disordered LaHg_6.4

The influence of structural disorder on superconductivity is not yet fully understood. A concurrent examination of crystallographic and physical properties of LaHg6.4 reveals that this material enters a superconducting state below Tc = 2.4 K while showing crystallographic disorder in one dimension. Lanthanum mercuride, which crystallizes in a new structure type (space group Cmcm, a = 9.779(2) Å, b = 28.891(4) Å, c = 5.0012(8) Å, Z = 8), has remained out of reach for nearly 50 years. In this crystal structure, strong disorder is present in the channels that propagate along the [001] direction. By implementing a combination of cutting-edge synthesis and characterization techniques, we were able to circumvent the complexity associated with the low formation temperature and chemical reactivity of this substance and study the superconductivity of LaHg6.4 in detail. © 2022 The Authors. Published by American Chemical Society

Uranium-mercury complex antiferromagnet: UHg_6.4

Crystallographically complex compounds containing 4f and 5f electrons often have peculiar chemical and physical properties. In this work we present discovery and characterization of a new material UHg6.4, located at the border to complex intermetallics. This material crystallizes in the LaHg6.4 structure type, which can be represented by La/U-centered polyhedra with coordination numbers of 13 and 14. Much like the LaHg6.4 analog, UHg6.4 shows strong crystallographic disorder, in particular for Hg atoms in the channels along [001]. The UHg6.4 compound orders antiferromagnetically below TN1=35.5±1K and displays another transition at TN2=47.3±1K, which is likely also antiferromagnetic. Both transitions are only slightly affected by magnetic field. Given high air sensitivity of UHg6.4, an exceptional experimental environment for sample synthesis and characterization was necessary in order to comprehensively describe the chemical and physical properties of this system. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society

Reorientational Motions and Ionic Conductivity in (NH4)2B10H10 and (NH4)2B12H12

We investigated molecular dynamics in two ammonium borane systems from the group of promising ion conductors. The investigation was performed by means of 1H and 11B NMR spectroscopy and spin-lattice relaxation techniques. We identified two reorientational processes, the rotations of NH4 units that are present already at low temperatures, and rotations of large boron cages, B10H10 or B12H12, which are thermally activated and become prominent above 250 K. Activation energies for these processes were determined. In addition, solid-state ion conductivity measurements were conducted to determine poor NH4 conductivity of both systems

Speromagnetism and asperomagnetism as the ground states of the Tb-Dy-Ho-Er-Tm “ideal” high-entropy alloy

We address the nature of the collective magnetic state in an ideal high-entropy alloy (HEA), representing a magnetically concentrated system with all lattice sites occupied by localized magnetic moments and containing randomness and frustration due to chemical disorder. Being a “metallic glass on a topologically ordered lattice”, HEAs possess simultaneously the properties of an ordered crystal and an amorphous glass. The influence of this crystal-glass duality on the collective magnetic state was studied experimentally on a hexagonal Tb-Dy-Ho-Er-Tm (TDHET) HEA, composed of rare-earth (RE) elements with zero pair mixing enthalpies that assure completely random mixing of the elements and very similar atomic radii that minimize lattice distortions, representing a prototype of an ideal HEA. The TDHET HEA is characterized by probability distributions of the atomic moments , the exchange interactions , the magnetocrystalline anisotropy , and the dipolar interactions . Based on the measurements of the static and dynamic magnetization, the magnetization curves, the thermoremanent magnetization, the specific heat and the magnetoresistance, we found that the collective magnetic state of the TDHET is temperature-dependent, forming a speromagnetic (SPM) state in the temperature range between about 140 and 30 K and an asperomagnetic (ASPM) state below 20 K. In the intermediate temperature range between 30 and 20 K, a spin glass (SG) state is formed, representing a transition state between the speromagnetic and asperomagnetic states. The observed temperature evolution of the magnetic ground state in the TDHET HEA upon cooling in the sequence SPM→SG→ASPM is a result of temperature-dependent, competing magnetic interactions. The distribution of the exchange interactions shifts continuously on the axis from the high-temperature SPM-type with the average interaction biased towards a net negative value, , through the SG-type with , to the low-temperature ASPM-type with . This shift is a band-structure effect, closely linked with the crystallinity of the spin system, which the TDHET HEA shares with the topologically ordered crystals. The probability distributions , , and are, on the other hand, a consequence of chemical disorder, a property that the TDHET HEA shares with the amorphous magnets. Both features, the topologically ordered lattice and the amorphous-type chemical disorder essentially determine the magnetic state of an ideal, RE-based HEA

Be₃Ru: Polar Multiatomic Bonding in the Closest Packing of Atoms

Abstract The new phase Be3Ru crystallizes with TiCu3-type structure (space group Pmmn (59), a=3.7062(1)?Å, b=4.5353(1)?Å, c=4.4170(1)?Å), a coloring variant of the hexagonal closest packing (hcp) of spheres. The electronic structure revealed that Be3Ru has a pseudo-gap close to the Fermi level. A strong charge transfer from Be to Ru was observed from the analysis of electron density within the Quantum Theory of Atoms in Molecules (QTAIM) framework and polar three- and four-atomic Be?Ru bonds were observed from the ELI?D (electron localizability indicator) analysis. This situation is very similar to the recently investigated Be5Pt and Be21Pt5 compounds. The unusual crystal chemical feature of Be3Ru is that different charged species belong to the same closest packing, contrary to typical inorganic compounds, where the cationic components are located in the voids of the closest packing formed by anions. Be3Ru is a diamagnet displaying metallic electrical resistivity