Stabilita a změna osobních hodnot u lidí s různými trajektoriemi životní dráhy: longitudinální studie

Background. Previous research on the stability of personal values in the context of life transitions has usually focused on the presence of a single transition. However, life transitions in everyday life occur simultaneously with other life transitions. The aim of this longitudinal study was therefore to identify different trajectories of life transitions in young adults and to compare the stability of their personal values. Method. In the first wave of research, participants were 18-33 years old; in the second wave, they were 29-43 years old (N = 632; 392 women). In both waves, they completed Schwartzʼs Portrait Value Questionnaires (PVQ); in the second wave, they completed the Life History Calendar focusing on the presence of entry into life transitions. Results. Latent class analysis revealed two trajectories: Experienced transitions (people who experienced all observed transitions) and Partially experienced transitions (people who experienced only entry into regular employment and part of them entered cohabitation). Differential stability of personal values occurred in both trajectories. The differences in the stability of values found between the individual trajectories were insignificant, except for personal values universalism and tradition. Although before entry into life transitions, personal values were not significant predictors of belonging to a particular trajectory, after their experiencing people with the Experienced transitions trajectory more often reached lower levels of values associated with openness to change.

Tuning The Properties of Ba-M Hexaferrite BaFe11.5Co0.5O19: A Road Towards Diverse Applications

The development of hexaferrite nanoparticles is scrutinized as potential sorbents for the removal of chromium (Cr) ions from aqueous chromium-containing solutions in a batch adsorption experiment. The transition metal Co doped BaFe12O19 hexaferrite compounds (BHF) have been synthesized successfully via citrate auto combustion technique. Structural, morphological, and magnetic properties are testified. X-ray diffraction pattern ratifies the existence of hexagonal phase as a main phase for the prepared samples. The average crystallite sizes are found in the range of 47–49 nm. The high-resolution transmission electron microscopy (HRTEM), as well as the Fourier, transform infrared spectrophotometry results confirm an M-type hexagonal structure existing. The c-T indicates the temperature-dependent ferromagnetic behavior of BHF nanoparticles. The derivative shows a single transition temperature Tc at 698 °C, 710 for BHF and BHCF respectively. The prepared samples are utilized as an adsorbent for the removal of Cr (VI) from the aqueous solution. The maximum adsorption capacity (qm) of Cr (VI) on the nano hexaferrite is higher than that of various other adsorbents testified in the literature. The pseudo-second-order kinetic model gives a better fit to the experimental data

Theoretical Inspection of TM-P4C Single-Atom Electrocatalyst: Ultra-High Performance for bifunctional Oxygen Reduction and Evolution Reactions

Developing the cost-effective or even bifunctional electrocatalysts for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) with industrially relevant activity is highly desired for metal-air batteries at the current stage. Herein, in this work, the catalytic performances of the single transition metal (TM) atom embeds graphene sheet with the tetra-coordinates Phosphorus (TMP4) for ORR and OER were investigated based on the density functional theory method. The results demonstrate that the most promising ORR and OER catalytic activity can achieved on the CoP4 with the smallest potential gap ∆E and the lowest overpotentials of 0.37 and 0.32 eV among all TMP4 systems, respectively, and the catalytic activity is even better than that of the traditional Pt and IrO2 catalysts. Furthermore, the AIMD calculation was conducted to confirm the thermodynamics stability of CoP4. This work screens out promising candidates for novel graphene-based bifunctional ORR and OER catalysts and provides the theoretical guidance for the development of single-atom catalysts.

Linking Bi-Metal Distribution Patterns in Porous Carbon Nitride Fullerene to Its Catalytic Activity toward Gas Adsorption

Immobilization of two single transition metal (TM) atoms on a substrate host opens numerous possibilities for catalyst design. If the substrate contains more than one vacancy site, the combination of TMs along with their distribution patterns becomes a design parameter potentially complementary to the substrate itself and the bi-metal composition. By means of DFT calculations, we modeled three dissimilar bi-metal atoms (Ti, Mn, and Cu) doped into the six porphyrin-like cavities of porous C24N24 fullerene, considering different bi-metal distribution patterns for each binary complex, viz. TixCuz@C24N24, TixMny@C24N24, and MnyCuz@C24N24 (with x, y, z = 0–6). We elucidate whether controlling the distribution of bi-metal atoms into the C24N24 cavities can alter their catalytic activity toward CO2, NO2, H2, and N2 gas capture. Interestingly, Ti2Mn4@C24N24 and Ti2Cu4@C24N24 complexes showed the highest activity and selectively toward gas capture. Our findings provide useful information for further design of novel few-atom carbon-nitride-based catalysts.