Understanding how crystallographic strain orientation governs coupled structural, electronic, and thermoelectric responses of low-symmetry two-dimensional materials remains an open challenge. In particular, the strain-structure-property relationships in pentagonal transition-metal dichalcogenides have not been systematically clarified. In this work, we employ first-principles density functional theory combined with semiclassical Boltzmann transport analysis to investigate the effects of uniaxial strain applied along the in-plane x-and y-directions on PdS2 and PtS2 monolayers. Owing to their non-equivalent X-S bonding topology, strain applied along different directions activates distinct microscopic deformation pathways, with epsilon xxaccommodated predominantly through bond-length variation, whereas epsilon yy involves a greater contribution from bond-angle rearrangement and out-of-plane structural relaxation. At equilibrium, PdS2 and PtS2 exhibit band gaps of 2.13 eV and 3.00 eV, respectively, which decrease significantly under tensile strain, with reductions of up to 66.63% and 52.0%. Strain-dependent projected density-of-states analysis further reveals orientation-dependent changes in the energetic distribution and overlap of Pd/Pt-d and S-p states near the band edges, providing an orbital-level link between directional lattice deformation and electronic reconstruction. These electronic changes are reflected in the thermoelectric response, with the Seebeck coefficient and power exhibiting pronounced dependence on both strain magnitude and loading orientation for both p-type and n-type carriers. Comparative analysis reveals that PtS2 displays a more favorable thermoelectric response, while PdS2 shows enhanced sensitivity to strain orientation demonstrating complementary thermoelectric performance and strain tunability. The dynamical and thermal stability of representative highly strained configurations were further examined by phonon and ab initio molecular dynamics simulations. Overall, the results establish crystallographic strain orientation as an additional degree of freedom, beyond strain magnitude alone, for controlling coupled structural, electronic, and thermoelectric properties in low-symmetry two-dimensional materials.
Potentilla sensu lato, a taxonomically complex genus within the Rosaceae, comprises approximately 300 taxa worldwide. Thirteen taxa, each restricted to limited localities, are currently recognized as endemic to the Mongolian flora. Therefore, the conservation of Potentilla faces significant challenges due to habitat loss caused by climate change and overharvesting. In this study, we explore the phylogenetic relationships and local evolutionary patterns of five endemic Potentilla species in Mongolia based on their complete chloroplast genomes. We utilized high-throughput sequencing of complete chloroplast genomes and conducted comparative analyses. The complete chloroplast genomes ranged from 156,273 to 156,395 bp long and exhibited a typical quadripartite structure. Genome annotation revealed 113 unique genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Two intergenic regions (ndhF–rpl32 and rpl32–trnL) in the SSC region showed markedly high diversity among chloroplast genomes. Analysis of selection signatures identified two genes (rpoC1 and ycf1) under positive selection. These genes may play important roles in the adaptation of these species to specific geographical environments. Phylogenetic analysis placed all five newly sequenced species within the Argentea clade, and divergence time estimation indicated that diversification within this clade occurred from the late Miocene to the Pleistocene. This study provides valuable genomic resources for endemic Potentilla species in Mongolia, offers insights into their evolutionary history, and lays a foundation for future phylogenetic research and molecular marker development. Furthermore, this study fills a geographic gap in chloroplast genomes sampling of Potentilla in Central Asia.
Remittances play a crucial role in the economies of low- and middle-income countries (LMICs), yet the impact of their transfer costs on economic growth remains underexplored. This study addresses the urgent need to reduce remittance costs, as outlined in Sustainable Development Goal (SDG) 10c. We investigate how remittance transfer costs affect their contribution to economic growth across LMICs, distinguishing between high-cost and low-cost remittance-receiving countries. We propose a theoretical model from a neo-classical economic perspective, illustrating how remittance transfer costs negatively influence the flow of remittances. For empirical exploration of the relationship between remittances and economic growth, and implicit effect of transfer cost, we specify the growth equation within augmented Solow framework. Using a balanced panel dataset of 71 LMICs from 1996 to 2021, we estimate the relationship using three econometric techniques—the cross-sectionally augmented autoregressive distributed lag (CS-ARDL), the augmented mean group, and the common correlated effects mean group (CCEMG), procedures. For the full sample, which does not account for transfer costs, our findings reveal a positive but statistically insignificant effect of remittances on growth. When we categorize the countries based on whether remittance transfer costs are above or below 3
