Temperature sensitivity of Nd³⁺, Yb³⁺:YF<inf>3</inf> ratiometric luminescent thermometers at different Yb³⁺ concentration

Nd3+ (0.5 mol.%), Yb3+ (1.0, 2.0, 3.0, 4.0, and 8.0 mol.%):YF3 phosphors were synthesized using a co-precipitation method with subsequent hydrothermal treatment and annealing in vacuum. The Nd3+, Yb3+:YF3 phosphors are orthorhombic phase nano-crystals. Luminescence intensity ratio (LIR) of Nd3+ (4F3/2 – 4I9/2, ~866 nm) and Yb3+ (2F5/2 – 2F7/2, ~980 nm) emissions was chosen as temperature-dependent parameter. The energy exchange between 4F3/2 (Nd3+) and 2F5/2 (Yb3+) is phonon-assisted which explains the temperature dependence of LIR. There are Nd3+ to Yb3+ energy transfer (ET), Yb3+ to Nd3+ back energy transfer (BET) and energy diffusion (ED) between Yb3+ ions. The probability of BET decreases with the increase of Yb3+ concentration which leads to LIR dependence on Yb3+ concentration. The maximum absolute temperature sensitivity (Sa) was achieved for Nd3+ (0.5%), Yb3+ (1.0%):YF3 (Sa = 0.0018 K−1 at 148 K). The studied samples demonstrate high stability after 8 cooling-heating cycles. The Nd3+ (0.5%), Yb3+ (1.0%):YF3 phosphors are very promising for temperature sensing

Genomics of tolerance to abiotic stress in the Triticeae

Genomics platforms offer unprecedented opportunities to identify, select and in some cases clone the genes and the quantitative trait loci (QTLs) that govern the tolerance of Triticeae to abiotic stresses and, consequently, grain yield. Transcriptome profiling and the other \u201comics\u201d platforms provide further information to unravel gene functions and validate the role of candidate genes. This review provides a synopsis of the main results on the studies that have investigated the genomics of Triticeae crops under conditions of abiotic constraints. With their rich biodiversity and high functional plasticity in response to environmental stresses, Triticeae crops provide an ideal ground for taking full advantage of the opportunities offered by genomics approaches. Ultimately, the practical impact of the knowledge and materials generated through genomics-based approaches will depend on their integration and exploitation within the extant breeding programs