Groups Of Lines Research Articles

Elementary band co-representations for (double)-grey line groups

Full sets of inequivalent elementary band co-representations (coEBRs) for spinless and spinful systems with grey line group (LG) symmetry are calculated and, together with recently reported elementary band representation (EBRs) for colorless single and double LGs by Milošević et al (2020 J. Phys. A: Math. Theor. 53 455204), the task of characterization of nonmagnetic quasi-one-dimensional (quasi-1D) topological crystals by means of the theory of topological quantum chemistry can be completed. Effects of additional time reversal symmetry on band topology and applicability of topological quantum chemistry is thoroughly analyzed. The main conclusions of the latter are illustrated on spinful Su–Schrieffer–Heeger model (topological mirror chain). Technique of induction and decomposition of coEBRs is fully developed and presented in detail. Complete sets of coEBRs for all thirteen families of single and double grey LGs are tabulated. Quasi-1D structures with symmetry enforced hourglass fermions are singled out.

Influence of heat and moisture supply on the manifestation of breeding- valuable quantitative traits of courgette lines

Introduction. One of the priorities of modern courgette breeding is the creation of F1 varieties and hybrids that combine high productivity and resistance to abiotic growing factors. Purpose. The goal is to investigate the correlation between the level of manifestation of quantitative traits and the hydrothermal coefficient (HTC) in selectively valuable courgette lines and to identify promising forms with a low dependence on climatic growing conditions. Methods. Breeding work was carried out with 20 lines of courgette of foreign origin. The correlation relationship was determined between the HTC and traits that are structural components of yield and determine the phenological phases of plant development. Results. 3 perspective lines were obtained (LK 17-11, RVL-19, VL-91), in which there was an average correlation between the HTC and the duration of the fruiting period (rp = 0.37…0.45). A group of lines (LK 17-42, LK 17-44, LK 17-47) was identified, in which, in terms of yield and productivity of plants, an average and moderate correlation with the HTC was observed (rp = 0.3…0.70). One line stood out, LK-17-11, which had weak correlations with the HTC for three important quantitative traits - “Total yield”, “Fruiting yield”, “Total productivity of one plant” (rp = 0.12…0.14).

Elementary band representations for (double)-line groups

Quantized topological invariants characterizing topological phases in quasi-1D materials are usually considered only on the basis of spatial inversion parity eigenvalues. However, symmetry of quasi-1D systems is far more complex and their complete topological characterisation can be obtained only on the basis of elementary band representations (EBRs) for the relevant symmetry groups. We derive complete sets of inequivalent EBRs for line groups (LG), the symmetry groups of all quasi-1D systems with either translational or helical periodicity. Besides, we determine also EBRs for double-LGs, accounting for spin degree of freedom. In order to illustrate applicability of the results obtained, we analyze electronic-band topology of a chiral single-wall carbon nanotube, using EBRs for relevant (double)-LG and discuss Su-Schrieffer–Heeger model from EBR-perspective.

LINEのグループトークにおけるネガティブ感情の発生のタイミング:LINEの「友だち」及び「グループ」の数との関係

LINEのグループトークにおけるネガティブ感情の発生のタイミング:LINEの「友だち」及び「グループ」の数との関係

Characterisation and diversity of Pyrenophora teres f. maculata isolates in Western Australia

Spot type net blotch caused by Pyrenophora teres f. maculata (Ptm) has become a prominent disease in Western Australia, as has also occurred elsewhere. The disease has a negative impact on both grain yield and quality resulting from reduced grain size. Lack of resistance and stubble retention are the likely factors in the increased severity of the disease in barley growing areas of Western Australia. Because of the increasing importance of spot type net blotch and the need to improve barley resistance, understanding pathogen virulence is a high priority as this has direct impact on the identification and utilization of resistance genes in breeding programs. Ninety nine isolates of Ptm were collected from geographically dispersed barley fields of Western Australia during 2001 and 2002. Forty nine sporulating isolates of Ptm were classified into seven isolate groups (IGs) on the basis of their infection responses on 26 differential barley lines. The 26 lines were likewise classified into four line groups (LGs) based on their distinguishing response to the spot type net blotch isolates. The varied infection responses among the differential barley lines demonstrated a wide geographic dispersal of IGs as well as previously undetected virulence in Ptm in Western Australia. The commercially grown barley cultivars Baudin and Gairdner are regarded as susceptible to spot type net blotch, but showed a range of reactions to the various Ptm isolates as seedling plants. The variability in the pathogen and the resistance identified in some genotypes used in this study are being investigated further to develop superior, adapted germplasm for use in barley breeding programs in Australia.

High temperature superconducting slow-wave coplanar transmission lines with normal-metal crossbars

A novel superconducting slow-wave transmission line has been prepared by overlaying a superconducting coplanar waveguide with normal metal crossbars. The crossbars increase the energy storage along the transmission line, reducing the line's group velocity allowing for shorter delay lines. Additionally, the cross-sectional dimensions of the line are smaller than typical transmission line structures, allowing for a further reduction of delay line size. Measurements show a group velocity of about 0.12 the speed of light with low dispersion, a 25 /spl Omega/ characteristic impedance, and moderate transmission loss. Because the group velocity is largely independent of any properties of the superconductor, these transmission lines exhibit excellent temperature stability and delay reproducibility.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>