Pseudospin induced chirality with Staggered Optical Graphene

Pseudospin plays a very important role in understanding various interesting physical phenomena associated with 2D materials such as graphene. It has been proposed that pseudospin is directly related to angular momentum, and it was recently experimentally demonstrated that orbit angular momentum is an intrinsic property of pseudospin in a photonic honeycomb lattice. However, in photonics, the interaction between spin and pseudospin for light has never been investigated. In this Letter, we propose that, in an optical analogue of staggered graphene, i.e. a photonic honeycomb lattice waveguide with in-plane inversion symmetry breaking, the pseudospin mode can strongly couple to the spin of an optical beam incident along certain directions. The spin-pseudospin coupling, caused by the spin-orbit conversion in the scattering process, induces a strong optical chiral effect for the transmitted optical beam. Spin-pseudospin coupling of light opens door to the design of pseudospin-mediated spin or valley selective photonic devices

含盐遗址重塑土的吸力测定及土水特征曲线拟合

Under the long-term impacts of influencing factors including water and soluble salts, the Site of Yarkhoto Ancient City which is a precious earthen heritage is subjected to irreversible deterioration. Exfoliation of surface crusts on the remaining walls is one of the commonly observed pathologies. The behaviors of unsaturated soils are dependent on suction, thus making it crucial to obtain reliable soil-water retention curve (SWRC) for investigating the deterioration mechanisms of earthen heritages. The slurries with different NaCl contents are prepared from the local soils. The total suction and matric suction during desiccation are determined using five methods (vapor equilibrium, water potentiometer, filter paper, pressure plate and high-capacity tensiometer), and the discrepancies are further discussed. Meanwhile, two models, i.e., van Genuchten (vG) and Fredlund & Xing (FX), are adopted to model the SWRC. The results show that NaCl has insignificant effect on the matric suction but induces osmotic suction, leading to a great increase in the total suction especially at high water contents. The general trend of water retention behavior of soils obtained by various methods is consistent. Based on the data obtained by different methods, the errors of curve fitting can be minimized, and a reliable SWRC on drying path is acquired in the full suction range. Both vG and FX models can model the experimental data well, which provides a scientific basis for further quantitative analysis of the evolution process of surface crusts cracking in earthen heritages

Description of a New Anguinid Nematode, Nothotylenchus phoenixae n. sp. (Nematoda: Anguinidae) Associated with Palm Date Trees and Its Phylogenetic Relations within the Family Anguinidae

Abstract: Nothotylenchus phoenixae n. sp. is described and illustrated from soil samples of palm trees in Kermanshah Province, western Iran. The new species is characterized by a body length of 784 (663 to 925) mmin females and 677 to 715 mmin males; a delicate stylet 6 (5 to 7) mmlong and six lines in the lateral field; median bulb of pharynx fusiform, nonmuscular, and nonvalvate; isthmus elongate, slender ending to a pyriform basal pharyngeal bulb not overlapping intestine; postvulval uterine sac well developed, 15 (14 to 17) mm long, female tail elongate-conoid with pointed terminus; and male with adanal bursa and spicules 21 to 22 mm long (n = 2). The new species comes close in morphology and morphometrics to five known species of the genus, namely N. affinis, N. hexaglyphus, N. persicus, N. taylori, and N. uniformis. Molecular analyses of the partial 18S, D2/D3 expansion segments of the partial 28S and internal transcribed spacer (ITS) revealed this as a new species. The sequences of the partial 18S and 28S D2/D3 regions confirmed the close phylogenetic relationship between N. phoenixae n. sp. and other anguinids, but Nothotylenchus is clearly separated from Ditylenchus species and should be considered as a valid genus

Morphological and Molecular Characterization of \u3ci\u3eGracilacus wuae\u3c/i\u3e n. sp. (Nematoda: Criconematoidea) Associated with Cow Parsnip (\u3ci\u3eHeracleum maximum\u3c/i\u3e) in Ontario, Canada

Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 mmlong, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of the genital primordia. The third-stage juveniles are similar to females but smaller. Phylogenetic studies using the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer (ITS) sequences collectively provide evidence of a grouping with other Gracilacus and some species of Paratylenchus with stylet length of females longer than 41 mm deposited in GenBank

Morphological and Molecular Characterization of \u3ci\u3eGracilacus wuae\u3c/i\u3e n. sp. (Nematoda: Criconematoidea) Associated with Cow Parsnip (\u3ci\u3eHeracleum maximum\u3c/i\u3e) in Ontario, Canada

Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 mmlong, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of the genital primordia. The third-stage juveniles are similar to females but smaller. Phylogenetic studies using the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer (ITS) sequences collectively provide evidence of a grouping with other Gracilacus and some species of Paratylenchus with stylet length of females longer than 41 mm deposited in GenBank