Characteristic length of a Holographic Superconductor with dd-wave gap

After the discovery of the $s$-wave and $p$-wave holographic superconductors, holographic models of $d$-wave superconductor have also been constructed recently. We study analytically the perturbation of the dual gravity theory to calculate the superconducting coherence length $\xi$ of the $d$-wave holographic superconductor near the superconducting phase transition point. The superconducting coherence length $\xi$ divergents as $(1-T/T_c)^{-1/2}$ near the critical temperature $T_c$. We also obtain the magnetic penetration depth $\lambda\propto(T_c-T)^{-1/2}$ by adding a small external homogeneous magnetic field. The results agree with the $s$-wave and $p$-wave models, which are also the same as the Ginzburg-Landau theory.Comment: last version, 10 pages, accepted by PR

Differential measurement of atmospheric refraction with a telescope with double fields of view

For the sake of complete theoretical research of atmospheric refraction, the atmospheric refraction under the condition of lower angles of elevation is still worthy to be analyzed and explored. In some engineering applications, the objects with larger zenith distance must be observed sometimes. Carrying out observational research of the atmospheric refraction at lower angles of elevation has an important significance. It has been considered difficult to measure the atmospheric refraction at lower angles of elevation. A new idea for determining atmospheric refraction by utilizing differential measurement with double fields of view is proposed. Taking the observational principle of HIPPARCOS satellite as a reference, a schematic prototype with double fields of view was developed. In August of 2013, experimental observations were carried out and the atmospheric refractions at lower angles of elevation can be obtained by the schematic prototype. The measured value of the atmospheric refraction at the zenith distance of 78.8 degree is $240.23"\pm0.27"$, and the feasibility of differential measurement of atmospheric refraction with double fields of view was justified. The limitations of the schematic prototype such as inadequate ability of gathering light, lack of accurate meteorological data recording and lower automatic level of observation and data processing were also pointed out, which need to be improved in subsequent work.Comment: 10 pages, 6 figure

Locate QCD Critical End Point in a Continuum Model Study

With a modified chemical potential dependent effective model for the gluon propagator, we try to locate the critical end point (CEP) of strongly interacting matter in the framework of Dyson-Schwinger equations (DSE). Beyond the chiral limit, we find that Nambu solution and Wigner solution could coexist in some area. Using the CornwallJackiw-Tomboulis (CJT) effective action, we show that these two phases are connected by a first order phase transition. We then locate CEP as the end point of the first order phase transition line. Meanwhile, based on CJT effective action, we give a direct calculation for the chiral susceptibility and thereby study the crossover.Comment: 9 pages, 7 figures; Version published in JHE

Fabric-evoked prickle of fabrics made from single fibres using axial fibre-compression-bending analyzer

Fabrics made from cotton, cashmere, flax, hemp, ramie, jute, and wool fibres, have been used to investigate and analyze the prickle comfort properties of fabrics worn as garments. Physical properties include single-fibre critical load, compression and bending modules, which greatly affect the fabric physiological comfort. The fibres are tested using a ‘fibre axial compression-bending analyzer’. The behavior mechanisms of single-needle fibre are also analyzed, evaluated, and explained using fibres critical load, fineness, and protruding length. Physical and neuro-physiological basis for prickle sensation force from single-needle fibre depends on its bending modulus and axial compressive behavior. This experimental work shows that the bending modulus of ramie, jute, and wool fibre is significantly high as compared to other fibres. Thus, high prickle values of ramie, jute and wool fibres make them more uncomfortable due to the cross-section parameters and bending modulus of the single fibre needle. It is observed that the prickle feeling comes from the axial-compressive behavior and the number of effective fibre needles protruding from worn fabric surface. Therefore, prickle sensation aroused during skin–fabric contact is mostly related to the fibre and surface roughness characteristics of fabrics, and the effect of the fabric material on prickle is found to be more