Thermal Mass Spectra of Scalar and Pseudo-Scalar Mesons in IR-improved Soft-Wall AdS/QCD Model with Finite Chemical Potential

The thermal mass spectra of scalar and pseudo scalar mesons are studied in an IR-improved soft-wall AdS/QCD model. The Reissner-Nordstrom AdS black hole metric is introduced to describe both the finite temperature and density effects. The thermal spectral function is computed, which shows that the position of peak moves towards a smaller value and the width of peak also broadens to a larger value as the temperature increases. The critical temperature at which the peaks are completely dissolved has been found to be around T_{c}\simeq 160\sim 200\MeV. The effect of chemical potential is shown to be the same as the one caused by the temperature. It is found that when the temperature approaches to zero $T\approx 0$, the melting down of mesons occurs at the scaled critical chemical potential \mu_0/\kappa\approx 2.2\sim 2.4 \GeV.Comment: 13 pages, 4 figure

Infrared-Improved Soft-wall AdS/QCD Model for Mesons

We construct and investigate an infrared-improved soft-wall AdS/QCD model for mesons. Both linear confinement and chiral symmetry breaking of low energy QCD are well characterized in such an infrared-improved soft-wall AdS/QCD model. The model enables us to obtain a more consistent numerical prediction for the mass spectra of resonance scalar, pseudoscalar, vector and axial-vector mesons. In particular, the predicted mass for the lightest ground state scalar meson shows a good agreement with the experimental data. The model also provides a remarkable check for the Gell-Mann-Oakes-Renner relation and a sensible result for the space-like pion form factor.Comment: 15 pages, 4 figures, 7 tables, published versio

A closer look at interacting dark energy with statefinder hierarchy and growth rate of structure

We investigate the interacting dark energy models by using the diagnostics of statefinder hierarchy and growth rate of structure. We wish to explore the deviations from $\Lambda$CDM and to differentiate possible degeneracies in the interacting dark energy models with the geometrical and structure growth diagnostics. We consider two interacting forms for the models, i.e., $Q_1=\beta H\rho_c$ and $Q_2=\beta H\rho_{de}$, with $\beta$ being the dimensionless coupling parameter. Our focus is the I$\Lambda$CDM model that is a one-parameter extension to $\Lambda$CDM by considering a direct coupling between the vacuum energy ($\Lambda$) and cold dark matter (CDM), with the only additional parameter $\beta$. But we begin with a more general case by considering the I$w$CDM model in which dark energy has a constant $w$ (equation-of-state parameter). For calculating the growth rate of structure, we employ the "parametrized post-Friedmann" theoretical framework for interacting dark energy to numerically obtain the $\epsilon(z)$ values for the models. We show that in both geometrical and structural diagnostics the impact of $w$ is much stronger than that of $\beta$ in the I$w$CDM model. We thus wish to have a closer look at the I$\Lambda$CDM model by combining the geometrical and structural diagnostics. We find that the evolutionary trajectories in the $S^{(1)}_3$--$\epsilon$ plane exhibit distinctive features and the departures from $\Lambda$CDM could be well evaluated, theoretically, indicating that the composite null diagnostic $\{S^{(1)}_3, \epsilon\}$ is a promising tool for investigating the interacting dark energy models.Comment: 17 pages, 4 figures; accepted for publication in JCA

Surgical treatment of neuropathic pain

Neuropathic pain (NP) is a transient dysfunction caused by the damage of peripheral nerve and central nervous system, characterized with hyperalgesia, allodynia and spontaneous pain. Surgical treatment of neuropathic pain has experienced a long process, and plays an important role. This paper reviews recent documents of surgical techniques in the treatment of neuropathic pain. There are three kinds of surgical techniques: neuromodulation, microsurgical lesions and nerve decompression

What do seller manipulations of online product reviews mean to consumers?

There is growing evidence that consumers are influenced by online product reviews when making a variety of purchase decisions. Firms are therefore tempted to monitor and manipulate online product reviews on the company\u27s website or forum to influence consumer perceptions by anonymously posting positive reviews, hiding or deleting unfavorable reviews, or offering rewards to consumers who post favorable reviews. Our review of the literature has revealed a surprising shortage of work directed at the development of an integrative theoretical framework or rigorous empirical studies on the effectiveness and the exact impact of such activities on the payoffs to various parties. This study fills a void in the online marketing and information manipulation literature by studying consumers\u27 suspicion, awareness and evaluation of specific manipulation tactics through in-depth interviews with 16 experienced online shoppers in China. We adopt a grounded theory approach to analyze the qualitative data and end up with a series of research propositions (research framework) for further testing and verification. The findings about consumers\u27 views of online manipulations would provide valuable insights to industry associations and policy makers on whether and how to regulate online manipulation activities to ensure the healthy development of the e-commerce

Compression Behaviour of Natural and Reconstituted Clays

International audienceThe intercept of the log(1+e) - logσv' straight line is introduced to describe the effect of the starting point on the compressibility of natural and reconstituted clays. It is found that when the effective stress exceeds the remoulded yield stress, the compression behaviour of reconstituted clays is controlled solely by the water content at the remoulded yield stress and the liquid limit. Comparison of the compression behaviour of natural and reconstituted clays indicates that their difference in compressibility is caused by soil structure and the difference in water content at the compression starting point. The compression behaviour of natural clays can be classified into three regimes: 1) the pre-yield regime characterised by small compressibility with soil structure restraining the deformation up to the consolidation yield stress; 2) the transitional regime characterised by a gradual loss of soil structure when the effective stress is between the consolidation yield stress and the transitional stress; and 3) the post-transitional regime characterised by the same change law in compression behaviour as reconstituted clays when the effective stress is higher than the transitional stress. For the investigated clays, the transitional stress is 1.0-3.5 times the consolidation yield stress. The compression index varies solely with the void ratio at an effective stress of 1.0 kPa for both natural clays in post-transitional regime and reconstituted clays when the effective stress exceeds the remoulded yield stress, and when compressed in such cases the compression curves of both natural clays and reconstituted clays can be normalised well to a unique line using the void index