(2+1)(2+1)-dimensional regular black holes with nonlinear electrodynamics sources

On the basis of two requirements: the avoidance of the curvature singularity and the Maxwell theory as the weak field limit of the nonlinear electrodynamics, we find two restricted conditions on the metric function of $(2+1)$-dimensional regular black hole in general relativity coupled with nonlinear electrodynamics sources. By the use of the two conditions, we obtain a general approach to construct $(2+1)$-dimensional regular black holes. In this manner, we construct four $(2+1)$-dimensional regular black holes as examples. We also study the thermodynamic properties of the regular black holes and verify the first law of black hole thermodynamics.Comment: 13 pages, 4 figures. in press in PL

Kinetics and Mechanisms of Phosphorus Adsorption in Soils from Diverse Ecological Zones in the Source Area of a Drinking-Water Reservoir.

On-site soils are increasingly used in the treatment and restoration of ecosystems to harmonize with the local landscape and minimize costs. Eight natural soils from diverse ecological zones in the source area of a drinking-water reservoir in central China are used as adsorbents for the uptake of phosphorus from aqueous solutions. The X-ray fluorescence (XRF) spectrometric and BET (Brunauer-Emmett-Teller) tests and the Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectral analyses are carried out to investigate the soils' chemical properties and their potential changes with adsorbed phosphorous from aqueous solutions. The intra-particle diffusion, pseudo-first-order, and pseudo-second-order kinetic models describe the adsorption kinetic processes. Our results indicate that the adsorption processes of phosphorus in soils occurred in three stages and that the rate-controlling steps are not solely dependent on intra-particle diffusion. A quantitative comparison of two kinetics models based on their linear and non-linear representations, and using the chi-square (χ2) test and the coefficient of determination (r2), indicates that the adsorptive properties of the soils are best described by the non-linear pseudo-second-order kinetic model. The adsorption characteristics of aqueous phosphorous are determined along with the essential kinetic parameters

Short Video Contents Production Based on Stickiness: Taking XinJing News “Our Video” as An Example

In the era of mobile connectivity, news production emphasizes the priority of mobile terminals. Video news becomes the mainstream of mobile news products. With the rapid development of short video market, media organizations have explored mobile video domain. Capital chases up short video contents entrepreneurship programs. Since 2016, short video has become a new venture of content entrepreneurship and has entered into an explosive development period. With the expansion of short video users and the increase of the length of use, there is a problem of vulgarization and homogenization in the communication of short video content. The problem of ecological construction of short video contents is further highlighted.The essay is taking XinJing News “Our Video” as an example to analyze short video production strategies based on stickiness. “Our Video” produces short videos based on the concept of professional journalism. It is becoming the leading video live broadcast and short video production platform in China. “Our Video” constructs product’s stickiness through double brand strategy and cross-border convergence communication. Through the video album serialization and continuous video reports, users’ deep use is shaped; Through live broadcast, users presence, participation and interaction, users’ experience is optimized and the users’ stickiness is strengthened. With the increasing competition of short video industry, the rapid growth of short video market and the higher expectation of users for contents, short video competition in the future is an ecological competition based on contents. Keywords: stickiness, short video, our video, information constructio

Thermodynamic and tachyonic instability for asymptotically flat black holes

It was confirmed that the negative modes of the Euclidean section for asymptotically flat black holes reveal the thermodynamic instability of these black holes in the grand canonical ensemble (GCE). These include Schwarzschild, Reissner-Nordstr\"{o}m, Kerr, and Kerr-Newman black holes. In this work, we develop the relation between thermodynamic instability in the GCE and tachyonic instability for asymptotically flat black holes, where the latter is the onset for obtaining black holes with scalar hair. This implies that the tachyonic instability of black holes when introducing scalar coupling to the Gauss-Bonnet term or Maxwell term reflects thermodynamic instability of these black holes in the GCE. We go on further to consider the Schwarzschild-AdS black hole.Comment: 19 pages, 5 figure