Lyapunov Exponents and Phase Transitions of Born-Infeld AdS Black Holes

In this paper, we characterize the phase transitons of Born-Infeld AdS black holes in terms of Lyapunov exponents. We calculate the Lyapunov exponents for both null and timelike geodesics. It is found that black hole phase transitions can be described by multiple-valued Lyapunov exponents. And its phase diagram can be characterized by Lyapunov exponents and Hawking temperature. Besides, the change of Lyapunov exponents can be considered as order parameter, and exists a critical exponent $1/2$ near critical point.Comment: 22 pages, 21 figure

FAF: A novel multimodal emotion recognition approach integrating face, body and text

Multimodal emotion analysis performed better in emotion recognition depending on more comprehensive emotional clues and multimodal emotion dataset. In this paper, we developed a large multimodal emotion dataset, named "HED" dataset, to facilitate the emotion recognition task, and accordingly propose a multimodal emotion recognition method. To promote recognition accuracy, "Feature After Feature" framework was used to explore crucial emotional information from the aligned face, body and text samples. We employ various benchmarks to evaluate the "HED" dataset and compare the performance with our method. The results show that the five classification accuracy of the proposed multimodal fusion method is about 83.75%, and the performance is improved by 1.83%, 9.38%, and 21.62% respectively compared with that of individual modalities. The complementarity between each channel is effectively used to improve the performance of emotion recognition. We had also established a multimodal online emotion prediction platform, aiming to provide free emotion prediction to more users

Microstructure of Charged AdS Black Hole with Minimal Length Effects

In this work, the microstructure of charged AdS black holes under minimal length effects is investigated. We study the thermodynamics of black holes in the extended phase space, where the cosmological constant is regarded as the thermodynamic pressure. The modified Hawking temperature and phase transition are obtained based on the generalized uncertainty principle (GUP). Then, using thermodynamic geometry, we show that the microstructure of black holes can be determined by the ratio of GUP parameter to charge. For a small ratio, the black hole exhibits the typical RN-AdS microstructure with van der Waals phase transition and repulsive/attractive interactions. As the ratio increases, the reentrant phase transition takes place, and both the repulsion-attraction coexisted black hole and the attraction dominated black hole can be found in this case. For a large ratio, the black hole behaves like a Schwarzchild-AdS black hole in which neither phase transition nor repulsive interaction exists. These results suggest that the GUP effect will reduce the repulsive interaction presented by the charged AdS black hole, which can also be qualitatively understood from the perspective of black hole molecules.Comment: 29 pages, 10 figure

Introduction and demonstration of a novel Pb(II)-imprinted polymeric membrane with high selectivity and reusability for treatment of lead contaminated water

10.1016/j.jcis.2014.09.073Journal of Colloid and Interface Science439162-16

Effects of Born–Infeld electrodynamics on black hole shadows

In this work, we study the shadow of Born–Infeld (BI) black holes with magnetic monopoles and Schwarzschild black holes immersed in the BI uniform magnetic field. Illuminated by a celestial sphere, black hole images are obtained by using the backward ray-tracing method. For magnetically charged BI black holes, we find that the shadow radius increases with the increase of nonlinear electromagnetics effects. For Schwarzschild black holes immersed in the BI uniform magnetic field, photons tend to move towards the axis of symmetric, resulting in stretched shadows along the equatorial plane

Removal of microplastics in water: Technology progress and green strategies

Microplastics (MPs) are globally distributed in aquatic environments, and become a growing threat to the ecosystem. It is urgently needed to develop effective technologies to remove MPs from water. In this review, we summarized progress in major technologies for the removal of MPs. Currently, multiple technologies for MPs removal have been developed including physical, chemical, and biological approaches. Filtration technology has a various removal efficiency, but a relatively high cost due to membrane fouling and replacing new filter membranes. The approach of adsorption and magnetic separation is a simple removal method; however, additive sorbents may cause secondary pollution. There is a similar problem of chemical residua in coagulation and oxidation treatment. In contrast, biodegradation and bioreactors are often of a low degradation efficiency. Then, existing removal technologies were comparatively analyzed in several aspects, especially practical efficiency and environmental impacts. Finally, green strategies for plastic abatement were proposed, including zero pollutant removal technology, integrated environmentally friendly approaches, recycling use of conventional plastic, and developing biodegradable plastic in the future

High-Performance Self-Powered Transparent Metal–Semiconductor-Metal Ultraviolet Photodetector Based on Sub-10 nm Thick Dual-Asymmetric Interdigitated Electrodes

Transparent self-powered ultraviolet (UV) photodetectors (PDs) are demonstrated experimentally with dual-asymmetric interdigitated electrodes composed of Au and Ag with different sizes on top of a ZnO active layer. The electrodes are sub-10 nm thick and highly transparent in both UV and visible regimes, making the whole device look transparent and output light current over 1/3 higher than that of the counterpart with thick opaque electrodes at 0 V. The PD with only electrode material asymmetry can work at 0 V because of the Schottky junction formed at the Au/ZnO interface and the Ohmic contact at the Ag/ZnO interface. The junction asymmetry can be further enhanced by the electrode size difference. The PD with a Au and Ag finger width ratio of 1:4 achieves a photocurrent over 11 times that of the device with identical Au and Ag sizes. A high responsivity of 56.3 μA/W and a high detectivity of 1.54 × 108 Jones are achieved. The rise and fall times are as low as 3.1 and 2.8 ms, respectively. By patterning the pads, our PD becomes more uniform and transparent with an average visible transmissivity improved to 77.6% (the highest among the UV PD chips reported), while the optoelectronic conversion performance remains unchanged. The overall properties are comparable and even superior to those of the previously reported counterparts. This work provides insights into the design and mechanism of transparent self-powered UV PDs, facilitating advancements in this field