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Spectroscopy for a modified Schwarzschild black hole in noncommutative spacetimes is investigated. By utilizing an action invariance of black holes, the equally spaced entropy spectrum characteristic of Bekenstein’s original derivation is recovered. The derived spectrum is independent of the noncommutative parameter θ, and holds for all the existed noncommutative black holes independent of mass. On the other hand, the obtained area spectrum is not always equidistant due to the noncommutativity effects of the modified spacetimes. For large black holes, the equally spaced area spectrum spectrum can be obtained at the leading order in θ. But, for small black holes, the derived area spectrum is not equidistant, and it depends the noncommutative parameter. In addition, the one loop back reaction effect on the spectroscopy of the noncommutative Schwarzschild black hole is discussed. In this calculation, due to the back reaction effect, the equidistant area spectrum can not be obtained for all the noncommutative black holes with both large and small mass. Conversely, the back reaction effect has no influence on the entropy spectrum. The obtained entropy spectrum is equidistant and consistent with the original Bekenstein’s spectrum for all the existed noncommutative Schwarzschild black holes.

To explore and optimize the process of hydrogen production from plasma-assisted ammonia-cracking, a tubular ammonia-cracking on-site hydrogen production device with plasma-assisted ammonia combustion flue gas as the heat source was developed. Using the Temkin–Pyzhev kinetic model and the local thermal equilibrium (LTE) hypothesis, the effects of operating conditions, such as combustion flue gas temperature and ammonia flow rates, on ammonia-cracking efficiency were investigated. The numerical results are quantitatively consistent with the experiment. Ammonia cracking efficiency is notably influenced by the initial combustion gas temperature. When the gas velocity of the cracking system is less than or equal to 0.03 m/s, the cracking rate increases by 63% when the inlet temperature of the heat pipe changes from 700 K to 800 K. The cracking rate of ammonia decreased with the increase of ammonia flow rate, and this trend reached the maximum and began to weaken when the flow rate was 0.3 m/s. Longer catalyst bed length does not always mean higher cracking efficiency; the length of the cracking tube over 0.6 m shows little effect on cracking efficiency. Response surface methodology was used to conduct multi-factor analysis of the three main factors affecting the cracking rate of the cracker, namely, the temperature of the heating tube, the flow rate of flue gas in the heating process, and the inlet flow rate of the catalytic bed. It was found that the flow rate of the catalytic bed was the most significant factor affecting the cracking rate, which could be used as the main control method. The numerical results would provide technical guidance for industrial applications of on-site hydrogen production devices from ammonia decomposition. [ABSTRACT FROM AUTHOR]

Large‐scale arrays are widely used due to their advantages of high gain, high resolution, and strong beam control capability. The large number of antennas leads to a sharp increase in computational complexity, and thus, it is necessary to reduce the complexity of signal processing. A signal separation method is proposed based on subarray beam synthesis. This method can improve signal reception and separation performance through zero‐forcing calculation and realise system gain and phase error corrections in the front end of an antenna. Compared with back‐end processing, it has the advantage of low implementation difficulty. The feasibility and performance of the method are verified by simulations. [ABSTRACT FROM AUTHOR]

To investigate the quantum gravity effects on the black hole thermodynamics, we studied the phase transition in a quantum corrected Râ€"Nâ€"AdS black holes. First, based on the work of Kazakov and Solodukhin, the spherically symmetric quantum fluctuation is applied to Râ€"Nâ€"AdS black hole, and the metric is given. Next, we investigate the basic thermodynamic quantity and Smarr formula, and then propose that the quantum correction parameter a should also be treated as a variable to ensure the establishment of the new Smarr formula. Finally, the P â€" V diagram and phase transition for the quantum corrected Râ€"Nâ€"AdS black hole are studied. Compared with the existing research on Râ€"Nâ€"AdS black hole, some effects by quantum fluctuation are analyzed and presented. First, the quantum correction will weaken the charge effect of the black hole. Second, the P â€" V curve of the quantum corrected black hole is no longer analogous to that of Van Der Waals (VDW) gas exactly. Third, the black hole has two more phase states than Râ€"Nâ€"AdS black hole. One is a remnant phase state, the other is an unstable phase state. And both are derived from the quantum corrections of the black hole. [ABSTRACT FROM AUTHOR]

Metal oxide-based nano/microstructures assembled on heteroatom-doped carbon nanomaterials are promising materials to design the electrocatalysts with enhanced electrochemical performances. In this work, a systematic protocol was contrived to fabricate hybrid electrode material based on Cu2O microspheres (MSs) supported on sulfur-doped multiwalled carbon nanotubes (Cu2O MSs/S-MWCNTs). The adequate doping of sulfur and successful fabrication of Cu2O MSs/S-MWCNTs were confirmed by various microscopic and spectroscopic techniques, and then the tailor-made Cu2O MSs/S-MWCNTs composite was employed to establish a nonenzymatic sensing system for controlled monitoring of glucose. A high surface area of Cu2O MSs and sulfur doping inside the MWCNTs collectively enhanced the electrocatalytic activity of Cu2O MSs/S-MWCNTs as revealed through cyclic voltammetry (CV) analysis. The enhanced electrochemical efficacy of Cu2O MSs/S-MWCNTs may be credited to the creation of heterojunctions during the doping process, forming the highly defected structures with increased number of catalytic active sites. In addition, the Cu2O MSs/S-MWCNTs/GCE presented the good amperometric response for glucose sensing attaining optimal linear range, satisfactory sensitivity, excellent stability, and glucose specific selectivity. These unique chemical and electrochemical features strongly encourage the potential applicability of our designed Cu2O MSs/S-MWCNT electrocatalyst for targeted monitoring of glucose. [ABSTRACT FROM AUTHOR]

Taking into account the effect of the generalized uncertainty principle on the equation of the density of the states, we calculate the entropy of the quantum scalar field inside the brick-wall of the Garfinkle-Horowitz-Strominger dilaton black hole. The entropy proportional to the event horizon area is obtained without any cutoff. Compared to the entropy from the outside of the brick-wall, the two results are similar. This implies that the quantum theory of gravity can remove the divergence of the state density on the event horizon and avoid the cut-off in the original brick-wall model. [ABSTRACT FROM AUTHOR]