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Strong evidence of the existence of the Stochastic Gravitational-Wave Background (SGWB) has been reported by the NANOGrav, PPTA, EPTA and CPTA collaborations. The Bayesian posteriors of the Gravitational-Wave Background (GWB) amplitude and spectrum are compatible with current astrophysical predictions for the GWB from the population of supermassive black hole binaries (SMBHBs). In this paper, we discuss the corrections arising from the extra scalar or vector radiation to the characteristic dimensionless strain in PTA experiments and explore the possibility to detect charges surrounding massive black holes, which could give rise to SGWB with vector or scalar polarizations. The parametrized frequency-dependent characteristic dimensionless strain is used to take a Bayesian analysis and the Bayes factor is also computed for charged and neutral SMBHBs. The Bayesian posterior of GWB tensor amplitude is $\log_{10} A_T=-14.85^{+0.26}_{-0.38}$ and spectral exponent $\alpha=-0.60^{+0.32}_{-0.36}$. The Bayesian posterior for vector or scalar amplitude $A_{V, S}$ is nearly flat and there is nearly no constraint from the current observation data. The Bayesian factor is $0.71$ far less than 100, so the current observation can not support the existence of the charged SMBHB., Comment: 15 pages, 3 figures; Comments are welcome

Hubble tension is one of the most important problems in cosmology. The local measurements on the Hubble constant with Type Ia supernovae (SNe Ia) suffer from the problem of zero-point calibration of the luminosity distance. The observations of gravitational waves (GWs) with space-based GW detectors can measure the luminosity distance of the GW source with high precision. By assuming that massive binary black hole mergers and SNe Ia occur in the same host galaxy, we study the possibility of re-calibrating the luminosity distances of SNe Ia by GWs. Then we use re-calibrated SNe Ia to determine the local Hubble constant. We find that we need at least 7 SNe Ia with their luminosity distances re-calibrated by GWs to reach a 2\% precision of the local Hubble constant. The value of the local Hubble constant is free from the problems of zero-point calibration and model dependence, so the result can shed light on the Hubble tension., Comment: 22 pages, 5 figures, 2 tables; Comments are welcome

In this paper, the fault discrimination method of GIS equipment is studied, and a method for detecting the gas composition of the insulation fault characteristic in the air switch cabinet is proposed. First, analyze the decomposition mechanism of partial discharge air in the air under the condition of insulation fault, determine the characteristic gas of insulation fault as the detection object, and analyze the influencing factors that affect the characteristics of the characteristic gas. Then establish a simulation model for the air switch cabinet, analyze the flow characteristics of the indoor gas, and establish the installation position of the characteristic gas detection sensor on this basis.

Distributed generation access to distribution network will change its power flow and node voltage distribution, which may affect the safe and stable operation of distribution network. In this paper, the minimum active power loss is taken as the objective to model the distribution network with distributed generations, and the extremum optimization algorithm is introduced to improve it. Finally, an example is given to verify the superiority of the improved algorithm over other typical optimization algorithms.

In practice, the output impedance and lead impedance of the parallel inverter are often inconsistent, and the inconsistency of the equivalent impedance also causes uneven power between the inverters. In this thesis, the parallel inverter system circulating current is analyzed, and the output impedance inconsistency problem is improved by adaptive virtual impedance. The virtual impedance is different from the actual output impedance, which can optimize the power sharing problem without introducing additional power loss.

The increased use of triboelectric nanogenerators (TENGs) has shown that enhancement of the output performance is a primary requirement for their development. Here, a synergistic enhancement via dielectric and dispersity modulation in nanoscale is reported for a novel barium titanate-doped coaxial nanofiber-based triboelectric nanogenerator (BTCN-TENG). Polydimethylsiloxane (PDMS) and barium titanate nanoparticles (BT NPs) are combined as the core of the coaxial nanofiber instead of conventional composite film by in situ curing during electrospinning process, and BT NPs incorporated in the PDMS core layer are shown to effectively increase the dielectric constant of the composite nanofiber mat as well as the output performance of the BTCN-TENG. Furthermore, an improved dispersity of BT NPs in the PDMS core layer compared to that achieved in the poly(vinylidene fluoride) (PVDF) shell layer was found to contribute significantly to the output performance of the BTCN-TNEG. The optimized BTCN-TENG exhibits a high output voltage of 1020 V, a current of 29 μA, and a maximum power density of 2.2 W/m2 under a 30 MΩ load resistance. In power supply application, the BTCN-TENG could successfully drive various electronic devices via mechanical energy conversion.

Ferroresonance overvoltage is one of the most important factors to impact electric equipment inner insulation. In system with non-effectively earthed neutral, the equipment damage caused by ferroresonance overvoltage possesses great proportion. This paper derives the criterion of power frequency ferroresonance in system with non-effectively earthed neutral in detailed, in order to conveniently judge whether there is power frequency ferroresonance when system transferring working mode. This criterion derives the relation between equivalent circuit resistance and critical resistance using analytical method and can be used for determining the zero sequence resistance value in cascade with PT secondary side for eliminating ferroresonance. The method is verified by an example under two conditions. Finally, the effect of neutral connecting arc suppression coil on ferroresonance is analyzed.

Nano-structured Platinum-Yttria Stabilized Zirconia (YSZ) composites for oxygen potentiometric sensors were directly prepared with carbon black and the precursors such as chloroplatinic acid, zirconyl nitrate and yttrium nitrate. The as-prepared Pt-YSZ composite consisted of cubic crystalline YSZ and Pt particles, and the particle sizes of Pt catalyst and YSZ electrolyte were about 25-35 and 5-10 nm, respectively. The Pt-YSZ composite electrodes exhibited excellent electrochemical performances when evaluated by EIS measurements. The introduction of the nano-structured Pt-YSZ composite into the oxygen potentiometric sensor can reduce sensor's operating temperature to be about 380 degrees C, and also can reduce sensor's response time to be about 5 s at 400 degrees C. The oxygen potentiometric sensors incorporating nano-structured Pt-YSZ composites exhibited longer lifetime than those employing pure Pt as the sensing electrodes. (C) 2011 Elsevier B.V. All rights reserved.

Thin film of lanthanum nickelate (LaNiO3) has been prepared by the sol-gel process based on the amorphous citrate precursors. The sheet resistance of LaNiO3 thin film greatly decreases and trends towards a stable value with increasing the repeated dipping-calcining cycles. The sheet resistance of about 1.2 mu m thick LaNiO3 thin film produced by the dipping-calcining 10 cycles is about 22.4 Omega at room temperature and less sensitive to temperature in the P-O2 range from 10(3.3) to 10(5) Pa or in the lean-burn region (lambda = 1.15). The sensitivity and response characteristics of the LaNiO3 thin film sensor have been investigated in the exhaust gas of air-propane combustion. It has been shown that thin film sensor has high sensitivity, fairly good response and reproducibility from h = 1.15 to 0.85 and vice versa, and no temperature compensation is needed for stoichiometric air/fuel control over a 300-800 degrees C range. The thin film sensor is a promising A/F sensitive sensor that needs no temperature compensation. (C) 2000 Elsevier Science S.A. All rights reserved.