The sizes of BLRs and BH masses of double-peaked broad low-ionization emission line objects

In this paper, the sizes of the BLRs and BH masses of DouBle-Peaked broad low-ionization emission line emitters (dbp emitters) are compared using different methods: virial BH masses vs BH masses from stellar velocity dispersions, the size of BLRs from the continuum luminosity vs the size of BLRs from the accretion disk model. First, the virial BH masses of dbp emitters estimated by the continumm luminosity and line width of broad H$\beta$ are about six times (a much larger value, if including another dbp emitters, of which the stellar velocity dispersions are traced by the line widths of narrow emission lines) larger than the BH masses estimated from the relation $M_{BH} - \sigma$ which is a more accurate relation to estimate BH masses. Second, the sizes of the BLRs of dbp emitters estimated by the empirical relation of $R_{BLR} - L_{5100\AA}$ are about three times (a much larger value, if including another dbp emitters, of which the stellar velocity dispersions are traced by the line widths of narrow emission lines) larger than the mean flux-weighted sizes of BLRs of dbp emitters estimated by the accretion disk model. The higher electron density of BLRs of dbp emitters would be the main reason which leads to smaller size of BLRs than the predicted value from the continuum luminosity.Comment: 7 pages, two figures and one table. Accepted by MNRA

Constraining the Mass of the Photon with Gamma-Ray Bursts

One of the cornerstones of modern physics is Einstein's special relativity, with its constant speed of light and zero photon mass assumptions. Constraint on the rest mass m_{\gamma} of photons is a fundamental way to test Einstein's theory, as well as other essential electromagnetic and particle theories. Since non-zero photon mass can give rise to frequency-(or energy-) dependent dispersions, measuring the time delay of photons with different frequencies emitted from explosive astrophysical events is an important and model-independent method to put such a constraint. The cosmological gamma-ray bursts (GRBs), with short time scales, high redshifts as well as broadband prompt and afterglow emissions, provide an ideal testbed for m_{\gamma} constraints. In this paper we calculate the upper limits of the photon mass with GRB early time radio afterglow observations as well as multi-band radio peaks, thus improve the results of Schaefer (1999) by nearly half an order of magnitude.Comment: 25 pages, 2 tables, Accepted by Journal of High Energy Astrophysic

The Correlation Between Spectral Index And Accretion Rate For AGN

In this paper, we present a correlation between the spectral index distribution (SED) and the dimensionless accretion rate defined as $\dot{m}={L_{bol}/L_{Edd}}$ for AGN. This quantity is used as a substitute of the physical accretion rate. We select 193 AGN with both broad H$\alpha$ and broad H$\beta$, and with absorption lines near MgI$\lambda5175\AA$ from SDSS DR4. We determine the spectral index and dimensionless accretion rate after correcting for both host galaxy contribution and internal reddening effects. A correlation is found between the optical spectral index and the dimensionless accretion rate for AGN, including low luminosity AGN ($L_{H\alpha}<10^{41}{\rm erg\cdot s^{-1}}$ sometimes called "dwarf AGN" (Ho et al. 1997)). The existence of this correlation provides an independent method to estimate the central BH masses for all types of AGN. We also find that there is a different correlation between the spectral index and the BH masses for normal AGN and low luminosity AGN, which is perhaps due to the different accretion modes in these two types of nuclei. This in turn may lead to the different correlations between BH masses and optical continuum luminosity reported previously (Zhang et al. 2007a), which invalidates the application of the empirical relationship found by Kaspi et al. (2000, 2005) to low luminosity AGN in order to determine their BLR sizes.Comment: 10 pages, 7 figures, accepted for publication in MNRA

The size of BLRs of low luminous Active Galactic Nuclei

We study the size of BLRs of low luminosity Active Galactic Nuclei, also called 'dwarf AGN', defined as having ($L_{H\alpha}\le10^{41}{\rm erg\cdot s^{-1}}$)). We more than double the sample size analyzed previously (Wang & Zhang 2003, hereafter Paper I). In this study we first confirm our previous result that the sizes of BLRs of low luminosity AGN are larger than the ones expected from the empirical relation $R_{BLRs} - L_{H\alpha}$ valid for 'normal' AGN: Seyfert 1s and quasars, except for the objects with accretion rate $\dot{m_{H\alpha}}>10^{-5.5}$. Second, we find a positive correlation between the line width of the narrow emission line (as tracer of velocity dipersion and thus bulge and black hole mass) and the size of BLRs for both normal and low luminosity AGN. In this paper we find a non-linear dependence of the BLRs sizes of low luminosity AGN on BH masses. We also show that their sizes of BLRs are more strongly dominated by the 'specific accretion rate' $\dot{m_{H\alpha}}$ defined as $\dot{m_{H\alpha}} = L_{H\alpha}/L_{Edd}$, than by the masses of their cetral black holes. As an expected result, the distance of emission regions of low-ionization broad H$\alpha$ of NGC 4395 should be consistent with the value from the empirical relation of $R_{BLRs} - L_{H\alpha}$, according to the high accretion rate.Comment: Accepted by MNRA

Mechanism and influence factor of hydrocarbon gas diffusion in porous media with shale oil

Due to the compactness of shale reservoir matrix and the high conductivity of fractures, the hydrocarbon gas injection huff and puff method or displacement is the most realistic technology to improve shale oil recovery. The diffusion mechanism plays an important role in shale oil development; therefore, it is crucial to figure out the factors influencing diffusion, which could enhance shale oil recovery. In this paper, a physical simulation experiment is designed to evaluate the diffusion ability of  hydrocarbon gas. Diffusion experiments are conducted to simulate diffusion in the bulk fluid and in the porous media, to learn about how the pressure, permeability and fracture affect the diffusion behavior. The diffusion coefficients between the bulk diffusion and core sample diffusion are compared. The experimental results show that the diffusion coefficient and mass transfer capacity are positively correlated with permeability and pressure: increasing these parameters can promote the diffusion process. The diffusion coefficient of  hydrocarbon gas in a saturated oil core is significantly less than that in crude oil, which indicates that the porous media seriously affects the process of gas diffusion in crude oil. Fractures have little impact on the diffusion behavior. Combined with numerical simulation, the influencing factor of diffusion on the development effect of hydrocarbon gas injection is clarified. The recovery enhances and then decreases with the increasing diffusion  coefficient.Cited as: Wanyan, Z., Liu, Y., Li, Z., Zhang, C., Liu, Y., Xue, T. Mechanism and influence factor of hydrocarbon gas diffusion in porous media with shale oil. Advances in Geo-Energy Research, 2023, 7(1): 39-48. https://doi.org/10.46690/ager.2023.01.0

Effectiveness and safety of Wuling capsule for post stroke depression: A systematic review

SummaryObjectiveTo review the effectiveness and safety of Wuling capsule for post stroke depression (PSD) systematically.MethodsWe searched electronic databases for randomized controlled trials (RCTs) that compared either Wuling capsule with placebo, no treatment or Wuling capsule plus conventional treatment with conventional treatment alone in adults with post stroke depression. Relevant resources were also retrieved. Two reviewers screened the citations, assessed the risk of bias and extracted data independently.ResultsA total of 16 studies involving 1378 patients were identified for this review. There were 3 trials comparing Wuling capsule with no treatment control and 13 trials comparing Wuling capsule plus conventional treatment (Deanxit, Fluoxetine, Sertraline, Paroxetine or Citalopram) with conventional treatment alone. Meta-analyses indicated Wuling capsule used alone or integrated with conventional treatment was effective for PSD in terms of HAMD (Hamilton depression scale) scores, response rate and with less adverse effects, of which, HAMD scores decreased significantly in favor of Wuling capsule from onset time to 1 week (SMD=1.27, 95%CI: 0.71–1.83, P<0.00001), 2 weeks (SMD=1.45, 95%CI: 0.57–2.33, P=0.001), 4 weeks (SMD=2.84, 95%CI: 2.15–3.52, P<0.00001), 6 weeks (SMD=2.70, 95%CI: 2.15–3.24, P<0.00001), and 8 weeks (SMD=4.53, 95%CI: 3.55–5.50, P<0.00001) and overall effect (SMD=2.40, 95%CI: 1.75–3.05, P<0.00001) (SMD=standardized mean difference).ConclusionWuling capsule appeared to present certain antidepressant effect compared to no treatment control. With a combination of several Western medicines, Wuling capsule could be helpful in strengthening efficacy and reducing the incidence of adverse events as an alternative choice in the treatment of PSD. However, due to the limited number of included trials and relatively moderate methodological quality in the majority of studies, further large scale and rigorously designed trials are warranted to confirm the effectiveness and safety of Wuling capsule for post stroke depression

Multi-axis fatigue loading system of wind turbine blade and vibration coupling characteristics

This paper presents a new method which focuses on the multi-axis fatigue loading mode for wind turbine blade and aims to shorten the fatigue loading cycle. The whole test scheme is design for the measurement of fatigue loading system. The two leading sources of fatigue loading system are asymmetric arrangement in the space. In addition, its vibration mathematical model is derived according to the Lagrange equation. The numerical simulation model is developed by means of Matlab Simulink. The vibration coupling characteristics including motor revolution speed, phase and amplitude of wind turbine blade is obtained. Moreover, the trajectory of wind turbine blade is obtained. Finally, a multi-axis fatigue loading platform for small wind turbine blade is built for the proposed study. The on-site test showed that if the revolution speeds of the two loading sources is the same as the natural frequency of wind turbine blade, the revolution speed, the phase angle of motor and the blade trajectory were relative changed smoothly. Thus, the amplitude of blade is state and the largest. Otherwise when the revolution speed of motor is different with the natural frequency of blade, the revolution speeds and phase angle of the two loading sources fluctuated largely. The above conclusion provided the theoretical basis for the subsequent decoupling control algorithm of multi-axis fatigue loading test