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The technique of magnetohydrodynamic (MHD) power generation has attracted a lot of interest as a potential means of improving the effectiveness and performance of hypersonic vehicle. Therefore, in current research the flow characteristics of the hypersonic vehicle nozzle with a magnetohydrodynamic generator (MHDG) at different incoming Mach numbers were analyzed to understand the effect of different parameters on the performance. The results showed that when the entrance incoming Mach number was below 1.1, the thermal choking effect occurred at the entrance of nozzle, so that reduction in the real Mach number is required to a certain value before the weakly ionized gas (WIG) entered the nozzle. As the value of entrance incoming Mach number approaches to 1.1, the thermal choking effect was strengthened at the nozzle entrance and the entrance real Mach number was descended, the power generation efficiency and the enthalpy extraction rate were declined. On the contrary, as value of entrance incoming Mach number exceeded 3, the entrance real Mach number became equal to the entrance incoming Mach number due to the absence of thermal choking, the power generation efficiency remained unaffected with the rise of the entrance incoming Mach number. Additionally, the power generation efficiency decreased as the magnetic field increased when the entrance incoming Mach number was set to 1.1, however, when the entrance incoming Mach number was set to 3, the effect of the magnetic field on the power generation efficiency vanished, and the power generation efficiency remained constant as the magnetic field increased.

Background: N6-methyladenosine (m6A) modification plays a crucial role in the regulation of diverse cellular processes influenced by environmental factors. Nevertheless, the involvement of m6A-modified long noncoding RNAs (lncRNAs) in the pathogenesis of lung injury induced by particulate matter (PM) remains largely unexplored. Methods: Here, we establish a mouse model of PM-induced lung injury. We utilized m6A-modified RNA immunoprecipitation sequencing (MeRIP-seq) to identify differentially expressed m6A peaks on long non-coding RNAs (lncRNAs). Concurrently, we performed lncRNA sequencing (lncRNA-seq) to determine the differentially expressed lncRNAs. The candidate m6A-modified lncRNAs in the lung tissues of mice were identified through the intersection of the data obtained from these two sequencing approaches. Results: A total of 664 hypermethylated m6A peaks on 644 lncRNAs and 367 hypomethylated m6A peaks on 358 lncRNAs are confirmed. We use bioinformatic tools to analyze the potential functions and pathways of these m6A-modified lncRNAs, revealing their involvement in regulating inflammation, immune response, and metabolism-related pathways. Three key m6A-modified lncRNAs (lncRNA NR_003508, lncRNA uc008scb.1, and lncRNA ENSMUST00000159072) are identified through a joint analysis of the MeRIP-seq and lncRNA-seq data, and their validation is carried out using MeRIP-PCR and qRT-PCR. Analysis of the coding-non-coding gene co-expression network reveals that m6A-modified lncRNAs NR_003508 and uc008scb.1 participate in regulating pathways associated with inflammation and immune response. Conclusions: This study first provides a comprehensive transcriptome-wide analysis of m6A methylation profiling in lncRNAs associated with PM-induced lung injury and identifies three pivotal candidate m6A-modified lncRNAs. These findings shed light on a novel regulatory mechanism underlying PM-induced lung injury. [ABSTRACT FROM AUTHOR]

Relativistic charged particle beam can be used as a destructive beam weapon in space for debris removal tasks. The trajectories of charged particles are affected by both electric and magnetic forces in the Earth's magnetic field. In this paper, we firstly analyzed the correlation parameters of the charged particle beam as a weapon when it is propagated in the geomagnetic field. Then, the models were constructed based on COMSOL Multiphysics, and the IGRF model was adopted in the simulation. The gyroradius and the related uncertainty were analyzed by simulation of the charged particle transport in the geomagnetic field at different altitudes. The charged beam spot radius divergency was also simulated. The geomagnetic field can inhibite the diffusion of the electron beam. [ABSTRACT FROM AUTHOR]

Magnetohydrodynamic (MHD) is one of the most promising novel propulsion technologies with the advantages of no pollution, high specific impulse, and high acceleration efficiency. As the carrier of this technology, the MHD accelerator has enormous potential for applications in hypersonic wind tunnels, supersonic ramjet engines, and deep space propulsion. In this study, a three-dimensional numerical simulation of an ideal Faraday magnetohydrodynamic (MHD) accelerator is conducted to assess the effect on performance with respect to applied potential and magnetic field intensity. The study is performed by employing a low magnetic Reynolds number MHD model coupled with a 7-component chemical reaction model to simplify the impact of real gas effects. The chemical reaction exhibits an increasing trend with rising applied potential and a decreasing trend with diminishing magnetic field strength. This variation influences the gas conductivity, subsequently affecting the velocity and thrust of the system. Specifically, at a magnetic field intensity of 2.0 T and an applied potential of 600 V, the accelerator exhibits maximum velocity and thrust growth rates of 18.6% and 59.8%, respectively. [ABSTRACT FROM AUTHOR]

The synchrosqueezing transform (SST) has attracted much attention as a post-processing technique since it was proposed. In recent years, improvements to SST have been made. However, the existing methods are mainly based on the time-domain signal model, and the weak frequency modulation assumption for the components composing the signal is always taken into account. Thus, the signals characterized by a rapidly changing instantaneous frequency (IF) may fail to be adequately tackled. To address this problem, the paper presents a novel seismic time–frequency analysis method via synchrosqueezing transform where a frequency-domain Gaussian modulated linear chirp model is utilized to deduce the SST. The group delay (GD) rather than the IF estimator is implemented to compute an estimation of the ridge. Furthermore, a new synchrosqueezing operator is constructed to rearrange the energy around the ridge. A synthetic example verifies the efficiency and robustness of the proposed SST method, which generates better results than some classic time–frequency analysis (TFA) approaches, e.g., short-time Fourier transform (STFT) and STFT-based SST (FSST). A field dataset further demonstrates this method's potential in the delineation of subsurface geological structures. [ABSTRACT FROM AUTHOR]