The dynamic features of the low-intermediate-high-(L-I-H) confinement transitions on HL-2A tokamak are presented. Here we report the discovery of two types of limit cycles (dubbed type-Y and type-J), ...which show opposite temporal ordering between the radial electric field and turbulence intensity. In type-Y, which appears first after an L-I transition, the turbulence grows first, followed by the localized electric field. In contrast, the electric field leads type-J. The turbulence-induced zonal flow and pressure-gradient-induced drift play essential roles in the two types of limit cycles, respectively. The condition of transition between types-Y and -J is studied in terms of the normalized radial electric field. An I-H transition is demonstrated to occur only from type-J.
Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the primary pathogens that causes severe economic losses to sericulture. Comparative transcriptomics analysis has been widely applied to explore the ...antiviral mechanism in resistant strains. Here, to identify genes involved in BmNPV infection, we identified differentially expressed genes (DEGs) and performed weighted gene co‐expression network analysis (WGCNA) between two Bombyx mori strains: strain 871 (susceptible to BmNPV infection) and the near‐isogenic strain 871C (resistant to BmNPV). Our results showed that 400 genes were associated with resistance in strain 871C, and 76 genes were related to susceptibility in strain 871. In addition, the correlation analysis of DEGs and WGCNA showed that 40 genes related to resistance were highly expressed in the resistant strain. Among them, gene BGIBMGA004291 was the most noticeable. We further identified the effect of gene BGIBMGA004291, which encoded a multiprotein bridge factor 2 (MBF2) family member (MBF2‐10), on viral infection in cells. Our data suggested that MBF2‐10 inhibited viral infection. Taken together, this study showed specific module trait correlations related to viral infection in strains 871 and 871C, and we identified a resistance‐related gene. These findings suggested promising candidate genes with antiviral activity, aiding in the analysis of the antiviral molecular mechanisms in resistant strains.
Abstract
In this study, we introduced a quantitative parameter, the magnetic field strength difference, to denote the intensity of the magnetic pileup effect at Mars. Using a three-dimensional ...multispecies MHD model, the effects of the interplanetary magnetic field (IMF) and the solar wind dynamic pressure (
P
d
) constituted with different densities and velocities on the magnetic pileup were examined. Our results show that: (1) the magnetic pileup at Mars mainly occurs at the dayside region and its magnitude is generally decreasing with increasing solar zenith angle. The magnetic pileup is generally weak in the intense crustal field region, while it is strong in the weak crustal field region. (2) The perpendicular IMF components,
B
Y
and
B
Z
, dominate the magnetic pileup, while the radial IMF component,
B
X
, has little effect. In the intense crustal field region, when the IMF and crustal field are primarily in the same direction, the magnetic field is piled up and the pileup magnitude is generally strong. While the directions of the crustal field and IMF are opposite, the occurrence of magnetic reconnection can weaken the local magnetic pileup. (3) Under the same
P
d
, a higher solar wind velocity results in a higher intensity and a larger region of the magnetic pileup. When
P
d
increases, the magnitude of the magnetic pileup is enhanced, but the pileup region shrinks. In addition, for an increasing
P
d
, at the center of the induced magnetotail, the asymmetric current sheet can lead to similar asymmetries of the pileup.
A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} ...antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton pover ¯, proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (pover ¯/p), (pover ¯/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (pover ¯/p), (pover ¯/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense ...examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.
Abstract
The effects of a coherent mode (CM) at a frequency of
f
= 13–16 kHz on the redistribution of divertor particle flux have been studied in HL-2A H-mode plasmas using multiple diagnostics. The ...experimental results demonstrate that a CM localized at the middle of the pedestal results in outward particle transport, limiting the growth of the pedestal density gradient in the recovery phase of the pedestal, leading to a substantial increase in the localized particle flux striking the outer divertor target, which clearly deviates from the primary peak at the strike point. These observations indicate that the CM might play a crucial role in redistributing the divertor particle flux, which is important for understanding and controlling the divertor heat flux in future fusion-relevant devices.
Abstract
In this paper, using a three-dimensional multispecies MHD model, we study the effect of the interplanetary magnetic field (IMF) intensity and orientation on the subsolar standoff distance of ...the Martian magnetic pileup boundary (
r
0
) and the pressure balance across it. The results show that: (1) with the increasing magnitude of the
Y-
or
Z-
component of the IMF,
B
Y
or
B
Z
,
r
0
increases, while the radial IMF component,
B
X
, has little effect. With the increasing magnitude of
B
Y
or
B
Z
, the compression degree of the magnetic field (
f
) increases, while the solar wind pressure coefficient (
k
) remains unchanged, resulting in the enhancement of
r
0
. (2) Under the same IMF intensity,
B
t
, the impact of the IMF cone angle on
r
0
and
f
is controlled by the ratio of the IMF
Y-
and
Z-
components to
B
t
,
B
Y
2
+
B
Z
2
/
B
t
. When the ratio is enhanced, both
r
0
and
f
increase, while
k
generally remains unchanged. Compared with the IMF cone angle, the influence of the IMF clock angle is relatively less. We suggest that the stronger magnetic pileup process controlled by the perpendicular IMFs (
B
Y
or
B
Z
) causes the larger
r
0
, while the weaker magnetic pileup under the radial IMF leads to the smaller
r
0
. The difference in the IMF effect on the size of the Martian magnetic pileup boundary and the terrestrial magnetopause reveals different solar wind interactions with a magnetized and unmagnetized planet. Last, the location of the intense crustal field can also affect
r
0
and the pressure balance condition, and the specific impact needs to be further studied.
A novel approach for positron injection and acceleration in the laser driven plasma wakefield is proposed. One ring-shaped beam and one coaxially propagating Gaussian beam drive wakefields in a ...preformed plasma volume filled with both electrons and positrons. The laser’s ponderomotive force as well as the charge separation force in the front bucket of the first bubble are utilized to provide the transverse momenta of injected positrons and those positrons can be trapped by the focusing field and then accelerated by the wakefield. Theoretical analysis of the process is presented and verified by particle-in-cell simulations. The simulations show that relatively high-charge, quasimonoenergetic positron beams can be obtained.
We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of ...1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3 GV the p/He flux ratio is time independent. We observed that below ∼3 GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.
Abstract
We report the observations of periodic nulling in PSR B2111+46 at 1250 MHz with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The nulling fractions (NF) as well as ...nulling period of this pulsar were calculated. The NF and nulling period are 17% ± 1% and 62.49 ± 0.99
P
1
, respectively, and the periodic nulling shows variations in periodicity with time. The durations of each consecutive burst and nulling were investigated, which show that the power-law distribution and the indices are −1.11 ± 0.04 and −2.08 ± 0.23. In the observed frequency band, the width of the profile is narrowed with the increase in frequency, and the degree of polarization has no obvious trend with the increase in frequency. We discovered a weak emission component in front of the leading component of this triple-type profile pulsar that was not observed in other bands and by other telescopes. With the fitting of rotation vector model, we obtained that the angles of the magnetic inclination
α
and the line of sight
ζ
are ∼13.°0 and ∼11.°6, respectively. The high-sensitivity observation of FAST improves our understanding of the emission of this pulsar.
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