876 research outputs found
GRB 211211A-like Events and How Gravitational Waves May Tell Their Origin
GRB 211211A is a rare burst with a genuinely long duration, yet its prominent
kilonova association provides compelling evidence that this peculiar burst was
the result of a compact binary merger. However, the exact nature of the merging
objects, whether they were neutron star pairs, neutron star-black hole systems,
or neutron star-white dwarf systems, remains unsettled. This Letter delves into
the rarity of this event and the possibility of using current and
next-generation gravitational wave detectors to distinguish between the various
types of binary systems. Our research reveals an event rate density of for GRB
211211A-like GRBs, which is significantly smaller than that of typical long and
short GRB populations. We further calculated that if the origin of GRB 211211A
is a result of a neutron star-black hole merger, it would be detectable with a
significant signal-to-noise ratio, given the LIGO-Virgo-KAGRA designed
sensitivity. On the other hand, a neutron star-white dwarf binary would also
produce a considerable signal-to-noise ratio during the inspiral phase at
decihertz and is detectable by next-generation space-borne detectors DECIGO and
BBO. However, to detect this type of system with millihertz space-borne
detectors like LISA, Taiji, and TianQin, the event must be very close,
approximately 3 Mpc in distance or smaller.Comment: 8 pages, 3 figures, 1 tabl
dmPFC-vlPAG projection neurons contribute to pain threshold maintenance and antianxiety behaviors
The dorsal medial prefrontal cortex (dmPFC) has been recognized as a key cortical area for nociceptive modulation. However, the underlying neural pathway and the function of specific cell types remain largely unclear. Here, we show that lesions in the dmPFC induced an algesic and anxious state. Using multiple tracing methods including a rabies-based transsynaptic tracing method, we outlined an excitatory descending neural pathway from the dmPFC to the ventrolateral periaqueductal gray (vlPAG). Specific activation of the dmPFC/vlPAG neural pathway by optogenetic manipulation produced analgesic and antianxiety effects in a mouse model of chronic pain. Inhibitory neurons in the dmPFC were specifically activated using a chemogenetic approach, which logically produced an algesic and anxious state under both normal and chronic pain conditions. Antagonists of the GABAA receptor (GABAAR) or mGluR1 were applied to the dmPFC, which produced analgesic and antianxiety effects. In summary, the results of our study suggest that the dmPFC/vlPAG neural pathway might participate in the maintenance of pain thresholds and antianxiety behaviors under normal conditions, while silencing or suppressing the dmPFC/vlPAG pathway might be involved in the initial stages and maintenance of chronic pain and the emergence of anxiety-like behaviors
Experimental Free-Space Distribution of Entangled Photon Pairs over a Noisy Ground Atmosphere of 13km
We report free-space distribution of entangled photon pairs over a noisy
ground atmosphere of 13km. It is shown that the desired entanglement can still
survive after the two entangled photons have passed through the noisy ground
atmosphere. This is confirmed by observing a space-like separated violation of
Bell inequality of . On this basis, we exploit the distributed
entangled photon source to demonstrate the BB84 quantum cryptography scheme.
The distribution distance of entangled photon pairs achieved in the experiment
is for the first time well beyond the effective thickness of the aerosphere,
hence presenting a significant step towards satellite-based global quantum
communication.Comment: 4 pages, 3 figure
Strong-Coupling Superconductivity with 10.8 K Induced by P Doping in the Topological Semimetal MoSi
By performing P doping on the Si sites in the topological semimetal
MoSi, we discover strong-coupling superconductivity in
MoSiP (0.5 2.0). MoSi crystallizes in
the WSi-type structure with space group of (No. 140), and is
not a superconductor itself. Upon P doping, the lattice parameter decreases
while increases monotonously. Bulk superconductivity is revealed in
MoSiP (0.5 2.0) from resistivity,
magnetization, and heat capacity measurements. in
MoSiP reaches as high as 10.8 K, setting a new record among
the WSi-type superconductors. The upper and lower critical fields for
MoSiP are 14.56 T and 105 mT, respectively. Moreover,
MoSiP is found to be a fully gapped superconductor with
strong electron-phonon coupling. First-principles calculations suggest that the
enhancement of electron-phonon coupling is possibly due to the shift of the
Fermi level, which is induced by electron doping. The calculations also reveal
the nontrivial band topology in MoSi. The and upper critical
field in MoSiP are fairly high among pseudobinary compounds.
Both of them are higher than those in NbTi, making future applications
promising. Our results suggest that the WSi-type compounds are ideal
platforms to search for new superconductors. By examinations of their band
topologies, more candidates for topological superconductors can be expected in
this structural family.Comment: 15 pages, 5 figures. Supplementary Information availabe at the
corresponding DO
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