The ultra-fast dynamics of superconducting vortices harbors rich physics generic to nonequilibrium collective systems. The phenomenon of flux-flow instability (FFI), however, prevents its exploration ...and sets practical limits for the use of vortices in various applications. To suppress the FFI, a superconductor should exhibit a rarely achieved combination of properties: weak volume pinning, close-to-depairing critical current, and fast heat removal from heated electrons. Here, we demonstrate experimentally ultra-fast vortex motion at velocities of 10-15 km s
in a directly written Nb-C superconductor with a close-to-perfect edge barrier. The spatial evolution of the FFI is described using the edge-controlled FFI model, implying a chain of FFI nucleation points along the sample edge and their development into self-organized Josephson-like junctions (vortex rivers). In addition, our results offer insights into the applicability of widely used FFI models and suggest Nb-C to be a good candidate material for fast single-photon detectors.
A
bstract
In this work we presented a number of explicit examples for the cubic vertices describing an interaction of massless spin-
5
2
field with massive boson and fermion including all ...hypertransformations necessary for the vertices to be gauge invariant. Here we restrict ourselves with the massive bosons with spins
s
= 2, 1, 0 and massive fermions with spins
s
=
3
3
,
1
2
. Our general analysis predicted that the vertex must exist for any boson and fermion with the spin difference
3
2
or
1
2
. And indeed it appeared that the vertex exists for all six possible pairs (2, 1, 0) ⊗ (
3
2
,
1
2
). As in the case of massive supermultiplets, our construction is based on the gauge invariant description for the massive fields with spins
s
≥ 1. Moreover, we have explicitly checked that all the vertices are invariant also under the gauge symmetries of these massive fields.
In December 2019, coronavirus disease (COVID-19) emerged in Wuhan. However, the characteristics and risk factors associated with disease severity, unimprovement and mortality are unclear and our ...objective is to throw some light on these.
All consecutive patients diagnosed with COVID-19 admitted to the Renmin Hospital of Wuhan University from January 11 to February 6, 2020, were enrolled in this retrospective cohort study.
A total of 663 COVID-19 patients were included in this study. Among these, 247 (37.3%) had at least one kind of chronic disease; 0.5% of the patients (n = 3) were diagnosed with mild COVID-19, while 37.8% (251/663), 47.5% (315/663), and 14.2% (94/663) were in moderate, severe, and critical conditions, respectively. In our hospital, during follow-up 251 of 663 patients (37.9%) improved and 25 patients died, a mortality rate of 3.77%. Older patients (>60 years old) and those with chronic diseases were prone to have a severe to critical COVID-19 condition, to show unimprovement, and to die (p <0.001, <0.001). Multivariate logistic regression analysis identified being male (OR = 0.486, 95%CI 0.311–0.758; p 0.001), having a severe COVID-19 condition (OR = 0.129, 95%CI 0.082–0.201; p <0.001), expectoration (OR = 1.796, 95%CI 1.062–3.036; p 0.029), muscle ache (OR = 0.309, 95%CI 0.153–0.626; p 0.001), and decreased albumin (OR = 1.929, 95%CI 1.199–3.104; p 0.007) as being associated with unimprovement in COVID-19 patients.
Male sex, a severe COVID-19 condition, expectoration, muscle ache, and decreased albumin were independent risk factors which influence the improvement of COVID-19 patients.
A
bstract
In this paper we consider massless spin 2 interacting with the massive arbitrary spin fermions in
d
= 3. First of all, we study all possible deformations for the massive fermion unfolded ...equations in presence of a massless spin-2 field. We find three linearly independent solutions one of which corresponds to the standard gravitational interactions. Then for all three cases we reconstruct appropriate Lagrangian formulation.
A
bstract
We construct a range of supersymmetric cubic vertices for three massless higher spin supermultiplets in the four-dimensional space. We use frame-like multispinor formalism, which allows to ...avoid most of the technical difficulties and provides a uniform description for bosons and fermions. Our work is based on the so-called Fradkin-Vasiliev formalism for construction of the cubic vertices, which requires the non-zero cosmological constant. Thus we first construct the vertices in AdS space and then consider the flat limit. We show that the AdS supersymmetric vertex is a sum of four elementary vertices for supermultiplet components, while one of the vertices vanishes in the flat limit in agreement with the Metsaev’s classification.
Elastic
pp
scattering at LHC energies is treated in additive quark model together with Pomeron exchange theory. The obtained results are compared with the new experimental data on the ratio of real ...to imaginary part of the scattering amplitude at the small transverse momenta
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Contemporary scientific literature on electrochemical supercapacitors is reviewed. The electrochemical supercapacitors are fast-rechargeable energy storage devices. They are classified as ...electrical-double-layer capacitors based on the recharging of the electric double layer; pseudocapacitors, and hybrid capacitors. The electrochemical supercapacitors are used in devices of pulse technology, for electrical energy accumulation, for starting and recuperation of the braking energy in internal combustion engines; for smoothing out peak loads in electrical networks and in numerous portable devices. The electrochemical supercapacitors are subdivided into those of power type and energy type. The power-type (pulsed) supercapacitors have high specific power (~up to 100 kW/kg); the energy-type ones, high specific energy (~up to 25 W h/kg). Compared to batteries, the power-type supercapacitors have a much higher power density and cyclability, up to hundreds of thousands and even million cycles. The electrical-double-layer supercapacitors are also used in the capacitive water deionization devices for water desalination.
The decomposition of large unitary matrices into smaller ones is important because it provides ways to the realization of classical and quantum information processing schemes. Today, most of the ...methods use planar meshes of tunable two-channel blocks; however, the schemes turn out to be sensitive to fabrication errors. We study a novel decomposition method based on multichannel blocks. We have shown that the scheme is universal even when the block's transfer matrices are chosen at random, making it virtually insensitive to errors. Moreover, the placement of the variable elements can be arbitrary, so that the scheme is not bound to specific topologies. Our method can be beneficial for large-scale implementations of unitary transformations by techniques, which are not of wide proliferation today or have yet to be developed.
A
bstract
In this paper we construct a number of cubic interaction vertices for massless bosonic and fermionic higher spin fields in flat four dimensional space. First of all, we construct these ...cubic vertices in
AdS
4
space using a so-called Fradkin-Vasiliev approach, which works only for the non-zero cosmological constant. Then we consider a flat limit taking care on all the higher derivative terms which FV-approach generates. We restrict ourselves with the four dimensions because this allows us to use the frame-like multispinor formalism which greatly simplifies all calculations and provides a description for bosons and fermions on equal footing.
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