The excitation of terahertz plasmon modes in a graphene rectangle by normally incident linearly polarized electromagnetic wave has been theoretically studied. The complete electromagnetic approach ...based on formulation of the integral equations for sought-for electromagnetic quantities has been developed. The influence of edge-field effects on excitation of plasmon modes for different polarization of the incident wave and different shapes of graphene rectangle has been studied. The absorption cross-section spectra and the charge density distributions in graphene rectangle for different plasmon modes have been studied. It has been found that the edge-field effect, which results in spreading the plasmon field beyond the geometric boundaries of graphene rectangle, leads to considerable red shifts of the plasmon mode frequencies and modifies the plasmon mode dispersion.
An original technique for describing excited states of electrons in crystal structure has been considered by an example of lithium. It is shown that the electron spectrum in lithium changes only ...slightly at large values of lattice parameter (up to 8.77 Bohr radii). The lifetimes of excited electrons of external
s
and
p
states differ significantly at lattice parameters
d
< 8.77 Bohr radii. A metastable crystalline state of bcc lithium is found, which barely depends on the excitation power at a lattice constant equal to 6.55 Bohr radii, corresponding to the bcc lattice constant of lithium in the ground state.
Due to their bacterial ancestry, many components of mitochondria share structural similarities with bacteria. Release of molecular danger signals from injured cell mitochondria (mitochondria-derived ...damage-associated molecular patterns, mito-DAMPs) triggers a potent inflammatory response, but their role in fibrosis is unknown. Using liver fibrosis resistant/susceptible mouse strain system, we demonstrate that mito-DAMPs released from injured hepatocyte mitochondria (with mtDNA as major active component) directly activate hepatic stellate cells, the fibrogenic cell in the liver, and drive liver scarring. The release of mito-DAMPs is controlled by efferocytosis of dying hepatocytes by phagocytic resident liver macrophages and infiltrating Gr-1(+) myeloid cells. Circulating mito-DAMPs are markedly increased in human patients with non-alcoholic steatohepatitis (NASH) and significant liver fibrosis. Our study identifies specific pathway driving liver fibrosis, with important diagnostic and therapeutic implications. Targeting mito-DAMP release from hepatocytes and/or modulating the phagocytic function of macrophages represents a promising antifibrotic strategy.
Carbon nanotubes are unique tubular structures of nanometer diameter and large length/diameter ratio. The nanotubes may consist of one up to tens and hundreds of concentric shells of carbons with ...adjacent shells separation of ∼0.34
nm. The carbon network of the shells is closely related to the honeycomb arrangement of the carbon atoms in the graphite sheets. The amazing mechanical and electronic properties of the nanotubes stem in their quasi-one-dimensional (1D) structure and the graphite-like arrangement of the carbon atoms in the shells. Thus, the nanotubes have high Young’s modulus and tensile strength, which makes them preferable for composite materials with improved mechanical properties. The nanotubes can be metallic or semiconducting depending on their structural parameters. This opens the ways for application of the nanotubes as central elements in electronic devices including field-effect transistors (FET), single-electron transistors and rectifying diodes. Possibilities for using of the nanotubes as high-capacity hydrogen storage media were also considered. This report is intended to summarize some of the major achievements in the field of the carbon nanotube research both experimental and theoretical in connection with the possible industrial applications of the nanotubes.
A method of employing semileptonic
-meson decays is proposed. Combined with a time-dependent analysis of decay parameters of initially produced combination, it permits extracting
. These measurements ...could be applied to heavy-flavor physics problems—in particular, charm physics. A feasibility study for the strong-phase difference in charm decays is performed.
We study 6000 author-publication observations to investigate predictors of early career success in six fields of economics. Concentrating on top researchers enables us to control for the effects of ...ability and effort, and focusing on the start of their careers minimizes distortions from reputation feedback. Our results reveal that the most important predictor for early career success is the ranking of an author's PhD granting institution, followed by his first placement. Our insights suggest that a counterfactual decrease in the Alma mater of a high ability author, who graduated from a top 10 university, by as little as 10 to 20 ranks, reduces his probability of getting a top 5 publication significantly by 13 percentage points. Lowering the ranking of his Alma mater by another 80 ranks decreases his chances of getting a top publication by a factor of three. Our findings suggest that the economics publication market values Alma mater signals, discounting newcomers graduating from- or working at lower ranked departments.
We study terahertz (THz) radiation transmission through grating-gate graphene-based nanostructures. We report on room-temperature THz radiation amplification stimulated by current-driven plasmon ...excitation. Specifically, with an increase of the dc current under periodic charge density modulation, we observe a strong redshift of the resonant THz plasmon absorption, followed by a window of complete transparency to incoming radiation and subsequent amplification and blueshift of the resonant plasmon frequency. Our results are, to the best of our knowledge, the first experimental observation of energy transfer from dc current to plasmons leading to THz amplification. Additionally, we present a simple model offering a phenomenological description of the observed THz amplification. This model shows that in the presence of a dc current the radiation-induced correction to dissipation is sensitive to the phase shift between oscillations of carrier density and drift velocity. And, with an increasing current, the dissipation becomes negative, leading to amplification. The experimental results of this work, as all obtained at room-temperature, pave the way toward the new 2D plasmon-based, voltage-tunable THz radiation amplifiers.
The term "critical raw materials" (CRMs) refers to various metals and nonmetals that are crucial to Europe's economic progress. Modern technologies enabling effective use and recyclability of CRMs ...are in critical demand for the EU industries. The use of CRMs, especially in the fields of biomedicine, aerospace, electric vehicles, and energy applications, is almost irreplaceable. Additive manufacturing (also referred to as 3D printing) is one of the key enabling technologies in the field of manufacturing which underpins the Fourth Industrial Revolution. 3D printing not only suppresses waste but also provides an efficient buy-to-fly ratio and possesses the potential to entirely change supply and distribution chains, significantly reducing costs and revolutionizing all logistics. This review provides comprehensive new insights into CRM-containing materials processed by modern additive manufacturing techniques and outlines the potential for increasing the efficiency of CRMs utilization and reducing the dependence on CRMs through wider industrial incorporation of AM and specifics of powder bed AM methods making them prime candidates for such developments.
Photoelectronics Based on 0D Materials Ponomarenko, V. P.; Popov, V. S.; Popov, S. V.
Journal of communications technology & electronics,
12/2022, Letnik:
67, Številka:
Suppl 1
Journal Article
Recenzirano
—
The arrangement and main parameters of the photosensory structures and devices based on quantum dots of the elements of the II, IV, and VI groups of the periodic table made by colloidal chemistry ...methods have been described. The hybrid structural schemes of photoresistive, photodiode, and phototransistor elements with absorbing layers based on the HgTe, HgSe, PbS, and PbSe colloidal quantum dots (CQDs) for operation in various spectral ranges including using 2D materials have been considered.
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