We predict a new class of three-dimensional (3D) topological dissipative optical one-component solitons in homogeneous laser media with fast saturable absorption. Their skeletons formed by vortex ...lines where the field vanishes are tangles, i.e., N_{c} knotted or unknotted, linked or unlinked closed lines and M unclosed lines that thread all the closed lines and end at the infinitely far soliton periphery. They are generated by embedding two-dimensional laser solitons or their complexes in 3D space after their rotation around an unclosed, infinite vortex line with topological charge M_{0} (N_{c}, M, and M_{0} are integers). With such structure propagation, the "hula-hoop" solitons form; their stability is confirmed numerically. For the solitons found, all vortex lines have unit topological charge: the number of closed lines N_{c}=1 and 2 (unknots, trefoils, and Solomon knots links); unclosed vortex lines are unknotted and unlinked, their number M=1, 2, and 3.
For three-dimensional tangle laser solitons that have a number of unclosed and closed vortex lines and coexist in a range of the scheme parameters, we predict irreversible hysteretic transformation ...of their internal structure when a system parameter slowly and regularly varies crossing the boundary of the stability of one or another soliton. During the hysteresis cycle, when restoring the initial parameter value, the soliton topology simplifies (decrease of topological indices), its field energy decreases, and the energy of the medium increases. The transient includes a series of elementary reactions: reconnection of vortex lines, separation of closed vortex loops after strong bending of a parent vortex line, and twist of unclosed vortex lines changing topological indices. During the transient, new (metastable) types of localized topological structures arise. It is shown that the tangent energy flow along closed vortex lines is unidirectional or direction alternating.
We predict and study a new type of three-dimensional soliton: asymmetric rotating and precessing stable topological-dissipative-optical localized structures in homogeneous media with saturable ...amplification and absorption. The crucial factor determining their dynamics is the ratio of the diffusion coefficients characterizing the frequency dispersion and angular selectivity (dichroism) of the scheme. These vortex solitons exist and are stable for overcritical values of the selectivity coefficients and can be realized in lasers of large sizes with saturable absorption.
An analysis was made of the field structures in a coaxial laser with fast saturable absorption. In such an efficiently one-dimensional scheme, the integer topological index (charge) naturally arises: ...the phase incursion of the field envelope when bypassing the aperture, divided by 2π. The topological charge is the winding number for the phase curve introduced for the electric field envelope with increase of the coordinate for fixed time. In the framework of the generalized Ginzburg-Landau equation, shown are finite numbers of plane-wave modes, stable with respect to weak perturbations, and solitonlike modes with inhomogeneous intensity distributions and different topological charge. It was found that the topological charge could change during transient to steady state. The events of these changes alternate with formation of cusps of the phase curve occurring when extrema of the field intensity and phase coincide.
Enzymes of the phospholipase superfamily are involved in lipid metabolism, as well as regulation of membrane composition, cell signaling, and inflammation. This review provides an insight into the ...structure, functional properties, and biotechnological application of phospholipase A2 and phospholipases in general.
Recent advances in DNA sequencing open prospects to make whole-genome analysis rapid and reliable, which is promising for various applications including personalized medicine. However, existing ...techniques for de novo genome assembly, which is used for the analysis of genomic rearrangements, chromosome phasing, and reconstructing genomes without a reference, require solving tasks of high computational complexity. Here we demonstrate a method for solving genome assembly tasks with the use of quantum and quantum-inspired optimization techniques. Within this method, we present experimental results on genome assembly using quantum annealers both for simulated data and the Formula: see textX 174 bacteriophage. Our results pave a way for a significant increase in the efficiency of solving bioinformatics problems with the use of quantum computing technologies and, in particular, quantum annealing might be an effective method. We expect that the new generation of quantum annealing devices would outperform existing techniques for de novo genome assembly. To the best of our knowledge, this is the first experimental study of de novo genome assembly problems both for real and synthetic data on quantum annealing devices and quantum-inspired techniques.
The Central Yakutian permafrost landscape is rapidly being modified by land use and global warming, but small‐scale thermokarst process variability and hydrological conditions are poorly understood. ...We analyze lake‐area changes and thaw subsidence of young thermokarst lakes on ice‐complex deposits (yedoma lakes) in comparison to residual lakes in alas basins during the last 70 years for a local study site and we record regional lake size and distribution on different ice‐rich permafrost terraces using satellite and historical airborne imagery. Statistical analysis of climatic and ground‐temperature data identified driving factors of yedoma‐ and alas‐lake changes. Overall, lake area is larger today than in 1944 but alas‐lake levels have oscillated greatly over 70 years, with a mean alas‐lake‐radius change rate of 1.6 ± 3.0 m/yr. Anthropogenic disturbance and forest degradation initiated, and climate forced rapid, continuous yedoma‐lake growth. The mean yedoma lake‐radius change rate equals 1.2 ± 1.0 m/yr over the whole observation period. Mean thaw subsidence below yedoma lakes is 6.2 ± 1.4 cm/yr. Multiple regression analysis suggests that winter precipitation, winter temperature, and active‐layer properties are primary controllers of area changes in both lake types; summer weather and permafrost conditions additionally influence yedoma‐lake growth rates. The main controlling factors of alas‐lake changes are unclear due to larger catchment areas and subsurface hydrological conditions. Increasing thermokarst activity is currently linked to older terraces with higher ground‐ice contents, but thermokarst activity will likely stay high and wet conditions will persist within the near future in Central Yakutian alas basins.
Key Points:
Remote sensing, field, and statistical analysis of thermokarst‐lake change in relation to long‐term climate records and geomorphology
Type and degree of climatic and geomorphological influence depend on lake type, size, origin, and evolution
Thermokarst activity will remain at a high level and wet conditions within alas basins will persist in the near future
In the summer of 2021, a federal law concerning the regulation of greenhouse gas emissions appeared in the Russian Federation - Federal Law No. 296 dated 02.07.2021 "On Limitation of Greenhouse Gas ...Emissions". The law defines the basis of legal regulation of relations in the sphere of activities accompanied by greenhouse gas emissions and carried out on the territory of Russia, as well as on the continental shelf, in the exclusive economic zone of the Russian Federation, in the Russian sector of the Caspian Sea. The law on limiting greenhouse gas emissions introduces the following concepts: (a) greenhouse gases; (b) climate projects; (c) carbon units; (d) carbon footprint as the total volume of greenhouse gas emissions and their absorption in the course of production/provision of a service.
The concept of hydrogen civilization, the foundations of which were laid by the romanticist and pioneer of the Hydrogen Era, Prof. T.N. Vesiroglu, attracts attention of more and more scientists and engineers.The hydrogen civilization will require a significant amount of hydrogen for its implementation. For the current stage of development of civilization, the volume of hydrogen generated annually must be at least 560 million tons.
The most interesting is the combination of renewable and environmentally friendly non-renewable energy sources to obtain the universal energy carrier hydrogen (Concept of alternative energy and ecology, A.L. Gusev and T.N. Veziroglu, 2000). In particular, wind-hydrogen energy is of great interest as a promising area of innovation in the field of energy at remote sites.
The hydrogen civilization will require a significant amount of hydrogen for its implementation. For the current stage of development of civilization, the volume of hydrogen generated annually must be at least 560 million tons.
Wind-hydrogen energy can make a great contribution to the implementation of the hydrogen energy concept. It is important that power supply to remote areas requires significant financial costs, and wind energy in this regard is the optimal solution. Thus, the cost of 1 km of power line can range from 20 to 50,000 euros. For remote sites, the cost of creating such a line, as well as the cost of its maintenance in harsh climates, will be extremely high. At the same time, the cost of a wind turbine is equal to the cost of 1 km of power line, and its service life can reach 30 years.
However, to optimize the use of wind turbines and wind-hydrogen power plants, it is important to take into account the emission of pollutants into the atmosphere during the production of elements of wind power plants and wind-hydrogen power plants (WPP).
The article outlines the main provisions of a new method for determining emissions of pollutants during the life cycle of wind power plants (wind farms) using aggregated indicators. The rationale for the use of aggregated indicators is given. An algorithm is described for determining emissions of pollutants CO2eq (carbon dioxide), SO2eq (sulfur dioxide) and PO4eq (phosphates) during the production of elements of wind turbines and wind farms. The results of calculations of emissions of CO2eq, SO2eq and PO4eq during the life cycle for onshore wind farms (Cossack wind farm and Arkhangelsk wind farm) with an installed capacity of 100 and 340 MW are presented and the environmental effect of their use is determined. Calculated emissions of pollutants, which can be prevented when choosing the wind farms as power sources and determined the environmental effect of their use when comparing with thermal power plants.
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