Radiophysics and Quantum Electronics最新文献

{"title":"Simulation of Nonlinear Processes in High-Q Microresonators in the Self-Injection Locking Regime with Account of Thermal Effects","authors":"V. I. Pavlov,&nbsp;N. M. Kondratiev,&nbsp;V. E. Lobanov","doi":"10.1007/s11141-023-10283-7","DOIUrl":"10.1007/s11141-023-10283-7","url":null,"abstract":"<p>The thermal effects appearing inevitably when laser radiation propagates through high-Q optical microresonators lead to various drifts, fluctuations and unstable regimes. In particular, thermal effects can affect strongly the generation of optical frequency combs and dissipative soliton structures. A way to offset the thermal effects is to use the self-injection effect that locks the laser radiation frequency to the eigenfrequency of the microresonator. In this work we consider the principles and dynamics of the self-injection locking effect at high pump powers in the nonlinear regimes, including those induced by thermal nonlinearity.</p>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 2-3","pages":"157 - 166"},"PeriodicalIF":0.8,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Influence of Microbubbles on the Turbulence Induced by a Surface Wave","authors":"O. A. Druzhinin","doi":"10.1007/s11141-023-10279-3","DOIUrl":"10.1007/s11141-023-10279-3","url":null,"abstract":"<p>We use the direct numerical simulation (DNS) method to study the vortex structure of the near-surface water layer, which is saturated with air bubbles, in the presence of a stationary surface wave. A wave with a wavelength of 15 cm and a steepness of 0.2 (an amplitude of about 0.5 cm) and bubbles 400 μm in diameter (microbubbles) are considered. Complete three-dimensional fluid motion equations (Navier–Stokes equations) are solved by the DNS method simultaneously with the equations of motion of individual bubbles with allowance for their influence on the carrier flow. Under the influence of the surface wave, the flow in the near-surface layer becomes turbulent and characterized by the presence of vortex structures stretched along the wave propagation direction. To analyze the vortex structure of the flow, the instantaneous velocity gradient tensor is calculated, and its complex eigenvalues, whose imaginary part characterizes the local vorticity of the flow, are calculated, while filtering out the contribution of the purely shear component (vortex sheet). Average profiles of the eigenvalues and the fluctuations, which are obtained at the stage of the statistically stationary flow, show that the influence of the bubbles lead to intensification of small-scale vortices and turbulent pulsations in water.</p>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 2-3","pages":"109 - 115"},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138685952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Stretching of Mesoscale Vortices into Filaments and their Distribution over the Ocean Surface","authors":"V. V. Zhmur,&nbsp;T. V. Belonenko,&nbsp;E. V. Novoselova,&nbsp;B. S. Suetin","doi":"10.1007/s11141-023-10278-4","DOIUrl":"10.1007/s11141-023-10278-4","url":null,"abstract":"<p>We consider various aspects of interaction of vortices with a barotropic flow. When a vortex interacts with a flow, there exist three variants of the flow-core behavior: rotation, nutational oscillations, and unlimited stretching. In the first two cases, the vortex remains a localized formation, such that the ellipse semiaxes undergo oscillations near certain average values. In the third case, the shape of the vortex varies as follows: one horizontal axis increases indefinitely and the second horizontal axis tends to zero so that the vertical size of the vortex does not change and the vortex itself stretches into a filament in top view, remaining ellipsoidal. As a result, vortex formations, which are called filaments, emerge in the ocean. They emerge from the vortices which are initially almost circular in the horizontal plane and represent structures stretched in one direction and having nonzero vorticity. In this work, an analytical and graphical method for determining the regimes of behavior of three-dimensional ellipsoidal vortices is proposed for the first time for an inhomogeneous horizontal current which is linear with respect to the horizontal coordinates. Conditions for inevitable stretching of the vortices into filaments are studied. It is established that the vortex stretching is manifested in spots (domains) on 60–67% of the world ocean surface and the characteristic dimensions of these spots amount to about 200 km. The vortex stretching into filaments ensures energy pumping from mesoscale processes to submesoscale ones. According to the global oceanic reanalysis GLORYS12V1, the domain distributions in the World Ocean are plotted. It is shown that irrespective of the spatial-averaging scales, the integral area of regions in which the mesoscale vortices can stretch into filaments is dominant.</p>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 2-3","pages":"93 - 108"},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two Ways to Generalize Gerstner Waves in the Theory of Waves in Deep Water","authors":"A. A. Abrashkin,&nbsp;E. N. Pelinovsky","doi":"10.1007/s11141-023-10280-w","DOIUrl":"10.1007/s11141-023-10280-w","url":null,"abstract":"<p>By convention, water waves are studied under the assumption of their potentiality. This approximation is not always valid in natural conditions. The vorticity is introduced by shear currents, which are ubiquitous in the ocean. It is also generated in the near-surface layer as a result of wind action. When these factors are taken into account, the models developed for potential waves require refinement and generalization. This paper is devoted to a review of advances in the field of analytical description of surface vortical waves in deep water. The presentation is based on the Lagrangian approach. The focus is on the Gerstner wave, a particular exact solution of the Euler equation. Two ways of its generalization are discussed. The first suggests consideration of weakly nonlinear steady waves with a more general vorticity distribution (Gouyon waves). The second way is to construct exact solutions for waves with inhomogeneous and non-stationary pressure distribution on a free surface (generalized Gerstner waves).</p>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 2-3","pages":"116 - 128"},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138685824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear and Nonlinear Aspects of Climate Response to External Forcings","authors":"A. V. Eliseev","doi":"10.1007/s11141-023-10277-5","DOIUrl":"10.1007/s11141-023-10277-5","url":null,"abstract":"<p>The main role in the current climate change is played by anthropogenic forcings, primarily anthropogenic emissions of greenhouse gases and aerosols. On the global scale, the response of the Earth system to these forcings is close to linear. In particular, it depends mostly on the magnitude of such forcings and only weakly on their nature and spatial localization. However, even with relatively small (in absolute value) external forcings, the response of the characteristics of the Earth system can be essentially nonlinear with the manifestation of tipping points, upon transition through which the behavior of the Earth’s climate changes qualitatively. Examples are given for linear and nonlinear mechanisms of the climate response to external forcings.</p>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 2-3","pages":"79 - 92"},"PeriodicalIF":0.8,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138686061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemodynamic instability in the immediate postoperative setting after transcarotid artery revascularization.","authors":"Thomas A Kania, Aaquib Noorani, Amandeep Juneja, Seleshi Demissie, Kuldeep Singh, Jonathan Deitch, Yana Etkin, Gregg S Landis, Jonathan Schor","doi":"10.1177/17085381221105178","DOIUrl":"10.1177/17085381221105178","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;Transcarotid artery revascularization (TCAR) is a relatively recent development in the management of carotid artery occlusive disease, the utilization of which is becoming more prevalent. This study aims to evaluate the timing, prevalence, and types of hemodynamic instability after TCAR.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;We performed a retrospective review of all TCAR procedures performed at two tertiary care academic medical centers within a single hospital system from 2017 through 2019. Demographics, comorbidities, preoperative patient factors, procedural details, and postoperative data were collected. Patients were assessed over 24 hours postoperatively for stroke, death, myocardial infarction (MI), and hemodynamic instability at 3, 6, 9, 12, and 24 hour intervals. Hemodynamic instability was defined as any vital sign abnormality which required pharmacological intervention with antihypertensive, vasopressor, and/or anti-arrhythmic agents. The incidence and timing of postoperative complications and hemodynamic instability were recorded.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;During the study period, 76 patients 80 TCAR procedures. Out of 80 procedures, 64 (80.0%) were receiving home antihypertensive medication and 28 (35.0%) were symptomatic lesions preoperatively. Intraoperatively, one patient (1.3%) received atropine, 26 (32.5%) received glycopyrrolate, 76 (95%) underwent predilatation, and 16 (20.0%) underwent postdilatation. Postoperatively, a total of 22 cases (27.5%) required medication for acute control of blood pressure or heart rate, which reached a peak of 19 patients (23.8%) within the first 3 hours, and tapered to nine patients (11.3%) by the 24 hour mark. A total of three patients (3.75%) required initiation of pharmacological management after the three-hour mark. Six patients (7.5%) underwent stroke code workup, 4 (5.0%) of whom were confirmed to have stroke on CT. Average time to neurologic event was 3.9 hours. No patients experienced MI or death. Median ICU and hospital days for unstable patients were two and three, respectively, compared to one and one for stable patients.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Hemodynamic instability is common after TCAR and reliably presents at or before postoperative hour 3. Hypo- followed by hyper-tension were the most common manifestations of hemodynamic instability. Regardless, unstable patients and stroke patients were more likely to require longer periods of time in the ICU and in the hospital overall. This may have implications for postoperative ICU resource management when deciding to transfer patients out of a monitored setting. Further study is required to establish relationships between pre- and intra-operative risk factors and outcomes such as hemodynamic instability and/or stroke. At present, one should proceed with careful evaluation of preoperative medications, strict management of postoperative hemodynamics, and clear communication among team members should ","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"11 2","pages":"1151-1160"},"PeriodicalIF":1.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41303667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Barrel Gyrotron for DNP/NMR Spectroscopy","authors":"V. E. Zapevalov,&nbsp;A. S. Zuev,&nbsp; O.P.Plankin,&nbsp;E. S. Semenov","doi":"10.1007/s11141-023-10270-y","DOIUrl":"10.1007/s11141-023-10270-y","url":null,"abstract":"<div><div><p>We consider an example of implementation of a multi-barrel gyrotron. The simplest scheme of the multi-barrel gyrotron combines the advantages of both the canonical gyrotron and the gyrotron with the near-axis beam as the system of formation of helical electron beams and efficient selection of modes synchronous with high gyrofrequency harmonics, respectively, and is attractive from the viewpoint of applications that require moderate power levels. The design of a multi-barrel gyrotron with the possibility of simultaneous generation at frequencies of 263, 395, and 526 GHz is presented. Additionally, the possibility of generating the radiation at a frequency of 594 GHz is considered. Such frequencies are required for DNP/NMR facilities with proton Larmor frequencies of 400, 600, 800, and 900 MHz, respectively. Along with the conventional scheme of radiation output towards the collector, the features of the scheme with the radiation output toward the electron gun are considered.</p></div></div>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 1","pages":"1 - 18"},"PeriodicalIF":0.8,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to: Pulses of the Electromagnetic Field with a Non-Zero Electric Area","authors":"A. B. Plachenov,&nbsp;N. N. Rosanov","doi":"10.1007/s11141-023-10275-7","DOIUrl":"10.1007/s11141-023-10275-7","url":null,"abstract":"","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 1","pages":"77 - 77"},"PeriodicalIF":0.8,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coulomb and Quantum Interference Effects in the Spectra of High-Order Harmonics Generated by Aligned Molecules","authors":"A. D. Slyusareva,&nbsp;M. Yu. Emelin,&nbsp;A. S. Emelina,&nbsp;M. Yu. Ryabikin","doi":"10.1007/s11141-023-10274-8","DOIUrl":"10.1007/s11141-023-10274-8","url":null,"abstract":"<div><div><p>We study theoretically the features of the spectra of high-order harmonics of laser radiation generated in an ensemble of aligned diatomic molecules outside the framework of the strong-field approximation. The studies were carried out on the basis of numerical calculations within the framework of a model given by a two-center generalization of the Yukawa potential. Influence of the interference of contributions from different electron trajectories and the ion core potential on the accuracy of extracting spectroscopic information about the state of the nuclear subsystem of a molecule using high temporal resolution nonlinear spectroscopy based on the analysis of multicenter effects in the spectra of high-order harmonics has been explored.</p></div></div>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 1","pages":"52 - 62"},"PeriodicalIF":0.8,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excitation of Electromagnetic Oscillations of a Dielectric Ball by a Complex Oscillation of a Radial Dipole","authors":"G. F. Zargano,&nbsp;A. V. Kharlanov","doi":"10.1007/s11141-023-10272-w","DOIUrl":"10.1007/s11141-023-10272-w","url":null,"abstract":"<div><div><p>We consider excitation of electromagnetic oscillations of a homogeneous dielectric ball by a radial dipole, oscillations forming a periodic sequence of radio pulses. It is shown that at high frequencies the field distribution is close to the field distribution of the eigenoscillations corresponding to these frequencies, whereas the neighboring harmonics also have an impact at low frequencies. It is also shown that an action at low frequencies characterized by a low Q-factor is needed for exciting short radio pulses in the resonator.</p></div></div>","PeriodicalId":748,"journal":{"name":"Radiophysics and Quantum Electronics","volume":"66 1","pages":"29 - 38"},"PeriodicalIF":0.8,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}