Equation-of-state Dependence of Gravitational Waves in Core-collapse Supernovae

Gravitational waves (GWs) provide unobscured insight into the birthplace of neutron stars and black holes in core-collapse supernovae (CCSNe). The nuclear equation of state (EOS) describing these dense environments is yet uncertain, and variations in its prescription affect the proto−neutron star (PNS) and the post-bounce dynamics in CCSN simulations, subsequently impacting the GW emission. We perform axisymmetric simulations of CCSNe with Skyrme-type EOSs to study how the GW signal and PNS convection zone are impacted by two experimentally accessible EOS parameters, (1) the effective mass of nucleons, m ⋆, which is crucial in setting the thermal dependence of the EOS, and (2) the isoscalar incompressibility modulus, K sat. While K sat shows little impact, the peak frequency of the GWs has a strong effective mass dependence due to faster contraction of the PNS for higher values of m ⋆ owing to a decreased thermal pressure. These more compact PNSs also exhibit more neutrino heating, which drives earlier explosions and correlates with the GW amplitude via accretion plumes striking the PNS, exciting the oscillations. We investigate the spatial origin of the GWs and show the agreement between a frequency-radial distribution of the GW emission and a perturbation analysis. We do not rule out overshoot from below via PNS convection as another moderately strong excitation mechanism in our simulations. We also study the combined effect of effective mass and rotation. In all our simulations we find evidence for a power gap near ∼1250 Hz; we investigate its origin and report its EOS dependence.

Droop-free amplified red emission from Eu ions in GaN

Eu-doped GaN (GaN:Eu) are novel candidates for red light-emitting diodes (LEDs). To further improve the luminescent efficiency of the GaN:Eu-based LED, the efficiency-droop under strong excitation conditions should be suppressed. In this paper, we demonstrate droop-free luminescence of GaN:Eu emitted from a sample-edge using a stripe excitation configuration. The Eu emission intensity clearly increases compared to the conventional surface-emission, and the enhancement is more pronounced for stronger excitation conditions. We clarify that the wavelength dependence of the enhancement agrees well with the optical gain spectrum of the GaN:Eu and is attributed to amplified spontaneous emission.

Multi-functional feedforward inhibitory circuits for cortical odor processing

Feedforward inhibitory circuits are key contributors to the complex interplay between excitation and inhibition in the brain. Little is known about the function of feedforward inhibition in the primary olfactory (piriform) cortex. Using in vivo two-photon targeted patch clamping and calcium imaging in mice, we find that odors evoke strong excitation in two classes of interneurons – neurogliaform (NG) cells and horizontal (HZ) cells – that provide feedforward inhibition in layer 1 of the piriform cortex. NG cells fire much earlier than HZ cells following odor onset, a difference that can be attributed to the faster odor-driven excitatory synaptic drive that NG cells receive from the olfactory bulb. As a consequence, NG cells strongly but transiently inhibit odor-evoked excitation in layer 2 principal cells, whereas HZ cells provide more diffuse and prolonged feedforward inhibition. Our findings reveal unexpected complexity in the operation of inhibition in the piriform cortex.

Magnitude Scales for Marsquakes Calibrated from InSight Data

ABSTRACT In preparation for the National Aeronautics and Space Administration Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) Discovery Program mission, Böse et al. (2018) calibrated magnitude scales for marsquakes that incorporated prelaunch knowledge of Mars’ interior structure and the expected ambient and instrumental noise. Now, using data collected during the first two years after the successful deployment of the InSight very-broadband seismometer on the Martian surface, we revise these relations to account for the seismic and noise characteristics observed on Mars. The data collected so far (until 12 October 2020) include 485 seismic event detections and suggest that (1) marsquakes are characterized by energy between ∼0.1 and 10 Hz; (2) whereas first arriving P- and S-wave phases are regularly identified and assigned, both surface waves and secondary phase arrivals are extremely challenging to identify; (3) the majority of identified events include a strong excitation of an unexpected 2.4 Hz ground resonance; and (4) so-called high-frequency (HF) events exist that are visible mainly as guided Pg/Sg wave trains. In view of these observations, we update our scaling relations for the spectral and body-wave magnitudes, Mw,specMa, mbMa, and mbSMa, and introduce a new magnitude scale, M2.4Ma, for HF events. We use these scales to determine that the magnitudes of events in the current InSight version 5 catalog range between 1.1 and 3.7, with event-specific uncertainties σM ranging from 0.2 to 0.4. Because of the currently unclear interpretation of HF events, magnitude estimates for these events primarily serve as a relative comparison.

Approximate Solutions for the Ion-Laser Interaction in the High Intensity Regime: Matrix Method Perturbative Analysis

We provide an explicit expression for the second-order perturbative solution of a single trapped-ion interactingwith a lser field in the strong excitation regime. From the perturbative analytical solution, based on a matrix methodand a final normalization of the perturbed solutions, we show that the probability to find the ion in its excited statefits well with former results.

Planar Nonlinear Galloping of Iced Transmission Lines under Forced Self-Excitation Conditions

In order to study the influence of dynamic wind on the nonlinear galloping characteristics of iced transmission lines, an external excitation load is added to the governing equation of iced transmission lines under the condition of stable wind, and a new forced self-excited system has been established. The frequency-amplitude relationship of the forced self-excited system under weak excitation and strong excitation is obtained by using the multiple-scale method. The principal resonances and superharmonic and subharmonic resonances of the forced self-excited system have also been analyzed. The results show that, in the forced self-excited system under strong excitation, when the excitation frequency is close to the integral and fractional times of the natural frequency, it is easier to produce 1/2-order subharmonic resonance, 2-order superharmonic resonance, and 3-order superharmonic resonance. In addition, numerical techniques provide bifurcation diagrams of different control parameters, which are able to highlight the effects of the simultaneous presence of the sources of excitation. When the control parameters (wind velocity, excitation amplitude, tuning parameter, tension, and Young’s modulus) change, the response amplitudes of the principal resonance and harmonic resonance will have multivalues, jump phenomenon, and hardening behavior. The control parameters can be used as a reference for engineering design. More importantly, as a combination of the Duffing equation and the Rayleigh equation, the forced self-excited system also has high theoretical research value.

Features of psychological training of athletes for competitive activity in strength sports

The article emphasizes that the psychological preparation of athletes to participate in competitive activities is a complex process of sports improvement. Emphasis is placed on the athlete's ability to overcome unexpected obstacles, to control himself, to quickly assess the situation, make decisions and implement them. The main measures of general and special psychological training and mechanisms of psychological protection against negative actions during competitions of athletes specializing in power sports are analyzed. It is noted that in power sports the conditions in which competitions take place differ from the conditions of training sessions. Coaches and psychologists should train athletes not only physically and tactically, but also develop their ability to withstand many pre-competitive and competitive factors that have a disorganizing effect and cause a mismatch of functions, ie reduce reliability in competitive activities. It is determined that the main components of achieving results in strength sports are: physical shape, technical and psychological training. Preparation for the start can be carried out at low energy consumption or, conversely, at high power consumption in a state of strong excitation. These differences in intensity can be assessed as follows: from a purely subjective point of view - then talk about the degree of immersion in preparation for the activity; from an objective point of view - then it is necessary to determine the level of nervous and somatic functioning, which underlies the state of readiness of the athlete. In this context, we should consider the concept of activation, which simultaneously means a rapid increase in the activity of the central nervous system, and the resulting intensification of peripheral processes. It is indisputable that the more extreme the competition, the more intense the athlete's mechanisms of activation of mental and physiological functions, which directly affect the effectiveness of performance. Moreover, this happens in an arbitrary (or even involuntary) mode. Before the responsible start the installation connected with expectation of the most probable result of competitions is formed. Often the installation is formed on an unconscious level, but the more complex in its structure is the future activit y, the more in the formed formation is dominated by conscious, volitional components.

Luminescent Ionogels with Excellent Transparency, High Mechanical Strength, and High Conductivity

The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf2]) within an organic–inorganic hybrid host. The organic–inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic–organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO2. Both the thermal stability and mechanical strength of the ionogel significantly increased by the addition of IL. The immobilization of [Bmim][NTf2] within the ionogel provided the final ionogel with an ionic conductivity as high as ca. 0.04 S cm−1 at 50 °C. Moreover, the hybrid ionogel can be modified with organosilica-modified carbon dots within the network to yield a transparent and flexible ionogel with strong excitation-dependent emission between 400 and 800 nm. The approach is, therefore, a blueprint for the construction of next-generation multifunctional ionogels.

Quantum Paradigm of the Foldover Magnetic Resonance

The explosive development of quantum magnonics requires considering several previously known effects from a new angle. In this article, we revise the phenomenon of "foldover" (bi-stable) magnetic resonance from the point of view of quantum magnonics. The density of magnons under strong excitation can exceed the critical value for the formation of a magnon Bose condensate. Under these conditions, the effect of quantum transport of magnons should be considered. In particular, the effect of spin superfluidity, discovered earlier in super fluid 3He should lead to spatial redistribution of the precessing magnetization. Our experimental results confirm a significant change in properties of the foldover magnetic resonance in yttrium iron garnet (YIG) due to superfluid magnetization transport. This discovery paves the way for many quantum applications of supermagnonics, such as magnetic Josephson effect, long-distance spin transport, Q-bit, quantum logics, magnetic sensors, and others.