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Demodulation is a key technology for the enhanced Loran (eLoran) system to achieve positioning and timing, and it affects the final performance of the system. Based on the traditional matched correlation algorithm, this paper proposes a new matched correlation demodulation method with notch processing. Furthermore, by combining it with the pattern modulation of the eLoran system, the matched correlation integrate notch demodulation method is further modified to improve demodulation performance. Firstly, the data link of the eLoran system is introduced in detail, including the encoding and modulation processes, the influencing factors of received signals, and the evaluation methods in the demodulation process. Secondly, on the basis of the principle of the matched correlation (MC) demodulation algorithm, a matched correlation demodulation algorithm integrating notch processing (MC-NF) and a demodulation correlation algorithm combined with modulation patterns (PMC-NF) are proposed. And, an analysis of the key factors affecting demodulation performance is given. Next, the demodulation performance of the mentioned algorithms under the conditions of random noise, skywave, and in-band continuous wave interference is calculated in detail. A large number of experimental results show that notch processing performs excellently in suppressing random noise and in-band continuous wave interference, and it can greatly improve the demodulation performance of the traditional matched correlation algorithm. Moreover, PMC-NF is superior to MC-NF; approximately 2.8 dB at decoding the critical point.

Whitecaps in deep water are located near maximum slopes of the interference pattern of dominant wind waves and the most probable breaking waves are those waves that travel with the speed of the component of the interference pattern in the wind direction. These breaking waves are in the wavelength range 1 to 12 m, much shorter than typical dominant waves. The patterns of large steepness caused by interfering dominant waves move at speeds less than the group speed of the dominant wave unless the wave spectrum is narrow in both wavenumber and azimuth. For spectra with wavenumber and azimuth angle spreads representative of those observed on the ocean, the velocity of propagation of the pattern of steep waves in the wind direction is the same as the speed at the maximum of Phillips Λ(c) function, the speed of the peak of HH Doppler spectra, and the speed measured by acoustic event tracking. Key Points Wind‐wave interference patterns do not move at the dominant wave group speed Waves that produce whitecaps in deep water are shorter than dominant waves Peaks of HH Doppler spectra are at the same speed as peaks of Lambda(c)

Interference wave is an important research target in the field of navigation, electromagnetic and earth science. In this work, the nonlinear property of neural network is used to study the interference wave and the bright and dark soliton solutions. The generalized broken soliton-like equation is derived through the generalized bilinear method. Three neural network models are presented to fit explicit solutions of generalized broken soliton-like equations and Boiti–Leon–Manna–Pempinelli-like equation with 100% accuracy. Interference wave solutions of the generalized broken soliton-like equation and the bright and dark soliton solutions of the Boiti–Leon–Manna–Pempinelli-like equation are obtained with the help of the bilinear neural network method. Interference waves and the bright and dark soliton solutions are shown via three-dimensional plots and density plots.

Diffraction in time manifests itself as the appearance of probability-density fringes when a matter wave passes through an opaque screen with abrupt temporal variations of transmission properties. Here we analytically describe the phase-space structure of diffraction-in-time fringes for a class of smooth time gratings. More precisely, we obtain an analytic expression for the Husimi distribution representing the state of the system in the case of time gratings comprising a succession of Lorentzian-like slits. In particular, for a double-slit scenario, we derive a simple and intuitive expression that accurately captures the position of interference fringes in phase space.

A multiple waveguide invariant (β) estimation method based on the warping transform and variational mode decomposition (VMD) from one‐dimensional broadband interference sound intensity (BISI) is presented. Firstly, an average β is estimated based on the low‐rank property of the Hankel matrix constructed by BISI. Secondly, the warping principle is used to transform BISI into a warped one. Thirdly, the conventional VMD can be used to effectively decompose the warped BISI. Finally, multiple β can be estimated, respectively. Traditional β estimation methods are based on a two‐dimensional acoustic interference pattern, whose acquisition depends on the horizontal array. This method reduces the data dimensionality of the multivalued β estimation problem without requiring any environmental prior information and is applicable to single hydrophone scenarios. The effectiveness of the presented method is validated by numerical simulation. A multiple waveguide invariant (β) estimation method based on the warping transform and variational mode decomposition (VMD) from one‐dimensional broadband interference sound intensity is presented. This method is the first to estimate multiple β from one‐dimensional broadband interference sound intensity and has better separation effect than traditional VMD.

Electromagnetic wave interference has escalated into a pervasive global issue, driving intensified research efforts across both civilian and military domains. However, the development of advanced electromagnetic wave (EMW) absorbers with finely tunable dielectric and magnetic loss properties has emerged as a pivotal strategy for mitigating electromagnetic pollution. Herein, we propose a cation engineering strategy to tailor the absorption properties of ZIF-67-derived layered double hydroxide (LDH) composites through systematic substitution of Co2+ with Fe, Mn, Zn, or Ni and stoichiometric control (Co/X = 1:4, 1:1). Mn/Zn doping enhances dipole polarization via lattice distortion, while structural analysis confirms that higher Co/X ratios preserve core–shell architectures, optimizing impedance matching. In contrast, Fe incorporation leads to excessive conductivity and impedance mismatch. The optimized CoNi1-4 composite exhibits superior broadband absorption (EAB = 4.52 GHz at 1.8 mm thickness, RLmin = −24.5 dB), attributed to synergistic interface polarization and magnetic coupling. This study delivers a highly tailorable materials platform that enables a deeper fundamental understanding of the synergy between dielectric and magnetic loss processes, thereby offering new pathways for optimizing electromagnetic wave absorption.

The rocket sled, as a ground dynamic test system, combines the characteristics of the wind tunnel test and the flight test. However, some practical factors, such as shock wave interference, ground effect, and high-intensity aerodynamic noise will cause serious interference and even failure of the uniformly distributed sensors during horizontal sliding in a wide speed range. The AGARD HB-2 standard model is employed as the payload to simulate the aerodynamic and aeroacoustic characteristics during the variable acceleration period, aiming to optimize the test sensors layout. It is observed that in the high Mach number flow fields, strong coupling behaviors among complex waves will occur. The peak of wake vortex strength will appear at 1.5 s and gradually diminish over time. In addition, when the vortex between the load and the booster is monitored, its position shifts forward in the subsonic stage, then gradually moves backward and expands in the supersonic stage. Acoustic directivity is pronounced at subsonic and transonic speeds, pointing towards 75° and 135° relative to the sliding speed, respectively. These results can provide technical support for sensor layout and high-precision testing in rocket sled tests.

Investigating out-of-equilibrium dynamics with two-dimensional (2D) systems is of widespread theoretical interest, as these systems are strongly influenced by fluctuations and there exists a superfluid phase transition at a finite temperature. In this work, we realise matter-wave interference for degenerate Bose gases, including the first demonstration of coherent splitting of 2D Bose gases using magnetic trapping potentials. We improve the fringe contrast by imaging only a thin slice of the expanded atom clouds, which will be necessary for subsequent studies on the relaxation of the gas following a quantum quench.

The (3+1)-dimensional BKP-Boussinesq equation is widely used to describe and understand nonlinear wave phenomena. In this article, a single hidden layer neural network model is constructed using the bilinear neural network method to obtain lump solutions, interaction solutions, and breather solutions of the equation. Based on the single-layer model, a ’4-2-2-1’ neural network model was constructed. By assigning different weight coefficients and thresholds, interference wave solutions and periodic solutions of the equations are obtained. During the solving process, some weight coefficients being zero may lead to the degeneration of the bilinear neural network model, and this phenomenon can be mitigated by appropriately enhancing the model’s performance. Furthermore, the study shows that due to the universal approximation property of neural networks, the bilinear neural network method offers a more flexible and simpler way to solve nonlinear problems. It can yield a greater number of novel analytical solutions and promote the development of the generality of solving nonlinear partial differential equations.