Physics Open最新文献

Here in we report the nanocrystalline Ni_1-xCd_xNd_yFe_2-yO₄ (0 ≤ x ≤ 1.0 in steps of 0.2: y = 0.0; 0.1) ferrites were synthesized by novel solution combustion technique. The sintered powders have been characterized by X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive analysis by x-rays (EDAX) methods. DC electrical conductivity carried out by two probe method. Magnetic parameters were measured using vibrating sample magnetometer with an applied magnetic field up to 15 kOe at 300K. The XRD results confirmed the formation of single phase cubic spinel structure formation. It was found that the lattice parameter increased with increase in Cd²⁺ ion. The crystallite sizes have been found in the range of 44.24 nm–15.467 nm. Moreover, the formation of two prominent absorption bands confirmed the spinel structure. The SEM micrographs evidenced almost spherical shaped, agglomerated and grainy structure of nanoferrites. Moreover, the Curie temperature (T_C) was decreased with increasing temperature and exhibit the semiconducting behaviour. Further, saturation magnetization (M_S), remanence magnetization (M_r); coercivity (H_C) were decrease with increase in the magnetic field. The magnetic parameters; M_S, M_r, n_B increases attain maximum thereafter decreases with increase in Cd²⁺ ion and Nd³⁺ ion content.

Dynamical and statistical behaviour of the ionic particles in dissolved salts have long been known, but their hydration shells still raise unsettled questions. We engineered a “diffusion tunnel diode” that is structurally analogous to the well-known Esaki diode, but now concentration gradients serve as generalized voltages and the current means particle flow. In an equipartition sense, the hydrated ions enter a cavity as individual particles and later, upon increase of their concentration therein, they lose water molecules that henceforth are particles of their own. These temporarily attached water molecules thus are the tunnel current analogue. Unlike the original tunnel diode, our negative differential resistance has implications for the second law of thermodynamics, due to thermal effects of changes in the hydration shells.

An extended version of (3+1)-dimensional non-linear Schrödinger equation that has a cubic–quintic nonlinear component under the stochastic effects is examined in this investigation. Several stochastic exact solutions of this model is acquired through the application of the improved modified extended tanh-function scheme (IMETFS). This method offers a practical and effective approach to finding precise solutions to several kinds of nonlinear partial differential equations. In addition, these solutions include stochastic soliton solutions (bright, singular, combo dark-singular), and exact solution such as singular periodic, Jacobi elliptic function, Weierstrass elliptic doubly periodic solution, rational, and exponential functions. Since it is the first study of its sort to examine multiplicative white noise’s impacts in this particular setting, it offers fresh insights and innovative research approaches for the field’s future studies. The work adds much to our understanding of soliton theory and how it relates to optical fiber technology while illuminating hitherto unknown facets of multiplicative white noise. To illustrate the impact of the noise, a few recovered solutions with varying noise strengths are given graphically as examples.

The cosmological constant is probably the most fundamental aspect of nature’s laws and a deeper understanding of it may be the most direct route to the theory of everything. This research adopts the framework of a basic triangle number harmonic sum of energy-eigenmodes with an important postulate: that cosmologies contain a common energy-eigenmode. This ensures that cosmologies relate to the triangle–square numbers (TSn) and guarantees that the Hubble horizon is an integer multiple of the Planck length. Importantly, this allows a single value to be found in the range of $H_0=\left(\text{50–100}\right)$ km s⁻¹ Mpc⁻¹ for the Hubble constant leading to the anticipated resolution of the tension and a solution to the vacuum catastrophe. Remarkably, the predicted expansion rate $H_0=H_{80}$ (from the inverse of the square root of the 80th triangle–square number) falls within $1\sigma$ of the SH0ES team measurement of $H_0=\text{73.04}\pm \text{1.04}$ km s⁻¹ Mpc⁻¹ (Riess et al., 2022), and more recent estimate of $H_0=\text{73.29}\pm \text{0.90}$ km s⁻¹ Mpc⁻¹ (Murakami et al., 2023). Furthermore, the combinatorics of the prime factors of the square root of the 80th TSn are observed to give a scale hierarchy of the masses of the elementary particles of the standard model to a first-order approximation. Hence, if the postulate is correct, then the cosmological constant $\Lambda$ may be the only kind of matter permeating the universe.

Stochastic optical solitons are a fascinating phenomenon in nonlinear optics where soliton-like behavior emerges in systems affected by stochastic noise. This study investigates the influence of Brownian motion on wave propagation in optical fibers. The propagation is modeled using a stochastic nonlinear Schrödinger equation incorporating quintuple power-law nonlinearity and nonlinear chromatic dispersion. To explore this, the improved modified extended tanh (IMET) scheme, leveraging the extended Riccati equation, is employed. This technique facilitates the extraction of various stochastic solutions, including bright, dark, and singular solitons. Furthermore, solutions in the shapes of exponential, singular periodic, and Weierstrass elliptic forms are investigated. The study looks at how the strength of noise impacts various solutions, and Matlab software is used to create 2D and 3D graphs that show the results. It has been noted that when noise intensity rises, signal level falls and surface flattens.

We demonstrate a compact ion beam device capable of accelerating H⁺ and D⁺ ions up to 75 keV energy, onto a solid target, with sufficient beam current to study fusion reactions. The ion beam system uses a microwave driven plasma source to generate ions that are accelerated to high energy with a direct current (DC) acceleration structure. The plasma source is driven by pulsed microwaves from a solid-state radiofrequency (RF) amplifier, which is impedance matched to the plasma source chamber at the S-band frequency in the range of 2.4–2.5 GHz. The plasma chamber is held at high positive DC potential and is isolated from the impedance matching structure (at ground potential) by a dielectric-filled gap. To facilitate the use of high-energy-particle detectors near the target, the plasma chamber is biased to a high positive voltage, while the target remains grounded. A target loaded with deuterium is used to study D-D fusion and a B₄C or LaB₆ target is used to study p-¹¹B fusion. Detectors include solid-state charged particle detector and a scintillation fast neutron detector. The complete ion beam system can fit on a laboratory table and is a useful tool for teaching undergraduate and graduate students about the physics of fusion.

Xie and Eberly introduced a genuine multipartite entanglement (GME) measure ‘concurrence fill’ (Xie and Eberly, 2021) for three-party systems. It is defined as the area of a triangle whose side lengths represent squared concurrence in each bi-partition. However, it has been recently shown that concurrence fill is not monotonic under LOCC, hence not a faithful measure of entanglement. Though it is not a faithful entanglement measure, it encapsulates an elegant geometric interpretation of bipartite squared concurrences. There have been a few attempts to generalize GME quantifier to four-party settings and beyond. However, some of them are not faithful, and others simply lack an elegant geometric interpretation. The recent proposal from Xie et al.. constructs a concurrence tetrahedron, whose volume gives the amount of GME for four-party systems; with generalization to more than four parties being the hypervolume of the simplex structure in that dimension. Here, we show by construction that to capture all aspects of multipartite entanglement, one does not need a more complex structure, and the four-party entanglement can be demonstrated using 2D geometry only. The subadditivity together with the Araki-Lieb inequality of linear entropy is used to construct a direct extension of the geometric GME quantifier to four-party systems resulting in quadrilateral geometry. Our quantifier can be geometrically interpreted as a combination of three quadrilaterals whose sides result from the concurrence in one-to-three bi-partition, and diagonal as concurrence in two-to-two bipartition.