Modern Physics Letters B

The effect of rare earth element neodymium (Nd) addition on the microstructure and martensitic transformation behavior of Ni${}_{50}$Ti${}_{50-x}$Nd${}_x$ ($x$ = 0, 0.1, 0.3, 0.5 and 0.7 at.%) shape memory alloy was investigated by scanning electronic microscope, X-ray diffraction and differential scanning calorimetry. The results show that the microstructure of Ni–Ti–Nd ternary alloy consists of NiNd phase, NiTi₂ and the NiTi matrix. A one-step martensitic transformation is observed in the alloys. The martensitic transformation temperature Ms increases sharply increasing 0.1–0.7 at.% Nd content is added.

In the current work, we have demonstrated the phase of ZnO by reference to block theory, in which the phase may be considered to show a paramagnetic ordering between block spins, which in turn comprise random spins that have a majority of individual spins in a given direction. By making use of the Curie–Weiss law of block spins for zinc oxide, we obtained the susceptibility for the lower approximation of the Brillouin function and calculated the resistivity. The resistivity of ZnO mainly stems from spin glass-like disorders according to our analysis.

Fluorescent carbon nanoparticles (CNPs) are obtained via pulsed laser ablation (PLA) of a carbon target immersed in deionized water. By tuning the laser power for PLA, the density of oxygen-related functional groups at the surfaces is controllable. While the crystallinities, sizes, morphologies and defects are nearly retained, the prepared CNPs show blue fluorescence under UV exposure and the photoluminescence (PL) intensities of the C-dots are dependent on the oxygen contents. Accordingly, the PL is attributed to the transition of electronic states caused by oxygen-related functional groups. This work sheds new light on the PL mechanism of CNPs and proposes an efficient way to prepare CNPs with controllable oxygen-related functional groups.

The emergence of quantum consciousness stems from dynamic flows of hydrogen ions in brain liquid. This liquid contains vast areas of the fourth phase of water with hexagonal packing of its molecules, the so-called exclusion zone (EZ) of water. The hydrogen ion motion on such hexagonal lattices shows as the hopping of the ions forward and the holes (vacant places) backward, caused by the Grotthuss mechanism. By supporting this motion using external infrasound sources, one may achieve the appearance of the superfluid state of the EZ water. Flows of the hydrogen ions are described by the modified Navier–Stokes equation. It, along with the continuity equation, yields the nonlinear Schrödinger equation, which describes the quantum effects of these flows, such as the tunneling at long distances or the interference on gap junctions.

An arsenic tri-selenide-based strip/slot hybrid waveguide with a single horizontal silica slot is proposed to achieve an extremely low and flat dispersion with three zero dispersion wavelengths. By adjusting the geometrical structural parameters of the hybrid waveguide, dispersion tailoring is fully obtained. The flat group velocity dispersion varying between ±0.08 ps²/(m) is obtained over a 1253 nm bandwidth. The parameters of effective area, nonlinear coefficient, and third-order dispersion are all investigated. Moreover, a compact on-chip all-optical wavelength converter is designed based on degenerate four-wave mixing in this waveguide. The dependencies of conversion efficiency and conversion bandwidth on the pump wavelength are discussed. The impact of pump power and signal power on the conversion efficiency is also investigated. The results show that a maximal conversion efficiency of −0.46 dB, and a 3-dB conversion bandwidth of 830 nm in the mid-infrared is achieved.

In this paper, a multichannel metal–insulator–metal (MIM) waveguide structure based on a disk resonator is proposed. The transmission characteristics of visible and near-infrared light in the waveguide are investigated by using the finite-difference time-domain (FDTD) method. The results show that the structure has typical band-pass filter function due to the wave resonance in the nanodisk. The energy of the second-order resonance wavelength of the disk can transmit through each output port averagely, which is realized by the energy separation function of the electromagnetic wave. Moreover, the wavelength will transmit through the output port in redshift as the radius and/or the refractive index of the disk are increased. The transmissivity is sharply reduced with the increase of the coupling thickness between the disk and the output port waveguide.

The theoretical problem of three-dimensional few cycle optical pulse (known as light bullet) propagation dynamics was considered in nonlinear medium containing carbon nanotubes. The stable and persistent propagation of optical pulses were found out.

In this work, spectra of energy and fluence of neutrons produced in the conditions of deformed space-time (DST), due to the violation of the local Lorentz invariance (LLI) in the nuclear interactions are shown for the first time. DST-neutrons are produced by a mechanical process in which AISI 304 steel bars undergo a sonication using ultrasounds with 20 kHz and 330 W. The energy spectrum of the DST-neutrons has been investigated both at low (less than 0.4 MeV) and at high (up to 4 MeV) energy. We could conclude that the DST-neutrons have different spectra for different energy intervals. It is therefore possible to hypothesize that the DST-neutrons production presents peculiar features not only with respect to the time (asynchrony) and space (asymmetry) but also in the neutron energy spectra.

An experimental study of oblique water entry of projectiles with different noses has been conducted using high-speed photography technology. The images of the initial water entry impact, cavity evolution, and the closure and shedding of vortices of cavity are presented in the paper. The results reveal that for high-speed oblique water entry (the initial impact velocity $>$50 m/s), the cavity attached to the projectile is symmetrical and free from the influence of gravity. The shedding of the water–vapor–air mixture in the tail of the cavity produces vortices which disappear in the rear of the projectile trajectory. Particular attention is given to the velocity attenuation of the projectile after water entry. The results show that there is a transition point at the time corresponding to the surface seal of the cavity during the velocity attenuation after oblique water entry, and the rates of velocity attenuation are different before and after this transition point. Additionally, the chronophotography of the cavity evolution shows that the time when the surface seal of the cavity occurs decreases with the increase of the initial impact velocity of the projectile.

The influences of a series of anion doping on the electronic structures of sodium niobate (NaNbO₃) have been systematically investigated by density functional theory (DFT) calculations with the hybrid B3LYP functional. As for B(C,P)-doped NaNbO₃, the isolated B 2p (C 2p, P 3p) states were formed above the valence band maximum (VBM) of NaNbO₃, which were too weak to mix with O 2p states and thus produced band gap narrowing. While the band gap of NaNbO₃ was slightly narrowed after F doping. As for S-doped NaNbO₃, the S 3p states mixed with O 2p states well and thus reduced the band gap energy. According to the calculation results, we tentatively put forward that S doping would be appropriate for single anion doping NaNbO₃, while the B(C,P) elements would be suitable candidates for co-doping NaNbO₃.