物理与天体物理最新文献

In recent years, the demand for optical imaging and detection in hypersonic aircraft has been on the rise. The high-temperature and high-pressure compressed flow field near airborne optoelectronic devices creates significant interference with light transmission, known as hypersonic aero-optical effects. This effect has emerged as a key technological challenge, limiting hypersonic optical imaging and detection capabilities. This article focuses on introducing the thermal effects and optical transmission effects of hypersonic aero-optical effects, as along with corresponding suppression techniques. In addition, this article critically reviews and succinctly summarizes the advancements made in hypersonic aero-optical effects testing technology, while also delineating avenues for future research needs in this field. In conclusion, there is an urgent call for further exploration into the study of aero-optical effects under conditions characterized by high Mach, high enthalpy, and high Reynolds number in the future.

The interaction of biologically active molecules (BAM) with the biopolymer DNA, which performs the most important functions in a living organism having a double helical structure, irradiated with non-thermal electromagnetic millimeter waves, has been studied. It has been shown, that BAM (doxorubicin, mitoxantrone, and netropsin) form more stable complexes with DNA irradiated with the resonant frequencies of natural vibrations of the molecular structures of water (64.5 and 50.3 GHz). Under the influence of the above non-thermal millimeter waves, dehydration of the DNA molecule occurs, which leads to an increase in the binding constant of BAM to irradiated DNA. Calculations show that as a result of irradiation, the thermodynamic parameters of the binding of BAM to DNA change-enthalpy (ΔH) and entropy (ΔS): For all studied BAM, ΔH < 0, and ΔS > 0. The greatest change in entropy occurs for netropsin that binds externally to DNA.

The thermodynamic characteristics of an electron gas localized in a thin spherical CdSe nanolayer have been studied. The dimensions of the CdTe/CdSe core-shell type quantum dot are considered large, which allows the gas to be considered ideal. Due to the small thickness, the particle spectrum has a subband character, when a family of levels of the spherical rotator is associated with each radial quantization level. Within the framework of Boltzmann statistics, the statistical sum for the gas under study was determined, as well as the mean energy, entropy, and heat capacity. The dependences of the thermodynamic characteristics of the electron gas on the geometric parameters of a CdTe/CdSe quantum dot have been studied.

The present work investigates influence of self-focused elliptical laser beam on second harmonic generation (SHG) in cold quantum plasma (CQP). There is establishment of transverse intensity gradients on account of self-focused elliptical laser beam in relativistic plasma. These intensity gradients cause excitation of electron plasma wave (EPW) at pump beam’s frequency. Excited EPW interacts nonlinearly with pump wave thereby producing 2nd harmonics. The nonlinear differential equations representing beam waist’s behavior against normalized distance is derived through Wentzel, Kramers and Brillouin (WKB), approach and paraxial theory. Nonlinear Ordinary differential equation (ODE) is solved numerically in order to explore effect of distinct laser-plasma parameters and quantum contribution on beam waist of pump wave and 2nd harmonics efficiency. The present outcome is compared with classical relativistic plasma (CRP) case.

Macroscopic and structural properties of one-dimensional (1D) dipolar fluids are investigated theoretically. The equation of state is fully explored by means of analytical limiting laws, integral equations and corroborating Monte Carlo simulations. An interesting mapping with the Tonks gas (i.e., hard rods) is established at strong coupling. Crucially, we report a novel solid phase characterized by a textit{universal algebraic decay} of the pair distribution function whose range extends with increasing coupling. This discovery provides a clarified view in 1D systems and open new routes to explore theoretically as well as experimentally.