Motion-induced energy shifts of a multilevel atom in a black-body radiation field

We investigate the influence of atomic uniform motion on radiative energy shifts of a multilevel atom when it interacts with black-body radiation. Our analysis reveals that the atomic energy shifts depend crucially on three factors: the temperature of black-body thermal radiation, atomic velocity, and atomic polarizability. In the low-temperature limit, the presence of atomic uniform motion always enhances the effect of the thermal field on the atomic energy shifts. However, in the high-temperature limit, the atomic uniform motion enhances the effect of the thermal field for an atom polarizable perpendicular to the atomic velocity but weakens it for an atom polarizable parallel to the atomic velocity. Our work indicates that the physical properties of atom–field coupling systems can in principle be regulated and controlled by the combined action of the thermal field and the atomic uniform motion.

Passive Measurements of the Refractive Index of Liquid Nitrogen and Free-flowing substances by the Prism Method in the Millimeter Wavelength Range

It is proposed to use the classical prism method in the millimeter wavelength range for measuring the refractive index of liquid and free-flowing substances, including mixtures with particle sizes comparable to the wavelength. The method is implemented using a hollow radio transparent rectangular prism filled with a test substance. The measurements were carried out in the thermal radiation mode using radiometers with horn-lens antennas at frequencies of 37.5 and 94 GHz. To measure the deflection of the refracted beam, a linear scanner with a black body mounted on it, cooled with liquid nitrogen, was used. The distance between the prism and the scanner was 1 m. The refractive index of liquid nitrogen, sand, gravel, marble chips and granular polyethylene were measured. Using the refractive formula and the Landau-Lifshitz-Looeng formula for calculating the dependence of the refractive index of binary mixtures on the bulk density of particles, estimates of the refractive index of the material of the particles that make up the substances under study are obtained. They are in satisfactory agreement with the known experimental data for quartz, feldspar, granite, and marble.

RELATIVISTIC CALCULATION OF THE RADIATIVE TRANSITION PROBABILITIES AND LIFETIMES OF EXCITED STATES FOR THE RUBIDIUM ATOM IN A BLACK-BODY RADIATION FIELD

We present the results of relativistic calculation of the radiative transition probabilities and excited states lifetimes for a heavy Rydberg atomic systems in a black-body (thermal) radiation field on example of the rubidium. As theoretical approach we apply the combined generalized relativistic energy approach and relativistic many-body perturbation theory with ab initio Dirac zeroth approximation. There are obtained the calculational data for the radiative transition probabilities and excited states lifetimes, in particular, the rubidium atom in the Rydberg states with principal quantum number n=10-100. It is carried out the comparison of obtained theoretical data on the effective lifetime for the group of Rydberg nS states of the rubidium atom at a temperature of T = 300K with experimental data as well as data of alternative theoretical calculation based on the improved quasiclassical model. It is shown that the accuracy of the theoretical data on the radiative transition probabilities and excited states lifetimes is provided by a correctness of the corresponding relativistic wave functions and accounting for the exchange-correlation effects.

Enhanced Photothermal and Photoacoustic Performance of Graphene Oxide in NIR-II Biowindow by Chemical Reduction

We report on a novel strategy for constructing graphene oxide nanomaterials with strongly enhanced photothermal (PT) and photoacoustic (PA) performance in the near-infrared (NIR)-II biowindow by chemical reduction. Optical spectra clearly reveal that obvious enhancement of optical absorption is observed in the whole NIR wideband from the NIR-I to NIR-II region for chemically reduced graphene oxide (CR-G) nanomaterials, which is mainly arising from the restoration of the electronic conjugation within the graphene oxide sheets and therefore inducing a black-body re-introduction effect of typical graphite-like materials. We experimentally synthesized CR-G samples with different degrees of reduction to demonstrate the efficiency of the proposed strategy. Experimental results show that the PT performance of the CR-G samples is greatly improved owing to the absorption enhancement by chemical reduction in the NIR-II biowindow. Furthermore, both in vitro and in vivo PA imaging of the CR-G samples with different degrees of reduction are performed to demonstrate their enhanced NIR-II PA performances. This work provides a feasible guidance for the rational design of graphene oxide nanomaterials with great potential for PT and PA applications in the NIR-II biowindow by chemical reduction.

Geometric Mediator Structures, Transition Dynamics and Force Constants

It is shown in the present work that the distorted-space model of matter can describe conventional force-constants and transition-mediator structures. We use the verbiage “distorted” to communicate the concept of “energetic warping” to distinguish “spatial warping” from “classical matter warping”, although the concept of “matter” is in fact, in the present context, the “geometric distortion energy” of the spatial manifold itself without a classical “matter stressenergy source”. The “distorted-geometry” structures exhibit non-Newtonian features wherein the hole or core-region fields of the structures are energetically-repulsive (negative pressure), do not behave functionally in an r -4 manner and terminate at zero at the radial origin (no singularity). Near the core of the distortion the magnetic fields dominate the energy-densities of the structures thereby departing from classical particle-structure descriptions. Black-body radiation-emission and structural modeling lead to a description of transition dynamics and photonic entities.

Geometric Mediator Structures, Transition Dynamics and Force Constants

It is shown in the present work that the distorted-space model of matter can describe conventional force-constants and transition-mediator structures. We use the verbiage “distorted” to communicate the concept of “energetic warping” to distinguish “spatial warping” from “classical matter warping”, although the concept of “matter” is in fact, in the present context, the “geometric distortion energy” of the spatial manifold itself without a classical “matter stressenergy source”. The “distorted-geometry” structures exhibit non-Newtonian features wherein the hole or core-region fields of the structures are energetically-repulsive (negative pressure), do not behave functionally in an r -4 manner and terminate at zero at the radial origin (no singularity). Near the core of the distortion the magnetic fields dominate the energy-densities of the structures thereby departing from classical particle-structure descriptions. Black-body radiation-emission and structural modeling lead to a description of transition dynamics and photonic entities.

Morphological and morphometric studies on the scapula and humerus of Binturong (Arctictis Binturong)

Natural Habitat of Binturong is the forest remnant of South-east Asia. Common characteristic features of a Binturong are its shout legs, thick black body coat and prehensile tail. After collecting the samples from Aizawl Zoological Park, Mizoram with permission from the Department of Environment, Forest and Climate change, Government of Mizoram, those were macerated by the combination of boiling hot water and HODifferent morphometric parameters of scapula and humerus were measured. Scapula of Binturong was a flat almost square shaped bone with similar width in both dorsal and ventral border with a wide scapular neck, average circumference of which is around 8.04 cm. Average maximum length and width of the scapula of Binturong was 8.81 cm and 6.56 cm, respectively. A small foramen was seen at the neck of the scapula perforating the ventral portion of the scapular spine. Average maximum total length of Binturong Humerus was 12.81 cm. Proximal extremity of the humerus carries a caudally present oval shaped head, average maximum width of which is about 2.05cm. Distal extremity of the Binturong humerus is consists of a supracondylar foramen, a radial fossa, a olecranon fossa, lateral and medial condyle and epicondyle. Since not much work has been done on the related field in this particular animal, therefore this present study was conducted to get the baseline data about the two bones of forelimb in Binturong, which can play a predominant role in disease diagnosis, treatments and other applied fields of veterinary biology.

Effect of Diamond Polishing and Thermal Treatment on Carbon Paramagnetic Centers’ Nature and Structure

Diamonds contain carbon paramagnetic centers (stable carbon radicals) in small concentrations (at the level of ~1 × 1012 spins/mg) that can help in elucidating the structure of the nitrogen atoms’ contaminants in the diamond crystal. All diamonds that undergo polishing are exposed to high temperatures, owing to the friction force during the polishing process, which may affect the carbon-centered radicals’ concentration and structure. The temperature is increased appreciably; consequently, the black body radiation in the visible range turns orange. During polishing, diamonds emit an orange light (at a wavelength of about 600 nm) that is typical of a black body temperature of 900 °C or higher. Other processes in which color-enhanced diamonds are exposed to high temperatures are thermal treatments or the high-pressure, high-temperature (HPHT) process in which the brown color (resulting from plastic deformation) is bleached. The aim of the study was to examine how thermal treatment and polishing influence the paramagnetic centers in the diamond. For this purpose, four rough diamonds were studied: two underwent a polishing process, and the other two were thermally treated at 650 °C and 1000 °C. The diamonds were analyzed pre- and post-treatment by EPR (Electron Paramagnetic resonance), FTIR (Fourier transform infrared, fluorescence, and their visual appearance. The results indicate that the polishing process results in much more than just thermal heating the paramagnetic centers.

Geometric Mediator Structures, Transition Dynamics and Force Constants

It is shown in the present work that the distorted-space model of matter can describe conventional force-constants and transition-mediator structures. We use the verbiage “distorted” to communicate the concept of “energetic warping” to distinguish “spatial warping” from “classical matter warping”, although the concept of “matter” is in fact, in the present context, the “geometric distortion energy” of the spatial manifold itself without a classical “matter stressenergy source”. The “distorted-geometry” structures exhibit non-Newtonian features wherein the hole or core-region fields of the structures are energetically-repulsive (negative pressure), do not behave functionally in an r -4 manner and terminate at zero at the radial origin (no singularity). Near the core of the distortion the magnetic fields dominate the energy-densities of the structures thereby departing from classical particle-structure descriptions. Black-body radiation-emission and structural modeling lead to a description of transition dynamics and photonic entities.