The results of research on a new type of microscopy—ghost imaging microscopy, which has the advantages of ghost imaging—are presented. A consistent theory of ghost imaging microscopy with an incoherent light source has been developed. The optical scheme of the ghost imaging microscope includes two objective lenses in the object channel and one lens in the reference channel. The calculation of the mutual spatial correlation function of channel intensities containing information about the object under study is presented. It is shown that visualization using ghost imaging microscopy is possible when the lens condition in the object channel is not met, which distinguishes this type of microvisualization from optical one. A source of pseudo-thermal radiation was used in experimental studies. Ghost images of biological preparations of ascomycete fungi of Aspergillus genus and animal epidermal cells have been reconstructed. The resulting images demonstrate the transmission of the main structural elements of the objects under study.
A generalization of the Fäldt–Wilkin formalism, which relates the meson production cross sections with the emission of a deuteron to those with the emission of a nucleon pair in the final state, is proposed for higher excitation energies of the final pair of nucleons. To derive the relationship between the cross sections, a model of interaction with an additional non-nucleon channel is used, in which the relationship between the corresponding amplitudes is determined by the energy dependence of the non-nucleon component of the NN -system wavefunction. It is shown that the obtained cross section ratio is practically independent of the interaction model at excitation energies of the nucleon pair from 0 to 40–50 MeV. As an example, the ratios of total and differential cross sections of the reaction pp → pnπ^ + to the corresponding cross sections of pp → dπ^ + are considered. It is shown that the proposed generalized formalism for taking into account the final-state interaction of nucleons describes well the experimental data at energies of incident protons below 600 MeV.
In the temperature range T = 30- 300 K, the process of magnetization reversal of ultrathin Co layers, isolated and exchange-coupled through a Pd layer, was experimentally studied, and the nucleation fields H_N were determined. It was found that a crossover is observed in the H_N(T) dependences of exchange-coupled films. In the high temperature region, where the layers undergo magnetization reversal independently of each other, as in single-layer films, H_N∼T^ - 1 , in the low temperature region, where the layers undergo a correlated magnetization reversal, H_N∼ln (T^ - 1) . The performed numerical calculations showed interlayer exchange interaction is the key factor driving nucleation in the heterostructure, qualitatively explaining the observed dependence H_N(T) .
In this work, for the first time, a comprehensive experimental and theoretical study was carried out on the influence of copper substitution with magnetically active metals TM = Mn, Fe, Co, Ni on the thermoelectric and magnetic properties of tetrahedrites of the composition Cu11TM1Sb4S13. Maximum value of thermoelectric figure of merit zT_max = 1.34 at 735 K was achieved for the unalloyed sample. It was established that doping 3d -metals leads to a decrease zT due to a decrease in electrical conductivity and an increase in thermal conductivity. Experimental data show that with decreasing charge number 3d -ion, an increase in the magnetic moment at the substitution position is observed. However, for the entire series of compositions, no significant increase in magneto-thermoEMF was detected. The calculations carried out within the framework of the density functional theory qualitatively reproduce the experimental data and confirm that the contribution of spin entropy, magnon drag and other spin-caloritron mechanisms to the thermoelectric properties in tetrahedrites with substitutions 3d-metals is insignificant.
The measurement results A -dependences of the relative yields of neutral mesons π^0 , ω (782) , f_2(1270) and K_S^0 in relation to η -meson produced in π^ + A -interactions at a momentum of 7 GeV/c are presented. The measurements were performed on six nuclear targets (Be, C, Al, Cu, Sn, Pb) in the Hyperon-M experiment at the U-70 accelerator complex. Mesons were identified by their photon decays using the LGD2 wide-aperture electromagnetic calorimeter. The yield ratios of the mesons under study to the yield η -mesons were measured in the beam fragmentation region ( x_F > 0.6 in the center of mass system π N -reactions). It is shown that the relative yields of non-strange mesons ( π^0 , ω (782) , f_2(1270) ) decrease with increasing the mass number of the target nucleus. At the same time, the yield ratio K_S^0/η demonstrates a steady statistically significant increase with increasing A . The obtained results are important for the study of hadron–nucleus interactions at intermediate energies, including testing and fine-tuning transport models such as GiBUU, PHSD, UrQMD, SMASH, regarding the influence of collective effects in the nucleus on the production of mesons with different quark compositions.
