The process of spin polarization transfer in the NV– — P1 system in diamond in the vicinity of LAC is studied. A method based on a complete set of commuting observables was used. It was shown that with optical pumping of the NV– — P1 system in a field of B ≈ 511.5 G at room temperature, polarization can be transferred efficiently from the electron spin of the NV center to the electron spin of the P1-center.
We study the properties of the spin states in single diamond 15NV–-center at the ground state level anti-crossing. Our approach uses a complete set of commuting operators. We have shown that under certain conditions in 15NV–-center it is possible to obtain a 100 % transfer of polarization from the electron spin to the spin of the 15N nucleus. We believe that these conditions can be satisfied for 15NV–-centers obtained by implantation.
The requirements for medium-and long-wave antenna systems imply further improvement of their electrodynamic and structural properties, which is primarily related to the specifics of using this range to provide communication with mobile objects, including surface ships, radio broadcasting, transmit special-purpose signals and other purposes. At the same time, considerable attention is paid to the structures of transmitting antennas, the possibility of reducing their size, reducing mutual influence in a complex electromagnetic environment, and improving the reliability of radio communications. The presented work is devoted to the development of this direction from the point of view of radio engineering.
The features of modeling gas flows with evaporating droplets are considered. Such flows are found in power plants and technological devices. The resistance curve for a drop with corrections for quasi-stationary motion, the dependence of the correction coefficient on the dimensionless intensity of evaporation, the dependence of the dimensionless intensity of the pulsation energy decrease on various parameters are studied. Graphs are represented in dimensionless variables. It was found that increasing the size of the droplets will cause a change in their shape and coefficient of hydrodynamic resistance.
An approximate solution of the problem of the structure and characteristics of a stationary nonlinear periodic wave on the surface of a liquid of finite depth has been obtained. The solution is as follows: first, the kinematic and dynamic conditions are simplified. The Bernoulli integral contributes to the simplification of the dynamic condition. An integral operator of convolution type is introduced. Four functions of one variable are determined, the main of which is the wave level. One linear and three quadratic equations are obtained. The zero mean conditions for the level and the relative function of the current, as well as the condition of orthogonally of the wave level and the fundamental harmonic, are determined and validated. Like Stokes did, we seek unknown functions and parameters as expansions in a dimensionless wave number. The nonlinear dispersion relation has been obtained. The decision analysis has been completed. The cases of short and long waves have been considered.
This work is related to the field of radio engineering and is devoted to the search for ways to improve the transmission antennas of the SDV- and DV- bands based on the study of electrodynamic properties with the possibility of improving their design, mass-dimensional and radiating parameters. These ranges are widely used for communication with mobile objects in areas with high magnetic activity, as well as in Maritime Strait zones; for direction finding of radiation when determining the location of an aircraft or vessel. The results of the work can find practical application in solving problems of improving the safety of sea and air traffic.
A spatially non-local fourth-order wave equation with a source is considered. The results are set out in terms of the heat transfer theory. The temperature derivative of the source function is positive (a technical source) or negative (a source in biological tissue). The wave velocity (subsonic, sonic, supersonic) is determined with respect to the velocity of propagating heat perturbations. We give examples of the exact solving the problem of disintegration of a weak discontinuity in the temperature field. This problem is set as follows. In the initial state the continuous thermal field contains a point of a weak discontinuity; in that point the first coordinate derivative undergoes a first-order rupture. Further the weak discontinuity disintegrates into two waves which propagate in opposite directions. Initiation of such waves is discussed in detail. A technical source: two subsonic, sonic or supersonic waves; the non-uniform space in front of the waves is spatially periodic; in a particular case spatial non-uniformity is localized on both sides of a weak discontinuity. A source in biological tissue: the thermal field between the waves is a superposition of two running waves for which the product of velocity moduli is equal to the square of propagating thermal perturbations velocity. The non-uniform space in front of the waves is spatially periodic and is displayed as spatial coordinate beating. An example is built for disintegration of a weak discontinuity when time evolution in the perturbed region leads to forming a standing wave.
We note that it is no accident that modern science cannot answer to the question why our space we exist in and which we see is three-dimensional. Therefore, it is believed that attempts to find an answer to this question, by remaining only within the mathematics, are bound to fail. On the contrary, it is in the present math study that it is shown that why space is three-dimensional can only be explained only by means of higher arithmetic. This is followed by an answer to the following important question. Where and how the loss and subsequent recovery of symmetry in spatial numerical figures occurs. Why is there a loss of stable numerical symmetry? The present arithmetic study will show that behind the external randomness of the real numbers around us is an infinite degree of their organizations, which is based on numerical matrix called the «Pascal's triangle» being placed in space. Because any segment of any increasing real number series belongs to any sequence in which each term is defined as some function of the previous ones.