Simulation of the measurer of the time of appearance and the average power of the random pulse signal

The maximum likelihood measurer is considered of the time of appearance and the average power of the fast fluctuating Gaussian band pulse against Gaussian white noise. The possibilities of its practical implementation are demonstrated and its accuracy characteristics are determined. By statistical simulation methods, the experimental values of biases and variances of the resulting estimates are found. The error ranges of the theoretical formulas describing the measurer performance are established. There have been determined the conditions of high a posteriori accuracy for the measurer operation, that is, such signal-to-noise ratios above which the anomalous errors in estimating the pulse time parameter are practically non-existent

Surface ozone variability at Kislovodsk Observatory

The results of the surface ozone observations at the Observatory 'Kislovodsk', situated in the North Caucasus at the altitude 2070 m a.s.l., are given. The observatory is in the background conditions and the variations of the surface ozone are determined by the natural dynamic and photochemical processes. The mean value of the concentration and its seasonal variations are very near to those obtained at the high-mountain stations in Alps. The daily variations have the features, which remain stable during all warm period of the year (April-October). These features, including the minimum of the surface ozone at noon, are formed by the mountain-valley circulation. The significant variations of the surface ozone are connected with the unstationary lee waves

The path similarity method for phase measurements disambiguation

We introduce the technique for phase measurements disambiguation based on the paths similarity identification. To obtain these paths, we use phase and amplitude measurements. By simulation, the performance of the presented approach is established. Its application for the phase measurements disambiguation is demonstrated by the example of the phase correlative direction finder for which the amplitude correlative direction finding mode is activated without any hardware changes

Digital simulators of the random processes

The proposed universal digital simulators of random processes based on their Markov models are considered as capable of generating sequences of samples of unlimited duration. It is shown that a simple Markov chain allows generating the random numbers with a specified two-dimensional probability distribution of the neighboring values while a doubly connected Markov model makes it possible to get the three-dimensional random numbers. The parameters of the model are determined from either a known probability density or experimental samples of the simulated random process. It is demonstrated that the simulation algorithms do not require complex mathematical transformations and that they can be implemented using a simple element base. To change the properties of the generated random processes one needs to reload the memory device with a preformed data array. The block diagrams of the simulators are studied and the probabilistic and correlation characteristics of the generated random processes are determined. It is established that with these simulators a high accuracy of convergence of the probability distributions of the selected model and the histograms of the generated sample sequences is ensured. In the common studies, one can hardly find the results that can surpass by their efficiency the ones that the proposed simulation algorithms demonstrate accounting for their non-problematic hardware implementation (the minimum computational costs) and the simplicity of reconfiguring the Markov model based simulators for generating new random processes. The introduced simulators can be used in the design, development and testing of the multi-purpose electronic equipment, with different meters and the devices for simulating radio paths

Measurements of the total column amount of NO2 at Kislovodsk Observatory in 1979 - 1990

The results of the measurements of the NO2 total content at the 'Kislovodsk' observatory (North Caucasus 2070 m a.s.l.) in 1979-1990 are presented. The measurements were based on the absorption of the direct sunlight in the visible region of the spectrum. The variation of the NO2 content from the morning to the evening and the seasonal and year to year variations are analyzed. The less amplitude of the daily variations of the NO2 total content in comparison with the variations of the stratospheric NO2 content says about the significant insert of the tropospheric and lower stratospheric NO2 in its total content. The year to year variations of NO2 and ozone are in antiphase. Their values depends on the regional features of the atmospheric circulation. The quasibiennial oscillations of the total NO2 content are picked out

Radiative charge transfer lifetime of the excited state of (NaCa)+^+

New experiments were proposed recently to investigate the regime of cold atomic and molecular ion-atom collision processes in a special hybrid neutral-atom--ion trap under high vacuum conditions. The collisional cooling of laser pre-cooled Ca$^+$ ions by ultracold Na atoms is being studied. Modeling this process requires knowledge of the radiative lifetime of the excited singlet A$^1\Sigma^+$ state of the (NaCa)$^+$ molecular system. We calculate the rate coefficient for radiative charge transfer using a semiclassical approach. The dipole radial matrix elements between the ground and the excited states, and the potential curves were calculated using Complete Active Space Self-Consistent field and M\"oller-Plesset second order perturbation theory (CASSCF/MP2) with an extended Gaussian basis, 6-311+G(3df). The semiclassical charge transfer rate coefficient was averaged over a thermal Maxwellian distribution. In addition we also present elastic collision cross sections and the spin-exchange cross section. The rate coefficient for charge transfer was found to be $2.3\times 10^{-16}$ cm$^3$/sec, while those for the elastic and spin-exchange cross sections were found to be several orders of magnitude higher ($1.1\times 10^{-8}$ cm$^3$/sec and $2.3\times 10^{-9}$ cm$^3$/sec, respectively). This confirms our assumption that the milli-Kelvin regime of collisional cooling of calcium ions by sodium atoms is favorable with the respect to low loss of calcium ions due to the charge transfer.Comment: 4 pages, 5 figures; v.2 - conceptual change

Lignite from Central Watershed of the Yenisei River and Prospects for their use for Manufacture of Germanium

Лигниты среднего течения р. Енисей, локализованные в пределах мезокайнозойских отложений Касской впадины, рассматриваются как новый перспективный источник германиевого сырья в России. Приведены результаты изучения физико-химических свойств и технологических исследований, позволяющие оценить возможность выделения германия из лигнитов в процессе их сжигания для отработки, а в последующем для промышленной технологии его извлеченияLignite from central watershed of the Yenisei river localized within the Meso-Cenozoic cavity deposit considered as a promising new source of germanium raw materials in Russia. Germanium separating possibility from lignite during the combustion process has been studied on the base of physical and chemical properties research in order to develop the industrial technolog

A new application for x-ray lithography: Fabrication of blazed diffractive optical elements with a deep phase profile

Use of x-ray lithography to produce blazed diffractive optical elements (DOEs) is described. Proposed method allows one to make highly efficient blazed DOE with a deep phase profile (ten wavelengths and more) using a single x-ray mask with a binary transmission pattern. Unlike the well-known multilevel DOEs, blazed ones do not involve fabrication and aligning of a set of masks. DOEs with a profile depth of 10 {mu}m and more and zone sizes down to 1 {mu}m can be obtained due to the short wavelength and high penetrability of x rays. The first experimental samples of blazed DOEs with a 10 {mu}m-height profile--lenses and gratings - were fabricated by x-ray lithography with synchrotron radiation using the x-ray masks, prepared in accordance with the pulse-width modulation algorithm. Diffraction efficiency for lenses was measured for white light: it is higher than 80% for the central part of the lenses (inside a 10 mm diameter) and about 60% for an area of 20 mm diameter

Synthesis and properties of the heterospin (S1 = S2 = 1/2) radical-ion salt bis(mesitylene)molybdenum(I) [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazolidyl

The authors are grateful to the Presidium of the Russian Academy of Sciences (Project 8.14), the Royal Society (RS International Joint Project 2010/R3), the Leverhulme Trust (Project IN-2012-094), the Siberian Branch of the Russian Academy of Sciences (Project 13), the Ministry of Education and Science of the Russian Federation (Project of Joint Laboratories of Siberian Branch of the Russian Academy of Sciences and National Research Universities), and the Russian Foundation for Basic Research (Projects 13-03-00072 and 15-03-03242) for financial support of various parts of this work. N.A.S. thanks the Council for Grants of the President of Russian Federation for postdoctoral scholarship (grant MK-4411.2015.3). B.E.B. is grateful for an EaStCHEM Hirst Academic Fellowship. A.V.Z. thanks the Foundation named after D. I. Mendeleev, Tomsk State University, for support of his work.Low-temperature interaction of [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (1) with MoMes2 (Mes = mesitylene / 1,3,5-trimethylbenzene) in tetrahydrofuran gave the heterospin (S1 = S2 = 1/2) radical-ion salt [MoMes2]+[1]– (2) whose structure was confirmed by single-crystal X-ray diffraction (XRD). The structure revealed alternating layers of the cations and anions with the Mes ligands perpendicular, and the anions tilted by 45°, to the layer plane. At 300 K the effective magnetic moment of 2 is equal to 2.40 μB (theoretically expected 2.45 μB) and monotonically decreases with lowering of the temperature. In the temperature range 2−300 K, the molar magnetic susceptibility of 2 is well-described by the Curie-Weiss law with parameters C and θ equal to 0.78 cm3⋅K⋅mol–1 and −31.2 K, respectively. Overall, the magnetic behavior of 2 is similar to that of [CrTol2]+[1]– and [CrCp*2]+[1]–, i.e. changing the cation [MAr2]+ 3d atom M = Cr (Z = 24) with weak spin-orbit coupling (SOC) to a 4d atom M = Mo (Z = 42) with stronger SOC does not affect macroscopic magnetic properties of the salts. For the XRD structure of salt 2, parameters of the Heisenberg spin-Hamiltonian were calculated using the broken-symmetry DFT and CASSCF approaches, and the complex 3D magnetic structure with both the ferromagnetic (FM) and antiferromagnetic (AF) exchange interactions was revealed with the latter as dominating. Salt 2 is thermally unstable and slowly loses the Mes ligands upon storage at ambient temperature. Under the same reaction conditions, interaction of 1 with MoTol2 (Tol = toluene) proceeded with partial loss of the Tol ligands to afford diamagnetic product.PostprintPostprintPeer reviewe