This article deals with the issues of modeling the trajectory of an object moving on a plane. Its trajectory may intersect with obstacles (circles). The author proposes an algorithm for modifying the ...initial trajectory of the object taking into account the movement of obstacles. At the beginning, we describe how to divide the initial trajectory into sections. Then we describe how to modify the line on each segment in two cases, depending on the angle between the projection direction and the direction of movement of the obstacle center.
Here, we report the results of our 1H nuclear magnetic resonance study of the dynamics of water molecules confined in zeolites (mordenite and ZSM-5 structures) with hierarchical porosity (micropores ...in zeolite lamella and mesopores formed by amorphous SiO2 in the inter-lamellar space). 1H nuclear magnetic resonance (NMR) spectra show that water experiences complex behavior within the temperature range from 173 to 298 K. The temperature dependence of 1H spin-lattice relaxation evidences the presence of three processes with different activation energies: freezing (about 30 kJ/mol), fast rotation (about 10 kJ/mol), and translational motion of water molecules (23.6 and 26.0 kJ/mol for pillared mordenite and ZSM-5, respectively). For translational motion, the activation energy is markedly lower than for water in mesoporous silica or zeolites with similar mesopore size but with disordered secondary porosity. This indicates that the process of water diffusion in zeolites with hierarchical porosity is governed not only by the presence of mesopores, but also by the mutual arrangement of meso- and micropores. The translational motion of water molecules is determined mainly by zeolite micropores.
The photocatalytic activity of layered perovskite-like oxides in water splitting reaction is dependent on the hydration level and species located in the interlayer slab: simple or complex cations as ...well as hydrogen-bonded or non-hydrogen-bonded H2O. To study proton localization and dynamics in the HCa2Nb3O10·yH2O photocatalyst with different hydration levels (hydrated—α-form, dehydrated—γ-form, and intermediate—β-form), complementary Nuclear Magnetic Resonance (NMR) techniques were applied. 1H Magic Angle Spinning NMR evidences the presence of different proton containing species in the interlayer slab depending on the hydration level. For α-form, HCa2Nb3O10·1.6H2O, 1H MAS NMR spectra reveal H3O+. Its molecular motion parameters were determined from 1H spin-lattice relaxation time in the rotating frame (T1ρ) using the Kohlrausch-Williams-Watts (KWW) correlation function with stretching exponent β = 0.28: Ea=0.2102 eV, τ0=9.01 × 10−12 s. For the β-form, HCa2Nb3O10·0.8H2O, the only 1H NMR line is the result of an exchange between lattice and non-hydrogen-bonded water protons. T1ρ(1/T) indicates the presence of two characteristic points (224 and 176 K), at which proton dynamics change. The γ-form, HCa2Nb3O10·0.1H2O, contains bulk water and interlayer H+ in regular sites. 1H NMR spectra suggest two inequivalent cation positions. The parameters of the proton motion, found within the KWW model, are as follows: Ea=0.2178 eV, τ0=8.29 × 10−10 s.
The collection of the Ural, Anabar and Brazilian diamonds conducted research by infrared spectrometry method. It was found that a diamond with a low degree of aggregation of nitrogen defects ...composing the crystals of the later generation from mantle eclogite xenoliths and outer zones of the greater part of the crystals from deposits of kimberlite-lamproite type is missing or is poorly developed in the crystals of the Ural type. Conclusions about the thermal conditions of the Ural diamonds formation and their possible affinity to the specification and type of original sources.
Here, we report the results of our sup.1H nuclear magnetic resonance study of the dynamics of water molecules confined in zeolites (mordenite and ZSM-5 structures) with hierarchical porosity ...(micropores in zeolite lamella and mesopores formed by amorphous SiOsub.2 in the inter-lamellar space). sup.1H nuclear magnetic resonance (NMR) spectra show that water experiences complex behavior within the temperature range from 173 to 298 K. The temperature dependence of sup.1H spin-lattice relaxation evidences the presence of three processes with different activation energies: freezing (about 30 kJ/mol), fast rotation (about 10 kJ/mol), and translational motion of water molecules (23.6 and 26.0 kJ/mol for pillared mordenite and ZSM-5, respectively). For translational motion, the activation energy is markedly lower than for water in mesoporous silica or zeolites with similar mesopore size but with disordered secondary porosity. This indicates that the process of water diffusion in zeolites with hierarchical porosity is governed not only by the presence of mesopores, but also by the mutual arrangement of meso- and micropores. The translational motion of water molecules is determined mainly by zeolite micropores.
The double-differential production cross-section of positive pions, , measured in the HARP experiment is presented. The incident particles are 8.9 GeV/c protons directed onto a beryllium target with ...a thickness of 5% of a nuclear interaction length. The measured cross-section has a direct impact on the prediction of neutrino fluxes for the MiniBooNE and SciBooNE experiments at Fermilab. After cuts, 13 million protons on target produced about 96000 reconstructed secondary tracks which were used in this analysis. Cross-section results are presented in the kinematic range 0.75 GeV/c≤pπ≤ 6.5 GeV/c and 30 mrad≤θπ≤ 210 mrad in the laboratory frame.
Most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, EUSO, TUS, etc.) use air fluorescence to detect and measure extensive air showers (EAS). The precise ...knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the reconstruction of UHECR. The MACFLY—Measurement of Air Cherenkov and Fluorescence Light Yield—experiment has been designed to perform such FLY measurements. In this paper we will present the results of FLY in the 290–440
nm wavelength range for dry air and pure nitrogen, both excited by electrons with energy of 1.5
MeV, 20
GeV and 50
GeV. The experiment uses a
90Sr radioactive source for low energy measurement and a CERN SPS e
− beam for high energy. We find that the FLY is proportional to the deposited energy (
E
d) in the gas and we show that the air fluorescence properties remain constant independently of the electron energy. At the reference point: atmospheric dry air at 1013
hPa and 23
°C, the ratio FLY/
E
d
=
17.6 photon/MeV with a systematic error of 13.2%.
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