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Abstract—The results of experimental studies on the propagation of low-frequency pulsed signals in deep- and shallow-water areas of the World Ocean are presented. Sufficient conditions have been obtained for separation rays based on their arrival time at the reception point: displacement of the ray under the influence of the downward sound velocity gradient directed exceeds displacement of the ray in the opposite direction under the influence of the gradient due to gravity; the emitter and receiver are at different depths; the emission is pulsed for a pulse duration smaller than the difference in the ray arrival times at the reception point. The experiments validated the hypothesis that the aggregate conditions are sufficient to detect rays by their arrival time. [ABSTRACT FROM AUTHOR]

Curves of equal loudness for sounds of different frequencies and auditory frequency responses are discussed. It is shown that curves of equal loudness do not describe the auditory frequency response and are applicable only to tonal signals. The auditory frequency response can adapt to the sound spectrum. For music, a broadband frequency response is formed; for speech, a frequency response with low-frequency suppression is used. [ABSTRACT FROM AUTHOR]

A comparative analysis was performed of the impact on living organisms, in terms of genotoxicity, of two factors, namely, radiation (residual 137Cs) and a chemical factor (pesticides). The experiment was conducted both on individual pesticide samples and the aqueous extracts of soil samples. Soil samples were collected in the territory of the Orel region (Russia) from May 12 to May 15, 2010, i.e., years after the Chernobyl accident. Changes in the mutagenic index derived from Ames assay (Salmonella/microsomes) and the data obtained from mammalian cell culture in the Cricetulus griseus test (Chinese hamster) of the soil samples arising from the cesium radioactivity and the content of pesticides in these samples were considered. No direct correlation was found between dose level and genotoxicity at low radiation doses (20 μR/h), i.e., correlation with DNA mutations produced, both in terms of frameshifting and the base replacement type. On the contrary, a clear tendency was observed for increase in genotoxicity with increase in the concentration of pesticides and the entire amount of anthropogenic toxicants in the studied soil samples. [ABSTRACT FROM AUTHOR]

The long-term changes in annual maximum flow for the unregulated rivers of the Russian Federation are analyzed using data from 513 Roshydromet gaging stations. The following are evaluated: linear trends in the series of maximum river flow for the period of 1950–2016 and its statistical characteristics (mean values, variance, the number of years with the exceeding of the 10% probability maximum runoff) for two multiyear periods (the modern climate warming and the previous one). As a result, the zoning of the Russian territory is made according to the direction and intensity of modern changes in these parameters. The probability of historical maxima registered for the rivers at the beginning of the 21st century is estimated. [ABSTRACT FROM AUTHOR]

Monodisperse spherical nanoporous silicon (np-Si) particles of submicrometer size are fabricated with mesoporous silica particles as a template. Silicon is synthesized within the mesopores of monodisperse silica particles by the thermal decomposition of monosilane. Then, the template material (a-SiO2) is removed by wet etching. The particles obtained have a small root-mean-square size scatter (no more than 10%) and large specific surface area (250 m2 g–1) and pore volume (0.5 cm3 g–1). It is shown that np-Si particles exhibit photoluminescence in the visible and near-IR (infrared) spectral ranges. [ABSTRACT FROM AUTHOR]

The trend fractionation of the 238U and 235U isotopes and the extent of this process at the oxidative weathering of uranium minerals were evaluated by studying the variations in the U isotope composition of rocks, minerals, and fracture waters sampled in the quarry of the broadly known Tulukuevskoe uranium deposit in the Streltsovskoe ore field, eastern Transbaikalia. In the rock block in question, fine uranium minerals disseminated in the rocks were weathered under the effect of oxidizing fracture waters. Uranium isotope composition was measured in 22 water samples, eleven samples of the mineralized rocks, and eight uranium minerals. High-precision (±0.07‰, 2SD) measurements of the 238U/235U were carried out by MC-ICP-MS, using a 233U–236U double spike. The results involve the 238U/235U and 234U/238U ratios and the overall range of the δ238U variations determined in the rocks and waters (from –0.13 to –1.0‰ and from –0.22 to –0.59‰, respectively). Interaction between the waters and rocks induces U(IV) → U(VI) oxidation, U(VI) transfer into the aqueous phase, and 0.15–0.28‰ enrichment of U dissolved in the water in the 235U isotope. When the pitchblende is replaced by U(VI) minerals, the 238U and 235U isotopes also fractionate with ~0.3‰ enrichment of the younger U(VI) mineral phases in the light 235U isotope. The 238U/235U and 234U/238U ratios are proved to correlate, and hence, the fractionation of the 238U and 235U isotopes and the enrichment of the aqueous phase in the light 235U isotope proceed simultaneously with the well known shift in equilibrium the 238U–234U system with the accumulation of excess amounts of the 234U in the aqueous phase. Uranium leaching from uranium minerals, which is associated with the enrichment of the aqueous phase in excess amounts of the 234U isotope, can be viewed as a process that controls isotope fractionation in the 238U–235U system. This should be taken into account in describing the fractionation mechanism of the 238U and 235U isotopes at U(IV) → U(VI) oxidation. The fractionation of the 238U and 235U isotopes, which results in the isotopic "lightening" of U in the aqueous phase, largely controlled the complicated distribution pattern of the 238U/235U ratio in the quarry. In addition to isotope fractionation, this distribution was likely also affected by isotope exchange between uranium dissolved in the water and uranium in the finely dispersed minerals. The isotopically light uranium of the water could participate in forming U(VI) minerals at lower levels of the quarry. [ABSTRACT FROM AUTHOR]

Luminescence spectra of single crystals of rare-earth gallium borates LnGa3(BO3)4 (Ln = Nd, Sm, Tb, Er, Dy, or Ho) at room (300 K) and cryogenic (10 K) temperatures are presented for the first time. Photoluminescence has been recorded in the wavelength range of 470–5000 nm (2000–21 300 cm–1) with a high spectral resolution (down to 0.1 cm–1) upon excitation by different diode lasers. The spectra obtained cannot be unambiguously interpreted within one luminescent center, which can be due to the presence of defects and/or inclusions of other crystalline phases. The optical nonlinearity of rare-earth–gallium borates has been estimated using the Kurtz–Perry powder technique. The typical intensities of the second-harmonic generation in gallium borate powders are 30–40 (with respect to quartz), and the optical nonlinearity is as good as the nonlinearity of the efficient rare-earth aluminum borate YAl3(BO3)4. [ABSTRACT FROM AUTHOR]

The Transbaikal sector of the Mongol–Okhotsk orogenic belt displays a well-consistent geochemical and metallogenic zoning. The axial zone of the belt, which is controlled by the Mongol–Okhotsk suture zone from the north, is composed of reduced ilmenite-series rocks. Tin, tungsten, and rare-metal deposits and occurrences previously distinguished by S.S. Smirnov as a rare-metal belt are confined to the ilmenite-series rocks. The reduced rocks are framed from the north and south by oxidized magnetite-series rocks with chalcophile mineralization. The distribution zones of the ilmenite-series rocks correspond to anomalies with lower gravity and magnetic fields, whereas the magnetite-series oxidized rocks correspond to anomalies with higher gravity and magnetic fields. [ABSTRACT FROM AUTHOR]

Designing two-step tuning based on substitution of multiple cation lattices and energy transfer successfully achieved versatile colour output for single-phase phosphor-converted white LEDs in this work. Herein, we chose whitlockite-type Ca9LiY0.667(PO4)7 compound as a host which provides multiple cation sites for Eu2+ occupation. Spectral results indicate that the Ca9LiY0.667(PO4)7:Eu2+ phosphor emits a cold white emission due to its multiple emission bands at about 420, 480, and 530 nm, which correspond to emissions from the M(3), M(1)/M(2) and M(5) cation sites as ascertained by the Rietveld refinement method. In order to enhance the red emission of CLYPO:Eu2+ phosphors, they were codoped with Mn2+. Warm white emission in a single-phase host based on energy transfer was successfully obtained in the CLYPO:Eu2+,Mn2+ phosphors. The excitation band of the CLYPO:Eu2+,Mn2+ phosphors in the 360 to 450 nm range perfectly coincides with that of commercial LED chips, implying that these phosphors are desirable for white LED applications. White LEDs with a higher color rendering index (Ra = 90.2) and a lower correlated color temperature (CCT = 3614 K) were achieved by using a single-phase CLYPO:0.03Eu2+,0.10Mn2+ phosphor and a 395 nm InGaN-LED chip. [ABSTRACT FROM AUTHOR]

The Transbaikal-Mongolia-North China province of East Asia is ranked as the most productive uranium province. Its area contains hundreds of occurrences, dozens of deposits of different (endo-, exo-, and polygenic) types, and several large uranium-bearing clusters and districts. The largest F-Mo-U clusters were revealed in the Mongol-Argun and Inshan-Liaohe volcanoplutonic zones (VPZ) in the western and southwestern periphery of the Great Xingan belt, respectively. Tectonic data on the Late Mesozoic (J2-K) Tulukuev (Southeastern Transbaikalia), Dornod (East Mongolia), and Guyuan-Duolung (Inshan-Liaohe, China) depressions of the above-mentioned VPZ are analyzed to distinguish their important structural details, which are responsible for the distribution of uranium-bearing fields and deposits in the volcanic rocks. Some of the deposits are associated with paleovolcanic necks, extrusive rocks, subvolcanic bodies, and dikes and have complex morphology. Other deposits are localized in stratified volcanic-pyroclastic rocks or within the basement rocks of the depressions. Recent geochronologic, geophysical, and seismotomographic data indicate not only the synchronous formation of the ore clusters in the Early Cretaceous (Valanginian), but also their localization within a crust of moderate (36-42 km) thickness above the periphery of a stagnant slab in the mantle transition zone. The coincidence of the slab boundary projections and area of their influence with the spatial position of large F-Mo-U ore clusters (Streltsovka, Dornod, and Guyuan-Duolung) separated from each other by hundreds and thousands of kilometers is regarded as evidence for the possible influence of deep geodynamics on the formation of the corresponding mineralization. Some of the aforementioned and similar clusters of the province seem to be insufficiently studied. This refers, in particular, to the exploration of the thick volcanic-pyroclastic fields associated with volcanic paleocenters within the clusters, as well as the basement rocks of the basin. [ABSTRACT FROM AUTHOR]

Single crystals of Ca9Y(VO4)7 (1), Ca9Y(VO4)7:Li+ (2) and Ca9Y(VO4)7:Mg2+ (3) were grown by the Czochralski method. Their chemical composition was analyzed by ICP spectroscopy and their crystal structure was examined by single crystal X-ray analysis. The crystals are characterized by trigonal symmetry, space group R3c. Hexagonal unit-cell parameters are as follows: a=10.8552(1) Å, c=38.0373(2) Å, V=3881.65(1) Å3 for 1; a=10.8570(1) Å, c=38.0161(3) Å, V=3880.77(4) Å3 for 2; a=10.8465(1) Å, c=38.0366(2) Å, V=3875.36(3) Å3 for 3. All crystals are characterized by β-Ca3(PO4)2-type structure with statistical distribution of Ca2+ and Y3+ over M1, M2 and M5 sites in different ratios and with completely empty M4-cationsite. The impurity of Mg2+cations in structure 2 has been detected in octahedral M5 site. Ferroelectric phase transitions are evidenced by DSC and SHG. At about 1220 and 1300 K, they demonstrate phase transitions. Upon heating the symmetry of the crystal structure changes according to the scheme R3c→R3̅c→R3̅m and is restored during consequent cooling. The first of them is of ferroelectric and the second of non-ferroelectric nature. Even a small amount of impurities in Ca9Y(VO4)7 structure is accompanied by a noticeable decrease in the temperature of the ferroelectric-paraelectric phase transition. [ABSTRACT FROM AUTHOR]

We present the results of experimental studies of propagation of the low-frequency pulsed signals in the deep-water region of the Indian Ocean under conditions of a waveguide open from the bottom side when the signal from a near-surface source, which is received by the near-bottom receiver, is a sequence of reflections from the bottom and the ocean surface. The spatiotemporal diagram showing the amplitudes of the received pulses as functions of the distance and the relative time of their arrival is used for the data processing. It is shown that using a simple model of the stratified waveguide with a constant bottom and geometrical-optics approximation for calculating the tone-signal field, one can achieve good agreement between the experimental and theoretical results. In particular, this allows one to determine the effective waveguide depth for the frequency range 5-40 Hz and estimate the reflecting-boundary characteristics. The obtained results can also be used for predicting the parameters of the low-frequency signal propagating in the waveguides of this kind. [ABSTRACT FROM AUTHOR]

A significant change in the properties of mountainous meadow soils of the Ai-Petri Plateau has taken place under the impact of artificial plantations of pine, birch, and larch created in the Crimean highlands in the middle of the 20th century. In comparison with the soils under meadow vegetation, the soils under forest vegetation are characterized by an increased content of large aggregates, a decrease in the humus content, and an increase in the soil acidity and in the iron content of the organomineral compounds. The most dramatic changes in the structural state of the soils are observed under the plantations of pine. The changes in the acidity and the iron content are most pronounced under larch stands. The decrease in the humus content is observed under all tree species. Thus, in the soil layer of 0-10 cm under pine, birch, and larch stands, the content of Corg is 1.2, 1.3, and 1.4 times lower, respectively, than that in the soil under meadow vegetation. [ABSTRACT FROM AUTHOR]

Contrast variations in the type of REE distribution from a distinctly negative mode to a positive mode is revealed in zonal fluorites of Eastern Transbaikal, with a pronounced decrease in the Ce/Y ratios in successive zones of increasing Y accompanied by a gradual decrease in the temperature and salinity of fluid inclusions in the fluorites. It is assumed that these facts are caused by the appearance of nm-size phases of REE minerals characterized by various crystalline structures and demonstrating selective concentrations of lanthanides, i.e., exhibiting a crystal-chemical differentiation of REEs that is widespread in the processes of mineral formation. Based on this natural mechanism, the development of a procedure of selective REE extraction from the concentrates is proposed. The primary laboratory experiments resulted in the discovery of the difference in REE concentrations in the sediment and filtrate with the separation coefficient varying by a factor of 76. The results obtained allow one to expect a true separation possibility for Nd along with the medium and heavy REEs. In view of the data obtained, the crystalline-chemical separation of REEs has some advantages compared to the processes currently used, especially extraction. [ABSTRACT FROM AUTHOR]

This work presents the results of U-Pb geochronological studies of alkaline granites of the Aralaul complex of Northern Kazakhstan, which allow one to substantiate their Late Silurian (420 ± 4 Ma) age. Taking into consideration the previously obtained data, we propose a new development scheme of Paleozoic granitoid magmatism in Northern Kazakhstan, which includes Late Ordovician granite-granodiorite (Zerenda and Krykkuduk), Early Silurian granite-leucogranite (Borovoe and Karabulak), Late Silurian granosyenites-granite (Aralaul), and Early Devonian (Balkashino and Orlinogorsk) complexes. [ABSTRACT FROM AUTHOR]

The paper considers the problem of monostatic scattering of low-frequency sound waves by nearsurface volumetric inhomogeneities under conditions of intense wind waves. We calculate the expected shape of the scattered signal spectrum taking into account the distribution of the volumetric inhomogeneities over the surface and their quasiperiodic motion in three-dimensional space under the action of wind waves. For deep-ocean conditions, a carrier frequency of 228 Hz, and a pulse duration longer than 100 s, we compare the experimental data on the shape of the reverberation spectrum with theoretical estimates. We compare the spectral levels of subsurface scattering with similar data on sound scattering directly on the wind-roughed surface. [ABSTRACT FROM AUTHOR]

Copyright of Eastern-European Journal of Enterprise Technologies is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of an external magnetic field on the Jahn-Teller phase transition at Tc ≈ 14K was studied in a KDy(MoO4)2 single crystal. At temperatures below Tc a significant change in the velocity and attenuation of the acoustic modes of the crystal was observed for the magnetic field oriented along the [110] direction. This behavior of the elastic characteristics occurs due to the destruction of the antiferrodistortive ordering, which is, in turn, coupled with the ordering of the quadrupole orbital moments, characteristic for an "orbital nematic." The low-temperature region of the H-T phase diagram for this direction of the field was reconstructed. It was found that the magnetic field dependence of the critical temperature is nonmonotonic, i.e., the phase transition has the reentrant character. Theoretical description of the observed anomalies of the temperature and magnetic field behavior of the acoustic characteristics was given. [ABSTRACT FROM AUTHOR]

The enrichment of lead isotopic composition of nonuranium minerals, in the first place galena in 206Pb and 207Pb, as compared to common lead is a remarkable feature of uranium deposits. The study of such lead isotopic composition anomalous in 206Pb and 207Pb in uranium minerals provides an opportunity for not only identification of superimposed processes resulting in transformation of uranium ores during deposit history but also calculation of age of these processes under certain model assumptions. Galena from the Chauli deposit in the Chatkal-Qurama district, Uzbekistan, a typical representative of hydrothermal uranium deposits associated with domains of Phanerozoic continental volcanism, has been examined with the highprecision (±0.02%) MC-ICP-MS method. Twenty microsamples of galena were taken from polished sections. Six of them are galena hosted in carbonate adjacent to pitchblende spherulites or filling thin veinlets (approximately 60 µm) cutting pitchblende. Isotopically anomalous lead with 206Pb/204Pb and 207bPb/204Pb values reaching 20.462 and 15.743, respectively, has been found in these six microsamples in contrast to another fourteen in which the Pb-Pb characteristics are consistent with common lead. On the basis of these data and with account for the 292 ± 2 Ma age for the Chauli deposit, the age of epigenetic transformation of uranium ores of this deposit has been estimated. During this process, radiogenic lead partly lost from pitchblende was captured into galena. The obtained date is 170 Ma. In the Chatkal-Qurama district, these epigenetic processes are apparently caused by the interaction of uranium minerals with activated underground water under tectonic activity and relief transformation, which took place from the post-Permian (i.e., after the Chauli formation) to the Jurassic period. [ABSTRACT FROM AUTHOR]

Copyright of Eastern-European Journal of Enterprise Technologies is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technology Audit & Production Reserves is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present work is devoted to solving the tasks aimed at the study of pressure-driven membrane processes used in the manufacture of ultrafiltration cottage cheese via microfiltration followed by ultrafiltration using membranes of domestic manufacture. As a result of this study, the technological parameters of baromembrane processes (speed of solution over the membrane, operating pressure, and temperature) providing the maximum productivity and selectivity of the microbiological clearance of skim milk by microfiltration and the ultrafiltration concentration of curd have been determined. The possibility of affecting the characteristics (permeability and selectivity) of the ultrafiltration process by approaching the isoelectric point of the protein fraction due to the change in the active acidity of the curd under concentration has been considered. The applicability of the microfiltration process in cottage cheese making has been confirmed, since it leads to enhancement of the performance of ultrafiltration membranes and increases the shelf life of the resulting product. [ABSTRACT FROM AUTHOR]

The paper considers the problem of backscattering of sound waves by near-surface volumetric inhomogeneities under conditions of intense wind waves. We calculate the expected share of the scattered signal spectrum based on the given wind-wave intensity and the depth distribution of volumetric inhomogeneities. For deep ocean conditions in the frequency range of 500-1000 Hz for a pulse duration of 10 s, we measure the levels and shape of the reverberation spectrum for time delays from 20 to 100 s. Comparison of the measured and calculated reverberation spectra has shown their good coincidence. [ABSTRACT FROM AUTHOR]

The effects of normobaric hypoxic hypoxia (single-session and interval training) on the sensory-cognitive features of auditory perception in humans were studied. Audibility thresholds (pure tone audiograms) were determined, along with the psychophysical properties of auditory analysis (detection of pauses in the sound signal, discrimination of rhythm, extraction of the target word in 'verbal cocktail' conditions), and the volume of short-term auditory memory before and after hypoxia. Qualitative and quantitative changes were found in measures of the subjects' sensitivity, memory, and reaction speed. A positive effect of interval hypoxic training on the processes of auditory perception was found. [ABSTRACT FROM AUTHOR]

Fig oil is a nutritious vegetable based oil type which is rich in polyunsaturated fatty acids. In the present study, several attempts have been made to produce encapsulated oil with maximum efficiency. In the first step, the effect of feed concentration was observed at 140, 150 and 160 °C and 20 % dry matter was selected. In the second step, distribution of gum arabic (GA) and maltodextrin (MD) as a wall material was determined at different temperature levels (140, 150, 160, 170 and 180 °C), and optimum MD/GA ratio and temperature were found to be 8/1 and 150 °C, respectively. In the next step, impact of wall material/fig oil ratio on the encapsulation efficiency was investigated and it was determined to be 3.0. According to the results, optimum encapsulation ratio of MD/GA/oil and temperature were 8/1/3 and 150 °C, respectively. The physicochemical properties; particle size, peroxide value, dry matter content, and encapsulation efficiency of the oil encapsulated under this condition were determined. Water content and water solubility of the powder was determined as 2.875 and 97.85 %, respectively. At the optimum conditions particle of the fig oils showed smooth surface, non-homogeneous and spherical shape, and size of the most of the particles ranged between 8 and 40 μm. [ABSTRACT FROM AUTHOR]

The unique combination of several exogenic processes augmenting uranium mineralization followed one another in time at deposits of the Khiagda ore field and gave rise to the formation of uranium resources exceptional for the paleovalley geologic and economic type. The specific geological evolution, volcanic activity, and regional climatic conditions taken together became the main cause of local occurrence of these deposits. [ABSTRACT FROM AUTHOR]

The evolution of the geological structure in the Southern Argun' Region is studied in terms of changing geodynamic conditions of the Proterozoic, Caledonian, and Variscan Tectonomagmatic Cycles, which also under Mesozoic tectonomagmatic activation led to the formation of latite igneous rocks enriched in Au, Cu-Mo, Pb-Zn-Ag, volcanic and plutonic complexes of the caldera structures with Mo-U, Pb-Zn, and fluorite ores, and rare-metal granites with a Sn-W-Li-Ta spectrum. [ABSTRACT FROM AUTHOR]

The paper studies the patterns manifesting themselves in the formation and propagation of caustic and weakly diverging beams using the geometric acoustic approximation and mode theory applied to the simplest model of an underwater sound channel open to the bottom in the form of the bilinear dependence of the square of the refractive index on depth. It is established that when a vertical array emitting a tonal sound signal is located at a certain critical depth, the multimode caustic beam which forms near the reference ray horizontally departing from its center and which predominates in intensity is simultaneously the most weakly diverging beam. It is shown that the reference ray of such a weakly diverging caustic beam corresponds to the smoothest minimum for the dependence of the length of the ray cycle on their angle of departure from the center of the array and to the depth level of revolution at the critical depth characteristic of the given oceanic waveguide. [ABSTRACT FROM AUTHOR]

This paper discusses the state of the Arctic cryosphere during the second half of the twentieth century and describes major findings of observational evidence since the 1950s. Although glaciers have been retreating steadily from their Little Ice Age maximum positions for decades, Arctic sea ice extent and thickness began to decline and loss of mass from the Greenland ice sheet accelerated only in the 1990s. Rapid changes in cryospheric components have occurred in this century, affecting snow cover, Arctic sea ice extent, the mass balance of the Greenland ice sheet, and frozen ground temperatures. Projections for this century, based on model results from the Intergovernmental Panel on Climate Change, involve dramatic changes by 2100. [ABSTRACT FROM AUTHOR]

As a result of integrating geological, mineralogical, and geochemical data on the unique Schlema-Alberoda five-element uranium deposit situated in Federal Republic of Germany and explored in detail down to a depth of 2 km, it has been shown that its formation for more than 100 Ma has been caused by combination of internal and external factors. The latter comprise favorable metallogenic specialization of the region, injection of intrusive bodies bearing the necessary stock of energy, and periodic pulses of tectonic reactivation. The internal factors of self-development involve evolutionary processes, which occur in host rocks at the consecutive stages of prograde and retrograde metamorphism giving rise to alteration of rocks in consistence with physical and chemical laws at variable temperature and degree of system opening. [ABSTRACT FROM AUTHOR]

Here we disclosed the substantial effect of the local medium in the vicinity of the excited Nd3+ions on the optical properties and the laser characteristics of glasses. The UV-Vis absorption of the laser BaO/SrO–P2O5–Al2O3–K2O–B2O3–La2O3glasses doped with Nd3+ions is measured at 25 °C. Judd-Ofelt (JO) theoretical analysis of 4f electron transitions in the Nd3+absorption spectra was performed. From the JO intensity parameters, a set of the laser4F3/2→4I11/2transitions characteristics are found and stimulated emission cross-sections are characterized. The effect of different Ba/Sr ratio on the structure-properties relationships in the glasses is shown. [ABSTRACT FROM AUTHOR]

The possibility of using hydrothermal fluorite as an Sm-Nd geochronometer is based on the results of an REE pattern study of this mineral (Chernyshev et al., 1986). As a result of REE fractionation, in many cases, the Sm/Nd ratio achieves a multifold increase compared with its level in terrestrial rocks, and the radiogenic shift of the Nd/Nd isotope ratio reaches 10-20 ε units over a short time interval (as soon as tens of Ma). This is a necessary prerequisite for Sm-Nd isochron dating of fluorite. Zonal polychrome fluorite from a vein referred to the final stage of large-scale uranium mineralization at the Sterl'tsovka deposit in the ore field of the same name located in the eastern Transbaikal region has been dated using the Nd/Nd method. To optimize isochron construction, local probes with high and contrasting Sm/Nd ratios have been sampled from the polished surfaces of two samples, taking into account the REE pattern of zonal fluorite. Sm-Nd isochron dating has been carried out separately for each sample. The Sm/Nd и Nd/Nd ratios vary within the intervals 0.5359-2.037 and 0.512799-0.514105, respectively. Two isochrons, each based on six fluorite probes, have been obtained with the following parameters, which coincide within 2σ uncertainty limits: (1) t = 134.8 ± 1.3 Ma, (Nd/Nd) = 0.512310 ± 13, MWSD = 0.43 and (2) t = 135.8 ± 1.6 Ma, (Nd/Nd) = 0.512318 ± 10, MWSD = 1.5. The mean age of fluorite based on two isochron datings is 135.3 ± 1 Ma. Comparison of this value with the most precise dating of pitchblende related to the ore stage in the Strel'tsovka ore field (135.5 ± 1 Ma) shows that four mineralization stages, distinguished by geological and mineralogical data, that were completed with the formation of polychrome fluorite veins 135.3 ± 1 Ma ago, represent a single and indivisible hydrothermal process whose duration does not exceed 1 Ma. [ABSTRACT FROM AUTHOR]

The results obtained in Russian studies on clouds and precipitation in 2011-2014 are presented. These results are part of the Russian National Report on Meteorology and Atmospheric Sciences that was prepared for the XXVI General Assembly of the International Union of Geodesy and Geophysics (IUGG). [ABSTRACT FROM AUTHOR]

Copyright of Eastern-European Journal of Enterprise Technologies is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Data on sampling long-term monthly mean distributions of Antarctic sea ice extent are analyzed for the period of 1974-2013. In the framework of propositions on the nature of variations in the components of limited-area system, the numerical model of sea ice extent dynamics was developed. It is demonstrated that in 1974-2013 the variations in monthly mean sea ice extent were defined by semiannual, annual, 30-year, and 60-year periodic components. The interpolation of the obtained results is presented. The forecast of Antarctic sea ice conditions for 2015-2135 is given. [ABSTRACT FROM AUTHOR]

Trends in the anthropogenic transformation of the taxonomic structure of the native flora in the southern Volga Uplands (within the Saratov region) are analyzed. The temporal dynamics of this structure in three local types of flora was studied over the past 100 years. The degree of tolerance of the flowering plant taxa in the studied flora to the full range of anthropogenic habitats and to their individual types is shown. The proportion of species characterized by anthropogenic geographical migration was estimated for each taxon. It is suggested to use the percentage ratio of species in the Magnoliophyta classes as an indicator of the degree and stage of anthropogenic transformation of the flora. [ABSTRACT FROM AUTHOR]

The red-emitting Ca9Eu(PO4)7 nanophosphors have been successfully synthesized by a facile hydrothermal method. X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, GSAS structural refinement and scanning electron microscopy (SEM) were used to characterize the materials. Rietveld refinement of powder X-ray diffraction patterns of Ca9Eu(PO4)7 demonstrated that the structure of Ca9Eu(PO4)7 consisted of [PO4] tetrahedra. Ca/Eu atoms filled the space between the tetrahedral groups with Eu3+ ions distributed randomly on three individual Ca crystallographic sites. The major red emission peak located at 616 nm under 397 nm excitation attributed to the electric dipole transition 5D0→7F2 of Eu3+ was a parity forbidden f–f configuration transition, which would only occur when Eu3+ occupied lattice sites without inversion symmetry. Introducing Gd, La, and Y ions into samples made luminescence properties of Ca9Eu1−xLnx(PO4)7 (Ln = Gd, La, Y) phosphors decrease. pH value plays a key role in the formation of Ca9Eu(PO4)7 nanophosphor morphology. With increasing pH in the initial reaction solution, the morphology of samples changed from rod to sphere and their aspect ratio also decreased. Different morphologies have different photoluminescence properties, and samples prepared at pH 7 manifested better photoluminescence properties relative to other samples. This novel red-emitting phosphor could be applied in white light-emitting diodes. [ABSTRACT FROM AUTHOR]

According to this paper, the juvenile crust of the Chingiz Range Caledonides (Eastern Kazakhstan) was formed due to suprasubduction magmatism within the Early Paleozoic island arcs developed on the oceanic crust during the Cambrian-Early Ordovician and on the transitional crust during the Middle-Late Ordovician, as well as to the attachment to the arcs of accretionary complexes composed of various oceanic structures. Nd isotopic compositions of the rocks in all island-arc complexes are very similar and primitive (ε(t) from +4.0 to +7.0) and point to a short crustal prehistory. Further increase in the mass and thickness of the crust of the Chingiz Range Caledonides was mainly due to reworking of island-arc complexes in the basement of the Middle and Late Paleozoic volcanoplutonic belts expressed by the emplacement of abundant granitoids. All Middle and Late Paleozoic granitoids have high positive values of ε(t) (at least +4), which are slightly different from Nd isotopic compositions of the rocks in the Lower Paleozoic island-arc complexes. Granitoids are characterized by uniform Nd isotopic compositions (<2-3 ε units for granites with a similar age), and thus we can consider the Chingiz Range as the region of the Caledonian isotope province with an isotopically uniform structure of the continental crust. [ABSTRACT FROM AUTHOR]

The undeformed ore-bearing intrusions of the Noril'sk ore field (NOF) cut through volcanic rocks of the Late Permian-Early Triassic trap association folded in brachysynclines. Due to the nonuniform load on the roof of intrusive bodies, most sulfide melts were squeezed, up to the tops of ore-bearing intrusions; readily fusible Ni-Fe-Cu sulfide melts were almost completely squeezed. In our opinion, not only one but two stages of mineralization developed at the Noril'sk deposits: (i) syntrap magmatic and (ii) epigenetic post-trap metamorphic-hydrothermal. All platinum-group minerals (PGM) and minerals of gold are metasomatic in the Noril'sk ores. They replaced sulfide solid solutions and exsolution structures. All types of PGM and Au minerals occur in the ores, varying in composition from pyrrhotite to chalcopyrite, talnakhite, mooihoekite, and rich in galena; they are localized in the inner and outer contact zones and differ only in the quantitative proportions of ore minerals. The aureoles of PGM and Au-Ag minerals are wider than the contours of sulfide bodies and coincide with halos of fluid impact on orebodies and adjacent host rocks. The pneumatolytic PGM and Au-Ag minerals are correlated in abundance with the dimensions of sulfide bodies. Their amounts are maximal in veins of late fusible ore composed of eutectic PbS ss and iss intergrowths, as well as at their contacts. The Pd and Pt contents in eutectic sulfide ores of NOF are the world's highest. In the process of noble-metal mineral formation, the fluids supply Pd, Pt, Au, As, Sb, Sn, Bi, and a part of Te, whereas Fe, Ni, Cu, Pb, Ag, Rh, a part of Te and Pd are leached from the replaced sulfide minerals. The pneumatolytic PGM of the early stage comprises Pd and Pt intermetallic compounds enriched in Au along with Pd-Pt-Fe-Ni-Cu-Sn-Pb(As) and (Pd,Pt,Au)(Sn,Sb,Bi,Te,As) solid solutions. Pneumatolytic PGM and Au minerals of the middle stage are products of solid-phase transformation and recrystallization of early PGM in combination with the newly formed mineral species Sb-paolovite-insizwaite-geversite-maslovite, niggliite, tetraferroplatinum, rustenburgite-atokite-zvyagintsevite, moncheite, majakite, plumbopalladinite, polarite in association with altaite. The late minerals of the middle stage include stannopalladinite, tatianaite-taimyrite, Ag-Pd-Pt tetraauricupride, and cuproauride. PGM and Au-Ag minerals of the late stage are represented by sobolevskite-sudburyite-kotulskite, maslovite-michenerite, low-Sb paolovite, hessite, cabriite, Au-Ag minerals with fineness of 870-003, froodite, Sb-free insizwaite, Bi-free geversite, and Sb-free niggliite. Electrum and küstelite in PGM aggregates are not zoned. Crystals of Au-Ag minerals that grow over PGM minerals are smoothly zoned. Their zoning may be direct (crystal margins are enriched in Ag), inverse, oscillatory, and complex. Despite favorable annealing conditions, exsolution structures are not identified in Au-Ag minerals from the Noril'sk ores. Sperrylite-the latest of pneumatolytic PGM-occurs as metacrysts up to 14 cm in size. Sperrylite, which replaces high-Sb minerals, contains up to 11 wt % Sb. Pneumatolytic noble-metal minerals originated under the effect of the fluids released during crystallization of sulfide melts in an extremely reductive setting and at extremely low fS; temperature drops from ~450 to ~350°C. Metamorphic-hydrothermal Ag mineralization (native silver, Hg-silver, sulfides and selenides, chalcopyrite-lenaite solid solutions, argentopentlandite), Pd mineralization (vysotskite, palladoarsenide, vincentite, Sb-free Ag-paolovite, malyshevite, native palladium), and Pt mineralization (kharaelakhite, cooperite, native platinum) develop in those parts of orebodies that are affected by low-grade metamorphism. [ABSTRACT FROM AUTHOR]

Based on available experimental data, a computer model was developed for the description of chlorine distribution between a magmatic melt of metaluminous granite composition and an aqueous chloride fluid phase formed during the decompression degassing of magma at pressures ranging from 5 to 0.5-0.3 kbar and temperatures of 800 ± 25°C. The model accounts for the dependence of fluid/melt Cl partition coefficient on pressure and Cl content of the melt. It allows the calculation of Cl and HO redistribution between melt and fluid during the decompression degassing of magmas under both closed-system conditions, when fluid remains in the system, and open-system conditions, when the released fluid phase is completely of partly removed from the system. The results of numerical modeling revealed the influence of the initial Cl and HO contents in melt and the degree of system openness on variations in the concentrations of these volatiles in aqueous fluid and melt during magma ascent toward the surface under near-isothermal conditions. The highest Cl concentrations of the fluid ( C) are attained at the early stages of decompression degassing at high pressures. With decreasing pressure, C decreases at a rate that increases at increasing degree of system openness. During open-system degassing, the Cl content of melt ( C) also decreases. In contrast, under closed-system conditions, C decreases initially with decreasing pressure, reaches a minimum, and then increases. If decompression degassing begins at P ≤ 1.0-1.25 kbar, C changes only slightly irrespective of the initial Cl content of the melt and the degree of system openness. [ABSTRACT FROM AUTHOR]

We consider the patterns in the formation of the spatial interference structure of an acoustic field excited in the near-surface channel of a vertical array consisting of point sources emitting a tonal signal inphase. It is established that when the array aperture is increased to a certain optimal size, only one caustic beam forms in the channel. As the array aperture further increases, the sequential formation of a certain number of beams after the first is observed. [ABSTRACT FROM AUTHOR]

A novel phosphate Ca9La(GeO4)0.75(PO4)6 was investigated to add to the family of phosphate phosphors and application in LEDs. In this work, the single phase red-emission Ce3+,Mn2+ co-doped phosphate Ca9La(GeO4)0.75(PO4)6 phosphor was synthesized by the solid-state reaction from both theoretical and practical points of view. The crystal structure was determined by Rietveld refinement and TEM. Its cell parameters are a = b = 10.4077605(2) Å, and c = 37.4714968(1) Å. The characteristic photoluminescence properties were studied in detail using photoluminescence excitation spectra, emission spectra, decay times and thermal quenching properties. Purple and red broad band emission from Ce3+ and Mn2+ was detected under excitation at 313 nm. According to this research, the Ca9La(GeO4)0.75(PO4)6:Ce3+,Mn2+ phosphor shows high thermal stability in the red-emission area. With the increase of the temperature, the intensity ratio of Mn2+ and Ce3+ emission rises rapidly and the purity of red-emission is improved. In order to reasonably explain this special phenomenon, an implicit mechanism between thermal quenching and energy transfer is proposed based on the configurational coordinate diagram. In addition, the mechanism could be helpful for understanding the thermal properties of multiple activators Ce3+ and Mn2+ co-doped phosphors as the reference. [ABSTRACT FROM AUTHOR]

Yttrium ( Y)-based bioceramics are important materials in radiation therapy and biomedical applications. This paper describes a low-temperature method to prepare yttrium phosphate ( YPO4) and Y-doped calcium phosphate (Y-CaP) microspheres using CaP microspheres as template. The as-formed microspheres were characterized using X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy, confirming the formation of YPO4 and Y-CaP microspheres. The process was based on the dehydration effect of ethanol to CaP materials and hydrated ions transportation in amorphous CaP microspheres. The procedure, owing to its simplicity, may provide a new sight for the preparation of Y or rare earth elements-based bioceramic materials. [ABSTRACT FROM AUTHOR]

Developed is the large-scale model of the dynamics of the Arctic sea ice cover area based on the formal concepts of the dynamics of the components of the limited-area binary system. Proposed is the technique for its parametric identification. It is demonstrated that the distribution of the monthly mean values of the sea ice area for the period of 1972-2013 is defined with the high degree of accuracy as being close to the seasonal, annual, and 60-year components. Presented is the forecast of the sea ice area for 2014-2113. [ABSTRACT FROM AUTHOR]

This work presents the results of complex analysis of the field data and of mathematical modeling of the ice ring structure more than 4 km across, which was identified by the space images of South Baikal in April 2009. The measurements revealed that the ice thickness was 74 cm in the center of the structure, decreased to 43 cm at a distance of 2 km, and increased up to 70 cm and more beyond the ring. The ice water in the central part was warmer by 0.5°C and less saline (for 2 mg/kg) relative to the periphery of the structure. According to the tracer movements, the maximum velocities of the ice currents (3-4 cm/s) were observed at a distance of 2-3 km from the center of the structure with minimum ice thickness. The event was modeled using several mathematical models of various scales. The 3-D nonhydrostatic modeling of the large-scale processes on the basis of the temperature measured in the area of the structure showed the presence of local anticyclonic circulation, where the velocities of the currents increased up to the maximum (5-7 cm/s) at the distance of 2-3 km from the center and then decreased. The variations in the ice thickness in the area of the ring structure were modeled on the basis of these calculation results. The ice thicknesses determined in the context of the Stefan problem for the 2-D axis-symmetrical temperature distribution model are close to the measured ones. According to the model, the formation of the ring structure spans a period of 25-35 days. The origination of the dark ring on the satellite images is related to the lower ice thickness relative to the ambient areas and to the water level in microfractures closer to the ice surface. [ABSTRACT FROM AUTHOR]

Wave propagation in a near-bottom layer containing gas bubbles is analyzed. Evolution equations are derived for intense acoustic waves and wave beams in a medium with an inhomogeneous bubble distribution. The field of an intense beam along the axis of the focusing sound channel is calculated. The coefficients of reflection and passage of sound from a homogeneous medium into a bubble layer and back again are calculated. It is shown that the near-bottom layer can effectively trap rays incident on it and ensure a waveguide propagation character. The presence of bubbles increases both the interval of angles at which the wave penetrates the layer and the interval of angles at which rays undergo total internal reflection and do not depart the layer. The acoustic field in the layer from a point source is calculated. [ABSTRACT FROM AUTHOR]

A method is developed for passive acoustic diagnostics of a mobile sound source in an oceanic waveguide, based on information on the frequency shifts of the maxima of the wave field and mode eigen-functions. An algorithm is formulated for solving the inverse problem. A numerical experiment demonstrates the possibilities of this method for reconstructing the trajectory, velocity, and depth of a source. [ABSTRACT FROM AUTHOR]

An original database, which was compiled by the authors, is continuously updated, and now contains data from more than 19 800 publications on fluid and melt inclusions in minerals, was utilized to review and synthesize data on the physicochemical parameters at which hydrothermal uranium deposits and occurrences were formed. The parameters discussed below are temperature, pressure, density, salinity, gas composition of the fluid, and U concentration in the hydrothermal fluid. The database contains data of fluid inclusions in minerals from 90 U deposits and occurrences worldwide. Histograms of the homogenization temperatures of fluid inclusions are presented for such typical minerals of these deposits and occurrences as quartz, calcite, and fluorite. The temperature range most favorable for the origin of U deposits is 100-200°C (67% of the 937 measured temperature values fall within this range), which makes U deposits remarkably different from higher temperature Au-Ag, W, and Sn deposits. These deposits also differ in the salinity of the fluids. The range of fluid salinity of 10-30 wt % equiv. NaCl includes 42% of fluid salinity values measured at U deposits (our database includes 937 measured values), 27% for Au-Ag deposits (10 237 measured values), 27% for W deposits (2333 measured values), and for Sn deposits (1981 measured values). The relatively low temperature of U-bearing fluids and their high salinity testify that these solutions had a high density: 94% of all measured values lie within the range of 0.8-1.2 g/cm. Fluid pressure at U deposits broadly varied from 2500 to 300 bar and perhaps even lower values. Data on the chemical composition of the gas phase of the fluid inclusions show a significant diversity of the fluids contained in the inclusions. In certain instances, HO-CO fluids give way to fluids rich in CH and N with minor amounts of hydrocarbons. Data are reported on the gas composition of fluid inclusions in the nuclear-reactor zone at three Precambrian U deposits. Analyses of individual inclusions were utilized to evaluate U concentrations in magmatic melts and mineral-forming fluids. The geometric mean U concentration in silicate melts of composition ranging from ultramafic to silicic is 0.92 ppm (8053 measured values), and the analogous values for the fluids is 1.21 ppm (271 measured values). [ABSTRACT FROM AUTHOR]