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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.

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.

We present the results of experiments on measuring the characteristics of a wideband low frequency (10-200 Hz) acoustic field in an inhomogeneous shallow-water waveguide in the Barents Sea area. Correlation functions of the signals received by hydrophones of autonomous bottom stations with independent reception, which are horizontally spaced 18 and 112 km apart, are measured. A pneumoacoustic radiator with an overpressure of 10.5 MPa and a volume of 7.5 l was used as a sound source. During the measurements, the signal source was shifted from the line of receivers to distances 10-225 km. The dependences of the correlation coefficient of the received signals on the radiation frequency and the interferometer-baseline length and orientation are studied. It is shown that pronounced local minima in the interval 10-40 Hz due to the difference of the inhomogeneities in the propagation channels and, therefore, the frequency characteristics of the medium are present in the frequency dependences of the correlation coefficient against the background of a monotonic decrease with increasing frequency.

The composition and amounts of liposoluble substances in the flesh and peel of feijoa fruit has been investigated. About 30 groups of lipid substances have been identified. The main groups of lipids in the flesh were triacylglycerols, sterols, cerebrosides, ceramide phosphate inositol oligosides, sulfoquinovosyldiacylglycerols, phosphatidic acids, phosphotidylglycerols and phosphatidylcholines. In the peel, hydrocarbons, sterols, esters of fatty acids and lower alcohols, cerebrosides, digalactosyldiacylglycerols, ceramide oligosides, phosphatidylglycerols, and include predominated. The fatty acids of the flesh were found to include 15 representatives (C12:0–C28:0), and those of the flesh 11 representatives tives (C12:0–C18:3).

The carbohydrate complex of the fruit ofChaenomeles maulei contains more than 70% of water-soluble sugars, including sucrose, arabinose, galactose, fructose, and glucose. The bulk of the carbohydrate is represented by water-soluble pectin, and protopectin, hemicellulose, and cellulose. The monomeric compositions of all the fractions of carbohydrates and the ratio between the reducing and inverted sugars have been studied.

The search for new materials with special optical properties, including luminophores, is basically performed empirically. At the same time on the basis of crystallochemical representations by variation of the anionic and cationic compositions of the phases, purposeful synthesis of compounds with a given structure and physicochemical characteristics can be performed. In this direction a low-temperature modification of calcium orthophosphate [i], which is related to the structural type of the natural mineral whitlockite is of definite interest [2].

An equation was obtained for calculating the flow of a gas through a layer of parallel cylinders positioned perpendicular to the direction of gas flow by using the plane channel approximation. The broader applicability of the equation for calculating the gas-dynamic resistance of a layer of fibres in comparison to the published data was demonstrated for the given case of gas flow.

The composition and amounts of the various groups of liposoluble compounds in the rind and flesh of persimmon fruit of the varieties Hachiya and Hyakume have been established by a combination of chromatographic and chemical methods. The identity of the qualitative composition of the lipids of the flesh and rind of the fruit and quantitative differences in the amounts of individual groups have been found. A total of 24 groups of compounds were identified, the main ones of which were monogalactosyldiglycerides, carotenoids, diacylglycerols, ceramide oligosides, digalactosyldiglycerides, phosphatidylglycerols; phosphatidylcholines, and free and glycosylated sterols. In the fatty acid composition of the lipids unsaturated fatty acids — linolenic, oleic, linoleic, and palmitoleic — predominated (>70%).

By chromatographic methods, about 30 groups of various lipid compounds belonging to the classes of neutral lipids, glycolipids, and phospholipids have been identified from the fruit of the fig tree. The main groups are triacylglycerols, free and esterified sterols, mono- and digalactosyldiglycerides, ceramide oligosides, cerebrosides, esterified sterol glycosides, and phosphatidylglycerols. In the fatty acid composition, linoleic, linolenic, oleic, and palmitic acids predominated (>90%).

The compositions and the amounts of various groups of liposoluble compounds in the component elements of the fruits ofCitrus unshiu Marc. [satsuna variety of mandarin orange] — the flavedo, the albedo, the membrane, and the flesh — have been determined by chromatographic and chemical methods. About 30 groups of lipid compounds belonging to the classes of neutral lipids and glyco- and phospholipids have been identified and characterized. The fatty-acid compositions of the main classes of lipids have been studied. About 30 different carotenoids have been determined in the various elements of the satsuma orange.

The fractional compositions of the carbohydrates of the four most promising varieties ofFicus carica L. — Smena, Kadota, Chumlakuri mtsvane, and Turetskii korichnevyi — have been investigated. The qualitative and quantitative monosaccharide compositions of the carbohydrates isolated have been determined. The bulk of the dry matter of the fruit consists of ethanol-soluble oligosaccharides — up to 74.53%. The composition of the residue obtained after the fractionation of the carbohydrates has been studied. It contains ligin bound to mineral elements.

The compositions of the various groups of liposoluble compounds in the peel and flesh of the fruitPyrus communis of the varieties Williams and Bere Ardanpon have been established and their amounts have been determined by chromatographic and chemical methods. The qualitative compositions have been shown to be identical and characteristic quantitative differences have been found in the lipids of individual elements of these pairs. The fatty acid compositions of the lipids have been studied.

V. G. Savinov and S. E. Kudritskaya, in: Proceedings of the IVth All-Union Seminar on Biologically Active (Medicinal) Substances of Fruits and Berries [in Russian], Miturinsk (1972), p. 562. B. H. Davies, in: Chemistry and Biology of Plant Pigments (ed. T. W. Goodwin) 2nd ed., Wiley, New York, Vol. i (1976), p. 870. V. N. Karnaukhov, The Functions of Carotenoids in Animal Cells [in Russian], Moscow (1973). R. F. Taylor, A. D. Little, and A. Park, Adv. Chromatogr. 22, 159 (1983). N. V. Berezovskii, The Chemistry of the Vitamins [in Russian], Moscow (1973).