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Abstract To assess the nature of the post-ore behaviour of uranium in the Namaru deposit (Khiagda ore field), U–Pb isotope systems and the isotopic composition of uranium (234U/238U and 238U/235U) were studied. The studied samples represent different ore zones of the deposit and were collected along cross-sections both vertically and horizontally. Wide variations in the isotopic composition of uranium and U–Pb isotopic age have been established. Deviations of the 234U/238U ratio from equilibrium values, which for some samples exceed 50%, along with significant variations in the isotopic age, indicate that permafrost layer, which covered the catchment areas of paleovalleys with meteoric oxygen-containing waters ca. 2.5 Ma ago, did not lead to preserving uranium ores at the deposit. Uranium migration took place during the Quaternary period. The effective combining the U–Pb dating and 234U/238U data in assessing the post-ore redistribution of uranium made it possible to recognize: removal of uranium from some zones of the ore body and its accompanying redeposition in others. Wide variations in the 238U/235U (137.484–137.851) ratios throughout the entire studied cross-sections can be explained by the different locations of samples relatively to the ore deposition front and change in redox conditions as this front advanced. Depletion of the light isotope 235U in the lower zone of the ore body may be associated with the influence of ascending carbonic waters established in the regional basement. The effect of such waters on uranium-bearing rocks causes predominant leaching of light 235U.

Geochronological studies have been conducted for ore-hosting rocks (quartz rhyolites, felsitic rhyolites, porphyry granites) of some U deposits of the Yakshi-Yangistau complex within the Balkashino ore center of the Northern Kazakhstan uranium province. According to geological maps of various scales, the rocks were traditionally ascribed to the Early–Middle Devonian (quartz and felsitic rhyolites) and Middle–Late Devonian (porphyry granites). The results of U–Pb, Rb–Sr, and K–Ar dating have shown that, according to the current version of the Geochronological Chart, the age of quartz rhyolites is Early–Late Silurian and that of felsitic rhyolites and porphyry granites is Late Silurian. The features of the chemical composition and different initial Sr isotopic composition of these rocks suggest that quartz rhyolites, felsitic rhyolites, and porphyry granites of the Yakshi-Yangistau complex are hardly comagmatic. They are characterized by different ages and formed from independent magmatic sources. Our data indicate the minimum possible age of the formation of primary U ores within the Balkashino ore center.

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.

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 207Pb/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.

Three groups of industrial uranium deposits that differ in the distribution of lanthanides in U oxides have been recognized. A dependence of the REE distribution type on the Yttrium content and Yttrium index YI = (La + Ce)/Y that controls the formation of REE phases capable of selective accumulation of lanthanides has been discovered. This indicates the important role of crystal–chemical fractionation in the distribution of lanthanides. Preferable accumulation of Sm–Gd by U oxides has been found to occur at relatively low contents of Y. In Proterozoic uranium deposits, the yttrium specialization of oxides predominates, while in most Phanerozoic deposits the lanthanum–cerium specialization is typical. These results extend the possibilities of using REEs in ores for purposes of study of the genesis of various uranium deposits.

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.

The uneven character of the distribution of 18O/16O and 234U/238U values was established in the vertical cross section of the productive sequence of the Dybryn uranium deposit (Vitim uranium-ore region, Buryatia). Both a deficiency and an excess of 234U in relation to the equilibrium 234U/238U ratio in the vertical sequence may provide evidence for the extremely low rate of the infiltration water flow. The behavior of oxygen isotope characteristics for different size fractions of terrigenous rocks provides evidence for active uranium redistribution and openness of the isotope system of this element during interaction of terrigenous–sedimentary rocks with infiltration waters.

Nucleation of ice crystals in atmosphere is a result of condensation of water vapor on aerosol particle surface and heterogenic crystallization of the overcooled water micro-aggregations on surface irregularities. Crystal habit of ice nucleus and very small crystals (10 2 nm) corresponds to Gibbs–Wolf theorem and Thomson-Gibbs equation. Consequent growth of nucleated crystal is possible under condition of exceeding of water vapor concentration in atmosphere over the equilibrium vapor concentration over ice crystal. This equilibrium concentration for each crystal facet can be characterized by Clausius–Clapeyron relation with regard to its surface energy. The diagram of atmospheric ice crystals morphology in dependence from absolute and relative vapor supersaturation of atmosphere is developed. It is determined that the relation of height H and diameter D of atmospheric crystals increases at a growth of relative supersaturation, Δ c i /c i , but increases at a growth of absolute supersaturation, Δ c i = c i – c a . The alteration of H/D occurs gradually, which explains conditional character of delimitation on types on the base of this index. The field of absolute and relative supersaturation it is possible to subdivide relatively index H/D value in two parts: columnar forms area, where index H/D > 0.89 and lamellar forms area, where H/D < 0.89. Columnar and needle forms it is possible to characterize as low temperature forms, but lamellar, short-columnar and irregular forms – as high temperature forms. The variety of atmospheric crystal forms is subdivided on four basic groups: solid lamellar, solid columnar, dendrite lamellar and hollow columnar.

The variations in 238U/235U values accompanying mobilization of U by fracture waters from uranium-bearing rocks, in which U occurs as a fine impregnation of oxides and silicates, were studied by the high-precision (±0.07‰) MC–ICP–MS method. Transition of U into the aqueous phase in the oxidized state U(VI) is accompanied by its isotope fractionation with enrichment of dissolved U(VI) in the heavy isotope 238U up to 0.32‰ in relation to the composition of the solid phases. According to the sign, this effect is consistent with the tendency of the behavior of 238U and 235U upon interaction of river waters with rocks of the catchment areas [11] and with the effect observed during oxidation of uraninite by the oxygen-bearing NaHCO3 solution [12].

The 238U/235U ratio was precisely measured in uranium minerals from 11 hydrothermal deposits of different geologic settings and ages situated in ore regions of Asia, Europe, Africa, and North America by MC-ICP-MS using a 233U-236U double spike. The spike was calibrated in reference to the CRM-112A standard with 238U/235U = 137.837 ± 0.015 (Richter et al, 2010). The long-term reproducibility of 238U/235U measurement was estimated as ±0.07‰ by the analysis of monitor samples and the IRMM-3184 standard. The analyses were performed using 0.02–0.04-mg microsamples of uraninite, pitchblende, and coffinite, which were locally extracted from polished sections under an optical microscope. The 238U/235U values obtained for 50 samples of U-bearing minerals range from 137.703 to 137.821, with a 0.86‰ difference and a mean 238U/235U value of 137.773 ± 0.056 (±2SD). The range of 238U/235U variations in seven deposits with uraninite is 0.41‰, which is twice as low as for the deposits with pitchblende-dominated ores. Our study provided the first results for 238U/235U variations in minerals from individual deposits. The largest variations were found in the Oktyabr’skii (Eastern Transbaikalia), Schlema-Alberoda (Erzgebirge), and Shea Creek (Athabasca basin) deposits: 0.70, 0.33, and 0.59‰, respectively. Uranium from the early growth zones of 4–5 mm thick pitchblende spherulitic crusts is isotopically heavier (by 0.22–0.45‰) than uranium from the latest growth zones. A similar isotopic shift in 238U/235U in terms of magnitude (0.31‰) and sense was observed between pitchblende and coffinite overgrowths. The uranium isotopic composition of late pitchblende generations, the products of dissolution and reprecipitation of early phases, is 0.46‰ lighter than that of early pitchblende phases. The character of uranium isotope distribution in pitchblende aggregates is consistent with nuclear-volume-dependent isotope fractionation accompanying U(VI) reduction to U(IV) (Bigeleisen, 1996; Schauble, 2007; Stirling et al., 2007), which causes an enrichment of the U(IV)-bearing solid phase in the heavy isotope 238U. The range of 238U/235U ratios for 11 hydrothermal (high-temperature) deposits (137.703–137.821) lies well within the broader (two-fold) range of values determined for the low-temperature deposits Dybryn in Transbaikalia (Golubev et al., 2013) and Pepegoona in South Australia (Murphy et al., 2014). This can be explained by the fact that the uranium isotopic fractionation associating with U(VI) → U(IV) reduction is accompanied by isotope shifts owing to the long-term interaction of groundwater with early phases within sandstone-type deposits. At the same time, owing to the higher temperatures (by 100–300°C) of formation of hydrothermal deposits compared with sandstone-type deposits, nuclear-volume-dependent uranium isotope fractionation decreases by more than a factor of 2 (Bopp et al., 2009).

The isotopic (U-Pb, 238U-235U, 234U-238U) and chemical study of whole-rock samples and finegrained fractions of rocks in a vertical section of the terrigenous sequence at the Dybryn uranium deposit in the Khiagda ore field shows that a wide U-Pb isotopic age range (26.9-6.5 Ma) is caused by oxidation and disturbance of the U-Pb isotopic system in combination with protracted uranium ore deposition. The oxidation of rocks resulted in the loss of uranium relative to lead and eventually to an overestimated 206Pb/238U age at sites with a low U content. The 238U/235U ratios in the studied samples are within the range of 137.74–137.88. Samples with a high uranium content are characterized by a decreasing 238U/235U ratio with a decrease in 207Pb/235U and 206Pb/238U ages. A nonequilibrium 234U/238U ratio in most studied samples furnishes evidence for young (

Quartz-tourmaline lenses, around which host granite is impregnated by uraninite, have been found among porphyritic granite with large phenocrysts of the Urtui pluton in the Ttansbaikal krai framing the Strel’tsovka volcano-tectonic structure. Two generations of tourmaline are distinguished. Most individual crystals belong to the first generation attributed to “fluor-schorl”; tourmaline-II attributed to schorl occurs as thin rims overgrowing tourmaline-I. The major type of cation isomorphic substitution in both tourmalines is Fe2+ → Mg. The Fe3+/Fetot value and Li content in the average sample are 2% and 80 ppm, respectively. The high F content, comparatively high Li, low Fe3+/Fetot value, and character of cation isomorphic substitution indicate that the tourmaline relates to greisens. The combination of these features allows one to distinguish greisen-type tourmaline-bearing rocks. The impregnated uranium mineralization in granite of the Urtui pluton, one of the probable sources of uranium in economic U ore of the Strel’tsovka deposit, is suggested to be caused by greisenization and the formation of quartz-tourmaline lenses.

An isotopic geochronological study of dispersed uranium mineralization was performed in the granitic rocks of the Urtui pluton in the framework of the Strel’tsovka uranium ore field and in the Yamsky site of the Urov-Uryumkan granite-gneiss arch. Two stages of such mineralization—783 ± 26 Ma in the Urtui granitic pluton and 138.6 ± 2.3 Ma in the Yamsky site—have been established. The emplacement of granite pertaining to the Unda Complex disturbed the U-Pb isotopic system in uraninite from the Urtui granitic pluton and resulted in redeposition of uranium phase dated at 262 ± 34 Ma. The young, probably, recent process gave rise to the redistribution of radiogenic lead in the U-bearing phases developing after uraninite.

An isotopic geochronological study of Russia’s largest Strel’tsovka uranium district has been carried out. Polychronous granite generation, which determined the structure of the pre-Mesozoic basement, had important implications for the formation of volcanotectonic structural elements bearing economic uranium mineralization. The study of U-Pb, Rb-Sr, and Sm-Nd isotopic systems of whole-rock samples and minerals of granitic rocks allowed us to estimate the deportment of these systems in spatially conjugated granite-forming and hydrothermal processes differing in age and gave grounds for revising the age of granites pertaining to the Urulyungui Complex and refining the age of the Unda Complex.

U-Pb systems were examined in samples (ranging from 4 to 10 cm3 in volume) of ore material taken from along a 3.5-m profile across a zone of U mineralization exposed in an underground mine at the Strel’tsovskoe U deposit in eastern Transbaikalia. The behaviors of two isotopic U-Pb systems (238U-206Pb and 235U-207Pb) are principally different in all samples from our profile. While the individual samples are characterized by a vast scatter of their T(206Pb/238U) age values (from 112 to 717 Ma), the corresponding T(207Pb/235U) values vary much less significantly (from 127 to 142 Ma) and are generally close to the true age of the U mineralization. The main reason for the distortion of the U-Pb system is the long-lasting (for tens of million years) migration of intermediate decay products in the 238U-206Pb(RD238U) in the samples. This process resulted in the loss of RD238U from domains with high U concentrations and the subsequent accommodation of RD238U at sites with low U concentrations. The long-term effect of these opposite processes resulted in a deficit or excess of 206Pb as the final product of 238U decay. The loss or migration of RD238U are explained by the occurrence of pitchblende in association with U oxides that have higher Si and OH concentrations than those in the pitchblende and a higher +6U/+4U ratio. The finely dispersed character of the mineralization and the loose or metamict texture of the material are the principal prerequisites for RD238U loss and an excess of 206Pb in adjacent domains with low U concentrations. Domains with low U contents in the zone with U mineralization serve as geochemical barriers (because of sulfides contained in them) at which long-lived RD238U(226Ra, 210Po, 210Bi, and 210Pb) were accommodated and subsequently caused an excess of 206Pb. The 235U-207Pb system remained closed because of the much briefer lifetime of the 235U decay products. This may account for the significant discrepancies between the T(206Pb/238U) and T(207Pb/235U) age values. RD238U was most probably lost via the migration of radioisotopes at the middle part and end of the 238U family (starting with 226Ra). The heavy Th, Pa, and U radioisotopes (234Th, 234Pa, 234U, and 230Th) that occur closer to the beginning of 238U decay, before 226Ra, only relatively insignificantly participated in the process. Our results show that the loss and migration of RD238U are, under certain conditions, the main (or even the only) process responsible for the distortion of the U-Pb system.

Based on the study of local volumes of minerals, including their microsampling and subsequent analysis of Pb/Pb and U/Pb isotope ratios with the classic methods of isotopic dilution and thermoionization mass spectrometry (TIMS), U-Pb and Pb-Pb isotopic datings of minerals were carried out in uranium ores from deposits in the Akitkan and Nechera-Nichatka ore districts (North Baikal region). Reliable evidence in favor of the Middle Devonian (384 ± 8 Ma) remobilization of Paleoproterozoic primary uranium concentrations and the redeposition of uranium as pitchblende 2 has been obtained for the first time for ores of the Akitkan district. The Paleoproterozoic (1832 ± 13 Ma) age of uraninite mineralization and the timing of the latest (377 ± 5 Ma) transformation of uranium ores at the Chepok deposit (Nechera-Nichatka district) are substantiated.

Isotopic analysis of hydrogen and oxygen was performed using the DeltaPlus mass spectrometer (ThermoQuest, Finnigan). Gaseous hydrogen from water samples was obtained by the decomposition of water on hot powder of metallic chrome at 800 ° C. Determination of the oxygen isotopic composition was based on the method of isotopic balance of water with ee 2 [5]. The δ D and δ 18 e values were determined accurate to 0.3 and 0.2 ‰, respectively. We used the following MAGATE reference samples: OH-1, OH-2, OH-3, and OH-4. All results presented in Figs. 1 and 2 are shown relative to the international standard V-SMOW.

Experimentally it is shown that, under irradiation in an atmosphere of non-saturated vinylidene chloride vapors, a polymeric layer is formed on the surface of oxidized titanium samples. The thickness of this layer increases with the increase of thickness of the oxide film. Such a dependence corresponds to the current understanding of the mechanism of formation and migration of the active excited centers that initiate grafted polymerization.

In this work the first samples of polymeric semi-conductors of a new structure are produced. Their electric conductivity is of the order ∼10 -2 Ohm -1 . cm -1 and it increases with temperature. Their synthesis includes a stage of radiation grafting of a matrix-type on stretched polyamide films. Conducting molecular circuits in such materials include fragments with conjugated bonds and metal clusters. The alternation of these fragments is determined by the polyamide matrix.

The available information about the mechanisms of the interaction of pesticides having different chemical structures with the lipid bilayer in cell membranes is presented. It is shown that, depending on the degree of lipophilicity, the molecular dipole moment, and certain other characteristics of the pesticide compound, its interaction with the lipid bilayer generally takes place via one of the three main mechanisms involving the incorporation of the pesticide molecules in the hydrocarbon region within the bilayer, the adsorption of these molecules in the zone of the polar membrane phospholipids, or the incorporation of the amphiphilic pesticide compounds in both the non-polar and polar regions of the membrane. The bibliography includes 109 references.

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 structure of β-Ca3 (PO4)2 is known to be similar to that of whitlockite (R3c, Z =21). The cations are distributed in five different positions, the position Ca(4) being only half occupied. The whitlockite network is stable while the filling of the Ca(4) position changes from 0 to 1. The presence of vacancies allows to provide heterovalent substitutions 3Ca2+ = 2M3+ + and Ca2+ + 0 = 2Me+ with limits of compositions Ca9M (PO4)7 and CaloMe(PO4)7 respectively. The possible cation size can be changed from 0.55 A (Fe3+) to 1.51 A (K+). In order to check these suggestions we have synthesized Ca9M(PO4)7 (M = rare earth element, Y, Bi, Fe, Al, In, Sc) compounds, The double phosphates were studied by luminescence, infrared spectroscopy and X-ray diffraction. All these compounds are isostructural to β-Ca3(PO4)2. The cell parameters gradually decrease for M = La-Ho, Y and remain constant for M = Er-Lu. This divergence can be attributed to the change of the coordination number of the rare earth element. A ...

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).