Magmatism and deformation times of the Xidatan rock series,East Kunlun Mountains

The Xidatan rock series consist of mylonite, gneiss and granite. The U-Pb age shows that the granite was formed at 206 Ma, and the⁴⁰Ar/³⁹Ar ages of the biotite display that the mylonite was formed at 145 Ma when the Xidatan ductile shearzone occurred. At about 110—100 Ma, the Xidatan Fault reactivated again. As a result, the biotite and muscovite of Xidatan rock series opened their argon isotope system.     

Magmatism and deformation times of the Xidatan rock series, East Kunlun Mountains

The Xidatan rock series consist of mylonite, gneiss and granite. The U-Pb age showsthat the granite was formed at 206 Ma, and the ~(40)Ar/~(39)Ar ages of the biotite display that the my-lonite was formed at 145 Ma when the Xidatan ductile shear zone occurred. At about 110-100 Mathe Xidatan Fault reactivated again. As a result, the biotite and muscovite of Xidatan rock seriesopened their argon isotope system.     

Comparative study on the antioxidant activities of extracts of Coreopsis tinctoria flowering tops from Kunlun Mountains,Xinjiang, north-western China

Coreopsis tinctoria flowering tops (CTFs) from the Kunlun Mountains in Xinjing (north-western China) have been used for tea production for about a century. This study aims to assess the antioxidant activities and total phenolic, flavonoid and proanthocyanidin contents of various solvent extracts of CTF. CTF was extracted using n-hexane, chloroform, ethyl acetate, n-butanol, 75% aqueous ethanol (AEE) and water. The antioxidant activities of the CTF extracts were investigated through DPPH, ABTS, ^*OH, ^*O₂^? , total antioxidant capacity and reducing power assays. The results showed that n-butanol extract showed the highest contents of total phenols and flavonoids, with DPPH, ABTS and ^*OH radical-scavenging activities with IC₅₀ values of 134, 90.72 and 13.8 μg mL^? 1, respectively. The AEE demonstrated the strongest DPPH and ABTS radical-scavenging activities, with IC₅₀ values of 103 and 75.16 μg mL^? 1, respectively. Given its high antioxidant effect, CTF is a good source of natural antioxidants or functional food materials.     

Trace element geochemistry of magmatic rock series of converging and diverging plate boundaries

The new results and developments of trace element geochemistry of magmatic processes are discussed. The interest and limits of neutron activation analysis for studies of trace element distributions in magnetic rocks are shown.     

Interlaboratory comoparison of analytical methods for the determination of natural series uranium and thorium isotopes in rock samples

Results are repoerted for²³⁸U,²³⁴U,²³²Th, and²³⁰Th determinations in 19 rock samples from a uranium mine, performed independently, byb three different laboratories. Uranium and thorium isotopoic activities were determkined by alpha spectrometry, after different pre-concentration and counting sample preparation techniques., Additionally, total concentrations of uranium were determined by fluorimetry and gamma spectreometry. the folloing conclusions could be drawn from this intercomparison test: (1) The results for²³⁸U specific activity agreed with the amjority of results within 10%. Lincar correlation coefficients between the three data sets were 0.999. However, for a few samples of much higher uranium concentrations, large deviations were observed, indicating problems of, sample heterogencity. (2) For the²³⁴U/²³⁸U activity ratio data, a still closer agreement was obtained (5%), as computation of the activity ratios did not, require information on the yield of the used tracer spike (²³²U). (3) The results for²³²Th specific activities and²³⁰Th/²³⁴U activity ratios showed larger deviastions between the three laboratories (typically up to 15%, in some cases still ore). Different Th-isotopes (²²⁸Th,²³⁴Th and²²⁹Th) have been used as yield tracers. The data indicates, however, that the observed deviations are not simply a consequence of a systematic difference in the calibration of the different spikes, but, probably cased by other errors such as incomplete sample dissolution, sample heterogencity, tec. The limitations of alpha spectrometry will be discussed and an application of the developed methods shown.     

Ab initio calculations of electrostatic potentials and deformation densities for a series of choline ester model systems

Ab initio LCAO-MO-SCF calculations using a double zeta basis set have been performed for the methyl esters of acetic acid, carbamic acid, methylcarbonic acid, and trifluoracetic acid, in order to model the corresponding choline esters. The systems have been compared by means of population analyses, electron density differences, electrostatic potentials and potential differences. The significance of the electrostatic potential in connection with crystal structure and packing has been studied. The differences in the proton affinity of the compounds have been correlated to differences in the potentials.     

Ketones of the 1, 4-benzodioxane series

New amino ketones and amino alcohols of the 1, 4-benzodioxane series, of pharmacological interest, are synthesized.For Part VII see [1].     

Amino acid compositions of lavender,rock rose,and rosemary

Pyatiagorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 839–840, November–December, 1990.     

The Chichibabin reaction in the Aminopyridine,azaindole, and azaindoline series

2-Aminopyridine, unlike the 3- and 4-isomers, is animated by sodium amide with the formation of 2,6-diaminopyridine. Among the dimethylaminopyridines, the 3- and 4-isomers are more active in the Chichibabin reaction, while 2-dimethylaminopyridine is converted with great difficulty under the action of sodium amide into 2,6-diaminopyridine with the initial replacement of the dimethylamine residue by an amino group. Azaindoles and azaindolines do not take part in the animation reaction. In 1-phenyl-5-azaindole, under the action of sodium amide, the pyrrole ring opens with the formation of 4-anilino-3-vinylpyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1232–1239, September, 1973.     

Synthesis and some properties of thiols,sulfides, and disulfides of the sulfolane series

Sulfolanethiols, which were oxidized to 3,3-disulfolanyl disulfide and 3,3-bis(4-hydroxysulfolanyl) disulfide, were obtained by reaction of 3-sulfolene and 4-hydroxy-2-sulfolene with sodium hydrosulfide. Previously unknown cleavage of the sulfolanyl sulfides at the C-S bond of the sulfolane ring was observed during their oxidative chlorination and alkaline hydrolysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 188–191, February, 1975.     

Synthesis of primary,secondary, and tertiary alkoxy alcohols of the enyne series

Summary By reacting ethynylvinyl ethers with aldehydes, ketones and ethylene oxide, a method was developed for the synthesis of primary, secondary, and tertiary alkoxy enyne alcohols of diverse structure, the hydration of which leads to the formation of alkoxy ketols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 359–362, February, 1965     

Synthesis,structure, and discotic mesomorphism of the new series of copper carboxylates

The synthesis, structure, and mesomorphism of a new series of copper carboxylates are described. The influence of periphery of the chelate node on the appearance of discophase is studied. A stacked hexagonal structure of copper erucate is proved. The effect of restructuring of the chelate node in this compound after its isothermic exposure, causing the loss of mesomorphism is revealed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1256–1260, July, 1995.     

Synthesis,structure, and acid-base characteristics of enaminones of the barbituric acid series

Enaminones were obtained by a tricomponent condensation of barbituric acids, aniline and triethyl orthoformate. The acid-base properties, PMR, UV and IR spectra of 5-anilinomethylene- and 1,3-dimethyl-5-anilinomethylenebarbituric acids are discussed. The properties of these compounds conform with a bipolar structure, in which the positive charge is distributed over the exocyclic part of the molecule, while the negative charge is distributed on the -dicarbonyl fragment of the heterocyclic ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 952–956, July, 1988.