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901.
A novel layered K(4)Ag(2)Sn(3)S(9) x 2KOH was synthesized solvothermally. A mixture of ethanol and HSCH(2)CH(SH)CH(2)OH was used for the synthesis. The HSCH(2)CH(SH)CH(2)OH plays an important role and appears to serve as a mineralizer for the solvothermal reaction. A layer comprises Sn(3)S(9)(6)(-) clusters linked by Ag(+) ions and possesses two types of 1D channels in which potassium ions are located. The compound crystallizes in the monoclinic P2(1)/m space group [a = 7.8071(2) A, b = 27.3508(1) A, c = 10.5008(2) A, alpha = 90 degrees, beta = 103.874(1) degrees, gamma = 90 degrees, Z = 4]. Its crystal structure, composition analysis, and IR are presented. 相似文献
902.
Cai H Chen T Wang X Schultz AJ Koetzle TF Xue Z 《Chemical communications (Cambridge, England)》2002,(3):230-231
Reactions of Ta(NMe2)5 with D2SiR'Ph (R' = Me, Ph) were found to give a dideuteride eta 2-imine complex (Me2N)3Ta(mu-D)2(mu-N-eta 2-N,C-CH2NMe)Ta(NMe2)3(1-d2) through C-H activation of an amide ligand via beta-H abstraction, and the structure of 1 was confirmed by single crystal neutron and X-ray diffraction. 相似文献
903.
The Mössbauer quadrupole interaction ΔEQ of the Fe2+ ion has been measured with 2% at. 57Fe in ZnSiF6·6H2O, between 1.3 and 20°K. The sign of ΔEQ (< 0) has been determined by using a single crystal absorber. These results are interpreted in terms of a trigonal crystal field potential that splits the Fe2+ orbitals into a ground state singlet and a first excited doublet whose distance is much smaller than that reported for FeSiF6·6H2O, in reasonable agreement with previous EPR measurements. 相似文献
904.
Acid-catalysed reactions of tri-O-acetyl-D-glucal with benzotriazole, 5,6-dimethylbenzotriazole, 5,6-dichlorobenzotriazole and 6-chloropurine have been found to give anomeric mixtures of the corresponding 2′,3′-unsaturated N-glycosyl derivatives with the α-anomers preponderating. When tri-O-acetyl-D-galactal was used the 3′,4′,6′-tri-O-acetyl-α- and β-D-lyxo-hexopyranosyl nucleoside analogs were obtained. The conformation and anomeric configuration of all the N-glycosyl compounds obtained were assigned by NMR studies. 相似文献
905.
A new route has been developed for the micro-determination of227Ac in geological materials by neutron activation. The method is based on intense neutron irradiation of the analysed samples followed by separation and α-spectrometric determination of228Th, the β-decay product of the 6.1 hrs228Ac isotope formed. Two alternatives are considered for analysis related to the origin of the analysed matrix. The high sensitivity of the method is documented by the determination of 10?17 g227Ac/g sample. The method is successfully applied for age determination of five uranium containing materials and old uranium glass from Bohemia, CSSR. 相似文献
906.
The elements are separated from iron by solvent-extraction. Cr, V and Mn are separated by ion-exchange chromatography with a strong acidic cation-exchanger. The elements are determined by 14 MeV-neutron activation analysis using γ-spectroscopy. The method is suitable for a concentration range of 0.05 to 5%. 相似文献
907.
Z. F. Chai Q. F. Qian X. Q. Feng P. Q. Zhang N. Q. Liu W. Y. Feng M. X. Kuang H. Y. Wang Y. Z. Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(1):153-156
The occupational health impact of atmospheric pollution on exposed workers at one iron and steel complex was studied by instrumental neutron activation analysis of workers' hair samples and medical examination. The experimental results indicate that there is a positive correlation between the high inhalation amounts of iron and other trace elements by the exposed workers and the symptom of their high blood pressure and hypoglycemia, which implies that the atmospheric environment polluted by iron and steel industry has an adverse health impact on the exposed workers. The measures to relieve and abate the occupational diseases caused by air-borne particulate matter should be taken 相似文献
908.
S.M. F. Cozzolino 《Journal of Radioanalytical and Nuclear Chemistry》2001,249(1):15-19
A study was made in diets offered to a group of pre-school children,whose mean age was 67 months and remained the whole day in three day carecenters from Juiz de Fora, M.G., Brazil. For sampling, the duplicate portiontechnique was used, and the diets were collected and analyzed separately eachday in the 3 nurseries. Instrumental neutron activation analysis was appliedto the determination of 16 elements. The daily dietary intake values werecompared to the RDA (children 4–6 years old). Based on this reference,Ca, Fe, Se and Zn were found to be deficient, Mg and Mn were comparable tothe RDA and the Cl and Na concentrations were higher compared to their RDA.For the other elements measured, there are no RDA's for children. 相似文献
909.
Nielsen MB Moonen NN Boudon C Gisselbrecht JP Seiler P Gross M Diederich F 《Chemical communications (Cambridge, England)》2001,(18):1848-1849
Novel extended tetrathiafulvalenes (TTFs) with hexa-2,4-diyne-1,6-diylidene spacers between the two 1,3-dithiole rings and laterally appended alkynyl moieties for one- and two-dimensional scaffolding were synthesised and investigated for their electronic properties. 相似文献
910.
A. S. Romakhin F. M. Palyutin Yu. A. Ignat'ev E. V. Nikitin Yu. M. Kargin I. A. Litvinov V. A. Naumov 《Russian Chemical Bulletin》1990,39(3):585-589
The electrochemical oxidation of hexaethyl triamidophosphite in the absence of nucleophiles specially introduced into the electrolyte was studied by anodic voltamperometry and preparative electrolysis. The reversible one-electron oxidation of the triamidophosphite molecule gives an unstable radical-cation, which reacts with a molecule of the starting compound to give a dimeric radical-cation, whose subsequent oxidation leads to dodecaethylhexaamidobisphosphonium diperchlorate. This product is the first example of an acyclic, doubly charged bisphosphonium cation with a
. The crystal structure of this compound was obtained by x-ray diffraction structure analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 664–669, March, 1990. 相似文献