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71.
Lj. Simić L. Rak O. Adamović M. Jurić Tsai Chü C. O. Kim J. Lory B. Willot D. Schune C. Meton R. Kaiser I. Otterlund E. Stenlund H. Areti C. J. Hébert J. Hébert G. Baumann R. Devienne R. Schmidt L. Bravo R. Niembro A. Ruiz E. Villar J. M. Bolta M. A. Sanchis 《Zeitschrift fur Physik C Particles and Fields》1979,2(4):291-294
We present a study of two-particle correlations in proton-emulsion nucleus reactions at 400 GeV. In particular the correlations at different nuclear excitations and different rapidity regions are treated. Positive correlations, depending on nuclear excitation, are observed in the rapidity region η<1.5. 相似文献
72.
Copula convergence theorems for tail events 总被引:3,自引:0,他引:3
Tail dependence is studied from a distributional point of view by means of appropriate copulae. We derive similar results to the famous Pickands–Balkema–de Haan Theorem of Extreme Value Theory. Under regularity conditions, it is shown that the Clayton copula plays among the family of archimedean copulae the role of the generalized Pareto distribution. The practical usefulness of the results is illustrated in the analysis of stock market data. 相似文献
73.
Dr. Michael Georg Hoesl M. Sc. Stefan Oehm Dr. Patrick Durkin Dr. Elise Darmon Dr. Lauri Peil Dr. Hans‐Rudolf Aerni Prof. Dr. Juri Rappsilber Prof. Dr. Jesse Rinehart Prof. Dr. David Leach Prof. Dr. Dieter Söll Prof. Dr. Nediljko Budisa 《Angewandte Chemie (International ed. in English)》2015,54(34):9726-9726
74.
Albena K. Detcheva Svilen E. Mitsiev Paunka S. Vassileva Juri H. Jordanov Metody G. Karadjov Elisaveta Ivanova 《Chemical Papers》2015,69(5):650-654
The contents of Cl, Ca, K, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba and Pb in raw coal fly ash from five Bulgarian power plants were determined by total reflection X-ray fluorescence (TXRF), using gallium as the internal standard. The samples were analysed as in slurry form in Triton? X-114. The experimental parameters, such as grain size, concentrations of fly ash slurry and excitation time were optimised. For validation of the method, the certified reference material BCR-176R fly ash was used. The precision of the results obtained is characterised by a relative standard deviation of approximately 10%. The resulting data confirm the suitability of TXRF for the simultaneous determination of major, minor and trace elements in coal fly ash samples. Further advantages provided by TXRF are easy sample preparation (no sample dissolution) and the small sample amount required for analysis. 相似文献
75.
Alexander Kremsmair Juri Skotnitzki Prof. Dr. Paul Knochel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(52):11971-11973
Chiral secondary alkylcopper reagents were prepared from the corresponding alkyl iodides with retention of configuration by an I/Li-exchange using tBuLi (−100 °C, 1 min) followed by a transmetalation with CuBr ⋅ P(OEt)3 (−100 °C, 20 s). These stereodefined secondary alkylcoppers underwent stereoretentive cross-couplings with several 3-iodo or 3-bromo unsaturated carbonyl derivatives leading to the corresponding γ-methylated Michael acceptors in good yields and with high diastereoselectivities (dr up to 96:4). The method was extended to enantiomerically enriched alkylcoppers, providing optically enriched advanced natural product intermediates with up to 90 % ee. 相似文献
76.
Juri Ugolotti 《Journal of organometallic chemistry》2011,696(6):1184-1188
Treatment of R2Si(CC-SiMe3)2 [1a (Me), 1b (Ph)] with HB(C6F5)2 at low temperature (253 K (a), 273 K (b)) gives the -B(C6F5)2 substituted silacyclobutene products (4a,b) under kinetic control. Upon warming to room temperature they disappear to form the thermodynamically favoured isomeric silole derivatives (2a,b). Similar treatment of Me2Si(CC-R1)2 [5a (R1 = Ph), 5b (R1 = tert-butyl) with HB(C6F5)2 at room temperature gave the stable -B(C6F5)2 substituted silacyclobutene derivatives 6 and 7, respectively. Subsequent photolysis resulted in a Z- to E-isomerization of the substituted exocyclic CC double bonds in these products. The silacyclobutene derivative E-6 was characterized by an X-ray crystal structure analysis. 相似文献
77.
Karin Kipper Kaili Anier Ivo Leito Juri Karjagin Kersti Oselin Koit Herodes 《Chromatographia》2009,70(9-10):1423-1427
A rapid and sensitive LC-UV method was developed and validated for the determination of meropenem, in human plasma and urine. Meropenem retention time was 4.8 min. Method development was based on comparative analysis of different extraction methods published as well as careful study of meropenem stability in biological samples under different conditions. Best results in plasma sample preparation were obtained from protein precipitation with methanol. LOQ was 0.1 µg mL?1 for plasma and 1 µg mL?1 for urine samples. Meropenem in plasma has low stability at room temperature (<20% of original content after 12 h), but had acceptable stability when the whole analysis procedure was designed to minimize the exposure of meropenem-containing samples and solutions to temperatures higher than 4 °C. The developed method was applied to a human pharmacokinetic study in patients with acute peritonitis. 相似文献
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