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71.
The salts [(eta-C(5)Me(5))Ru(NO)(bipy)][OTf](2) (1[OTf](2)) and [(eta-C(5)Me(5))Ru(NO)(dppz)][OTf](2) (2[OTf](2)) are obtained from the treatment of (eta-C(5)Me(5))Ru(NO)(OTf)(2) with 2,2'-bipyridine (bipy) or dipyrido[3,2-a:2',3'-c]phenazine (dppz) (OTf = OSO(2)CF(3)). X-ray data for 1[OTf](2): monoclinic space group P2(1)/c, a = 11.553 (4) ?, b = 16.517 (5) ?, c = 14.719 (4) ?, beta = 94.01 (2) degrees, V = 2802 (2) ?(3), Z = 4, R1 = 0.0698. X-ray data for 2[OTf](2): monoclinic space group P2(1)/c, a = 8.911 (2) ?, b = 30.516 (5) ?, c = 24.622 (4) ?, beta = 99.02 (1) degrees, V = 6613 (2) ?(3), Z = 8, R1 = 0.0789. Both 1[OTf](2) and 2[OTf](2) are soluble in water where they exhibit irreversible electrochemical oxidation and reduction. A fluorescence-monitored titration of a DNA solution containing 2[OTf](2) with ethidium bromide provides evidence that 2(2+) intercalates into DNA with a binding constant greater than 10(6) M(-)(1). DNA cleavage occurs when the DNA solutions containing 2[OTf](2) are photolyzed or treated with H(2)O(2) or K(2)S(2)O(8). 相似文献
72.
The simultaneous determination of carbon and sulphur in the ppb-range (or in rag-samples in the low ppm-range) in high purity metals is described. The combustion of the sample (1–1000 mg) is performed in purest oxygen without additives by means of induction heating (6 MHz, 3 kW). The combustion products CO2 and SO2, after separation in a gaschromatographic column, are detected using a relative conductometric method. The limits of detection for the determination of carbon and sulphur in vanadium, niobium, tantalum, tungsten, molybdenum, noble metals, copper, aluminium, iron, chromium are 5 ng. With amounts of 100 ng the relative standard deviations of ±5% for carbon and ±6% for sulphur were found. Problems in lowering the blank values (e.g. sample preparation, gas purification, combustion), in absorption of CO2 and SO2, and in conductivity measurement are discussed in detail and some calibration methods are compared. 相似文献
73.
74.
D. Elsner B. Bantes O. Bartholomy D. E. Bayadilov R. Beck Y. A. Beloglazov R. Castelijns V. Crede A. Ehmanns K. Essig R. Ewald I. Fabry F. Frommberger K. Fornet-Ponse M. Fuchs C. Funke A. B. Gridnev E. Gutz W. Hillert S. H?ffgen P. Hoffmeister I. Horn I. Jaegle J. Junkersfeld H. Kalinowsky Frank Klein Friedrich Klein E. Klempt M. Konrad M. Kotulla B. Krusche H. L?hner I. V. Lopatin J. Lotz S. Lugert D. Menze T. Mertens J. G. Messchendorp V. Metag C. Morales M. Nanova D. V. Novinski R. Novotny M. Ostrick L. M. Pant H. van Pee M. Pfeiffer A. V. Sarantsev C. Schmidt H. Schmieden B. Schoch S. Shende A. Süle V. V. Sumachev T. Szczepanek U. Thoma D. Trnka D. Walther C. Weinheimer C. Wendel 《The European Physical Journal A - Hadrons and Nuclei》2009,39(3):373-381
At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond
crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the
crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement
between experiment and expectations on the basis of the experimental conditions is obtained. Polarisation degrees of % are typically achieved at half of the primary electron energy. The determination of is confirmed by measuring the beam asymmetry, , in photoproduction and by a comparison of the results to independent measurements using laser backscattering. 相似文献
75.
Bassalleck B Berdoz A Bradtke C Bröders R Bunker B Dennert H Dutz H Eilerts S Eyrich W Fields D Fischer H Franklin G Franz J Gehring R Geyer R Goertz S Harmsen J Hauffe J Heinsius FH Hertzog D Johansson T Jones T Khaustov P Kilian K Kingsberry P Kriegler E Lowe J Meier A Metzger A Meyer CA Meyer W Moosburger M Oelert W Paschke KD Plückthun M Pomp S Quinn B Radtke E Reicherz G Röhrich K Sachs K Schmitt H Schoch B Sefzick T Stinzing F Stotzer R Tayloe R Wirth S 《Physical review letters》2002,89(21):212302
Spin-transfer observables for p p-->Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables Dnn and Knn (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of Dnn and Knn presented here are found to be in disagreement with predictions from these models. 相似文献
76.
77.
Dutz H Helbing K Krimmer J Speckner T Zeitler G Ahrens J Altieri S Annand JR Anton G Arends HJ Beck R Bock A Bradtke C Braghieri A v Drachenfels W Frommberger F Godo M Goertz S Grabmayr P Hasegawa S Hansen K Harmsen J Heid E Hillert W Holvoet H Horikawa N Iwata T Hoorebeke LV D'Hose N Jennewein P Kiel B Klein F Kondratiev R Lang M Lannoy B Leukel R Lisin V Menze D Meyer W Michel T Naumann J Panzeri A Pedroni P Pinelli T Preobrajenski I Radtke E Reicherz G Rohlof C Rostomyan T Sauer M Schoch B 《Physical review letters》2004,93(3):032003
For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule. 相似文献
78.
A. Schoch 《International Journal of Theoretical Physics》1968,1(1):107-113
It is shown that the simplicity of the C* -algebra of quasilooal observables of a Haag field caa be deduced from a postulate which seems to be plausible from a physical point of view.Work supported by the Swiss National Science Foundation. 相似文献
79.
Ion irradiation with Xe+ has been utilized to produce electrical conductivity in PMMA, as measured using a four-point in-line probe. Incident ion beam energy and current density have been varied to investigate their effect on electrical conductivity and optical absorbance of the samples after irradiation. Results support the premise that selection of beam parameters that maximize the ratio of energy transfer-producing displacements to energy transfer-producing ionization maximizes the ratio of induced conductivity to induced absorbance in the irradiated samples. Conductivity versus ion dose has also been shown to be well estimated using a damage trial model. © 1994 John Wiley & Sons, Inc. 相似文献
80.
Chemistry and kinetics of chemical vapor deposition of pyrolytic carbon from ethanol 总被引:2,自引:0,他引:2
A. Li S. Zhang B. Reznik S. Lichtenberg G. Schoch O. Deutschmann 《Proceedings of the Combustion Institute》2011,33(2):1843-1850
Synthesis of pyrolytic carbon as a matrix for carbon fiber reinforced carbon composites by chemical vapor infiltration (CVI) is studied experimentally and numerically using the oxygen-containing precursor ethanol. The effects of residence time on microstructure and deposition rate of pyrolytic carbon are investigated. A short residence time is found to favor the formation of high-textured pyrolytic carbon. The evolutions of microstructure and deposition rate of pyrolytic carbon are compared with those of carbon deposited from methane. Compared to methane, ethanol exhibits a much higher deposition rate of pyrolytic carbon with similar microstructures. Pyrolysis of ethanol is modeled using a two-dimensional flow model coupled with a detailed gas-phase reaction mechanism involving 261 species taking part in 1177 reversible reactions. Reaction rate analysis reveals that C3-hydrocarbons are the most important intermediate species contributing to the maturation of gas-phase composition. A comparison of the kinetic predictions with equilibrium calculations demonstrates that the CVD reactor applied is operated far away from equilibrium. 相似文献