High-efficiency deflection of high-energy protons through axial channeling in a bent crystal

Beam deflection due to axial channeling in a silicon crystal bent along the 111 axis was observed with 400 GeV/c protons at the CERN Super Proton Synchrotron. The condition for doughnut scattering of protons by the atomic strings of the crystal was attained. Such a condition allowed one to observe a beam deflection of 50 murad with about 30% efficiency. The contribution of hyperchanneled states of protons to the observed beam deflection was less than 2% according to simulation results.     

Employment of differential pulse polarography and adsorptive voltammetry for the determination of some sulfonamides

Reduction of sulfonamides in mineral acids was investigated using fast scan differential-pulse polarography (FSDPP). The optimal medium for sulfadimidin, sulfamethoxydin and sulfamethoxypyridazin is 0.01–0.02M HCl, while for phthalazol it is 1M HCl and the latter compound can be selectively determined in the presence of other sulfonamides. Adsorptive properties on the Hg-electrode were analytically used in the case of sulfamethoxypyridazin and phthalazol. Relative standard deviation of all determinations did not exceed 8%.     

Photon-electron scattering taking vacuum energy into account

We deal with photon-electron scattering between the two uncharged conducting parallel plates. The electromagnetic vacuum field between the two plates is defined by the configuration of space and also interacts with the electrons. We first deal with the relevant operators for the electron and photon fields and with the Feynman propagator. We compute theS-matrix for photon-electron scattering, taking into account the influence of the vacuum field. The computed photon-electron scattering cross section also manifests the influence of the vacuum field. We give an example for low-energy scattering of the influence of the vacuum field upon the scattering cross section.     

An interlaboratory characterization (certification) campaign to establish the elemental composition of a new series of agricultural/food reference materials

Summary Ten new Agricultural/Food Reference Materials (RM) have been characterized with respect to their elemental compositions in an extensive interlaboratory characterization (certification) campaign. The philosophy applied to determine best estimate and informational concentration values was the expert analyst-independent method approach. Chemical analyses were conducted in two initiating laboratories and by analysts in 73 cooperating laboratories applying 13 major classes of independently different analytical methods; approximately 13,000 results were obtained for a large number of nutritionally, toxicologically and environmentally pertinent elements. Results were assessed in depth using technical judgment and statistical criteria. A total of 213 best estimate values, with associated uncertainties for a single future observation, and 65 informational values were obtained. Concentrations were measured for 34 elements in 10 materials which represent a wide range of matrices and elemental contents and significantly augment the world repertoire of reference materials.Contribution no. 92–214 from Centre for Land and Biological Resources Research     

Darstellung und Eigenschaften zweier isomerer Formen des Dichloro-bis[triphenylphosphinoxid—Kupfer(II)]-Komplexes

Cu(OPph ₃)₂Cl₂ exists in yellow - and orange -isomeric forms. -Cu(OPph ₃)₂Cl₂ was prepared by thermal decomposition of Cu(OPph ₃)₄Cl₂·2 H₂O and by reaction of CuCl₂ with OPph ₃ in acetone—ethanol mixture at higher temperature. The results of magnetic measurements, electronic andESR spectra show that the structure of -isomer differs from the known structure of the -isomer by a different degree of distortion of the coordination tetrahedron. -Cu(OPph ₃)₂Cl₂ is thermodynamically more stable then -Cu(OPph ₃)₂Cl₂.

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Mit 3 Abbildungen     

The application of the růžička-type iodide-selective electrode for the determination of cyanide in alcoholic drinks

The Selectrode withiodide Selectrode powder is used successfully to determine cyanide in pure solutions in alcoholis drinks at 0.2–2 mg l^?1 levels. The calibration slope was ca. 63.5 mV/decade concentration in pure solutios but changed in alcoholic solution. A double standard addition method was needed for free cyanide determinations in alcoholic drinks.     

Dissociation-association sorption on ion exchangers. I. Experimental study of dependence of equilibrium function of acidity in ion exchanger on activity of hydrogen ions in aqueous phase

Equilibrium coloring of crystal violet, methyl violet, and dimethyl yellow sorbed on ion exchanger Dowex-50-WX4 was studied by a spectrophotometric method as a function of the pH of the aqueous phase. From the data obtained, the function of acidity in a ion exchanger was calculated corresponding to individual equilibriums of the exchange reaction. A simple relationship between H?_0′ in a ion exchanger and the pH of the aqueous phase was found.     

ОБ УРАВНЕНИИ БАБА ДЛЯ ЧАСТИЦЫ С НАИБОЛЬШИМ СПИНОМ 3/2

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A Note to Bhabha's equation for a particle with maximum Spin 3/2