Untersuchungen von verdampfungs- und plasmaprozessen in der graphitrohrküvette zur optimierung von AA-bestimmungen—II. Molekülabsorptions-spektrometrische und atomabsorptions-spektrometrische untersuchungen an wäßrigen Lösungen und organischen extrakten des galliums und indiums

The authors compared the sensitivities achieved in the determination of Ga and In by AAS with electrothermal atomization in graphite cuvettes in dependence on the solvent, i.e. some acids and organic extracts. The best sensitivity was found in an HNO₃ environment. Signal depressions were observed especially in the presence of halides and with solvents containing halogens. The results of the investigations showed that the principal cause of the depressions is the formation of stable molecules of the type MX (M = Ga or In; X = Cl or Br) in the gaseous state. A second cause is the evaporation. The temperature, in particular that prevailing during the ashing step affects the X-concentration in the gaseous state because of thermal hydrolysis of unstable salts or evaporation of the organic solvents.     

Anomalous transmission of swift electrons in thick crystals

A large penetration of swift electrons along the lattice crystallographic axes was observed. The center transmission peak of 2 MeV electrons along the 〈100〉 axis in 110 μm NaCl shows a narrow dip of width at half-minimum (0.2 ± 0.05). The half-width of the maximum base (0.7 ± 0.1) is in agreement with the classical mechanical calculation.     

A New Shuffle Convolution for Multiple Zeta Values

Recently, interest in shuffle algebra has been renewed due to their connections with multiple zeta values. In this paper, we prove a new shuffle convolution that implies a reduction formula for the multiple zeta value z({5,1}ⁿ).Research partially supported by a grant from the Number Theory Foundation.     

Upper and lower bounds of temporal and spatial decays for the Navier-Stokes equations

We obtain the lower bounds of the temporal-spatial decays for weak solutions of the Navier-Stokes equations

     

Einflu? des Reaktionsmediums auf die Kinetik und den Mechanismus der kationischen Polymerisation und Copolymerisation der cyclischen ?ther

Ohne Zusammenfassung     

Theoretische Untersuchung des Prozesses der Bildung von Kondensationspolymeren — Polvamidsäuren

Ohne Zusammenfassung     

Untersuchung der enzymatisch aktiven Trypsin-fragmente

Ohne Zusammenfassung     

Uniform approximation: The non-locally convex case

IfS is a compact Hausdorff space of finite covering dimension and (E, τ) is a real or complex topological vector space (not necessarily locally convex), we prove a Weierstrass-Stone theorem for subsets ofC(S;E), the space of all continuous functions fromS intoE, equipped with the topology of uniform convergence overS.     

Novel Zn1-xMnxSe (x = 0.1-0.4) one-dimensional nanostructures: nanowires, zigzagged nanobelts, and toothed nanosaws

Novel Zn1-xMnxSe one-dimensional nanostructures-straight nanowires (x = 0.1 and 0.3), zigzagged nanobelts (x = 0.4), and toothed nanosaws (x = 0.4)-were synthesized using the chemical vapor deposition method. They all consisted of single-crystalline wurtzite ZnSe crystals, irrespective of the Mn content. In particular, the nanosaws have a unique structure in which double-sided teeth are rooted in the nanowire core and bent so as to align as two parallel rows. The long axis is parallel to the [010] direction, and all of the teeth have the [0001] growth direction. The X-ray diffraction pattern confirms the formation of wurtzite ZnSe crystal and the decrease of the lattice constant owing to Mn doping. The Mn2+ emission at 2.1 eV (appeared below 100 K), originating from the d-d (4T1 --> 6A1) transition, proves the effective substitution of Mn2+ ions at the tetrahedral coordinate sites.