Dependence of glow discharge Si:H:Cl film morphology on diluent gas and SiCl4 partial pressure

TEM, THEED and field-assisted silver ion exchange have been employed to study the glow discharge (GD) SiHCl films deposited from SiH₄-SiCl₄ gas mixtures. The character of the THEED patterns shows that the films are rather amorphous, and that their structure does not alter with the change in the gas mixture. The honeycomb-like morphology of the films is strongly affected by the type of gas in which SiH₄ is diluted (Ar or H₂). An increase in the SiCl₄ partial pressure leads to the uniformity and to the decrease of the island dimension only for the films deposited from SiH₄(H₂)-SiCl₄. A possible correlation between the film morphology and the micropore density is proposed.     

Temperature gradients effects in low-power laser annealing of ion implantedα-Ge

The influence of temperature gradients in laser annealing of-Ge, obtained below the melting threshold, was tested by irradiating the samples with a linear fringe pattern from a pulsed ruby laser. The peak temperature reached on the specimen surface was calculated to be well below the melting threshold of the material. Temperature gradients are observed to enhance the crystallization process in the material. Spontaneous periodic structures, or ripples, having a period equal to the laser wavelength, are frequently observed in areas corresponding to minima of the fringe pattern.Gruppo Nazionale di Struttura della Materia     

Determination of triazines and dinitroanilines in waters by high-performance liquid chromatography after solid-phase extraction

A rapid and selective method for the simultaneous determination of triazines and dinitroanilines in real water matrices is suggested based on a preliminary adsorption on an RP-18 cartridge, an elution step using acetonitrile and HPLC separation with a Lichrosorb RP- Select B column and UV detection. The washing step cartridge is critical for triazines: terbutryn is eluted with quantitative recovery only after washing with an NH₃ solution. The degree of enrichment of the compounds studied has been determined: triazine recoveries are quantitative, while dinitroaniline recoveries are between 66% and 78% at the lowest fortification level. The detection limits for the ten herbicides are in the range 0.03-0.1 μg/l. The analysis time is 2 h.     

HPLC determination of catabolic amines in silage using their dansyl derivatives and an electrochemical detector

Summary The use of the electrochemical detector (EC) in the high performance liquid chromatography (HPLC) of dansyl derivatives of biogenic amines is reported. Isocratic and gradient elution patterns of synthetic mixtures of putrescine, cadaverine, 1,6-diaminohexane, tryptamine, histamine, tyramine, spermine and spermidine on a reversed phase column are shown. Hydrodynamic voltammograms of standard compounds are presented. The detection limits of the EC are compared with those of ultraviolet and spectrofluorimetric detectors. A chromatographic profile of amines from the proteolytic catabolism of maize silage byClostridia is shown.Presented at the 17th International Symposium on Chromatography, September 25–30, 1988, Vienna, Austria.     

Ueber die gerichtliche Chemie des Sulfonals

Ohne Zusammenfassung     

Pointwise estimates for solutions to the porous medium equation with measure as a forcing term

For porous media equations with a Radon measure on the right-hand side, we derive pointwise estimates for solutions via the Riesz potentials.     

Local probabilities for random walks conditioned to stay positive

Let S ₀ = 0, {S _n , n ≥ 1} be a random walk generated by a sequence of i.i.d. random variables X ₁, X ₂, . . . and let $\tau ^{-}={\rm min} \{ n \geq 1:S_{n}\leq 0 \}$ and $\tau ^{+}={\rm min}\{n\geq1:S_{n} > 0\} $ . Assuming that the distribution of X ₁ belongs to the domain of attraction of an α-stable law we study the asymptotic behavior, as ${n\rightarrow \infty }$ , of the local probabilities ${\bf P}{(\tau ^{\pm }=n)}$ and prove the Gnedenko and Stone type conditional local limit theorems for the probabilities ${\bf P}{(S_{n} \in [x,x+\Delta )|\tau^{-} > n)}$ with fixed Δ and ${x=x(n)\in (0,\infty )}$ .     

Interatomic decay of inner-valence-excited states in clusters

In an isolated atom, excitation of an inner valence electron above the outer valence subshell leads to creation of an autoionizing state. Recently, it has been demonstrated experimentally that in a cluster, the inner-valence-excited states can decay also by an interatomic mechanism which has been called resonant interatomic Coulombic decay (RICD). Here we show that RICD is indeed the leading but not the only possible interatomic decay mode of the inner-valence excitations in clusters. Using Ne (2s-->3p) excitation in MgNe cluster as an example, we explore the possible decay mechanisms and draw conclusions on their relative importance and on the nature of the corresponding decay products.     

The chain rule as a functional equation

We consider operators T from C¹(R) to C(R) satisfying the “chain rule”