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101.
G. Vitali M. Marinelli U. Zammit F. Scudieri 《Applied Physics A: Materials Science & Processing》1984,35(4):233-239
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 相似文献
102.
Determination of triazines and dinitroanilines in waters by high-performance liquid chromatography after solid-phase extraction 总被引:2,自引:0,他引:2
Patrizia Vitali Emanuela Venturini Cristina Bonora Rino Calori Raffaella Raffaelli 《Journal of chromatography. A》1994,660(1-2):219-222
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. 相似文献
103.
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. 相似文献
104.
C. Kippenberger Unger Wefers-Bettink Strobel und D. Vitali 《Fresenius' Journal of Analytical Chemistry》1902,41(1):73-75
Ohne Zusammenfassung 相似文献
105.
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107.
For porous media equations with a Radon measure on the right-hand side, we derive pointwise estimates for solutions via the Riesz potentials. 相似文献
108.
109.
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 ${x=x(n)\in (0,\infty )}$ . 相似文献
110.
Vasylyev MV Wachtel EJ Popovitz-Biro R Neumann R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(13):3507-3514
An organic-inorganic hybrid material, TPPhA-Ti, was constructed by non-hydrolytic condensation of a dendritic tetrakis-1,3,5,7-(4-phosphonatophenyl)adamantane precursor and titanium(IV) isopropoxide. One preparative pathway yielded insoluble materials with a Ti/P ratio of approximately 1 which was confirmed by a combination of FT-IR, TGA, and EDS measurements. N2 sorption experiments showed that TPPhA-Ti is a porous solid (micropores approximately 13 A; mesopores approximately 38 A) with a high surface area, approximately 550 m2 g(-1). The structure and morphology of the TPPhA-Ti as investigated by transmission and scanning electron microscopy showed a layered-type material. Additional X-ray diffraction data suggest a paracrystalline material; an optimization of possible molecular arrangements of TPPhA-Ti was simulated that was in agreement with the experimental data. A second preparative pathway yielded a Ti oxide-phosphonate with a Ti/P ratio of approximately 3.4. Both TEM and SEM revealed that hollow nanospheres were formed with diameters of approximately 180-300 nm. 相似文献