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91.
92.
Gy. Vankó L. Bottyán D. L. Nagy E. Szilágyi A. Vértes 《Journal of Radioanalytical and Nuclear Chemistry》2000,246(1):97-100
Nuclear inelastic resonant scattering of synchrotron radiation was applied to the study solutions of 57Fe complexes. In order to reveal different inelastic contributions solutions of two different 57Fe complexes of different molecular dimensions with solvents of substantially different viscosities were studied. We argue that the only former experiment available in the literature overestimates the role of the diffusivity in affecting the spectrum. The first direct observation of an intramolecular vibrational transition assisting the nuclear resonance absorption in a liquid is reported. 相似文献
93.
Gy?rgy G?nd?s Gy?rgy Dombi James C. Orr 《Monatshefte für Chemie / Chemical Monthly》2000,20(3):1055-1059
The synthesis of a new chiral boroxazolidine was achieved which was used to control the stereochemistry of the borane reduction of the 20-keto group of steroids. The otherwise hardly accessible 20α-(20S)-alcohol can thus be prepared in a yield of 91%. 相似文献
94.
E Mincsovics Gy Kátay P G Ott Zs Király-Véghely Á M Móricz E Tyihák 《Chromatographia》2005,62(13):s51-s56
The first results of the combination of BioArena and OPLC with flowing eluent wall technique (FEW) show an especially attractive solution of the detection of antimicrobial activity and compound isolation based on peak collection. Because of the different separation mechanisms applied for on-line FEW–OPLC isolation of red wine constituents and for further off-line OPLC investigation of fractions, the combined system yields high selectivity. 相似文献
95.
J. Schader R. Latz M. Burkhard H. J. Frischkorn D. Hofmann P. Koschar K. O. Groeneveld D. Berényi A. Kövér Gy. Szabó 《Il Nuovo Cimento D》1986,7(2):219-240
Summary Absolute double differential cross-sections for target ionization and projectile electron loss were determined in collisions
of H+, H2
+,3He+ and3He++ ions (0.4 to 2.0 Me V/u) with He and Ar gas targets at electron emission angles from 0° up to 60°. The experimental results
are qualitatively well described by plane-wave Born approximations including screening of the projectile in target ionization
and of the target atom in the case of electron loss.
Riassunto Sono state determinate le sezioni d’urto doppie differenziali assolute per la ionizzazione del bersaglio e la perdita dell’elettrone proiettile in collisioni di ioni H+, H 2 + ,3He+ e3He++ (da 0.4 a 2.0 Me V/u) con bersagli di gas He e Ar ad angoli di emissione degli elettroni da 0° a 60°. I risultati sperimentali sono qualitativamente ben descritti dalle approssimazioni di Born per onde piane che comprendono la schermatura del proiettile nella ionizzazione del bersaglio e dell’atomo bersaglio nel caso di perdita dell’elettrone.
Резюме Определяются абсолютные дважды дифференшиальные поперечные сечения для ионизации мишени и потери электровов налетающими частишами при соударениях ионов H+, H 2 + ,3He+ и3He++ (от 0.4 до 2.0 Me V/u) в случае газовых Не и Ar мишеней при углах эмиссии электронов от 0° до 60°. Экспериментальные результаты качественно хорощо описываются с помощью плоско-волнового борновского приближения, включая экранирование налетающей частицы при ионизации мишени в случае потери электрона.相似文献
96.
97.
Sampling is part of quality evaluation as well as of the analysis. Probabilistic and non-probabilistic sampling methods are discussed, with examples of the severe financial consequences of incorrect sampling procedures. Only probabilistic methods (cross-stream and splitting) can be correct but their correctness depends on sample increment delimitation, increment extraction and integrity of increments and final sample. Recommendations are given for designing sampling procedures and designing sampling equipment. Common sources of error are described. The need for analytical specialists to be responsible for both sampling and sample processing is emphasized. 相似文献
98.
The to and fro motion of a bouncing ball on a flat surface is represented by a low-dimensional model. To describe the repeated reversals of the horizontal velocity of the ball, the elasticity of the ball has to be taken into account. We show that a simple fly-wheel model exhibits the observed hither and thither motion of elastic balls. The suggested model is capable of describing oblique impacts of spherical bodies, which can be important in many applications, including dynamical simulation of granular materials. We find that the behaviour of the bouncing fly-wheel is sensitive to the initial conditions, and the escape time plots are used to illustrate this observation. 相似文献
99.
100.
The interaction of sulfonated tetraphenylporphins H2 TPPS4(HCl)2 and in CuTPPS4 with poly-N-vinylpyrrolidone (PVP) is studied using small-angle neutron scattering, dynamic light scattering, visible spectrophotometry, and viscometry. It is shown that porphyrin molecules form complexes with PVP, thus charging the polymeric chain. 相似文献