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131.
An anomalously low isotope effect has been discovered in 20-kHz sonoluminescence of terbium chloride solutions in H2O-D2O mixtures. The intensity of luminescence in the characteristic 488-and 545-nm lines of the Tb3+ ion, which are observed against the solvent continuum (230–700 nm), increases with the content of D2O to a maximum value of 4.0 ± 0.4, whereas the isotope effect in photoluminescence of the same solutions reaches 10 ± 1.0. The result is explained using the model of nonexponential decay of sonoluminescence of Tb3+ ions. These ions, which are formed in an excited state in cavitation bubbles, first undergo radiative and radiationless deactivation in the gas phase. However, some excited ions enter the solution bulk, because the excitation lifetime is longer than the average bubble lifetime. At the first stage, the isotope effect is small, because the density of the gas phase is low and quenching by solvent molecules is weak. At the second stage, the isotope effect coincides with the effect in usual photoluminescence in the solution. The total decrease in the effect in sonoluminescence depends on the weight of the “gas” stage of deactivation of excited Tb3+ ions. 相似文献
132.
Sans résumé
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133.
Marek Gaździcki 《Zeitschrift fur Physik C Particles and Fields》1995,66(4):659-662
Data on the multiplicity of pions produced in nucleon-nucleon interactions and central collisions of identical nuclei are discussed using a statistical approach. It is argued that the suppression of the pion production observed at low energies (p
LAB
<15>15>c per nucleon) is due to entropy transfer to baryons. The enhancement of the entropy production in central S+S collisions at 200 GeV/c per nucleon may be interpreted as manifestation of the increase, by a factor of about 3, of the effective number of degrees of freedom in the early stage of the collision. 相似文献
134.
The nucleon emission induced by high-energy electrons is analysed in three experimental situations: electron-proton coincedence and single detection of electron or proton. The coincidence and proton detection experiments are recommended as sensible tools for studying the nuclear correlations. 相似文献
135.
136.
Chromatographic method for the isolation of active 40S and 60S subunits from rat liver polyribosomes
T Kopacz-Jodczyk A Paszkiewicz-Gadek W Lopaczyński W Ga?asiński 《Journal of chromatography. A》1984,287(2):329-335
A rapid and simple procedure for isolation of 40S and 60S ribosomal subunits by ion-exchange column chromatography is described. The dissociated ribosomes can be separated and non-ribosomal proteins and low-molecular-weight substances removed. An assessment by physicochemical and functional criteria showed that the ribosomal subunits obtained are active and sufficiently homogeneous. 相似文献
137.
Marek Gaździcki 《Acta Physica Hungarica A》1996,4(1-4):33-44
The dependence of pion and strangeness production on the number of participant nucleons and collision energy is discussed for central A+A collisions. A possible interpretation of the experimental results assuming transition to QGP is sketched within a simple statistical approach. 相似文献
138.
139.
140.
Ferenc F. Gaál Ljiljana S. Jovanović Zorka S. Jevrić Jolan N. Ilijević Velimir D. Canić 《Mikrochimica acta》1978,69(1-2):27-34
Summary Electroanalytical End-Point Determination of Hydrolytic Precipitation Titrations of Sulphate and OxalateThe possibilities of application of biamperometric and bipotentiometric end-point determination by means of various indicator electrodes are described. Several titrants were used. Best results were obtained with quinhydrone electrodes. Interference levels of several anions were established. The lowest concentration of oxalate and sulphate that can be determined is 5×10–4
M.
Zusammenfassung Die Anwendungsmöglichkeiten der biamperometrischen und bipotentiometrischen Endpunktbestimmung mittels verschiedener Indikatorelektroden wurden beschrieben. Es wurden einige Titranten benützt. Die besten Resultate wurden mit Chinhydronelektroden erhalten. Die störende Wirkung verschiedener Anionen wurde festgestellt. Die geringste bestimmbare Konzentration beider Anionen (Sulfat und Oxalat) ist 5·10–4 M.相似文献