ABSTRACT
The delocalization of excitations in an ensemble of two-level systems with a strong disorder due to an external alternating acoustic or electric field is considered. The propagating modes are shown to appear if a ratio of the field amplitude to the frequency is large enough. Two complementary approaches, the static one similar to that of Anderson and the dynamic one related to Landau-Zener, are developed. It is shown that the field-induced relaxation mechanism can have a strong influence on the kinetics. The internal friction is argued to be vastly affected by the relaxation mechanism proposed.
ABSTRACT
We study the generation of excitations due to an "impurity" (static perturbation) placed into an oscillating Bose-Einstein condensed gas in the time-dependent trapping field. It is shown that there are two regions for the position of the local perturbation. In the first region the condensate flows around the impurity without generation of excitations demonstrating superfluid properties. In the second region the creation of excitations occurs, at least within a limited time interval, revealing destruction of superfluidity. The phenomenon can be studied by measuring the damping of condensate oscillations at different positions of the impurity.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Aged , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/pharmacokinetics , Bacteria/drug effects , Cochlea/drug effects , Drug Tolerance , Humans , Kidney/metabolism , Liver/metabolism , Nephrons/drug effects , Vestibule, Labyrinth/drug effectsABSTRACT
A statistical procedure, derived from a theoretical model of fracture growth, is used to identify a foreshock sequence while it is in progress. As a predictor, the procedure reduces the average uncertainty in the rate of occurrence for a future strong earthquake by a factor of more than 1000 when compared with the Poisson rate of occurrence. About one-third of all main shocks with local magnitude greater than or equal to 4.0 in central California can be predicted in this way, starting from a 7-year database that has a lower magnitude cut off of 1.5. The time scale of such predictions is of the order of a few hours to a few days for foreshocks in the magnitude range from 2.0 to 5.0.
ABSTRACT
A simple time-resolved Fabry-Perot spectrometer has been designed for the measurement of line profiles emitted by a pulsed plasma. The rotating mirror is used to scan the spatial image of the fringes. The intensity distribution of interference patterns can be observed within a scanning time of 25 nsec. The velocity of an accelerated copper plasma was measured by means of this system.
ABSTRACT
Chloromethyl phthalimide, oxymethyl phthalimide, and phthalimide are absorbed by the albino rat at a comparatively high rate. Only phthalimide, the metabolic product, will be recordable from fetuses, following oral administration of chloromethyl phthalimide and oxymethyl phthalimide topregnant rats. Those findings, in conjunction with metabolic studies applied to fetuses isolated by caesarian section, appear to suggest the occurrence of an intensive metabolism in fetal tissue. Certain differences established between results of thin-layer chromatography, on the one hand, and 15N studies, on the other, are likely to support the assumption that phthalimide is further metabolised by splitting the imide ring yielding phthalamic acid.
Subject(s)
Fetus/metabolism , Maternal-Fetal Exchange , Phthalimides/metabolism , Animals , Biodegradation, Environmental , Female , Half-Life , Pregnancy , Rats , Time FactorsABSTRACT
The organophosphate insecticide imidan includes a phthalimide group. Because of the structural relationship to the teratogenic compound thalidomide we have investigated its placental transfer and metabolic fate in rats. Its passage to embryonic tissues could be confirmed. After intraamniotic injection to the first amniotic cavity of the left uteri we could establish a distribution of imidan and 32P compounds throughout the uteri, the concentration depending upon the incubation time and the distances from the place of injection. The half-life of imidan, detected in the exterioized fetuses or in newborns, was 50--70 min. Imidoxon, i.e., the oxidized form of imidan, has a diminished half-life. This fact explicates the presence of imidoxon only in small concentrations after application of imidan.
