Search results for "beat"

An Interactive MIDI Accompanist

1998

The ability to infer beat and meter from music is one of the basic activities of musical cognition. After hearing only a short fraction of music, we are able to develop a sense of beat and to tap our foot along with the music. Even if the music is rhythmically complex, containing a range of different time values and possibly syncopation as well, we are capable of inferring the different periodicities present in the music and synchronizing to them. Simulating this activity with a computer program might seem, at first glance, to be simple. If a note onset (that is, an attack) occurs before the system expects it to occur, the estimated tempo is increased, and vice versa. In practice, however, …

Beatificationis Beati Paschalis Baylon ex Discalceatis Ordinis Minorum Regularis Observantiae Provinciae S. Ioannis Baptistae Regni Valentiae / Paulu…

1618

18F-fluorodeoxyglucose hypometabolism in cerebellar tonsil and flocculus in downbeat nystagmus.

2006

A patient with downbeat nystagmus was examined by F-fluorodeoxyglucose-positron emission tomography once while off and twice while on successful treatment with 4-aminopyridine. All positron emission tomography scans of the patient showed a reduced cerebral glucose metabolism bilaterally in the region of the cerebellar tonsil and flocculus/paraflocculus when compared with a normal database of the whole brain. An additional region-of-interest analysis revealed that 4-aminopyridine treatment lessened the hypometabolism. This finding supports the hypothesis that the cerebellar tonsil and (para-) flocculus play a crucial role in downbeat nystagmus. The hypometabolism might reflect reduced inhibi…

Articuli, & Positiones In Causa Processus informatiui Pro Beatificatione, & Canonizatione seruae Dei Sororis Paulae de S. Thoma Dominicanae. Quae obi…

1634

Sign. : []1, A12

Aplauso en la beatificación del martir inuicto, el beato Pedro Arbues, llamado comunmente el Maestro Epila, Canonigo de la Seo de Zaragoça. y prime…

1664

Sig. A-F4

Autonomous frequency stabilization of two extended cavity diode lasers at the potassium wavelength on a sounding rocket

2016

We have developed, assembled, and flight-proven a stable, compact, and autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during a sounding rocket flight by means of frequency modulation spectroscopy (FMS) of 39^K and offset locking techniques based on the beat note of the two ECDLs. The frequency stabilization as well as additional hard- and software to test hot redundancy mechanisms were implemented as part of a state-machine, which controlled the experiment completely autonomously throughout the entire flight mission.

Field-free molecular alignment for probing collisional relaxation dynamics

2013

International audience; We report the experimental study of field-free molecular alignment in CO2 gas mixtures induced by intense femtosecond laser pulses in the presence of collisional processes. We demonstrate that the alignment signals exhibit specific features due to nontrivial collisional propensity rules that tend to preserve the orientation of the rotational angular momentum of the molecules. The analysis is performed with a quantum approach based on the modeling of rotational J- and M-dependent state-to-state transfer rates. The present work paves the way for strong-field spectroscopy of collisional dynamics.

Quantum beats from dressed three-level atoms

1983

Abstract By extending a previously developed unitary transformation technique to dress three-level atoms by a strong driving radiation field, we show that quantum beats can be induced by the presence of the driving field also when the decay channels lead from a singlet to a doublet of lower energy. A qualitative explanation of this effect is presented, which is based on the quantum theory of measurement.

Determination of nuclear spins of short-lived isotopes by laser induced fluorescence

1980

Abstract The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p3P1 state is observed at 2537 A after excitation with the frequency doubled output of a pulse dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were c…

Echolocation signals of the plecotine bat, Plecotus macrobullaris Kuzyakin, 1965

2006

Plecotus macrobullaris was recorded in an alpine region in Switzerland. Like other species of the genus Plecotus, P. macrobullaris emitted multiharmonic, downward frequency-modulated signals consisting mostly of the 1st and the lower part of the 2nd harmonic. Signal structure depended on the distance to the background. The shortest signals (0.8 ms) were recorded close to the background. The first harmonic began at about 46 kHz and ended around 23 kHz. Signals were emitted in groups. The longest signals (up to 7.3 ms) were recorded above a meadow, far from background targets. These signals, which were more shallowly modulated, started at about 42 kHz and ended around 15 kHz. They occasionall…