Stroboscope method

Stroboscopic Method.—This method was developed a few years ago by the writer in collaboration with M. Schiffer, and is based on the transformation theory of differential equations.20 We shall give here only the heuristic approach to this method, referring for its analytical proof to other published material.21... 

Examples of Application of the Stroboscopic Method.— We can consider two differential equations. 

One can also obtain the theory of synchronization by the stroboscopic method. If one starts with the differential equation... 

As the principal aim of the stroboscopic method is to obviate this difficulty by reducing the problem to the determination of stability of singular points, we include a brief statement of this approach. 

It is necessary to show that the subharmonic resonance whose existence we have just ascertained is stable. Here the condition of stability is very simple, since in the stroboscopic method we deal with the stability of the singular point (and not of the stationary motion). 

L. Mandelstam and N. Papalexi performed an interesting experiment of this kind with an electrical oscillatory circuit. If one of the parameters (C or L) is made to oscillate with frequency 2/, the system becomes self-excited with frequency/ this is due to the fact that there are always small residual charges in the condenser, which are sufficient to produce the cumulative phenomenon of self-excitation. It was found that in the case of a linear oscillatory circuit the voltage builds up beyond any limit until the insulation is ultimately punctured if, however, the system is nonlinear, the amplitude reaches a stable stationary value and oscillation acquires a periodic character. In Section 6.23 these two cases are represented by the differential equations (6-126) and (6-127) and the explanation is given in terms of their integration by the stroboscopic method. 

The first picosecond pulse radiolysis experiment was carried out in the late 1960s by the so-called stroboscopic method (generally pomp and probe method) at University of... 

A simplified instrument for the measurement of fluorescent lifetimes using the stroboscopic method has been described by Brown (67). The major virtue of this system is that it makes use of a Tektronix oscilloscope to obtain all the necessary trigger pulses, including a trigger of continuously variable delay. Since most laboratories are equipped with a good oscilloscope, the need to purchase expensive trigger-delay apparatus is thus eliminated. 

Glasses. Pearson and Peterson 98) studied extensively the fluorescent decay properties of terbium in Calibo base glass which has the composition CaO, 20 Li20, 10 B203, 70 mole per cent. All their data was taken using a stroboscopic method. 

Stroboscopic method. In this method the photomultiplier is also gated or pulsed having an on-time of nanosecond or subnanosecond duration during which it operates at very high gain. The flash lamp and the detector systems are synchronized such that a suitable delay can be introduced between the two. The gated photomultiplier samples the photocurrent each time the lamp fires and the photocurrent is thus proportional to the... 

Merely as a result of software changes, the stroboscope method with our experimental setup afforded a time resolution of a few microseconds (Souvignier and Gerwert, 1992). 

Improvements in time resolution in the stroboscopic method were achieved at the University of Tokyo by use of a twin linac system in which one aceelerator delivers the electron pulse to the sample and the other generates the Cerenkov light pulse used as the analyzing light [151]. Both linacs are driven by the same microwave source and delay between the electron pulse and the light pulse is achieved by phase shifters [151a]. The result is that the time interval between these two pulses is less than 3 ps. 

The lifetime of the photo-induced state in a given material dictates the instruments required for the determination of its structure. The smaller is the lifetime of such a species, the more chalienging the experiment becomes. These instmmental challenges are divisible into four categories steady-state methods (t > min), pseudo-steady-state methods (ms < Tq < min), and stroboscopic methods using a pulsed X-ray source generated by means of either a mechanical chopper (/as instrumental requirements as a function of time. 

Figure 2-4. A schematic diagram of die relative timing systems between laser, x-ray and sample photo-conversion hfetime. The nature of steady-state, pseudo-steady-state (in its simplest form) and stroboscopic pump-probe mediods are illustrated. The absolute timing for each method is on a separate scale die entire experiment is shown for die steady-state mediods the pseudo-steady-state representation shows up to the beginnings of die first data-collection frame the stroboscopic representation illustrates a regular pattern that occurs diroughout the experiment. Stroboscopic pseudo-steady-state methods are not represented here per se, but they essentially represent a combination of the basic pseudo-steady-state and stroboscopic methods shown here...

CeS 3 (and LaSnz), CePdz. The compounds have the cubic AuCu3 structure, for which the basic (tSR properties have been discussed in sect. 5.2.3. The study by Wehr et al. (1984) is solely concerned with Knight shift measmements performed with the stroboscopic method. The observed Knight shifts K i = (see sect. 3.2.1) are on... 

Population genetics Deterministic selection equations Stroboscopic method... 

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