Full Width

The energy spectrum of the resonance states will be quasi-discrete it consists of a series of broadened levels with Lorentzian lineshapes whose full-width at half-maximum T is related to the lifetime by F = Fn. The resonances are said to be isolated if the widths of their levels are small compared with the distances (spacings) between them, that is... 

The full width at half height of these Lorentzian peaks is 2/x. One says that the individual peaks have been pressure or eollisionally broadened. 

No collector sHt is fitted, and the full width of the ion beam falls onto microchaimel plates which emit electrons. The emitted electrons strike a phosphor coating on the end of a fiber-optic cable (see Fiber optics). The phosphor emits photons which travel along the cable to the photodiode array. 

Thermal printing usually involves passing materials over a full-width array of electronically controlled heaters (a thermal printhead). This marks thousands of spots simultaneously, so pages print relatively quickly. Image data to control the printhead usually come from computer systems. Black-and-white and full-color systems are both practical. Color is slower and more cosdy to purchase and use, primarily because this involves three or four successive printing operations, one for each color used. 

Transition Widths and Strengths. The widths and strengths of spectroscopic transitions determine the information that can be extracted from a spectmm, and are functions of the molecular parameters summarized in Table 2. Detectivity is deterrnined by spectral resolution and transition strength. Resolution, the abiUty to distinguish transitions of nearly equal wavelength, depends on both the widths of the spectral features and characteristics of the instmmentation. Unperturbed transitions have natural, Av widths owing to the intrinsic lifetimes of the states involved. The full width at... 

Method of Feed The screening machine must be fed properly in order to obtain maximum capacity and efficiency. The feed should be spread evenly over the full width of the screen cloth and approach the screen surface in a direction parallel to the longitudinal axis of the screen and at as low a practical velocity as is possible. 

Flour and Feed Meal The roller mill is the traditional machine for grinding wheat and lye into high-grade flour. A typical mill used for this purpose is fitted with two pairs of rolls, capable of making two separate reductions. After each reduction the product is taken to a bolting machine or classifier to separate the fine flour, the coarse produc t being returned for further reduction. Feed is supphed at the top, where a vibratoiy shaker spreads it out in a thin stream across the full width of the rolls. 

Energy analyzers cannot be discussed without discussion of energy resolution, which is defined in two ways. Absolute resolution is defined as AE, the full width at half-maximum (FWHM) of a chosen peak. Relative resolution is defined as the ratio R of AE to the kinetic energy E of the peak energy position (usually its centroid), that is, R = AE/E. Thus absolute resolution is independent of peak position, but relative resolution can be specified only by reference to a particular kinetic energy. 

Optimum resolution, i. e. low full width at half-maximum (FWHM), is a trade-off between high count rate, i. e. low dead-time, and good spectral resolution. 

The energy resolution of an X-ray detector is experimentally defined by the full width at half maximum (FWHM) of the Mn-Ka line. The FWHM, in eV, can also be calculated by use of the relationship ... 

RAIRS spectra contain absorption band structures related to electronic transitions and vibrations of the bulk, the surface, or adsorbed molecules. In reflectance spectroscopy the ahsorhance is usually determined hy calculating -log(Rs/Ro), where Rs represents the reflectance from the adsorhate-covered substrate and Rq is the reflectance from the bare substrate. For thin films with strong dipole oscillators, the Berre-man effect, which can lead to an additional feature in the reflectance spectrum, must also be considered (Sect. 4.9 Ellipsometry). The frequencies, intensities, full widths at half maximum, and band line-shapes in the absorption spectrum yield information about adsorption states, chemical environment, ordering effects, and vibrational coupling. 

Fluctuating Gap Model Fowler-Nordheim fluorine-doped tin dioxide full width at half maximum geminate pair... 

Figure 9-29. (a) Emission of" ni-Ll PP al dilTcrenl exclusion laser pulse energies, (b) Full width ai half maximum and peak position ill" ihe m-LPPP emission versus cxcilalion laser pulse energy. 

Full width at half maximum Green fluorescent protein... 

In these equations A and np are the molar fractions of A and P (8 v) = v - vp is the difference between the resonance frequencies of the nuclei in positions A and P, usually determined from the low-temperature limit A is the full-width at half height in the absence of exchange (r - °°) and v is the variable radio frequency of the NMR experiment. 

In the fast exchange limit ft2 A2, a Lorentzian at the centre d>, is observed with full width at half height 2/T + A2/Q. In the ultrafast exchange limit discussed in the previous section, A2/fi 2/T, the line shape becomes independent of the exchange... 

Water flows in an open channel across a weir which occupies the full width of the channel. The length of the weir is 0.5 m and the height of water over the weir is 100 mm. What is the volumetric flowrate of water ... 

Fig. 5.20. Full width of nitrogen Q-branch CARS spectra measured at 295 K versus densities (squares) and calculated width using the MEG law (circles) [14]. Shown also are the error bar and the width measured in liquid nitrogen (triangle), (a) Density range up to 700 amagat. (b) Density range up to 100 amagat showing part of Fig. 5.20(a) in more detail...

---