Double-hole centers

Fig. 5. (a) Schematic of the Philips 2P Process for video disk repHcation (79) (b) configuration of a double-sided LaserVision disk where the hole at the center is not shown. S represents the transparent substrate A, the primer layer L, lacquer with picture and sound information in the form of pits M,... 

Ionization of DNA s solvation shell produces water radical cations (H20 ) and fast electrons. The fate of the hole is dictated by two competing reactions hole transfer to DNA and formation of HO via proton transfer. If the ionized water is in direct contact with the DNA (F < 10), hole transfer dominates. If the ionized water is in the next layer out (9 < r < 22), HO formation dominates [67,89,90]. The thermalized excess electrons attach preferentially to bases, regardless of their origin. Thus the yield of one-electron reduced bases per DNA mass increases in lockstep with increasing F, up to an F of 20-25. This means that when F exceeds 9, there will be an imbalance between holes and electrons trapped on DNA, the balance of the holes being trapped as HO . At F = 17, an example where the water and DNA masses are about equal, the solvation shell doubles the number of electron adducts, increasing the DNA-centered holes by a bit over 50% [91-93]. 

For higher pressures, double-acting pistons are employed (Fig Ex 20). In this press, the center plate has a lapped hole in which 2 pistons move. The sample is placed between the... 

The theory and instrumentation of Fourier transform mass spectrometry (FTMS) have been discussed extensively in this book and elsewhere [21-23]. All experiments were performed on a Nicolet prototype FTMS-1000 Fourier transform mass spectrometer previously described in detail [24] and equipped with a 5.2 cm cubic trapping cell situated between the poles of a Varian 15 in. electromagnet maintained at 0.85 T. The cell was constructed in our laboratory and utilizes two 80 transmittance stainless steel screens as the transmitter plates. This permits irradiation with a 2.5 kW Hg-Xe arc lamp, used in conjunction with a Schoeffel 0.25 m monochromator set for 10 nm resolution. Metal ions are generated by focusing the beam of a Quanta Ray Nd YAG laser (either the fundamental line at 1064 nm or the frequency doubled line at 532 nm) into the center-drilled hole (1 mm) of a high-purity rod of the appropriate metal supported on the transmitter screen nearest to the laser. The laser ionization technique for generating metal ions has been outlined elsewhere [25]-... 

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