Forces between a single atom and its distant mirror image

An excited-state atom whose emitted light is backreflected by a distant mirror can experience trapping forces, because the presence of the mirror modifies both the electromagnetic vacuum field and the atom's own radiation reaction field. We demonstrate this mechanical action using a single trapped barium ion. We observe the trapping conditions to be notably altered when the distant mirror is translated across an optical wavelength. The well-localized barium ion enables the spatial dependence of the forces to be measured explicitly. The experiment has implications for quantum information processing and may be regarded as the most elementary optical tweezers.     

Effects of gemini surfactants on egg phosphatidylcholine bilayers in the fluid lamellar phase

The influence of 1,4-butanediamonium-N,N'-dialkyl-N,N,N',N'-tetramethyl dibromides (CmA, m = 7-16 is the number of alkyl carbons) on the egg yolk phosphatidylcholine (EYPC) bilayer thickness and lipid surface area at the bilayer-aqueous phase interface is studied using X-ray diffraction on fluid lamellar CmA + EYPC + H2O phases as a function of CmA:EYPC and H2O:EYPC molar ratios and the alkyl chain length m. At the constant CmA:EYPC = 0.4 and H2O:EYPC = 18 molar ratios, the CmA induced bilayer thickness decrease shows a minimum and the lipid surface area increase a maximum at the alkyl chain length m = 9. The obtained results are discussed in the context of a structural perturbation model of the cut-off effect in biological potencies of surfactants which occurs when increasing the alkyl substituent chain length above the critical value.     

New approach to the measurement of the nonlinear refractive index of short (<25 m) lengths of silica and erbium-doped fibers

The nonlinear refractive index n2 of silica fiber (24 m) and erbium-doped fiber (10 m) is measured to within an accuracy of 5% by use of time-delayed photorefractive beam coupling of intense 53-ps, 1.064-microm pulses that experience self-phase modulation in the fibers. The resultant induced grating autocorrelation response yields a value of n2/A(eff) and a calibration standard for the fiber. A phase shift of the order of 0.19pi can be detected and is limited only by laser amplitude fluctuations. A unique advantage of this technique is its ability to measure n2 accurately in short lengths (z < or = 25 m) of fiber, whereas other approaches typically use much longer lengths of fiber (z > or = 100 m).     

MV-Algebra Pasting

Z. Rieanová proved that every D-lattice is a set-theoretical union of MV-algebras. These MV-algebras are blocks in the D-lattice. There is a dual question: How can we construct a D-poset from a given collection of MV-algebras. To solve this problem we use the pasting technique. We define an admissible system of MV-algebras and we prove that the pasting of this system is a D-poset.     

Ueber das Verhalten der Schellackharzs?uren bei der Trennung von Fetts?uren und Harzs?uren nach Gladding und nach Twitchell

Ohne ZusammenfassungAus dem Laboratorium des k. k. technologischen Gewerbe-Museums in Wien.     

Einen Apparat zur Bestimmung-der Verbrennungsw?rme

Ohne Zusammenfassung     

Corrigendum to “1/f Noise and intermittency due to diffusion of point defects in a semiconductor material” [Physica A 282 (2000) 108]

In the above-mentioned paper, the total rate of generation is defined by (unnumbered equation in Chapter 4.2 after Eq. (21)); in this equation the factor (1−c_d+) is missing. As a consequence, Eqs. (22)–(30) and Fig. 4 in the original paper have to be revised which is presented in this corrigendum. Numbering of references remains unchanged.     

Structure-Activity Relationship in Ambergris-Type Woody Odorants possessing a hydronaphthalene skeleton

A series of methyl hydronaphthyl alcohols, formates, acetates, and ketones were prepared and their odour properties evaluated. Minor structural changes, even opposite to the osmophoric group, were found to have major effects on the odour. ¹³C? NMR shift assignments of the hydronaphthyl derivatives are presented.