Plasmonic nanofabrication by long-range excitation transfer via DNA nanowire

Driven by the demand for ongoing integration and increased complexity of today's microelectronic circuits, smaller and smaller structures need to be fabricated with a high throughput. In contrast to serial nanofabrication techniques, based, e.g., on electron beam or scanning probe methods, optical methods allow a parallel approach and thus a high throughput. However, they rarely reach the desired resolution. One example is plasmon lithography, which is limited by the utilized plasmonic metal structures. Here we show a new approach extending plasmonic lithography with the potential for a highly parallel nanofabrication with a higher level of complexity based on nanoantenna effects combined with molecular nanowires. Thereby femtosecond laser pulse light is converted by Ag nanoparticles into a high plasmonic excitation guided along attached DNA structures. An underlying poly(methyl methacrylate) (PMMA) layer acting as an electron-sensitive resist is so structured along the former DNA position. This apparently DNA-guided effect leads to nanometer grooves reaching even micrometers away from the excited nanoparticle, representing a novel effect of long-range excitation transfer along DNA nanowires.     

Investigations into the properties of emulsifiers in yeast-leavened dough by means of infrared spectroscopy

High-resolution infrared (IR) spectra of emulsifiers for yeast-leavened bread were measured together with those of the individual components of wheat flour. Using the IR reflection technique, the entire dough was also investigated to give an insight into the development of structures in dough. The emulsifiers react with different components of wheat flour in a specific way. Using IR spectroscopy exact data for the strength of bonding and the kind of bonding between emulsifier and dough component can be obtained.     

Exploration–exploitation trade-off features a saltatory search behaviour

Searching experiments conducted in different virtual environments over a gender-balanced group of people revealed a gender irrelevant scale-free spread of searching activity on large spatio-temporal scales. We have suggested and solved analytically a simple statistical model of the coherent-noise type describing the exploration–exploitation trade-off in humans (‘should I stay’ or ‘should I go’). The model exhibits a variety of saltatory behaviours, ranging from Lévy flights occurring under uncertainty to Brownian walks performed by a treasure hunter confident of the eventual success.     

Elektronische und sterische Substituenteneinflüsse auf die UV/VIS-Absorptionsspektren der Phenylfulgidisomeren

Electronic and Steric Substituent Influences on the U.V./VIS-Absorption Spectra of Phenylfulgide Isomers The u.v./vis spectral data of a large number of phenylfulgides (E-, Z-, E-E-, E-Z-, Z-E-, Z-Z-isomers, 1.8a-dihydronaphthalenes) are presented. An increase of the number of phenyl rings as well as substitution of the phenyl rings cause correlatable bathochromic spectral shifts. Steric influences became obvious by introducing methyl groups, by coplanarization of phenyl groups and in the series of isomers. By means of PPP calculations shifts in position and/or intensity of absorption bands are ascribed to the substituent effects. The calculated band polarization of E(E-E)-isomers are in agreement with the results of polarization spectra in oriented liquid crystal mesophases. The polarization spectra allow the assignment of the longwave absorption band to the S₂ ← S₀ and S₁ ← S₀ electronic transitions for E-E-Isomers with a C_2v-symmetry.     

THEORETICAL APPROACHES TO DESIGN OF PRECIPITATION SYSTEMS: THE PRESENT STATE OF THE ART

Theoretical methods suggested in the literature for the design of precipitation systems under batch and continuous operation are reviewed. Expressions relating precipitation conditions to the particulate properties of the resulting suspension, namely its crystal size distribution and filtration resistance, are derived. Application of these expressions to precipitation systems design is discussed and illustrated by practical examples. The limits of applicability of the reviewed methods are indicated.