Gold nanoparticle growth on self-assembled monolayers of ferrocenyl-substituted terpyridine on graphite

In this contribution we demonstrate that densely packed gold nanoparticles can be grown by Volmer–Weber mode on ferrocenyl functionalized terpyridine (FcTerp) on graphite. FcTerp forms highly ordered and dense self-assembled monolayers (SAMs) on graphite which significantly reduces the diffusion length of gold atoms and increases the sticking coefficient compared to bare graphite. Both effects lead to an increased nucleation and thus, to the growth of densely packed gold nanoparticles with diameters in the nanometer range. The optical properties of the nanoparticles as well as their morphology and the structure of the SAMs were characterized by optical extinction spectroscopy and scanning tunneling microscopy.     

Self-assembled organic monolayers as high-resolution resists in rapid nonlinear processing with single femtosecond laser pulses

Femtosecond laser patterning of alkanethiol monolayers on gold-coated silicon substrates at λ=800 nm, τ<30 fs and ambient conditions has been investigated. Single-pulse processing allows one to selectively remove the organic coating. Subsequently, pattern transfer into the gold film via wet etching in ferri-/ferrocyanide solution is achieved. As demonstrated, burr-free patterning can be carried out over an extremely wide range of laser pulse fluences from above 2 J/cm² down to 0.5 J/cm². Moreover, at low fluences, sub-wavelength processing down to λ/5 is feasible. In particular, at a 1/e laser spot diameter of about 1 μm, holes with diameters of 160 nm and step edges below 80 nm are fabricated. These results emphasize the prospects of organic monolayers as high-resolution resists in rapid nonlinear femtosecond laser processing.     

Behavior of captive herring exposed to naval sonar transmissions (1.0-1.6 kHz) throughout a yearly cycle

Atlantic herring, Clupea harengus, is a hearing specialist, and several studies have demonstrated strong responses to man-made noise, for example, from an approaching vessel. To avoid negative impacts from naval sonar operations, a set of studies of reaction patters of herring to low-frequency (1.0-1.5 kHz) naval sonar signals has been undertaken. This paper presents herring reactions to sonar signals and other stimuli when kept in captivity under detailed acoustic and video monitoring. Throughout the experiment, spanning three seasons of a year, the fish did not react significantly to sonar signals from a passing frigate, at received root-mean-square sound-pressure level (SPL) up to 168 dB re 1 μPa. In contrast, the fish did exhibit a significant diving reaction when exposed to other sounds, with a much lower SPL, e.g., from a two-stroke engine. This shows that the experimental setup is sensitive to herring reactions when occurring. The lack of herring reaction to sonar signals is consistent with earlier in situ behavioral studies. The complexity of the behavioral reactions in captivity underline the need for better understanding of the causal relationship between stimuli and reaction patterns of fish.     

Efficient interdigitated back‐contacted silicon heterojunction solar cells

We present back‐contacted amorphous/crystalline silicon heterojunction solar cells (IBC‐SHJ) on n‐type substrates with fill factors exceeding 78% and high current densities, the latter enabled by a SiN_x /SiO₂ passivated phosphorus‐diffused front surface field. V_oc calculations based on carrier lifetime data of reference samples indicate that for the IBC architecture and the given amorphous silicon layer qualities an emitter buffer layer is crucial to reach a high V_oc, as known for both‐side contacted silicon heterojunction solar cells. A back surface field buffer layer has a minor influence. We observe a boost in solar cell V_oc of 40 mV and a simultaneous fill factor reduction introducing the buffer layer. The aperture‐area efficiency increases from 19.8 ± 0.4% to 20.2 ± 0.4%. Both, efficiencies and fill factors constitute a significant improvement over previously reported values. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Performance evaluation of artificial bee colony optimization and new selection schemes

The artificial bee colony optimization (ABC) is a population-based algorithm for function optimization that is inspired by the foraging behavior of bees. The population consists of two types of artificial bees: employed bees (EBs) which scout for new, good solutions and onlooker bees (OBs) that search in the neighborhood of solutions found by the EBs. In this paper we study in detail the influence of ABC’s parameters on its optimization behavior. It is also investigated whether the use of OBs is always advantageous. Moreover, we propose two new variants of ABC which use new methods for the position update of the artificial bees. Extensive empirical tests were performed to compare the new variants with the standard ABC and several other metaheuristics on a set of benchmark functions. Our findings show that the ideal parameter values depend on the hardness of the optimization goal and that the standard values suggested in the literature should be applied with care. Moreover, it is shown that in some situations it is advantageous to use OBs but in others it is not. In addition, a potential problem of the ABC is identified, namely that it performs worse on many functions when the optimum is not located at the center of the search space. Finally it is shown that the new ABC variants improve the algorithm’s performance and achieve very good performance in comparison to other metaheuristics under standard as well as hard optimization goals.     

Statischer Starkeffekt von Cadmium I und Cadmium II

Stark-effect patterns of neutral and singly ionized Cadmium emitted from an obstructed and constricted glow-discharge have been recorded. For hydrogen-like terms experiments agree with calculations obtained by perturbation theory.     

卡尔曼滤波分光光度法测定安钠加注射液中苯甲酸钠和咖啡因含量

将卡尔曼滤波与分光光度法结合,用于同时测定安钠加注射液中苯甲酸钠和咖啡因的含量,其平均回收率分别为99.90±0.32%,100.10±0.28%。本法也适用于其它多组分体系分析。     

Absorptionsspektren des Er3+-Ions in Scandiumvanadat und Scandiumphosphat bei verschiedenen Dotierungen

The optical absorption spectra of trivalent erbium in ScVO₄ single crystals and ScPO₄ powders with doping ratios between (500∶1) and (10∶1) have been obtained between 15,000 and 27,000 cm^?1. From the positions of the Stark components of (Sc, Er)VO₄ (100∶1) the five crystal field parametersB ₀ ² ,B ₀ ⁴ ,B ₀ ⁶ ,B ₄ ⁴ andB ₄ ⁶ have been determined. Moreover the paramagnetic resonance of (Sc, Er)VO₄ single crystals with doping ratios mentioned above have been examined. With these experimental results informations have been obtained about the doping with metal-ions of an essentially different ionic radius.