The flavour of cape gooseberry (Physalis peruviana L.)

European Food Research and Technology - The volatile constituents of cape gooseberry (Physalis peruviana L.) were characterized using liquid/liquid extraction and fractionation of the flavour...     

Dielectric–Semiconductor Interface Limits Charge Carrier Motion at Elevated Temperatures and Large Carrier Densities in a High‐Mobility Organic Semiconductor

The fundamental nature of charge transport in highly ordered organic semiconductors is under constant debate. At cryogenic temperatures, effects within the semiconductor such as traps or the interaction of charge carriers with the insulating substrate (dipolar disorder or Fröhlich polarons) are known to limit carrier motion. In comparison, at elevated temperatures, where charge carrier mobility often also decreases as function of temperature, phonon scattering or dynamic disorder are frequently discussed mechanisms, but the exact microscopic cause that limits carrier motion is debated. Here, the mobility in the temperature range between 200 and 420 K as function of carrier density is explored in highly ordered perylene‐diimide from 3 to 9 nm thin films. It is observed that above room temperature increasing the gate electric field or decreasing the semiconducting film thickness leads to a suppression of the charge carrier mobility. Via X‐ray diffraction measurements at various temperatures and electric fields, changes of the thin film structure are excluded as cause for the observed mobility decrease. The experimental findings point toward scattering sites or traps at the semiconductor–dielectric interface, or in the dielectric as limiting factor for carrier mobility, whose role is usually neglected at elevated temperatures.     

Design of 5.9 ghz dsrc-based vehicular safety communication

The automotive industry is moving aggressively in the direction of advanced active safety. Dedicated short-range communication (DSRC) is a key enabling technology for the next generation of communication-based safety applications. One aspect of vehicular safety communication is the routine broadcast of messages among all equipped vehicles. Therefore, channel congestion control and broadcast performance improvement are of particular concern and need to be addressed in the overall protocol design. Furthermore, the explicit multichannel nature of DSRC necessitates a concurrent multichannel operational scheme for safety and non-safety applications. This article provides an overview of DSRC based vehicular safety communications and proposes a coherent set of protocols to address these requirements     

Reconfigurable receiver approach for future wireless terminals

An overview on RF-front-end architectures and technologies for future reconfigurable mobile communication is given. A favourable solution for fourth mobile generation is an extension of traditional cellular parameters by OFDM-based systems like WLAN. Therefore, an approach for widely reconfigurable receivers considering a variety of different standards, with the example of combining WCDMA and WLAN front-end into one architecture, is presented in this paper. RF-front-end key components like low noise amplifiers, mixers, and frequency synthesizers, as well as baseband variable gain amplifiers and filters are treated, particularly with regard to reconfigurable systems.     

大功率UPS电源的新原理

过去几年里，中小功率的UPS电源设计已经越来越多的采用无变压器电路原理，这不仅使得成本进一步优化，而且将给制造技术带来全新的面貌。随着UPS电源向高功率领域扩展，这一电路原理还不能完全的适用，还需要增添新的原理。本文介绍了关于这一新的电路原理及其控制结构，它使无变压器UPS电源的新潜力得以发挥。文章给出了这一技术的基本层面，并展示了一系列高功率UPS电源的新的研究成果。     

Highly Robust Indium‐Free Transparent Conductive Electrodes Based on Composites of Silver Nanowires and Conductive Metal Oxides

A hybrid approach for the realization of In‐free transparent conductive layers based on a composite of a mesh of silver nanowires (NWs) and a conductive metal‐oxide is demonstrated. As metal‐oxide room‐temperature‐processed sol–gel SnO_x or Al:ZnO prepared by low‐temperature (100 °C) atomic layer deposition is used, respectively. In this concept, the metal‐oxide is intended to fuse the wires together and also to “glue” them to the substrate. As a result, a low sheet resistance down to 5.2 Ω sq^‐1 is achieved with a concomitant average transmission of 87%. The adhesion of the NWs to the substrate is significantly improved and the resulting composites withstand adhesion tests without loss in conductivity. Owing to the low processing temperatures, this concept allows highly robust, highly conductive, and transparent coatings even on top of temperature sensitive objects, for example, polymer foils, organic devices. These Indium‐ and PEDOT:PSS‐free hybrid layers are successfully implemented as transparent top‐electrodes in efficient all‐solution‐processed semitransparent organic solar cells. It is obvious that this approach is not limited to organic solar cells but will generally be applicable in devices which require transparent electrodes.     

电源优化器技术:集中式与分布式MPPT的分析和比较

本文在解释电池板不匹配现象的基础上分析了电池参数的微小变化影响PV陈列系统性能的原因。此外,文章深入剖析了用于解决电池板不匹配问题的电源优化器技术,并列举了与集中式最大功率点跟踪（MPPT）和传统解决方案相比,电源优化器支持的分布式MPPT的潜在优点。     

Carbon hard masks for etching sub-90 nm structures

Carbon hard mask structures have been used to etch a variety of materials typically used in sub 90 nm DRAM manufacture. The results indicate that carbon hard masks can be used very effectively to structure oxide, nitride and metal films giving the CD performance required for the technologies being investigated.     

MI-Pack: Increased confidence of metabolite identification in mass spectra by integrating accurate masses and metabolic pathways

Metabolite identification is of central importance to metabolomics as it provides the route to new knowledge. Automated identification of the thousands of peaks detected by high resolution mass spectrometry is currently not possible, largely due to the finite mass accuracy of the spectrometer and the complexity that one peak can be assigned to one or more empirical formula(e) and each formula maps to one or more metabolites. Biological samples are not, however, composed of random metabolite mixtures, but instead comprise of thousands of compounds related through specific chemical transformations. Here we evaluate if prior biological knowledge of these transformations can improve metabolite identification accuracy.Our identification algorithm - which uses metabolite interconnectivity from the KEGG database to putatively identify metabolites by name - is based on mapping an experimentally-derived empirical formula difference for a pair of peaks to a known empirical formula difference between substrate-product pairs derived from KEGG, termed transformation mapping (TM). To maximize identification accuracy, we also developed a novel semi-automated method to calculate a mass error surface associated with experimental peak-pair differences. The TM algorithm with mass error surface has been extensively validated using simulated and experimental datasets by calculating false positive and false negative rates of metabolite identification. Compared to the traditional identification method of database searching accurate masses on a single-peak-by-peak basis, the TM algorithm reduces the false positive rate of identification by > 4-fold, while maintaining a minimal false negative rate. The mass error surface, putative identification of metabolite names, and calculation of false positive and false negative rates collectively advance and improve upon related previous research on this topic [1, 2]. We conclude that inclusion of prior biological knowledge in the form of metabolic pathways provides one route to more accurate metabolite identification.