跟踪直流大电流的低成本电流监控器

为了测量过载检测和保护时的直流大电流,设计者经常采用电流并联电阻器或环形磁芯,以及霍尔效应磁场传感器.这些方法都有缺点.例如,用一个10m Ω电阻器测量20A电流会白白耗散掉4W功率.     

Effective electrode configuration for selective stimulation with inner eye prostheses

The quality of visual perception with retinal prostheses strongly depends on the local selectivity. Electrode arrays at the surface of the retina should excite exclusively cells within a local area but they are expected to co-stimulate bypassing axons originating from ganglion cells of the outer regions. Long electrodes parallel to these axons are shown to be good candidates for avoiding the co-stimulation phenomenon. Efficiency of focal excitation depends on the length and resistance of the electrodes.     

Tuning the Intermolecular Electrostatic Interaction toward High-Efficiency and Low-Cost Organic Solar Cells

Organic solar cells (OSCs) have achieved much progress with rapidly increasing power conversion efficiencies (PCEs). It should be noted that the top-performance OSCs are generally consisted of active materials with complex chemical structures, resulting in high costs. Here, combining the material design and morphology control, high-efficiency OSCs are fabricated by a low-cost donor: acceptor blend. A completely non-fused electron acceptor named Tz is designed and synthesized via introducing thiazole units on both sides of a bithiophene core, which shows an outstanding PCE of 13.3% with a typical polythiophene donor. More importantly, optimization guidelines are presented to get excellent morphology for low-cost donor:acceptor systems. Three polythiophenes are selected, poly(3-hexylthiophene) and its two derivatives with electron-withdrawing substitutions (PDCBT and PDCBT-2F), as donors to fabricate the cell devices. The computational and experimental data reveal that decreasing the electrostatic interaction between polythiophene and Tz is the key to getting a suppressed miscibility and thus a high phase purity. This study provides insight into the molecular design and donor:acceptor matching requirements for high-efficiency and low-cost OSCs.     

Development of compatible wet-clean stripper for integration of CoWP metal cap in Cu/low-k interconnects

Implementation of CoWP metal caps into Cu/low-k integration schemes requires a wet stripper that not only gives efficient cleaning but also has good compatibility to CoWP and low-k dielectrics. This paper describes a novel non-fluoride CoWP compatible stripper, developed based on a systematic study of the effect of stripper components, i.e. solvent, corrosion inhibitor, and stripper pH. Electrochemical methods were used to characterize galvanic corrosion of the CoWP/Cu couple and to estimate CoWP etch rate. Our studies showed that a traditional fluoride stripper caused severe damage to CoWP capping layer. The new stripper achieved a good balance between cleaning efficiency and compatibility to CoWP and low-k dielectrics, and demonstrated significant advantages in electrical properties over the traditional fluoride stripper.     

How to improve intrinsic and extrinsic reliability of vias by process optimization

A systematic study of various processes and their impact on intrinsic reliability has been performed on Cu dual damascene interconnects. The most significant improvement for intrinsic reliability is the ‘break-through’ liner. A strong impact on stressmigration (SM) was revealed using a HDP based SiN deposition on top of Cu lines. Early failures in electromigration (EM) studies are present with insufficient cleaning processes. No reliability impact was detected with different plating and slurry chemistries and liner thickness increase. Extrinsic via reliability is assessed with a special test chip comprising 3E9 via/wafer. High ohmic vias are identified before and after thermal stress. As an example, the failure rates in Cu dual damascene levels with relaxed pitch before and after cleaning optimization are discussed.     

Induction of Vesicle Formation by Exposing Apple Tissue to Vacuum Impregnation

This paper demonstrates that vacuum impregnation of mature apple tissue in the presence of different sugars results in the formation of membrane vesicles inside the cells. Vesiculation is regarded to be a metabolic consequence of the impregnation process. Vesiculation is shown when the endocytic marker FM4-64 was impregnated into the apple tissue together with the sugar solutions. Vesicles were formed at the plasma membrane already 30 min after impregnation and remained inside the cells for at least 24 h, a metabolic process that was inhibited in the presence of chloroquine, a specific endosomic inhibitor. This phenomenon was not dependent on the osmotic strength when sucrose was used for impregnation. However, the vesiculation drastically dropped when a hypertonic trehalose solution was impregnated. We suggest that the impregnated sugars may not totally remain in the extracellular space between the cells, as normally believed, but at least a fraction might be incorporated into the cells.     

Purification and structural characterisation of lipid transfer protein from red wine and grapes

Lipid transfer proteins (LTP) play a major role in plant defence and are of particular interest due to their known ability to cause allergic reactions. These proteins are expressed in grapes and also remain detectable after vinification, especially in red wine. However, it remains unknown whether the protein undergoes any changes during the vinification process. Here, we present a purification method for LTPs from Dornfelder grapes and wine. By liquid-chromatography–mass spectroscopy (LC–MS/MS) we identified LTPs from two different species (Vitis vinifera and Vitis aestivalis). Additionally, the purified LTPs were characterised using spectrometric methods, confirming their high purity and structural stability during vinification. We conclude that LTPs are resistant to the alcohol content (13.5 vol%), acidic milieu of wine and other ingredients present during the vinification process, indicating that the allergenic potential of grape LTP is not diminished by the vinification process.     

The effect of temperature and radiation on flavonol aglycones and flavonol glycosides of kale (Brassica oleracea var. sabellica)

The winter crop kale has a complex profile of different glycosylated and acylated flavonol glycosides which may be affected by global warming. To the best of our knowledge, compound–climate relationships for flavonol aglycones and flavonol glycosides were established for the first time. The investigated 10 major flavonol glycosides responded structure-dependent in the investigated temperature range between 0 and 12 °C and the photosynthetic active radiation range between 4 and 20 mol m⁻² d⁻¹, e.g. the decrease in temperature led to an increase in sinapic acid monoacylated and diacylated quercetin glycosides, while the sinapic acid monoacylated kaempferol glycosides showed a maximum at 4.5 °C. Furthermore, the hydroxycinnamic acid residues and the different number of glucose moieties in the 7-O position affected the response of kaempferol triglucosides. Consequently, global warming would result in lower concentrations of antioxidant-relevant quercetin glycosides in winter crops, suggesting a production at e.g. higher altitudes due to lower temperature.