简化混合处理器应用开发 FPGA分担DSP功能降低构建成本

随着大规模现场可编程逻辑阵列(FPGA)的成本降低,加上面向软件的FPGA设计工具的发展,使得FPGA器件获得更多的使用,既能处理过去DSP处理器领域的功能,同时大大降低了专用ASIC方案的风险和前期成本.     

Nano-Engineered Carbon Fibre-Based Piezoelectric Smart Composites for Energy Harvesting and Self-Powered Sensing

The integration of piezoelectric materials onto carbon fiber (CF) can add energy harvesting and self-power sensing capabilities enabling great potential for “Internet of Things” (IoT) applications in motion tracking, environmental sensing, and personal portable electronics. Herein, a CF-based smart composite is developed by integrating piezoelectric poly(3,4-ethylenedioxythiophene) (PEDOT)/CuSCN-coated ZnO nanorods onto the CF surfaces with no detrimental effect on the mechanical properties of the composite, forming composites using two different polymer matrices: highly flexible polydimethylsiloxane (PDMS) and more rigid epoxy. The PDMS-coated piezoelectric smart composite can serve as an energy harvester and a self-powered sensor for detecting variations in impact acceleration with increasing output voltage from 1.4 to 7.6 V under impact acceleration from 0.1 to 0.4 m s⁻². Using epoxy as the matrix for a CF-reinforced plastic (CFRP) device with sensing and detection functions produces a voltage varying from 0.27 to 3.53 V when impacted at acceleration from 0.1 to 0.4 m s⁻², with a lower output compared to the PDMS-coated device attributed to the greater stiffness of the matrix. Finally, spatially sensitive detection is demonstrated by positioning two piezoelectric structures at different locations, which can identify the location as well as the level of the impacting force from the fabricated device.     

从PCB和IC设计领域管理信号完整性

如果你考察我们试图用来获得应力模型或者类似模型的那些“邦迪”式(凑合)的方法,就会发现它可做不到有章可循。这就是为什么我们要花费更多的精力来试图确定需要何种模型,并判断哪种模型将为人们所接受。有待解决的最大的一个问题是,是否继续对器件的曲线来作假设,或者设法从一个确定性光刻的角度来推进问题的解决。EDA行业现在不再对模型采取消极的态度。现在,如果我们得不到所需要的东西,我们的过错将与模型的提供者一样严重。在研究90nm技术并迈向65nm节点的过程中,会出现两个层次上的信号完整性问题。在第一个层面上,你必须在数字域…     

A Novel Metal-Rich Anneal for In Vacuo Passivation of High-Aspect-Ratio Mercury Cadmium Telluride Surfaces

A new method for Cd-rich annealing of mercury cadmium telluride (MCT) was developed based on the observation that the deposition of Cd onto MCT by vacuum evaporation became self-limiting whenever the substrate temperature was above 70°C regardless of the Cd evaporation rate. Preliminary results indicated that this new method may be suitable for passivation of high-aspect-ratio MCT surfaces, for passivation at low temperatures, for in vacuo operation, and/or for vacancy annihilation in MCT. Furthermore, the process can be carried out in the conventional open-tube reactors used for molecular beam epitaxy, metalorganic chemical vapor deposition, and physical vapor deposition.     

Toward multiple maximum power point estimation of photovoltaic systems based on semiconductor theory

Environmental conditions, such as temperature, non‐uniform irradiation, and solar shading, deeply affect the characteristics of photovoltaic (PV) modules in PV‐assisted generation systems. Several local maximum power points (MPPs) are found in the power–voltage curve of PV systems constructed by series/parallel‐connected PV modules under partially shaded conditions. The characteristics of PV systems change unpredictably when multiple MPPs occur, so the actual MPP tracking (MPPT) becomes a difficult task. Conventional MPPT methods for the PV systems under partially shaded conditions cannot quickly find the actual MPP such that the optimal utilization of PV systems cannot be achieved. Based on the p–n junction semiconductor theory, we develop a multipoint direct‐estimation (MPDE) method to directly estimate the multiple MPPs of the PV systems under partially shaded conditions and to cope with the mentioned difficulties. Using the proposed MPDE method, the multiple MPPs of the PV systems under partially shaded conditions can be directly determined from their irradiated current–voltage and power–voltage characteristic curves. The performances of the proposed MPDE method are evaluated by examining the characteristics of multiple MPPs of PV systems with respect to different shading strengths and numbers of the shaded PV modules and also tested using the field data. The experimental results demonstrate that the proposed MPDE method can simply and accurately estimate the multiple MPPs of the PV systems under partially shaded conditions. The optimization of MPP control models and the MPPT for PV systems could be achieved promisingly by applying the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

„Smart“, Vernetzung und Komplexität – Ein Plädoyer für einen kritischeren Umgang mit dem Thema Vernetzung

Our daily life is already based on a very high level of connectivity and interconnectedness with many benefits but also with a growing threat level from cyberspace. Our critical infrastructure will also become more and more involved in this process of interconnectedness. Especially with the topic of “smart” many things are likely to get more comfortable and easier. Smart homes are to be controlled remotely, smart meters should decrease our energy consumption and smart grids should enable the transformation of the power supply system to renewable and sustainable energy production. The pictures conjured up by these topics are very colourful. But seldom the responsible people are aware of the consequences of an increasing interconnectedness. The results are complex systems with a completely different behaviour from our current machines. They are not controllable in the same way we used to do with machines until now. On the other hand it could be a high risk to merge the known insecure ICT systems with our critical infrastructure, especially with our power supply system. Our whole life is heavily dependent on the reliability of the power supply system and there is only one European power network. We should not risk this essential system for survival by increasing interconnectedness inconsiderately and without an adequate knowledge of complex systems.     

Novel,Robust, and Versatile Bijels of Nitromethane,Ethanediol, and Colloidal Silica: Capsules,Sub‐Ten‐Micrometer Domains,and Mechanical Properties

Bicontinuous, interfacially jammed emulsion gels (bijels) are a class of soft solid materials in which interpenetrating domains of two immiscible fluids are stabilized by an interfacial colloidal monolayer. Such structures form through the arrest of the spinodal decomposition of an initially single‐phase liquid mixture containing a colloidal suspension. With the use of hexalmethyldisilazane, the wetting character of silica colloids, ranging in size and dye content, can be modified for fabricating a novel bijel system comprising the binary liquid ethanediol–nitromethane. Unlike the preceding water‐lutidine based system, this bijel is stable at room temperature and its fabrication and resultant manipulation are comparatively straightforward. The new system has facilitated three advancements: firstly, we use sub 100 nm silica particles to stabilize the first bijel made from low molecular weight liquids that has domains smaller than ten micrometers. Secondly, our new and robust bijel permits qualitative rheological work which reveals the bijel to be significantly elastic and self healing whilst its domains are able to break, reform and locally rearrange. Thirdly, we encapsulate the ethanediol–nitromethane bijel in Pickering drops to form novel particle‐stabilized bicontinuous multiple emulsions that we christen bijel capsules. These emulsions are stimuli responsive – they liberate their contained materials in response to changes in temperature and solvency, and hence they show potential for controlled release applications.     

Mesure du Débit d’Absorption Spécifique (das) des téléphones mobiles — contribution du projetcomobio à la normalisation internationale

Human exposure to electromagnetic fields emitted by mobile phones is characterised by the Specific Absorption Rate (sar). This value corresponds to therf power absorbed by unitary mass of the equivalent tissue. It represents the basic restriction used to define limit of human exposure torf electromagnetic fields. Academic and industrial labs have contributed through thecomobio project to define international standards for mobile phones certification.