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131.
In the work presented herein, the potential use of La4Sr8Ti12−xFexO38−δ (LSTF) materials as electrodes for a new concept of solid oxide fuel cells, symmetrical fuel cells (SFCs), is considered. Such fuel cells use simultaneously the same material as anode and cathode, which notably simplifies the assembly and further maintenance of the cells. Therefore, we search for materials showing high conductivity in a wide range of oxygen partial pressures in addition to certain degree of catalytic activity for the oxidation of the fuel and reduction of the oxidant, respectively. The preliminary electrochemical experiments performed reveal that the overall conductivity increases notably upon Fe substitution, being the main contribution electronic n-type. The fuel cell tests indicate that LSTF composites with YSZ and CeO2 perform reasonably well under H2 conditions, although the performance in methane is rather modest and require further optimisation.  相似文献   
132.
A new process of management of waste of composite materials from Sheet Moulding Compounds (SMC), as reinforcing fillers for thermoplastic materials, including both mechanical and chemical processes is proposed in this paper. Communited SMC being composed of coated glass fibres intimately mixed with calcium carbonate powder, their reinforcing power is low. First, the fibrous part was increased by partial dissolution of calcium carbonate present in the crushed products SMC. Second, a process of partial solvolysis was developed aiming at strong increasing the interfacial mechanical properties by functionalising of SMC load incorporated into polypropylene/grafted maleic anhydride polypropylene (PP/PPgma). At this effect, we investigated a treatment with a hot triamine (diethylenetriamine, DETA) in order to create a functionalisation, after scission of the bond ester of unsaturated polyester, as bridging amino-succinimide.The effect of this recycling way by partial solvolysis was checked from the mechanical properties of the resulting reinforced PP/PPgma material: Although a lower of Young modulus, better yield stress and especially resilience were observed.  相似文献   
133.
This article proposes a scheme for the on-line adjustment of three mode controller settings based on experimental measurements of closed-loop performance. It uses a recently developed heuristic tuning procedure to identify estimated process parameters. This method may give rise to conflicting estimates. Fuzzy Set theory is applied to manage the situation in terms of a fuzzy conjunction to combine the various estimates. PID control was chosen because of its wide use in the industrial environment due to driving simplicity and robustness. The article shows design, development, and computer simulation aspects.  相似文献   
134.
The purpose of this study was to examine whether anxiety-related cognitive bias for threat is stronger for threatening pictures than for threatening words. Spider-phobic participants (n?=?31 ) and control participants (n?=?33) performed a pictorial and linguistic spider Stroop task. Spider-phobic participants showed a marked bias for threat. However, this bias was similar for pictures and for words, although the spider-phobic group evaluated the pictures as being more aversive. The results suggest that automatic processing of threatening information in people with phobias is triggered in an on-off fashion, independent of subjective threat of the stimuli. This lack of distinction in automatic processing of weak and strong predictors of danger may be fundamental to the irrational nature of anxiety disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
135.
不能移动封隔器管柱是油气井封隔器完井的一种常见类型 ,在井内压力、温度、流体 (井内压力、温度、流体简称井内条件 ,下同 )发生变化时 ,不能移动封隔器管柱受力分析是保证井下安全和完井作业成功的关键 ,同时该管柱受力分析与自由移动封隔器管柱受力分析有很大的差别。文中对不能移动封隔器管柱变形受力的有关问题进行了分析、推导和讨论 ,并给出了算例。  相似文献   
136.
Precise timing and asynchronous I/O are appealing features for many applications. Unix kernels provide such features on a per‐process basis, using signals to communicate asynchronous events to applications. Per‐process signals and timers are grossly inadequate for complex multithreaded applications that require per‐thread signals and timers that operate at finer granularity. To respond to this need, we present a scheme that integrates asynchronous (Unix) signals with user‐level threads, using the ARIADNE system as a platform. This is done with a view towards support for portable, multithreaded, and multiprotocol distributed applications, namely the CLAM (connectionless, lightweight, and multiway) communications library. In the same context, we propose the use of continuations as an efficient mechanism for reducing thread context‐switching and busy‐wait overheads in multithreaded protocols. Our proposal for integrating timers and signal‐handling mechanisms not only solves problems related to race conditions, but also offers an efficient and flexible interface for timing and signalling threads. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
137.
王娟  张建可 《真空与低温》1995,1(3):149-152
着重介绍了静态法测试低温下(-100~50℃)液体饱和蒸气压的原理及方法,给出了低温下液体全氟三乙胺饱和蒸气压的测试结果,并进行了讨论。  相似文献   
138.
The ability of fermentative CO2 to blow off the volatile compounds that are synthesized during fermentation has been studied. Model solutions simulating a fermenting must were purged at different CO2 flow rates and temperatures, and the amount of volatile compounds blown off by the stream of CO2 was recorded by high-resolution gas chromatography. Data showed that under normal fermenting conditions, fatty acid ethyl esters and some fusel alcohol acetates are blown off the solution at a high rate. The maximum loss rate was observed for ethyl decanoate. The purging speed is doubled when temperature increases from 17 °C to 27 °C. Losses can be interpreted by a linear model and are a function of the compound and the flow rate of CO2. These models allow us to reconstruct the volatile synthesis vs time functions through graphic calculus and to estimate the proportion of volatile material retained, hydrolysed and purged. Synthesis takes place during the tumultuous period of fermentation together with CO2 production that blows off the volatile material. Hydrolysis takes place in the last stages of fermentation. In a 10-1 open fermenter, up to 80% of volatile material can be blown off while an average of 10% is retained. Residual esterase activity accounts for about 20% of the total amount of ester synthesized.  相似文献   
139.
The present paper describes a new algorithm to calculate the watershed transform through rain simulation of greyscale digital images by means of pixel arrowing. The efficiency of this method is based on limiting the necessary neighbouring operations to compute the transform to the outmost, and in the total number of scannings performed over the whole image. The experiments demonstrate that the proposed algorithm is able to significantly reduce the running time of the fastest known algorithm without involving any loss of efficiency.  相似文献   
140.
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