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31.
The stability of a rusted steel surface exposed to a 0.11 M sodium sulphate solution has been studied. Electrochemical impedance spectroscopy, polarization resistance and atomic absorption analysis techniques were used in conjunction with mild steel specimens rusted in a rural atmosphere and treated with different concentrations of phosphoric acid. Since most of the impedance diagrams obtained differ from the typical semicircle, it is not clear how to obtain kinetic information on the corrosion process. The polarization resistance technique gives more useful data.  相似文献   
32.
In 2011, a vertical‐slot fish pass was built at the Coimbra Açude‐Ponte dam (Mondego River, Portugal), approximately 45 km upstream from the river mouth. The performance of this infrastructure for sea lamprey passage was evaluated between 2011 and 2015 using several complementary methodologies, namely radio telemetry [conventional and electromyogram (EMG)], passive integrated transponder (PIT) telemetry and electrofishing surveys. During the study period, the electrofishing revealed a 29‐fold increase in the abundance of larval sea lamprey upstream of the fish pass. Of the 20 radio‐tagged individuals released downstream from the dam, 33% managed to find and successfully surpass the obstacle in less than 2 weeks, reaching the spawning areas located in the upstream stretch of the main river and in one important tributary. Fish pass efficiency was assessed with a PIT antenna installed in the last upstream pool and revealed a 31% efficiency, with differences between and within migratory seasons. Time of day and river flow significantly influenced the attraction efficiency of the fish pass, with lampreys negotiating it mainly during the night period and when discharge was below 50 m3 s?1. Sea lampreys tagged with EMG transmitters took 3 h to negotiate the fish pass, during which high muscular effort was only registered during passage, or passage attempts, of the vertical slots. The use of complementary methodologies provided a comprehensive passage evaluation for sea lamprey, a species for which there is a considerable paucity of valuable data concerning behavioural, physiological and environmental influences on obstacle negotiation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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Ensuring models’ consistency is a key concern when using a model‐based development approach. Therefore, model inconsistency detection has received significant attention over the last years. To be useful, inconsistency detection has to be sound, efficient, and scalable. Incremental detection is one way to achieve efficiency in the presence of large models. In most of the existing approaches, incrementalization is carried out at the expense of the memory consumption that becomes proportional to the model size and the number of consistency rules. In this paper, we propose a new incremental inconsistency detection approach that only consumes a small and model size‐independent amount of memory. It will therefore scale better to projects using large models and many consistency rules. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
35.
This paper presents two methods for automatic segmentation of images of faces captured in long wavelength infrared, allowing a wide range of face rotations, expressions and artifacts (such as glasses and hats). We also present the validation of segmentation results using a recognition method to show the impact of the segmentation accuracy on the recognition. The paper presents two different approaches (one aimed at real-time performance and the other at high accuracy) and compares their performance against three other previously published methods. The proposed approaches are based on statistical modeling of pixel intensities and active contour application, although several other image processing operations are also performed. Experiments were performed on a total of 893 test images from four public available databases. The obtained results improve on previous existing methods up to 29.5 % for the first measure error (E 1) and up to 34.7 % for the second measure (E 2), depending on the method and database. Regarding the computational time, our proposals improve up to 63.32 % when compared with the other proposals. We also present the validation of the various segmentation methods that are presented by applying a face recognition method.  相似文献   
36.
The lower halides of zinc, namely, ZnCl2, ZnBr2, and ZnI2, may act as network formers in glasses that also contain modifying alkali halides such as KCI, KBr, KI, NaI, or CsI. Compositions which contain only Br or I anions are of particular interest because of their extended infrared transmission, which includes the ∼10-μm region, in addition to full visible transparency. A series of modified zinc halide glasses were prepared and characterized by differential scanning calorimetry, middle and far Fourier transform infrared spectroscopy, and polarized Raman spectroscopy. T g values were characteristically low, around 40°C. Bulk glass infrared transmission up to 15 to 20 μm was recorded. The most probable glass structures are discussed and compared to oxide glass models. An attenuation of  0.001 dB/km has been projected as a possible intrinsic minimum for optical fibers operating near ∼6 μm.  相似文献   
37.
采用间苯二酚-甲醛树脂优化钢丝帘线粘合   总被引:1,自引:0,他引:1       下载免费PDF全文
新品种的间苯二酚-甲醛树脂中的游离间苯二酚含量极低,且不再具有吸湿性。考察了间苯二酚-甲醛树脂(Penacolite B-20-S)、硼酰化钴和不溶性硫黄的用量对钢丝粘合胶与镀铜钢丝粘合性能的影响。结果表明,树脂/钴盐粘合体系比单纯的钴盐粘合体系的粘合性能好得多。仅考虑粘合性能时,粘合体系最佳配方为:Penacolite B-20-S树脂4,硼酰化钴(活性钴)0.1,不溶性硫黄(活性)7.1,HMMM(活性)2.66。  相似文献   
38.
Disordered carbon materials with high porosity were prepared through the pyrolysis of TiO2/poly(furfuryl alcohol) composites, obtained by the sol-gel method. The composites were prepared starting from titanium tetra-isopropoxide (TTIP) and furfuryl alcohol (FA) as precursors. Two different synthetic procedures for our composites were carried out, based on the addition of furfuryl alcohol (FA) before or after the TiO2 nanoparticles formation. Also, different TTIP/FA ratio was tested. The hybrid materials obtained by both synthetic routes were pyrolyzed, under argon flow, at 900 °C producing novel TiO2/carbon composites. All samples were characterized by XRD, FT-IR, DR-FTIR, Raman spectroscopy and TEM. Results indicated the effective FA polymerization on TiO2 (anatase) nanoparticles, and polymer conversion to disordered carbon after the pyrolysis, simultaneously with TiO2 anatase-rutile phase transition. The resulting TiO2/carbon composites were treated with HF solution aiming the oxide dissolution, yielding an extremely porous carbon material as insoluble fraction. The morphology of these porous carbon materials is strongly dependent on the synthetic route adopted for the composite precursor, varying from carbon foam to highly ordered hollow microspheres.  相似文献   
39.
Journal of Scheduling - Rapid growth of demand for remote computational power, along with high energy costs and infrastructure limits, has led to treating power usage as a primary constraint in...  相似文献   
40.
Pattern Analysis and Applications - Digital holography is an imaging process able to recreate three-dimensional representations of objects from recording pattern interference among distinct waves....  相似文献   
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