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排序方式: 共有321条查询结果,搜索用时 15 毫秒
101.
102.
This study elucidates the effect of cold rolling on the microstructure, corrosion and electrochemical response of the lean duplex stainless steel LDX 2101®. With thickness reductions of 0%, 20% and 40%, three different specimens are investigated in terms of microstructure (electron backscattered diffraction [EBSD] and energy-dispersive X-ray spectroscopy [EDS]), corrosion properties (ASTM G150, ASTM G61 and field testing), passive film properties (X-ray photoelectron spectroscopy) and electrochemical response (scanning Kelvin probe force microscopy [SKPFM]). It is shown that deformation of LDX 2101 leads to changes in the microstructure such as mechanical twinning and martensite formation. The combination of EBSD, EDS and SKPFM maps shows that the work function is clearly dependent on composition, deformation and local misorientation, but not on the crystallographic orientation of the grains in the microstructure. Zones with low work function are seen to have the highest pitting susceptibility, which includes deformed ferritic, martensitic phase and areas with a high concentration of dislocations such as grain boundaries and mechanical twins. The overall conclusion is that cold deformation up to a 40% thickness reduction has a significant influence on the microstructure, but a small impact on the corrosion resistance of LDX 2101. 相似文献
103.
Non-enzymatic browning (NEB) development was studied in dehydrated potato at 70 °C. It was related to the macroscopic and molecular properties and to water–solid interactions over a wide range of water activities. Time resolved 1H NMR, thermal transitions and water sorption isotherms were evaluated. Although non-enzymatic browning could be detected in the glassy state; colour development was higher in the supercooled state. The reaction rate increased up to a water content of 26 g/100 g of solids (aw = 0.84) and then decreased at higher water contents, concomitantly with the increase of water proton mobility. The joint analyses of NEB kinetics, water sorption isotherm and proton relaxation behaviour made it evident that the point at which the reaction rate decreased, after a maximum value, could be related to the appearance of highly mobile water. The results obtained in this work indicate that the prediction of chemical reaction kinetics can be performed through the integrated analysis of water sorption, water and solids mobility and the physical state of the matrix. 相似文献
104.
In this study, 4 experiments were carried out to investigate if segmental and structural information are represented separately in phonological encoding in speech production. In Experiments 1 and 2, a picture-word interference paradigm was used. Participants had to name a picture while a word was auditorily presented 150 ms after the onset of the target. In Experiments 3 and 4, participants had to read aloud lists of printed words (inductors) and then had to name a picture. Results of the first 3 experiments indicate that naming latencies are faster when target and interfering stimulus (in the first 2 experiments) and inductors (in the 3rd) share the same abstract phonological structure. The 4th experiment showed that the priming effect observed previously is due to facilitation of the first-syllable structure, supporting the notion that an abstract syllabic structure is used in phonological encoding. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
Christophe Serre Alejandro Pérez-Rodríguez Nuria Fondevilla Joan Ramon Morante Josep Montserrat Jaume Esteve 《Microsystem Technologies》2007,13(11-12):1655-1661
In this work, we present the design and optimization of an electromagnetic inertial microgenerator for energy scavenging applications, compatible with Si technology. It consists of a fixed micromachined coil and a movable magnet (inertial mass) mounted on a resonant structure (Kapton® membrane). The modeling of the device, based on a velocity damped resonator, has allowed to make a quantitative analysis of the capabilities of this simple device structure for the development of power generators for autonomous microsystem applications. The characterization of a first (not optimized) prototype has allowed the validation of the model, which is then used as a roadmap for a number of optimizations for the final device design. For this design, the model developed shows the possibility to achieve power levels up to hundreds of μW’s, with voltage levels compatible with the requirements of standard rectifying circuits. 相似文献
106.
In this paper two curvature adaptive methods of surface triangulation are presented. Both methods are based on edge refinement to obtain a triangulation compatible with the curvature requirements. The first method applies an incremental and constrained Delaunay triangulation and uses curvature bounds to determine if an edge of the triangulation is admissible. The second method uses this function also in the edge refinement process, i.e. in the computation of the location of a refining point, and in the re-triangulation needed after the insertion of this refining point. Results are presented, comparing both approaches. 相似文献
107.
Nuria Rodríguez Mercedes Medio‐Simn Gregorio Asensio 《Advanced Synthesis \u0026amp; Catalysis》2007,349(6):987-991
A chemoselective palladium‐catalyzed anaerobic oxidation of allylic and benzylic alcohols using an α‐bromo sulfoxide as a co‐oxidant is described for the first time. The catalyst system is simple and has a long life because of the allowance of phosphane ligands under the non‐aerobic conditions. The advantages of the described method include no overoxidation of primary alcohols to carboxylic acids because of the mild conditions applied, the tolerance of oxygen‐sensitive functionalities such as a carbon‐carbon double bond, an organothio group, or a diorganoamino group and the effective preparation of α,β‐unsaturated aldehydes and ketones, resulting from the oxidation of primary and secondary allylic alcohols, since a competitive Heck reaction with the co‐oxidant does not occur. 相似文献
108.
109.
A method to detect obstacle-free paths in real-time which works as part of a cognitive navigation aid system for visually impaired people is proposed. It is based on the analysis of disparity maps obtained from a stereo vision system which is carried by the blind user. The presented detection method consists of a fuzzy logic system that assigns a certainty to be part of a free path to each group of pixels, depending on the parameters of a planar-model fitting. We also present experimental results on different real outdoor scenarios showing that our method is the most reliable in the sense that it minimizes the false positives rate. 相似文献
110.
Antonio Barba-Juan Andrés Mormeneo-Segarra Nuria Vicente Juan Carlos Jarque Carolina Clausell-Terol 《Journal of the American Ceramic Society》2022,105(4):2725-2734
The complex permeability of Cu-doped nickel-zinc polycrystalline ferrites is strongly dependent on microstructure, particularly, on relative density () and average grain size (). In this study, a mathematical model, able to fit the measured magnetic permeability spectra from 106 to 109 Hz, is proposed and validated for a width range of average grain sizes (3.40–23.15 μm) and relative densities (0.83–0.96). To the authors’ knowledge, domain-wall motion and spin rotation contributions to magnetic permeability have been integrated jointly with the microstructure for the first time in the proposed model, highlighting the relative influence of each magnetizing mechanism and microstructure on the magnetic permeability at different angular frequencies. 相似文献