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排序方式: 共有2740条查询结果,搜索用时 15 毫秒
1.
Shiming Xie Chen Song Zexin Yu Shaowu Liu Frédéric Lapostolle Didier Klein Chunming Deng Min Liu Hanlin Liao 《Journal of the European Ceramic Society》2021,41(1):535-543
Suspension plasma spraying (SPS) as a potential technique to prepare thermal barrier coatings (TBCs) has been attracting more and more attention. However, most reports on SPS were carried out in the atmosphere. Given the unique features of in-flight particles and plasma jets under low pressure, the resulting coatings are expected to be different from those under atmospheric pressure. In this article, yttria-stabilized zirconia (YSZ) thermal barrier coatings were prepared using suspension plasma spraying under different environmental pressures. The results show that as the environmental pressure decreased, the column-like structural coating turned into a vertical crack segmented structure, as well as a dramatic decrease in surface roughness. More nanoparticle agglomerates were formed in the coating under lower environmental pressures. The real porosity of the coating increased with a decrease in environmental pressure. 相似文献
2.
Lun Feng William G. Fahrenholtz Gregory E. Hilmas Frédéric Monteverde 《Journal of the European Ceramic Society》2021,41(1):92-100
Dense high-entropy (Hf,Zr,Ti,Ta,Nb)B2 ceramics with Nb contents ranging from 0 to 20 at% were produced by a two-step spark plasma sintering process. X-ray diffraction indicated that a single-phase with hexagonal structure was detected in the composition without Nb. In contrast, two phases with the same hexagonal structure, but slightly different lattice parameters were present in compositions containing Nb. The addition of Nb resulted in the presence of a Nb-rich second phase and the amount of the second phase increased as the Nb content increased. The relative densities were all >99.5 %, but decreased from ~100 % to ~99.5 % as the Nb content increased from 0 to 20 at%. The average grain size decreased from 13.9 ± 5.5 μm for the composition without Nb additions to 5.2 ± 2.0 μm for the composition containing 20 at% Nb. The reduction of grain size with increasing Nb content was due to the suppression of grain growth by the Nb-rich second phase. The addition of Nb increased Young’s modulus and Vickers hardness, but decreased shear modulus. While some Nb dissolved into the main phase, a Nb-rich second phase was formed in all Nb-containing compositions. 相似文献
3.
Saint Martin Marie-Judith Orlhac Fanny Akl Pia Khalid Fahad Nioche Christophe Buvat Irène Malhaire Caroline Frouin Frédérique 《Magma (New York, N.Y.)》2021,34(3):355-366
Magnetic Resonance Materials in Physics, Biology and Medicine - Quantitative analysis in MRI is challenging due to variabilities in intensity distributions across patients, acquisitions and... 相似文献
4.
Bataillou Léa Martinelli Laure Desgranges Clara Bosonnet Sophie Ginestar Kevin Miserque Frédéric Wouters Yves Latu-Romain Laurence Pugliara Alessandro Proietti Arnaud Monceau Daniel 《Oxidation of Metals》2020,93(3-4):329-353
Oxidation of Metals - The oxidation of a Ni–30Cr alloy at 700 °C in impure argon was studied in order to provide new elements of understanding on chromia scale growth in low... 相似文献
5.
AbstractThe objective of this study was to compare spray-dried and freeze-dried extracts of Sennae fructus regarding the stability of the sennosides. Therefore, the influence of the addition of maltodextrin (MD) not only before the drying processes but also during fluidized bed granulation was investigated. Analysis of the hygroscopicities, the simultaneous TGA-DSC-MS data, and the influence of storage revealed that spray-dried extracts are more stable than freeze-dried extracts. The addition of MD led to an even better stability of the extracts. Lower amounts of MD are sufficient if applied onto the surface of the native extract during fluidized bed granulation. 相似文献
6.
Florian Weyland Thorsten Eisele Sebastian Steiner Till Frömling George A. Rossetti Jürgen Rödel Nikola Novak 《Journal of the European Ceramic Society》2018,38(2):551-556
The stability of the electrocaloric effect under electric field cycling is an important consideration in the development of solid-state cooling devices. Here we report measurements carried out on Ba(Zr0.2Ti0.8)O3 ceramics which reveal that the adiabatic temperature change, polarization-electric field hysteresis loops and dielectric permittivity/loss show stable behavior up to 105 cycles. We further demonstrate that the loss in electrocaloric response observed after 105 cycles is associated with the migration of oxygen vacancies. As a result, the electrical properties of the material are changed leading to an increase in leakage current and Joule heating. Reversing the polarity of the electric field after every 105 cycles changes the migration direction of oxygen vacancies, thereby preventing charge accumulation at grain boundaries and electrodes. By doing so, the electrocaloric stability is improved and the adiabatic temperature remains constant even after 106 cycles, much higher than achieved in commercially available barium titanate ceramics. 相似文献
7.
Céline Mallet Jérôme Fortin Yves Guéguen Fréric Bouyer 《Mechanics of Time-Dependent Materials》2015,19(2):117-133
We investigate pore fluid effects due to surface energy variation or due to chemical corrosion in cracked glass. Both effects have been documented through experimental tests on cracked borosilicate glass samples. Creep tests have been performed to investigate the slow crack propagation behavior. We compared the dry case (saturated with argon gas), the nonreactive water saturated case (commercial mineralized water), and the distilled and deionized water saturated case (pure water). Chemical corrosion effects have been observed and evidenced from pH and water composition evolution of the pure water. Then, the comparison of the dry case, the mineral water saturated case, and the corrosion case allow to (i) evidence the mechanical effect of the presence of a pore fluid and (ii) show also the chemical effect of a glass dissolution. Both effects enhance subcritical crack propagation. 相似文献
8.
Labussière Mathieu Teulière Céline Bernardin Frédéric Ait-Aider Omar 《International Journal of Computer Vision》2022,130(7):1655-1677
International Journal of Computer Vision - This paper presents a novel calibration algorithm for plenoptic cameras, especially the multi-focus configuration, where several types of micro-lenses are... 相似文献
9.
Journal of Intelligent Manufacturing - Principles of typical motion planning algorithms are investigated and analyzed in this paper. These algorithms include traditional planning algorithms,... 相似文献
10.
Matthias Baldauf Peter Fröhlich 《International journal of human-computer interaction》2014,30(6):446-458
Modern handheld devices can act as “magic lenses” for public displays and enable camera-based real-time interaction with their contents, thus allowing for manifold interactive applications in public space. To learn more about the characteristics of common techniques and to provide guidelines for new ones, a comparative user study was conducted. With regard to two basic task types (selection and translation) and two typical devices (smartphone and tablet), three interaction techniques in-depth were evaluated: direct touch-based input (Touch), cross-hair targeting (Target), and a new technique based on a dynamic cross-hair on the screen that snaps to visible nearby screen objects (Snap Target). The study results indicate that successful interaction with the Touch technique strongly depends on the usage context: Although Touch enables fast selection, it incurs many errors when small targets have to be selected on a smartphone. Target supports such difficult selections better, but Snap Target proved to be most robust in both investigated task types. Also, users stated that they felt best supported by the latter technique. Cross-hair-based techniques, especially Snap Target, were found to be well suitable for scenarios where several device types need to be supported under similar conditions. Implications and further work are discussed. 相似文献