Recently, nanostructured thermal barrier coatings have received considerable attention because of some superior properties in comparison with their conventional counterpart. In this study, nanostructured 8 wt% yttria-stabilized zirconia (n-YSZ) coatings were deposited by atmospheric plasma spraying, and the degradation behavior caused by molten calcium-magnesium-aluminon-silicate (CMAS) attack was investigated. Results showed that the thermo-chemical reaction product between CMAS and YSZ (both powders and coatings) is different with the change of CMAS content. At low CMAS concentration, a cubic phase is generated by the diffusion of Ca into YSZ grains. As compared to the conventional YSZ, less C-ZrO2 is detected for n-YSZ. When CMAS reaches a certain concentration (eg 15 mg/cm2), disruptive phase transformation from tetragonal to monoclinic will occur and the reaction is more readily for n-YSZ. Two different chemical reaction mechanisms governing the CMAS content effect were proposed. It should be noted that the nanozone in the coatings plays an important role in the CMAS degradation process, which enhances CMAS infiltration rate and accelerates the chemical reaction, leading to a poor CMAS resistance of the nanostructured coating than that of the conventional counterpart. 相似文献
The structural characteristics, pasting and rheological behaviours of cassava starch before and after pregelatinisation were determined by various modern analysis techniques. Pregelatinisation, especially in an ultrasonic environment, can disrupt the granule structure, crystalline structure and short‐range ordered molecular structure of cassava starch. Compared with native starch, pregelatinisation had significantly decreased viscosities and weakened gel structures of starch pastes. Not only did native and pregelatinised starch pastes exhibit shear‐thinning behaviours but also the pregelatinised treatment resulted in the formation of weak gel structures. This study enabled us to acquire the desired pasting and rheological properties of pregelatinised starch by modulating its hierarchical structural changes. 相似文献
Convolutional network (ConvNet) has been shown to be able to increase the depth as well as improve performance. Deep net, however, is not perfect yet because of vanishing/exploding gradients and some weights avoid learning anything during the training. To avoid this, can we just keep the depth shallow and simply make network wide enough to achieve a similar or better performance? To answer this question, we empirically investigate the architecture of popular ConvNet models and try to widen the network enough in the fixed depth. Following this method, we carefully design a shallow and wide ConvNet configured with fractional max-pooling operation with a reasonable number of parameters. Based on our technical approach, we achieve 6.43% test error on CIFAR-10 classification dataset. At the same time, optimal performances are also achieved on benchmark datasets MNIST (0.25% test error) and CIFAR-100 (25.79% test error) compared with related methods.
Fiber‐based supercapacitors (FSCs) possess great potential as an ideal type of power source for future weaveable/wearable electronics and electronic‐textiles. The performance of FSCs is, without doubt, primarily determined by the properties of fibrous electrodes. Carbonaceous fibers, e.g., commercial carbon fibers, newly developed graphene fibers, and carbon nanotube fibers, are deemed as promising materials for weaveable/wearable supercapacitors owing to their exotic properties including high tensile strength and robustness, excellent electrical conductivity, good flexibility, and environmental stability. Nevertheless, bare carbonaceous fiber normally exhibits low capacitance originating from electric double‐layer capacitance, which remains unsatisfactory for efficiently powering wearable and portable devices. Numerous efforts have been devoted to tailoring fiber properties by hybridizing pseudocapacitive materials, and impressive progress has been achieved thus far. Herein, the microstructures of pristine carbonaceous fibers are introduced in detail, and the recent advances in rational nano/microstructure design of their hybrids, which provides the feasibility to achieve the synergistic interaction between conductive agents and pseudocapacitive nanomaterials but are normally overlooked, are comprehensively reviewed. Besides, the challenges in developing high‐performance fibrous electrodes are also elaborately discussed. 相似文献