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1.
《Ceramics International》2022,48(11):15268-15273
SiC/SiC mini-composites reinforced with SiC fibers coated with different numbers of ZrSiO4 sublayers prepared via a non-hydrolytic sol-gel process were fabricated. The tensile strength and work of fracture of the prepared SiC/SiC mini-composites were determined, and the relationship between their mechanical properties and fracture morphologies was discussed. The toughening mechanism and the variation tendency of their mechanical properties were further elaborated by analyzing the interfacial debonding morphologies of the SiC/SiC mini-composites with 1 and 4 layers of ZrSiO4 interphase as well as the results of prior studies. A relatively rare phenomenon—the delamination of the multilayer ZrSiO4 interphase in the SiC/SiC mini-composites but not on the SiC fibers—was observed, which clearly demonstrated the weak bonding between the ZrSiO4 sublayers in the SiC/SiC mini-composites. The ZrSiO4 sublayer delamination mechanism was then explained based on the high-magnification morphologies found in and beside the ZrSiO4 interphase. 相似文献
2.
《Journal of the European Ceramic Society》2021,41(15):7381-7403
Silica-based ceramics have been explored extensively as a class of versatile materials for various applications in architecture, catalysis, energy, machinery, and biomedical engineering. Nevertheless, comprehensive information on silica-based ceramic and electromagnetic microwave (EMW) absorption is scarce, although excellent progress has been made in this field. Here, recent progress in the investigation of silica-based ceramics toward EMW absorption is reviewed. We first introduced the basis of ceramics (characteristics, classification, synthetic methods, potential applications). Subsequently, the silica-based ceramics, including Si-based oxides and alloys, SiOC/SiC/Si3N4/SiCN-based composite, Ti3SiC2 and composite for EMW absorption were systematically summarized. Notably, the fabrication strategies, absorption properties, and mechanisms of silica-based ceramics are described in detail, with a focus on structure and component design. Lastly, the prospects and ongoing challenges of this field in the future are presented. This review is expected to learn from the past and achieve progress toward the future of silica-based ceramic for EMW absorption. 相似文献
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5.
冯鹏一 《信息通信技术与政策》2020,(1):12-15
以电信用户入网协议为切入点,电信用户的携号转网行为应受到《合同法》《消费者权益保护法》等私法规范的保护与限制。该行为引起的格式条款解释、合同终止、违约责任、损失赔偿等问题,不能仅靠《电信条例》等公法规范来调整。应当积极引导广大消费者用户以私法领域相关规定为依据,转变争议解决思维,拓宽纠纷处理途径,合理选择维权手段,以保护自身合法民事权益,与行业监管部门共同推动电信行业有序发展。 相似文献
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Multimedia Tools and Applications - Understanding human emotions through facial expressions is key enabling technology for interactive robots. Most approaches of facial expression recognition are... 相似文献
7.
World Wide Web - In recent years, short text topic modeling has drawn considerable attentions from interdisciplinary researchers. Various customized topic models have been proposed to tackle the... 相似文献
8.
Networks and Spatial Economics - A new comparative framework for estimating the road access of airports around the world at high resolution is proposed. While existing studies are spatially... 相似文献
9.
Recent work has shown that tungsten (W) and other refractory metals with body-centered cubic (bcc) structures exhibit certain novel behavior when their grain size, d, is refined into the ultrafine (UFG, 100 nm < d < 1000 nm) or nanocrystalline (NC, d < 100 nm) regime. For example, it has been shown that bcc refractory metals with such microstructures show decreased strain rate sensitivity besides their elevated strength and vanishing strain hardening response. Consequently, under both quasi-static and high-strain-rate loading, plastic instability in the form of shear banding becomes the dominant mode of plastic deformation. Such behavior is long sought-after in certain applications. However, due to the technology used to refine the grain size (primarily severe plastic deformation), the inability to scale the dimensions of the material may limit wider use and application of UFG/NC bcc refractory metals. In this work, the feasibility was demonstrated of production of large-scale W parts using a diffusion bonding method. The microstructure, preliminary mechanical properties, and issues and challenges associated with the fabrication procedures were examined and discussed. It is envisioned that diffusion bonding may serve as a promising technology for scaled-up fabrication of UFG bcc refractory metals for the targeted application. 相似文献
10.
In service-oriented manufacturing models, manufacturing resources in different enterprises are integrated and shared through network, cloud platforms, and logistics. On cloud manufacturing platforms, service providers offer on-demand manufacturing services to service demanders according to supply-demand matching results. As a special type of manufacturing services, logistics services provide transportation capabilities for production services and demanders. It is a critical issue to schedule logistics services efficiently, especially when manufacturer selections have been planned. This research focuses on the logistics scheduling problem in cloud manufacturing with pre-selected manufacturers. We analyze this optimization problem from aspects of tasks, production services, logistics services, and optimization objectives. Then a logistics scheduling method is proposed to reduce the average delivery time from manufacturers to customers. In the proposed method, the total time from start points of logistics to demanders is considered to reduce the average delivery time of all tasks. Based on four different scenarios, we build their scheduling models and run simulations to verify the effectiveness of the proposed method. Results show that the average task delivery time of the proposed method is shorter than three typical strategies. 相似文献