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91.
92.
Chao Chen Bo Feng Shujuan Hu Yue Zhang Song Li Longfei Gao Xuemei Zhang Kun Yu 《Ceramics International》2018,44(1):216-224
Aluminum phosphate (AlPO4) is a promising oxidation-resistant and weak interface for ceramic-matrix composites. In this research, AlPO4 coating was deposited on mullite fibers by an improved liquid-phase method based on electrostatic attraction. A cationic polyelectrolyte, polyethylenimine (PEI), was used for surface modification of mullite fibers. The formation process, phase evolution and microstructure of the coating were studied. The zeta potential of AlPO4 particles, PEI-adsorbed AlPO4 particles, and PEI-adsorbed mullite particles was characterized to find the proper pH value for improving electrostatic attraction. The obtained AlPO4 coating was porous and continuous, whose thickness could be controlled by multiple coating cycles. The relatively low calcination temperature (600 or 1000 °C) was a useful heat treatment method to develop bonding between coating and fiber as well as reduce the fiber strength degradation. The phase transformations of AlPO4 have little volume change, and cristobalite AlPO4 is thermal compatible with mullite. Therefore, the coating structure was preserved after calcining at 1200 °C. The technique is also applicable for other fibers contained mullite phase to fabricate high-performance AlPO4 coated mullite/mullite composites. 相似文献
93.
城区高低层混合居民楼区域作为无线网络覆盖难点,传统宏站无法进行有效的覆盖。本文通过采用“微覆盖、微对打”的建设方式有效解决“高低层混合居民楼”无线网络信号的深度覆盖问题。 相似文献
94.
Based on multiphase field conception and integrated with the idea of vectorvalued phase field, a phase field model for typical allotropic transformation of solid
solution is proposed. The model takes the non-uniform distribution of grain boundaries of
parent phase and crystal orientation into account in proper way, as being illustrated by the
simulation of austenite to ferrite transformation in low carbon steel. It is found that the
misorientation dependent grain boundary mobility shows strong influence on the
formation of ferrite morphology comparing with the weak effect exerted by
misorientation dependent grain boundary energy. The evolution of various types of grain
boundaries are quantitatively characterized in terms of its respective grain boundary
energy dissipation. The simulated ferrite fraction agrees well with the expectation from
phase diagram, which verifies this model. 相似文献
95.
Magdiel Inggrid Setyawati Zhitong Zhao Kee Woei Ng 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(36)
Ingestion of engineered nanomaterials (ENMs) is inevitable due to their widespread utilization in the agrifood industry. Safety evaluation has become pivotal to identify the consequences on human health of exposure to these ingested ENMs. Much of the current understanding of nanotoxicology in the gastrointestinal tract (GIT) is derived from studies utilizing pristine ENMs. In reality, agrifood ENMs interact with their microenvironment, and undergo multiple physicochemical transformations, such as aggregation/agglomeration, dissolution, speciation change, and surface characteristics alteration, across their life cycle from synthesis to consumption. This work sieves out the implications of ENM transformations on their behavior, stability, and reactivity in food and product matrices and through the GIT, in relation to measured toxicological profiles. In particular, a strong emphasis is given to understand the mechanisms through which these transformations can affect ENM induced gut nanotoxicity. 相似文献
96.
Routine reconfiguration is a key challenge for IT-enabled organizational transformation projects. However, how to successfully reconfigure existing routines remains unclear. This case study explores how to achieve routine reconfiguration in IT-enabled organizational transformation and suggests that routine reconfiguration can be achieved through the cross-fertilization of business domain knowledge. We identified a process model of cross-fertilization of business domain knowledge, which essentially incorporates three key processes (i.e., knowledge combination, reflection, and experimentation) and indicates that cross-fertilization can bring changes to all three types of trajectory components. The theoretical and practical implications of this study are also discussed. 相似文献
97.
介绍了山东能源集团财务管理数字化转型的背景,阐述了该集团新型数字化、共享化财务管理模式的建设路径。通过不断探索财务理念和管理实践的创新,以及新型数字化和财务共享管理模式的建设,该集团实现了财务管理模式的转型升级,助力企业实现数字化、智慧化转型。 相似文献
98.
随着宽带的不断增长,用户对运营商的快速支撑能力提出了更高的要求。文章探讨了通过"一户一码"系统建设,将用户宽带和IPTV业务二维码化,通过二维码与固网业务进行绑定,用户业务出现故障需要与装维人员联系咨询的时候,可使用微信等第三方扫码工具扫描家中的业务二维码,进行电话联系咨询、业务查询、故障诊断、一键报障,最终使得用户响应速度和服务效率得到很大提高,取得了非常显著的效果。 相似文献
99.
《Ceramics International》2022,48(4):4401-4423
Nano-zirconia has been widely applied due to its excellent physical and chemical properties (e.g., high strength, corrosion resistance, oxygen ion conductivity). Existing preparation methods of nano-zirconia tend to require long reaction time, and the sizes of final particles are large with uneven distributions. Sub-/supercritical hydrothermal synthesis of nanoparticles is favored by researchers owing to controllable reaction process, uniform particle size distribution, good reproducibility, short reaction time, high conversion rate and harmlessness to environment. In this paper, the characteristics and mechanisms of dissolution, crystallization and growth of nano-zirconia during sub-/supercritical hydrothermal synthesis are systematically reviewed. The influences of process and material parameters on the size and purity of particles are analyzed. Then, the reaction mechanism and product phase transition mechanism during hydrothermal synthesis of zirconia are summarized to provide a theoretical reference for the oriented preparation. Finally, the improvement and commercialization of sub-/supercritical hydrothermal synthesis technology are evaluated, and the future research topics are proposed. 相似文献
100.