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71.
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《Ceramics International》2022,48(16):23527-23535
Inspired by the surface structure of lotus leaves, micro–nano hierarchical surface structures have been widely used for designing superhydrophobic surfaces. However, the conventionally designed superhydrophobic surface structures are fragile. In this study, a layer of micron-sized mullite whiskers was grown using molten salt on the surface of BaAl2Si2O8 (BAS) glass ceramics. Subsquently, SiO2 nanoparticles modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane were sprayed onto the whisker layer to form a superhydrophobic surface. The nanoparticles exhibit superhydrophobicity, which is protected by the whisker layer containing pores and bulges. This prohibits direct contact between the nanoparticles and external objects. Contact and rolling angle tests indicated that the surface contact angle of the micro–nano hierarchical structure is 158° and the rolling angle is less than 10°. The stability of the superhydrophobic surface was tested through ultraviolet light, long-time immersion in solutions with various pH values, water scouring, and sandpaper abrasion. The results showed that the contact angle is greater than 150°. This study is expected to provide a simple and effective method for fabricating superhydrophobic surfaces on ceramics on a large scale. 相似文献
74.
Jincheng Lin Panpan Lin Run Ao Lili Xing Tiesong Lin Peng He Jian Li Weiqi Yang 《Journal of the European Ceramic Society》2021,41(4):2847-2854
Joining of Y3Al5O12 garnet single crystal (YAG) was achieved by using a bismuth-borate based glass filler. The thermal properties of glass filler were experimentally determined and the wettability of molten glass on YAG was investigated. The YAG reacted with glass to form ZnAl2O4 particles and Y2O3 nanowires successively as joining temperature is above 625℃. ZnAl2O4 preferentially nucleated and grew on Y2O3 nanowires. The cooperative growth of the two phases accelerated YAG decomposition, which in turn led to cluster growth of Y2O3 nanowires and aggregation of ZnAl2O4 particles at elevated temperature. The microstructure evolution and reaction mechanism were studied. The highest shear strength of 29.6 ± 5.2 MPa was obtained for the joint brazed at 650℃. The fracture morphology demonstrated that the dispersive strengthening of ZnAl2O4 and stress relief by Y2O3 nanowire network contributed to the superior mechanical performance. 相似文献
75.
Dapeng Wang Qingzhao Wang Zhiming Wang Huanying Jiang Zhao Zhang Peng Liu Chao Xu Longyang Gao 《Ceramics International》2019,45(9):11578-11583
Glass fibre is a random network structure composed of [SiO4] tetrahedra. The structure contains a large number of defects, which act as crack initiation points. Under tensile stress, cracks undergo crack initiation, stable propagation, failure propagation, and fracture, and the stress that begins after unstable propagation is called the critical fracture stress. When the stress is less than the critical value, the crack is subject to the force of chemical bonds during the crack propagation process, and crack arrest occurs. When the stress is greater than the critical value, the glass fibre will undergo destructive fracture. In this paper, long-term tensile tests were carried out on glass fibre and a glass fibre composite under different constant tensile stress conditions. The fracture times of the glass fibre and glass fibre composite under different tensile stresses were obtained, the critical fracture stress of glass fibre was inferred, and the fracture mechanism was explained. 相似文献
76.
This paper presents a field study of constructing retaining walls using soilbags that are formed by filling the excavated clayey soils into woven bags (geosynthetics). The strength and deformation of the soilbags filled with clayey soils were studied via laboratory tests. A 100?m testing retaining wall was constructed with soilbags in a waterway project. The lateral deformation, the lateral pressures and the surface settlements of the testing retaining wall were monitored during construction and after 7 months operation. The results show that the soilbags can increase the strength of clayey soils. After 7 months of the completion, the lateral deformation and the surface settlement of the testing retaining wall tend to be stable with the maximum values of 29.4?cm and 19.2?cm, respectively. The lateral earth pressure on the front retaining structure could be positively reduced owing to the interlayer's friction of soilbags. Compared to the conventional gravity concrete retaining wall, about 38% construction cost was saved in the 100?m testing retaining wall. 相似文献
77.
Jun Liu Yuhui Zhao Hao Xu Xiaolu Zhao Yutian Tan Peipei Li Dongdong Li Yingmei Tao Dunhua Liu 《International Journal of Food Science & Technology》2021,56(6):3044-3054
The present study aims to examine fruit cell wall-associated fruit softening in Lycium barbarum L. by the microstructure of the fruit cells and the changes in the contents of cell wall components, molecular weights of cell wall polysaccharides and the activities of related cell wall degrading enzymes at different development stages of L. barbarum L. fruit. Fruit firmness significantly declined during ripening, with the greatest reduction between the 28 and 35 days stages. The decrease in firmness correlated with an extensively deformed microstructure in the parenchyma tissues and positively correlated with reductions in the contents of fruit cell wall materials and molecular weight in cell wall polysaccharide. Cellulase, α-galactosidase, polygalactosidase and pectin methylesterase showed higher activities during 28 days; whereas, the activities of β-galactosidase were higher during 35 days. These results indicate that cell wall-related processes are a key feature of early softening in L. barbarum L. 相似文献
78.
With the aim of validating a new standardized Coaxial Double Ring testing procedure, without overpressure and with fixed geometry, an ad hoc theoretical approach has been proposed here to rearrange the laboratory outcomes accounting for the effects of the geometric non-linearities associated with such a testing configuration. By borrowing this idea, once the experimental values of the failure load have been determined, it has been possible to obtain an expression in closed form (fully defined by only two coefficients) of the maximum tensile stress (σmax) in the core of the specimen. Following this, in order to make the laboratory outcomes comparable and homogeneous, the σmax-values have been then re-scaled to a common reference condition (equibiaxial stress on a reference area, σeqbx), by means of the use of a correction coefficient (K) able to determine, under a condition of equal probability of failure, the effective area (Aeff) of the tested specimens. After being corrected to account for the effects of the stress corrosion cracking (static fatigue effect), all re-scaled data have been finally interpreted using a Weibull-type statistical distribution to determine the main fractile values of the glass strength. Doing so, despite some unavoidable approximations, this procedure furnished a highly effective means of determining the bending strength of float glass. Unlike the pure numerical approach proposed in codes and literature, which requires to correct the experimental data via FEM simulation, the rationale behind the proposed approach is in fact to elaborate the experimental data through an analytic treatment of the problem, which would greatly facilitate the interpretation of the data as well as the standardization of the testing procedure. 相似文献
79.
Yong Hou Yu Wang Guo-Hua Zhang Kuo-Chih Chou 《Journal of the European Ceramic Society》2021,41(10):5201-5213
Fully dense and magnetically controllable glass ceramics was successfully synthesized by method of hot pressing using CaO-Al2O3-SiO2-Na2O glass powder and Fe3O4 powder as raw materials. The influences of sintering temperature and time, content and particle size of Fe3O4, as well as particle size of glass powder on the densification and magnetic properties of samples were investigated. It was found that the saturation magnetization gradually increased with increasing magnetite content. In addition, the samples containing smaller size magnetite particles had a higher coercivity. However, for samples using smaller size glass powder, magnetite particles could partially dissolve into the glass matrix, which led to the decrease of saturation magnetization and the increase of coercivity. It was also concluded that the precipitation of crystalline phase from smaller size glass powder caused the decrease of degree of densification, and after decreasing the sintering temperature, the degree of densification of product was enhanced. 相似文献
80.
随着生态环境意识的加强和环保治理力度的提升,平板玻璃窑炉烟气氮氧化物治理已经全面落实。而由于平板显示基板玻璃窑炉烟气性质的独特性,其脱硝技术路线的选择也取决于不同地区氮氧化物排放浓度的限值差异。详细介绍了选择性催化还原法(SCR)、选择性非催化还原法(SNCR)和逆向流选择性催化还原法(CSCR)三种脱硝技术并对比了三者之间在脱硝效率、反应温度、初始投资、全生命周期成本的差异。同时,对未来的发展应用进行了展望。 相似文献