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1.
Zhongchao Fu Xiaodong Li Mu Zhang Qi Zhu Ji-Guang Li Jiao He Xing'an Wang Xudong Sun 《Journal of the American Ceramic Society》2021,104(6):2689-2701
An easy albeit quite effective deionization suspension treatment was adopted to alleviate the detrimental effects related to the hydrolysis of Y2O3 in an aqueous medium. Fabrication of highly transparent Y2O3 ceramics with a fine grain size via air pre-sintering and post–hot isostatic pressing (HIP) treatment without using any sintering additive was achieved using the treated suspensions. The hydrolysis issue of Y2O3 powder in an aqueous medium was effectively alleviated by using deionization treatment, and a well-dispersed suspension with a low concentration of dissolved Y3+ species was obtained. The dispersed suspensions were consolidated by the centrifugal casting method, and the green bodies derived from the suspension of 35.0 vol% solid loading showed an improved homogeneity with a relative density of 52.1%. Fully dense Y2O3 transparent ceramic with high transparency was obtained by pre-sintering consolidated green compacts at a low temperature of 1400°C for 16 h in air followed by a post-HIP treatment at 1550°C for 2 h under 200 MPa pressure. The sample had a fine average grain size of 690 nm. The in-line transmittance of the sample reached 83.3% and 81.8% at 1100 nm and 800 nm, respectively, very close to the theoretical values of Y2O3. 相似文献
2.
Koratagere Revanna Nagaraju Ulavathi Shettar Mahabaleshwar Muddenahalli Siddalinga Prasad Basma Souayeh 《亚洲传热研究》2022,51(6):5288-5301
This article focuses on analytic solutions for Newtonian fluid flow with slip and mass transpiration on a porous stretching sheet using the differential transform method and Pade approximants of an exceptionally nonlinear differential equation. The impacts of different parameters including mass transpiration (suction/injection), Navier's slip, and Darcy number parameters on the velocity of the liquid and tangential stress are discussed. A comprehensive comparison of our results with the previous one in the literature is made, and the results showed good agreement. An investigation is conducted of a combination of magnetic liquids that are conceivably pertinent for wound medicines, skin repair, and astute coatings for natural gadgets. It is found that there is a decrease in the velocity profiles and the boundary layer thickness for the case of suction. 相似文献
3.
为研究不同的滑移情况对圆柱形凹坑织构滑动轴承摩擦力的影响,建立含有圆柱形凹坑织构的滑动轴承在不同界面滑移状态下的摩擦力计算模型,探究影响织构化滑动轴承摩擦力的参数,并借助ANSYS分析不同滑移情况下界面滑移对圆柱形凹坑织构滑动轴承摩擦力的影响规律。结果表明:织构化滑动轴承的摩擦力主要是由轴颈线速度、油膜滑移比、轴承的进出油口压力、织构处油膜压力、织构深度、油膜厚度和承载力决定;不同滑移情况下织构模型的摩擦力均小于无织构模型;且在上下表面均滑移时,圆柱形凹坑织构在出口位置时表现出最优的承载和减摩效果;适当地增加圆柱形凹坑织构的深度可以改善模型的摩擦性能,但是过深的凹坑织构并不能发挥出其性能。 相似文献
4.
为明确准噶尔盆地南缘构造特征,落实中—深层构造圈闭,寻找大型油气田,通过构建二维构造剖面,开展构造变形定量分析,建立了复杂构造模型,厘定了构造活动时间和变形机制。研究表明,南缘经历晚侏罗世和中新世2期变形,晚侏罗世发育走滑断层,形成高泉断隆带、艾卡构造带和齐古—南安集海走滑断裂带,属于准噶尔盆地周缘中生代走滑断裂体系。中新世发育逆冲推覆构造,南缘西段新生代背斜叠加在高泉断隆带、艾卡构造带之上,高探 1 井钻探证实古构造上覆发育的背斜构造是有利的勘探目标。南缘中段发育3排逆冲断层和叠加褶皱,中、下组合是油气勘探重要目标。南缘新生代逆冲推覆构造由南向北扩展,齐古断褶带和盆地深层褶皱形成于中新世初期(23 Ma),霍玛吐断层发生在中新世末期(7 Ma),呼图壁背斜和卡因迪克背斜形成于第四纪。 相似文献
5.
Chia En Liu Wen Chieh Lan Hao Ting Yu Han Lin Yang I. Tseng Liu Hsiao Ping Hsu Chung Wen Lan 《International Journal of Applied Ceramic Technology》2020,17(1):146-152
Silicon kerf loss during wafer slicing and the broken quartz crucibles after silicon casting are two major solid wastes from photovoltaic (PV) industry. Especially, the recycle of kerf-loss silicon has become an urgent issue because near 100 000 t of solid wastes are generated every year. One of the most meaningful recycle routes of the kerf-loss silicon is to make silicon nitride crucibles to replace the quartz crucibles. In this study, we demonstrated how this is feasible through acid leaching refining, slip casting, and nitridation. The reaction-bonded silicon nitride (RBSN) crucibles after oxidation were found pure enough for silicon ingot growth. More importantly, they could be reused after ingot growth. With the present examples, the potential of using the kerf-loss silicon for fine ceramics is prominent. 相似文献
6.
7.
滚动轴承服役过程中,因滚滑现象和残余应力的存在,使赫兹接触应力不能反映材料真实的受力状态,应力分布与实验现象存在一定的偏差,因此滚滑接触下材料的内部应力计算显得尤为重要。研究一种快速、简单的材料滚滑接触内部应力的计算方法,以替代耗时长的有限元法。以现有公式为基础,通过Matlab编程计算滚滑接触下材料内部的应力场;对比不同摩擦因数下2D、3D滚滑接触内部应力场的差别。结果表明:摩擦因数越大,最大剪切应力越大,位置越接近表面,与滚动方向的夹角越小;切向摩擦力使接触点两侧最大正交切应力大小及位置发生变化;随着摩擦因数增大,一侧应力值上升,位置靠近表面,另一侧反之。提出的计算方法简单、方便,其结果为解析解,便于与残余应力或其他应力结合求出真实应力场。通过实例分析发现,真实应力场能够更好地解释实验现象,对于轴承材料组织演变的研究有重要意义。 相似文献
8.
This article investigates the Hall and ion‐slip impacts on the mixed convection flow of a Maxwell nanofluid over an expanding surface in a permeable medium. The impacts of Brownian movement and thermophoresis parameters, Soret, Dufour, viscous dissipation, chemical reaction, and suction parameters, are, moreover, considered. Using the similitude changes, the partial differential equations with regard to the momentum, energy, and concentration equations are transformed to an arrangement of nonlinear ordinary differential equations, which are handled numerically utilizing a spectral relaxation method (SRM). The impacts of noteworthy physical parameters on the velocities, thermal, and concentration distributions are investigated graphically. Moreover, the numerical values of skin‐friction coefficients, local Nusselt number, and Sherwood number for different values of the mixed convection parameter Deborah number Hall parameter ion‐slip parameter Dufour number (Du), and Soret number are computed and tabulated. It is discovered that ascent in Deborah number reduces both the stream and transverse velocity profiles, while the inverse pattern is seen with augmentation in the mixed convection parameter. In addition, inverse patterns of the stream and transverse velocity profiles are seen with expansion in magnetic, Hall, and ion‐slip parameters. Besides this, the temperature and concentration disseminations decline with augmentation in Dufour number and chemical reaction parameters, respectively. It is likewise seen that both the skin‐friction coefficients lessen with expansion in Deborah number, and they ascend with upgrade in blended convection and ion‐slip parameters, while the opposite condition is noticed with augmentation in Hall parameter. Furthermore, the reverse trends of local Nusselt and Sherwood numbers are discovered with expansion in the Dufour and Soret numbers. 相似文献
9.
10.
《Current Opinion in Solid State & Materials Science》2020,24(4):100850
The combination of in-situ and three-dimensional (3D) in transmission electron microscopy (TEM) is one of the emerging topics of recent advanced electron microscopy research. However, to date, there have been only handful examples of in-situ 3D TEM for material deformation dynamics. In this article, firstly, the authors briefly review technical developments in fast tilt-series dataset acquisition, which is a crucial technique for in-situ electron tomography (ET). Secondly, the authors showcase a recent successful example of in-situ specimen-straining and ET system development and its applications to the deformation dynamics of crystalline materials. The system is designed and developed to explore, in real-time and at sub-microscopic levels, the internal behavior of polycrystalline materials subjected to external stresses, and not specifically targeted for atomic resolution (although it may be possible). Technical challenges toward the in-situ ET observation of 3D dislocation dynamics are discussed for commercial structural crystalline materials, including some of the early studies on in-situ ET imaging and 3D modeling of dislocation dynamics. A short summary of standing technical issues and a proposed guideline for further development in the 3D imaging method for dislocation dynamics are then discussed. 相似文献