Influence of whisker-aspect-ratio on densification,microstructure and mechanical properties of Al2O3 whiskers-reinforced CeO2-stabilized ZrO2 composites

A novel composite of 12 mol% CeO₂-stablized tetragonal ZrO₂ reinforced with Al₂O₃ whiskers (designated as Ce-TZP/A_w) has been prepared and studied in this work. The objective of this investigation was to systematically study the influence of whisker-aspect-ratio on the densification behaviors, microstructure evolution, and mechanical properties of Ce-TZP/A_w composite. Results showed that the sintered density of composite increased and the grain growth tended to diminish with the decrease in whisker aspect radio. Both the fracture toughness and flexural strength reached maximum values of 475 ± 12 MPa and 11.4 ± 0.2 MPa m^1/2, respectively at a whisker aspect ratio of about 12. It was also observed that the fracture toughness, flexural strength and tetragonal to monoclinic ZrO₂ transformation of the dual-phase composite exhibited similar variation trend as a function of the whisker-aspect-ratio, which suggested that the stress-induced phase transformation should be the main toughening and strengthening mechanism in the Ce-TZP/A_w composite.     

新一代信息基础设施推动能源发展的路径安排和绩效研究

随着信息技术的迅猛发展,其带来的变革浪潮涌动在各个角落。作为社会的运行动脉,能源的产生运转和利用体系享受新一代信息基础设施的优势,发生着巨大变化。文章研究了新一代信息基础设施对于能源革命的推动传导方式的影响,分析了在这一过程中新一代信息基础设施普及对能源行业及能源使用方式的影响。基于过往信息化数据、已有理论及当下流行的5G运用方式,做回溯性探究,前瞻未来能源革命的蓝图。     

Enriching Context Information for Entity Linking with Web Data

Journal of Computer Science and Technology - Entity linking (EL) is the task of determining the identity of textual entity mentions given a predefined knowledge base (KB). Plenty of existing...     

Fabrication of antifouling membranes by blending poly(vinylidene fluoride) with cationic polyionic liquid

Membrane fouling problem is now limiting the rapid development of membrane technology. A newly synthesized cationic polyionic liquid (PIL) [P(PEGMA-co-BVIm-Br)] was blended with poly(vinylidene fluoride) (PVDF) to prepare antifouling PVDF membranes. The PVDF/P(PEGMA-co-BVIm-Br) exhibited an increased surface hydrophilicity, the water contact angle was reduced from 77.8° (pristine PVDF) to 57.9°. More porous membrane structure was obtained by adding PIL into the blending polymers, as high as 478.0 L/m²·h of pure water flux was detected for the blend PVDF membrane in comparison with pristine PVDF (17.2 L/m²·h). Blending of the cationic PIL with PVDF gave a more positive surface charge than pristine PVDF membrane. Blend membranes showed very high rejection rate (99.1%) and flux recovery rate (FRR, 83.0%) to the positive bovine serum albumin (BSA), due to the electrostatic repulsion between the membrane surface and proteins. After three repeated filtration cycles of positive BSA, the blend PVDF membranes demonstrated excellent antifouling performance, the permeation flux of the membranes was recovered very well after a simple deionized water washing, and as high as 70% of FRR was obtained, the water flux was maintained at above 350 L/m²·h. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48878.     

Synthesis and experimental study of novel double perovskite Ba2NixCo2−xO6 as promising oxygen carrier materials for CO2 capture application

Novel oxygen-deficient double-perovskite type oxide Ba₂Ni_xCo_2−xO₆ was applied to produce O₂/CO₂ mixed stream gas for oxyfuel combustion application. A series of different Co concentration substituted Ba₂Ni_xCo_2−xO₆ was synthesized by an EDTA-citrate sol-gel combustion method. The oxygen carriers, Ba₂Ni_0.25Co_1.75O_6, Ba₂Ni_0.45Co_1.55O₆, Ba₂Ni_0.65Co_1.35O₆ and Ba₂Ni_0.85Co_1.15O₆ were c\characterized by scanning electron microscopy and cyclic oxygen adsorption/desorption experiments. The results showed that the capacity of provided O₂ was improved by the partial substitution of Ni by Co. In addition, the synthesized perovskites exhibit good regeneration ability. The optimal degree of Co substitution was x = 0.25 for Ba₂Ni_xCo_2−xO₆ with consideration of oxygen desorption ability. Therefore, Ba₂Ni_0.25Co_1.75O₆ was selected to examine the influence of the operating parameters on the oxygen release performance. It was found that the desorption temperature and CO₂ partial pressure are the two main operating parameters for the oxygen desorption performance. Further, the proposed novel double perovskite Ba₂Ni_0.25Co_1.75O₆ provided excellent performance, the O₂ production of Ba₂Ni_0.25Co_1.75O₆ can still reach 120 mg/g after 10 cycles.     

Toward high performance solid-state lithium-ion battery with a promising PEO/PPC blend solid polymer electrolyte

A promising solid polymer blend electrolyte is prepared by blending of poly(ethylene oxide) (PEO) with different content of amorphous poly(propylene carbonate) (PPC), in which the amorphous property of PPC is utilized to enhance the amorphous/free phase of solid polymer electrolyte, so as to achieve the purpose of modifying PEO-based solid polymer electrolyte. It indicates that the blending of PEO with PPC can effectively reduce the crystallization and increase the ion conductivity and electrochemical stability window of solid polymer electrolyte. When the content of PPC reaches 50%, the ionic conductivity reaches the maximum, which is 2.04 × 10⁻⁵ S cm⁻¹ and 2.82 × 10⁻⁴ S cm⁻¹ at 25°C and 60°C, respectively. The electrochemical stability window increases from 4.25 to 4.9 V and the interfacial stability of lithium metal anode is also greatly improved. The solid-state LiFePO₄//Li battery with the PEO/50%PPC blend solid polymer electrolyte has good cycling stability, which the maximum discharge specific capacity is up to 125 mAh g⁻¹ at a charge/discharge current density of 0.5 C at 60°C.     

核电主管道锻件心部裂纹缺陷性质分析

核电主管道锻造毛坯在中心棒套料加工过程中发现中心棒的一段出现裂纹,并伴有大量碎块。对中心棒及碎块金属进行化学成分分析、低倍、高倍检验和能谱分析,并采用Jmatpro对316LN钢平衡析出相进行了计算。结果表明,裂纹区域存在的大量条状和粒状α-Cr析出相导致局部塑性降低,变形不协调,在锻造过程中形成了裂纹。     

亚稳β型TRIP/TWIP钛合金研究进展

综述了当前国内外学者关于具有相变诱发塑性/孪晶诱发塑性(transformation induced plasticity/twinning induced plasticity,TWIP/TRIP)效应的亚稳β型钛合金的研究进展。介绍了该类钛合金的设计方法。统计了近几年开发的TWIP/TRIP钛合金家族成员及其力学性能,归纳了合金在塑性变形过程中的变形产物及其形成机制,指出了该类钛合金在发展过程中遇到的一些问题。