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161.
摘要将燃烧合成技术与传统焊接技术相结合,以Ti-Ni体系为连接材料研究了08钢/1Cr18Ni9不锈钢焊接焊缝的形成过程,探索了Ti-Ni加压燃烧合成的过程及产物的形成机制,焊缝与基体的结合行为。目的在于开发出一种新型层状金属复合材料的制备工艺。 相似文献
162.
介绍了2002年国内高碳铬轴承钢的产量及品种结构,评述了国内轴承钢生产工艺装备、质量状况和发展方向。 相似文献
163.
164.
Yan Cui Zequan Zeng Jianfeng Zheng Zhanggen Huang Jieyang Yang 《Frontiers of Chemical Science and Engineering》2021,15(5):1125
To realize the utilization of visible light and improve the photocatalytic efficiency of organic pollutant degradation in wastewater, a nitrogen-doped titanium-carbon composite (N-TiO2/AC) prepared by sol-gel methods was applied in the photodegradation of phenol assisted by persulfate under visible light irradiation (named N-TiO2/AC/PS/VIS). The results show that a synergistic effect exists between visible-light photocatalysis and persulfate activation. Compared with TiO2/PS/VIS, the phenol degradation rate was found to be observably improved by 65% in the N-TiO2/AC/PS/VIS system. This significant increase in degradation rate was mainly attributed to the following two factors: 1) The N and C doping can change the crystal structure of TiO2, which extends the TiO2 absorption wavelength range to the visible light region. 2) As an electron acceptor, PS can not only prevent electrons and holes from recombining with each other but can also generate strong oxidizing radicals such as ∙SO4– and ∙OH to accelerate the reaction dynamics. The process of phenol degradation was found to be consistent with the Langmuir pseudo-first-order kinetic model with an apparent rate constant k of 1.73 min–1. The N-TiO2/AC/PS/VIS process was proven to be a facile method for pollutant degradation with high pH adaptability, excellent visible-light utilization and good application prospects. 相似文献
165.
Junpeng Xiong Weili Shao Ling Wang Chen Cui Yurui Jin Hongqin Yu Pengju Han Yanfei Gao Fan Liu Qingqing Ni Jianxin He 《大分子材料与工程》2021,306(11):2100371
Recently, because of the outbreak of COVID-19, the demand for various types of filter elements in protective materials has increased globally. Furthermore, new requirements for the filtration performance of PM2.5 liquid (oil) particles have been put forward. In this work, Superhydrophobic and superoleophobic composite nanofibers with excellent filtration capacity for oil and salt particles are developed through the modification of polyacrylonitrile (PAN) by fluoro-polyurethane (FPU) doping. The results show that the PAN/FPU composite nanofibers doped with 9 wt% FPU has a uniform fiber morphology with a diameter of 240 ± 30 nm. Compared to the pure PAN nanofibers, the water-based contact angle of PAN/FPU increases from 90 ± 5° to 151 ± 5°, and the oil-based contact angle increases from 58 ± 2° to 152 ± 3°. Importantly, at a high flow rate of 95 L min−1, the filtration efficiency of the PAN/FPU nanofiber membrane for 0.3 µm oil particles increases from 92 ± 1% to 99.2 ± 0.1%. After cyclic loading, the filtration efficiency of 0.3 µm oil particles remains above 98%. Meanwhile, the filtration efficiency for 0.3 µm salt particles remains at 98.23 ± 0.1%. The PAN/FPU nanofiber membrane developed in this work is effective in applications and has good market prospects as a protective filtration material. 相似文献
166.
Yang Zhu Xiangli Meng Qiang Zhang Liansheng Yan Hong Cui 《International Journal of Applied Ceramic Technology》2021,18(4):1330-1341
A 3D architecture carbon fiber preform, specifically fine-woven cloth and punctured felt preform, is used to manufacture a novel advanced Cf/C-SiC-ZrC composite. The composite matrix is produced by chemical vapor infiltration (CVI) plus precursor infiltration and pyrolysis (PIP) process and finalized by using a chemical vapor deposition (CVD) of SiC coating to make the final density of the material reach 1.95 g/cm3. The organic precursors of SiC and ZrC have a weight ratio of 4:1 in a xylene solute. The composite mechanical properties, such as tensile, compression, bending, shear, and Z-direction load bearing, are introduced under analysis to find possible applications for the composite. What is more, scanning electron microscope (SEM) images are employed to illustrate the failure behavior of the ceramic composite. The results showed that the punctured filament tows will be beneficial, not only for the composite to withstand compression force up to 308.6 MPa and shear strength to 18.14 MPa but also for the alternatively stacked weave piles and short fiber layers to support the punctured bundles, as well as to hold the composite structure under mechanical forces from different orientations, which is believed to reinforce the ceramic matrix for some high pressure and severe ablation applications. 相似文献
167.
Computational modeling of cathodic limitations on localized corrosion of wetted SS 316L at room temperature 总被引:1,自引:0,他引:1
The ability of a SS 316L surface wetted with a thin electrolyte layer to serve as an effective cathode for an active localized corrosion site was studied computationally. The dependence of the total net cathodic current, Inet, supplied at the repassivation potential Erp (of the anodic crevice) on relevant physical parameters including water layer thickness (WL), chloride concentration ([Cl−]) and length of cathode (Lc) were investigated using a three-level, full factorial design. The effects of kinetic parameters including the exchange current density (io,c) and Tafel slope (βc) of oxygen reduction, the anodic passive current density (ip) (on the cathodic surface), and Erp were studied as well using three-level full factorial designs of [Cl−] and Lc with a fixed WL of 25 μm. The study found that all the three parameters WL, [Cl−] and Lc as well as the interactions of Lc × WL and Lc × [Cl−] had significant impact on Inet. A five-factor regression equation was obtained which fits the computation results reasonably well, but demonstrated that interactions are more complicated than can be explained with a simple linear model. Significant effects on Inet were found upon varying either io,c, βc, or Erp, whereas ip in the studied range was found to have little impact. It was observed that Inet asymptotically approached maximum values (Imax) when Lc increased to critical minimum values. Imax can be used to determine the stability of coupled localized corrosion and the critical Lc provides important information for experimental design and corrosion protection. 相似文献
168.
针对某黄金生产企业含砷氰化尾矿污染特征,开展了搅拌洗涤法、臭氧氧化法、酸化溶砷法、铁盐固砷法等多种无害化方法联合处理试验研究,旨在将该含砷氰化尾矿处理至满足氰渣规范回填利用污染控制要求。结果表明:该含砷氰化尾矿回填利用污染控制技术工艺为压滤调浆搅拌洗涤+臭氧氧化+酸化溶砷+铁盐固砷,最佳参数为原矿浆压滤后加水调浆,矿浆浓度40%,臭氧投加量0.66 g/L,酸化溶砷pH值3、曝气量0.1 m3/h、反应时间2 h,铁盐固砷七水合硫酸亚铁投加量20.0 g/L、反应时间1 h。研究结果为该黄金生产企业含砷氰化尾矿回填利用提供了技术支撑。 相似文献
169.
静磁场对ZK60镁合金组织的影响 总被引:4,自引:1,他引:4
试验发现在镁合金的凝固过程中施加静态磁场能有效细化晶粒,减小晶界化合物的厚度,同时,出现了大量细小块状化合物,这有利于提高镁合金的成形性能。 相似文献
170.
Research and Applications of Semi-solid Processing 总被引:1,自引:0,他引:1
Since it was pioneered by Flemings and otherresearchers [11, the semi-solid metal processingtechnique has been widely stUdied in the world.Especially in the past decade, SSM as a newproduct forming technique has been rapidly developed and put into commercial applications[2, 31. In recent years, with the development ofthe ado-industry of China, a lot of researchwork on SSM has been done, including the preparation of slumes, reheating and thixoforming[Al6]; moreover, great achievements have … 相似文献