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to the microstructure evolution during the heat treatment. Key words: Cu-4Cr-2Nb alloy; coating; cold spraying; vacuum heat treatment; microstructure; microhardness 1 Introduction Continuous efforts are under... it an attractive alternative to other current high temperature Cu based alloys. The commonly used fabrication processes include casting, forging, and heat treatment[1]. These alloys can also be direct......
Preparation of poly(propylene carbonate)/organophilic rectorite nanocomposites via direct melt intercalation WAN Chun-jie(万春杰)1,2, YU Jian-ying (余剑英)1, SHI Xiao-jian (石小建)1, HUANG Li-hua (黄丽华)1 1.College of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; 2.School of Chemical Engineering and Pharmacy, Wuhan Institute of Chemical Technology......
with a withdrawal rate of 6 mm/min. Conventional helical starters were utilized to initiate single crystal growth. The full heat treatment schedules for the two alloys were (1 335 °C, 16 h)+(1 345 °C, 16 h, air cooling)+(1 100 °C, 4 h, air cooling)+(870 °C, 24 h, air cooling) and (1 325 °C, 16 h+1 335 °C, 16 h, air cooling)+(1 100 °C, 4 h, air cooling)+(870 °C, 24 h, air cooling), respectively. 2.2......
contributes to the refinement of solidified grains. Key words: superalloy; grain refinement; low voltage pulsed magnetic field; cooling rate; superheating 1 Introduction Grain refinement is an effective method to improve the deformability and mechanical properties of superalloy. Fine grain casting of superalloy mainly includes the thermal control method [1], the chemical approach [2-3......
; whisker; oxidation; crystal growth 1 Introduction Zinc oxide (ZnO), an exceptionally important semiconductor with wide gap energy (3.37 eV), large exciton banding energy (60 meV) at room temperature, high mechanical and thermal stabilities, exhibits excellent properties in piezoelectricity [1] and optics [2]. ZnO nanostructure has aroused much interest due to its promising applications in laser......
: severe plastic deformation; cyclic extrusion compression; corrosion behavior; mechanical properties; hydrostatic pressure 1 Introduction Magnesium alloys are normally combinations of magnesium with other... structure such as aluminum. The major application of the magnesium cast alloys is nowadays in automotive industry [1], and biomedical application [2]. However, their poor corrosion behaviors and lower......
各种方法的特点,提出发展绿色,高选择性合成方法制备单分散结构可控的金属氧化物半导体纳米晶仍是今后重要的研究方向之一. 关键词:金属氧化物半导体；纳米晶；液相合成；形貌；晶型 中图分类号:O782+1 文献标志码:A Recent advances of controlled synthesis of metal oxide...非常重要的物理和化学性质的宽禁带金属氧化物,它们的纳米晶展现出不同于常规状态下的光电转换,气敏,和光学性质,在染料敏化太阳能电池,光电子器件,新型气敏材料,抗静电复合材料,耐磨材料和催化材料,固体电解质电池,功能涂层等领域具有广泛的应用[1].氧化物半导体纳米晶的性质和应用取决于其晶型,形貌,大小和结晶度(缺陷)等关键因素[2].实现微观结构调控可以更深入地研究金属氧化物半导体纳米晶微观结构和性能......
for the highest photocatalytic activity of ZnO/ZnS/α-Fe2O3. Key words: nanocomposite; ZnO; ZnS; α-Fe2O3; calcination; optical properties; photocatalytic activity 1 Introduction With the development of industry and economy, environmental problems have become more and more vigorous in recent years [1]. Organic contaminants, which are resistant to environmental degradation, thus capable of remaining......
调变面临的挑战和发展方向进行了展望. 1 非晶态催化剂的特性 非晶态催化剂由于具有两个显著的特点,即短程有序和长程无序,导致在原子水平上以有序结构的状态随机堆积,从而在三维空间上呈现拓扑无序排列的形式[14-15],因此,与晶体型催化剂相比,非晶态催化剂在相同质量下包含更大的比表面积和结构缺陷,使其在催化反应中具有丰富的活性位[16-17].这种非平衡的亚稳态结构增强了非晶态催化剂的灵...Tafel斜率低至34 mV/dec,电流密度达到1 mA/cm2和10 mA/cm2时所需过电位可减少50 mV,仅为190 mV和220 mV,并在反应中保持良好的稳定性.SALIMI等[21]通过电化学法在金属Ir表面原位形成了非晶态IrOx.该催化剂具有较大的电化学比表面,催化OER的活性远高于晶态IrOx.TSUJI等[22]利用电沉积和射频磁控溅射在FTO基板上制备了RuO2薄膜并调节退火温......
; 1 Introduction Continuous flow, stirred-tank based biooxidation processes... than 1 g/L to 13 g/L. Unfortunately, no samples of the early biooxidation bacterial consortium were maintained and therefore it was not possible to compare the bacteria in the original arsenic......
