H.T.Cao
金属学报(英文版)
Al and Mn co-doped-ZnO films have been prepared at room temperature by DC reactive magnetron sputtering technique. The optical absorption coefficient, apparent and fundamental band gap, and work function of the films have been investigated using optical spectroscopy, band structure analyses and ultraviolet photoelectron spectroscopy (UPS). ZnO films have direct allowed transition band structure, which has been confirmed by the character of the optical absorption coefficient. The apparent band gap has been found directly proportional to N^2/3, showing that the effect of Burstein-Moss shift on the band gap variations dominates over the many-body effect. With only standard cleaning protocols, the work function of ZnO: (Al, Mn) and ZnO: Al films have been measured to be 4.26 and 4.21eV, respectively. The incorporation of Mn element into the matrix of ZnO, as a relatively deepd onor, can remove some electrons from the conduction band and deplete the density of occupied states at the Fermi energy, which causes a loss in measured photoemission intensity and an increase in the su,rface work function. Based on the band gap and work function results, the energy band diagram of the ZnO: (Al, Mn) film near its surface is also given.
关键词:
transparent conducting oxide film
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边雪
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吴文远
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常宏涛
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杨眉
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孙树臣
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涂赣峰
稀土
doi:10.3969/j.issn.1004-0277.2007.05.006
利用有机三元弱酸(柠檬酸)与金属阳离子的配位作用促进包头矿CaO焙烧产物中磷元素的溶解,研究采用盐酸(HCl)-柠檬酸(H3cit)低酸度混合酸酸洗包头矿CaO焙烧产物.通过正交回归试验研究了盐酸浓度、柠檬酸浓度、温度、液固比、时间、搅拌速度对焙烧产物脱磷率的影响,得到了相应的二次回归方程.试验研究确定了最优的脱磷的条件:盐酸浓度为0.5mol·L-1,柠檬酸浓度为0.05mol·L-1,温度为室温,液固比为10∶1,时间为20min,搅拌速度为250转/min,脱磷率为99.5%.
关键词:
包头矿
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脱磷
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柠檬酸
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正交回归实验
井敏
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谭婷婷
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王成国
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冯志海
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杨云华
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潘月秀
材料科学与工艺
doi:10.11951/j.issn.1005-0299.20150208
东丽T800H和T800S是分别采用湿纺和干湿纺制备的两种力学性能相近的碳纤维，为弄清不同纺丝方法对T800级碳纤维微观结构的影响，采用扫描电镜、X射线衍射仪、小角X射线散射仪和高分辨透射电镜对这两种碳纤维进行测试，比较其表面形貌、断口形状和形貌、石墨微晶结构和微孔结构等．研究结果表明，湿纺制备的T800H比干喷湿纺制备的T800S的表面粗糙、断口圆度差、原纤尺寸较大、石墨微晶致密度差且发育不完善、内部微孔尺寸大、石墨微晶条带韧性差，这正是T800H的拉伸强度和断裂伸长率不如T800S的重要微观结构因素，但T800H的石墨微晶取向度不如T800S，孔隙率略高于T800S．
关键词:
碳纤维
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微观结构
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力学性能
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表面形貌
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孔结构
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石墨微晶
王迎芬
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彭公秋
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李国丽
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谢富原
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刘勇
材料科学与工艺
doi:10.11951/j.issn.1005-0299.20150420
为了研究T800H碳纤维的表面特性及其与BA9918树脂的界面匹配性，分别采用SEM、AFM、XPS和TGA对T800H碳纤维表面形貌、表面化学特性以及碳纤维上浆剂热稳定性进行表征，测试了T800H／BA9918复合材料湿热处理前后0°压缩强度、90°拉伸强度和层间剪切强度，并得到了其在湿热处理前后的开孔压缩和冲击后压缩性能。测试发现T800H碳纤维表面有明显的沟槽，有利于表面机械啮合作用；T800H／BA9918复合材料经29 J能量冲击后压缩强度为314 MPa；在130℃湿态环境下其0°压缩强度和层间剪切强度保持率高于58％，开孔压缩强度保持率高于60％。试验结果证明T800H碳纤维与BA9918树脂具有良好的界面匹配性，T800H／BA9918复合材料具有优异的耐湿热性能。
关键词:
T800H碳纤维
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复合材料
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力学性能
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湿热处理
李新梅
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张忠文
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邹勇
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杜宝帅
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邹增大
材料导报
根据新型耐热钢T92和Super304H钢的焊接特点制定了适宜的焊接工艺,研究了焊制的T92/Super304H异种钢焊接接头的力学性能.结果表明,T92/Super304H异种钢接头的各项力学性均能满足使用要求.焊缝金属的韧性远低于T92钢侧热影响区,焊缝金属的结晶形态对焊缝韧性有很大的影响.焊接接头中焊缝金属的硬度值最高,而T92钢侧热影响区硬度最低,并且不同热影响区部位显微硬度变化较大,Super304H钢侧热影响区硬度变化不大.
关键词:
T92钢
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Super304H钢
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新型耐热钢
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异种钢
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焊接接头
徐元森
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邹元爔
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刘辅链
金属学报
利用CaF_2的高溫水解反应平衡,測定了1450℃时CaO-CaF_2系和CaO-SiO_2-CaF_2系熔渣中CaO对CaF_2的活度比,并按变通的Gibbs-Duhem方程式計算了二元系中CaO及CaF_2的活度和三元系中SiO_2的活度。試驗結果表明,将CaF_2視为中性,而用簡单的CaO/SiO_2比表示含氟高炉渣的碱度是合理的。从三元系中等SiO_2活度线可以看出提高碱度可大大降低SiO_2的活度,因而可以对渣中氧化硅的还原和氟的揮发起有效的抑制作用。
关键词:
Huijie LIU
材料科学技术（英文）
The friction stir weldabilities of the strain-hardened AA1050-H24 and precipitate-hardened AA6061-T6 aluminum alloys were examined to reveal the effects of material properties on the friction stir welding behavior. The experimental results are obtlained. (1) For AA1050-H24, the weld can possess smoother surface ripples; there is no elliptical weld nugget in the weld; there is no discernible interface between the stir zone and the thermomechanically affected zone; and the internal defect of the weld looks like a long crack and is located in the lower part of the weld. (2) For AA6061-T6, the weld usually possesses slightly rougher surface ripples; an elliptical weld nugget clearly exists in the weld; there are discernible interfaces among the weld nugget, thermomechanically affected zone and heat affected zone; and the internal defect of the weld is similar to that of the AA1050-H24 weld. (3) The effective range of welding parameters for AA1050-H24 is narrow, while the one for AA6061-T6 is very wide. (4) The maximum tensile strength efficiency of the AA1050-H24 joints is similar to that of the AA6061-T6 joints, i.e. 79% and 77%, respectively.
关键词:
Friction stir weldability
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