共搜索到689条信息,每页显示10条信息,共69页。用时:0小时0分0秒187毫秒
-addition steels after unidirectional solidification were examined using field emission scanning electron microscope (FE-SEM) and electron probe X-ray microanalyzer (EPMA). In such specimens, dendrite...) precipita- tion because of microsegregation. The effect of cooling rate on (Ti, Nb)(C, N) precipitation was investigated. The composition of large precipitates was determined using FE-SEM with EDS......
), field-emission scanning electron microscopy (FE-SEM), en- ergy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). FE-SEM images......
electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Various heat treatment temperatures (850, 900, 950, 1000 and 1050℃) were used to obtain glass-ceramics of the ideal wollastonite crystal phase as well as optimum mechanical properties and chemical durability. From XRD, FE-SEM and EDS, the crystallization of acicular crystal phase in the matrix was achieved at heat treatment......
-ray powder diffraction(XRD) and field emission scanning electron microscopy(FE-SEM) were utilized to characterize the crystal structure and morphology. The emission and excited spectra were used to study the photoluminescence properties. The results of XRD and FE-SEM indicated that the samples prepared by this method were pure phase and the particle size was about 50 nm. The PL results showed......
-addition steels after unidirectional solidification were examined using field emission scanning electron microscope (FE-SEM) and electron probe X-ray microanalyzer (EPMA). In such specimens, dendrite...) precipita- tion because of microsegregation. The effect of cooling rate on (Ti, Nb)(C, N) precipitation was investigated. The composition of large precipitates was determined using FE-SEM with EDS......
水热法制备菜花状氧化锌 刘长友1,介万奇1,李焕勇1 (1.西北工业大学,材料学院,陕西,西安,710072) 摘要:以Zn(NO3)2·6H2O和N2 H4·H2O为原料,采用水热法在180℃制备了菜花状的氧化锌(ZnO)纳米棒束,不规则的长短棒晶须体以及柱状晶须束.用XRD,SEM,FE-SEM及HR-TEM对样品进行了表征.具有六方纤维锌矿结构的ZnO棒或柱的直径分别在100,200nm和1μm左右.以负离子配位多面体生长基元理论讨论了ZnO晶体的生长过程及N2H4·H2O浓度对ZnO形貌的影响. 关键词:氧化锌; 水热法; 纳米棒; 晶须; 结构与形貌; [全文内容正在添加中] ......
核壳结构的氧化锆包裹氧化铝纳米复合粉体的制备研究 俞建长1 (1.福州大学材料学院,福州,350002) 摘要:采用简单的一步醇盐水解包裹工艺在市售纳米氧化铝颗粒表面均匀地包裹了一层厚度为4~5nm的纳米晶氧化锆,形成核壳结构的氧化物纳米复合粉体.通过简单的锆源及酸浓度的控制,可以实现包裹的氧化锆层厚度的可控调节.借助XRD,TEM,FE-SEM及EDS等测试手段对合成的材料进行了形貌与结构表征,结果表明这种纳米氧化锆包裹氧化铝的核壳复合结构材料,可以有效地抑制氧化铝在高温煅烧下的晶粒过分长大,实现在较低煅烧温度下即具有均匀致密的表面形貌. 关键词:核壳结构; 醇盐水解; 氧化锆包裹氧化铝; [全文内容正在添加中] ......
Sol-Gel法制备Bi2WO6薄膜及其可见光诱导降解RhB(英文)宋丽花,谈国强,任慧君,尹君,夏傲陕西科技大学 教育部轻化工助剂化学与技术重点实验室摘 要:以Na2WO4.5H2O和Bi(NO3)3.5H2O为原料,乙二醇甲醚溶剂,柠檬酸和乙酰丙酮为添加剂,采用sol-gel法在FTO基板上成功制备了Bi2WO6薄膜.利用XRD,FE-SEM,DRS,PL等分析手段Bi2WO6薄膜进行表征和性能测试.结果表明随着退火时间减少,由sol-gel法制备的Bi2WO6薄膜XRD最强峰和次强峰的强度比发生了变化.所制备的薄膜厚度为180nm,表面形貌均匀且多孔,在紫外-可见光均有吸收,可见光区有几个光致发光发射峰.在可见光照射下,Bi2WO6薄膜可以缓慢的降解RhB.关键词:Bi2WO6;薄......
TiO2纳米管阵列薄膜的热稳定性蒋武锋,郝素菊,苍大强,凌云汉,白新德摘 要:采用液相沉积法在Al板上制备了TiO2纳米管阵列薄膜,并在不同温度下进行了热处理.用场发射扫描电子显微镜(FE-SEM),透射电子显微镜(TEM),X射线衍射(XRD)等手段对样品进行了表征.结果表明:未经过热处理的TiO2薄膜的晶体结构是非晶态的;在400℃的空气中焙烧2h,薄膜出现锐钛矿相;650℃空气中焙烧2h后,薄膜仍然保持着良好的管状结构.薄膜中Al2O3的存在,抑制了TiO2晶粒的长大,提高了薄膜的热稳定性.关键词:二氧化钛;纳米管阵列薄膜;热稳定性;液相沉积;......
高塑高强纳米Al2O3-Cu复合材料李美霞,罗骥,郭志猛,方哲成,姜冰北京科技大学材料科学与工程学院摘 要:以Cu-Al水雾化合金粉末为原料,通过内氧化方法制备了Al2O3弥散强化铜复合材料,使用场发射扫描电子显微镜(FE-SEM)结合X射线衍射等手段,对复合材料进行了综合研究.结果表明:γ-Al2O3弥散相粒子在基体内均匀分布,尺寸约6nm,间距30~50nm.挤压态棒材的相对导电率为87%IACS,软化温度达850℃.挤压态的25mm弥散强化铜棒材不经过任何中间热处理,直接冷拉拔得到1mm的铜丝,其抗拉强度高达680MPa.关键词:弥散强化铜;内氧化;塑性变形;抗拉强度;......