Xiaoyi Shen Yuchun Zhai Yang Sun Huimin Gu
材料科学技术（英文）
Monodisperse spherical SiO2 particles were successfully synthesized in 2-propanol-H2O-NH3 system by the microwave hydrothermal method using ammonia as catalyst. To investigate the influences on the size of spherical SiO2 particles, factors such as ammonia concentration, reaction temperature, stirring intensity and reactants mol ratio have been studied. The orthogonal experiments were carried out. The as-prepared SiO2 particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and differential thermal analysis (DTA). The results indicated that the size of SiO2 particles increased greatly with the increase in ammonia concentration, temperature and reactants mol ratio, but increased slightly with the increase in stirring intensity. Monodisperse spherical SiO2 particles were amorphous with perfect sphere and uniform size. Hydroxyl was detected in SiO2. Kinetic parameters were calculated, and finally the reaction rate equation of dehydrated hydroxyl was obtained.
关键词:
Monodisperse spherical SiO2 particle
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Microwave hydrothermal method
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Amorphous
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Reaction rate equation
Canying CAI
,
Qibin YANG
,
Hongrong LIU
材料科学技术（英文）
Assuming that the wave function , the Schrodinger equation can be written as . Neglecting the last two terms, an analytical expression of electron dynamical diffraction was derived by Qibin YANG et al. In this paper, the analytical expression is modified by further considering the second-order differential term . When the accelerating voltage is not very high, or the sample is not very thin, the reciprocal vector ɡ is large, the modification of the second-order differential is necessary; otherwise it can be neglected.
关键词:
Electron dynamical diffraction
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null
陈志钢
,
唐一文
,
张丽莎
,
张新
,
贾志勇
,
余颖
材料科学与工程学报
doi:10.3969/j.issn.1673-2812.2005.04.025
以透明导电玻璃(TCO)、纳米TiO2/TCO、CNTs/TCO、铜片分别为工作电极,用简单铜盐通过阴极还原制备了Gu2O薄膜,并研究了溶液温度和衬底对电化学沉积Gu2O薄膜形貌的影响.结果表明:以TCO和铜片为衬底时,由于表面微粒为微米级,不管溶液温度高低,只能得到微米级的Cu2O薄膜;以纳米TiO2/TCO和CNTs/TCO为衬底,池温高于30℃只能得到微米级的Cu2O薄膜,而池温降到0℃时,都可得到纳米Cu2O.
关键词:
氧化亚铜
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电沉积
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溶液温度
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衬底
李强
,
宣益民
工程热物理学报
建立了测量小通道扁管内纳米流体流动与对流换热性能的实验系统,测量了不同粒子体积份额的水-Gu纳米流体的管内对流换热系数和摩擦阻力系数,实验结果表明,在相同雷诺教条件下,小通道扁管内纳米流体的对流换热系数大于纯液体,且随粒子的体积份额的增加而增大,而纳米流体的阻力系教并未明显增大.
关键词:
纳米流体
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强化传热
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小通道扁管
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
颜慧成
,
郭征
,
张孟亭
,
张洪平
钢铁研究学报
引入变量m(冲量密度)和Yang-Mills型规范变换m=u+gradφ,将原始变量的N-S方程转化为规范-不变量形式,用自由质点法处理Voronoi元,对连铸结晶器弯月面处保护渣流动行为进行数学模拟.输出振动周期内的动态流场,然后结合一组试验数据进行计算,计算结果与实际情况相吻合,进而讨论了渣圈对液渣流动行为的影响,为研究结晶器弯月面处保护渣的行为和铸坯振痕的形成提供了一定的依据.
关键词:
连续铸钢
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保护渣
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流动行为
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数学模拟
董企铭
,
苏娟华
,
刘平
,
李贺军
,
康布熙
材料热处理学报
doi:10.3969/j.issn.1009-6264.2004.03.010
通过能谱和透射电镜分析研究了Gu-0.3Cr-0.15Zr-0.05Mg合金的时效析出,在4790℃时效4h形成了有序的原子排列,其化合物类型为CrCu2(ZrMg);同时存在体心的Cr相和面心的Cu4Zr相,在晶界上有少量未溶的Cr粒子.细小弥散的析出相使合金的性能得以提高,470℃时效4h～6h,硬度和导电率分别达109～108HV,79%IACS～80%IACS.
关键词:
Cu-Cr-Zr-Mg合金
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微观组织
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析出
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时效性能
周镇
,
艾育华
,
孔文俊
工程热物理学报
本文利用双腔泄压式定压燃烧弹,研究了高压下典型IGCC合成气的层流火焰传播特性,得到了不同压力(0.1～1 MPa)和不同当量比下(0.6～3.0)合成气的层流火焰传播速度和Markstein长度.实验结果表明,层流火焰传播速度随当量比先增加后减少,随压力的增加而减小.Davis和Sun机理能较好地预测高压下合成气层流火焰的传播速度.Markstein长度随当量比的增加而增加,随压力的增加而减小.
关键词:
合成气
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球形火焰
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层流火焰传播速度
,
Markstein长度
