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991.
Lihui SunHongwei Qin Feng GaoEnsi Cao Kai FanJifan Hu 《Applied Surface Science》2011,257(7):2633-2636
The adsorption of CO, NH3 and O2 gas molecules on Fe site of La0.875Sr0.125FeO3 (0 1 0) surface has been investigated based on the density functional theory (DFT) with the spin polarized generalized gradient approximation (GGA). The optimal adsorption orientations as well as the adsorption energies for these molecules adsorption on Fe site of La0.875Sr0.125FeO3 (0 1 0) surface are derived. Results show that adsorption configurations with C-down for CO, N-down for NH3 are stable. For the O2 molecule adsorption, the mode with an angle about 120° between the oxygen molecule and La0.875Sr0.125FeO3 (0 1 0) surface is stable. 相似文献
992.
In this paper, porous WO3 films were prepared by anodic oxidation of metallic tungsten (W) films deposited on alumina substrates. The structural and morphological properties of the porous WO3 films were investigated using field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD). A large number of cracks appeared on the surface of films after anodization, which makes the films porous. The porous WO3 sensors achieved their maximum response values to NO2 at a low operating temperature of 150 °C. The porous WO3 sensors showed high response values, great stability and fast response-recovery characteristics to different concentration of NO2 gas due to the high specific surface area and special structural and morphological properties. 相似文献
993.
Yan-Huai Ding Ping ZhangHu-Ming Ren Qin ZhuoZhong-Mei Yang Xu JiangYong Jiang 《Applied Surface Science》2011,258(3):1077-1081
Surface adhesion properties are important to various applications of graphene-based materials. Atomic force microscopy is powerful to study the adhesion properties of samples by measuring the forces on the colloidal sphere tip as it approaches and retracts from the surface. In this paper we have measured the adhesion force between the colloid probe and the surface of graphene (graphene oxide) nanosheet. The results revealed that the adhesion force on graphene and graphene oxide surface were 66.3 and 170.6 nN, respectively. It was found the adhesion force was mainly determined by the water meniscus, which was related to the surface contact angle of samples. 相似文献
994.
R. Qin D.Y. Ding C.Q. NingH.G. Liu B.S. ZhuM. Li D.L. Mao 《Applied Surface Science》2011,257(14):6308-6313
Self-organized Ni-Ti-O nanotube arrays were fabricated through a direct anodization of NiTi shape memory alloy in glycerol-based electrolyte. The growth of Ni-doped TiO2 nanotube arrays was mainly affected by anodization voltage and temperature. Higher anodization voltage facilitated the growth of uniform nanotube arrays. Large-area open-ended Ni-Ti-O nanotube arrays could form on the surface of the shape memory alloy under a higher anodization temperature. The oxide nanotubes had a gradually changed composition along the growth direction of the nanotube and presented a thermal stability up to 400 °C. The nanotubular oxide demonstrated a much better hydrophilic behavior than that of the traditional oxide layer grown on NiTi substrate through air oxidization. The successful fabrication of Ni-doped TiO2 nanotube arrays here makes it feasible to further explore excellent physical and chemical as well as biomedical properties of the nanotube-modified surfaces of the NiTi shape memory alloy. 相似文献
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The endcap of time-of-flight (ETOF) detector in BES (Beijing Spectrometer) III is planned to be upgraded by using multi-gap resistive plate chambers (MRPCs) and the designed time resolution of the MRPCs is around 50 ps. Thus a time-zero (T0) detector needs to be built to offer a high quality reference time for the MRPCs beam test. So a T0 detector is built using plastic scintillator tiles (BC420) to couple with four fast phototubes (PMTs, Hamamatsu H6533). The timing properties of the detector is studied by using a cosmic ray test and factors related to the time resolution, such as plastic scintillator size, readout mode and angle effects, are discussed. T0 detector timing resolutions of ~41-62 ps are achieved, which means that the T0 detector can be used in the MRPC beam test. 相似文献
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高光谱技术分析茶树叶片中叶绿素含量及分布 总被引:4,自引:0,他引:4
植物叶片叶绿素含量及分布是植物营养信息表达的一个重要指标.以茶树为研究对象,利用高光谱技术分析茶树叶片中叶绿素含量及其分布.通过采集茶树鲜叶的高光谱图像,利用7种不同的算法从高光谱数据中提取相应的特征参数,并根据特征参数和叶绿素含量的参考测量值分别拟合出相应的预测模型.结果显示,二次土壤调节植被指数算法提取的特征参数最... 相似文献
1000.