Ting XIE
,
Min YE
,
Xiaosheng FANG
,
Zhi JIANG
,
Li CHEN
,
Mingguang KONG
,
Yucheng WU
,
Lide ZHANG
材料科学技术（英）
Aluminum nitride (AlN) nanowires, serrated nanoribbons, and nanoribbons were selectively obtained through a simple chloride assisted chemical vapor deposition process. The morphologies of the products could be controlled by adjusting the deposition position and the flux of the reactant gas. The morphologies and structures of the AlN products were investigated in detail. The formation mechanism of the as-prepared different morphologies of AlN one-dimensional (1D) nanostructures was discussed on the basis of the experimental results.
关键词:
Aluminum nitride
,
nitride
,
Morphology-controlled
,
g
Xianting SUN
,
Lianzeng YAO
,
Chimei MO
,
Gang SHI
,
Weili CAI
,
Yimin ZHANG
,
Lide ZHANG
材料科学技术（英）
Alumina aerogels with high porosity of nanometer size were prepared from Al, n-butanol and ethyl acetoacetate by the sol-gel route and the Na supercritical extraction drying technique. Optical experiment results showed that for alumina aerogels after annealing at 500 degrees C for 4 h one intense blue emission band appeared in the wavelength range of 400 to 800 nm, and the optical absorption edge moved from 8.0 eV of coarse grain Al2O3 to 3 similar to 5 eV and with increasing the annealing temperature, this luminescence band presented blue shifts. The reasons of these new optical properties are discussed in detail.
关键词:
Ye ZHANG
,
Lide ZHANG
,
Chimei MO
,
Yuanhong LI
,
Lianzeng YAO
,
Weili CAI
材料科学技术（英）
The synthesis of dispersions of MMA (methylmethacrylate) with different concentrations of oleic acid coated nano-TiO2 particles was performed by hydrolysis of TiCl4 in the mixture solutions of MMA, oleic acid and H2O with various concentrations. When MMA :oleic acid : H2O : TiCl4 1.00 : 0.064 : 0.01 : 0.032 (by mol fraction), the dispersion of MMA with oleic acid coated nano-TiO2 particles was very stable. Optical absorption result showed that the absorption band was located in the ultraviolet range from 200 to 400 nm. This dispersion was added to a kind of automobile surface lustering agent (type II), and then this lustering agent with nano-TiO2 was coated on the surface of automobile surface paint. When the doping amount of the dispersion in the lustering agent=10 vol. pet, the state of paint (color and glossiness) did not present any change after irradiation of an ultraviolet lamp with the power of 1000 watt for two days. The sample with surface paint and lustering agent doped by 10 percent dispersion after suffering from irradiation of the sunlight for half a year (from May to November) kept the original state. However, for the samples with automobile paint and lustering agent without doping of nano-TiO2, the color and glossiness lost easily after irradiation of an ultraviolet lamp. These results prove that nano-TiO2 is a kind of high-efficient additive of paint for protection against ultraviolet irradiation.
关键词:
Xiaosheng FANG
,
Lide ZHANG
,
null
材料科学技术（英）
This article reviews the recent developments in the controlled growth of one-dimensional (1D) oxide nanomaterials, including ZnO, SnO2, In2O3, Ga2O3, SiOx, MgO, and Al2O3. The growth of 1D oxide nanomaterials was carried out in a simple chemical vapor transport and condensation system. This article will begin with a survey of nanotechnology and 1D nanomaterials achieved by many researchers, and then mainly discuss on the controlled growth of 1D oxide nanomaterials with their morphologies, sizes, compositions, and microstructures controlled by altering experimental parameters, such as the temperature at the source material and the substrate, temperature gradient in the tube furnace, the total reaction time, the heating rate of the furnace, the gas flow rate, and the starting material. Their roles in the formation of various morphologies are analyzed and discussed. Finally, this review will be concluded with personal perspectives on the future research directions of this area.
关键词:
Controlled growth
,
null
,
null
,
null
Zhaoyang ZENG
,
Lide ZHANG
,
Xiaohong YAN
材料科学技术（英）
Ballistic transport of Q1D electrons through multiple magnetic barriers is investigated. It is shown that ballistic conductance peaks disappear progressively with the increase of the oscillation frequency of the confining parabolic potential.
关键词:
