Showing papers by "Xiang Zhang published in 1995"

Thermal conductivity and diffusivity of free‐standing silicon nitride thin films

Abstract: The thermal conductivity and diffusivity of free‐standing silicon nitride (Si‐N) films of 0.6 and 1.4 μm in thickness are measured. A new experimental technique, the amplitude method, is proposed and applied to measurement of the thin‐film thermal diffusivity. The thermal diffusivity is determined by three independent experimental approaches: the phase‐shift method, the amplitude method, and the heat‐pulse method. Good agreement among the measured thermal diffusivities obtained by the three methods indicates the validity of the amplitude method. High‐resolution electron microscopy studies show a large quantity of voids in the 1.4 μm Si‐N films. In contrast, very few voids are found in the 0.6 μm films. This difference may be responsible for the measured lower conductivity of the 1.4 μm Si‐N films as compared to the 0.6 μm thin films.

The strain relaxation of In0.1Ga0.9As on GaAs (110) grown by molecular beam epitaxy

Abstract: The strain relaxation of In0.1Ga0.9As layers on GaAs (110) was studied by transmission electron microscopy (TEM) and x‐ray diffraction. TEM observation showed that strain relief in the (110) interface is initially dominated in the [001] direction by the formation of 60° type dislocations and stacking faults via {111}〈011〉 slip systems for layer thicknesses up to approximately 200 nm. As the layer thickness increases, {113}〈011〉 slip systems became active and the resultant misfit dislocations contribute strain relief in both [001] and [110] directions. The efficiency of strain relief by the different misfit dislocations is discussed.

cDNA clones of differential expression between human normal liver tissue and hepatocarcinoma

Abstract: Using mRNA differential display technique, we studied the interesting cDNA clones of differential expression between human normal liver and hepatocarcinoma. mRNA extracted from normal liver tissue and hepatocarcinoma cell line Hep3B were subjected to RT-PCR reaction with ten combinations of two 3' primers and five 5' primers. After subjecting these PCR products to labelling with 35S(a)-dATP, PAGE and autoradiography, we obtained a lot of cDNA clones of differential expression. Thirty-one of these clones were partially sequenced. It was shown that 30 clones had no sequences matched with GenBank except one. Dot hybridization showed that 2 cDNA clones were overexpressed in liver cancer tissue and 1 cDNA clone was overexpressed in normal liver tissue. The further characterization of these cDNA clones is in progress.