A Li-B alloy has been prepared using a pretreated amorphous B powder and pure Li ingot as starting materials by continually slow addition of B powder and intensified stirring in the process of melting. The microstruct...A Li-B alloy has been prepared using a pretreated amorphous B powder and pure Li ingot as starting materials by continually slow addition of B powder and intensified stirring in the process of melting. The microstructure and the discharge characteristic of the materials have been investigated- Results show that the problem of temperature control in synthesis would be modified by means of continual addition of B powder, the Li7B6 would be more finely distributed in the metal Li by means of intensified stirring. The discharge characteristic of the Li-B alloy using amorphous B as starting materials is almost the same with that of using crystalline B.展开更多
The key intermediate 5 for synthesis of the contragestationally active diterpenoid grandiflorenic acid(1)and its analogues 2 and 3 was prepared and an acetyl transposition reaction occurred in the SeO_2 oxida- tion of 8.
FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their stru...FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.展开更多
Microwave electron cyclotron resonance plasma enhanced chemical vapor depositionwas used to grow silicon dioxide films on crystalline silicon substrate for planar optical waveguides.The relationship between plasma par...Microwave electron cyclotron resonance plasma enhanced chemical vapor depositionwas used to grow silicon dioxide films on crystalline silicon substrate for planar optical waveguides.The relationship between plasma parameters and deposition rates was investigated, and the influ-ence of radio frequency substrate bias on properties of SiO2 films was also preliminarily studied.X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron mi-croscopy, atomic force microscopy and elllipsometry were used to characterize the deposited films,showing that SiO2 films with good structural and optical properties prepared at low temperaturehave been achieved. They can basically meet the requirements of integrated optical waveguides.展开更多
A softening zone with recrystallized grain around the prepared crack tip in the shock waves treated C-Mn steel weld metal was observed. It is suggested that a dynamic recovery occurred around the prepared crack tip ev...A softening zone with recrystallized grain around the prepared crack tip in the shock waves treated C-Mn steel weld metal was observed. It is suggested that a dynamic recovery occurred around the prepared crack tip even at a low explosion pressure (5 GPa) because of the stress and strain concentration at the crack tip when shock waves pass through. This result supports the previous work on the improved mechanical properties of a shock treated welded joint with residual crack from the viewpoint of microstructure.展开更多
Monodispersed potymeric microparticles were prepared by seed-poly- merization.High performance packings were obtained for anion chromatography by coating the surface-sutfonated partictes with quarternized latexes.
Foreign investors wishing to establish a joint venture with a Chinese partner in China are requested to submit a feasibility study report to the department in charge as done abroad. The article given below describes h...Foreign investors wishing to establish a joint venture with a Chinese partner in China are requested to submit a feasibility study report to the department in charge as done abroad. The article given below describes how to write a feasibility study report according to the Chinese practical situation.展开更多
基金State Ministry of Education Under contract No. 96053311.
文摘A Li-B alloy has been prepared using a pretreated amorphous B powder and pure Li ingot as starting materials by continually slow addition of B powder and intensified stirring in the process of melting. The microstructure and the discharge characteristic of the materials have been investigated- Results show that the problem of temperature control in synthesis would be modified by means of continual addition of B powder, the Li7B6 would be more finely distributed in the metal Li by means of intensified stirring. The discharge characteristic of the Li-B alloy using amorphous B as starting materials is almost the same with that of using crystalline B.
文摘The key intermediate 5 for synthesis of the contragestationally active diterpenoid grandiflorenic acid(1)and its analogues 2 and 3 was prepared and an acetyl transposition reaction occurred in the SeO_2 oxida- tion of 8.
文摘FeTi_1-O_2（= 0.00,0.05,0.10） nanocomposites are synthesized using a sol-gel method involving an ethanol solvent in the presence of ethylene glycol as the stabilizer,and acetic acid as the chemical reagent.Their structural and optical analyses are studied to reveal their physicochemical properties.Using the x-ray diffractometer（XRD）analysis,the size of the nanoparticles（NPs） is found to be 18-32 nm,where the size of the NPs decreases down to 18 nm when Fe impurity of up to 10% is added,whereas their structure remains unchanged.The results also indicate that the structure of the NPs is tetragonal in the anatase phase.The Fourier transform infrared spectroscopy analysis suggests the presence of a vibration bond（Ti-O） in the sample.The photoluminescence analysis indicates that the diffusion of Fe^（3＋） ions into the TiO_2 matrix results in a decreasing electron-hole recombination,and increases the photocatalytic properties,where the best efficiency appears at an impurity of10%.The UV-diffuse reflection spectroscopy analysis indicates that with the elevation of iron impurity,the band gap value decreases from 3.47 eV for the pure sample to 2.95 eV for the 10 mol% Fe-doped TiO_2 NPs.
文摘Microwave electron cyclotron resonance plasma enhanced chemical vapor depositionwas used to grow silicon dioxide films on crystalline silicon substrate for planar optical waveguides.The relationship between plasma parameters and deposition rates was investigated, and the influ-ence of radio frequency substrate bias on properties of SiO2 films was also preliminarily studied.X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron mi-croscopy, atomic force microscopy and elllipsometry were used to characterize the deposited films,showing that SiO2 films with good structural and optical properties prepared at low temperaturehave been achieved. They can basically meet the requirements of integrated optical waveguides.
基金The investigation is supported by the WeIding Labc--ratory, Institute of Metal Research of Chinese Atedemy Qf SciEllcGs.
文摘A softening zone with recrystallized grain around the prepared crack tip in the shock waves treated C-Mn steel weld metal was observed. It is suggested that a dynamic recovery occurred around the prepared crack tip even at a low explosion pressure (5 GPa) because of the stress and strain concentration at the crack tip when shock waves pass through. This result supports the previous work on the improved mechanical properties of a shock treated welded joint with residual crack from the viewpoint of microstructure.
文摘Monodispersed potymeric microparticles were prepared by seed-poly- merization.High performance packings were obtained for anion chromatography by coating the surface-sutfonated partictes with quarternized latexes.
文摘Foreign investors wishing to establish a joint venture with a Chinese partner in China are requested to submit a feasibility study report to the department in charge as done abroad. The article given below describes how to write a feasibility study report according to the Chinese practical situation.
