Synthetic silicides with good properties were prepared,as Y ions were implanted into silicon using metal vapor vacuum arc (MEVVA) ion implantor and annealed by Rapid Thermal Annealing (RTA).The structure of synthetic ...Synthetic silicides with good properties were prepared,as Y ions were implanted into silicon using metal vapor vacuum arc (MEVVA) ion implantor and annealed by Rapid Thermal Annealing (RTA).The structure of synthetic silicides has been investigated with the analysis of channeled low angle emergence and TEM.Three layers could be observed in the implanted region as the implanting ion flux is selected as 25μA/cm\+2.The thickness of the silicide layer is about 60—80nm.The defect density N \-d and sheet resistance R \-s decrease with the increase of the ion flux.After RTA annealing of the implanted sample,the N\-d and R\-s decreased obviously.R\-s decreased from 54Ω/□ to 14Ω/□.The minimum of resistivity is 84μΩ·cm.It is evident that electrical properties of the Y silicides can be improved by RTA.The formation of the silicides with YSi and YSi\-2 are confirmed by X\|ray diffraction (XRD) analysis.With the analysis of low angle emergence,important information exposed from the depth profiles of atoms and lattice distortion in an implanted region would be used to study the synthesis of silicides.展开更多
In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from ...In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from Jinhong Chemical Plant at Weihai city, by the methods of quick isolation and screening of halophilie bacteria. Systematic studies on it were carried out. Results show that the strain JSA1 is bacillus. The temperature range most suitable for its growth is 29 - 35 ℃ and the most suitable pH is 6. 5 - 9. 0. It can grow well at the salt mass concentration of 30 - 150 g/L. The C ＋ G mole fraction of its DNA is 37.5%. The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophilus （DQ359731） of Alkalibacillts. Their similarities are as high as 99%. However, they have obvious differences in aspects of whole-cell main fatty acid components, cell size, cell morphology, motility, oxidase, gelatine liquefication, NaCl tolerance range, pH tolerance range, G ＋ C mole fraction, sole carbon source, sole nitrogen source, antibiotic sensitivity and strain source. Comparing with other species of the same genus, differences of this strain are even more obvious. In view of muhiple identification results, we believe this strain is a new subspecies ofAlkalibacillus halophilus and name it Alkalibacillus halophilus subsp, hitensis subsp, nov.展开更多
The thermal stability of five commercial ion-exchange resin catalysts was studied by means of thermal gravimetric analysis （TGA） at elevated temperatures of up to 600℃ and isothermal temperatures in the range of 15...The thermal stability of five commercial ion-exchange resin catalysts was studied by means of thermal gravimetric analysis （TGA） at elevated temperatures of up to 600℃ and isothermal temperatures in the range of 150℃ and 200 ℃. Resin samples with different initial water contents were also investigated. The study indicated that TGA, as a complementary evaluating method for the plug flow reactor system approach, could be used as a fast analyzing means for study on the thermal stability of ion-exchange resin catalysts. The stoichiometric calculation of the isothermally treated resin catalysts based on the FTIR analysis and acid capacity confirmed that the weight loss of the resins at 150℃ and 200℃ was caused by the desulfonation process and that desulfonation occurred mainly at the para-position of the benzene ring in the resins. H＋ ions and moisture played an important role in the desulfonation process.展开更多
基金Project Supported by National Natural Science Foundation of China ( Grant No.59671 0 51 ) and by National HighTechnology Resea
文摘Synthetic silicides with good properties were prepared,as Y ions were implanted into silicon using metal vapor vacuum arc (MEVVA) ion implantor and annealed by Rapid Thermal Annealing (RTA).The structure of synthetic silicides has been investigated with the analysis of channeled low angle emergence and TEM.Three layers could be observed in the implanted region as the implanting ion flux is selected as 25μA/cm\+2.The thickness of the silicide layer is about 60—80nm.The defect density N \-d and sheet resistance R \-s decrease with the increase of the ion flux.After RTA annealing of the implanted sample,the N\-d and R\-s decreased obviously.R\-s decreased from 54Ω/□ to 14Ω/□.The minimum of resistivity is 84μΩ·cm.It is evident that electrical properties of the Y silicides can be improved by RTA.The formation of the silicides with YSi and YSi\-2 are confirmed by X\|ray diffraction (XRD) analysis.With the analysis of low angle emergence,important information exposed from the depth profiles of atoms and lattice distortion in an implanted region would be used to study the synthesis of silicides.
基金Sponsored by the Science Foundation of Harbin Institute of Technology(Grant No. HIT(WH)XB200804)the National Basic Research Program of China(973 Program)(Grant No. 2004CB185050)
文摘In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from Jinhong Chemical Plant at Weihai city, by the methods of quick isolation and screening of halophilie bacteria. Systematic studies on it were carried out. Results show that the strain JSA1 is bacillus. The temperature range most suitable for its growth is 29 - 35 ℃ and the most suitable pH is 6. 5 - 9. 0. It can grow well at the salt mass concentration of 30 - 150 g/L. The C ＋ G mole fraction of its DNA is 37.5%. The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophilus （DQ359731） of Alkalibacillts. Their similarities are as high as 99%. However, they have obvious differences in aspects of whole-cell main fatty acid components, cell size, cell morphology, motility, oxidase, gelatine liquefication, NaCl tolerance range, pH tolerance range, G ＋ C mole fraction, sole carbon source, sole nitrogen source, antibiotic sensitivity and strain source. Comparing with other species of the same genus, differences of this strain are even more obvious. In view of muhiple identification results, we believe this strain is a new subspecies ofAlkalibacillus halophilus and name it Alkalibacillus halophilus subsp, hitensis subsp, nov.
基金supported financially by the Purolite Company and Chinese National Natural Science Foundation(20674069)
文摘The thermal stability of five commercial ion-exchange resin catalysts was studied by means of thermal gravimetric analysis （TGA） at elevated temperatures of up to 600℃ and isothermal temperatures in the range of 150℃ and 200 ℃. Resin samples with different initial water contents were also investigated. The study indicated that TGA, as a complementary evaluating method for the plug flow reactor system approach, could be used as a fast analyzing means for study on the thermal stability of ion-exchange resin catalysts. The stoichiometric calculation of the isothermally treated resin catalysts based on the FTIR analysis and acid capacity confirmed that the weight loss of the resins at 150℃ and 200℃ was caused by the desulfonation process and that desulfonation occurred mainly at the para-position of the benzene ring in the resins. H＋ ions and moisture played an important role in the desulfonation process.
