目的选取Al-18Si-5Ti合金为研究对象,研究Ti Al Si金属间化合物成分、结构和形貌的形成规律。方法通过调整制备工艺(如熔体反应法、液固反应法),改变制备温度和原料(Ti源),可得到板片状或块状的Ti_7Al_5Si_(12)或Ti(Al_(1–x),Si_x)_3...目的选取Al-18Si-5Ti合金为研究对象,研究Ti Al Si金属间化合物成分、结构和形貌的形成规律。方法通过调整制备工艺(如熔体反应法、液固反应法),改变制备温度和原料(Ti源),可得到板片状或块状的Ti_7Al_5Si_(12)或Ti(Al_(1–x),Si_x)_3相。结果使用海绵Ti为原料时,高的熔炼温度倾向于合成板片状Ti_7Al_5Si_(12),而低温则易于形成块状Ti_7Al_5Si_(12);当使用K_2TiF_6、Al-10Ti中间合金或以Al粉、Si粉及Ti粉为原料时,可通过熔体反应或液固扩散反应合成块状的Ti_7Al_5Si_(12)或Ti(Al_(1–x),Si_x)_3相。结论通过对熔体参数调整,可实现Al-Si系合金中TiAlSi相的设计。展开更多
The promoter region of cauliflower mosaic virus (CaMV) 35s RNA was employed to construct an intermediate expression vector which can be used in Ti plasmid system of Agro-bacterium tumefaciens. The original plasmid, wh...The promoter region of cauliflower mosaic virus (CaMV) 35s RNA was employed to construct an intermediate expression vector which can be used in Ti plasmid system of Agro-bacterium tumefaciens. The original plasmid, which contains a polylinker between CaMV 35s RNA and its 3' termination signal in pUC18 was modified to have another antibiotic resistance marker (kanamycin resistance gene Kmr) to facilitate the selection of recombinant with Ti plasmid. Octopine synthase (ocs) structural gene was inserted into this vector downstream of CaMV 35s RNA promoter. This chimaeric gene was introduced into integrative Ti plasmid vector pGV3850, and then transformed into Nicotiana tobaccum cells. A binary plasmid vector was also used to introduce the chimaeric gene into tobacco cells. In both cases, the expression of ocs gene was demonstrated. The amount of oc-topine was much more than the nopaline synthesized by no-paline synthase (nos) gene transferred at the same time with Ti plasmid vector. This demonstrated that CaMV 35s RNA promoter is stronger in transcriptional function than the promoter of nos in tobacco cells.展开更多
文摘目的选取Al-18Si-5Ti合金为研究对象,研究Ti Al Si金属间化合物成分、结构和形貌的形成规律。方法通过调整制备工艺(如熔体反应法、液固反应法),改变制备温度和原料(Ti源),可得到板片状或块状的Ti_7Al_5Si_(12)或Ti(Al_(1–x),Si_x)_3相。结果使用海绵Ti为原料时,高的熔炼温度倾向于合成板片状Ti_7Al_5Si_(12),而低温则易于形成块状Ti_7Al_5Si_(12);当使用K_2TiF_6、Al-10Ti中间合金或以Al粉、Si粉及Ti粉为原料时,可通过熔体反应或液固扩散反应合成块状的Ti_7Al_5Si_(12)或Ti(Al_(1–x),Si_x)_3相。结论通过对熔体参数调整,可实现Al-Si系合金中TiAlSi相的设计。
文摘The promoter region of cauliflower mosaic virus (CaMV) 35s RNA was employed to construct an intermediate expression vector which can be used in Ti plasmid system of Agro-bacterium tumefaciens. The original plasmid, which contains a polylinker between CaMV 35s RNA and its 3' termination signal in pUC18 was modified to have another antibiotic resistance marker (kanamycin resistance gene Kmr) to facilitate the selection of recombinant with Ti plasmid. Octopine synthase (ocs) structural gene was inserted into this vector downstream of CaMV 35s RNA promoter. This chimaeric gene was introduced into integrative Ti plasmid vector pGV3850, and then transformed into Nicotiana tobaccum cells. A binary plasmid vector was also used to introduce the chimaeric gene into tobacco cells. In both cases, the expression of ocs gene was demonstrated. The amount of oc-topine was much more than the nopaline synthesized by no-paline synthase (nos) gene transferred at the same time with Ti plasmid vector. This demonstrated that CaMV 35s RNA promoter is stronger in transcriptional function than the promoter of nos in tobacco cells.
