To study the promoter activities of genes cpcT 2 and cpcS 2,several upstream DNA fragments of these two genes with different lengths were selected.These fragments were fused with promoterless gfp（reporter gene） for ...To study the promoter activities of genes cpcT 2 and cpcS 2,several upstream DNA fragments of these two genes with different lengths were selected.These fragments were fused with promoterless gfp（reporter gene） for constructing five recombinant plasmids.Then,these recombinant plasmids were transferred into Nostoc PCC 7120 by conjugation.The promoter activities of genes cpcT 2 and cpcS 2 were determined by observing the fluorescence of green fluorescent protein（GFP） with a fluorescence microscope.The result showed that the 1 300 bp（-1 300 to 0 bp） and 2 600 bp（-2 600 to 0 bp） upstream fragments of cpcT 2 had strong promoter activity and the promoter activity of the 680 bp（-680 to 0 bp） fragment was weaker than that of two above fragments of cpcT 2.The 2 000 bp（-2 000 to 0 bp） upstream fragment of cpcS 2 revealed weak promoter activity.This showed that a strong promoter of cpcT 2 was located in the upstream fragment between-680 and-1 300 bp.展开更多
Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necess...Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.展开更多
基金Supported by the National Natural Science Foundation of China(30870541, 31070743)China Postdoctoral Science Foundation (20100471191)
文摘To study the promoter activities of genes cpcT 2 and cpcS 2,several upstream DNA fragments of these two genes with different lengths were selected.These fragments were fused with promoterless gfp（reporter gene） for constructing five recombinant plasmids.Then,these recombinant plasmids were transferred into Nostoc PCC 7120 by conjugation.The promoter activities of genes cpcT 2 and cpcS 2 were determined by observing the fluorescence of green fluorescent protein（GFP） with a fluorescence microscope.The result showed that the 1 300 bp（-1 300 to 0 bp） and 2 600 bp（-2 600 to 0 bp） upstream fragments of cpcT 2 had strong promoter activity and the promoter activity of the 680 bp（-680 to 0 bp） fragment was weaker than that of two above fragments of cpcT 2.The 2 000 bp（-2 000 to 0 bp） upstream fragment of cpcS 2 revealed weak promoter activity.This showed that a strong promoter of cpcT 2 was located in the upstream fragment between-680 and-1 300 bp.
文摘Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.
