In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain size.Effect of pre-strain and grain size on me-chanical property ...In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain size.Effect of pre-strain and grain size on me-chanical property was investigated through tensile tests.Microstructures of the pre-strained and tensile tested samples were analyzed,respectively.The 30.8°v-bending and following flattening,as well as Erichson cupping tests,were performed on the pre-strained samples.Results show the elongation ratio of grain and dislocation density increases with pre-strain.Yielding platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning effect.The 30.8°v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain size.Decrease in grain size,along with increase in pre-strain,causes increase in strength and decrease in elongation rate as well as cupping value.Pre-strain causes very slight effect on bending ability,much less than that on mechanical property and cupping test value.Reciprocal impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.展开更多
以暴露于β-萘黄酮(beta-Naphthoflavone,β-NF)中的剑尾鱼(Xiphophorus helleri)为研究对象,采用SMARTTM(Switching Mechanism At 5' end of RNA Transcript)技术,成功构建了剑尾鱼肝脏cDNA文库。该文库约含有4.2×107个重组子...以暴露于β-萘黄酮(beta-Naphthoflavone,β-NF)中的剑尾鱼(Xiphophorus helleri)为研究对象,采用SMARTTM(Switching Mechanism At 5' end of RNA Transcript)技术,成功构建了剑尾鱼肝脏cDNA文库。该文库约含有4.2×107个重组子,重组效率达l00%,插入片段多在0.6～2.5kb之间,平均插入片段长度约1.3kb,扩增后文库滴度为7.0×109CFU/mL。随机挑取200个重组子进行测序检验,共得到长度大于500bp的Expression sequence tag(EST)序列187个,对所测EST序列进行拼接,得到16个重叠群(Contigs),81个单拷贝EST,总计单基因簇97个。结果表明,剑尾鱼肝脏的全长cDNA文库已构建成功,且质量较高,从而为筛选剑尾鱼肝脏的功能基因全长序列奠定了基础。展开更多
基金Funded by Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2020JJA160034)the Basic Ability Improvement of Middle and Young Teachers in Guangxi Universities Foundation(No.2020KY21018)。
文摘In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain size.Effect of pre-strain and grain size on me-chanical property was investigated through tensile tests.Microstructures of the pre-strained and tensile tested samples were analyzed,respectively.The 30.8°v-bending and following flattening,as well as Erichson cupping tests,were performed on the pre-strained samples.Results show the elongation ratio of grain and dislocation density increases with pre-strain.Yielding platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning effect.The 30.8°v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain size.Decrease in grain size,along with increase in pre-strain,causes increase in strength and decrease in elongation rate as well as cupping value.Pre-strain causes very slight effect on bending ability,much less than that on mechanical property and cupping test value.Reciprocal impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.
文摘以暴露于β-萘黄酮(beta-Naphthoflavone,β-NF)中的剑尾鱼(Xiphophorus helleri)为研究对象,采用SMARTTM(Switching Mechanism At 5' end of RNA Transcript)技术,成功构建了剑尾鱼肝脏cDNA文库。该文库约含有4.2×107个重组子,重组效率达l00%,插入片段多在0.6～2.5kb之间,平均插入片段长度约1.3kb,扩增后文库滴度为7.0×109CFU/mL。随机挑取200个重组子进行测序检验,共得到长度大于500bp的Expression sequence tag(EST)序列187个,对所测EST序列进行拼接,得到16个重叠群(Contigs),81个单拷贝EST,总计单基因簇97个。结果表明,剑尾鱼肝脏的全长cDNA文库已构建成功,且质量较高,从而为筛选剑尾鱼肝脏的功能基因全长序列奠定了基础。
