To obtain pure DNA directly from some complex forest soils are still very difficulty at present,though many methods even commercial kits have been attempted.This paper reports an economic and efficient method for furt...To obtain pure DNA directly from some complex forest soils are still very difficulty at present,though many methods even commercial kits have been attempted.This paper reports an economic and efficient method for further purifying crude DNA extracted from forest soils with two steps.First,the crude DNA was dissolved using the extraction buffer,which removed the debris by chloroform-isoamyl alcohol,and then reprecipitated the DNA by isopropanol;second,the recovered DNA was further purified with silica spin column.Results show that 82-91% of the humic acids was removed by step one.The remaining humic acids could be completely effaced through the second step.The recovered DNA following this protocol was quite pure and ready for sensitive conventional PCR reactions.This is an economic,efficient,and timesaving method.Moreover,crude DNA extracted by other methods can be also further purified with this new way.展开更多
Microstructural stability of IN939 superalloy with two different manufacturing routes was investigated during long-term aging at elevated temperatures by light optical microscope(OM) and scanning electron microscope...Microstructural stability of IN939 superalloy with two different manufacturing routes was investigated during long-term aging at elevated temperatures by light optical microscope(OM) and scanning electron microscope(SEM) equipped with an EDS system.The results show mat the coarsening behavior of γ' particles is primarily impacted by the initial heat treatment conditions,and the effect of the prior manufacturing route(casting or hot forming) is found to be insignificant,if any,on the γ' particles coarsening kinetics.In the temperature range of 790-827 ℃,IN939 cast/wrought-HT2 alloys have more microstructural stability,while in the temperature range of 827-910 ℃,the initial heat treatment marked as HT1 provides more stable microstructure for the cast or wrought IN939 superalloy.展开更多
基金supported by Project of National Science Foundation of China (30870419, 40971151)the National Basic Research Program of China (2008CB418004)the Open Research Foundation of Key Laboratory for Modern Sylvicultural Technology of Zhejiang Province (200605), Zhejiang Forestry College,China
文摘To obtain pure DNA directly from some complex forest soils are still very difficulty at present,though many methods even commercial kits have been attempted.This paper reports an economic and efficient method for further purifying crude DNA extracted from forest soils with two steps.First,the crude DNA was dissolved using the extraction buffer,which removed the debris by chloroform-isoamyl alcohol,and then reprecipitated the DNA by isopropanol;second,the recovered DNA was further purified with silica spin column.Results show that 82-91% of the humic acids was removed by step one.The remaining humic acids could be completely effaced through the second step.The recovered DNA following this protocol was quite pure and ready for sensitive conventional PCR reactions.This is an economic,efficient,and timesaving method.Moreover,crude DNA extracted by other methods can be also further purified with this new way.
文摘Microstructural stability of IN939 superalloy with two different manufacturing routes was investigated during long-term aging at elevated temperatures by light optical microscope(OM) and scanning electron microscope(SEM) equipped with an EDS system.The results show mat the coarsening behavior of γ' particles is primarily impacted by the initial heat treatment conditions,and the effect of the prior manufacturing route(casting or hot forming) is found to be insignificant,if any,on the γ' particles coarsening kinetics.In the temperature range of 790-827 ℃,IN939 cast/wrought-HT2 alloys have more microstructural stability,while in the temperature range of 827-910 ℃,the initial heat treatment marked as HT1 provides more stable microstructure for the cast or wrought IN939 superalloy.