In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-...In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were produced.Compared to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process cycle.The compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear deformation.From the base material to the rod,the material experienced three stages,i.e.deformation by the tool,upward flow with additional tilt,followed by upward transportation.The microstructural evolution was revealed by“stop-action”technique.The microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.展开更多
This study dealt with the rhythmic Qian 3410 of the intersalt shale series in the Qianjiang Depression,in which the geological condition for oil accumulation in the rhythmic shale was investigated by using the basic d...This study dealt with the rhythmic Qian 3410 of the intersalt shale series in the Qianjiang Depression,in which the geological condition for oil accumulation in the rhythmic shale was investigated by using the basic drilling,core and well logging data,as well as data obtained from the thin section identification,SEM,mercury injection,X-ray diffraction and rock freezing heat analyses.The study result indicated that:1)the intersalt shale series are characterized by TOC in a range of 0.35%-6.38%(averaging 3.19%),Types I and II1 organic matter,and from immature to mature oil,indicative of a potential for generating a great volume of immature oil;2)in the target layer,mineral compositions are complicated,which can divide into argillaceous dolomite facies,argillaceous limestone facies,dolomitic mudstone facies,and calcium-mirabilite-filling dolomitic mudstone facies;and 3)of them,the argillaceous dolomite facies is the most contributory,with reservoir spaces consisting of intergranular pores as dominant,as well as rare dissolution pores and seams.It is characterized by high organic abundance(4.23%-6.38%),high content of brittle mineral(50%-71%),low content of clay mineral(18%-33%),high porosity(10.8%-26.3%)and good oil-bearing properties(S1 distributed in 3.48-5.64 mg/g,and S1/TOC value in a range of 348-564 oil mg/g).Therefore,the argillaceous dolomite facies was considered the key target series to be explored for the intersalt shale oil in the study area in the coming days.展开更多
To date,the genetic transformation system of watermelon has remained inefficient.In this study,the genetic transformation system of watermelon mediated by Agrobacterium tumefaciens was optimized,including different se...To date,the genetic transformation system of watermelon has remained inefficient.In this study,the genetic transformation system of watermelon mediated by Agrobacterium tumefaciens was optimized,including different seedling ages,strains of Agrobacterium tumefaciens,concentrations of acetosyringone infected solution,co-culture time,selection pressure of antibiotics timentin and glufosinate,and concentrations of hormones 6-benzylaminopurine,indoleacetic acid and naphthylacetic acid in the corresponding culture medium.Our results suggested that cotyledons would be used as explants,disinfected with 6%sodium hypochlorite for 12 min,cultured for 3 d,and then infected with Agrobacterium inoculum(Agrobacterium EHA105)containing 200μM acetosyringone and 0.02 of final OD_(600).The explants differentiated into adventitious shoots in the medium with 1.5 mg/L 6-benzylaminopurine and 200μM timentin.Positive adventitious shoots were obtained through further screening by 1.4 mg/L herbicide glufosinate-ammonium,and were induced by 0.1 mg/L naphthalene acetic acid into independent plants.Our system improves the genetic transformation efficiency of watermelon and provides a technical basis for continuous acquisition of watermelon transgenic plants.展开更多
基金the China Scholarship Council for the award of fellowship and funding(No.202006230137)。
文摘In order to obtain Mg alloys with fine microstructures and high mechanical performances,a novel friction-based processing method,name as“constrained friction processing(CFP)”,was investigated.Via CFP,defect-free Mg-Zn-Ca rods with greatly refined grains and high mechanical properties were produced.Compared to the previous as-cast microstructure,the grain size was reduced from more than 1 mm to around 4μm within 3 s by a single process cycle.The compressive yield strength was increased by 350%while the ultimate compressive strength by 53%.According to the established material flow behaviors by“tracer material”,the plastic material was transported by shear deformation.From the base material to the rod,the material experienced three stages,i.e.deformation by the tool,upward flow with additional tilt,followed by upward transportation.The microstructural evolution was revealed by“stop-action”technique.The microstructural development at regions adjacent to the rod is mainly controlled by twinning,dynamic recrystallization(DRX)as well as particle stimulated nucleation,while that within the rod is related to DRX combined with grain growth.
基金funded by the 2018 Undergraduate Training Program for Innovation and Entrepreneurship of Yangtze University,the project number is 2018267.
文摘This study dealt with the rhythmic Qian 3410 of the intersalt shale series in the Qianjiang Depression,in which the geological condition for oil accumulation in the rhythmic shale was investigated by using the basic drilling,core and well logging data,as well as data obtained from the thin section identification,SEM,mercury injection,X-ray diffraction and rock freezing heat analyses.The study result indicated that:1)the intersalt shale series are characterized by TOC in a range of 0.35%-6.38%(averaging 3.19%),Types I and II1 organic matter,and from immature to mature oil,indicative of a potential for generating a great volume of immature oil;2)in the target layer,mineral compositions are complicated,which can divide into argillaceous dolomite facies,argillaceous limestone facies,dolomitic mudstone facies,and calcium-mirabilite-filling dolomitic mudstone facies;and 3)of them,the argillaceous dolomite facies is the most contributory,with reservoir spaces consisting of intergranular pores as dominant,as well as rare dissolution pores and seams.It is characterized by high organic abundance(4.23%-6.38%),high content of brittle mineral(50%-71%),low content of clay mineral(18%-33%),high porosity(10.8%-26.3%)and good oil-bearing properties(S1 distributed in 3.48-5.64 mg/g,and S1/TOC value in a range of 348-564 oil mg/g).Therefore,the argillaceous dolomite facies was considered the key target series to be explored for the intersalt shale oil in the study area in the coming days.
基金supported by Young Talent fund of University Association for Science and Technology in Shaanxi,China (20210202,to JS)the Science and Technology Innovation Team of Shaanxi (2021TD-32,to ZL).
文摘To date,the genetic transformation system of watermelon has remained inefficient.In this study,the genetic transformation system of watermelon mediated by Agrobacterium tumefaciens was optimized,including different seedling ages,strains of Agrobacterium tumefaciens,concentrations of acetosyringone infected solution,co-culture time,selection pressure of antibiotics timentin and glufosinate,and concentrations of hormones 6-benzylaminopurine,indoleacetic acid and naphthylacetic acid in the corresponding culture medium.Our results suggested that cotyledons would be used as explants,disinfected with 6%sodium hypochlorite for 12 min,cultured for 3 d,and then infected with Agrobacterium inoculum(Agrobacterium EHA105)containing 200μM acetosyringone and 0.02 of final OD_(600).The explants differentiated into adventitious shoots in the medium with 1.5 mg/L 6-benzylaminopurine and 200μM timentin.Positive adventitious shoots were obtained through further screening by 1.4 mg/L herbicide glufosinate-ammonium,and were induced by 0.1 mg/L naphthalene acetic acid into independent plants.Our system improves the genetic transformation efficiency of watermelon and provides a technical basis for continuous acquisition of watermelon transgenic plants.
