[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, mor...[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, morphological characteristics and main agronomic characters of male sterility character of 4 kinds of barley male sterility materials 2001 - 17, 2001 - 37, 2001 - 84 and 2001 - 116 and their dedved lines were observed and researched.[ Result] Barley male sterility existed genetic phenomenon of single dominant nuclear gene caused by environmental stimulation, its sterility controlled by MS, the sterile genotype was MSms. There was stable nucleo-cytoplasmic inheritance on barley male sterility which was controlled by cytoplasmic mate sterile gene S and nuclear gene rr, and its genotype was S（rr）, this male sterility belonged to CMS type sterility. Temperature had no effect on fertility. [ Conclusion] There was stable nucleo-cytoplasmic inheritance on barley male sterility, this result played a positively promoting role in barley practical production.展开更多
The solidification process of metals plays a critical role in their final microstructure and, correspondingly, in their performance. It is therefore important to probe the solidification behavior of metals using advan...The solidification process of metals plays a critical role in their final microstructure and, correspondingly, in their performance. It is therefore important to probe the solidification behavior of metals using advanced in situ techniques. Synchrotron radiation X-ray imaging is one of the most powerful techniques to observe the solidification process of metals directly. Here, we review the development of the solidification apparatus, including the directional solidification device, resistance furnace, multi-field coupling device, semisolid forming device, aerodynamic levitation apparatus, and laser additive manufacturing apparatus. We highlight the recent research progress on the use of synchrotron radiation X-ray imaging to reveal the solidification behavior of metals in the above circumstances. The future perspectives of synchrotron radiation X-ray imaging in metal research are discussed. Further development of this technique will contribute to improve the understanding of the solidification process of metals and other types of materials at different scales.展开更多
This paper focuses on work related to post irradiation examination of 300-series austenitic stainless steel taken from reactor vessel internals of PWR. High neutron irradiation dose in NNP＇s leads to a degradation of...This paper focuses on work related to post irradiation examination of 300-series austenitic stainless steel taken from reactor vessel internals of PWR. High neutron irradiation dose in NNP＇s leads to a degradation of microstructure of the material in a nano-metric scale. Hence, it is important to characterize the irradiated materials to understand the physical basis of the degradation mechanisms. Microstructural characterization of neutron-irradiated materials by TEM requires enhanced sample preparation methodologies, which commonly needs general improvements regarding particular experiment to be performed. In this study, the authors have developed methodology specialized in 1 mm TEM thin foil preparation from a deformed shank of a broken miniaturized tensile specimen. TEM foil size in current studies is smaller than standard because of the small shank diameter and high radioactivity of the studied material. The reduction of the TEM foil radioactivity to minimum is crucial to perform EDX chemical analysis and to increase the EDX detector lifetime. This paper describes whole process from bulk sample handling, including remote-controlled material cutting in shielded hot-cells and disc polishing in glow-boxes, up to the final procedure of electrolytic-polishing of electron transparent 1 mm TEM foils. Eventually, results of TEM microanalysis of radiation-induced defects were present.展开更多
A two-phase numerical model coupled with heat transfer was presented to describe the radial distribution of SiC particles on centrifugally-cast metal matrix composite,and a transverse static magnetic field was concurr...A two-phase numerical model coupled with heat transfer was presented to describe the radial distribution of SiC particles on centrifugally-cast metal matrix composite,and a transverse static magnetic field was concurrently imposed to induce electromagnetic stirring of the melt as it revolved with the mold.Meanwhile,experimental observations were also carried out to examine the radial distribution of SiC particles in pure aluminum.The effects of the imposed magnetic field,particle size and the matrix metals were discussed.The computational results show that the particles tend to be congregated by the centrifugal force,and both increasing the imposed magnetic field and decreasing the particle size tend to result in even distribution of the particles.With the magnetic field varying from 0 to 1 T and the particle size from 550 to 180 μm,a uniform distribution of the particles in the aluminum matrix can be obtained among the computational results.The matrix metal can also influence the particle distributions due to the difference in physical properties of metals.Experimental observation shows similar tendency of particle distributions in aluminum matrix influenced by magnetic field and particle size.However,the chilling effect from the mold wall results in an outer particle-free zone,which is not involved in the numerical model.展开更多
Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing system.The...Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing system.The metallurgraphs of the fracture section of the specimens were also experimentally observed and analyzed for exploring their failure mechanism under different temperatures and heating rates.The results show that the higher the temperature,the lower the ultimate strength of the specimens.And the higher the heating rate,the higher the ultimate strength of the specimens.The high temperatures and high heating rates will induce microvoids in the specimens which make the specimens failure under relatively low loads.展开更多
基金Supported by National Natural Science Foundation of Inner Mongolia(200711020307)Public Industry ( Agriculture)Specific Re-search Program of Ministry of Agriculture (nyhyzx07-010)~~
文摘[Objective] The aim was to research the genetic mechanism of barley male sterility, and provide the theoretical reference for breeding strong heterosis hybrid of barley. [ Method] Fertility segregation phenomenon, morphological characteristics and main agronomic characters of male sterility character of 4 kinds of barley male sterility materials 2001 - 17, 2001 - 37, 2001 - 84 and 2001 - 116 and their dedved lines were observed and researched.[ Result] Barley male sterility existed genetic phenomenon of single dominant nuclear gene caused by environmental stimulation, its sterility controlled by MS, the sterile genotype was MSms. There was stable nucleo-cytoplasmic inheritance on barley male sterility which was controlled by cytoplasmic mate sterile gene S and nuclear gene rr, and its genotype was S（rr）, this male sterility belonged to CMS type sterility. Temperature had no effect on fertility. [ Conclusion] There was stable nucleo-cytoplasmic inheritance on barley male sterility, this result played a positively promoting role in barley practical production.
基金supported by the National Natural Science Foundation of China for Excellent Young Scholars(No.51922068)the National Natural Science Foundation of China(Nos.51821001,51904186)the fund of the State Key Laboratory of Solidification Processing in NWPU,China(No.SKLSP202102)。
文摘The solidification process of metals plays a critical role in their final microstructure and, correspondingly, in their performance. It is therefore important to probe the solidification behavior of metals using advanced in situ techniques. Synchrotron radiation X-ray imaging is one of the most powerful techniques to observe the solidification process of metals directly. Here, we review the development of the solidification apparatus, including the directional solidification device, resistance furnace, multi-field coupling device, semisolid forming device, aerodynamic levitation apparatus, and laser additive manufacturing apparatus. We highlight the recent research progress on the use of synchrotron radiation X-ray imaging to reveal the solidification behavior of metals in the above circumstances. The future perspectives of synchrotron radiation X-ray imaging in metal research are discussed. Further development of this technique will contribute to improve the understanding of the solidification process of metals and other types of materials at different scales.
文摘This paper focuses on work related to post irradiation examination of 300-series austenitic stainless steel taken from reactor vessel internals of PWR. High neutron irradiation dose in NNP＇s leads to a degradation of microstructure of the material in a nano-metric scale. Hence, it is important to characterize the irradiated materials to understand the physical basis of the degradation mechanisms. Microstructural characterization of neutron-irradiated materials by TEM requires enhanced sample preparation methodologies, which commonly needs general improvements regarding particular experiment to be performed. In this study, the authors have developed methodology specialized in 1 mm TEM thin foil preparation from a deformed shank of a broken miniaturized tensile specimen. TEM foil size in current studies is smaller than standard because of the small shank diameter and high radioactivity of the studied material. The reduction of the TEM foil radioactivity to minimum is crucial to perform EDX chemical analysis and to increase the EDX detector lifetime. This paper describes whole process from bulk sample handling, including remote-controlled material cutting in shielded hot-cells and disc polishing in glow-boxes, up to the final procedure of electrolytic-polishing of electron transparent 1 mm TEM foils. Eventually, results of TEM microanalysis of radiation-induced defects were present.
基金Project supported by Scientific and Technological Research Program for Universities,Liaoning Province,China
文摘A two-phase numerical model coupled with heat transfer was presented to describe the radial distribution of SiC particles on centrifugally-cast metal matrix composite,and a transverse static magnetic field was concurrently imposed to induce electromagnetic stirring of the melt as it revolved with the mold.Meanwhile,experimental observations were also carried out to examine the radial distribution of SiC particles in pure aluminum.The effects of the imposed magnetic field,particle size and the matrix metals were discussed.The computational results show that the particles tend to be congregated by the centrifugal force,and both increasing the imposed magnetic field and decreasing the particle size tend to result in even distribution of the particles.With the magnetic field varying from 0 to 1 T and the particle size from 550 to 180 μm,a uniform distribution of the particles in the aluminum matrix can be obtained among the computational results.The matrix metal can also influence the particle distributions due to the difference in physical properties of metals.Experimental observation shows similar tendency of particle distributions in aluminum matrix influenced by magnetic field and particle size.However,the chilling effect from the mold wall results in an outer particle-free zone,which is not involved in the numerical model.
基金Projects(10872221,50621403)supported by the National Natural Science Foundation of China
文摘Effects of temperature and heating rate on the mechanical properties of the tensile specimens of magnesium alloy AZ31 were experimentally investigated using a Gleeble-1500 thermo-mechanical material testing system.The metallurgraphs of the fracture section of the specimens were also experimentally observed and analyzed for exploring their failure mechanism under different temperatures and heating rates.The results show that the higher the temperature,the lower the ultimate strength of the specimens.And the higher the heating rate,the higher the ultimate strength of the specimens.The high temperatures and high heating rates will induce microvoids in the specimens which make the specimens failure under relatively low loads.
