[Objective] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province.[Method] The metalaxyl resistance,mating type and isozyme genotype of 292 P. infestans strains...[Objective] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province.[Method] The metalaxyl resistance,mating type and isozyme genotype of 292 P. infestans strains isolated from Guizhou Province were analyzed.[Result] Metalaxyl-resistant P. infestans strains were found in different areas of Guizhou Province. Resistant,moderately resistant and susceptible strains accounted for 35. 62%,33. 90% and 30. 48%,respectively. Both mating types A1 and A2 were found,which accounted for 65. 38% and 34. 62%,respectively. P. infestans strains isolated from Guizhou Province mainly belonged to Gpi genotypes 100 /100 and 100 /100 /111,accounting for 50. 68% and 43. 84%,respectively.[Conclusion]This study provides the theoretical basis for the prevention and control of potato late blight in Guizhou Province.展开更多
The numerical simulation for mold-filling of thin-walled aluminum alloy castings in horizontal traveling magnetic field is performed. A force model of Al alloy melt in the traveling magnetic field is founded by analyz...The numerical simulation for mold-filling of thin-walled aluminum alloy castings in horizontal traveling magnetic field is performed. A force model of Al alloy melt in the traveling magnetic field is founded by analyzing traveling magnetic field carefully. Numerical model of Al alloy mold-filling is founded based on N-S equation, which was suitable for traveling magnetic field. By using acryl glass mold with indium as alloy melt, the experiment testified the filling state of alloy in traveling magnetic field. The results of numerical simulation indicate that the mold-filling ability of gallium melt increases continually with the increase of the input ampere turns.展开更多
The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cultured on different media at different temperatures under natural ...The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cultured on different media at different temperatures under natural light for inducing conidia to explore the optimum isolation technique of single spore and optimum culture condition of conidia. The results showed that the successful isolating rate of single spore from yellow rice false smut balls reached 90. 00% . The sporulation quantities of isolated single spores cultured on PSD and PDB media at 22 - 29 ℃ ( variable temperature under natural light) or 28 ℃ ( constant temperature under dark condition) for 12 d were up to 6. 3 × 107 and 1. 1 × 106 spore / mL,respectively. PSA was the most effective method to isolate single spores from yellow rice false smut balls of U. virens. The optimum conidia culture condition included PSD or PDB medium,22 - 29 ℃ or 28 ℃ ,natural light and vibration culture.展开更多
The bubble migration in liquid titanium alloy melt during vertical centrifugal casting process has been predicted. The effects of different parameters, such as the initial bubble location, the mold rotational speed an...The bubble migration in liquid titanium alloy melt during vertical centrifugal casting process has been predicted. The effects of different parameters, such as the initial bubble location, the mold rotational speed and the mold rotational direction on the bubble in the migration process are investigated. The results show that the bubble migration can be divided into the radial movement to the mould rotation axis and the circular movement to the mould wall opposite to rotational direction of the casting mould. The casting mould wall has an impeditive effect on the circular movement of the bubble during its migration process. And the bubble finally migrates like a straight line along the mould wall located at the opposite direction of the rotational casting mould whether it rotates clockwise or anti-clockwise. The bubbles at the position near the mould wall located at the opposite direction of the rotational casting mould are much easier to migrate in a straight line. The instantaneous speed of the gas bubble increases with the increment of the mould rotational speed. However the mould rotational speed is high or low, the moving speed of the gas bubble increases slightly at the primary stage, and then decreases gradually like a ladder.展开更多
The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy a...The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy alloys(HEAs)were explored.Results show that the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs are composed of face-centered cubic and body-centered cubic(BCC)phases.As W content increases,the microstructure changes from eutectic to dendritic.The addition of W lowers the nucleation barrier of the BCC phase,decreases the valence electron concentration of the HEAs,and replaces Al in the BCC phase,thus facilitating the nucleation of the BCC phase.Tensile results show that the addition of W greatly improves the mechanical properties,and solid-solution,heterogeneous-interface,and second-phase strengthening are the main strengthening mechanisms.The yield strength,tensile strength,and elongation of the Al_(1.25)CoCrFeNi2.95W0.05 HEA are 601.44 MPa,1132.26 MPa,and 15.94%,respectively,realizing a balance between strength and plasti-city.The fracture mode of the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs is ductile–brittle mixed fracture,and the crack propagates and initiates in the BCC phase.The eutectic lamellar structure impedes crack propagation and maintains plasticity.展开更多
基金Supported by Agricultural Science and Technology Project of Guizhou Province in 2011([2011]3022)
文摘[Objective] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province.[Method] The metalaxyl resistance,mating type and isozyme genotype of 292 P. infestans strains isolated from Guizhou Province were analyzed.[Result] Metalaxyl-resistant P. infestans strains were found in different areas of Guizhou Province. Resistant,moderately resistant and susceptible strains accounted for 35. 62%,33. 90% and 30. 48%,respectively. Both mating types A1 and A2 were found,which accounted for 65. 38% and 34. 62%,respectively. P. infestans strains isolated from Guizhou Province mainly belonged to Gpi genotypes 100 /100 and 100 /100 /111,accounting for 50. 68% and 43. 84%,respectively.[Conclusion]This study provides the theoretical basis for the prevention and control of potato late blight in Guizhou Province.
文摘The numerical simulation for mold-filling of thin-walled aluminum alloy castings in horizontal traveling magnetic field is performed. A force model of Al alloy melt in the traveling magnetic field is founded by analyzing traveling magnetic field carefully. Numerical model of Al alloy mold-filling is founded based on N-S equation, which was suitable for traveling magnetic field. By using acryl glass mold with indium as alloy melt, the experiment testified the filling state of alloy in traveling magnetic field. The results of numerical simulation indicate that the mold-filling ability of gallium melt increases continually with the increase of the input ampere turns.
基金Science and Technology Project of Guizhou Province[QKH Major Project( 2012 ) 6012 ]Supported by Science and Technology Fund of Guizhou Province ( QKH J[2009]2103)+1 种基金Science and Technology Research Programof Guizhou Province ( QKH NY[2012]3031)Project of Guizhou Academy of Agricultural Sciences ( [2010]033 and QNKH[Major]07016)
文摘The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cultured on different media at different temperatures under natural light for inducing conidia to explore the optimum isolation technique of single spore and optimum culture condition of conidia. The results showed that the successful isolating rate of single spore from yellow rice false smut balls reached 90. 00% . The sporulation quantities of isolated single spores cultured on PSD and PDB media at 22 - 29 ℃ ( variable temperature under natural light) or 28 ℃ ( constant temperature under dark condition) for 12 d were up to 6. 3 × 107 and 1. 1 × 106 spore / mL,respectively. PSA was the most effective method to isolate single spores from yellow rice false smut balls of U. virens. The optimum conidia culture condition included PSD or PDB medium,22 - 29 ℃ or 28 ℃ ,natural light and vibration culture.
基金Sponsored by the National Natural Science Foundation of China(Grant No.U1604254)the Initial Scientific Research Fund of Young Teachers in Henan University of Technology(Grant No.2013BS050)
文摘The bubble migration in liquid titanium alloy melt during vertical centrifugal casting process has been predicted. The effects of different parameters, such as the initial bubble location, the mold rotational speed and the mold rotational direction on the bubble in the migration process are investigated. The results show that the bubble migration can be divided into the radial movement to the mould rotation axis and the circular movement to the mould wall opposite to rotational direction of the casting mould. The casting mould wall has an impeditive effect on the circular movement of the bubble during its migration process. And the bubble finally migrates like a straight line along the mould wall located at the opposite direction of the rotational casting mould whether it rotates clockwise or anti-clockwise. The bubbles at the position near the mould wall located at the opposite direction of the rotational casting mould are much easier to migrate in a straight line. The instantaneous speed of the gas bubble increases with the increment of the mould rotational speed. However the mould rotational speed is high or low, the moving speed of the gas bubble increases slightly at the primary stage, and then decreases gradually like a ladder.
基金supported by the National Natural Science Foundation of China(No.51825401)the China Postdoctoral Science Foundation(No.2023TO0099)the Interdisciplinary Research Foundation of Harbin Institute of Technology.
文摘The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy alloys(HEAs)were explored.Results show that the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs are composed of face-centered cubic and body-centered cubic(BCC)phases.As W content increases,the microstructure changes from eutectic to dendritic.The addition of W lowers the nucleation barrier of the BCC phase,decreases the valence electron concentration of the HEAs,and replaces Al in the BCC phase,thus facilitating the nucleation of the BCC phase.Tensile results show that the addition of W greatly improves the mechanical properties,and solid-solution,heterogeneous-interface,and second-phase strengthening are the main strengthening mechanisms.The yield strength,tensile strength,and elongation of the Al_(1.25)CoCrFeNi2.95W0.05 HEA are 601.44 MPa,1132.26 MPa,and 15.94%,respectively,realizing a balance between strength and plasti-city.The fracture mode of the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs is ductile–brittle mixed fracture,and the crack propagates and initiates in the BCC phase.The eutectic lamellar structure impedes crack propagation and maintains plasticity.
