To study the influence of texture on Hall-Petch slope,the Hall-Petch relationships of two hot-extruded AZ31 alloys(A117 and A189)were determined by the measurement of yield strength at room temperature.To determine th...To study the influence of texture on Hall-Petch slope,the Hall-Petch relationships of two hot-extruded AZ31 alloys(A117 and A189)were determined by the measurement of yield strength at room temperature.To determine the real texture difference,the texture changes were facilitated by the variation of extrusion ratio and demonstrated by the actual grain orientation distributions.The A117 alloys exhibited higher Hall-Petch slope in comparison of A187 in the condition of tension and compression,because A117 alloys had lower volume fraction of grains in the range of basal pole 75°-90°.The Hall-Petch slope differences for both alloys were analyzed and discussed by boundary obstacle against deformation propagation in grains with various orientation.Due to the higher volume fraction of grains in the range of basal pole 75°-90°in A189,the effect of hindering dislocation slip or twinning propagation by grains boundary was weaker than of A117.展开更多
To produce high strength and ductility Mg alloys with high productivity and low energy consumption,the residual heat rolling (RHR) process was initially proposed.The microstucture and mechanical properties of AZ31 pro...To produce high strength and ductility Mg alloys with high productivity and low energy consumption,the residual heat rolling (RHR) process was initially proposed.The microstucture and mechanical properties of AZ31 processed by RHR were investigated by optical micrscopy (OM),electron backscatter diffraction (EBSD),and electron universal testing machine.The yield strength (YS),ultimate tensile strength (UTS),and elongation to failure of RHRed AZ31 sheet were 194 MPa,311 MPa,and 22%,respectively.The RHRed AZ31 alloys after annealing have very fine and homogeneous grains.The symmetrical rolled (SR) and RHRed AZ31 exhibit typical {0002} basal textures.The RHRed AZ31 has double-peak basal texture distribution.The basal poles of RHRed AZ31 split from normal direction (ND) to rolling direction (RD).There are few hard orientation distributions on the basal slip and more soft orientation distributions on the prismatic slip in the RHRed AZ31 sheets than those in the SRed AZ31sheets.展开更多
The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A total of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts o...The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A total of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts of the digestive tube, mainly belong to the genera Photobacterium, Bacillus, Pseudomonas Vibrio and some genera of the family Enterobacteriaceae. There are significantly more varieties of bacteria in crop than in stomach and intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera, such as Bacillus and Photobacterium, are the same as those in the digestive tube, but greatly differ in percentages. The number of heterotrophic bacteria and Vibrio in rearing shoal change in line with the alteration of the temperature, and are significantly affected by the use of pesticides.展开更多
基金Funded by the National Natural Science Foundation of China(No.51271046)the Liaoning Science and Technology Joint Fund(Nos.2020-YKLH-26 and 2021-YKLH-19)+3 种基金the Liaoning Science and Technology Projects(No.20180550724)the Foundation of Liaoning Key Laboratory of Chemical Additive Synthesis and Separation(No.ZJNK2109)the Doctoral Business and Innovation Launching Plan of Ying Kou City(No.QB-2019-10)the HighLevel Talent Research Startup Foundation of Yingkou Institute of Technology(Nos.YJRC202008 and YJRC202009)。
文摘To study the influence of texture on Hall-Petch slope,the Hall-Petch relationships of two hot-extruded AZ31 alloys(A117 and A189)were determined by the measurement of yield strength at room temperature.To determine the real texture difference,the texture changes were facilitated by the variation of extrusion ratio and demonstrated by the actual grain orientation distributions.The A117 alloys exhibited higher Hall-Petch slope in comparison of A187 in the condition of tension and compression,because A117 alloys had lower volume fraction of grains in the range of basal pole 75°-90°.The Hall-Petch slope differences for both alloys were analyzed and discussed by boundary obstacle against deformation propagation in grains with various orientation.Due to the higher volume fraction of grains in the range of basal pole 75°-90°in A189,the effect of hindering dislocation slip or twinning propagation by grains boundary was weaker than of A117.
基金Funded by the National Natural Science Foundation of China (51271046)the Liaoning Science and Technology Joint Fund (2020-YKLH-26)+3 种基金the Liaoning Science and Technology Projects(20180550724)the Educational Department of Liaoning Province Science and Technology Projects(L2019002, L2019008)the National Students’ Program for Innovation and Entrepreneurship Training (201914435050)the Doctoral Business and Innovation Launching Plan of Ying Kou City (QB-2019-10)。
文摘To produce high strength and ductility Mg alloys with high productivity and low energy consumption,the residual heat rolling (RHR) process was initially proposed.The microstucture and mechanical properties of AZ31 processed by RHR were investigated by optical micrscopy (OM),electron backscatter diffraction (EBSD),and electron universal testing machine.The yield strength (YS),ultimate tensile strength (UTS),and elongation to failure of RHRed AZ31 sheet were 194 MPa,311 MPa,and 22%,respectively.The RHRed AZ31 alloys after annealing have very fine and homogeneous grains.The symmetrical rolled (SR) and RHRed AZ31 exhibit typical {0002} basal textures.The RHRed AZ31 has double-peak basal texture distribution.The basal poles of RHRed AZ31 split from normal direction (ND) to rolling direction (RD).There are few hard orientation distributions on the basal slip and more soft orientation distributions on the prismatic slip in the RHRed AZ31 sheets than those in the SRed AZ31sheets.
文摘The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A total of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts of the digestive tube, mainly belong to the genera Photobacterium, Bacillus, Pseudomonas Vibrio and some genera of the family Enterobacteriaceae. There are significantly more varieties of bacteria in crop than in stomach and intestine. A total of 173 strains of bacteria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera, such as Bacillus and Photobacterium, are the same as those in the digestive tube, but greatly differ in percentages. The number of heterotrophic bacteria and Vibrio in rearing shoal change in line with the alteration of the temperature, and are significantly affected by the use of pesticides.
