In the present investigation, a pipe inner-surface grinding（PISG） technique was developed to fabricate nanostructure in the inner-surface of an austenitic 304 stainless steel pipe. PISG was performed by high speed s...In the present investigation, a pipe inner-surface grinding（PISG） technique was developed to fabricate nanostructure in the inner-surface of an austenitic 304 stainless steel pipe. PISG was performed by high speed shearing with hard sphere tips, leading to gradient distribution of strain, strain rate and strain gradient along depth. Nano-austenite with an average boundary spacing of 20 nm was generated, followed by deformation microstructure characterized by shear bands, multi-and uni-directional twins and planar dislocation arrays. Deformation induced grain refinement of austenitic 304 stainless steel with low stacking fault energy（SFE） covering 4–5 order＇s magnitude of length scales toward nanometer regime was unified.展开更多
A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room tempera...A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room temperature,and the principle of the method was provided.Experiments and FE simulations were carried out to analyze the deformation characteristics for the part with larger variable diameter ratio(35%).The results show that visco-elasto-plastic pressure-carrying medium can meet the requirements of the room-temperature deformation condition for nickel based super-alloy sheet.The inner and outer pressure forming with the visco-elasto-plastic pressure-carrying medium can meet the requirements of dimensional accuracy for the thin-walled part with variable diameter sections.The thinning of wall-thickness is less than 4%.This method provides a new approach for near-net shape forming of nickel based super-alloy thin-walled parts with variable diameter sections.展开更多
The results from this study showed that the thresholds of brainstem auditory-evoked potentials peak following 10 successive days of intramuscular injection of Roman chickens with kanamycin, starting 3 days after birth...The results from this study showed that the thresholds of brainstem auditory-evoked potentials peak following 10 successive days of intramuscular injection of Roman chickens with kanamycin, starting 3 days after birth. Fluorescence immunohistochemistry analysis revealed few ganglion cells positively labeled for Ephrin A2 in the cochlea of experimental chickens from 2 days before until 7 days after the last kanamycin injection. The number of Ephrin A2-positive ganglion cell bodies was increased at 15 days after the last injection and was similar to that in normal chickens at 30 days following the cessation of kanamycin treatment. These experimental findings indicate that Ephrin A2 protein expression in the acoustic ganglia is synchronized with the connection damage and regeneration of cochlear hair cells after kanamycin exposure. Ephrin A2 may play an important role in the regeneration and plasticity of cochlear hair cells in the chick cochlea following kanamycin ototoxicity.展开更多
基金supported financially by the Hundred Outstanding Creative Talents Projects in University of Hebei ProvinceChina, the Project Program of Heavy Machinery Collaborative Innovation Center+1 种基金the Natural Science Foundation of Hebei Province, China (No. E2018203312)the Postdoctoral Science Foundation of Hebei Province, China
文摘In the present investigation, a pipe inner-surface grinding（PISG） technique was developed to fabricate nanostructure in the inner-surface of an austenitic 304 stainless steel pipe. PISG was performed by high speed shearing with hard sphere tips, leading to gradient distribution of strain, strain rate and strain gradient along depth. Nano-austenite with an average boundary spacing of 20 nm was generated, followed by deformation microstructure characterized by shear bands, multi-and uni-directional twins and planar dislocation arrays. Deformation induced grain refinement of austenitic 304 stainless steel with low stacking fault energy（SFE） covering 4–5 order＇s magnitude of length scales toward nanometer regime was unified.
文摘A novel forming method of nickel based super-alloy thin-walled part with variable diameter sections was proposed by using inner and outer pressure with the visco-elasto-plastic pressure-carrying medium at room temperature,and the principle of the method was provided.Experiments and FE simulations were carried out to analyze the deformation characteristics for the part with larger variable diameter ratio(35%).The results show that visco-elasto-plastic pressure-carrying medium can meet the requirements of the room-temperature deformation condition for nickel based super-alloy sheet.The inner and outer pressure forming with the visco-elasto-plastic pressure-carrying medium can meet the requirements of dimensional accuracy for the thin-walled part with variable diameter sections.The thinning of wall-thickness is less than 4%.This method provides a new approach for near-net shape forming of nickel based super-alloy thin-walled parts with variable diameter sections.
基金supported by the Natural Science Foundation of Shanghai,No.08ZR1414900 and 11ZR1423600
文摘The results from this study showed that the thresholds of brainstem auditory-evoked potentials peak following 10 successive days of intramuscular injection of Roman chickens with kanamycin, starting 3 days after birth. Fluorescence immunohistochemistry analysis revealed few ganglion cells positively labeled for Ephrin A2 in the cochlea of experimental chickens from 2 days before until 7 days after the last kanamycin injection. The number of Ephrin A2-positive ganglion cell bodies was increased at 15 days after the last injection and was similar to that in normal chickens at 30 days following the cessation of kanamycin treatment. These experimental findings indicate that Ephrin A2 protein expression in the acoustic ganglia is synchronized with the connection damage and regeneration of cochlear hair cells after kanamycin exposure. Ephrin A2 may play an important role in the regeneration and plasticity of cochlear hair cells in the chick cochlea following kanamycin ototoxicity.
