Compared with H13 steel, the influences of different heat treatment process on the microstructure and properties of the new type of hot working die steel H13MOD were studied. The results show that the complete aus ten...Compared with H13 steel, the influences of different heat treatment process on the microstructure and properties of the new type of hot working die steel H13MOD were studied. The results show that the complete aus tenitizing temperature of H13MOD is around 1030 ℃ and the quenching hardness achieves the maximum value at this temperature. While for H13, the complete austenitizing temperature is above 1100 ℃ and the quenching hardness rise constantly with the quenching temperature increasing. In quenching process, the undissolved MC carbides can prevent the coarsening of grain in both steels. With the rise of quenching temperature, when MC carbides dissolve completely, the grain grows quickly. The hardness and strength of H13MOD at higher tempering temperature （above 570 ℃） are nearly the same as those of H13, but its toughness is higher than that of H13. Mo2C carbide is the main strengthening phase in H13MOD, which is attributed to the higher content of Mo. The quantity of VC eutectic car- bides is reduced because of lower content of V in H13MOD, which plays an important role in enhancing the impact toughness of H13MOD. Under a certain strength condition, H13MOD steel can be used in the environment that higher toughness is required and the service life of die casting mold can be improved.展开更多
Objective:To investigate the impact of the preinduced intestinal heat shock protein 70(HSP70)on the visceral hypersensitivity and abnormal intestinal motility in a post-infectious irritable bowel syndrome(PI-IBS) mous...Objective:To investigate the impact of the preinduced intestinal heat shock protein 70(HSP70)on the visceral hypersensitivity and abnormal intestinal motility in a post-infectious irritable bowel syndrome(PI-IBS) mouse model.Methods:Eighty-four female C57BL/6 mice were randomly assigned to four groups:control group(n=21) and induction+PI-IBS group(n=21),PI-IBS group(n=21) and induction group(n=21).The mice in PI-IBS group were infected in vivo with trichinella spiralis by oral administration.The visceral hypersensitivity and intestinal motility were evaluated respectively with abdominal withdrawal reflex and colon transportation test.The intestinal HSP70 protein and mRNA level was measured by Western blot and realtime PCR.Meanwhile,the intestinal proinflammatory cytokines IL-10 and TNF-α level was detected by ELISA.Results:Compared with their counterparts in PI-IBS group,the animals in the Induction+PI-IBS group show significantly increased intestinal level of HSP70 and obviously ameliorative clinical tigurcs.including abdominal withdrawal reflex score,intestine transportation time and Bristol scores(P<0.05).Meanwhile,the intestinal post-inflammatory cytokines remarkably changed,including increased IL-10 level and decreased TNF-αlevel(P<0.05).Conclusions:Intestinal IISP70 may play a potential protective role through improving the imbalance between the intestinal post-inflammatory and anti-inflammatory cytokines in PI-IBS.展开更多
文摘Compared with H13 steel, the influences of different heat treatment process on the microstructure and properties of the new type of hot working die steel H13MOD were studied. The results show that the complete aus tenitizing temperature of H13MOD is around 1030 ℃ and the quenching hardness achieves the maximum value at this temperature. While for H13, the complete austenitizing temperature is above 1100 ℃ and the quenching hardness rise constantly with the quenching temperature increasing. In quenching process, the undissolved MC carbides can prevent the coarsening of grain in both steels. With the rise of quenching temperature, when MC carbides dissolve completely, the grain grows quickly. The hardness and strength of H13MOD at higher tempering temperature （above 570 ℃） are nearly the same as those of H13, but its toughness is higher than that of H13. Mo2C carbide is the main strengthening phase in H13MOD, which is attributed to the higher content of Mo. The quantity of VC eutectic car- bides is reduced because of lower content of V in H13MOD, which plays an important role in enhancing the impact toughness of H13MOD. Under a certain strength condition, H13MOD steel can be used in the environment that higher toughness is required and the service life of die casting mold can be improved.
基金supported by Natural Science Foundation of China Grant(No.81160057):International Science and Technique Corporation Foundation of Hainan Province Grant(No.KJHZ2013-14)
文摘Objective:To investigate the impact of the preinduced intestinal heat shock protein 70(HSP70)on the visceral hypersensitivity and abnormal intestinal motility in a post-infectious irritable bowel syndrome(PI-IBS) mouse model.Methods:Eighty-four female C57BL/6 mice were randomly assigned to four groups:control group(n=21) and induction+PI-IBS group(n=21),PI-IBS group(n=21) and induction group(n=21).The mice in PI-IBS group were infected in vivo with trichinella spiralis by oral administration.The visceral hypersensitivity and intestinal motility were evaluated respectively with abdominal withdrawal reflex and colon transportation test.The intestinal HSP70 protein and mRNA level was measured by Western blot and realtime PCR.Meanwhile,the intestinal proinflammatory cytokines IL-10 and TNF-α level was detected by ELISA.Results:Compared with their counterparts in PI-IBS group,the animals in the Induction+PI-IBS group show significantly increased intestinal level of HSP70 and obviously ameliorative clinical tigurcs.including abdominal withdrawal reflex score,intestine transportation time and Bristol scores(P<0.05).Meanwhile,the intestinal post-inflammatory cytokines remarkably changed,including increased IL-10 level and decreased TNF-αlevel(P<0.05).Conclusions:Intestinal IISP70 may play a potential protective role through improving the imbalance between the intestinal post-inflammatory and anti-inflammatory cytokines in PI-IBS.
