To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray dif...To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and micro-property.The samples with deformation rate of 0-5.59%or annealing at 550℃ are analyzed.The results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled samples.With the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of samples.However,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone property.The cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.展开更多
Objective: This study was conducted to determine the effect of the application of cold on hematoma,ecchymosis,and pain in patients undergoing percutaneous coronary intervention.Methods: It is a quasi-experimental stud...Objective: This study was conducted to determine the effect of the application of cold on hematoma,ecchymosis,and pain in patients undergoing percutaneous coronary intervention.Methods: It is a quasi-experimental study with a control group.A total of 200 patients (100 in the control group and 100 in the experimental group) were included in the research.In the experimental group,a cold pack was applied to the bottom of the sandbag for the first 15 min after withdrawing the femoral arterial catheter.Both groups were assessed and followed up at the first 15th minute and 4th,48th and 72 nd h.Results: After the femoral arterial catheter was withdrawn,ecchymosis and hematoma were smaller and pain was less in the experimental group at the catheter entry site compared to the control group,and the difference was statistically significant (P < 0.01).Conclusion: It was determined that the application of cold reduced the formation of hematomas,ecchymoses and pain in patients after the withdrawal of the femoral arterial catheter.展开更多
SiC porous ceramics were prepared at 1 400 ℃ for4 h with crystalline silicon cutting waste and activated carbon as main starting materials and NH4HCO3 as the pore-forming agent. Effects of NH4HCO3 additions( 0,20%,30...SiC porous ceramics were prepared at 1 400 ℃ for4 h with crystalline silicon cutting waste and activated carbon as main starting materials and NH4HCO3 as the pore-forming agent. Effects of NH4HCO3 additions( 0,20%,30%,40%,by mass) on the phase composition,microstructure,sintering properties,cold compressive strength and thermal shock resistance of as-prepared Si C porous ceramics were investigated. The results show that:( 1) addition of NH4HCO3 remarkably influences the apparent porosity and cold compressive strength of specimens. The apparent porosity achieves its maximum value( 63. 40%) when 40% NH4HCO3 is added,while the minimum cold compressive strength is 4. 77 MPa;( 2) the specimen with 40% NH4HCO3 has the best thermal shock resistance. The thermal cycling times between1 000 ℃ to room temperature reach 62;( 3) the addition of NH4HCO3 does not remarkably affect the phase composition of the specimens;( 4) the specimens include a large number of SiC particles and a small amount of SiC whiskers.展开更多
基金support from Guangxi Science and Technology Major Project of China(Grant No.AA18242012-1).
文摘To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and micro-property.The samples with deformation rate of 0-5.59%or annealing at 550℃ are analyzed.The results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled samples.With the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of samples.However,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone property.The cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.
基金The author(s)disclosed receipt of the following financial support for the research,authorship,and/or publication of this article:This study was supported by the Scientific Research Projects Commission of the Ataturk University Scientific Research Projects unit(Project No.2011/55).
文摘Objective: This study was conducted to determine the effect of the application of cold on hematoma,ecchymosis,and pain in patients undergoing percutaneous coronary intervention.Methods: It is a quasi-experimental study with a control group.A total of 200 patients (100 in the control group and 100 in the experimental group) were included in the research.In the experimental group,a cold pack was applied to the bottom of the sandbag for the first 15 min after withdrawing the femoral arterial catheter.Both groups were assessed and followed up at the first 15th minute and 4th,48th and 72 nd h.Results: After the femoral arterial catheter was withdrawn,ecchymosis and hematoma were smaller and pain was less in the experimental group at the catheter entry site compared to the control group,and the difference was statistically significant (P < 0.01).Conclusion: It was determined that the application of cold reduced the formation of hematomas,ecchymoses and pain in patients after the withdrawal of the femoral arterial catheter.
文摘SiC porous ceramics were prepared at 1 400 ℃ for4 h with crystalline silicon cutting waste and activated carbon as main starting materials and NH4HCO3 as the pore-forming agent. Effects of NH4HCO3 additions( 0,20%,30%,40%,by mass) on the phase composition,microstructure,sintering properties,cold compressive strength and thermal shock resistance of as-prepared Si C porous ceramics were investigated. The results show that:( 1) addition of NH4HCO3 remarkably influences the apparent porosity and cold compressive strength of specimens. The apparent porosity achieves its maximum value( 63. 40%) when 40% NH4HCO3 is added,while the minimum cold compressive strength is 4. 77 MPa;( 2) the specimen with 40% NH4HCO3 has the best thermal shock resistance. The thermal cycling times between1 000 ℃ to room temperature reach 62;( 3) the addition of NH4HCO3 does not remarkably affect the phase composition of the specimens;( 4) the specimens include a large number of SiC particles and a small amount of SiC whiskers.
