Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electro...Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electron microscope, and the effects of the inclusions on the mechanical and corrosion properties of the alloy were investigated. The results indicate that the filtering purification method is effective to remove inclusions in the alloy. By the filtering purification method, the average size of inclusions in the alloy reduces from 12.7 μm to 4.3 μm and the average volume fraction of inclusions in the alloy reduces from 0.26% to 0.06%. The ultimate tensile strength, yield strength and elongation of the alloy are improved from 200 MPa, 156 MPa and 3.4% to 232 MPa, 167 MPa and 7.0%, respectively. The corrosion rate of the alloy decreases dramatically from 38.8g/（mLd） to 2.5 g/（mZ.d） in the salt spray test.展开更多
Coronavirus disease(COVID-19)was first diagnosed in Wuhan in December 2019.The World Health Organization defined the subsequent outbreak of COVID-19 worldwide as a public health emergency of international concern.Epid...Coronavirus disease(COVID-19)was first diagnosed in Wuhan in December 2019.The World Health Organization defined the subsequent outbreak of COVID-19 worldwide as a public health emergency of international concern.Epidemiological data indicate that at least 20%of COVID-19 patients have severe disease.In addition to impairment of the respiratory system,acute kidney injury(AKI)is a major complication.Immune damage mediated by cytokine storms and concomitant AKI is a key factor for poor prognosis.Based on previous experience of blood purification for patients with severe acute respiratory syndrome and Middle East respiratory syndrome combined with clinical front-line practice,we developed a blood purification protocol for patients with severe COVID-19.This protocol is divided into four major steps.The first step is to assess whether patients with severe COVID-19 require blood purification.The second step is to prescribe a blood purification treatment for patients with COVID-19.The third step is to monitor and adjust parameters of blood purification.The fourth step is to evaluate the timing of discontinuation of blood purification.It is expected that blood purification will play a key role in effectively reducing the mortality of patients with severe COVID-19 through the standardized implemenlation of the present protocol.展开更多
基金Project(2007CB613705)supported by the National Basic Research Program of China
文摘Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electron microscope, and the effects of the inclusions on the mechanical and corrosion properties of the alloy were investigated. The results indicate that the filtering purification method is effective to remove inclusions in the alloy. By the filtering purification method, the average size of inclusions in the alloy reduces from 12.7 μm to 4.3 μm and the average volume fraction of inclusions in the alloy reduces from 0.26% to 0.06%. The ultimate tensile strength, yield strength and elongation of the alloy are improved from 200 MPa, 156 MPa and 3.4% to 232 MPa, 167 MPa and 7.0%, respectively. The corrosion rate of the alloy decreases dramatically from 38.8g/（mLd） to 2.5 g/（mZ.d） in the salt spray test.
基金Zhejiang Provincial Science and Tech no logy Department 2019 Provincial Key R&D Program Project(2019C03024).
文摘Coronavirus disease(COVID-19)was first diagnosed in Wuhan in December 2019.The World Health Organization defined the subsequent outbreak of COVID-19 worldwide as a public health emergency of international concern.Epidemiological data indicate that at least 20%of COVID-19 patients have severe disease.In addition to impairment of the respiratory system,acute kidney injury(AKI)is a major complication.Immune damage mediated by cytokine storms and concomitant AKI is a key factor for poor prognosis.Based on previous experience of blood purification for patients with severe acute respiratory syndrome and Middle East respiratory syndrome combined with clinical front-line practice,we developed a blood purification protocol for patients with severe COVID-19.This protocol is divided into four major steps.The first step is to assess whether patients with severe COVID-19 require blood purification.The second step is to prescribe a blood purification treatment for patients with COVID-19.The third step is to monitor and adjust parameters of blood purification.The fourth step is to evaluate the timing of discontinuation of blood purification.It is expected that blood purification will play a key role in effectively reducing the mortality of patients with severe COVID-19 through the standardized implemenlation of the present protocol.
