On the interface of the Cu-Al composite plate from horizontal continuous casting,the eutectic microstructure layer thickness ac-counts for more than 90%of the total interface thickness,and the deformation in rolling f...On the interface of the Cu-Al composite plate from horizontal continuous casting,the eutectic microstructure layer thickness ac-counts for more than 90%of the total interface thickness,and the deformation in rolling forming plays an important role in the quality of the composite plate.The eutectic microstructure material on the interface of the Cu-Al composite plate was prepared by changing the cooling rate of ingot solidification and the deformation in hot compression was investigated.The results show that when the deformation temperature is over 300℃,the softening effect of dynamic recrystallization ofα-Al is greater than the hardening effect,and uniform plastic deformation of eutectic microstructure is caused.The constitutive equation of flow stress in the eutectic microstructure layer was established by Arrhenius hy-perbolic-sine mathematics model,providing a reliable theoretical basis for the deformation of the Cu-Al composite plate.展开更多
Ecological studies suggested a link between air pollution and severe COVID-19 outcomes,while studies accounting for individual-level characteristics are limited.In the present study,we aimed to investigate the impact ...Ecological studies suggested a link between air pollution and severe COVID-19 outcomes,while studies accounting for individual-level characteristics are limited.In the present study,we aimed to investigate the impact of short-term ambient air pollution exposure on disease severity among a cohort of 569 laboratory confirmed COVID-19 patients admitted to designated hospitals in Zhejiang province,China,from January 17 to March 3,2020,and elucidate the possible biological processes involved using transcriptomics.Compared with mild cases,severe cases had higher proportion of medical conditions as well as unfavorable results in most of the laboratory tests,and manifested higher air pollution exposure levels.Higher exposure to air pollutants was associated with increased risk of severe COVID-19 with odds ratio(OR)of 1.89(95%confidence interval(CI):1.01,3.53),2.35(95%CI:1.20,4.61),2.87(95%CI:1.68,4.91),and 2.01(95%CI:1.10,3.69)for PM_(2.5),PM_(10),NO_(2)and CO,respectively.OR for NO_(2)remained significant in two-pollutant models after adjusting for other pollutants.Transcriptional analysis showed 884 differentially expressed genes which mainly were enriched in virus clearance related biological processes between patients with high and low NO_(2)exposure levels,indicating that compromised immune response might be a potential underlying mechanistic pathway.These findings highlight the impact of shortterm air pollution exposure,particularly for NO_(2),on COVID-19 severity,and emphasize the significance in mitigating the COVID-19 burden of commitments to improve air quality.展开更多
The precipitation behaviours during the aging process and the corresponding strengthening mechanism of a Cu-0.4 wt%Sc alloy were systematically investigated in this study.The phase transformation sequence of the preci...The precipitation behaviours during the aging process and the corresponding strengthening mechanism of a Cu-0.4 wt%Sc alloy were systematically investigated in this study.The phase transformation sequence of the precipitation in the aging process of the Cu-0.4 wt%Sc alloy was found to be:supersaturated solid solution→Sc-enriched atomic clusters→metastable phase→Cu4Sc phase.The tetragonal structured lamellar Cu4Sc precipitates,with a habit plane parallel to the{111}plane of the Cu matrix and orientation relationships of(022)_(α)//(211)_(Cu4Sc)and[011]_(α)//[113]_(Cu4Sc),are found homogeneously distributed in the matrix.A combined process of cryogenic rolling(CR)and aging was designed for optimization of the mechanical and electrical properties.Excellent integration of yield strength(696 MPa)and electrical conductivity(62.8%IACS)of this alloy was achieved by cryogenic rolling and subsequent aging process at 400℃for 4 h.The significant precipitation strengthening effect of this alloy is attributed to the Cu4Sc precipitates with an extremely small size of only 1.5–3 nm.The leading strengthening mechanism is considered as the superposition of both coherent strengthening and Orowan strengthening effects.展开更多
Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are at increased risk of acute lung injury.However,it is still not clear wheth...Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are at increased risk of acute lung injury.However,it is still not clear whether this increased risk is related to the usage of renin-angiotensin system(RAS)blockers.We collected medical records of coronavirus disease 2019(COVID-19)patients from the First Affiliated Hospital,Zhejiang University School of Medicine(Hangzhou,China),and evaluated the potential impact of an angiotensin II receptor blocker(ARB)on the clinical outcomes of COVID-19 patients with hypertension.A total of 30 hypertensive COVID-19 patients were enrolled,of which 17 were classified as non-ARB group and the remaining 13 as ARB group based on the antihypertensive therapies they received.Compared with the non-ARB group,patients in the ARB group had a lower proportion of severe cases and intensive care unit(ICU)admission as well as shortened length of hospital stay,and manifested favorable results in most of the laboratory testing.Viral loads in the ARB group were lower than those in the non-ARB group throughout the disease course.No significant difference in the time of seroconversion or antibody levels was observed between the two groups.The median levels of soluble angiotensin-converting enzyme 2(sACE2)in serum and urine samples were similar in both groups,and there were no significant correlations between serum sACE2 and biomarkers of disease severity.Transcriptional analysis showed 125 differentially expressed genes which mainly were enriched in oxygen transport,bicarbonate transport,and blood coagulation.Our results suggest that ARB usage is not associated with aggravation of COVID-19.These findings support the maintenance of ARB treatment in hypertensive patients diagnosed with COVID-19.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(No.2018YFA0707303)the National Natural Science Foundation for Distinguished Young Scholars of China(No.51925401).
文摘On the interface of the Cu-Al composite plate from horizontal continuous casting,the eutectic microstructure layer thickness ac-counts for more than 90%of the total interface thickness,and the deformation in rolling forming plays an important role in the quality of the composite plate.The eutectic microstructure material on the interface of the Cu-Al composite plate was prepared by changing the cooling rate of ingot solidification and the deformation in hot compression was investigated.The results show that when the deformation temperature is over 300℃,the softening effect of dynamic recrystallization ofα-Al is greater than the hardening effect,and uniform plastic deformation of eutectic microstructure is caused.The constitutive equation of flow stress in the eutectic microstructure layer was established by Arrhenius hy-perbolic-sine mathematics model,providing a reliable theoretical basis for the deformation of the Cu-Al composite plate.
基金supported by the National Natural Science Foundation of China (Nos.82072377 and 81971919)。
文摘Ecological studies suggested a link between air pollution and severe COVID-19 outcomes,while studies accounting for individual-level characteristics are limited.In the present study,we aimed to investigate the impact of short-term ambient air pollution exposure on disease severity among a cohort of 569 laboratory confirmed COVID-19 patients admitted to designated hospitals in Zhejiang province,China,from January 17 to March 3,2020,and elucidate the possible biological processes involved using transcriptomics.Compared with mild cases,severe cases had higher proportion of medical conditions as well as unfavorable results in most of the laboratory tests,and manifested higher air pollution exposure levels.Higher exposure to air pollutants was associated with increased risk of severe COVID-19 with odds ratio(OR)of 1.89(95%confidence interval(CI):1.01,3.53),2.35(95%CI:1.20,4.61),2.87(95%CI:1.68,4.91),and 2.01(95%CI:1.10,3.69)for PM_(2.5),PM_(10),NO_(2)and CO,respectively.OR for NO_(2)remained significant in two-pollutant models after adjusting for other pollutants.Transcriptional analysis showed 884 differentially expressed genes which mainly were enriched in virus clearance related biological processes between patients with high and low NO_(2)exposure levels,indicating that compromised immune response might be a potential underlying mechanistic pathway.These findings highlight the impact of shortterm air pollution exposure,particularly for NO_(2),on COVID-19 severity,and emphasize the significance in mitigating the COVID-19 burden of commitments to improve air quality.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-19-012)the National Natural Science Foundation for Distinguished Young Scholars of China(No.51925401)
文摘The precipitation behaviours during the aging process and the corresponding strengthening mechanism of a Cu-0.4 wt%Sc alloy were systematically investigated in this study.The phase transformation sequence of the precipitation in the aging process of the Cu-0.4 wt%Sc alloy was found to be:supersaturated solid solution→Sc-enriched atomic clusters→metastable phase→Cu4Sc phase.The tetragonal structured lamellar Cu4Sc precipitates,with a habit plane parallel to the{111}plane of the Cu matrix and orientation relationships of(022)_(α)//(211)_(Cu4Sc)and[011]_(α)//[113]_(Cu4Sc),are found homogeneously distributed in the matrix.A combined process of cryogenic rolling(CR)and aging was designed for optimization of the mechanical and electrical properties.Excellent integration of yield strength(696 MPa)and electrical conductivity(62.8%IACS)of this alloy was achieved by cryogenic rolling and subsequent aging process at 400℃for 4 h.The significant precipitation strengthening effect of this alloy is attributed to the Cu4Sc precipitates with an extremely small size of only 1.5–3 nm.The leading strengthening mechanism is considered as the superposition of both coherent strengthening and Orowan strengthening effects.
基金supported by the Department of Education of Zhejiang Province(No.Y202043382)the National Natural Science Foundation of China(Nos.82072377 and 81971919)。
文摘Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are at increased risk of acute lung injury.However,it is still not clear whether this increased risk is related to the usage of renin-angiotensin system(RAS)blockers.We collected medical records of coronavirus disease 2019(COVID-19)patients from the First Affiliated Hospital,Zhejiang University School of Medicine(Hangzhou,China),and evaluated the potential impact of an angiotensin II receptor blocker(ARB)on the clinical outcomes of COVID-19 patients with hypertension.A total of 30 hypertensive COVID-19 patients were enrolled,of which 17 were classified as non-ARB group and the remaining 13 as ARB group based on the antihypertensive therapies they received.Compared with the non-ARB group,patients in the ARB group had a lower proportion of severe cases and intensive care unit(ICU)admission as well as shortened length of hospital stay,and manifested favorable results in most of the laboratory testing.Viral loads in the ARB group were lower than those in the non-ARB group throughout the disease course.No significant difference in the time of seroconversion or antibody levels was observed between the two groups.The median levels of soluble angiotensin-converting enzyme 2(sACE2)in serum and urine samples were similar in both groups,and there were no significant correlations between serum sACE2 and biomarkers of disease severity.Transcriptional analysis showed 125 differentially expressed genes which mainly were enriched in oxygen transport,bicarbonate transport,and blood coagulation.Our results suggest that ARB usage is not associated with aggravation of COVID-19.These findings support the maintenance of ARB treatment in hypertensive patients diagnosed with COVID-19.
