During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest...During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.展开更多
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi...In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.展开更多
Background:Second primary malignancies(SPMs)account for over 30%of total deaths in head and neck cancer(HNC)patients.The increasing use of radiotherapy raises concerns about the elevated risk of radiation-associated S...Background:Second primary malignancies(SPMs)account for over 30%of total deaths in head and neck cancer(HNC)patients.The increasing use of radiotherapy raises concerns about the elevated risk of radiation-associated SPMs.This study aimed to investigate the age-stratified association between radiotherapy and SPM risk in survivors of non-metastatic primary HNC.Methods:Using data from the Surveillance,Epidemiology,and End Results program(2004-2015),incidence rate ratios(IRRs)and standardized incidence ratios(SIRs)were evaluated for solid and hematologic SPMs associated with radiotherapy within different age groups.Follow-up for hematologic and solid SPMs began 2 and 5 years,respectively,after the diagnosis of first primary HNC.The IRRs for SPMs were compared between radiotherapy-exposed and unexposed groups using multivariable modified Poisson regression.The SIRs were computed as the ratio of observed cancers in the cohort to expected cases derived from sex-,age-,and calendar year-matched general population incidence rates.Results:The study included 75,2092-year survivors,with 73.2%being male and a median age of 60 years.Of these,58,063 had survived 5 years or more.Radiotherapy was associated with an increased risk of solid SPMs[IRR=1.16,95%confidence interval(CI)1.08-1.24;P<0.001].The associations varied significantly among young(aged 15-39 years),middle-aged(aged 40-64 years),and elderly(aged 65-89 years)patients.Specifically,radiotherapy was associated with an increased risk of solid SPMs in middle-aged patients(IRR=1.21,95%CI 1.11-1.32;P<0.001),and a decreased risk of hematologic SPMs in elderly patients(IRR=0.77,95%CI 0.60-0.99;P=0.045).Compared with the general population,young patients had an elevated risk of radiotherapy-associated second primary non-Hodgkin lymphoma(SIR=4.01,95%CI 1.47-8.74).Middle-aged patients showed the highest SIR for SPMs in the bones/joints(SIR=7.72,95%CI 4.32-12.73),while elderly patients had the highest SIR for second primary esophageal malignancies(SIR=3.87,95%CI 2.91-5.05).Males were more likely to develop solid SPMs compared to females.Conclusions:This study reveals an age-stratified association between radiotherapy and the risk of SPMs in HNC patients.These findings highlight the importance of considering patient age when making treatment decisions for HNC and suggest that long-term surveillance is necessary for high-risk groups.展开更多
To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1...To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52274315 and 52374320)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-011A1 and FRF-DF22-16)。
文摘During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.
基金Supported by Major Project of School-level Teaching Reform and Research of Guangxi University of Chinese Medicine(2022A006)。
文摘In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.
基金supported by the National Natural Science Foundation of China(82101069)the Beijing Natural Science Foundation(7242279),the Beijing Nova Program(20230484283)+2 种基金the Beijing Municipal Science&Technology Commission(Z221100007422130)the Open Project of State Key Laboratory of Trauma and Chemical Poisoning(SKLO202401)the Logistics Independent Research Project of PLA(C24LBJ032).
文摘Background:Second primary malignancies(SPMs)account for over 30%of total deaths in head and neck cancer(HNC)patients.The increasing use of radiotherapy raises concerns about the elevated risk of radiation-associated SPMs.This study aimed to investigate the age-stratified association between radiotherapy and SPM risk in survivors of non-metastatic primary HNC.Methods:Using data from the Surveillance,Epidemiology,and End Results program(2004-2015),incidence rate ratios(IRRs)and standardized incidence ratios(SIRs)were evaluated for solid and hematologic SPMs associated with radiotherapy within different age groups.Follow-up for hematologic and solid SPMs began 2 and 5 years,respectively,after the diagnosis of first primary HNC.The IRRs for SPMs were compared between radiotherapy-exposed and unexposed groups using multivariable modified Poisson regression.The SIRs were computed as the ratio of observed cancers in the cohort to expected cases derived from sex-,age-,and calendar year-matched general population incidence rates.Results:The study included 75,2092-year survivors,with 73.2%being male and a median age of 60 years.Of these,58,063 had survived 5 years or more.Radiotherapy was associated with an increased risk of solid SPMs[IRR=1.16,95%confidence interval(CI)1.08-1.24;P<0.001].The associations varied significantly among young(aged 15-39 years),middle-aged(aged 40-64 years),and elderly(aged 65-89 years)patients.Specifically,radiotherapy was associated with an increased risk of solid SPMs in middle-aged patients(IRR=1.21,95%CI 1.11-1.32;P<0.001),and a decreased risk of hematologic SPMs in elderly patients(IRR=0.77,95%CI 0.60-0.99;P=0.045).Compared with the general population,young patients had an elevated risk of radiotherapy-associated second primary non-Hodgkin lymphoma(SIR=4.01,95%CI 1.47-8.74).Middle-aged patients showed the highest SIR for SPMs in the bones/joints(SIR=7.72,95%CI 4.32-12.73),while elderly patients had the highest SIR for second primary esophageal malignancies(SIR=3.87,95%CI 2.91-5.05).Males were more likely to develop solid SPMs compared to females.Conclusions:This study reveals an age-stratified association between radiotherapy and the risk of SPMs in HNC patients.These findings highlight the importance of considering patient age when making treatment decisions for HNC and suggest that long-term surveillance is necessary for high-risk groups.
基金supported by the National Natural Science Foundation of China(Grant Nos.52274339,52174321,52074186,and 52104337)Natural Science Foundation of Jiangsu Province(Grant No.BK20231317)China Baowu Low-Carbon Metallurgy Innovation Fund(Grant No.BWLCF202108).
文摘To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.
