This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on ...This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on the mechanical and damping properties of Mg-Ga sheet.The addition of Zn reduces the solid solubility of Ga inα-Mg,facilitating dynamic precipitation,grain refinement,and weakening of the basal texture of the sheet,ultimately enhancing strength and damping performance.The yield strength of the sheet initially increases and then decreases with increasing Zn content.The Mg-5Ga-0.6 Zn alloy demonstrates the best overall mechanical properties,with a yield strength,tensile strength,and elongation of 221 MPa,304 MPa,and 28.6%,respectively,primarily attributed to fine-grained strengthening.Damping performance at low strain amplitudes also follows a similar trend with increasing Zn content,with Mg-5Ga-0.6 Zn showing the highest damping values.The study suggests that the decrease in damping performance due to Zn can be linked to the reduced solid solubility of Ga inα-Mg.Specifically,at a strain amplitude of 1×10^(-3),the damping values Q-1 of Mg-5Ga,Mg-5Ga-0.6 Zn,and Mg-5Ga-1.2 Zn alloy sheets are 0.0167,0.0152,and 0.0174,respectively.These findings have implications for the development of bio-implantable magnesium alloys with high damping properties.展开更多
The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microsc...The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microscopy. The average dimension of primary austenite grains in hardfacing layer was measured by image analyzer. The primary austenite grain growth activation energy and index were calculated according to Sellars＇s mode and Beck formula, respectively. Moreover, the effect of rare earth oxide on the growth dynamics of primary aus- tenite grain was analyzed, and then discussed with the misfit theory. The experimental results showed that, by adding rare earth oxide, the av- erage dimension of primary austenite grains in hardfacing layer of medium-high carbon steel decreased, and it was the smallest when the ad- dition of rare earth oxide was 5.17 wt.%. Meanwhile, at this rare earth oxide addition, the primary austenite grain growth activating energy in hardfacing layer was the largest, while its index was the smallest. The calculated results indicated that the primary austenite grain could be refined because LaAlO3 as heterogeneous nuclei of γ-Fe was the most effective.展开更多
The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, th...The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.展开更多
Ester production in medium-high temperature Daqu(MHT-Daqu)significantly influences the flavor profile of strong-flavor Baijiu,but the details remain unclear.This study aimed to comprehensively profile the global map o...Ester production in medium-high temperature Daqu(MHT-Daqu)significantly influences the flavor profile of strong-flavor Baijiu,but the details remain unclear.This study aimed to comprehensively profile the global map of ester-producing metabolism and the involved key genes using multi-omics approaches.Metatranscriptome and metaproteome found that the global map of ester-producing metabolism mainly included carbohydrates,amino acids,organic acids.Integrated targeted metabolomics showed that the synthesis metabolism of alginate,glucose and arabinitol dominated by EC 2.4.1.64 and EC 3.2.1.86 was the main carbohydrate metabolism pathway,which was a prerequisite for ester production.The synthesis metabolism of glutamine,lysine,leucine,and glutamate dominated by EC 2.6.1.16,EC 3.4.19.13,and EC 1.5.1.7 was the main amino acid metabolism pathway,but its effect on ester production was not significant.The pyruvate metabolism transformation pathway,dominated by EC 2.2.1.6(acetolactate synthase,ALS)and EC 6.4.1.1,was one of the major organic acid metabolic pathways,which promoted ester production.Gene cloning and expression analyses found that,the expression patterns of the three genes cloned from the MHT-Daqu cDNA library in situ,JqALS1 encoding ALS,JqAAT1 encoding alcohol acetyltransferase,and JqADH1 encoding alcohol dehydrogenase,were overall consistent with the ester profiles over the whole production,proving their key role.Among them,the expression of JqAAT1 was significantly positively correlated with the environmental starch,amino acid nitrogen,and reducing sugar,while the expression of JqALS1 was mainly stimulated by the environmental temperature.These results facilitate the understanding of ester production in MHT-Daqu and the improvement of Baijiu flavor.展开更多
In this study,the physicochemical characteristics and bacterial community structure of Yunmen medium-high temperature Daqu were investigated.At the same time,the bacterial community structures of medium-high temperatu...In this study,the physicochemical characteristics and bacterial community structure of Yunmen medium-high temperature Daqu were investigated.At the same time,the bacterial community structures of medium-high temperature Daqu from Yunmen and Yingtan were compared and analyzed.The results showed that Yunmen medium-high temperature Daqu was rich in culturable bacteria,and the highest number of Bacillus amyloliquefaciens(33.33%).The moisture content(8.28%±0.62%)of Yunmen medium-high temperature Daqu was low,but its acidity(9.26±2.08 mmoL/10 g)and starch content(66.20%±2.80%)were high,which were related to the relative abundance of Latilactobacillus,Companilactobacillus,Weissella,and Bacillus.Compared with Yingtan medium-high temperature Daqu,the significantly lower Shannon index and Simpson index(P<0.05);the weaker correlation between bacterial networks,especially positive correlation;and the lower relative abundance of core bacterial communities of Yunmen medium-high temperature Daqu.Overall,this study evaluated the quality of Yunmen medium-high temperature Daqu and revealed the bacterial community structure of medium-high temperature Daqu from two different regions.The results could guide the future exploration of fermentation mechanisms in medium-high temperature Daqu.展开更多
Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the ...Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the temperature and humidity change rate during the warming period to affect the structure and function of the Daqu microbiota.The results of the study showed that Daqu fermentation occurs in two stages:the temperature increase period(P1),and the combined high temperature and temperature cooling period(P2),with rapid changes in the microbial community structure at the P1 stage,but not significant at the P2 stage.The microbial community structure of Daqu in P1 stage was significantly correlated with environmental factors.Under different rates of temperature and humidity changes,the succession of microbial communities,the breadth of microbial ecological niches along environmental gradients,and the patterns of community assembly differ,resulting in differences in the microbial community structure in Daqu.The slower rate of temperature and humidity change endows Daqu microorganisms with higher species diversity,and makes the abundance of enzymes related to carbohydrate decomposition and volatile metabolite formation in Daqu microorganisms higher,further resulting in a higher content of flavor substances(e.g.Ester content:20 mg/kg at slow rate,4 mg/kg at fast rate).These findings will facilitate more accurate regulation of Daqu production by controlling the rate of temperature and humidity changes during the temperature increase period.展开更多
基金supported by National Natural Science Foundation of China(Grant No.51871093)the Scientific Research Program for Introducing Talents of Guizhou University(No.2023(06))the Basic Research Program of Guizhou University(No.2023(02)).
文摘This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on the mechanical and damping properties of Mg-Ga sheet.The addition of Zn reduces the solid solubility of Ga inα-Mg,facilitating dynamic precipitation,grain refinement,and weakening of the basal texture of the sheet,ultimately enhancing strength and damping performance.The yield strength of the sheet initially increases and then decreases with increasing Zn content.The Mg-5Ga-0.6 Zn alloy demonstrates the best overall mechanical properties,with a yield strength,tensile strength,and elongation of 221 MPa,304 MPa,and 28.6%,respectively,primarily attributed to fine-grained strengthening.Damping performance at low strain amplitudes also follows a similar trend with increasing Zn content,with Mg-5Ga-0.6 Zn showing the highest damping values.The study suggests that the decrease in damping performance due to Zn can be linked to the reduced solid solubility of Ga inα-Mg.Specifically,at a strain amplitude of 1×10^(-3),the damping values Q-1 of Mg-5Ga,Mg-5Ga-0.6 Zn,and Mg-5Ga-1.2 Zn alloy sheets are 0.0167,0.0152,and 0.0174,respectively.These findings have implications for the development of bio-implantable magnesium alloys with high damping properties.
基金Program supported by National Nature Science Foundation of China(51271163)Key Project of Science and Technology of Hebei Province(09215106D)
文摘The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microscopy. The average dimension of primary austenite grains in hardfacing layer was measured by image analyzer. The primary austenite grain growth activation energy and index were calculated according to Sellars＇s mode and Beck formula, respectively. Moreover, the effect of rare earth oxide on the growth dynamics of primary aus- tenite grain was analyzed, and then discussed with the misfit theory. The experimental results showed that, by adding rare earth oxide, the av- erage dimension of primary austenite grains in hardfacing layer of medium-high carbon steel decreased, and it was the smallest when the ad- dition of rare earth oxide was 5.17 wt.%. Meanwhile, at this rare earth oxide addition, the primary austenite grain growth activating energy in hardfacing layer was the largest, while its index was the smallest. The calculated results indicated that the primary austenite grain could be refined because LaAlO3 as heterogeneous nuclei of γ-Fe was the most effective.
文摘The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.
基金supported by National Key R&D Program of China(No.2018YFE0127400)Open-foundation project Liquor Making Biological Technology and Application of Key Laboratory of Sichuan Province(No.NJ2023-01★).
文摘Ester production in medium-high temperature Daqu(MHT-Daqu)significantly influences the flavor profile of strong-flavor Baijiu,but the details remain unclear.This study aimed to comprehensively profile the global map of ester-producing metabolism and the involved key genes using multi-omics approaches.Metatranscriptome and metaproteome found that the global map of ester-producing metabolism mainly included carbohydrates,amino acids,organic acids.Integrated targeted metabolomics showed that the synthesis metabolism of alginate,glucose and arabinitol dominated by EC 2.4.1.64 and EC 3.2.1.86 was the main carbohydrate metabolism pathway,which was a prerequisite for ester production.The synthesis metabolism of glutamine,lysine,leucine,and glutamate dominated by EC 2.6.1.16,EC 3.4.19.13,and EC 1.5.1.7 was the main amino acid metabolism pathway,but its effect on ester production was not significant.The pyruvate metabolism transformation pathway,dominated by EC 2.2.1.6(acetolactate synthase,ALS)and EC 6.4.1.1,was one of the major organic acid metabolic pathways,which promoted ester production.Gene cloning and expression analyses found that,the expression patterns of the three genes cloned from the MHT-Daqu cDNA library in situ,JqALS1 encoding ALS,JqAAT1 encoding alcohol acetyltransferase,and JqADH1 encoding alcohol dehydrogenase,were overall consistent with the ester profiles over the whole production,proving their key role.Among them,the expression of JqAAT1 was significantly positively correlated with the environmental starch,amino acid nitrogen,and reducing sugar,while the expression of JqALS1 was mainly stimulated by the environmental temperature.These results facilitate the understanding of ester production in MHT-Daqu and the improvement of Baijiu flavor.
基金supported by the Hubei Provincial Natural Science Foundation Joint Fund for Innovation and Development Project(2023AFD049)Hubei University of Arts and Science Cultivation Fund for Teachers’Scientific Research Ability:Technological Innovation Team(2020kypytd009).
文摘In this study,the physicochemical characteristics and bacterial community structure of Yunmen medium-high temperature Daqu were investigated.At the same time,the bacterial community structures of medium-high temperature Daqu from Yunmen and Yingtan were compared and analyzed.The results showed that Yunmen medium-high temperature Daqu was rich in culturable bacteria,and the highest number of Bacillus amyloliquefaciens(33.33%).The moisture content(8.28%±0.62%)of Yunmen medium-high temperature Daqu was low,but its acidity(9.26±2.08 mmoL/10 g)and starch content(66.20%±2.80%)were high,which were related to the relative abundance of Latilactobacillus,Companilactobacillus,Weissella,and Bacillus.Compared with Yingtan medium-high temperature Daqu,the significantly lower Shannon index and Simpson index(P<0.05);the weaker correlation between bacterial networks,especially positive correlation;and the lower relative abundance of core bacterial communities of Yunmen medium-high temperature Daqu.Overall,this study evaluated the quality of Yunmen medium-high temperature Daqu and revealed the bacterial community structure of medium-high temperature Daqu from two different regions.The results could guide the future exploration of fermentation mechanisms in medium-high temperature Daqu.
基金supported by the Innovation Fund of Postgraduate,Luzhou Laojiao Co.,Ltd.(No.LJCX2023-4)the Project of the Science and Technology Department of Sichuan Province(No.2024ZHCG0094).
文摘Medium-high temperature Daqu is primarily controlled during the production process by regulating environmental temperature and humidity to manage fermentation.In this study,we analyzed the mechanism of regulating the temperature and humidity change rate during the warming period to affect the structure and function of the Daqu microbiota.The results of the study showed that Daqu fermentation occurs in two stages:the temperature increase period(P1),and the combined high temperature and temperature cooling period(P2),with rapid changes in the microbial community structure at the P1 stage,but not significant at the P2 stage.The microbial community structure of Daqu in P1 stage was significantly correlated with environmental factors.Under different rates of temperature and humidity changes,the succession of microbial communities,the breadth of microbial ecological niches along environmental gradients,and the patterns of community assembly differ,resulting in differences in the microbial community structure in Daqu.The slower rate of temperature and humidity change endows Daqu microorganisms with higher species diversity,and makes the abundance of enzymes related to carbohydrate decomposition and volatile metabolite formation in Daqu microorganisms higher,further resulting in a higher content of flavor substances(e.g.Ester content:20 mg/kg at slow rate,4 mg/kg at fast rate).These findings will facilitate more accurate regulation of Daqu production by controlling the rate of temperature and humidity changes during the temperature increase period.
