Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selectiv...Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.展开更多
In order to learn the enzymatic characteristics of Huai yam powder with medium-temperatureα-amylase, effects of substrate concentration,enzyme concentration, pH and temperature wereinvestigated. The Michealis-Menten ...In order to learn the enzymatic characteristics of Huai yam powder with medium-temperatureα-amylase, effects of substrate concentration,enzyme concentration, pH and temperature wereinvestigated. The Michealis-Menten equationwas used to fit the kinetics of the hydrolysis reaction. Experimental results indicate that maximum rate (Vm) is 3.1588 mg/mL·min under the condition of 70°C, pH 7.0 and 0.0200 mg/mL of enzyme concentration. The Michealis constant (Km) is 6.6641 mg/mL. The kinetic model, including the factors such as substrate concentration, enzyme concentration and temperature, was established for the hydrolysis reaction under the temperature range from 40°C - 70°C.展开更多
Background A reliable and repeatable post-processing technology of improving the performance of 1.3 GHz superconducting radio frequency(SRF)cavities is one of the critical technologies for the ILC and XFEL and ERL pro...Background A reliable and repeatable post-processing technology of improving the performance of 1.3 GHz superconducting radio frequency(SRF)cavities is one of the critical technologies for the ILC and XFEL and ERL projects.Methods Three 1.3 GHz single-cell cavities were fabricated and received a baking in temperature 330℃,while the interior of the cavity stayed in ultra-high vacuum(UHV).The cavities were also vertical-tested after electropolishing(EP)with 120℃48-h baking and with nitrogen doping separately for a comparison.Results The Q_(0) of 1.3 GHz single cavity after medium-temperature baking can be 2-3×10^(10) in the accelerating gradient range of 2-35 MV/m in the 2 K vertical test in IHEP.Meanwhile,the outer surface oxidation of niobium cavity caused by baking will decrease the performance of the SRF cavity.Conclusions Medium-temperature(250-400℃)baking on the 1.3 GHz single-cell cavity will improve its Q_(0) in 2 K vertical test compared with EP followed by 120℃48-h baking baseline and reach a similar level of nitrogen doping,and the quench field will lower to a typical range of 20-30 MV/m.Meanwhile,the cavity performance is sensitive to the baking time and temperature,which indicates that a tremendous improvement can be made on the current treatment.展开更多
Medium-temperature Daqu acts as a fermentation starter for strong-flavor Baijiu.However,there is limited research available in terms of its quality attributes and formation mechanisms.In this study,the distinct char-a...Medium-temperature Daqu acts as a fermentation starter for strong-flavor Baijiu.However,there is limited research available in terms of its quality attributes and formation mechanisms.In this study,the distinct char-acteristics of different quality medium-temperature Daqu were examined using the novel Qu-omics techniques.Multivariate statistical analyses indicated that the high-quality strong-flavor medium-temperature Daqu had increased acidity and enzyme activity,with the most significant variation observed in acidic protease activity.We revealed for the first time that mucorpepsin derived from Rhizomucor pusillus was the primary source of the acidic protease in high-quality Daqu using in-depth analysis.Volatile composition analysis revealed a positive correlation between nitrogenous and acidic substances with the predominant bacterial genera of Daqu,while a negative correlation was observed with the dominant fungal genera.The principal source of acidic compounds in Daqu was revealed to be lactic acid bacteria,and the inter-group differences in aromatic compounds were extremely significant(p<0.001).The levels of phenylmethanol,phenylethanol,benzaldehyde,phenol,and 4-ethylguaiacol were significantly higher in high-quality Daqu compared to abnormal Daqu,while notably lower levels of phenylacetaldehyde,(±)-1-phenyl-2-propanol,phenylacetone,and other off-flavor substances were detected in high-quality Daqu than in abnormal Daqu(p<0.05).展开更多
Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearl...Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearly detected in the outlet gas before 20 h breakthrough time.The effects of the main operational conditions and the particle size of Z20SC sorbent on its desulfurization performances sorbent were investigated in a fixed-bed reactor and the desulfurization kinetics of Z20SC sorbent removing H2 S from hot coal gas was calculated based on experimental data.Results showed that the conversion of Z20SC sorbent desulfurization reaction increased with the decrease of the particle size of the sorbent and the increases of gas volumetric flow rate,reaction temperature and H 2 S content in inlet gas.Z20SC sorbent obtained from hydrothermal synthesis by high-pressure impregnation possessed much larger surface area and pore volume than semi-coke support,and they were significantly reduced after the desulfurization reaction.The equivalent grain model was reasonably used to analyze experimental data,in which k s=4.382×10-3 exp（-8.270×103/RgT） and Dep=1.262×10-4exp（1.522×104/RgT）.It suggests that the desulfurization reaction of the Z20SC sorbent is mainly controlled by the chemical reaction in the initial stage and later by the diffusion through the reacted sorbent layer.展开更多
Using the previous batch of fermented product to initiate fermentation(i.e.,community-level bioaugmentation)is a common production technique for fermented foods.As the saccharification,fermentation,and aroma-producing...Using the previous batch of fermented product to initiate fermentation(i.e.,community-level bioaugmentation)is a common production technique for fermented foods.As the saccharification,fermentation,and aroma-producing agent in strong-flavor Baijiu brewing,medium-temperature Daqu is usually produced by spontaneous fermentation without any exogenous microorganisms inoculated.Here,we selected Daqu from day 12(FerDq)and day 30(MatDq)of the previous batch as starters to perform bioaugmentation.Bioaugmentation enhanced total acidity,enzymatic activities,and volatiles,particularly alcohols and pyrazines.Metagenomics revealed that bioaugmentation with 5%or 10%(w/w)FerDq enhanced the relative abundances of Staphylococcus and Bacillus,whereas bioaugmentation with 5%or 10%(w/w)MatDq enriched Bacillus,Aspergillus,Talaromyces,and Rasamsonia.The increase in liquefying activity in MatDq groups was due to the increase in alpha-amylase and glycogen phosphorylase abundances,mainly caused by the enrichment of Aspergillus,Talaromyces,and Bacillus.Bioaugmentation with FerDq significantly increased the gene abundance of carboxyesterase and esterifying activity of Daqu via Staphylococcus and Bacillus.The enriched Bacillus,Staphylococcus,and Paenibacillus in FerDq groups facilitated the production of pyrazines.The metabolic pathway of phenylethyl alcohol biosynthesis varied among different groups.In the control group,it was mainly produced by aryl-alcohol dehydrogenase,which originated from Lactobacillales,while in the bioaugmented groups,it was mainly produced through alcohol dehydrogenase and formaldehyde dehydrogenase,which were derived from Rhizopus and Bacillus in the FerDq groups and from Rasamsonia,Talaromyces,Rhizopus,and Bacillus in the MatDq groups.This study revealed the feasibility of producing enzymatic activity-and aroma-enhanced Daqu through community-level bioaugmentation.展开更多
基金the Science and Technology Key Project of Anhui Province,China(No.2022e03020004).
文摘Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.
文摘In order to learn the enzymatic characteristics of Huai yam powder with medium-temperatureα-amylase, effects of substrate concentration,enzyme concentration, pH and temperature wereinvestigated. The Michealis-Menten equationwas used to fit the kinetics of the hydrolysis reaction. Experimental results indicate that maximum rate (Vm) is 3.1588 mg/mL·min under the condition of 70°C, pH 7.0 and 0.0200 mg/mL of enzyme concentration. The Michealis constant (Km) is 6.6641 mg/mL. The kinetic model, including the factors such as substrate concentration, enzyme concentration and temperature, was established for the hydrolysis reaction under the temperature range from 40°C - 70°C.
基金supported by the Platform of Advanced Photon Source Technology R&D
文摘Background A reliable and repeatable post-processing technology of improving the performance of 1.3 GHz superconducting radio frequency(SRF)cavities is one of the critical technologies for the ILC and XFEL and ERL projects.Methods Three 1.3 GHz single-cell cavities were fabricated and received a baking in temperature 330℃,while the interior of the cavity stayed in ultra-high vacuum(UHV).The cavities were also vertical-tested after electropolishing(EP)with 120℃48-h baking and with nitrogen doping separately for a comparison.Results The Q_(0) of 1.3 GHz single cavity after medium-temperature baking can be 2-3×10^(10) in the accelerating gradient range of 2-35 MV/m in the 2 K vertical test in IHEP.Meanwhile,the outer surface oxidation of niobium cavity caused by baking will decrease the performance of the SRF cavity.Conclusions Medium-temperature(250-400℃)baking on the 1.3 GHz single-cell cavity will improve its Q_(0) in 2 K vertical test compared with EP followed by 120℃48-h baking baseline and reach a similar level of nitrogen doping,and the quench field will lower to a typical range of 20-30 MV/m.Meanwhile,the cavity performance is sensitive to the baking time and temperature,which indicates that a tremendous improvement can be made on the current treatment.
基金supported by the National Natural Science Foundation of China[grant number 32172176]the National Key R&D Program of China[grant number 2022YFD2101201].
文摘Medium-temperature Daqu acts as a fermentation starter for strong-flavor Baijiu.However,there is limited research available in terms of its quality attributes and formation mechanisms.In this study,the distinct char-acteristics of different quality medium-temperature Daqu were examined using the novel Qu-omics techniques.Multivariate statistical analyses indicated that the high-quality strong-flavor medium-temperature Daqu had increased acidity and enzyme activity,with the most significant variation observed in acidic protease activity.We revealed for the first time that mucorpepsin derived from Rhizomucor pusillus was the primary source of the acidic protease in high-quality Daqu using in-depth analysis.Volatile composition analysis revealed a positive correlation between nitrogenous and acidic substances with the predominant bacterial genera of Daqu,while a negative correlation was observed with the dominant fungal genera.The principal source of acidic compounds in Daqu was revealed to be lactic acid bacteria,and the inter-group differences in aromatic compounds were extremely significant(p<0.001).The levels of phenylmethanol,phenylethanol,benzaldehyde,phenol,and 4-ethylguaiacol were significantly higher in high-quality Daqu compared to abnormal Daqu,while notably lower levels of phenylacetaldehyde,(±)-1-phenyl-2-propanol,phenylacetone,and other off-flavor substances were detected in high-quality Daqu than in abnormal Daqu(p<0.05).
基金supported by the National Basic Research Program of China (2012CB723105)the National Natural Science Foundation of China(20976117)+1 种基金Shanxi Province Natural Science Foundation (2010011014-3)Shanxi Province Basic Conditions Platform for Science and Technology Project(2010091015)
文摘Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearly detected in the outlet gas before 20 h breakthrough time.The effects of the main operational conditions and the particle size of Z20SC sorbent on its desulfurization performances sorbent were investigated in a fixed-bed reactor and the desulfurization kinetics of Z20SC sorbent removing H2 S from hot coal gas was calculated based on experimental data.Results showed that the conversion of Z20SC sorbent desulfurization reaction increased with the decrease of the particle size of the sorbent and the increases of gas volumetric flow rate,reaction temperature and H 2 S content in inlet gas.Z20SC sorbent obtained from hydrothermal synthesis by high-pressure impregnation possessed much larger surface area and pore volume than semi-coke support,and they were significantly reduced after the desulfurization reaction.The equivalent grain model was reasonably used to analyze experimental data,in which k s=4.382×10-3 exp（-8.270×103/RgT） and Dep=1.262×10-4exp（1.522×104/RgT）.It suggests that the desulfurization reaction of the Z20SC sorbent is mainly controlled by the chemical reaction in the initial stage and later by the diffusion through the reacted sorbent layer.
基金supported by the National Key Research and Development Plan of China[grant number 2018YFE0127400]National Natural Science Foundation of China[grant number 31901117]the project of the Science and Technology Department in Sichuan province[grant number 2021ZYD0102].
文摘Using the previous batch of fermented product to initiate fermentation(i.e.,community-level bioaugmentation)is a common production technique for fermented foods.As the saccharification,fermentation,and aroma-producing agent in strong-flavor Baijiu brewing,medium-temperature Daqu is usually produced by spontaneous fermentation without any exogenous microorganisms inoculated.Here,we selected Daqu from day 12(FerDq)and day 30(MatDq)of the previous batch as starters to perform bioaugmentation.Bioaugmentation enhanced total acidity,enzymatic activities,and volatiles,particularly alcohols and pyrazines.Metagenomics revealed that bioaugmentation with 5%or 10%(w/w)FerDq enhanced the relative abundances of Staphylococcus and Bacillus,whereas bioaugmentation with 5%or 10%(w/w)MatDq enriched Bacillus,Aspergillus,Talaromyces,and Rasamsonia.The increase in liquefying activity in MatDq groups was due to the increase in alpha-amylase and glycogen phosphorylase abundances,mainly caused by the enrichment of Aspergillus,Talaromyces,and Bacillus.Bioaugmentation with FerDq significantly increased the gene abundance of carboxyesterase and esterifying activity of Daqu via Staphylococcus and Bacillus.The enriched Bacillus,Staphylococcus,and Paenibacillus in FerDq groups facilitated the production of pyrazines.The metabolic pathway of phenylethyl alcohol biosynthesis varied among different groups.In the control group,it was mainly produced by aryl-alcohol dehydrogenase,which originated from Lactobacillales,while in the bioaugmented groups,it was mainly produced through alcohol dehydrogenase and formaldehyde dehydrogenase,which were derived from Rhizopus and Bacillus in the FerDq groups and from Rasamsonia,Talaromyces,Rhizopus,and Bacillus in the MatDq groups.This study revealed the feasibility of producing enzymatic activity-and aroma-enhanced Daqu through community-level bioaugmentation.
