Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
Dandelion-like TiO2 microspheres consisting of numerous rutile single-crystalline nanorods were synthesized for the first time by a hydrothermal method. Their crystal structure, morphology and electrochemical properti...Dandelion-like TiO2 microspheres consisting of numerous rutile single-crystalline nanorods were synthesized for the first time by a hydrothermal method. Their crystal structure, morphology and electrochemical properties were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and galvanostatic charge and discharge tests. The results show that the synthesized TiO2 microspheres exhibit good rate and cycle performances as anode materials of lithium ion batteries. It can be found that the dandelion-like structure provides a larger specific surface area and the single-crystalline nanorod provides a stable structure and fast pathways for electron and lithium ion transport, which contribute to the rate and cycle performances of the battery.展开更多
Keratinases can specifically degrade keratins,which widely exist in hair,horns,claws and human skin.There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reus...Keratinases can specifically degrade keratins,which widely exist in hair,horns,claws and human skin.There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reusing keratin products in agriculture,medical treatment and feed industries.Degradation of keratin waste by keratinase is more environmentally friendly and more sustainable compared with chemical and physical methods.However,the wildtype keratinase-producing strains usually cannot meet the requirements of industrial production,and some are pathogenic,limiting their development and utilization.The main purpose of this study is to improve the catalytic performance of keratinase via directed evolution technology for the degradation of feathers.We first constructed a mutant library through error-prone PCR and screened variants with enhanced enzyme activity.The keratinase activity was further improved through fermentation conditions optimization and fed-batch strategies in a 7-L bioreactor.As a result,nine mutants with enhanced activity were identified and the highest enzyme activity was improved from 1150 to 8448 U/mL finally.The mutant achieved efficient biodegradation of feathers,increasing the degradation rate from 49 to 88%.Moreover,a large number of amino acids and soluble peptides were obtained as degradation products,which were excellent protein resources to feed.Therefore,the study provided a keratinase mutant with application potential in the management of feather waste and preparation of protein feed additive.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
基金was financially supported by the Joint Project of the National Natural Science Foundation of Chinathe Natural Science Foundation of Guangdong Province,China(No.U1134002),the Natural Science Foundation of Guangdong Province,China(No.10351063101000001)the Key Project of Science and Technology in Guangdong Province,China(No.2010A090602003)
文摘Dandelion-like TiO2 microspheres consisting of numerous rutile single-crystalline nanorods were synthesized for the first time by a hydrothermal method. Their crystal structure, morphology and electrochemical properties were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and galvanostatic charge and discharge tests. The results show that the synthesized TiO2 microspheres exhibit good rate and cycle performances as anode materials of lithium ion batteries. It can be found that the dandelion-like structure provides a larger specific surface area and the single-crystalline nanorod provides a stable structure and fast pathways for electron and lithium ion transport, which contribute to the rate and cycle performances of the battery.
基金financially supported by the National Key Research and Development Program of China(No.2021YFC2100900)the National Natural Science Foundation of China(No.21978116)the Ningxia Hui Autonomous Region Key Research&Development Plan(No.2019BCH01002).
文摘Keratinases can specifically degrade keratins,which widely exist in hair,horns,claws and human skin.There is a great interest in developing keratinase to manage keratin waste generated by the poultry industry and reusing keratin products in agriculture,medical treatment and feed industries.Degradation of keratin waste by keratinase is more environmentally friendly and more sustainable compared with chemical and physical methods.However,the wildtype keratinase-producing strains usually cannot meet the requirements of industrial production,and some are pathogenic,limiting their development and utilization.The main purpose of this study is to improve the catalytic performance of keratinase via directed evolution technology for the degradation of feathers.We first constructed a mutant library through error-prone PCR and screened variants with enhanced enzyme activity.The keratinase activity was further improved through fermentation conditions optimization and fed-batch strategies in a 7-L bioreactor.As a result,nine mutants with enhanced activity were identified and the highest enzyme activity was improved from 1150 to 8448 U/mL finally.The mutant achieved efficient biodegradation of feathers,increasing the degradation rate from 49 to 88%.Moreover,a large number of amino acids and soluble peptides were obtained as degradation products,which were excellent protein resources to feed.Therefore,the study provided a keratinase mutant with application potential in the management of feather waste and preparation of protein feed additive.
