The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, auto- mobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and g...Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, auto- mobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and good corrosion resistance. However, during forging processes, underfilling, folding, broken streamline, crack, coarse grain, and other macro- or microdefects are easily generated because of the deformation characteristics of aluminum alloys, including narrow forgeable temperature region, fast heat dissipation to dies, strong adhesion, high strain rate sensitivity, and large flow resistance. Thus, it is seriously restricted for the forged part to obtain precision shape and enhanced property. In this paper, progresses in precision forging technologies of aluminum alloy parts were reviewed. Several advanced precision forging technologies have been developed, including closed die forging, isothermal die forging, local loading forging, metal flow forging with relief cavity, auxiliary force or vibration loading, casting-forging hybrid forming, and stamping-forging hybrid forming. High-precision alumi- num alloy parts can be realized by controlling the forging processes and parameters or combining precision forging technologies with other forming technologies. The development of these technologies is beneficial to promote the application of aluminum alloys in manufacturing of lightweight parts.展开更多
Isothermal forging(IF)is an effective method for forming difficult-to-deform materials like P/M superalloys.Understanding the isothermal compression microstructural evolution mechanism of a novel P/M s-peralloy provid...Isothermal forging(IF)is an effective method for forming difficult-to-deform materials like P/M superalloys.Understanding the isothermal compression microstructural evolution mechanism of a novel P/M s-peralloy provides the basis for its optimized IF planning.In this study,the isothermal compression tests of a novel fine-grained P/M nickel-based superalloy were carried out at 1000-1150℃with strain rates of 0.001-0.01 s^(−1).The results indicated that the alloy exhibits three distinct flow characteristics:continuous softening after reaching the peak stress,near-steady superplastic flow,and discontinuous hardening,corresponding to different strain rate sensitivity exponent(m)values.Varied microstructural evolution mechanisms,including grain boundary sliding(GBS),dynamic recrystallization(DRX),and grain growth,are dominated in different m-value domains.Meanwhile,different roles of primaryγ’play in microstruc-tural evolution were clarified.A moderate fraction of primaryγ’with 8.5%-14.2%can well coordinate the GBS and hinder excessive grain growth at a high m value domain(m>0.4).When 0.2<m<0.4,the role of the primaryγ’is changed to promote dislocation accumulation,accelerating the nucleation of DRXed grains.As the primaryγ’is dissolved at 1150℃,obvious grain growth was observed after compression.Work hardening effect by overgrown grains competed with DRX softening results in the discontinuous rising stress.展开更多
Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of a...Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.展开更多
This study aimed to investigate the metabolic profile of gestational diabetes mellitus(GDM)at both antepartum and postpartum periods.Seventy pregnant women were divided into three groups:the normal glucose-tolerant gr...This study aimed to investigate the metabolic profile of gestational diabetes mellitus(GDM)at both antepartum and postpartum periods.Seventy pregnant women were divided into three groups:the normal glucose-tolerant group(NGT,n=35),the abnormal glucose-tolerant groups without insulin therapy(A1GDM,n=24)or with insulin therapy(A2GDM,n=11).Metabolic profiles of the plasma were acquired by proton nuclear magnetic resonance(1H-NMR)spectroscopy and analyzed by multivariate statistical data analysis.The relationship between demographic parameters and the potential metabolite biomarkers was further explored.Group antepartum or postpartum showed similar metabolic trends.Compare with those of the NGT group,the levels of 2-hydroxybutyrate,lysine,acetate,glutamine,succinate,tyrosine,formate,and all three BCAAs(leucine,valine,isoleucine)in the A2GDM group were increased dramatically,and the levels of lysine,acetate,and formate in the A1GDM group were elevated significantly.The dramatically decreased levels of 3-methyl-2-oxovalerate and methanol were observed both in the A1GDM group and A2GDM group.Compare to the A1GDM group,the branched-chain amino acids(BCAAs)of leucine,valine,and isoleucine were increased dramatically in the A2GDM group.The levels of aromatic amino acids(AAAs),tyrosine and phenylalanine,were significantly increased in GDM women,consistent with the severity of GDM.Interference of amino acid metabolism and disturbance in energy metabolism occurred in women with different grades of GDM.Metabolic profiles could reflect the severity of GDM.Plasma BCAA concentrations showing strong positive correlations with weight and pre-delivery BMI.This study provides a new perspective to understand the pathogenesis and etiology of GDM,which may help the clinical management and treatment of GDM.展开更多
The aim of this paper is to review the state-of-the-art SFPs and their applications,and to provide a guide for researchers and engineers working in this field.Various SFPs are classified according to the combination w...The aim of this paper is to review the state-of-the-art SFPs and their applications,and to provide a guide for researchers and engineers working in this field.Various SFPs are classified according to the combination ways of stamping and forging operations.The process principle of each combination is reviewed,with its applications discussed.The state-of-the-art of SFPs suggests that future work in this field should focus on the development of high-strength die materials,better lubrication control methods,forming machines with intelligent control capacity and special functions,and some new SFPs for high strength or ultra-high strength materials.展开更多
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金The authors would like to thank the support from Shenzhen Knowledge Innovation Project （Grant No. 201605313001169） and the National Natural Science Foundation of China （Grant No. 51435007）.
文摘Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, auto- mobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and good corrosion resistance. However, during forging processes, underfilling, folding, broken streamline, crack, coarse grain, and other macro- or microdefects are easily generated because of the deformation characteristics of aluminum alloys, including narrow forgeable temperature region, fast heat dissipation to dies, strong adhesion, high strain rate sensitivity, and large flow resistance. Thus, it is seriously restricted for the forged part to obtain precision shape and enhanced property. In this paper, progresses in precision forging technologies of aluminum alloy parts were reviewed. Several advanced precision forging technologies have been developed, including closed die forging, isothermal die forging, local loading forging, metal flow forging with relief cavity, auxiliary force or vibration loading, casting-forging hybrid forming, and stamping-forging hybrid forming. High-precision alumi- num alloy parts can be realized by controlling the forging processes and parameters or combining precision forging technologies with other forming technologies. The development of these technologies is beneficial to promote the application of aluminum alloys in manufacturing of lightweight parts.
基金supported by the National Natural Science Foundation of China(Nos.52175319 and 52090043)the Fundamental Research Funds for the Central Universities(No.YCJJ202202003)the National Science and Technology Major Project(No.2017-Ⅵ-0009-0080).
文摘Isothermal forging(IF)is an effective method for forming difficult-to-deform materials like P/M superalloys.Understanding the isothermal compression microstructural evolution mechanism of a novel P/M s-peralloy provides the basis for its optimized IF planning.In this study,the isothermal compression tests of a novel fine-grained P/M nickel-based superalloy were carried out at 1000-1150℃with strain rates of 0.001-0.01 s^(−1).The results indicated that the alloy exhibits three distinct flow characteristics:continuous softening after reaching the peak stress,near-steady superplastic flow,and discontinuous hardening,corresponding to different strain rate sensitivity exponent(m)values.Varied microstructural evolution mechanisms,including grain boundary sliding(GBS),dynamic recrystallization(DRX),and grain growth,are dominated in different m-value domains.Meanwhile,different roles of primaryγ’play in microstruc-tural evolution were clarified.A moderate fraction of primaryγ’with 8.5%-14.2%can well coordinate the GBS and hinder excessive grain growth at a high m value domain(m>0.4).When 0.2<m<0.4,the role of the primaryγ’is changed to promote dislocation accumulation,accelerating the nucleation of DRXed grains.As the primaryγ’is dissolved at 1150℃,obvious grain growth was observed after compression.Work hardening effect by overgrown grains competed with DRX softening results in the discontinuous rising stress.
文摘Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.
文摘This study aimed to investigate the metabolic profile of gestational diabetes mellitus(GDM)at both antepartum and postpartum periods.Seventy pregnant women were divided into three groups:the normal glucose-tolerant group(NGT,n=35),the abnormal glucose-tolerant groups without insulin therapy(A1GDM,n=24)or with insulin therapy(A2GDM,n=11).Metabolic profiles of the plasma were acquired by proton nuclear magnetic resonance(1H-NMR)spectroscopy and analyzed by multivariate statistical data analysis.The relationship between demographic parameters and the potential metabolite biomarkers was further explored.Group antepartum or postpartum showed similar metabolic trends.Compare with those of the NGT group,the levels of 2-hydroxybutyrate,lysine,acetate,glutamine,succinate,tyrosine,formate,and all three BCAAs(leucine,valine,isoleucine)in the A2GDM group were increased dramatically,and the levels of lysine,acetate,and formate in the A1GDM group were elevated significantly.The dramatically decreased levels of 3-methyl-2-oxovalerate and methanol were observed both in the A1GDM group and A2GDM group.Compare to the A1GDM group,the branched-chain amino acids(BCAAs)of leucine,valine,and isoleucine were increased dramatically in the A2GDM group.The levels of aromatic amino acids(AAAs),tyrosine and phenylalanine,were significantly increased in GDM women,consistent with the severity of GDM.Interference of amino acid metabolism and disturbance in energy metabolism occurred in women with different grades of GDM.Metabolic profiles could reflect the severity of GDM.Plasma BCAA concentrations showing strong positive correlations with weight and pre-delivery BMI.This study provides a new perspective to understand the pathogenesis and etiology of GDM,which may help the clinical management and treatment of GDM.
基金Sponsored by the National Natural Science Foundation of China(Grant Nos.50705034,51175202,51435007 and 51675201)
文摘The aim of this paper is to review the state-of-the-art SFPs and their applications,and to provide a guide for researchers and engineers working in this field.Various SFPs are classified according to the combination ways of stamping and forging operations.The process principle of each combination is reviewed,with its applications discussed.The state-of-the-art of SFPs suggests that future work in this field should focus on the development of high-strength die materials,better lubrication control methods,forming machines with intelligent control capacity and special functions,and some new SFPs for high strength or ultra-high strength materials.
