By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measur...By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measured near the perimeter of the islands.This feature is very different from the single zero-energy peak observed on some other small Bi islands.The edge states spread towards the inner side of the islands over a width of 2-3 nm.The two edge-state peaks at positive and negative energies move to higher values with the increase of the magnetic field,and they disappear near the transition temperature of FeTe_(0.55)Se_(0.45).Meanwhile,enhanced superconducting gaps are observed in the central regions of these Bi islands,which may be induced by the enhanced pair potential of the topological surface state.Our observations provide a valuable message for the edge state and the proximity-induced superconductivity on specific Bi islands grown on FeTe_(0.55)Se_(0.45)substrate.展开更多
短期预测在智能电网建设中扮演着重要角色,深刻影响电网发输变配用各个环节的智能化改造。短期预测一般基于系统实测数据,而传感器故障,数据传输错误等原因会导致数据质量下降,严重影响短期预测的精确性。为建立数据质量受损情况下的精...短期预测在智能电网建设中扮演着重要角色,深刻影响电网发输变配用各个环节的智能化改造。短期预测一般基于系统实测数据,而传感器故障,数据传输错误等原因会导致数据质量下降,严重影响短期预测的精确性。为建立数据质量受损情况下的精确短期预测模型,提出了结合数据预处理和双向长短期记忆(bi-directional long short-term memory,Bi-LSTM)的短期预测框架Bi-LSTM-DP(bi-directional long short-term memory data preprocessing)。在Bi-LSTM-DP中,采集的数据首先通过均值填补缺失值,进而基于Savitzky-Golay滤波器对数据降噪,最后采用Bi-LSTM提取时间序列的信息,实现短期预测。为了评估所提方法的性能,文中使用实测的公开数据集分别预测风电发电量和负荷需求,与其他参考方法对比表明了所述方法的有效性和鲁棒性。展开更多
The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with B...The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.展开更多
The study of the effects of supercritical CO_(2)(ScCO_(2))under high temperature and high pressure on the mechanical properties and fracturing potential of shale holds significant implications for advancing our unders...The study of the effects of supercritical CO_(2)(ScCO_(2))under high temperature and high pressure on the mechanical properties and fracturing potential of shale holds significant implications for advancing our understanding of enhanced shale gas extraction and reservoir exploration and development.This study examines the influence of three fluids,i.e.ScCO_(2),deionized water(DW),and ScCO_(2)tDW,on the mechanical properties and fracturability of shale at immersion pressures of 15 MPa and 45 MPa,with a constant temperature of 100C.The key findings are as follows:(1)Uniaxial compressive strength(UCS)of shale decreased by 10.72%,11.95%,and 23.67%at 15 MPa,and by 42.40%,46.84%,and 51.65%at 45 MPa after immersion in ScCO_(2),DW,and ScCO_(2)tDW,respectively,with the most pronounced effect observed in ScCO_(2)tDW;(2)Microstructural analysis revealed that while ScCO_(2)and DW do not significantly alter the microstructure,immersion in ScCO_(2)tDW results in a more complex surface morphology;(3)Acoustic emission(AE)analysis indicates a reduction in stress for crack damage,with a decreased fractal dimension of AE signals in different fluids.AE energy is primarily generated during the unstable crack propagation stage;(4)A quantitative method employing a multi-factor approach combined with the brittleness index(BI)effectively characterizes shale fracturability.Evaluation results show that ScCO_(2)tDW has a more significant effect on shale fracturability,with fracturability indices of 0.833%and 1.180%following soaking at 15 MPa and 45 MPa,respectively.Higher immersion pressure correlates positively with increased shale fracturability.展开更多
A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural a...A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural air diffusion electrode(NADE)to construct the heterogeneous visible-light-driven photoelectro-Fenton(HEVL-PEF)process to enhance the degradation and mineralization of tetracycline(TC).Interfacial≡Fe sites,OVs and Bi metal were simultaneously constructed via Fe doping,which effectively improved visible light absorption and the separation efficiency of photogenerated carriers to further accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ),achieving Fenton reaction recycling.HE-VL-PEF process could achieve enhanced treatment of pollutants,thanks to the synergistic effect of electro-Fenton(EF)and photo-Fenton(PF).NADE exhibited excellent H_(2)O_(2) electrosynthesis without external oxygen-pumping equipment.Under the irradiation of visible light,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve more photoelectrons to accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ)or directly activate H2O2.DFT calculations also clearly demonstrated that except for the fast charge separation and transfer,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve a faster electron transport between Fe-O,facilitating Fe site acquire more electron.Consequently,the Fe-Bi/Bi_(7)O_(9)I_(3)/OVs in HE-VL-PEF process presented performance superiorities including excellent pollutant removal(91.91%),low electric energy consumption of 66.34 k Wh/kg total organic carbon(TOC),excellent reusability and wide p H adaptability(3–9).展开更多
Ising superconductivity has garnered much attention in recent years due to its extremely high in-plane upper critical field (B_(c2)).Here,we fabricated 14 multilayer Pb_(1-x)Bi_(x) (0%≤x≤40%) thin films on Si (111)-...Ising superconductivity has garnered much attention in recent years due to its extremely high in-plane upper critical field (B_(c2)).Here,we fabricated 14 multilayer Pb_(1-x)Bi_(x) (0%≤x≤40%) thin films on Si (111)-7×7 reconstructed surface by molecular beam epitaxy.Large B_(c2) beyond the Pauli limit is observed in all the Pb_(1-x)Bi_(x) films,indicating that they may exhibit characteristics of Ising superconductivity.Moreover,the introduction of Bi doping can significantly enhance and effectively tune the in-plane B_(c2) of Pb_(1-x)Bi_(x) films,which will help us better understand Ising superconductivity and provide a new platform for the development of tunable Ising superconductors.展开更多
We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney ...We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney method to derive the orbital and physical parameters of the system.The resulting stellar parameters are M1=0.58±0.01M⊙,M2=1.42±0.02M⊙,R1=0.88±0.01R⊙,R2=1.31±0.01R⊙,with an orbital separation of a=2.80±0.01R⊙.Based on all available CCD times of minimum light,including both ground-based and T ESS observations,the(O-C)diagram of BI CVn was analyzed.T he orbital period exhibits a long-term decrease at a rate of-2.3239(±0.0001)×10-8 day yr-1,likely due to mass transfer from the more massive to the less massive component.Superimposed on this trend is a cyclic variation with a period of 56.84±0.08 yr,indicative of a light-travel time effect caused by a third body,whose estimated mass is 0.63±0.02M⊙.Using these derived parameters,we modeled the binary’s evolution through non-conservative processes with the Binary Star Evolution code.The evolutionary tracks of the components were examined in multiple parameter planes,leading to an estimated merger timescale of approximately 2.70 Gyr.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1403201 and 2024YFA1408104)the National Natural Science Foundation of China(Grant Nos.11927809 and 12434004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)。
文摘By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measured near the perimeter of the islands.This feature is very different from the single zero-energy peak observed on some other small Bi islands.The edge states spread towards the inner side of the islands over a width of 2-3 nm.The two edge-state peaks at positive and negative energies move to higher values with the increase of the magnetic field,and they disappear near the transition temperature of FeTe_(0.55)Se_(0.45).Meanwhile,enhanced superconducting gaps are observed in the central regions of these Bi islands,which may be induced by the enhanced pair potential of the topological surface state.Our observations provide a valuable message for the edge state and the proximity-induced superconductivity on specific Bi islands grown on FeTe_(0.55)Se_(0.45)substrate.
文摘短期预测在智能电网建设中扮演着重要角色,深刻影响电网发输变配用各个环节的智能化改造。短期预测一般基于系统实测数据,而传感器故障,数据传输错误等原因会导致数据质量下降,严重影响短期预测的精确性。为建立数据质量受损情况下的精确短期预测模型,提出了结合数据预处理和双向长短期记忆(bi-directional long short-term memory,Bi-LSTM)的短期预测框架Bi-LSTM-DP(bi-directional long short-term memory data preprocessing)。在Bi-LSTM-DP中,采集的数据首先通过均值填补缺失值,进而基于Savitzky-Golay滤波器对数据降噪,最后采用Bi-LSTM提取时间序列的信息,实现短期预测。为了评估所提方法的性能,文中使用实测的公开数据集分别预测风电发电量和负荷需求,与其他参考方法对比表明了所述方法的有效性和鲁棒性。
基金Funded by the National Natural Science Foundation of China(No.52472012)Opening Project of State Silica-Based Materials Laboratory of Anhui Province(No.2022KF11)the Research and Development of Glass Powder for Laser Sealing and Its Sealing Technology(No.K24556)。
文摘The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.
基金financial support from the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC1021)the National Natural Science Foundation of China(Grant No.52231012)+1 种基金the Natural Science Foundation of Hainan Province(Grant No.424QN213)the Scientific Research Foundation of Hainan University.
文摘The study of the effects of supercritical CO_(2)(ScCO_(2))under high temperature and high pressure on the mechanical properties and fracturing potential of shale holds significant implications for advancing our understanding of enhanced shale gas extraction and reservoir exploration and development.This study examines the influence of three fluids,i.e.ScCO_(2),deionized water(DW),and ScCO_(2)tDW,on the mechanical properties and fracturability of shale at immersion pressures of 15 MPa and 45 MPa,with a constant temperature of 100C.The key findings are as follows:(1)Uniaxial compressive strength(UCS)of shale decreased by 10.72%,11.95%,and 23.67%at 15 MPa,and by 42.40%,46.84%,and 51.65%at 45 MPa after immersion in ScCO_(2),DW,and ScCO_(2)tDW,respectively,with the most pronounced effect observed in ScCO_(2)tDW;(2)Microstructural analysis revealed that while ScCO_(2)and DW do not significantly alter the microstructure,immersion in ScCO_(2)tDW results in a more complex surface morphology;(3)Acoustic emission(AE)analysis indicates a reduction in stress for crack damage,with a decreased fractal dimension of AE signals in different fluids.AE energy is primarily generated during the unstable crack propagation stage;(4)A quantitative method employing a multi-factor approach combined with the brittleness index(BI)effectively characterizes shale fracturability.Evaluation results show that ScCO_(2)tDW has a more significant effect on shale fracturability,with fracturability indices of 0.833%and 1.180%following soaking at 15 MPa and 45 MPa,respectively.Higher immersion pressure correlates positively with increased shale fracturability.
基金financially supported by Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)National Key R&D Program International Cooperation Project(No.2021YFE0106500)+3 种基金Natural Science Foundation of China(No.52170085)Fundamental Research Funds for the Central UniversitiesNankai UniversityNational Research Foundation IRGChina/South Africa Research Cooperation Programme(No.132793)。
文摘A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural air diffusion electrode(NADE)to construct the heterogeneous visible-light-driven photoelectro-Fenton(HEVL-PEF)process to enhance the degradation and mineralization of tetracycline(TC).Interfacial≡Fe sites,OVs and Bi metal were simultaneously constructed via Fe doping,which effectively improved visible light absorption and the separation efficiency of photogenerated carriers to further accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ),achieving Fenton reaction recycling.HE-VL-PEF process could achieve enhanced treatment of pollutants,thanks to the synergistic effect of electro-Fenton(EF)and photo-Fenton(PF).NADE exhibited excellent H_(2)O_(2) electrosynthesis without external oxygen-pumping equipment.Under the irradiation of visible light,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve more photoelectrons to accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ)or directly activate H2O2.DFT calculations also clearly demonstrated that except for the fast charge separation and transfer,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve a faster electron transport between Fe-O,facilitating Fe site acquire more electron.Consequently,the Fe-Bi/Bi_(7)O_(9)I_(3)/OVs in HE-VL-PEF process presented performance superiorities including excellent pollutant removal(91.91%),low electric energy consumption of 66.34 k Wh/kg total organic carbon(TOC),excellent reusability and wide p H adaptability(3–9).
基金supported by the National Natural Science Foundation of China (Grant Nos. 12374196, 92165201, and 11634011)the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0302800)+2 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research (Grant No. YSBR-046)the Fundamental Research Funds for the Central Universities (Grant Nos. WK3510000006 and WK3430000003)Anhui Initiative in Quantum Information Technologies (Grant No. AHY170000)。
文摘Ising superconductivity has garnered much attention in recent years due to its extremely high in-plane upper critical field (B_(c2)).Here,we fabricated 14 multilayer Pb_(1-x)Bi_(x) (0%≤x≤40%) thin films on Si (111)-7×7 reconstructed surface by molecular beam epitaxy.Large B_(c2) beyond the Pauli limit is observed in all the Pb_(1-x)Bi_(x) films,indicating that they may exhibit characteristics of Ising superconductivity.Moreover,the introduction of Bi doping can significantly enhance and effectively tune the in-plane B_(c2) of Pb_(1-x)Bi_(x) films,which will help us better understand Ising superconductivity and provide a new platform for the development of tunable Ising superconductors.
基金a project supported by the Scientific and Technological Research Council of Türkiye (TüB?TAK) under grant No.114F166
文摘We present a comprehensive analysis of BI CVn,an eclipsing overcontact binary system.New BVR photometric observations,combined with available spectroscopic data,were analyzed simultaneously using the Wilson–Devinney method to derive the orbital and physical parameters of the system.The resulting stellar parameters are M1=0.58±0.01M⊙,M2=1.42±0.02M⊙,R1=0.88±0.01R⊙,R2=1.31±0.01R⊙,with an orbital separation of a=2.80±0.01R⊙.Based on all available CCD times of minimum light,including both ground-based and T ESS observations,the(O-C)diagram of BI CVn was analyzed.T he orbital period exhibits a long-term decrease at a rate of-2.3239(±0.0001)×10-8 day yr-1,likely due to mass transfer from the more massive to the less massive component.Superimposed on this trend is a cyclic variation with a period of 56.84±0.08 yr,indicative of a light-travel time effect caused by a third body,whose estimated mass is 0.63±0.02M⊙.Using these derived parameters,we modeled the binary’s evolution through non-conservative processes with the Binary Star Evolution code.The evolutionary tracks of the components were examined in multiple parameter planes,leading to an estimated merger timescale of approximately 2.70 Gyr.
