为了评估临界闪光融合频率(critical flicker fusion frequency,CFF)和眼动追踪中的眼睛闭合时间占某一特定时间的百分率(percentage of eyelid closure over the pupil over time,PERCLOS)检测管制疲劳的性能,利用模拟塔台管制软件和...为了评估临界闪光融合频率(critical flicker fusion frequency,CFF)和眼动追踪中的眼睛闭合时间占某一特定时间的百分率(percentage of eyelid closure over the pupil over time,PERCLOS)检测管制疲劳的性能,利用模拟塔台管制软件和眼动仪搭建实验平台,采集被试的CFF、PERCLOS和主观疲劳数据,从疲劳前后指标变化的差异显著性检验,与疲劳的相关性以及受试者工作特征曲线(receiver operating characteristic curve,ROC)3个方面分析探讨了CFF和PERCLOS检测管制疲劳的性能。结果表明:疲劳前后被试的CFF和PERCLOS均差异显著,且与疲劳呈高度显著相关。CFF和PERCLOS检测管制疲劳的效果分别为中等和较好,两者联合可以作为很好的管制疲劳检测指标。展开更多
Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-p...Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.展开更多
简要介绍了新型CPT(Coherent population trapping,相干布局囚禁)原子频标及光频标的基本原理和研究进展。被动型CPT铷原子钟物理部分的目前体积可控制在100cm^3以内,功耗1W左右,其稳定度为4×10^(-11)τ^(-1/2)(τ为测量取样的时...简要介绍了新型CPT(Coherent population trapping,相干布局囚禁)原子频标及光频标的基本原理和研究进展。被动型CPT铷原子钟物理部分的目前体积可控制在100cm^3以内,功耗1W左右,其稳定度为4×10^(-11)τ^(-1/2)(τ为测量取样的时间间隔)。CPT原理的铯原子频标的物理部分体积减小到1cm^3,功率减小到30mW,稳定度为6×10^(-10)τ^(-1/2),成为当今体积最小、功耗最低的原子钟。随着飞秒激光梳状发生器技术的发展,已将传统的谐波光频链的体积从几间实验室缩小到1.2×1.0m^2的光学平台上,它与光频测量技术的结合,使微波频标与光频标联系起来,建立了光钟,它的稳定性可以从现在的10^(-116)的水平提高到10^(-18)乃至10^(-22)水平,成为当前最精密的时间计量仪器。展开更多
文摘为了评估临界闪光融合频率(critical flicker fusion frequency,CFF)和眼动追踪中的眼睛闭合时间占某一特定时间的百分率(percentage of eyelid closure over the pupil over time,PERCLOS)检测管制疲劳的性能,利用模拟塔台管制软件和眼动仪搭建实验平台,采集被试的CFF、PERCLOS和主观疲劳数据,从疲劳前后指标变化的差异显著性检验,与疲劳的相关性以及受试者工作特征曲线(receiver operating characteristic curve,ROC)3个方面分析探讨了CFF和PERCLOS检测管制疲劳的性能。结果表明:疲劳前后被试的CFF和PERCLOS均差异显著,且与疲劳呈高度显著相关。CFF和PERCLOS检测管制疲劳的效果分别为中等和较好,两者联合可以作为很好的管制疲劳检测指标。
基金support from the National Natural Science Foundation of China(Nos.52120105007,51834010)the National Science Fund for Distinguished Young Scholars(No.52222403).
文摘Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.
文摘简要介绍了新型CPT(Coherent population trapping,相干布局囚禁)原子频标及光频标的基本原理和研究进展。被动型CPT铷原子钟物理部分的目前体积可控制在100cm^3以内,功耗1W左右,其稳定度为4×10^(-11)τ^(-1/2)(τ为测量取样的时间间隔)。CPT原理的铯原子频标的物理部分体积减小到1cm^3,功率减小到30mW,稳定度为6×10^(-10)τ^(-1/2),成为当今体积最小、功耗最低的原子钟。随着飞秒激光梳状发生器技术的发展,已将传统的谐波光频链的体积从几间实验室缩小到1.2×1.0m^2的光学平台上,它与光频测量技术的结合,使微波频标与光频标联系起来,建立了光钟,它的稳定性可以从现在的10^(-116)的水平提高到10^(-18)乃至10^(-22)水平,成为当前最精密的时间计量仪器。
