Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that ...Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.展开更多
This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform plana...This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.展开更多
目的分析贵州省40~65岁人群睡眠质量与体质量指数(body mass index,BMI)超标、中心性肥胖、两种肥胖类型共存的关联差异,探讨晚睡和睡眠规律性对该关联的修饰效应。方法基于2022年3—11月贵州省中老年人群睡眠特征及其与慢性病的随访研...目的分析贵州省40~65岁人群睡眠质量与体质量指数(body mass index,BMI)超标、中心性肥胖、两种肥胖类型共存的关联差异,探讨晚睡和睡眠规律性对该关联的修饰效应。方法基于2022年3—11月贵州省中老年人群睡眠特征及其与慢性病的随访研究基线调查的40~65岁体检人群,采用无序多分类logistic回归分析睡眠质量与不同超重/肥胖类型的关系,分层分析探讨不同性别人群晚睡和睡眠规律性对该关联的修饰效应。结果共1101人纳入研究,与正常组比较,睡眠质量差与中心性肥胖呈正向关联(OR=2.12,95%CI:1.41~3.19),男性中睡眠不规律与睡眠质量差同时存在时中心性肥胖发生风险比睡眠不规律或睡眠质量差单独存在时更高(OR=8.57,95%CI:1.20~61.51)。结论睡眠质量差与中心性肥胖呈正向关联,男性中睡眠不规律是睡眠质量差与中心性肥胖关联的效应修饰因子。改善睡眠质量可能有利于减少中心性肥胖,睡眠规律性和睡眠质量的联合干预有助于减少中年男性中心性肥胖的发生风险。展开更多
基金Project supported by the NSAF(Grant No.U1930201)the National Natural Science Foundation of China(Grant Nos.12274331,91836101,and 91836302)+1 种基金the National Key R&D Program of China(Grant No.2018YFA0306504)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302100).
文摘Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.
基金supported by the National Key R&D Program of China under Grant 2023YFB2904703the National Natural Science Foundation of China under Grant 62341110,62371122 and 62322104+1 种基金the Jiangsu Province Basic Research Project under Grant BK20192002the Fundamental Research Funds for the Central Universities under Grant 2242022k30005 and 2242023K5003。
文摘This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.
文摘目的分析贵州省40~65岁人群睡眠质量与体质量指数(body mass index,BMI)超标、中心性肥胖、两种肥胖类型共存的关联差异,探讨晚睡和睡眠规律性对该关联的修饰效应。方法基于2022年3—11月贵州省中老年人群睡眠特征及其与慢性病的随访研究基线调查的40~65岁体检人群,采用无序多分类logistic回归分析睡眠质量与不同超重/肥胖类型的关系,分层分析探讨不同性别人群晚睡和睡眠规律性对该关联的修饰效应。结果共1101人纳入研究,与正常组比较,睡眠质量差与中心性肥胖呈正向关联(OR=2.12,95%CI:1.41~3.19),男性中睡眠不规律与睡眠质量差同时存在时中心性肥胖发生风险比睡眠不规律或睡眠质量差单独存在时更高(OR=8.57,95%CI:1.20~61.51)。结论睡眠质量差与中心性肥胖呈正向关联,男性中睡眠不规律是睡眠质量差与中心性肥胖关联的效应修饰因子。改善睡眠质量可能有利于减少中心性肥胖,睡眠规律性和睡眠质量的联合干预有助于减少中年男性中心性肥胖的发生风险。
