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Intensified haze formation and meteorological feedback by complex terrain in the North China Plain region

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Atmospheric and Oceanic Science Letters 2023年第2期16卷 1-8页

作者： Jingyi Liu Lian Xue Xin Huang Zilin Wang sijia lou Aijun Ding School of Atmospheric Sciences Nanjing UniversityNanjingChina Jiangsu Provincial Collaborative Innovation Center for Climate Change NanjingChina Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjingChina

华北平原地区冬季雾霾污染频发,本研究结合地面观测,卫星反演和大气动力-化学耦合模拟发现,该地区复杂地形加剧了细颗粒物污染及其与大气边界层之间的相互作用.一方面,复杂地形导致污染在山麓平原积聚,加强迎风坡上升气流.在污染事件中... 详细信息

华北平原地区冬季雾霾污染频发,本研究结合地面观测,卫星反演和大气动力-化学耦合模拟发现,该地区复杂地形加剧了细颗粒物污染及其与大气边界层之间的相互作用.一方面,复杂地形导致污染在山麓平原积聚,加强迎风坡上升气流.在污染事件中,污染层易被抬升至1-2公里高度,高空较强的氧化能力利于二次气溶胶生成;另一方面,地形导致的污染层抬升和二次生成进一步加强气溶胶-边界层相互作用,削弱垂直扩散并加剧近地面大气污染.

关键词： PM_(2.5) 复杂地形二次污染气溶胶-边界层相互作用

The effects of irregular shifts on mood, sleep and hormone levels in an isolated, confined and extreme(ICE) environment

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The effects of irregular shifts on mood, sleep and hormone l...

中国睡眠研究会第十四届全国学术年会

作者： sijia lou Sifan Hu Jie Chen Yun Chen Anqi Zhang Yupeng Guo Jianjun Hou Weimin Dang Hongqiang Sun Peking University Sixth Hospital Peking University Health Science Center

Objective: When performing mission in ICE environments such as aerospace, submarines, and polar environments, humans often face physical and psychological challenges. In the long-term ICE environment, a third-quarter phenomenon was found where mood levels worsened after the midpoint of the mission and partially recovered before the end of the mission. We explore psychological and physical changes in ICE environment with multiple stressors, as well as observe whether there is the third-quarter phenomenon in the short ***: Three male subjects participated in 42 days of confined isolation, where time was delayed by 4 hours for the first four days(D1-D4) to establish and adapt to new circadian rhythm under the experimental conditions, followed by 38 consecutive days of irregular shift work(D5-D42). We measured salivary cortisol and melatonin, visual analog scales(VAS) on mood at adapt stage(AS,D3-D4), early stage(ES, D12-D13), mid stage(MS,D19-20), and late stage(LS,D33-D34) every 4 hour except sleep time. Polysomnography(PSG) was used to record sleep through the night before entering a closed environment, MS, and LS. Subjects wore actigraphy and kept sleep diaries during confined isolation. The Friedman test was used to detect differences in across multiple stages. The area under the curve(AUC) was used to compare hormone levels at each ***: The Area under the curve with respect to ground(AUCg) of cortisol and melatonin at MS was significantly higher than that of LS(χ2 =3.667 p=0.045, χ2=2.846 p=0.027). There was no significant difference in mood in same time point at different stages. There was no significant difference in mood at same stage in different time points. PSG found that N2% and the number of arousals were significantly higher at MS than before irregular shifts in the ICE environment(χ2=6.000 p=0.05, χ2=6.000 p=0.05). No significant differences were found in actigraphy and sleep diaries at each ***: There is a stage-changing

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Sleep and cortisol changes in crews with irregular shifts during a 42-day isolated, confined and extreme environment mission

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Sleep and cortisol changes in crews with irregular shifts du...

中国睡眠研究会第十五届全国学术年会

作者： sijia lou Sifan Hu Jie Chen Yun Chen Anqi Zhang Yupeng Guo Jianjun Hou Weimin Dang Hongqiang Sun Peking University Sixth Hospital Peking University Health Science Center

Background: Humans often face physical and psychological challenges, when carrying out missions in isolated, confined and extreme(ICE) environments such as aerospace, submarines, and arctic conditions.A third-quarter phenomenon was discovered in the long-term ICE environment, where mood levels dropped after the midpoint of the mission and somewhat recovered before the end of the *** explore cortisol, sleep and mood changes in ICE environment involving numerous stressors, as well as whether the thirdquarter phenomenon exist in the ***: Three males participated in 42 days of confined isolation, during which time was delayed by four hours for the first four days(D1-D4) to establish and adapt to new circadian rhythm under experimental *** was followed by 38 consecutive days of irregular shift work(D5-D42).Throughout the study, we measured salivary cortisol and visual analog scales(VAS) on mood at adaptation stage(AS, D3-D4), early stage(ES, D12-D13), mid-stage(MS, D19-20), and late stage(LS, D33-D34).The data were collected every 4 hours, except during sleep ***(PSG) was used to record sleep on the night before entering the closed environment, during the mid-stage, and during the late *** maintained sleep diaries throughout the period of confined *** Friedman test was used to detect differences across multiple *** area under the curve(AUC) was used to compare cortisol levels at each ***: The Area under the curve with respect to ground(AUCg) of cortisol was significantly higher at MS than at LS(χ2=2.846 p=0.027).There were no significant differences in mood between different stages at the same time point or within the same stage at different time *** indicated that the percentage of N2 sleep stage and the number of microarousals were significantly higher at the mid-stage compared to before the onset of irregular shifts in the ICE environment(χ2=6.000 p=0.05, χ2=6.000 p=0.05).No s

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Decadal trend and interannual variation of outflow of aerosols from East Asia: Roles of variations in meteorological parameters and emissions

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Decadal trend and interannual variation of outflow of aeroso...

第31届中国气象学会年会

作者： Yang Yang Hong Liao sijia lou State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences

We apply a global three‐dimensional Goddard Earth Observing System(GEOS)chemical transport model(GEOS‐Chem)to quantify the decadal trend and interannual variation of aerosol outflow from East *** of aerosols are performed for years 1986–2006,driven by the NASA/GEOS‐4 assimilated meteorological *** impacts of variations in meteorological parameters and emissions are imposed separately and together by numerical *** variations in both meteorological parameters and anthropogenic emissions,simulated annual outflow of PM2.5(sum of sulfate,nitrate,ammonium,black carbon,and organic carbon)from East Asia increased by 6.0 Tg(or 53%)over years 1986–2006,in which the outflow fluxes of sulfate,nitrate,and ammonium aerosols had the largest contributions with decadal trends of+1.2,+0.8,and+0.7Tg decade-1,*** outflow fluxes of aerosols also exhibited large interannual variations;the absolute percent departure from the mean(APDM)values of the annual outflow fluxes of sulfate,nitrate,ammonium,black carbon,organic carbon,and PM2.5 were 5.9%,7.9%,5.4%,5.8%,4.2%,and 5.2%,respectively,as variations in both meteorological parameters and anthropogenic emissions were *** sensitivity studies show that,for outflow fluxes of aerosols from East Asia,the decadal trends were driven by variations in anthropogenic emissions whereas the interannual variations were dominated by variations in meteorological *** increases in anthropogenic emissions alone explained about 86%of the decadal trend in outflow of *** variations in meteorological parameters can influence the interannual variations in aerosol outflow by changing both aerosol concentrations over East Asia and zonal winds,the latter is identified to be the key factor because of the high positive correlation coefficient between the annual outflow flux of PM2.5 and zonal wind at 700 hPa(the altitude with the maximum outflow fluxes)for years1986–2006.

关键词： Decadal trend and interannual variation of outflow of aerosols from East Asia Roles of variations in meteorological parameters and emissions

Laboratory Polysomnography Revealed the First-Night Effect in Patients with Insomnia Disorder

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Laboratory Polysomnography Revealed the First-Night Effect i...

中国睡眠研究会第十四届全国学术年会

作者： Sifan Hu Jie Chen Guo Yupeng Yun Chen sijia lou Anqi Zhang Yuezhen Li Yan Shao Ping Yao Lin Lu Xiangdong Tang Hongqiang Sun Peking University Sixth Hospital Beijing Tian Tan Hospital Capital Medical University The Third Hospital of Inner Mongolia Autonomous Region West China Hospital Sichuan University

Background: Guidelines for single night versus consecutive recordings in a sleep laboratory have been disputed mainly due to being existed the first night effect. The first night effect remains a crucial issue in the studies on sleep or sleep disorders. However, these studies yielded heterogenous results. In the present study, we aimed to assess the first night effect on individuals with ***: Polysomnographic recordings in the sleep laboratory were performed for two consecutive nights among thirty-nine patients with Insomnia and age-and sex-matched to thirty-five healthy controls. Sleep variables and sleep architecture of both consecutive two nights were compared and analyzed. Sleep dairy and questionnaires focused on sleep, medical, psychological, and health history were ***: Insomnia and healthy controls demonstrated differentially poor sleep on laboratory adaptation after exposure to a new environment in the sleep lab, and found that these individuals with Insomnia was characterized by longer REM latency in the first night compared with second sleep laboratory night(p 0.05).Conclusions: The first night effect may be exhibited in Insomnia and healthy controls in a new environment, which seemed more pronounced in the healthy controls group. Patients with insomnia have relatively less change in sleep adaptation.

关键词： Insomnia disorder First-night effect REM latency Polysomnography

Multimodal separation for ultrasonic Lamb wave using independent component analysis in the time-frequency domain

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Chinese Journal of Acoustics 2021年第4期40卷 583-596页

作者： lou sijia LIU Zhenli XU Kailiang TRAN Tho N.H.T. ZHOU Chang LE Lawrence H. TA De'an Center for Biomedical Engineering Fudan UniversityShanghai 200433 Academy for Engineering and Technology Fudan UniversityShanghai 200433 Ningbo Marvoto Intelligent Technology Ningbo 315300 Department of Radiology and Diagnostic Imaging University of Alberta EdmontonCanada T6G2R3

Aiming at facilitating Lamb wave signal analysis and mode characterization,an ultrasonic-Lamb wave niultimodal separation method combining short-time Fourier transform(STFT)and independent component analysis(ICA)was *** signals were projected into the time-frequency domain through *** that the energy trajectory of each Lamb mode is indepenclent in the time-frequency domain,ICA method was then applied to separate tlie superposed *** group velocity curve of each mode was extracted according to its time-frequency energy trajectory,based on which the plate thickness can be further *** finite-difference time-domain(FDTD)simulated signals and experimental signals for a 1 nmi-thick steel plate were used to validate the performance of the proposed *** three fundainental Lamb modes,A0,SO and A1 modes were *** average errors of group velocity estimation in the simulation and experiment were about 1.5%and 2.0%,with that of plate thickness estimation being 0.3%and 2.0%*** simulated results indicate that,when the signal-to-noise ratio(SNR)is larger than 0 dB,the ICA method in the time-frequency domain can be used for ultrasonic Lamb wave multimodal separation,group velocity extraction and plate thickness estimation.

关键词： separation wave analysis

The influence of placebo-related effects on the first night effect in patients with chronic insomnia

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The influence of placebo-related effects on the first night ...

中国睡眠研究会第十一届全国学术年会

作者： Sifan Hu Jie Chen sijia lou Xiaoxia Zhao Hongqiang Sun Peking University Sixth Hospital

Objective In sleep laboratory studies,the first-night effect（FNE） refers to the well-known phenomenon resulting from an individual maladaptation to the new environment. However,there have been rarely reports of the methods to attenuate the occurrence of the FNE. In this study, we aimed to investigate the effects of the placebo on the FNE in patients with chronic insomnia. Methods Thirty-six patients with chronic insomnia and 25 good sleeper controls（GSC） were enrolled in this study. Sixteen patients with chronic insomnia（39.75±14.63 years） were given two days placebo intervention（placebo-administration group,（PL））, and twenty patients with chronic insomnia（39.90±10.27 years）（drug-free group（DF）） and 25 GSC（37.72±8.45 years） were not given any interventions. We analyzed polysomnographic data and subjective data from two consecutive nights of in-laboratory study to clarify the placebo-related effects. Results The current sample consisted of 16 patients with chronic insomnia（39.75±14.63 years） who were given two days placebo intervention（placebo administration group, PL）, 20 patients with chronic insomnia（39.90±10.27 years）（drug-free group, DF） and 25 GSC（good sleeper group）（37.72±8.45 years） who were not given placebo administration. No significant difference for the age, gender distribution, years of education and score of Frost’s Multidimensional Perfectionism Scale（FMPS） among the PL, DF and GSC group（all p＞0.05）. There were no significant differences for total disease course and insomnia severity index（ISI） score between the PL and DF group（both p＞0.05）.The results demonstrated most participants showed a FNE（43.75%） rather than experienced no change across night（37.50%） in the PL group. Compared with second night, the first night presented a longer REM Sleep Latency（REML）, more REM（percentage）, a longer self-reported SOL, more self-reported WASO and less self-reported TST in the PL group（p＜0.05）. In the first sleep lab night, compared with the DF group, Sleep Onse

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中国近地面PM_(2.5)质量浓度卫星遥感数据集比较及历史趋势分析

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大气与环境光学学报 2022年第6期17卷 613-629页

作者：戴刘新张莹李正强漏嗣佳中国科学院空天信息创新研究院国家环境保护卫星遥感重点实验室北京100101 中国科学院大学资源与环境学院北京100049 南京大学大气科学学院大气与地球系统科学国际合作联合实验室江苏南京210023

随着对大气污染问题的日益重视,监测大气颗粒物质量浓度也成为了热门研究领域。针对现行两种流行算法(基于模式模拟和基于机器学习)产生的近地面PM_(2.5)质量浓度科学数据集进行了比较分析,利用城市年均PM_(2.5)监测数据定量评估两数据... 详细信息

随着对大气污染问题的日益重视,监测大气颗粒物质量浓度也成为了热门研究领域。针对现行两种流行算法(基于模式模拟和基于机器学习)产生的近地面PM_(2.5)质量浓度科学数据集进行了比较分析,利用城市年均PM_(2.5)监测数据定量评估两数据集的不确定性,并通过空间自相关分析对两数据集的空间合理性进行了评价。同时,还利用标准差椭圆分析研究了2000–2018年间主要污染区域(北京、天津、河北、河南、山西、山东等地)PM_(2.5)的时空演变趋势。结果表明,基于机器学习算法产生的数据集(CHAP)具有较高的精度,适用于区域性空气质量研究;而基于模式模拟算法产生的数据集(vanDonkelaarA)具有合理的空间分布,更适合于大尺度、长时间的污染趋势分析。由标准差椭圆分析发现,2000–2018年研究区域标准差椭圆中心的位置整体向东北方向移动;2013年前PM_(2.5)分布范围及年均值在波动中呈现整体上升的趋势,随后显著下降,造成PM_(2.5)浓度下降的主要因素是有效管控措施的实施。研究结果为中国区域的细颗粒物污染研究的数据集选取提供了参考依据,为大气细颗粒物污染的防控提供科学支撑。

关键词： PM_(2.5) 卫星遥感标准差椭圆空间自相关

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多用户对多中继双向通信系统中继选择与功率分配策略

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电信科学 2014年第1期30卷 50-56页

作者：楼思嘉杨龙祥南京邮电大学南京210003 江苏省无线通信重点实验室南京210003

针对多用户对多中继双向通信系统,提出了一种中继选择与功率分配联合算法,目的是改进系统的误码率性能和降低系统的运算复杂度。所提出的新型联合算法为每对用户节点选择出最佳中继,最佳中继将接收到的信息进行网络编码后向所有节点广播... 详细信息

针对多用户对多中继双向通信系统,提出了一种中继选择与功率分配联合算法,目的是改进系统的误码率性能和降低系统的运算复杂度。所提出的新型联合算法为每对用户节点选择出最佳中继,最佳中继将接收到的信息进行网络编码后向所有节点广播,联合算法也对每个节点的发送功率进行分配。建立了新型联合算法下系统的误码率闭合表达式,并验证了解析分析的正确性。结果表明,与传统的等功率发送算法相比,本文的联合算法可以获得更好的误码率性能。

关键词：多用户对多中继双向信道解码前传中继选择功率分配端到端误比特率