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A New Method to Identify the Maximum time interval between Individual Events in Compound Rainstorm and Heatwave Events

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International Journal of Disaster Risk Science 2024年第3期15卷 453-466页

作者： Junlin Zhang Wei Xu Yu Qiao Xinli Liao Chenna Meng Qinmei Han Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education Faculty of Geographical Science Beijing Normal University Academy of Disaster Reduction and Emergency Management Ministry of Emergency Management and Ministry of Education Beijing Normal University State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University National Climate Center China Meteorological Administration

Growing evidence indicates that extreme heat and rain may occur in succession within short time periods and cause greater impacts than individual events separated in time and space. Therefore, many studies have examined the impacts of compound hazard events on the social-ecological system at various scales. The definition of compound events is fundamental for such research. However, there are no existing studies that support the determination of time interval between individual events of a compound rainstorm and heatwave(CRH) event, which consists of two or more potentially qualifying component heatwave and rainstorm events. To address the deficiency in defining what individual events can constitute a CRH event, this study proposed a novel method to determine the maximum time interval for CRH events through the change in CRH event frequency with increasing time interval between individual events, using southern China as a case study. The results show that the threshold identified by the proposed method is reasonable. For more than 90% of the meteorological stations, the frequency of CRH events has reached a maximum when the time interval is less than or equal to the threshold. This study can aid in time interval selection, which is an important step for subsequent study of CRH events.

关键词： Compound extreme weather event Rainstorm and heatwave Southern China Threshold time interval

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Climate warming shifts the time interval between flowering and leaf unfolding depending on the warming period

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Science China(Life Sciences) 2022年第11期65卷 2316-2324页

作者： Shuxin Wang Zhaofei Wu Yufeng Gong Shubiao Wang Wei Zhang Shanshan Zhang Hans J.De Boeck Yongshuo H.Fu College of Water Sciences Beijing Normal UniversityBeijing 100085China Beijing Zoo Beijing 100044China Plants and Ecosystems Department of BiologyUniversity of AntwerpAntwerpAntwerpen 2000Belgium

The timing of flowering(FL)and leaf unfolding(LU)determine plants’reproduction and vegetative *** warming has substantially advanced FL and LU of temperate and boreal plants,but their responses to warming differ,which may influence the time interval between FL and LU(ΔLU-FL),thereby impacting plant fitness and intraspecific physiological *** on twigs collected from two flowering-first tree species,Populus tomentosa and Amygdalus triloba,we conducted a manipulative experiment to investigate the effects of winter chilling,spring warming and photoperiod on theΔ*** found that photoperiod did not affect theΔLU-FL of Amygdalus triloba,but shortenedΔLU-FL by 5.1 d of Populus ***,spring warming and winter chilling oppositely affected theΔLU-FL of both ***,low chilling accumulation extended theΔLU-FL by 3.8 and 9.4 d for Populus tomentosa and Amygdalus triloba,but spring warming shortened theΔLU-FL by 4.1 and 0.2 d℃^(-1).Our results indicate that climate warming will decrease or increase theΔLU-FL depending on the warming periods,i.e.,spring or *** shifted time interval between flowering and leaf unfolding may have ecological effects including affecting pollen transfer efficiency and alter the structure and functioning of terrestrial ecosystem.

关键词： chilling flowering leaf unfolding photoperiod spring phenology time interval warming period

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Deterministic and complete hyperentangled Bell states analysis assisted by frequency and time interval degrees of freedom

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Frontiers of physics 2022年第5期17卷 149-157页

作者： Xin-Jie Zhou Wen-Qiang Liu Hai-Rui Wei Yan-Bei Zheng Fang-Fang Du School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements(MOE) School of PhysicsBeijing Institute of TechnologyBeijing 100081China Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan 030051China

Hyperentangled Bell states analysis(HBSA)is an essential building block for certain hyper-parallel quantum information *** propose a complete and deterministic HBSA scheme encoded in spatial and polarization degrees of freedom(DOFs)of two-photon system assisted by a fixed frequency-based entanglement and a time interval *** parity information the spatial-based and polarization-based hyper-entanglement can be distinguished by the distinct time intervals of the photon pairs,and the phase information can be distinguished by the detection *** with previous schemes,the number of the auxiliary entanglements is reduced from two to one by introducing time interval ***,the additional frequency and time interval DOFs suffer less from the collective channel noise.

关键词： hyperentangled Bell states analysis multiple degrees of freedom time interval

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time interval APPROACH TO THE PULSED NEUTRON LOGGING METHOD

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Nuclear Science and Techniques 1994年第2期5卷 118-123页

作者：赵经武苏为宁 DepartmentofPhysics NanjingUniversityNanjing210008China DepartmentofPhysics NanjingUniversityNanji

The time interval of neibouring neutrons emitted from a steady state neutron source can be treated as that from a time-dependent neutron source. In the rockspace, the neutron flux is given by the neutron diffusion equation and is composedof an infinite number of 'modes'. Each 'mode' is composed of two die-away *** delay action has been discussed and used to measure the time interval withonly one detector in the experimellt. Nuclear reactions with the time distributiondue to different types of radiations observed in the neutron well-logging methods arepresented with a view to getting the rock nuclear parameters from the time intervaltechnique.

关键词： time interval Steady state neutron source Delay action Neutronlogging method

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Vitreoretinal surgeons'experience and time interval from pars-plana vitrectomy to cataract extraction

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International Journal of Ophthalmology(English edition) 2021年第1期14卷 120-126页

作者： Yan-Xin Xu Liang-Ping Liu Jian-Bing Li Huan-Huan Cheng Min Hou Lin Lu Ming-Xing Wu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangzhou 510060Guangdong ProvinceChina

AIM:To identify the association of the vitreoretinal surgeons'experience with the time interval between parsplana vitrectomy(PPV)and cataract extraction(CE).METHODS:Eyes with prior PPV and following CE were included in this retrospective cohort *** years of practice and the annual case volume were used to describe the surgeons'*** linear regression analysis was used to investigate the relationship between surgeons'experience and the time interval adjusted for the patients age,gender,intraocular tamponade,and case ***:Of 132430 eyes,1445 eyes were included in this *** multivariable linear regression analysis,cases performed by surgeons with>20 practice years had longer time intervals compared with surgeons withtime interval was detected for comparing the lowest with the highest volume groups(β=0.089,95%CI:-0.164 to 0.343,P=0.343).The surgeons'practice years were not directly with the *** complicated surgery,the higherpractice-year surgeons had longer time interval than lowerpractice-year ***:The time intervals from PPV to CE is longer in higher-practice-year *** surgeons'practice years may have a greater effect on the time interval than annual case volume in high-complexity *** the complexity of vitreoretinal diseases with the surgeons'practice year should be considered.

关键词： pars-plana vitrectomy cataract time interval experience annual case volume

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The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis:a retrospective observational study

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Neural Regeneration Research 2025年第5期20卷 1505-1512页

作者： Jieying Wu Shan Ye Xiangyi Liu Yingsheng Xu Dongsheng Fan Department of Neurology Peking University Third HospitalBeijingChina Beijing Municipal Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases BeijingChina Key Laboratory for Neuroscience National Health Commission/Ministry of EducationPeking UniversityBeijingChina

Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor *** bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to ***,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is *** address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral *** used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis *** factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,Pinterval until bilateral limb *** results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis *** findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.

关键词： amyotrophic lateral sclerosis bilateral limb involvement Cox proportional hazards regression model horizontal spread restricted cubic spline analysis time interval upper motor neuron vertical spread

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Influences of different time intervals between loop electrosurgical excision and abdominal hysterectomy or radical hysterectomy on postoperative complications: a retrospective analysis

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Journal of Medical Colleges of PLA(China) 2010年第1期25卷 38-43页

作者： Qu Haina Zhang Yan Zhang Junjie Hui Ning Xu Mingjuan Department of Obstetrics and Gynecology Changhai Hospital Second Military Medical University Shanghai 200433 China

Objective： To study the influences of different time intervals between loop electrosurgical excision （LEEP） and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods： Sixty-eight patients, who received subsequent abdominal hysterectomy or radical hysterectomy after LEEP due to C1N III and cervical cancer （IA1, IA2 and IB1）, were included in the present study. The hospital and clinic records of these patients were reviewed. The patients were divided into three groups according to the time intervals between LEEP and hysterectomy or radical hysterectomy： group l（within 48 h）, group 2 （between 48 h to 6 weeks）, and group 3（〉 6 weeks ）.Results： General characteristics of patients, including the mean age, delivery history, BMI, menopausal status, clinical stage and HPV infection, were comparable between patients of different groups. There were no significant differences in the mean transfusion amount, posthysterectomy hospital stay or operation time between different groups. The frequencies and spectrum of complications were not significantly affected by the time interval between LEEP and hysterectomy or radical hysterectomy. Conclusion： It is concluded that whenever the LEEP is done, the operation including hysterectomy or radical hysterectomy can be conducted at any time as it is necessary for the patients.

关键词： LEEP Hysterectomy Radical hysterectomy time interval CIN III Early cervical cancer

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Evolution of the Pulse Width in Dielectric Barrier Atmospheric Pressure Discharge

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Plasma Science and Technology 2012年第9期14卷 808-812页

作者：宋新新谭震宇陈波张远涛李清泉 School of Electrical Engineering Shandong University Shandong Labour Vocational and Technology College

A study of the evolution of the pulse width in homogeneous dielectric barrier dis- charge at atmospheric pressure with helium as the working gas is reported by using a one- dimensional fluid model. In this paper, a new computational method is presented to estimate the pulse width through calculating the time interval between the breakdown voltage and the extinguishing voltage. The effects on the discharge characteristics of the applied voltage and exci- tation frequency are studied based on the computational data. The results of the simulation show that the pulse width is observed to be narrower and the time intervals between two consecutive current pulses decrease with increasing amplitude and excitation frequency, which indicates that the homogeneous discharge is susceptible to the filamentary mode. The simulation results support the conclusion that in order to restrain the transition from the glow mode to filamentary mode, the applied voltage and excitation frequency should be kept within an appropriate range.

关键词： pulse width time interval breakdown voltage extinguishing voltage glowmode filamentary mode

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A hybrid-type quantum random number generator

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Chinese Physics B 2016年第5期25卷 49-52页

作者：马海强朱武韦克金李瑞雪刘宏伟 School of Science and State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

This paper proposes a well-performing hybrid-type truly quantum random number generator based on the time interval between two independent single-photon detection signals, which is practical and intuitive, and generates the initial random number sources from a combination of multiple existing random number sources. A time-to-amplitude converter and multichannel analyzer are used for qualitative analysis to demonstrate that each and every step is random. Furthermore, a carefully designed data acquisition system is used to obtain a high-quality random sequence. Our scheme is simple and proves that the random number bit rate can be dramatically increased to satisfy practical requirements.

关键词： true random number generator single photon counting time interval

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Experiment and analysis on microscopic characteristics of pedestrian movement in building bottleneck

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Science China(Technological Sciences) 2011年第7期54卷 1730-1736页

作者： TIAN Wei SONG WeiGuo LU Wei FANG ZhiMing State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230027 China

In this paper, evacuation experiments are carried out to study pedestrian movement behaviors in building bottleneck. An image processing method based on mean-shift algorithm is used to extract pedestrian movement trajectory. Based on the extracted trajectory, we analyze the microscopic movement characteristics of pedestrians such as lane formation, change of velocity and distance between two sequential pedestrians. A pedestrian lane is a group of pedestrians moving in a column. The lane formation is verified by the pedestrian trajectory and distribution of pedestrian’s lateral positions (x direction in the paper): lane number changes from one to two, three or even more with the increasing bottleneck width when pedestrians pass through the bottleneck. By analyzing the pedestrian movement behaviors in the same pedestrian lane, we find three typical movement modes in the bottleneck: time-lag acceleration, synchronous acceleration, and avoiding deceleration. Through analyzing the time intervals when successive pedestrians pass through the bottleneck, we find that most pedestrians adjust their velocities according to the distance to the forward pedestrians. Results also indicate that due to different cultures, pedestrians flux in China and Germany may have some differences besides their similarities.

关键词： evacuation trajectory Mean-shift algorithm pedestrian lane time interval

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