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Evaluation of 3D crustal seismic velocity models in southwest China:Model performance,limitation,and prospects

Science China Earth Sciences 2024年第2期67卷 604-619页

作者： Xin WANG Ling chen qi-fu chen Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China

Southwest China is a tectonically and seismically active region,witnessing strong deformation due to the collision between the Indian and Eurasian *** the subsurface velocity structure of this region is thus important in understanding the tectonics and geodynamic processes of continental collision and in mitigating seismic *** studies have provided various 3D seismic velocity models in southwest ***,discrepancies exist among these models,and less effort has been made to quantify the reliability and accuracy of these existing velocity *** this study,we use regional 3D waveform simulation to evaluate the performance of various regional crustal 3D velocity models in reproducing observed *** particularly focus on two recent earthquake sequence in the region,the 2021 Yunnan Yangbi MS_(6.4) earthquake sequence and the 2022 Sichuan Luding MS_(6.8) earthquake *** tested 3D velocity models include the Southwest China Community Velocity model V1.0,the Unified Seismic Tomography Models for Continental China Lithosphere V2.0,the adjoint full waveform tomography model of the crustal and upper mantle beneath Eastern Tibetan Plateau,and the shallow seismic structure model beneath continental *** results show that the tested 3D velocity models generally capture well long-period(full-waveform tomography model shows a slighter better performance than the other models,especially for the body-waves,highlighting the advantages

关键词： Southwest China Seismic tomography models Shallow Structures Waveform simulation Model evaluation

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Overview of deep structures under the Changbaishan volcanic area in Northeast China

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Science China Earth Sciences 2019年第6期62卷 935-952页

作者： qi-fu chen Yinshuang AI Yun chen Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences Institutions of Earth Science Chinese Academy of Sciences State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences

The Changbaishan volcano is an active and considerably hazardous volcano located on the border of China and North Korea. This paper summarizes a series of geophysical surveys as well as seismological and volcano-observational networks around the Changbaishan volcanic area. We characterize deep structures related to the Changbaishan volcanic area. The prominent low-velocity anomalies and low-resistance bodies associated with the magma system under the Changbaishan volcano were detected in the crust and upper mantle, and high-velocity anomalies were imaged within the mantle transition zone,suggesting that the origin of the Changbaishan volcano is related to the subducted Pacific slab. However, there exist a few major obstacles for comprehensively elucidating the deep structure of the Changbaishan volcano as well as for the preparedness for and response toward future volcanic unrest and activity. It is essential to collect data from both China and Korean Peninsula to image the deep structure beneath the Changbaishan volcanic area. A multi-disciplinary approach comprising seismological investigations, deformation information from GNSS and InSar, and gravity and magnetotelluric surveying is a reliable manner for imaging high-resolution structures and fluid movement for the spatial distribution and variation of the volcanic magma *** effective volcano-monitoring network system is considerably important to improve hazard assessments and characterize the potential future eruption of the Changbaishan volcano.

关键词： Changbaishan volcano Deep structure Geophysical observation

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Applications of the Hilbert-Huang Transform for Microtremor Data Analysis Enhancement

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Journal of Earth Science 2015年第6期26卷 799-806页

作者： Lanbo Liu Robert Mehl Weijun Wang qi-fu chen Department of Civil & Environmental Engineering University University of Connecticut Center for Integrative Geosciences University of Connecticut Institute of Earthquake Science China Earthquake Administration

In this paper we discuss the use of the Hilbert-Huang transform（HHT） to enhance the time-frequency analysis of microtremor measurements. HHT is a powerful algorithm that combines the process of empirical mode decomposition（EMD） and the Hilbert transform to compose the HilbertHuang spectrum that contains the time-frequency-energy information of the recorded signals. HHT is an adaptive algorithm and does not require the signals to be linear or stationary. HHT is advantageous for analyzing microtremor data, since observed microtremors are commonly contaminated by nonstationary transient noises close to the recording instruments. This is especially true when microtremors are measured in an urban environment. In our data processing HHT was used to（1） eliminate the unwanted short-duration transient constituents from microtremor data and use only the coherent portion of the data to carry out the widely used horizontal to vertical spectral ratio（H/V） method;（2） identify and eliminate the continuous industrial noise in certain frequency band; and（3） enhance the H/V analysis by using the Hilbert-Huang spectrum（HHS）. The efficacy of this proposed approach is demonstrated by the examples of applying it to microtremor data acquired in the metropolitan Beijing area.

关键词： Hilbert-Huang transform microtremor time-frequency HN engineering earthquake.

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Ambient noise as the new source for urban engineering seismology and earthquake engineering: a case study from Beijing metropolitan area

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Earthquake Science 2014年第1期27卷 89-100页

作者： Lanbo Liu qi-fu chen Weijun Wang Eric Rohrbach Department of Civil & Environmental Engineering University of Connecticut Institute of Earthquake Science China Earthquake Administration Institute of Geology and Geophysics Chinese Academy of Sciences

In highly populated urban centers, traditional seismic survey sources can no longer be properly applied due to restrictions in modern civilian life styles. The ambient vibration noise, including both microseisms and microtremor, though are generally weak but available anywhere and anytime, can be an ideal supplementary source for conducting seismic surveys for engineering seismology and earthquake engineering. This is funda- mentally supported by advanced digital signal processing techniques for effectively extracting the useful information out from the noise. Thus, it can be essentially regarded as a passive seismic method. In this paper we first make a brief survey of the ambient vibration noise, followed by a quick summary of digital signal processing for passive seismic surveys. Then the applications of ambient noise in engi- neering seismology and earthquake engineering for urban settings are illustrated with examples from Beijing metro- politan area. For engineering seismology the example is the assessment of site effect in a large area via microtremor observations. For earthquake engineering the example is for structural characterization of a typical reinforced con- crete high-rise building using background vibration *** showing these examples we argue that the ambient noise can be treated as a new source that is economical, practical, and particularly valuable to engineering seis- mology and earthquake engineering projects for seismic hazard mitigation in urban areas.

关键词： Ambient noise Resonance frequency -Ground motion amplification Seismic vulnerability ~Horizontal to vertical spectra/ratio (HVSR) ~Seismic interferometry (SI) ~ Beijing metropolitan area

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Earthquake damage and loss estimation with Geographic Information System

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Acta Seismologica Sinica(English Edition) 1998年第6期11卷 95-102页

作者： YONG chen GE PING LI qi fu chen LING chen MIN FENG LI Center for Analysis and Prediction, China Seismological Bureau, Beijing 100036, China 1. Center for Analysis and Prediction China Seismological Bureau 100036 Beijing China

The present paper first includes a brief discussion of GIS technology. Next, the various steps in a regional earthquake damage and loss analysis are discussed, with emphasis on their implementation in the GIS environment. Lastly, a software of WorldRisk which was completed recently are presented to illustrate GIS based global earthquake damage and loss estimation.

关键词： GIS earthquake damage loss estimation

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Cidan Capsule in Combination with Adjuvant Transarterial Chemoembolization Reduces Recurrence Rate after Curative Resection of Hepatocellular Carcinoma:A Multicenter,Randomized Controlled Trial

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Chinese Journal of Integrative Medicine 2023年第1期29卷 3-9页

作者： ZHENG Dong-hai YANG Jia-mei WU Jian-xiong chenG Shu-qun ZHANG Shao-geng WU Dong LI Aijun fu Xiao-hui LI Xun qi fu-chen DUAN Wei-hong chen Jun-hui YANG Zhi-ying LIANG Lu ZENG Jin-xiong ZHENG Wei-da WU Meng-chao Department of Oncology Beijing Weida Traditional Chinese Medicine Cancer HospitalBeijing100023China Department of Hepatic Surgery the Third Affiliated Hospital of Naval Medical UniversityShanghai200433China Department of Abdominal Surgery Cancer Hospital of Chinese Academy of Medical SciencesBeijing100021China Department of Hepatic Surgery the Fifth Medical Center of PLA General HospitalBeijing100161China Department of Hepatic Surgery the First Hospital of Lanzhou UniversityLanzhou730013China Department of Hepatic Surgery Huai’an First People’s HospitalNanjing Medical UniversityHuai’anJiangsu Province223399China Department of Hepatic Surgery PLA Rocket Army General HospitalBeijing100088China Department of Interventional Therapy Shenzhen Hospital of Peking UniversityShenzhenGuangdong Province518036China Department of Hepatic Surgery China-Japan Friendship HospitalBeijing100029China Department of Hepatic Surgery Baotou Central HospitalBaotouInner Mongolia Autonomous Region014042China Department of Traditional Chinese Medicine No.900 Hospital of the Joint Logistics Support Force of PLAFuzhou350025China

Objective:To evaluate the efficacy and safety of Cidan Capsule combined with adjuvant transarterial chemoembolization(TACE) in patients with a high risk of early recurrence after curative resection of hepatocellular carcinoma(HCC).Methods:A multicenter,randomized controlled trial was conducted in patients with high-risk recurrence factors after curative resection of HCC from 9 medical centers between July 2014 and July ***249 patients were randomly assigned to TACE with or without Cidan Capsule administration groups by stratified block in a 1:1 *** adjuvant TACE was given 4-5 weeks after hepatic resection in both ***,125 patients in the TACE plus Cidan group were administrated Cidan Capsule(0.27 g/capsule,5 capsules every time,4 times a day) for 6 months with a 24-month *** endpoints included diseasefree survival(DFS) and tumor recurrence rate(TRR).Secondary endpoint was overall survival(OS).Any drugrelated adverse events(AEs) were observed and ***:As the data cutoff on July 9th,2018,the median DFS was not reached in the TACE plus Cidan group and 234.0 days in the TACE group(hazard ratio,0.420,95%confidence interval,0.290-0.608;P<0.01).The 1-and 2-year TRR in the TACE plus Cidan and TACE groups were 31.5%,37.1%,and 60.8%,63.4%,respectively(P<0.01).Median OS was not reached in both ***1-and 2-year OS rates in TACE plus Cidan and TACE groups were 98.4%,98.4%,and 89.5%,87.9%,respectively(P<0.05).The most common grade 3-4 AEs included fatigue,abdominal pain,lumbar pain,and *** serious AE was reported in 1 patient in the TACE plus Cidan group,the death was due to retroperitoneal mass hemorrhage and hemorrhagic shock,and was not related to study ***:Cidan Capsule in combination with TACE can reduce the incidence of early recurrence in HCC patients at high-risk of recurrence after radical hepatectomy and may be an appropriate option in postoperative anti-recurrence treatment.(Reg

关键词： hepatocellular carcinoma hepatectomy recurrence survival transarterial chemoembolization Cidan Capsule

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2008年汶川地震与龙门山断裂带的深浅部变形及启示

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科学通报 2018年第19期63卷 1917-1933页

作者：陈棋福李乐中国科学院地质与地球物理研究所、中国科学院地球与行星物理重点实验室北京100029 中国科学院地球科学研究院北京100029 中周科学院大学地球与行星科学学院北京100049 中国地震局地震预测研究所北京100036

概述了2008年汶川8.0级地震后近10年有关龙门山断裂带的深浅部变形研究结果,通过较为系统的综合对比分析,归纳得出的基本共识为:龙门山断裂带的深部构造形态和速度结构均十分复杂,2008年汶川8.0级地震是由多次子事件构成的十分复杂破裂... 详细信息

概述了2008年汶川8.0级地震后近10年有关龙门山断裂带的深浅部变形研究结果,通过较为系统的综合对比分析,归纳得出的基本共识为:龙门山断裂带的深部构造形态和速度结构均十分复杂,2008年汶川8.0级地震是由多次子事件构成的十分复杂破裂过程,其主要滑动量在深浅部都有展布.综合分析认为:龙门山断裂带中北段的深浅滑动速率存在明显差异,孕震深处的滑动速率约为浅部的2~3倍,以重复地震分析给出的深部滑动速率估算的汶川地震复发间隔约为500~4500 a.针对探测程度十分有限的大陆内部断裂带,应充分发挥重复地震的原位探测优势,集成地震学、大地测量学和地质地貌学的各自优势进行深浅部构造变形的有效探测分析,对断裂闭锁段和深浅构造变形差异显著地区的强震危险性尤应重视.

关键词：汶川地震龙门山断裂带深部变形重复地震强震危险性复发间隔

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Pn wave geometrical spreading and attenuation in Northeast China and the Korean Peninsula constrained by observations from North Korean nuclear explosions

Pn wave geometrical spreading and attenuation in Northeast C...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Lian-Feng Zhao Xiao-Bi Xie Bao-Feng Tian qi-fu chen Tian-Yao Hao Zhen-Xing Yao Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Geophysics and Planetary Physics University of California Institute of Geophysics China Earthquake Administration

We investigate the geometric spreading and attenuation of seismic Pn waves in Northeast China and the Korean Peninsula. A high-quality broadband Pn wave data set generated by North Korean nuclear tests is used to constrain the parameters of a frequency-dependent log-quadratic geometric spreading function and a power law Pn Q model. The geometric spreading function and apparent Pn wave Q are obtained for Northeast China and the Korean Peninsula between 2.0 and 10.0 Hz. Using the two-station amplitude ratios of the Pn spectra and correcting them with the known spreading function, we remove the contributions of the source and crust from the apparent Pn Q and retrieve the P wave attenuation information along the pure upper mantle path. We then use both Pn amplitudes and amplitude ratios in a tomographic approach to obtain the upper mantle P wave attenuation in the studied area. The Pn wave spectra observed in China are compared with those recorded in Japan, and the result reveals that the high-frequency Pn signal across the oceanic path attenuated faster compared with those through the continental path.

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Prediction and stratification for the surgical adverse events after minimally invasive esophagectomy:A two-center retrospective study

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World Journal of Gastroenterology 2025年第3期31卷 50-61页

作者： qi-Hong Zhong Jiang-Shan Huang Fei-Long Guo Jing-Yu Wu Mao-Xiu Yuan Jia-fu Zhu Wen-Wei Lin Sui chen Zhen-Yang Zhang Jiang-Bo Lin Department of Thoracic Surgery Fujian Medical University Union HospitalFuzhou 350001Fujian ProvinceChina The Graduate School Fujian Medical UniversityFuzhou 350001Fujian ProvinceChina Department of Thoracic Surgery Affiliated Hospital of Jinggangshan UniversityJi’an 343000Jiangxi ProvinceChina

BACKGROUND Minimally invasive esophagectomy(MIE)is a widely accepted treatment for esophageal cancer,yet it is associated with a significant risk of surgical adverse events(SAEs),which can compromise patient recovery and long-term *** preoperative identification of high-risk patients is critical for improving *** To establish and validate a risk prediction and stratification model for the risk of SAEs in patients with *** This retrospective study included 747 patients who underwent MIE at two centers from January 2019 to February *** were separated into a train set(n=549)and a validation set(n=198).After screening by least absolute shrinkage and selection operator regression,multivariate logistic regression analyzed clinical and intraoperative variables to identify independent risk factors for SAEs.A risk stratification model was constructed and validated to predict the probability of *** SAEs occurred in 10.2%of patients in train set and 13.6%in the validation *** with SAE had significantly higher complication rate and a longer hospital stay after *** key independent risk factors identified included chronic obstructive pulmonary disease,a history of alcohol consumption,low forced expiratory volume in the first second,and low albumin *** stratification model has excellent prediction accuracy,with an area under the curve of 0.889 for the training set and an area under the curve of 0.793 for the validation *** The developed risk stratification model effectively predicts the risk of SAEs in patients undergoing MIE,facilitating targeted preoperative interventions and improving perioperative management.

关键词： Surgical adverse events Minimally invasive esophagectomy Esophageal cancer Stratification model Perioperative management

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Spatio-temporal model for soil characteristic of reclamation land

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中国有色金属学会会刊：英文版 2005年第S1期15卷 45-48页

作者： chen qiu-ji~(1, 2), HU Zhen-qi~1, fu Mei-chen~3, XIE Hong-quan~4, HAO Hai-fu~5 (1. China University of Mining and Technology(Beijing Campus), Beijing 100083, China 2. Henan Polytechnic University, Jiaozuo 454000, China 3. China University of Geosciences, Beijing 100083, China 4. Hebei Polytechnic University, Tangshan 063009, China 5. China Railway Shiqiju Group Corporation, Taiyuan 030600, China)

The development of spatio-temporal data model is introduced. According to the soil characteristic of reclamation land, we adopt the base state with amendments model of multi-layer raster to organize the spatio-temporal data, using the combined data structure on linear quadtree and linear octree to code. The advantage of this model is that it can easily obtain the information of certain layer and integratedly analyze the data with other methods. Then, the methods of obtain and analyses are introduced. The method can provide a tool for the research of the soil characteristic change and spatial distribution in reclamation land.

关键词： reclamation soil spatio-temporal data model linear quad-tree linear octree

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