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| 1 | Investigation and assessment on mountain tunnels and geotechnical damage after the Wenchuan earthquake显示文摘On May 12, 2008, a strong earthquake with a magnitude of 8.0 (Ms) struck Wenchuan town, in the eastern Sichuan area of west China. Following the earthquake on May 18, the Southwest Jiaotong University organized a damage survey team and dispatched it to the affected area for the investigation into the damage and collection of information and data. This paper outlines the findings of this investigation on the earthquake disaster to mountain tunnels and geotechnical engineering. The systematic investigation, involving geological conditions, design documents, construction and maintenance records of the tunnels, has been conducted and the degree of damage to investigated tunnels has been assessed according to the width and length of cracks, the stability of the slope above the tunnel, and the condition of the groundwater inrush. The results show that the major damage of the mountain tunnels was mainly concentrated in the tunnel portals due to widespread landslides and rockfalls, and the inner part of investigated tunnels suffered moderate damages mainly due to fault displacements. It is hoped that the information shared herein could enhance the outstanding of seismic behavior of mountain tunnels and improve seismic design and construction procedures. | WANG ZhengZheng GAO Bo JIANG YuanJun YUAN Song | 2009 | Science China(Technological Sciences)2009,52,2: | 84 |
| 2 | Simultaneous in-situ determination of U-Pb age and trace elements in zircon by LA-ICP-MS in 20 μm spot size显示文摘Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 206Pb/238U ages of 91500,GJ1 and TEMORA 1 are 1064.4±4.8 Ma(2σ ),603.2±2.4 Ma(2σ ) and 418.2±2.4 Ma(2σ ),respectively. The relative standard de-viations(RSDs) of 206Pb/238U ages(2σ ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three standard zircons agree with the recommended values within 2σ error. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma(2σ ) and the RSDs of 206Pb/238U ages(2σ ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan(2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements simultaneously by LA-ICP-MS in a small spot size of 20 μm. | LIU XiaoMing GAO Shan DIWU ChunRong YUAN HongLin HU ZhaoChu | 2007 | Chinese Science Bulletin2007,52,9: | 107 |
| 3 | The Tea Tree Genome Provides Insights into Tea Flavor and Independent Evolution of Caffeine Biosynthesis显示文摘茶是世界有巨大的经济、药用、文化的重要性的最旧、很流行的包含咖啡因的饮料。这里,我们在场第一个高质量的核苷酸序列充满重复(80.9%) ,栽培的茶树山茶 sinensis 的 3.02-Gb 染色体。我们证明茶树的一种非常地大的染色体尺寸从一些 LTR retrotransposon 家庭的慢、稳定、长期的扩大被结果。除了一个最近的整个染色体的复制事件,基因的系特定的扩大把新陈代谢的生合成与 flavonoid 联系了被发现,它提高 catechin 生产,萜烯酶激活,和应力公差,为茶风味和改编的重要特征。我们相对可可子和咖啡表明一个独立人士和茶咖啡因合成小径的快速的进化。在 25 山茶种类之中的比较研究表明那更高的表情大多数 flavonoid- 和咖啡因铺平 -- 然而并非 theanine 相关的基因贡献 catechins 和咖啡因的增加的生产并且因此提高处理茶的适用性和茶质量。这些新奇调查结果为进一步的 metabolomic 和典型生合成小径的功能的 genomic 精炼铺平道路并且将帮助开发将最后满足并且吸引世界范围的更多的茶喝酒者的茶风味的一个更多样化的集合。 | En-Hua Xia Hai-Bin Zhang Jun Sheng Kui Li Qun-Jie Zhang Changhoon Kim Yun Zhang Yuan Liu Ting Zhu Wei Li Hui Huang Yan Tong Hong Nan Cong Shi Chao Shi Jian-Jun Jiang Shu-Yan Mao Jun-Ying Jiao Dan Zhang Yuan Zhao You-Jie Zhao Li-Ping Zhang Yun-Long Liu Ben-Ying Liu Yue Yu Sheng-Fu Shao De-Jiang Ni Evan E. Eichler Li-Zhi Gao | 2017 | Molecular Plant2017,10,6: | 113 |
| 4 | 2019新型冠状病毒基因组特征和流行病学:病毒起源和受体结合的意义显示文摘研究者对来自9例新型冠状病毒肺炎住院患者的支气管肺泡灌洗液样本和培养的分离株进行了下一代测序。从这些个体中获得了严重急性呼吸综合征-冠状病毒2(severe acute respiratory syndrome-coronavirus 2,SARS-CoV-2)的完整和部分基因组序列。利用Sanger测序连接病毒重叠群以获得全长基因组,cDNA末端快速扩增确定终端区。对这些SARSCoV-2基因组和其他冠状病毒基因组进行了系统进化分析,以确定该病毒的进化史并有助于推断其可能的起源。 | 刘青(译) 刘莉(审校) Lu R Zhao X Li J Niu P Yang B Wu H Wang W Song H Huang B Zhu N Bi Y Ma X Zhan F Wang L Hu T Zhou H Hu Z Zhou W Zhao L Chen J Meng Y Wang J Lin Y Yuan J Xie Z Ma J Liu WJ Wang D Xu W Holmes EC Gao GF Wu G Chen W Shi W Tan W | 2020 | 中华高血压杂志2020,28,3: | 516 |
| 5 | Determination of U-Pb age and rare earth element concentrations of zircons from Cenozoic intrusions in northeastern China by laser ablation ICP-MS显示文摘Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern. | YUAN Honglin WU Fuyuan GAO Shan LIU Xiaoming XU Ping SUN Deyou | 2003 | Chinese Science Bulletin2003,48,22: | 252 |
| 6 | Enhanced efficiency of generating induced pluripotent stem (iPS) cells from human somatic cells by a combination of six transcription factors显示文摘 | Jing Liao Zhao Wu Ying Wang Lu Cheng Chun Cui Yuan Gao Taotao Chen Lingjun Rao Siye Chen Nannan Jia Huiming Dai Shunmei Xin Jiuhong Kang Gang Pei Lei Xiao | 2008 | Cell Research2008,18,5: | 61 |
| 7 | Immune mechanisms of Concanavalin A model of autoimmune hepatitis显示文摘As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatments of AIH are immunosuppressant application and liver transplantation.It is considered that lack of good animal AIH models is the main reason for the shortage of a simple and efficient cure.The Concanavalin A (Con A) model is a typical and well established model for investigating T-cell and macrophage dependent liver injury in mice,which closely mimics the pathogenesis mechanisms and pathological changes of patients,and is regarded as the best experimental model for AIH research so far.In this paper we eluci-dated the pathogenic mechanisms of AIH and the evolution of relative animal models.We go on to further focus on Con A-induced liver injury from the point of immunological mechanisms and the change of cytokine levels.Finally,we manifested the clinical significance of the AIH animal models and the challenges they would meet during their future development. | Hai-Xia Wang Man Liu Shun-Yan Weng Jing-Jing Li Chao Xie Hong-Lin He Wen Guan Yun-Sheng Yuan Jin Gao | 2012 | World Journal of Gastroenterology2012,18,2: | 52 |
| 8 | Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017显示文摘Although much attention has been paid to investigating and controlling air pollution in China,the trends of air-pollutant concentrations on a national scale have remained unclear.Here,we quantitatively investigated the variation of air pollutants in China using long-term comprehensive data sets from 2013 to 2017,during which Chinese government made major efforts to reduce anthropogenic emission in polluted regions.Our results show a significant decreasing trend in the PM2.5 concentration in heavily polluted regions of eastern China,with an annual decrease of〜7%compared with measurements in 2013.The measured decreased concentrations of SO2>NO2 and CO(a proxy for anthropogenic volatile organic compounds)could explain a large fraction of the decreased PM2.5 concentrations in different regions.As a consequence;the heavily polluted days decreased significantly in corresponding regions.Concentrations of organic aerosol;nitrate;sulfate,ammonium and chloride measured in urban Beijing revealed a remarkable reduction from 2013 to 2017;connecting the decreases in aerosol precursors with corresponding chemical components closely.However;surface-ozone concentrations showed increasing trends in most urban stations from 2013 to 2017;which indicates stronger photochemical pollution.The boundary-layer height in capital c让ies of eastern China showed no significant trends over the Beijing-Tianjin-Hebei,Yangtze River Delta and Pearl River Delta regions from 2013 to 2017;which confirmed the reduction in anthropogenic emissions.Our results demonstrated that the Chinese government was successful in the reduction of particulate matter in urban areas from 2013 to 2017,although the ozone concentration has increased significantly;suggesting a more complex mechanism of improving Chinese air quality in the future. | Yonghong Wang Wenkang Gao Shuai Wang Tao Song Zhengyu Gong Dongsheng Ji Lili Wang Zirui Liu Guiqian Tang Yanfeng Huo Shili Tian Jiayun Li Mingge Li Yuan Yang Biwu Chu Tuukka Petaja Veli-Matti Kerminen Hong He Jiming Hao Markku Kulmala Yuesi Wang Yuanhang Zhang | 2020 | National Science Review2020,7,8: | 51 |
| 9 | Apoptosis,proliferation and p53 gene expression of H.pylori associated gastric epithelial lesions显示文摘AIM: To study the relationship between Helicobacter pylori (H. Pylori) and gastric carcinoma and its possible pathogenesis by H. Pylori.METHODS: DNEL technique and immunohistochemical technique were used to study the state of apoptosis,proliferation and p53 gene expression. A total of 100 gastric mucosal biopsy specimens, including 20 normal mucosa, 30H. Pylori-negative and 30 H. Pylorf-positive gastric precancerous lesions along with 20 gastric carcinomas were studied.RESULTS: There were several apoptotic cells in the superficial epithelium and a few proliferative cells within the neck of gastric glands, and no p53 protein expression in normal mucosa. In gastric carcinoma, there were few apoptotic cells, while there were a large number of proliferative cells, and expression of p53 protein significantly was increased. In the phase of metaplasia, the apoptotic index (Al, 4.36% ± 1.95%), proliferative index (PI, 19.11% ± 6.79%) and positivity of p53 expression (46.7%) in H. Pylori-positive group were higher than those in normal mucosa (P< 0.01). Al in H. Pylori-positive group was higher than that in H. Pylori-negative group (3.81% ±1.76%), PI in H. Pylori-positive group was higher than that in H. Pylori-negative group (12.25% ±5.63%, P<0.01 ). In the phase of dysplasia, Al (2.31% ± 1.10%) in H. Pylori-positive group was lower (3.05% ± 1.29%) than that in H. Pylori-negative group, but PI (33.89% ± 11.65%)wassignificantly higher(22.09± 8018%, P< 0.01). In phases of metaplasia, dysplasia and gastric cancer in the H. Pylori-positive group, Als had an evidently graduall decreasing trend (P < 0.01 ), while Pis had an evidently gradual increasing trend (P< 0.05 or P< 0.01), and there was also a trend of gradual increase in the expression of p53 gene.CONCLUSION: In the course of the formation of gastric carcinoma, proliferation of gastric mucosa can be greatly increased by H. Pylori, and H. Pylori can induce apoptosis in the phase of metaplasia but in the phase of dysplasia H.pylori can inhibit cellular apoptosis. And H. Pylori infection can strengthen the expression of mutated p53 gene. | Zhong Zhang~1 Yuan Yuan Hua Gao Ming Dong Lan Wang Yue-Hua Gong 1 Department of Pathology,Shenyang Medical College,Shenyang 110031 Liaoning Province,China | 2001 | World Journal of Gastroenterology2001,7,6: | 46 |
| 10 | Shear-wave splitting beneath Yunnan area of Southwest China显示文摘Systematic analyses of seismic data recorded by the Yunnan regional seismograph network reveal significant crustal and upper mantle anisotropy.Splitting of the S phase of local earthquakes and teleseismic SKS,PKS,and SKKS phases indicates time-delays from 1.60 ms/km to 2.30 ms/km in the crust,and from 0.55 s to 1.65 s in the upper mantle which corresponds to an anisotropic layer with a thickness about between 55-165 km.The polarization orientations of fast shear waves in the crust are complicated with a predominantly north-south direction,and the mantle anisotropy has a nearly west-east direction.Our results show different deformation styles and mechanisms exist between the crust and upper mantle. | Yutao Shi Yuan Gao Youjin Su Qiong Wang | 2012 | Earthquake Science2012,25,1: | 46 |
| 11 | SlMYB75,an MYB-type transcription factor,promotes anthocyanin accumulation and enhances volatile aroma production in tomato fruits显示文摘Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality. | Wei Jian Haohao Cao Shu Yuan Yudong Liu Juanfang Lu Wang Lu Ning Li Jianhui Wang Jian Zou Ning Tang Chan Xu Yulin Cheng Yanqiang Gao Wanpeng Xi Mondher Bouzayen Zhengguo Li | 2019 | Horticulture Research2019,6,1: | 39 |
| 12 | Crust-mantle coupling in North China:Preliminary analysis from seismic anisotropy显示文摘Data from the CASN(Capital Area Seismograph Network),NSNC(National Seismograph Network of China),and IRIS(Incorporated Research Institutions for Seismology) are compared with data from a temporary North China Seismic Array to obtain the background orientation of the horizontal crustal principal compressive stress at NE 95.1°±15.4° in North China.Data are corrected for disturbances of faults and irregular tectonics,and are used to constrain the fast SKS polarization at NE 110.2°±15.8° in North China.Individual station analyses suggests that there is consistently more than 10° difference between the polarizations of fast shear-wave in the crust and those of fast SKS phases.Azimuthally anisotropic phase velocities of Rayleigh waves at different periods also indicate an orientation change for fast velocity with depth.It suggests the crust-mantle coupling in North China follows neither the simple decoupling model nor the strong coupling model.Instead,it is possibly some inhomogeneous combination of two models or some gradual-change model of physical characteristics.This study shows that anisotropy in the crust and mantle could be multiply characterized more correctly and crust-mantle coupling could be analyzed further,if increasing near-field shear-wave splitting data that indicate crustal anisotropy,combined with the azimuthal anisotropy of Rayleigh waves,besides the result of SKS splitting travelling through lithosphere and surface GPS measurements. | GAO Yuan WU Jing YI GuiXi SHI YuTao | 2010 | Chinese Science Bulletin2010,55,31: | 34 |
| 13 | A novel m6A reader Prrc2a controls oligodendroglial specification and myelination显示文摘While N6-methyladenosine (m6A), the most abundant internal modification in eukaryotic mRNA, is linked to cell differentiation and tissue development, the biological significance of m6A modification in mammalian glial development remains unknown. Here, we identify a novel m6A reader, Prrc2a (Proline rich coiled-coil 2A), which controls oligodendrocyte specification and myelination. Nestin-Cre-mediated knockout of Prrc2a induces significant hypomyelination, decreased lifespan, as well as locomotive and cognitive defects in a mouse model. Further analyses reveal that Prrc2a is involved in oligodendrocyte progenitor cells (OPCs) proliferation and oligodendrocyte fate determination. Accordingly, oligodendroglial-lineage specific deletion of Prrc2a causes a similar phenotype of Nestin-Cre-mediated deletion. Combining transcriptome-wide RNA-seq, m6A-RIP-seq and Prrc2a RIP-seq analysis, we find that Olig2 is a critical downstream target gene of Prrc2a in oligodendrocyte development. Furthermore, Prrc2a stabilizes Olig2 mRNA through binding to a consensus GGACU motif in the Olig2 CDS (coding sequence) in an m6A-dependent manner. Interestingly, we also find that the m6A demethylase, Fto, erases the m6A modification of Olig2 mRNA and promotes its degradation. Together, our results indicate that Prrc2a plays an important role in oligodendrocyte specification through functioning as a novel m6A reader. These findings suggest a new avenue for the development of therapeutic strategies for hypomyelination-related neurological diseases. | Rong Wu Ang Li Baofa Sun Jian-Guang Sun Jinhua Zhang Ting Zhang Yusheng Chen Yujie Xiao Yuhao Gao Qingyang Zhang Jun Ma Xin Yang Yajin Liao Wei-Yi Lai Xiaolong Qi Shukun Wang Yousheng Shu Hai-Lin Wang Fengchao Wang Yun-Gui Yang Zengqiang Yuan | 2019 | Cell Research2019,29,1: | 32 |
| 14 | Summary of Report on Cardiovascular Diseases in China,2012显示文摘The prevalence of cardiovascular diseases(CVDs)is associated with the socioeconomic prosperity,lifestyle changes,accelerated process of ageing and urbanization.The prevalence of CVDs is continuously increasing in China and will remain an upward trend in the next 10 years.CVDs are the leading cause of death for Chinese in both urban area and rural area. | WANG Wen HU Sheng Shou KONG Ling Zhi GAO Run Lin ZHU Man Lu WANG Yong Jun WU Zhao Su CHEN Wei Wei YANG Jin Gang MALi Yuan LIU Ming Bo For the editorial board | 2014 | Biomedical and Environmental Sciences2014,27,7: | 31 |
| 15 | Efficacy and Safety Investigation of Kuntai Capsule for the Add-back Therapy of Gonadotropin Releasing Hormone Agonist Administration to Endometriosis Patients: A Randomized,Double-blind, Blank-and Tibolone-controlled Study显示文摘 | Ji-Ming Chen Hong-Yan Gao Yi Ding Xia Yuan Qing Wang Qin Li Guo-Hua Jiang | 2015 | Chinese Medical Journal2015,,4: | 31 |
| 16 | Improved survival of porcine acute liver failure by a bioartificial liver device implanted with induced human functional hepatocytes显示文摘 | Xiao-Lei Shi Yimeng Gao YupengYan HuchengMa Lulu Sun Pengyu Huang Xuan Ni Ludi Zhang Xin Zhao Haozhen Ren Dan Hu Yan Zhou Feng Tian Yuan Ji Xin Cheng Guoyu Pan Yi-Tao Ding LijianHui | 2016 | Cell Research2016,26,2: | 31 |
| 17 | Effects of Traditional Chinese Medicine Shensong Yangxin Capsules on Heart Rhythm and Function in Congestive Heart Failure Patients with Frequent Ventricular Premature Complexes:A Randomized, Double-blind, Multicenter Clinical Trial显示文摘 | Xi Wang Dan HU Song Dang He Huang Cong-Xin Huang Ming-Jie Yuan Yan-Hong Tang Qing-Shan Zheng Fang Yin Shu Zhang Bo-Li Zhang Run-Lin Gao | 2017 | Chinese Medical Journal2017,,14: | 33 |
| 18 | New incompatible pair of TCM:Epimedii Folium combined with Psoraleae Fructus induces idiosyncratic hepatotoxicity under immunological stress conditions显示文摘Epimedii Folium(EF)combined with Psoraleae Fructus(PF)is a common modern preparation,but liver injury caused by Chinese patent medicine preparations containing EF and PF has been frequently reported in recent years.Zhuangguguanjiewan pills(ZGW),which contain EF and PF,could induce immune idiosyncratic liver injury according to clinical case reports and a nonhepatotoxic dose of lipopolysaccharide(LPS)model.This present study evaluated the liver injury induced by EF or PF alone or in combination and investigated the related mechanism by using the LPS model.Liver function indexes and pathological results showed that either EF or PF alone or in combination led to liver injury in normal rats;however,EF or PF alone could lead to liver injury in LPS-treated rats.Moreover,EF combined with PF could induce a greater degree of injury than that caused by EF or PF alone in LPS-treated rats.Furthermore,EF or PF alone or in combination enhanced the LPS-stimulated inflammatory cytokine production,implying that IL-1β,which is processed and released by activating the NLRP3 inflammasome,is a specific indicator of EF-induced immune idiosyncratic hepatotoxicity.Thus,EF may induce liver injury through enhancing the LPS-mediated proinflammatory cytokine production and activating the NLRP3 inflammasome.In addition,the metabolomics analysis results showed that PF affected more metabolites in glycerophospholipid and sphingolipid metabolic pathways compared with EF in LPS model,suggesting that PF increased the responsiveness of the liver to LPS or other inflammatory mediators via modulation of multiple metabolic pathways.Therefore,EF and PF combination indicates traditional Chinese medicine incompatibility,considering that it induces idiosyncratic hepatotoxicity under immunological stress conditions. | Yuan Gao Zhilei Wang Jinfa Tang Xiaoyi Liu Wei Shi Nan Qin Xiaoyan Wang Yu Pang Ruisheng Li Yaming Zhang Jiabo Wang Ming Niu Zhaofang Bai Xiaohe Xiao | 2020 | Frontiers of Medicine2020,14,1: | 32 |
| 19 | Compressive stress field in the crust deduced from shear-wave anisotropy: an example in capital area ofChina显示文摘The rocks in the crust are pervaded by stress-aligned fluid-saturated microcracks, and the complex fault tectonics and stress control the configuration of the microcracks, however shear-wave splitting could indicate this kind of characteristics. In this paper, Capital Area Seismograph Network (CASN), the widest scope and highest density of regional seismograph network presently in China, is adopted to deduce the principal compressive stress field distribution pattern from polarizations of fast shear- waves, based on shear-wave splitting analysis. The principal compressive stress in capital area of China is at NE85.7°± 41.0° in this study. Compared with the results of principal compressive stress field in North China obtained from other methods, the results in this study are reliable in the principal com- pressive stress field distribution in capital area. The results show that it is an effective way, although it is the first time to directly obtain crustal stress field from seismic anisotropy. It is effectively applied to the zones with dense seismograph stations. | GAO Yuan WU Jing | 2008 | Chinese Science Bulletin2008,53,18: | 29 |
| 20 | Rayleigh wave phase velocity tomography and strong earthquake activity on the southeastern front of the Tibetan Plateau显示文摘To investigate the relationship between velocity structure and earthquake activity on the southeastern front of the Tibetan Plateau, we make use of continuous observations of seismic ambient noise data obtained at 55 broadband stations from the regional Yunnan Seismic Network. These data are used to compute Rayleigh wave Green's Functions by cross-correlating between two stations, extracting phase velocity dispersion curves, and finally inverting to image Rayleigh wave phase velocity with periods between 5 and 34 s by ambient noise tomography. The results show significant lateral variations in crustal and uppermost mantle structures in the studied region. Phase velocity anomalies at short periods(5–12 s) are closely related to regional tectonic features such as sediment thickness and the depth of the crystalline basement. The Sichuan-Yunnan rhombic block, enclosed by the Honghe, Xiaojiang and Jianchuan faults, emerges as a large range of low-velocity anomalies at periods of 16–26 s, that inverts to high-velocity anomalies at periods of 30–34 s. The phase velocity variation in the vicinity of the Sichuan-Yunnan rhombic block suggests that the low-velocity anomaly area in the middle-lower crust may correspond to lower crustal channelized flow of the Tibetan Plateau. The spatial distribution of strong earthquakes since 1970 reveals that the Yunnan region is inhomogeneous and shows prominent characteristics of block motion. However, earthquakes mostly occur in the upper crust, with the exception of the middle-Yunnan block where earthquakes occur at the interface zone between high and low velocity as well as in the low-velocity zones, with magnitudes being generally less than 7. There are few earthquakes of magnitude 5 at the depths of 15–30 km, where gather earthquakes of magnitude 7 or higher ones which mainly occur in the interface zone between high and low velocities with others extending to the high-velocity abnormal zone. | WANG Qiong GAO Yuan | 2014 | Science China Earth Sciences2014,57,10: | 30 |