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The North-South Seismic Belt： Vertical Deformation Velocity Gradient Research

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Earthquake Research in China 2017年第2期31卷 169-178页

作者： Liu Liwei Ji Lingyun Zhao Qiang The Second Monitoring and Application Center CEA Xi'an 710054 China

The vertical deformation gradient can reflect the rate of vertical change in unit distance,and the vertical deformation velocity gradient can reflect the strength of the earth's crust tectonic activities. In this paper,using long period leveling data combined with GPS data,the vertical deformation gradient values are calculated. Leveling data and GPS data are two different means of monitoring deformation,but the result is approximately the same vertical deformation gradient. The results show that the spatial distribution of the vertical deformation velocity gradient and tectonic distribution has an obvious correlation. The most significant gradient anomalies along the North-South Seismic Belt are Xianshuihe fault, Longmenshan fault and Xiaojiang-Zemuhe fault, while the second gradient anomalies in the northeastern Qinghai-Tibetan plateau are Zhuanglanghe fault and Lenglongling fault. The Menyuan M_S6. 4 earthquake in 2016 occurred in this abnormal area. However,according to the vertical deformation high gradient area distribution,there is also the possibility of an earthquake occurrence in the Tianzhu and Jingtai *** area of convergence of three major fault zones is the strongest tectonically active region of the North-South Seismic Belt.

关键词： Gradient North-South Seismic Belt Vertical deformation Strong Earthquake activty

The focal depths of the 2008 Panzhihua earthquake sequence and the stress field in the source region

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Science China Earth Sciences 2020年第3期63卷 439-451页

作者： Yan LUO Li ZHAO Jianhui TIAN Key Laboratory of Earthquake Prediction Institute of Earthquake ForecastingCEABeijing 100036China School of Earth and Space Sciences Peking UniversityBeijing 100871China

Focal depths of the 2008 Ms6.1 Panzhihua earthquake sequence and tectonic stress field in the source area are *** depths of 24 earthquakes in Panzhihua earthquake sequence with a magnitude M≥3.0 were determined using the seismic depth phase sPL;additionally,the focal depths of 232 earthquakes were measured by fitting the threecomponent waveforms of the P and S *** source depth of the main shock is^12 *** majority of the aftershocks with magnitude M≥3.0 occurred in the brittle upper crust at the depths range of 12-18 ***,the Source mechanisms of the 232events around the Panzhihua earthquake source area were determined,and the results show that the earthquakes have predominantly strike-slip mechanisms in the Dianzhong Block,but display complexity of the focal mechanisms outside and near the boundary of the Dianzhong *** 232 earthquake mechanisms from this study are combined with the solutions from the Global Centroid Moment Tensor (GCMT) catalog to derive 2D stress *** inversion results show that the Dianzhong block is predominantly under a strike slip faulting regime and the direction of the maximum principal compressionσ1 is northwestsoutheast (NW-SE)-*** distribution is coincide with GPS velocity ***,orientations of principal stress axes as well as the faulting types change outside and near the Dianzhong *** results show that the tectonic stress field in the study area is predominantly controlled by the southeast (SE)-trending horizontal movement and clockwise rotation of the Dianzhong block as a result of the eastward movement of eastern Tibetan meeting the old and rigid South China block (SCB).The Panzhihua earthquake ruptured at^12 km depth where the tectonic stress regime is under the SE-direction horizontal compression and the NE-direction horizontal extension.

关键词： Panzhihua earthquake sequence Depth phase Focal mechanism solution Tectonic stress field

Seismic damage to structures in the Ms6.5 Ludian earthquake

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Earthquake Engineering and Engineering Vibration 2016年第1期15卷 173-186页

作者： Chen Hao Xie Quancai Dai Boyang Zhang Haoyu Chen Hongfu Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering Mechanics CEA Harbin 150080 China Earthquake Administration of Yunnan Province Kunming 650224 China

On 3 August 2014, the Ludian earthquake struck northwest Yunnan Province with a surface wave magnitude of 6.5. This moderate earthquake unexpectedly caused high fatalities and great economic loss. Four strong motion stations were located in the areas with intensity V, VI, VII and IX, near the epicentre. The characteristics of the ground motion are discussed herein, including 1） ground motion was strong at a period of less than 1.4 s, which covered the natural vibration period of a large number of structures; and 2） the release energy was concentrated geographically. Based on materials collected during emergency building inspections, the damage patterns of adobe, masonry, timber frame and reinforced concrete （RC） frame structures in areas with different intensities are summarised. Earthquake damage matrices of local buildings are also given for fragility evaluation and earthquake damage prediction. It is found that the collapse ratios of RC frame and confined masonry structures based on the new design code are significantly lower than non-seismic buildings. However, the RC frame structures still failed to achieve the ＇strong column, weak beam＇ design target. Traditional timber frame structures with a light infill wall showed good aseismic performance.

关键词： Ludian earthquake investigations of seismic damage masonry structure RC frame timber flame adobehouse

Research on the Source Parameters and Correlation Coefficients of Focal Mechanisms for the Yingjiang Earthquake Sequences in 2008

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Earthquake Research in China 2015年第1期29卷 68-83页

作者： Deng Fei Liu Jie Institute of Earthquake Science CEA China Earthquake Networks Center

The source parameters of the Yingjiang earthquake sequences in 2008 are obtained by applying spectral analysis and Brunes source model,based on the digital waveform data recorded by the Yunnan Digital Seismic *** correlation coefficients are calculated using the low-frequency spectral amplitudes of 2 events recorded by a same station,then,events with similar focal mechanism are grouped using the clustering analysis *** to the obtained focal mechanisms,it is found that there are good correlations with the azimuth of P axes in each clustering group,and the larger the correlation coefficient,the closer the azimuths of P *** divide the Yingjiang area into 3 regions to analyze the stress level and stress direction by combining the source parameters and the mean focal mechanism of each *** results show:The change and transformation of the focal mechanism types at different stages can represent the temporal characteristics of the regional stress *** the earthquake focal mechanism types are concentrated in a time period and switch to the direction of regional stress field,it may be a sign of strong *** is some relationship between the stress drop and the type of focal *** earthquakes with stress fields revealed by focal mechanism types closer to the regional tectonic stress field will have higher stress drop,while those with the focal mechanism-revealed stress fields differing a lot from the regional tectonic stress field will generally have a lower stress drop.

关键词： Stress drop Correlation of focal mechanisms Clustering group Yingjiangearthquake sequences in 2008

Characterization of the Crustal Thickness and Poisson's Ratio of the Binchuan Region

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Earthquake Research in China 2017年第1期31卷 79-89页

作者： Deng Jiamei Jin Mingpei Chen Jia Gao Qiong Zhang Huaying Wang Jun Ye Beng Office of the Western Yunnan Earthquake Prediction Study Area CEA

This paper presents the changes of crust thickness and Poisson＇s ratios distribution in the Binchuan region, where the first air-gun transmitting station and it＇s a small dense array were deployed. From September 2011 to January 2014, more than 239 teleseismic events of M≥ 6.0 were recorded in 16 stations in the Binchuan region. Their P-wave receiver functions were analyzed respectively. The high spatial resolution result shows that the average crust thickness of Binchuan region is 45.3km, it follows the rule of ＂deeper in the north and east part, shallower in the south and west part. ＂ The deepest region is in Xiaoyindian Station; the crust thickness is 47.9km; the shallowest region is in Paiying Station, it has the thickness of 42. lkm. It shows that the deeper Moho surface nearby the Chenghai fault and shallower nearby the Honghe fault; the isoline distribution of thickness changes greatly nearby the Chenghai fault and slowly nearby the Honghe fault. From the distribution of Poisson＇s ratios, it is unevenly in the study area with a great difference from the north part to the south part, which shows a characteristic of ＂lower in the north, higher in the south＂. The Poisson＇s ratio nearby the Honghe fault is medium too high （ 0. 26 ≤ σ≤0. 29 ） ; lower nearby the Chenghai fault （ ≤0. 26）. This paper concludes the possible reason of different characteristic between Poisson＇s ratio and crust thickness is thicker in the upper crust in the Binchuan region.

关键词： Crustal thickness Poisson's ratio Receiver function The Binchuan region

Rapid laser synthesis of surfactantless tantalum-based nanomaterials as bifunctional catalysts for direct peroxide–peroxide fuel cells

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SmartMat 2023年第6期4卷 84-97页

作者： Xiaoyong Mo Brigitte Bouchet Fabre Nathalie Herlin-Boime Edmund C.M.Tse HKU-CAS Joint Laboratory on New Materials Department of ChemistryUniversity of Hong KongHong Kong SARChina NIMBE CEACNRSCEA SaclayUniversitéParis-SaclayGif-sur-YvetteFrance HKU Zhejiang Institute of Research and Innovation HangzhouChina

Efficient and durable electrocatalysts are instrumental in enabling next-generation fuel cell *** present,expensive precious metals are used as state-of-the-art *** this report,cost-effective nanosized tantalum-based alternatives are synthesized for the first time via a green and scalable laser pyrolysis method as bifunctional catalysts for direct peroxide–peroxide fuel *** rapid laser pyrolysis strategy allows for the production of nanoparticles at a laboratory scale of grams per hour,compatible with a detailed exploration of the functional properties of as-synthesized *** varying the precursor ratio between ammonia and tantalum ethanolate,five tantalum-based nanomaterials(TaNOC)are prepared with crystalline phases of Ta_(2)O_(5),Ta_(4)N_(5),Ta_(3)N_(5),and TaN in tunable *** studies in neutral and alkaline conditions demonstrate that Ta_(4)N_(5) is the active component for both H_(2)O_(2) oxidation and *** isotope effect studies show that protons are involved at or before the rate-determining ***-term stability studies indicate that Ta_(3)N_(5) grants surfactant-free TaNOC-enhanced longevity during electrocatalytic *** together,bifunctional TaNOC can act as active and robust electrocatalysts for H_(2)O_(2) reduction and *** pyrolysis is envisioned to produce refractory metal nanomaterials with boosted corrosion resistance for energy catalysis.

关键词： bifunctional catalysis laser pyrolysis peroxide fuel cells tantalum nanomaterials

A STUDY ON RELATION BETWEEN CONTINUOUS RAPID DEFORMATION AND EARTHQUAKLES

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大地测量与地球动力学 2003年第B12期23卷 79-82页

作者： Niu Anfu, Zhang Jing, Gao Fuwang, Ji Ping and Yan Xudong (Center for Analysis and Prediction, cea, Beijing 100036, China) Center for Analysis and Prediction CEA Beijing 100036 China

Continuous Rapid Deformation (CRD) may be an important precursor before some strong earthquakes with magnitude greater than \%M\%s5.0. This paper shows some characteristics of CRD, and proposes a method for identifying precursory CRD that is closely related to the process of earthquake preparation. From the deformation data in Yunnan Sichan provinces, we obtained the tilt and strain thresholds of 4.5ms/d and 5 ×10 -7 /d, respectively. Compared the tilt CRD in this region before 9 earthquakes (short term fore shocks and after shocks not included) with magnitude greater than 5.8 in the period from January of 1990 to May of 2001, we found that 8 earthquakes occurred within 5 months after the CRD with a duration of more than 20 days and a tilt velocity of more than 4.5ms/d without false prediction, but with one failure in earthquake prediction. For the strain CRD, 5 earthquakes occurred after the CRD; there was no false prediction, but 4 earthquakes unpredicted. We have tried to increase the thresholds, but found either the failure ratio or the rate of false prediction increased, while the success rate not obvious increased.

关键词：连续急速变形 CKD 地震预报变形与地震的关系 K型斜坡地壳形变

High-speed silicon photonic electro-optic Kerr modulation

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Photonics Research 2024年第1期12卷 51-60页

作者： JONATHAN PELTIER WEIWEI ZHANG LEOPOLD VIROT CHRISTIAN LAFFORGUE LUCAS DENIEL DELPHINE MARRIS-MORINI GUY AUBIN FARAH AMAR DENH TRAN XINGZHAO YAN CALLUM G.LITTLEJOHNS CARLOS ALONSO-RAMOS KE LI DAVID J.THOMSON GRAHAM REED LAURENT VIVIEN University Paris-Saclay CNRSCentre for Nanoscience and Nanotechnology(C2N)Palaiseau 91120France University Grenoble Alpes CEALETIGrenoble 38000France Optoelectronics Research Centre Zepler Institute for Photonics and NanoelectronicsFaculty of Engineering and Physical SciencesUniversity of SouthamptonSouthampton SO171BJUK

Silicon-based electro-optic modulators contribute to easing the integration of high-speed and low-power consumption circuits for classical optical communications and data *** the plasma dispersion modulation,an alternative solution in silicon is to exploit the DC Kerr effect,which generates an equivalent linear electro-optical effect enabled by applying a large DC electric *** some theoretical and experimental studies have shown its existence in silicon,limited contributions relative to plasma dispersion have been achieved in high-speed modulation so *** paper presents high-speed optical modulation based on the DC Kerr effect in silicon PIN *** contributions of both plasma dispersion and Kerr effects have been analyzed in different waveguide configurations,and we demonstrated that the Kerr induced modulation is dominant when a high external DC electric field is applied in PIN ***-speed optical modulation response is analyzed,and eye diagrams up to 80 Gbit/s in NRZ format are obtained under a *** of 30 *** work paves the way to exploit the Kerr effect to generate high-speed Pockels-like optical modulation.

关键词： waveguide dispersion effect

Local measurement for structural health monitoring

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Earthquake Engineering and Engineering Vibration 2005年第1期4卷 165-172页

作者：祁贵仲郭迅齐霄斋董伟民 P.Chang InfraTech Inc.SilverSpringMarylandUSA InstututeofEngineeringMechanics CEAHarbinChina RiskManagementSolution SanFranciscoCaliforniaUSA DepartmentofCivilEngineering UniversityofMaryland／CollegeParkUSA

Localized nature of damage in structures requires local measurements for structural health monitoring. The local measurement means to measure the local, usually higher modes of the vibration in a structure. Three fundamental issues about the local measurement for structural health monitoring including (1) the necessity of making local measurement, (2) the difficulty of making local measurement and (3) how to make local measurement are addressed in this paper. The results from both the analysis and the tests show that the local measurement can successfully monitor the structural health status as long as the local modes are excited. Unfortunately, the results also illustrate that it is difficult to excite local modes in a structure. Therefore, in order to carry structural health monitoring into effect, we must (1) ensure that the local modes are excited, and (2) deploy enough sensors in a structure so that the local modes can be monitored.

关键词： structure health monitoring local measurement local modes higher modes local modes excitation sensors structural vibration