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基于地震孕育过程追踪的地震预测方法

地震科学进展 2025年第2期55卷 63-76页

作者：陈学忠李艳娥陈丽娟中国地震局地球物理研究所北京100081 重庆市地震局重庆401147

准确的地震预测是实现有效减轻地震灾害的途径之一。目前地震预测仍处于经验预测阶段,其准确度远远不能满足有效减轻地震灾害的需求。地震预测的发展趋势在于从经验预测向物理预测过渡,这个过渡的关键在于要首先实现对地震孕育过程更加... 详细信息

准确的地震预测是实现有效减轻地震灾害的途径之一。目前地震预测仍处于经验预测阶段,其准确度远远不能满足有效减轻地震灾害的需求。地震预测的发展趋势在于从经验预测向物理预测过渡,这个过渡的关键在于要首先实现对地震孕育过程更加深入的认识、描述和追踪。根据岩石力学实验结果,岩石破坏前主要经历了应力上升过程和其后的亚失稳阶段。我们分析了天然地震的孕育过程。分析时将视应力和b值进行结合,以获得地壳介质的应力变化信息,利用地震活动与地球自转之间的相关性(用p值描述)来获取地壳介质的临界状态或亚失稳阶段的信息,从而实现对地震孕育过程的描述。本文在对天然强震孕育过程进行震例研究的基础上,提出了基于地震孕育过程追踪的地震预测思路和方法,给出了中-短期地震危险区判定依据,以期对实际地震预测工作有所裨益。

关键词：地震孕育过程地震预测中-短期地震危险区视应力 b值 p值

川滇地区地震活动与地球自转速率变化之间的关系

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地震 2019年第1期39卷 126-135页

作者：陈学忠李艳娥中国地震局地球物理研究所北京100081

利用川滇地区1962—2016年间发生的MS≥6.0地震资料,在去除余震的情况下,分析了其发生与地球自转速率变化极值点之间的关系。得到以下结果:川滇地区MS≥6.0地震的发生与地球自转速率变化极值点具有显著关系,对于不同震级范围的地震,其... 详细信息

利用川滇地区1962—2016年间发生的MS≥6.0地震资料,在去除余震的情况下,分析了其发生与地球自转速率变化极值点之间的关系。得到以下结果:川滇地区MS≥6.0地震的发生与地球自转速率变化极值点具有显著关系,对于不同震级范围的地震,其与不同周期的地球自转速率变化有关。对于MS≥7.0的地震,有90%发生在地球自转速率季节性变化极值点前14天至后37天时间段内;对于6.0≤MS≤6.4的地震,有80%发生在地球自转速率短周期变化极值点前68小时至后30小时的时间段内;对于6.5≤MS≤6.9的地震,有87.5%发生在地球自转速率短周期变化极值点前36小时至后64小时的时间段内。地震发生在特定时间段的显著性检验结果表明,川滇地区MS≥6.0地震与地球自转速率变化极值点的关系都可以在α=0.05的显著性水平下通过显著性检验。这个结果表明,在地球自转速率发生转折的期间容易触发地震,对川滇地区地震发生时间预测具有参考意义。

关键词：地震活动地球自转速率变化极值点川滇地区

Manufacture the conducting polymer with light

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Science China Chemistry 2025年第1期68卷 8-9页

作者： yang li Tianyu li yan Ji Baoguang liu College of electronic and Optical engineering&College of Flexible electronics(Future Technology) Nanjing University of Posts&TelecommunicationsNanjing 210023China

Poly(3,4-ethylenedioxythiophene)(PeDOT),heralded as the“king”of conducting polymers,is esteemed in bioelectronics for its mixed electronic and ionic conductivity,mechanical properties compatible with biological tissues,tunable healing ability and stability in diverse environments^([1]).Based on additive manufacturing of three-dimensional structures,PeDOT realizes the implementation in the efficient production of flexible bioelectronics,the construction of intricate electrode-neural implantations,and the development of smart brain-computer-interfaces^([2]).

关键词： conducting implantation additive

Catalytic production of high-energy-density spiro polycyclic jet fuel with biomass derivatives

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Journal of energy Chemistry 2025年第02期101卷 760-768页

作者： Wen-Jing Zhang yan-Cheng Hu yan-Hong Tan Jia li Ning li Jing-Pei Cao School of Chemical engineering and Technology China University of Mining and Technology CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

High-energy-density（HeD） fuel（*** used JP-10 and RJ-4）,featuring compact 3D polycyclic structure with high strain,is of critical importance for volume-limited military aircraft,since their high density and combustion heat can provide more propulsion *** reduce the reliance on petroleum source,it is highly desirable to develop renewable alternatives for the production of strained polycyclic HeD fuel,but which remains a big challenge because of the inaccessibility caused by the high strain,We herein demonstrate a three-step catalytic route towards highly strained C17and C18spirofuel with biomass *** process includes catalytic aldol condensation of renewable cyclohexanone/cyclopentanone with benzaldehyde,catalytic spiro Diels-Alder（D-A） reaction of aldol adduct with isoprene,and catalytic *** key spiro D-A reaction is enabled by the catalysis of heterogeneous Lewis acidic ionic *** chloroaluminate IL,formed by benign urea and AICl3,exhibits good catalytic performance and reusability for this *** eventual hydrodeoxygenation（HDO）over Pd/C and H-Y produces strained tricyclic spirofuel with density>0.93 g/mL,combustion heat>41 MJ/L and freezing point e better than the properties of tactical fuel ***,it is anticipated that the as-prepared renewable fuels have the potential to replace traditional petroleum-derived HeD fuels.

关键词： Biomass derivatives Cycloaddition High-energy-density Lewis acidic ionic liquid Spiro polycyclic fuel

The Study on Apparent Stress before and after the Minxian M_S6.6 earthquake on July 22,2013

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earthquake Research in China 2016年第2期30卷 193-207页

作者： Chen lijuan li yan'e yang liming Chen Jifeng Chen Xuezhong Gong liwen earthquake Administration of Chonqing Municipality Chongqing 401147China Institute of Geophysics CEABeijing 100081China earthquake Administration of Gansu Province Lanzhou 730000China

Based on the waveform data observed by the regional seismic network of Gansu Province,we calculated the apparent stress of 422 earthquakes with M_L≥ 2. 0 occurring in the surrounding area of the Minxian earthquake from January 2010 to July 2014 and obtained the temporal and spatial variation of apparent stress before and after the Minxian earthquake. Results show that( 1) the high value of apparent stress of earthquakes with M_L≥4. 0 was concentrated in the epicenter area before the Minxian earthquake while that of earthquakes with M_Lent stress around the epicenter area showed an obvious increasing process before the Minxian earthquake and the increasing process has continued after the main shock,which means that this study area is still in the danger of strong earthquakes.

关键词： The 2013 Minxian Ms6. 6 earthquake Apparent stress Temporal and spatialvariation

The Focal Mechanism Solutions of the M_S 8.0 Wenchuan earthquake in Sichuan on May 12,2008 and Some of Its Aftershocks

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earthquake Research in China 2010年第2期24卷 231-243页

作者： Guo Xiangyun Chen Xuezhong li yan＇e Institute of Geophysics China Earthquake Administration Beijing 100081 China

The focal mechanism solutions of the Wenchuan earthquake （Ms8.0） of May 12, 2008 and some of its aftershocks occurring up to December I0, 2008 are determined with lower semisphere of equal-projection and first motion sign data of P waves from regional and distant stations. The focal mechanism solutions of the Ms8.0 Wenchuan earthquake are： Nodal plane I：strike 5°, dip angle 48°, slip angle 39°; Nodal plane II： strike 247°, dip angle 62°, slip angle 131°; P axis azimuth 309°, plunge 8°, T axis azimuth 208°, plunge 54°, B axis azimuth 44°, plunge 35% Combining geological tectonics and spatial distribution of aftershocks, nodal plane II can be identified as a seismogenic fault. According to focal mechanism solutions, the fault activity that triggered the huge earthquake is reverse thrusting. The main rupture surface is S67°W, basically identical to the fault strike on which the earthquake occurred. The main compression stress P axis is N51°W, which is basically the same as the direction of the regional tectonic stress field. According to the results of focal mechanism solutions of aftershocks, the aftershocks occurring in the southern and northern sections of the Longmenshan fault zone have predominant orientations and are obviously different. For the main shock and the early aftershocks occurring on the southern section of the Longmenshan fault, the rupturing is mainly characterized by reverse-dip slip with some strike-slip, and over time, the aftershocks migrated towards the northern section. The rupturing in the source is mainly characterized by strike-slip with some reverse-dip slips. The stress field is controlled by the main shock stress field in the southern section of the Longmenshan tectonic zone, while it is controlled by the main shock stress field and regional stress field in the northern section of the Longmenshan tectonic zone.

关键词： First motion sign data Wenchuan earthquake sequence Focal mechanism

Temporal-spatial Variations of Dynamic Source Parameters in the Capital Circle Region and Its Surrounding Areas before the 2006 M_S5.1 Wenan earthquake in Hebei Province

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earthquake Research in China 2012年第1期26卷 20-32页

作者： Chen Xuezhong li yan'e Guo Xiangyun Institute of Geophysics CEABeijing 100081China

Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetry Seismic Network in the Capital Circle Region of China and its surrounding areas from January 2002 to June 2006 by the Brune *** formulas that were used for the calculation of dynamic source parameters include rupture radius,seismic moment,seismic energy,stress drop,and apparent *** relations and characteristics of temporal-spatial variations of these dynamic parameters before the MS5.1 Wenan earthquake in Hebei Province that occurred on July 20,2006 were *** show that apparent stress,stress drop,and the ratio of seismic energy to the rupture radius had relatively high values in some areas before the Wenan *** high-value concentration areas were mainly distributed in the North China Plain seismic *** is seen from the time curves,parameters,such as apparent stress,stress drop,and ratio of seismic energy to rupture radius underwent significant ascending processes before the Wenan earthquake,but the variation in the corner frequency showed a descending *** result might be related to the enhancement of stress in the North China Plain seismic zone before the earthquake.

关键词： Dynamic source parameter Temporal-spatial variation Wen'an earthquake The Capital Circle Region

The influence mechanism of environmental factors on DGT adsorbing sulfonamides and the migration between water and sediment

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Journal of environmental Sciences 2025年第5期151卷 347-359页

作者： Peng Zhang Jingfeng yan Hao Ji linke Ge yanying li School of environmental Science and Technology Shaanxi University of Science&TechnologyXi’an 710021China College of environmental Sciences and engineering Dalian Maritime UniversityDalian 116026China

Obtaining the sulfonamides(SAs)concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecological *** the present study,the influences of multifactor interactions on the performance of o-DGTs with XAD-18 binding gels were analyzed by central combination experiments and response surfaces analysis,in which the target compounds were 9 *** results indicated that dissolved organic matter(DOM),pH,and suspended particulate matter(SS)had significant effects on the o-DGT sampling,whereas this o-DGT was independent of the ionic strength(IS).Concentning the composite influence of the four factors,the interaction between DOM and SS posed the most significant effect on all 9 SAs ***,an o-DGT and DIFSmodel was applied to explore the SAs migration between the water-sediments *** difference between desorption rate(k_(b))and adsorption rates(k_(f))values suggested that the kinetics of SAs was dominated by ***,the short-term sediment-water partitioning of SAs was clarified on the basis of distribution coefficient(K_(dl))for the labile SAs,among which the sulfadiazine(SDZ)had the largest labile *** ability of sediments to release SAs to the liquid phase as a sink was determined by response time(T_(c)).Among the 9 SAs,the longterm release of soseulfamethoxypyridazine(SMP)from the solid phase of sediments would have a potential risk to the aquatic environment,to which more attention should be paid in the future.

关键词： Sulfonamides O-DGT Water-sediments interface DIFS Distribution

Bifurcations and Spatiotemporal Patterns in the Diffusive Nutrient-Microor ganism Model

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 162-178页

作者： Ya-di WANG Hai-long YUAN yan-ling li School of Arts and Sciences Shaanxi University of Science and TechnologyXi'an 710021China School of Mathematics and Statistics Xi'an Jiaotong UniversityXi'an 710049China School of Mathematics and Information Science Shaanxi Normal UniversityXi'an 710062China

In this paper,the diffusive nutrient-microorganism model subject to Neumann boundary conditions is *** Hopf bifurcations and steady state bifurcations which bifurcate from the positive constant equilibrium of the system are investigated in *** addition,the formulae to determine the direction of Hopf and steady state bifurcations are *** results show the existence of spatially homogeneous/nonhomogeneous periodic orbits and steady state solutions,which indicates the spatiotemporal dynamics of the *** numerical simulations are also presented to support the analytical results.

关键词： nutrient-microorganism model Hopf bifurcation steady state bifurcation simulations