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Stress triggering effect on the 2022 Honghe m_(S)5.0 earthquake with historical strong earthquakes

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Geodesy and Geodynamics 2024年第2期15卷 107-113页

作者： mingce wang Zifeng Liu Ruijie Luo Yunnan Earthquake Agency Kunming 650224China School of Earth Sciences Yunnan UniversityKunming 650504China

The 2022 Honghe m_(S)5.0 seismic event is intriguing due to its occurrence in the south of the Red River Fault,an area historically lacking seismic activities greater than m_(S)*** elucidate the seismogenic mechanism and scrutinize stress-triggered interactions,we calculated co-seismic and post-seismic Coulomb stress alterations induced by nine historical seismic events(m≥6.0).The analysis reveals that these substantial seismic events provoked co-seismic stress augmentations of 1.409 bar and postseismic stress increments of 0.159 *** seismic events,such as the 1833 Songming,1877Shiping,1913 Eshan,and 1970 Tonghai earthquakes,catalyzed the occurrence of the Honghe *** of heightened future seismic risk include the southern region of the Red River Fault and the eastern segments of the Shiping-Jianshui and Qujiang ***,we assessed the correlation between the spatial distribution of aftershocks and the Coulomb stress shift triggered by the m.inshock,taking into account the influence of calculation parameter settings.

关键词： Honghe ms5.0 earthquake Coulomb failurestress Stress triggering Historical strongearthquakes

Coseismic Coulomb stress changes induced by a 2020-2021 m_(W)>7.0 Alaska earthquake sequence in and around the Shumagin gap and its influence on the Alaska-Aleutian subduction interface

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Geodesy and Geodynamics 2024年第1期15卷 1-12页

作者： Lei Yang Jianjun wang Caijun Xu School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China Collaborative innovation Center of Geospatial Technology Wuhan 430079China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan UniversityWuhan 430079China

Three m_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the mw7.8 Simeonof thrust earthquake on July 22,2020,the m_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the m_(W)8.2 Chignik thrust earthquake on July 29,*** spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among *** we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction *** results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,*** Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%*** factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these m.inshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.

关键词： The 2020-2021 Alaska earthquake sequence Coseismic Coulomb stress change m.inshock-aftershock triggering The Alaska-Aleutian subduction interface The Shumagin gap

Biotransformation of 6:2 fluorotelomer sulfonate (6:2 FTS) in sulfur-rich media by Trametopsis cervina

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FRONTiERS OF ENViRONmENTAL SCiENCE & ENGiNEERiNG 2024年第9期18卷 107-0页

作者： Grimberg, Felix Holsen, Thomas m. Fernando, Sujan wang, Siwen Clarkson Univ Dept Civil & Environm Engn Potsdam NY 13699 USA

Biotransformation of 6:2 fluorotelomer sulfonate (6:2 FTS) by two species of white-rot fungi, Pleurotus ostreatus (P. ostreatus) and Trametopsis cervina (T. cervina), was investigated in a sulfur-rich medium designed to stimulate production of lignin-degrading enzymes. Degradation of 6:2 FTS was observed by T. cervina over the study period of 30 d, but not by P. ostreatus. Biotransformation rates were comparable to those found in other studies investigating mixed culture degradation in non-sulfur limiting media, with approximately 50 mol% of applied 6:2 FTS removed after 30 d. Stable transformation products were short-chain perfluorocarboxylic acids (PFCAs), including PFHxA (2.27 mol%), PFPeA (0.24 mol%), and PFBA (0.28 mol%). The m.in intermediate products include 5:2 sFTOH (16.3 mol%) and 5:3 FTCA (2.99 mol%), while 6:2 FTCA, 6:2 FTuCA, and 5:2 ketone were also identified at low levels. Approximately 60 mol% of detected products were assigned to the major pathway to 5:2 ketone, and 40 mol% were assigned to the minor pathway to 5:3 FTCA. The overall molar balance was found to decrease to 75 mol% by Day 30, however, was closed to near 95 mol% with a theoretical estimation for the volatile intermediates in the headspace, 5:2 ketone and 5:2 sFTOH. The different capabilities of the two white-rot fungal species for 6:2 FTS biotransformation in sulfur-rich media suggest that the enzyme processes of T. cervina to de-sulfonate 6:2 FTS may be unrelated to sulfur metabolism. (c) Higher Education Press 2024

关键词： White-rot fungus 6:2 fluorotelomer sulfonate (6:2 FTS) Biotransformation Sulfur-rich medium intermediate products FiLm-FORmiNG FOAm WHiTE-ROT POLYFLUOROALKYL SUBSTANCES PERFLUOROOCTANOiC ACiD PLEUROTUS-OSTREATUS LACCASE PRODUCTiON DEGRADATiON PERFLUOROALKYL GROUNDWATER SURFACTANTS

Assessment of spongy moth infestation impacts on forest productivity and carbon loss using the Sentinel-2 satellite remote sensing and eddy covariance flux data

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Ecological Processes 2024年第2期13卷 231-245页

作者： Nur Hussain Alemu Gonsamo Shusen wang m.Altaf Arain School of Earth Environment and Society and McMaster Centre for Climate Change Mc Master University Canada Centre for Remote Sensing Natural Resources Canada

Background Deciduous forests in eastern North America experienced a widespread and intense spongy moth（Lymantria dispar） infestation in 2021. This study quantified the impact of this spongy moth infestation on carbon（C） cycle in forests across the Great Lakes region in Canada, utilizing high-resolution（10 × 10 m2） Sentinel-2 satellite remote sensing images and eddy covariance（EC） flux data. Study results showed a significant reduction in leaf area index（LAi） and gross primary productivity（GPP） values in deciduous and mixed forests in the region in *** Remote sensing derived, growing season mean LAi values of deciduous（mixed） forests were 3.66（3.18）, 2.74（2.64）, and 3.53（2.94） m2m-2in 2020, 2021 and 2022, respectively, indicating about 24（14）% reduction in LAi, as compared to pre-and post-infestation years. Similarly, growing season GPP values in deciduous（mixed） forests were 1338（1208）, 868（932）, and 1367（1175） g C m-2, respectively in 2020, 2021 and 2022, showing about 35（22）% reduction in GPP in 2021 as compared to pre-and post-infestation years. This infestation induced reduction in GPP of deciduous and mixed forests, when upscaled to whole study area（178,000 km2）, resulted in 21.1（21.4） mt of C loss as compared to 2020（2022）, respectively. it shows the large scale of C losses caused by this infestation in Canadian Great Lakes *** The methods developed in this study offer valuable tools to assess and quantify natural disturbance impacts on the regional C balance of forest ecosystems by integrating field observations, high-resolution remote sensing data and models. Study results will also help in developing sustainable forest management practices to achieve net-zero C emission goals through nature-based climate change solutions.

关键词： Spongy moth infestation Carbon Gross ecosystem productivity Leaf area index Temperate forest Remote sensing Sentinel-2 Eddy covariance

A proposal for detecting weak electromagnetic waves around 2.6μm wavelength with Sr optical clock

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Chinese Physics B 2024年第4期33卷 452-457页

作者：韩弱水王伟汪涛 Department of Physics and Chongqing Key Laboratory for Strongly Coupled PhysicsChongqing UniversityChongqing 401331China Center of modern Physics Institute for Smart City of Chongqing University in LiyangLiyang 213300China State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi UniversityTaiyuan 030006China

infrared signal detection is widely used in many *** to the detection principle,however,the accuracy and range of detection are *** to the ultra stability of the^(87)Sr optical lattice clock,external infrared electromagnetic wave disturbances can be responded *** the ac Stark shift of the clock transition,we propose a new method to detect infrared *** to our calculations,the theoretical detection accuracy in the vicinity of its resonance band of 2.6μm can reach the order of 10-14W,while the minimum detectable signal of common detectors is on the order of 10^(-10)W.

关键词： infrared signal detection ^(87)Sr optical lattice clock ac Stark shift ultra stability

Effectiveness of external prestressing in enhancing the non-ductile hanger failure mechanism.in reinforced concrete inverted T-beams

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1050-1065页

作者： Ahmed m.ATTA Reda N.BEHiRY mohammed i.HARAZ Structural Engineering Department Faculty of EngineeringTanta UniversityTanta 33511Egypt Nile Higher institute for Engineering and Technology Mansoura 11001Egypt

Recently,inverted T-beams have been used in reinforced concrete(RC)bridges to support transverse precast *** T-beams,contrary to practice with conventional beams,are loaded on the flanges upper *** loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the *** key purpose of this study is to investigate the efficiency of vertical external prestressing stainless-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted *** experimental study on six inverted-T beams,including two un-strengthened specimens,was carried *** study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism.in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and *** experimental results indicated that the suggested method for strengthening inverted T-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53% when compared to that of the un-strengthened ***,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted T-beams were *** models that were proposed exhibited a high degree of agreement with the experimental results.

关键词： RC bridges inverted T-beams strengthening hanger failure external prestressing

Seismicity changes and numerical simulation of coseismic deformation following the 2022 m_(s)6.8 Luding earthquake in Sichuan,China

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Science China Earth Sciences 2024年第8期67卷 2507-2521页

作者： Qiu mENG Zitao wang Huai ZHANG Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China Southern marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Beijing Yanshan Earth Critical Zone National Research Station Beijing 101408China

The Xianshuihe fault is a major tectonic boundary between the Sichuan-Yunnan rhom.ic and Bayanhar blocks in Southwest *** an average left-lateral strike-slip movement of 10–15 mm/yr,it is a fast-moving strike-slip continental *** September 5,2022,the ms6.8 Luding earthquake occurred along the moxi segment of the Xianshuihe fault,reaching a maximum.intensity of iX and resulting in a significant number of casualties and severe property *** earthquake broke the long-standing seismic quiescence of the Xianshuihe fault,which lasted for more than 40 years,and was followed by a significant number of *** outstanding question is how the behavior of the Xianshuihe fault and major earthquakes changed following this *** this study,we examined the changes in regional seismicity following the Luding earthquake and identified the potential for future strong earthquakes along the Xianshuihe *** used a finite element numerical method to simulate the environment of the seismogenic fault and its adjacent *** addition,we used the coseismic slip model of the Luding earthquake with the split-node method to calculate how the stress and strain fields in the surrounding area were affected by the2022 *** stress changes were resolved in the m.in faults,and the seismicity of adjacent faults was analyzed in conjunction with the observed seismic *** results indicate that regional tectonic movement primarily occurred to the southeast along the moxi *** stress field is approximately north-south in tension and east-west in *** in the stress field in the epicentral region of the Luding earthquake exceeded 1 *** maximum displacement of the coseismic deformation field was concentrated between moxi town and Tuanjie village,and the Coulomb stress of the fault zone in this region experienced the largest ***,the b-value of the Gutenberg-Richter magnitude-frequency relationship at the epicenter a

关键词： Luding earthquake Seismicity Coulomb failure stress change Finite element numerical simulation

A native herbaceous community exerts a strong allelopathic effect on the woody range-expander Betula fruticosa

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Journal of Plant Ecology 2024年第4期17卷 131-140页

作者： Lichao wang Ayub m.O.Oduor Yanjie Liu State Key Laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China Department of Applied Biology Technical University of KenyaNairobiKenya

Biological invasions by alien and range-expanding native plant species can suppress native plants through ***,the homeland security hypothesis suggests that some native plants can resist invasion by producing allelopathic compounds that inhibit the growth of invasive *** research has focused on allelopathic interactions between individual native and invasive plant species,with less emphasis on how allelopathy helps entire native communities resist ***,limited knowledge exists about allelopathic interactions between range-expanding native species and recipient native communities,and their influence on invasion *** bridge this knowledge gap,we conducted two greenhouse competition experiments to test reciprocal allelopathic effects between a native woody range-expanding species,Betula fruticosa,and a community of four native herbaceous species(Sanguisorba officinalis,Gentiana manshurica,Sium suave and Deyeuxia angustifolia)in *** assessed whether *** and the native community differed in their competitive effects and responses,and whether these were influenced by activated carbon,which neutralizes allelochemicals in the *** carbon reduced the suppressive effects of the native community on the above-ground biomass of ***,which indicates that the native community exerted a strong allelopathic effect on *** contrast,activated carbon only marginally enhanced the suppressive effects of *** on the native community,which indicates that allelopathy is not the primary mechanism by which *** exerts its ***,these findings support the homeland security hypothesis and suggest that biotic resistance from the native herbaceous community may limit the invasion success of the woody range-expander ***.

关键词： allelochemicals competition encroachment global change non-native shrub

Developing a two-decadal time-record of rice field maps using Landsat-derived multi-index image collections with a random forest classifier:A Google Earth Engine based approach

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information Processing in Agriculture 2024年第2期11卷 260-275页

作者： W.Ashane m.Fernando i.P.Senanayake Department of Nano Science Technology Wayamba University of Sri LankaKuliyapitiya 60200Sri Lanka Dchoolf Engineing CllegeoEngineeringSience and EnionmentThe UniversyewcastleCallaghanW2Austraia

Historic maps showing the temporal distribution of rice fields are important for precision agriculture,irrigation optimisation,forecasting crop yields,land use management and formulating ***,mapping rice felds using traditional ground surveys is impractical when high cost,time and labour requirements are considered,and the availability of such detailed records is *** satellite remote sensing appears to be a viable solution,conventional segmentation and classification methods with spectral bands are often unable to contrast the distinct characteristics between rice fields and other vegetation *** this end,we explored a novel,Google Earth Engine(GEE)based multiindex random forest(RF)classification approach to map rice fields over two *** images from 2000 to 2020 of two Sri Lankan rice cultivation districts were extracted from GEE and a multi-index RF classification algorithm was applied to distinguish the rice *** results showed above 80%accuracy for both training and validation,when compared against high spatial resolution Google Earth *** essence,multi-index sampling and RF together synergised the compelling classifcation accuracy by effectively capturing vegetation,water(ponding)and soil characteristics unique to the rice felds using a single-click *** maps developed in this study were further compared against the mODiS land cover type product(mCD12Q1)and the corresponding superior statistics on rice fields demonstrated the robustness of the proposed *** work seeking effective index com.inations is recommended,and this approach can potentially be extended to other crop analyses elsewhere.

关键词： Google Earth Engine(GEE) image classification Random forest mapping rice fields Time series analysis Vegetation index