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Nano Research 2025年第1期18卷 118-128页

作者： xiaofei chen Lixin Wu Feng Bai Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Center for High-Efficiency Display and Lighting TechnologySchool of Nanoscience and Materials EngineeringHenan UniversityKaifeng 475004China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China

The development of atmospheric pressure N_(2)reduction to NH_(3)is attracting much attention in green chemistry,yet it is still a challenge to obtain satisfactory activity under mild ***,an efficient near-infrared(NIR)photothermal catalysis reduction of N_(2)constitutes an occurrence is *** or without V-substitute polyoxometalates(POMs)loaded on the surface of Fechelated polydopamine(Fe-PDA)photothermal support through the electrostatic interactions,NIR photothermal catalysts POMs@Fe-PDA are *** induction of“FeV”cofactor facilitates electron transfer between V(V)/V(IV)&Fe(III)/Fe(II)and N_(2),thereby activating N_(2)*** synergy between the catalytic activity of V-POMs and the local NIR photothermal effect of Fe-PDA dramatically enhances N_(2)***,PMo_(10)V_(2)@Fe-PDA exhibits a significantly enhanced NH_(3)production rate of 181.1μmol·LN^(-1)with a turnover frequency of 1006.1 mmol·MN^(-1)·hN^(-1)under 808 nm NIR laser radiation,being the highest values reported at atmospheric *** expect that this work could provide an alternative approach for photothermal catalysis N_(2)reduction under mild conditions.

关键词： polyoxometalate near-infrared photothermal catalysis N_(2)reduction mild condition

Measurement of ice flow velocities from GPS positions logged by short-period seismographs in East Antarctica

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Science China Earth Sciences 2021年第8期64卷 1381-1389页

作者： Lei FU Jingxue GUO xiaofei chen Shenzhen Key Laboratory of Deep Offshore Oil and Gas Exploration Technology Southern University of Science and TechnologyShenzhen 518055China Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory for Polar Science MNRPolar Research Institute of ChinaShanghai 200136China

The ice flow velocity is a basic feature of glaciers and ice sheets. Measuring ice flow velocities is very important for estimating the mass balance of ice sheets in the Arctic and Antarctic. Traditional methods for measuring ice flow velocity include the use of stakes, snow pits and on-site geodetic GPS and remote sensing measurement methods. Geodetic GPS measurements have high accuracy, but geodetic GPS monitoring points only sparsely cover the Antarctic ice sheets. Moreover, the resolution and accuracy of ice flow velocities based on remote sensing measurements are low. Although the accuracy of the location data recorded by the navigation-grade GPS receivers embedded in short-period seismographs is not as good as that of geodetic GPS,the ice flow velocity can be accurately measured by these navigation-grade GPS data collected over a sufficiently long period. In this paper, navigation-grade GPS location data obtained by passive seismic observations during the 36 th Chinese National Antarctic Research Expedition were used to accurately track the movement characteristics of the ice sheet in the Larsemann Hills of East Antarctica and the Taishan Station area. The results showed that the ice sheet in the two study areas is basically moving northwestward with an average ice flow velocity of approximately 1 m mon-1. The results in the Taishan Station area are basically consistent with the geodetic GPS results, indicating that it is feasible to use the embedded GPS location data from shortperiod seismographs to track the movement characteristics of ice sheets. The ice flow characteristics in the Larsemann Hills are more complex. The measured ice flow velocities in the Larsemann Hills with a resolution of 200 m help to understand its characteristics. In summary, the ice flow velocities derived from GPS location data are of great significance for studying ice sheet dynamics and glacier mass balance and for evaluating the systematic errors caused by ice sheet movements in s

关键词： Short-period seismograph Antarctic ice sheet Ice flow velocity GPS

Inversion of near-field waveform data for earthquake source rupture process(Ⅱ):Inversion of Chi Chi earthquake source,20 September,1999,Taiwan

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Science China Earth Sciences 2006年第3期49卷 272-282页

作者： ZHOU Shiyong chen xiaofei Department of Geophysics Peking University Beijing 100871 China Department of Geophysics Peking University Beijing 100871 China

The new inversion algorithm developed based on the recent progress in thenonlinear programming study by us is used to invert the earthquake source process of Chi Chiearthquake M_w7.6, 20 Semptember,1999, Taiwan. A curve fault model is constructed in our inversionto make the fault model close to the real rupturing fault to reduce the influence from thediscrepancy between the constructed fault model and the real rupturing fault. The results show that(1) the rupture process of the Chi Chi earthquake source lasted about 32 seconds and the mainfaulting occurred between 6th to 21st second after the start of the ruptures and the high slip areawere mainly located at the northern segment of the fault. (2) The slip was dominated by thrustfaulting. The average rake angle was 64.5°, which was very consistent with those inverted by USGS,Harvard and CWB (Central Weather Bureau of Taiwan). The amount of the moment inverted in this paperwas 7.76x10^(20) NM, which was a slightly bigger than those inverted by USGS and Harvard. (3) Aclear nucleation step existed in the source faulting process and it lasted about 6 seconds. Themoment release rate accelerated obviously at the end of the nucleation step. The faulting startedfrom the southern segment and mainly occurred at the northern segment after 10 seconds. At the endof this paper, we analyzed the reliability of the inversion result via comparing with the GPSobservations and discussed its scientific signification.

关键词： Chi Chi earthquake, source rupture process, waveform inversion, near-source data, source mechanism.

Frequency-Bessel multi-mode surface wave tomography utilizing microseisms excited by energetic typhoons

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Science China Earth Sciences 2024年第11期67卷 3436-3447页

作者： Xuping FENG Yingjie XIA xiaofei chen Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Deep Offshore Oil and Gas Exploration Technology Southern University of Science and TechnologyShenzhen 518055China Guangdong Province Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055China College of Geophysics Chengdu University of TechnologyChengdu 610059China Institute of Risk Analysis Prediction and ManagementSouthern University of Science and TechnologyShenzhen 518055China

The recently developed Frequency-Bessel(F-J) transform array technique has significantly advanced multi-mode surface wave tomography, providing precise constraints on shear wave velocity(V_(S)) models of the crust and uppermost *** technique has primarily focused on extracting inter-station surface waves from ambient noise cross-correlation. Energetic typhoons generate abundant surface wave signals, prompting growing interest in utilizing these signals to investigate subsurface structures. This study explores the feasibility and application of using microseisms excited by strong typhoons for F-J transform surface wave tomography. By analyzing microseisms recorded by a broadband seismic array in Mongolia during energetic typhoons, we observed multi-mode surface waves with high signal-to-noise ratios. Our analysis revealed that the sources of these waves closely correspond to typhoon tracks, confirming that they were primarily excited by typhoons. We successfully extracted multi-mode dispersion curves for imaging the V_(S) structure beneath the array using the F-J transform. Additionally, we derived multi-mode dispersion curves from a two-year noise dataset recorded by the same array, which were also used to invert for the V_(S) structure. Comparison of V_(S) models derived from typhoon-induced microseisms and the two-year noise dataset showed negligible differences within the depth range of 0–140 km. Our findings demonstrate the potential value of microseisms generated by energetic typhoons in precisely probing the V_(S)structure of the crust and uppermost mantle.

关键词： Multi-mode surface wave tomography Typhoon-excited microseisms Frequency-Bessel transform Ambient noise cross-correlation Crustal and uppermost mantle structure

Numerical simulation of strong ground motion for the M_s8.0 Wenchuan earthquake of 12 May 2008

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Science China Earth Sciences 2008年第12期51卷 1673-1682页

作者： ZHANG Wei SHEN Yang chen xiaofei Graduate School of Oceanography University of Rhode IslandRI02882USA School of Earth and Space Science University of Science and Technology of ChinaHefei 230026China

The Wenchuan earthquake of 12 May 2008 is the most destructive earthquake in China in the past 30 years in terms of property damage and human losses. In order to understand the earthquake process and the geo-morphological factors affecting the seismic hazard, we simulated the strong ground mo-tion caused by the earthquake, incorporating three-dimensional (3D) earth structure, finite-fault rupture, and realistic surface topography. The simulated ground motions reveal that the fault rupture and basin structure control the overall pattern of the peak ground shaking. Large peak ground velocity (PGV) is distributed in two narrow areas: one with the largest PGV values is above the hanging wall of the fault and attributed to the locations of fault asperities and rupture directivity; the other is along the north-western margin of the Sichuan Basin and caused by both the directivity of fault rupture and the ampli-fication in the thick sediment basin. Rough topography above the rupture fault causes wave scattering, resulting in significantly larger peak ground motion on the apex of topographic relief than in the valley. Topography and scattering also reduce the wave energy in the forward direction of fault rupture but increase the PGV in other parts of the basin. These results suggest the need for a localized hazard as-sessment in places of rough topography that takes the topographic effects into account. Finally, had the earthquake started at the northeast end of the fault zone and ruptured to the southwest, chengdu would have suffered a much stronger shaking than it experienced on 12 May, 2008.

关键词： Wenchuan earthquake strong ground motion seismic hazard topography seismic wave modeling

High-resolution tsunami hazard assessment for the Guangdong-Hong Kong-Macao Greater Bay Area based on a non-hydrostatic tsunami model

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Science China Earth Sciences 2024年第7期67卷 2326-2351页

作者： Yifan ZHU Chao AN Houyun YU Wei ZHANG xiaofei chen Key Laboratory of Hydrodynamics(Ministry of Education) School of Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Earth and Space Sciences Southern University of Science and Technology Shenzhen 518055China

The Guangdong-Hong Kong-Macao Greater Bay Area(GBA)is threatened by potential tsunami hazards from the Littoral Fault Zone(LFZ)and the Manila subduction zone(MSZ),and may suffer huge damage because of its dense population,concentrated infrastructure,and low-lying *** tsunami studies for the GBA made simple assumptions on the mechanisms of LFZ earthquakes,and used coarse bathymetry data in tsunami simulation,which limited the prediction of detailed tsunami hazard *** this paper,we develop a parallel dispersive tsunami model PCOMCOT to efficiently simulate dispersive,nonlinear,and breaking tsunami *** also construct large-scale and high-resolution bathymetry models for the GBA by correcting and integrating various data *** rupture simulation is performed for the LFZ to obtain a more reliable earthquake source *** propose several representative earthquake scenarios for the LFZ and MSZ,and use PCOMCOT to calculate the resulting tsunami waves,currents,and inundation in the *** results indicate that if an M_(w)7.5 oblique-slip earthquake occurs in the LFZ off the Pearl River Estuary(PRE),the subsequent tsunami will primarily impact Hong Kong,causing maximum positive and negative waves of around 1 m and -2 m,respectively,along with slightly destructive currents(≥1.5 m/s).An M_(w)9.0 MSZ megathrust earthquake can lead to widespread inundation with>1 m depth on the outlying islands of Macao and in the urban areas of Hong Kong around the Victoria ***,it will also cause catastrophic tsunami currents along the narrow waterways in Hong Kong and Macao,and the spatial distribution of strong currents(≥3 m/s)shows a considerable discrepancy from the areas of serious ***,more attention should be paid to the potential impacts of tsunami currents on the GBA.

关键词： Tsunami hazards Inundation Tsunami currents Non-hydrostatic model Guangdong-Hong Kong-Macao Greater Bay Area

Dynamic rupture process of the 1999 Chi-Chi,Taiwan,earthquake

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Earthquake Science 2009年第1期22卷 3-12页

作者： Haiming Zhang xiaofei chen College of Earth Sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China

In this study, we preliminarily investigated the dynamic rupture process of the 1999 Chi-Chi, Taiwan, earthquake by using an extended boundary integral equation method, in which the effect of ground surface can be exactly included. Parameters for numerical modeling were carefully assigned based on previous studies. Numerical results indicated that, although many simplifications are assumed, such as the fault plane is planar and all heterogeneities are neglected, distribution of slip is still consistent roughly with the results of kinematic inversion, implying that for earthquakes in which ruptures run up directly to the ground surface, the dynamic processes are controlled by geometry of the fault to a great extent. By taking the common feature inferred by various kinematic inversion studies as a restriction, we found that the critical slip-weakening distance Dc should locate in a narrow region [60 cm, 70 cm], and supershear rupture might occur during this earthquake, if the initial shear stress before the mainshock is close to the local shear strength.

关键词： dynamic rupture 1999 Chi-Chi earthquake ground surface boundary integral equation method

Bioremediation Process and Bioremoval Mechanism of Heavy Metal Ions in Acidic Mine Drainage

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Chemical Research in Chinese Universities 2018年第1期34卷 33-38页

作者： ZHAO Ying FU Zhijing chen xiaofei ZHANG Guoyan College of Chemistry Jilin University Changehun 130012 P. R. China

Acidic mine drainage（AMD） containing acidity and a broad range of heavy metal ions is classified as hazardous, and must be properly treated. The removal mechanism of heavy metal ions in acidic mine drainage containing Cu^2＋, Fe^2＋, and Zn^2＋ with biological method was studied here. Using 20 mmol/L ethanol as carbon source, Desulfovibrio marrakechensis, one of sulfate reducing bacteria（SRB） species, grew best at 35℃ and pH=6.72 with concentrations of 10, 55 and 32 mg/L for Cu^2＋, Fe^2＋ and Zn^2＋, respectively. The removal efficiency for each ion mentioned above was 99.99%, 87.64% and 99.88%, respectively. The mineralogy and surface chemistry of precipitates were studied by means of energy dispersive spectrometer（EDS）, X-ray photoelectron spectroscopy（XPS）, X-ray diffraction（XRD） combined with control tests. The experimental results demonstrate that the removal mechanism of heavy metal ions by Desulfovibrio marrakechensis is comprehensive function of chemical precipitation, adsorption and bioprecipitation. The biogenic iron sulfide solid was characterized as greigite（Fe3S4）, while the zinc sulfide solid was characterized as sphalerite（ZnS）.

关键词： Acid mine drainage Sulfate reducing bacteria Heavy metal ion Precipitate Removal mechanism

Spectroscopic investigation of defects mediated oxidization of single-layer MoS_(2)

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Science China(Technological Sciences) 2021年第3期64卷 611-619页

作者： HE ZuYun GUO Zheng ZHONG Xiao chen xiaofei XUE JianMing WANG XinWei chen Yan School of Environment and Energy South China University of TechnologyGuangzhou 510006China School of Advanced Materials Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Due to the extremely large surface to bulk ratio,the properties of single layer(SL)MoS_(2)are largely determined by its interaction with *** critical interaction process that has been intensively investigated is the oxidation process of MoS_(2).Despite numerous previous explorations,the detailed mechanism regarding how MoS_(2)reacts with oxygen is still not well *** this work,we systematically investigate the impact of intrinsic and pre-created defects on the oxidation process of SL MoS_(2).For pristine SL MoS_(2),the oxidation is found to initiate near point defects and grain boundaries,leading to the formation of triangle pits in the basal plane and cracks near the grain *** pre-created defects introduced by ion irradiation are found to serve as the oxidation center,resulting in a more uniform oxidation *** oxidation is found to introduce p-type doping in the SL MoS_(2),leading to the blue shift of Raman and photoluminescence(PL)*** shift is found to be more for the region near the grain boundary and for the samples with more pre-created *** results suggest that the presence of defects can strongly promote the oxidation reaction of SL MoS_(2)in ambient condition,which significantly affects the stability and functionality of materials.

关键词： single layer MoS_(2) oxidation defect

Global seismic tomography reveals remnants of subducted Tethyan oceanic slabs in the deep mantle

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Science China Earth Sciences 2023年第12期66卷 2751-2769页

作者： Zewei WANG Jiashun HU Xueyang BAO Chunquan YU Yingjie YANG xiaofei chen Guangdong Provincial Key Laboratoryof Geophysical High-resolution Imaging Technology Southern University of Science and Technology Shenzhen 518055China Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China

The Tethyan evolution depicts the continuous process of landmasses separating from the Gondwana continent in the south,drifting northwards,and subsequently colliding with the continents in the north over the past 500 million *** this process,the Tethyan oceans that formed between the landmass and the southern or northern continents underwent growth,evolution,and eventual closure with the early Cenozoic India-Eurasia ***,the Tethyan lithosphere did not disappear but rather continued to evolve after entering into the deep *** current position,morphology,and volume of the subducted Tethyan oceanic slabs in the deep mantle record the latest moment of this continuous evolution,providing critical constraints for Tethyan *** paper summarizes and analyzes the results of global-scale whole-mantle seismic tomography in the past nearly two decades,revealing a northwest-southeast seismically high-velocity anomaly,which is linearly distributed at depths of 1000–2000 km beneath the Tethyan realm and referred to as the Tethyan *** searching for an optimal linear combination of previous global seismic tomographic models to best match the known subducted slabs in the upper mantle,we observe that the Tethyan anomaly extends approximately 8700 km in length and 2600 km in width,exhibiting a parallel structure with northern and southern *** geological records of oceanic subduction initiation and previous geodynamic studies,this study suggests that the main body of the Tethyan anomaly represents the remnants of the subducted Neo-Tethyan oceanic slabs,which subducted from the Late Jurassic to the early *** northern branch consists of subducted slabs from the Neo-Tethys beneath the southern margin of Eurasia,while the southern branch likely reflects the intra-oceanic subducted slabs of Neo-Tethys during the *** western portion of the Tethyan anomaly may reflect remnants of Paleo-Tethys,while the eastern portion,tow

关键词： Global seismic tomography Tethyan evolution Oceanic slabs Lower-mantle structure High-velocity anomaly