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A hybrid WUDT-NAFnet for simultaneous source data deblending

Petroleum Science 2024年第3期21卷 1649-1659页

作者： Chao-Fan Ke Shao-Huan Zu Jun-Xing Cao Xu-Dong Jiang Chao Li Xing-Ye Liu key laboratory of earth exploration and information technology of ministry of education Chengdu University of Technology State key laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of Technology College of Geophysics Chengdu University of Technology

Simultaneous source technology, which reduces seismic survey time and improves the quality of seismic data by firing more than one source with a narrow time interval, is compromised by the massive blended interference. Therefore, deblending algorithms have been developed to separate this interference.Recently, deep learning(DL) has been proved its great potential in suppressing the interference. The most popular DL method employs neural network as a filter to attenuate the blended noise in an iterative estimation and subtraction framework(IESF). However, there are still amplitude distortion and blended noise residual problems, especially when dealing with weak signal submerged in strong interference. To address these problems, we propose a hybrid WUDT-NAFnet, which contains two sub-networks. The first network is a wavelet based U-shape deblending transformer network(WUDTnet), incorporated into IESF as a robust regularization term to iteratively separate the blended interference. The second network is a nonlinear activate free network(NAFnet) designed to recover the event amplitude and further suppress the weak noise residual in IESF. With the hybrid network, the blended noise can be separated purposefully and accurately. Examples using synthetic and field seismic data demonstrate that the WUDTNAFnet outperforms traditional curvelet transform(CT) based method and the deblending transformer(DT) model in terms of deblending. Additionally, for field applications, the data augmentation method of bicubic interpolation is applied to mitigate the feature difference between synthetic and field data.Consequently, the trained network exhibits strong signal preservation ability in numerical field example without requiring additional training.

关键词： Simultaneous-source Deblending Deep learning Transformer

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Identifying and localizing of seismogenic electromagnetic anomalies from data observed by permanent MT stations

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Science China earth Sciences 2024年第5期67卷 1698-1713页

作者： Bing HAN Wenbao HU Guoze ZHAO Ji TANG State key laboratory of earthquake Dynamics Institute of GeologyBeijing 100029China key laboratory of exploration Technologies for Oil and Gas Resources of ministry of education Yangtze UniversityWuhan 430100China

In this research, an arbitrarily oriented electric dipole at subsurface is used to simulate Seismogenic Electromagnetic(SEM) radiation emanating from a seismic zone during its gestation phase. Analytical synthesis of responses at the Lijiang magnetotelluric(MT) station has revealed that SEM radiation could induce identifiable anomalies in the electromagnetic(EM)spectrum, apparent resistivity and phase within specific frequency bands. Background variations were extracted from long-term observation data of Dali and Lijiang MT stations, enabling the identification of SEM anomalies related to the Yunlong and Yangbi earthquakes. Multiple parameters of dipole sources at subsurface were obtained by applying the Differential Ant Colony Optimization(DACO) algorithm to anomalous data of two stations with multi-frequencies and various response functions. The spatial distribution of these predicted dipoles is predominantly clustered in or around the seismogenic area, with their azimuthal orientation aligning towards the seismogenic fault in general. This study has demonstrated the potential of using subsurface electric dipole simulations for SEM radiation analysis, offering a feasible approach for the prediction and understanding of seismogenic zones.

关键词： MT responses Identifying SEM anomaly Vector electric dipole responses Localizing SEM sources by inversion

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Identification of reservoir types in deep carbonates based on mixedkernel machine learning using geophysical logging data

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Petroleum Science 2024年第3期21卷 1632-1648页

作者： Jin-Xiong Shi Xiang-Yuan Zhao Lian-Bo Zeng Yun-Zhao Zhang Zheng-Ping Zhu Shao-Qun Dong key laboratory of exploration Technologies for Oil and Gas Resources of the ministry of education Yangtze University School of Geosciences Yangtze University College of Geosciences China University of Petroleum (Beijing) Petroleum exploration and Production Research Institute of SINOPEC School of earth Sciences and Engineering Xi'an Shiyou University

Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces. Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency, which cannot accurately reflect the nonlinear relationship between reservoir types and logging data. Recently, the kernel Fisher discriminant analysis(KFD), a kernel-based machine learning technique, attracts attention in many fields because of its strong nonlinear processing ability. However, the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well, especially for highly complex data cases. To address this issue, in this study, a mixed kernel Fisher discriminant analysis(MKFD) model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin, China. The MKFD model was trained and tested with 453 datasets from 7 coring wells, utilizing GR,CAL, DEN, AC, CNL and RT logs as input variables. The particle swarm optimization(PSO) was adopted for hyper-parameter optimization of MKFD model. To evaluate the model performance, prediction results of MKFD were compared with those of basic-kernel based KFD, RF and SVM models. Subsequently, the built MKFD model was applied in a blind well test, and a variable importance analysis was conducted. The comparison and blind test results demonstrated that MKFD outperformed traditional KFD, RF and SVM in the identification of reservoir types, which provided higher accuracy and stronger generalization. The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.

关键词： Reservoir type identification Geophysical logging data Kernel Fisher discriminant analysis Mixed kernel function Deep carbonates

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Quantitative characterizations of anisotropic dynamic properties in organic-rich shale with different kerogen content

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Petroleum Science 2024年第2期21卷 855-865页

作者： Jian-Yong Xie Yan-Ping Fang Xing-Hua Wu Jian'er Zhao Jun-Cheng Dai Jun-Xing Cao Ji-Xin Deng State key laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina key Lab of earth exploration&information Techniques of ministry of education Geophysical InstituteChengdu University of TechnologyChengdu610059SichuanChina PetroChina Southwest Oil&Gasfield Company Chengdu610017SichuanChina

Understanding the quantitative responses of anisotropic dynamic properties in organic-rich shale with different kerogen content(KC)is of great significance in hydrocarbon exploration and development.Conducting controlled experiments with a single variable is challenging for natural shales due to their high variations in components,diagenesis conditions,or pore fluid.We employed the hot-pressing technique to construct 11 well-controlled artificial shale with varying KC.These artificial shale samples were successive machined into prismatic shape for ultrasonic measurements along different directions.Observations revealed bedding perpendicular P-wave velocities are more sensitive to the increasing KC than bedding paralleling velocities due to the preferential alignments of kerogen.All elastic stiffnesses except C_(13)are generally decreasing with the increasing KC,the variation of C_(1) and C_(33)on kerogen content are more sensitive than those of C_(44)and C_(66).Apparent dynamic mechanical parameters(v and E)were found to have linear correlation with the true ones from complete anisotropic equations independent of KC,which hold value towards the interpretation of well logs consistently across formations,Anisotropic mechanical parameters(ΔE and brittlenessΔB)tend to decrease with the reducing KC,withΔB showing great sensitivity to KC variations.In the range of low KC(10%)shale,compilation of data from natural organic rich-shales globally verified the similar systematic relationships that can be empirically used to predict the fraction of KC in shales.

关键词： Elastic properties Organic shale Anisotropy Kerogen content Physical modeling

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UltrahighQ Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)microwave dielectric ceramics for temperature-stable millimeter-wave dielectric resonator antennas

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Journal of Advanced Ceramics 2024年第2期13卷 155-165页

作者： Guoqiang He Yu Jiang Kaixin Song Yanjun Liu Yuan Nie Wenjie Zhang Ziqi Zhao Yinghan He Xinyue Ma Xiuli Chen Xu Li Huanfu Zhou Collaborative Innovation Centre for exploration of Hidden Nonferrous Metal Deposits and Development of New Materials in Guangxi Key Laboratory of Nonferrous Materials and New Processing TechnologyMinistry of EducationSchool of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004China College of Electronic information Hangzhou Dianzi UniversityHangzhou 310018China

Microwave dielectric ceramics should be improved to advance mobile communication technologies further.In this study,we prepared Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics with nonstoichiometric Sr^(2+)ratios based on our previously reported SrY_(2)O_(4) microwave dielectric ceramic,which has a low dielectric constant and an ultrahigh quality factor(Q value).The ceramic exhibited a 33.6% higher Q-by-frequency(Q×f)value(Q≈12,500)at x=0.02 than SrY_(2)O_(4).All Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited pure phase structures,although variations in crystal-plane spacings were observed.The ceramics are mainly composed of Sr-O,Y1-O,and Y_(2)-O octahedra,with the temperature coefficient of the resonant frequency(τ_(f))of the ceramic increasing with Y_(2)-O octahedral distortion.The ceramic comprises uniform grains with a homogeneous elemental distribution,clear grain boundaries,and no obvious cavities at x=0.02.The Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited good microwave dielectric properties,with optimal performance observed at x=0.02(dielectric constant(εr)=15.41,Q×f=112,375 GHz,and τ_(f)=-17.44 ppm/℃).The τ_(f) value was reduced to meet the temperaturestability requirements of 5G/6G communication systems by adding CaTiO_(3),with Sr_(1.02)Y_(2)O_(4.02)+2wt% CaTiO_(3) exhibiting ε_(r)=16.14,Q×f=51,004 GHz,andτf=0 ppm/℃.A dielectric resonator antenna prepared using Sr_(1.02)Y_(2)O_(4.02)+2wt%CaTiO_(3) exhibited a central frequency of 26.6 GHz,with a corresponding gain and efficiency of 3.66 dBi and 83.14%,respectively.Consequently,Sr_(1.02)Y_(2)O_(4).02-based dielectric resonator antennas are suitable for use in 5G millimeter-wave band(24.5-27.5 GHz)applications.

关键词： millimeter wave microwave dielectric ceramics dielectric resonator antenna nonstoichiometric ratio

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Flexibility potential of Cs2BX6（B=Hf,Sn,Pt,Zr,Ti;X=I,Br,Cl）with application in photovoltaic devices and radiation detectors

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Journal of Energy Chemistry 2024年第8期95卷 271-287页

作者： Songya Wang Changcheng Chen Shaohang Shi Ziyi Zhang Yan Cai Shuli Gao Wen Chen Shuangna Guo Elyas Abduryim Chao Dong Xiaoning Guan Ying Liu Gang Liu Pengfei Lu School of Science Xi'an University of Architecture and Technology key laboratory of Eco Planning & Green Building Ministry of Education Tsinghua University State key laboratory of information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Physics and Optoelectronic Engineering Ludong University

As interest in double perovskites is growing,especially in applications like photovoltaic devices,understanding their mechanical properties is vital for device durability.Despite extensive exploration of structure and optical properties,research on mechanical aspects is limited.This article builds a vacancyordered double perovskite model,employing first-principles calculations to analyze mechanical,bonding,electronic,and optical properties.Results show Cs2Hfl6,Cs2SnBr6,Cs2SnI6,and Cs2PtBr6have Young's moduli below 13 GPa,indicating flexibility.Geometric parameters explain flexibility variations with the changes of B and X site composition.Bonding characteristic exploration reveals the influence of B and X site electronegativity on mechanical strength.Cs2SnBr6and Cs2PtBr6are suitable for solar cells,while Cs2HfI6and Cs2TiCl6show potential for semi-transparent solar cells.Optical property calculations highlight the high light absorption coefficients of up to 3.5 ×10～5 cm-1for Cs2HfI6and Cs2TiCl6.Solar cell simulation shows Cs2PtBr6achieves 22.4% of conversion effciency.Cs2ZrCl6holds promise for ionizing radiation detection with its 3.68 eV bandgap and high absorption coefficient.Vacancy-ordered double perovskites offer superior flexibility,providing valuable insights for designing stable and flexible devices.This understanding enhances the development of functional devices based on these perovskites,especially for applications requiring high stability and flexibility.

关键词： Double perovskite Flexible Mechanical properties Photovoltaic Radiation detectors

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Record-breaking summer-autumn drought in southern China in 2022:Roles of tropical sea surface temperature and Eurasian warming

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Science China earth Sciences 2024年第2期67卷 420-431页

作者： Yuepeng HU Botao ZHOU Huijun WANG Dapeng ZHANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/key laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing210044China

From summer to autumn in 2022,a severe drought lasted in southern China,posing serious effects on economic growth and ecological systems.This study explored the atmospheric circulations accounting for this persistent drought event.It shows that the drought in southern China during the summer of 2022 was strongly linked to the divergence of water vapor flux and descending motions,which were respectively caused by the anomalous anticyclone over the western North Pacific and the northward movement of the East Asian subtropical jet(EASJ).Differently,the atmospheric background responsible for the sustained drought in autumn is manly featured by a cyclonic circulation anomaly over the region from the Bay of Bengal to the South China Sea,which led to decreased moisture and descending motions in southern China.Further investigation suggests that the rarely strong surface warming over northern Eurasia and the extreme La Nina-like pattern over the tropical Pacific jointly resulted in the anomalous anticyclone over the western North Pacific and the northward shift of the EASJ in the summer of 2022,while the cyclonic circulation anomaly prevailing over the region from the Bay of Bengal to the South China Sea in autumn was largely attributed to the extremely negative anomalies of the tropical Indian Ocean sea surface temperature.

关键词： Summer-autumn drought Southern China Tropical sea surface temperature Eurasian warming

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Health benefits from the rapid reduction in ambient exposure to air pollutants after China's clean air actions:progress in efficacy and geographic equality

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National Science Review 2024年第2期11卷 103-113页

作者： Tao Xue Ruohan Wang Meng Wang Yanying Wang Dan Tong Xia Meng Conghong Huang Siqi Ai Fangzhou Li Jingyuan Cao Mingkun Tong Xueqiu Ni Hengyi Liu Jianyu Deng Hong Lu Wei Wan Jicheng Gong Shiqiu Zhang Tong Zhu Clean Air Asia Institute of Reproductive and Child Health National Health Commission Key Laboratory of Reproductive Health/Department of Epidemiology and Biostatistics Ministry of Education Key Laboratory of Epidemiology of Major Diseases(PKU) School of Public Health Peking University Health Science Centre State Environmental Protection key laboratory of Atmospheric Exposure and Health Risk Management and Center for Environment and Health Peking University Advanced Institute of information technology Peking University Department of Epidemiology and Environmental Health School of Public Health and Health ProfessionsUniversity at Buffalo State key Joint laboratory of Environment Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University Department of earth System Science Tsinghua University School of Public Health Key Laboratory of Public Health Safety of the Ministry of Education and Key Laboratory of Health Technology Assessment of the Ministry of HealthFudan University College of Land Management Nanjing Agricultural University National&Local Joint Engineering Research Center for Rural Land Resources Use and Consolidation

Clean air actions （CAAs） in China have been linked to considerable benefits in public health.However,whether the beneficial effects of CAAs are equally distributed geographically is unknown.Using high-resolution maps of the distributions of major air pollutants (fine particulate matter[PM2.5]and ozone[O3]) and population,we aimed to track spatiotemporal changes in health impacts from,and geographic inequality embedded in,the reduced exposures to PM2.5and O3from 2013 to 2020.We used a method established by the Global Burden of Diseases Study.By analyzing the changes in loss of life expectancy（LLE） attributable to PM2.5and O3,we calculated the gain of life expectancy （GLE） to quantify the health benefits of the air-quality improvement.Finally,we assessed the geographic inequality embedded in the GLE using the Gini index （GI）.Based on risk assessments of PM2.5and O3,during the first stage of CAAs（2013 to 2017）,the mean GLE was 1.87 months.Half of the sum of the GLE was disproportionally distributed in about one quarter of the population exposed （GI 0.44）.During the second stage of CAAs（2017 to 2020）,the mean GLE increased to 3.94 months and geographic inequality decreased （GI 0.18）.According to our assessments,CAAs were enhanced,from the first to second stages,in terms of not only preventing premature mortality but also ameliorating health inequalities.The enhancements were related to increased sensitivity to the health effects of air pollution and synergic control of PM2.5and O3levels.Our findings will contribute to optimizing future CAAs.

关键词： clean air action public health inequality fine particulate matter ozone

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High-precision modeling of tide-induced 3-D magnetic field and analysis of geomagnetic satellite orbit requirements

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Science China earth Sciences 2024年第1期67卷 165-178页

作者： Zhengyong REN Cong YANG Hongbo YAO Xu TANG Jingtian TANG Keke ZHANG key laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring ministry of education Central South UniversityChangsha 410083China Hunan key laboratory of Nonferrous Resources and Geological Hazards exploration Changsha 410083China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China State key laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 999078China

Ground-based magnetic observatories and geomagnetic satellites can observe the induced magnetic field generated by the motion of seawater containing sodium and chlorine ions.Calculating the three-dimensional(3-D)spatial distribution of tide-induced magnetic fields(TIMF)is crucial for inverting the electrical conductivity structure of the oceanic lithosphere.It also serves as an essential basis for designing optimal geomagnetic observatories and satellite orbits.However,existing methods for simulating TIMF suffer from limitations in inaccurately modeling realistic coastlines,heterogeneous land and sea surface properties,and complex deep earth structures,thereby the interpretational level of TIMF data is reduced.To overcome this issue,we developed a tetrahedral-based finite element method for simulating TIMF,which can efficiently approximate realistic coastlines,heterogeneous land and sea surface properties,and complex deep earth structures.Firstly,we derived the boundary value problem for the seawater motion-induced electromagnetic field,which was solved using the vector finite element method based on tetrahedral elements.Secondly,using the latest ocean depth and seafloor sediment layer models,we constructed a 3-D conductivity model of the earth,which includes realistic coastlines,heterogeneous land and sea conductivity distributions.We then computed the TIMF using the M_(2)tidal source as an example and validated our method by comparing it with results obtained from spherical harmonic finite element and integral equation methods.Finally,utilizing the computed high-precision M_(2),N_(2),and O1 TIMF signals,we marked global observatories capable of observing strong M_(2),N_(2),and O1 TIMF signals and predicted alternative stations suitable for tide signal observations.Additionally,we calculated TIMF at heights of 450 and 200 km for the Macao Science Satellite 1 and its subsequent satellites.The results indicate that the amplitude of the tidal-induced magnetic field at 200 km is approximately twice that at 450 km.Th

关键词： Ocean motional induction Electromagnetic induction Ocean tides Geomagnetic satellite Macao Science Satellite 1

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Highly selective and efficient photocatalytic NO removal:Charge carrier kinetics and interface molecular process

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Nano Research 2024年第3期17卷 1003-1026页

作者： Huan Shang Hongbao Jia Pengpeng Li Hao Li Wenbin Zhang Shuangjun Li Qing Wang Shuning Xiao Ding Wang Guisheng Li Dieqing Zhang School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China The education ministry key Lab of Resource Chemistry Joint International Research Laboratory of Resource Chemistry of Ministry of EducationShanghai Key Laboratory of Rare Earth Functional Materialsand Shanghai Frontiers Science Center of Biomimetic CatalysisShanghai Normal UniversityShanghai 200234China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The widespread nitrogen oxides(NOx,mainly in NO)in the atmosphere have threatened human health and ecological environment.The dilute NO(ppb)is difficult to efficiently remove via the traditional process due to its characteristics of low concentration,wide range,large total amount,etc.Photocatalysis can utilize solar energy to purify NO pollutants under mild conditions,but its application is limited due to the low selectivity of nitrate and poor activity of NO removal.The underlying reason is that the interface mechanism of NO oxidation is not clearly understood,which leads to the inability to accurately regulate the NO oxidation process.Herein,the recent advances in the photocatalytic oxidation of NO are summarized.Firstly,the common strategies to effectively regulate carrier dynamics such as morphology control,facet engineering,defect engineering,plasma coupling,heterojunction and single-atom catalysts are discussed.Secondly,the progress of enhancing the adsorption and activation of reactants such as NO and O_(2) during NO oxidation is described in detail,and the corresponding NO oxidation mechanisms are enumerated.Finally,the challenges and prospects of photocatalytic NO oxidation are presented in term of nanotechnology for air pollution control.This review can shed light on the interface mechanism of NO oxidation and provide illuminating information on designing novel catalysts for efficient NOx control.

关键词： nitrogen oxide(NO)oxidation photocatalysis NO/O_(2)activation charge carrier kinetics interfacial mechanism

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