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Influence of different data selection criteria on internal geomagnetic field modeling 被引量:4
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作者 HongBo Yao JuYuan Xu +3 位作者 Yi Jiang Qing Yan Liang Yin pengfei liu 《Earth and Planetary Physics》 2025年第3期541-549,共9页
Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these i... Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these internal magnetic fields accurately,data selection based on specific criteria is often employed to minimize the influence of rapidly changing current systems in the ionosphere and magnetosphere.However,the quantitative impact of various data selection criteria on internal geomagnetic field modeling is not well understood.This study aims to address this issue and provide a reference for constructing and applying geomagnetic field models.First,we collect the latest MSS-1 and Swarm satellite magnetic data and summarize widely used data selection criteria in geomagnetic field modeling.Second,we briefly describe the method to co-estimate the core,crustal,and large-scale magnetospheric fields using satellite magnetic data.Finally,we conduct a series of field modeling experiments with different data selection criteria to quantitatively estimate their influence.Our numerical experiments confirm that without selecting data from dark regions and geomagnetically quiet times,the resulting internal field differences at the Earth’s surface can range from tens to hundreds of nanotesla(nT).Additionally,we find that the uncertainties introduced into field models by different data selection criteria are significantly larger than the measurement accuracy of modern geomagnetic satellites.These uncertainties should be considered when utilizing constructed magnetic field models for scientific research and applications. 展开更多
关键词 Macao Science Satellite-1 SWARM geomagnetic field modeling data selection core field crustal field
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Revised global vertically integrated remanent magnetization model of the oceanic lithosphere with comparison to LCS-1 model and MSS-1 magnetic measurements 被引量:2
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作者 ShiDa Sun Hui Li +3 位作者 JinSong Du Pan Zhang Chao Chen pengfei liu 《Earth and Planetary Physics》 2025年第3期653-666,共14页
The lithospheric magnetic field is an important component of the geomagnetic field,and the oceanic lithosphere exhibits distinct characteristics.Because of its formation mechanisms,evolutionary history,and geomagnetic... The lithospheric magnetic field is an important component of the geomagnetic field,and the oceanic lithosphere exhibits distinct characteristics.Because of its formation mechanisms,evolutionary history,and geomagnetic field polarity reversals,the oceanic lithosphere has significant remanent magnetization,which causes magnetic anomaly stripes parallel to the mid-ocean ridges.However,it is difficult to construct a high-resolution lithospheric magnetic field model in oceanic regions with relatively sparse data or no data.Using forward calculated lithospheric magnetic field data based on an oceanic remanent magnetization(ORM) model with physical and geological foundations as a supplement is a feasible approach.We first collect the latest available oceanic crust age grid,plate motion model,geomagnetic polarity timescale,and oceanic lithosphere thermal structure.Combining the assumptions that the paleo geomagnetic field is a geocentric axial dipole field and that the normal oceanic crust moves only in the horizontal direction,we construct a vertically integrated ORM model of the normal oceanic crust with a known age,including the intensity,inclination,and declination.Both the ORM model and the global induced magnetization(GIM) model are then scaled from two aspects between their forward calculated results and the lithospheric magnetic field model LCS-1.One aspect is the difference in their spherical harmonic power spectra,and the other is the misfit between the grid data over the oceans.We last compare the forward calculated lithospheric magnetic anomaly from the scaled ORM and GIM models with the Macao Science Satellite-1(MSS-1) observed data.The comparison results show that the magnetic anomalies over the normal oceanic crust regions at satellite altitude are mainly contributed by the high-intensity remanent magnetization corresponding to the Cretaceous magnetic quiet period.In these regions,the predicted and observed anomalies show good consistency in spatial distribution,whereas their amplitude differences vary across regions.This result suggests that regional ORM construction should be attempted in future work to address these amplitude discrepancies. 展开更多
关键词 oceanic remanent magnetization lithospheric magnetic field LCS-1 Macao Science Satellite-1
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Comprehensive evaluation of the vector magnetic field data from Macao Science Satellite-1A 被引量:1
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作者 XinYi Rang Chao Xiong +7 位作者 YuYang Huang ChunYu Xu FengJue Wang BoHao Qian Fan Yin SiShan Song Keke Zhang pengfei liu 《Earth and Planetary Physics》 2025年第3期521-531,共11页
In this study,we present a comprehensive evaluation of the magnetic field measurements from the Vector Field Magnetometer(VFM)aboard the recently launched Macao Science Satellite-1(MSS-1).One-year data from November 2... In this study,we present a comprehensive evaluation of the magnetic field measurements from the Vector Field Magnetometer(VFM)aboard the recently launched Macao Science Satellite-1(MSS-1).One-year data from November 2,2023,to November 1,2024,are considered.The MSS-1 flies with a low inclination(41°)and is designed to provide high-resolution magnetic field measurements,especially for monitoring the evolution of the South Atlantic Anomaly.Earlier studies confirmed the possibility of using MSS-1A data to model the Earth’s main magnetic field(e.g.,Jiang Y et al.,2024).Therefore,in this study we focus on the magnetic signatures related to the external field,which are primarily associated with magnetospheric and ionospheric currents.The global distributions of the magnetic residuals from MSS-1A show a pattern consistent with that derived from the European Space Agency’s Swarm A satellite.A statistical survey of the conjugated observations(withΔt<5 min andΔR<150 km)between the two satellites showed that the difference between their magnetic residuals is within±3 nanoteslas.By separating the magnetic residuals at the noon and midnight hours,we see that the MSS-1A data can effectively capture features of the magnetospheric and ionospheric currents,such as the magnetospheric ring current and ionospheric equatorial electrojet.Moreover,the magnetic residuals from MSS-1A show a diamagnetic effect caused by post-sunset equatorial plasma bubbles,which also suggests that the MSS-1A data have the potential to reveal the ionospheric structures.The comprehensive evaluations performed within this study demonstrate that the MSS-1A provides high-quality magnetic field data reaching the level of the Swarm satellite,which enables a deeper understanding of the modeling of Earth’s magnetic field as well as monitoring of the magnetic environment. 展开更多
关键词 MSS satellite magnetic field residuals ring current equatorial electrojet diamagnetic effect
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Technical characteristics of Macao Science Satellite-1A 被引量:1
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作者 Yan Li Yong Zhang +13 位作者 TianYu Zhang ShiGeng Yuan Wen Su JingShan Sun Fei Feng BingJun Cheng Yi Jiang pengfei liu GuiHong Xiao QingMei Fan ChunYu Yu Ming Wang Qi Xiao ChuNan Miao 《Earth and Planetary Physics》 2025年第3期491-499,共9页
The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importa... The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importance in China’s space exploration endeavors.Among these,MSS-1A is the world’s first high-precision scientific satellite dedicated to exploring the geomagnetic field and space environment at low latitudes.Equipped with two high-precision vector magnetometers and one scalar magnetometer,which are integrally installed on a highly stable nonmagnetic optical bench,the MSS-1A enables simultaneous high-precision measurements of both the Earth’s vector magnetic field and its scalar components.Its design integrates several state-of-the-art technologies,including arc-second-level thermal stability control,nonmagnetic thermal control for the optical bench,and ultra-high magnetic cleanliness control.These innovations effectively minimize magnetic interference originating from the satellite itself,thereby substantially improving the precision of geomagnetic field measurements and establishing a robust technical foundation for future magnetic survey satellite constellations. 展开更多
关键词 Macao Science Satellite-1 system design geomagnetic field observation optical bench magnetic cleanliness control
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Comprehensive analysis of noise in Macao Science Satellite-1 vector magnetometer data 被引量:1
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作者 SiShan Song Fan Yin +4 位作者 Qin Yan Hermann Lühr Chao Xiong Yi Jiang pengfei liu 《Earth and Planetary Physics》 2025年第3期532-540,共9页
The Macao Science Satellite-1(known as MSS-1)is the first scientific exploration satellite that was designed to measure the Earth's low latitude magnetic field at high resolution and with high precision by collect... The Macao Science Satellite-1(known as MSS-1)is the first scientific exploration satellite that was designed to measure the Earth's low latitude magnetic field at high resolution and with high precision by collecting data in a near-equatorial orbit.Magnetic field data from MSS-1's onboard Vector Fluxgate Magnetometer(VFM),collected at a sample rate of 50 Hz,allows us to detect and investigate sources of magnetic data contamination,from DC to relevant Nyquist frequency.Here we report two types of artificial disturbances in the VFM data.One is V-shaped events concentrated at night,with frequencies sweeping from the Nyquist frequency down to zero and back up.The other is 5-Hz events(ones that exhibit a distinct 5 Hz spectrum peak);these events are always accompanied by intervals of spiky signals,and are clearly related to the attitude control of the satellite.Our analyses show that VFM noise levels in daytime are systematically lower than in nighttime.The daily average noise levels exhibit a period of about 52 days.The V-shaped events are strongly correlated with higher VFM noise levels. 展开更多
关键词 Macao Science Satellite-1 Vector Fluxgate Magnetometer artificial disturbances noise features
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Inverting tidal velocity from geomagnetic satellite by nonlinear method 被引量:1
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作者 Yu Gu ZhengYong Ren +3 位作者 Yang Wu LiNan Xu pengfei liu Keke Zhang 《Earth and Planetary Physics》 2025年第3期607-613,共7页
This study presents an inversion method to recover the tidal flow velocity using tidal signals extracted from geomagnetic satellite dataset.By integrating the latest Earth conductivity profile and the Earth's magn... This study presents an inversion method to recover the tidal flow velocity using tidal signals extracted from geomagnetic satellite dataset.By integrating the latest Earth conductivity profile and the Earth's magnetic field model,the limited memory quasi-Newton method(L-BFGS)is used to directly invert seawater flow velocities.We used the radial component of the induced magnetic field as the observed data,constructed an L_(2)-norm-based data misfit term using theoretical response and observed data,and applied smoothness constraints to the ocean flow velocity.The results agree well with the widely used HAMTIDE model in low-and mid-latitude regions,which is attributed to Macao Science Satellite-1's(MSS-1)unique low-inclination orbit of full coverage in these areas.These findings underscore MSS-1's potential to advance research on tidal-induced magnetic fields and their applications in ocean dynamics studies. 展开更多
关键词 Macao Science Satellite-1 satellite magnetic data tidal velocity inversion
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The magnetic stripe signatures of the North Atlantic Ocean crust derived from Swarm and Macao Science Satellite-1 observations 被引量:1
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作者 pengfei liu Liang Yin +1 位作者 ShiDa Sun HongBo Yao 《Earth and Planetary Physics》 2025年第3期635-641,共7页
The Earth's crust,the outer shell of the Earth,consists of continental crust and oceanic crust.Oceanic crust is created at the mid-oceanic ridge,where it is magnetized in the ambient field of the Earth.As new mate... The Earth's crust,the outer shell of the Earth,consists of continental crust and oceanic crust.Oceanic crust is created at the mid-oceanic ridge,where it is magnetized in the ambient field of the Earth.As new material is extruded,the crust spreads outward,retaining its magnetization.The reversal of the polarity of the Earth's magnetic field over geologic time leads to a pattern of striped magnetic anomalies.In this study,we carry out a preliminary evaluation on how data from the Macao Science Satellite-1(MSS-1),which has a low orbital inclination,influences inversion models of the oceanic crustal magnetic field when combined with data from the Swarm mission.For our modeling we use an equivalent source method based on a cubed-sphere grid.Our model captures the broad magnetic structure over the North Atlantic Ocean and demonstrates that the trend of magnetic stripes is consistent with the age frame of the oceanic crust.The amplitude of the radial magnetic field at 450 km the North Atlantic Ocean ranges from–11 nT to+8 nT.The addition of MSS-1 observations to Swarm data generates results consistent with the overall magnetic stripe pattern.The lack of short-wavelength scale structure reveals the limitation of high-altitude satellites in portraying fine features and hence lower-altitude observations would be required to delineate a more detailed crustal signature.It is expected to obtain a finer structure of oceanic magnetic stripes by combining low-altitude CHAMP field data and east-west gradient data derived from MSS-1 in future work. 展开更多
关键词 ocean magnetic stripes lithospheric magnetic structure Macao Science Satellite-1
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熔盐热解法制备α相氮化硅粉体
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作者 杨帆 韩召 +1 位作者 刘鹏飞 李杰 《过程工程学报》 北大核心 2025年第10期1064-1074,共11页
随着氮化硅(Si_(3)N_(4))陶瓷在航空航天、电子器件和高温结构材料等应用领域的不断扩展,对高质量Si_(3)N_(4)粉体的需求日益增加。然而,传统硅亚胺热解法普遍存在结晶温度较高与晶须易形成的问题,严重影响Si_(3)N_(4)粉体质量与应用性... 随着氮化硅(Si_(3)N_(4))陶瓷在航空航天、电子器件和高温结构材料等应用领域的不断扩展,对高质量Si_(3)N_(4)粉体的需求日益增加。然而,传统硅亚胺热解法普遍存在结晶温度较高与晶须易形成的问题,严重影响Si_(3)N_(4)粉体质量与应用性能。本研究的创新点在于引入熔盐环境,通过降低硅亚胺[Si(NH)_(2)]的结晶与相变温度,实现了对Si_(3)N_(4)粉体粒径的控制,并避免了不规则晶须的生成。研究以Si(NH)_(2)为原料、氯化钠(NaCl)为熔盐介质,采用熔盐热解法制备了形貌规则的α-Si_(3)N_(4)粉体,并探究了热解温度和硅盐比对粉体物相组成、粒径分布及微观形貌的影响。结果表明,NaCl熔盐可显著降低Si(NH)_(2)结晶与相变温度,在1400℃保温2 h的条件下,Si(NH)_(2)可完全转化为结晶度高、形貌规则的Si_(3)N_(4)粉体,其中α-Si_(3)N_(4)含量达75.52wt%,平均粒径为905.40 nm。此外,随NaCl熔盐含量增加,粉体中α-Si_(3)N_(4)含量呈先降低后增加的变化趋势,但粉体粒径逐渐减小。该方法有效抑制Si(NH)_(2)热解过程中晶须的形成,降低α-Si_(3)N_(4)粉体的结晶温度。机理分析显示,在熔盐提供的液相环境中,Si(NH)_(2)通过溶解-析出机制促进α-Si_(3)N_(4)颗粒生长。此方法为制备高质量、形貌规则的Si_(3)N_(4)粉体提供了新思路,具有广泛的应用潜力。 展开更多
关键词 氮化硅 熔盐 粉体 硅亚胺
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Optimizing Geometric Parameters of Planing Vessels for Enhanced Hydrodynamic Performance
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作者 Rachid Tayeb Samir E.Belhenniche +3 位作者 Mustapha Belkadi Mohammed Adnan Rizk Omer Kemal Kinaci pengfei liu 《哈尔滨工程大学学报(英文版)》 2025年第5期970-983,共14页
The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull... The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull hydrodynamics.In this study,we conducted a numerical investigation using the Reynolds-averaged Navier-Stokes approach with overset grids to capture large motions at high speeds.This study aims to improve the hydrodynamic performances of planing hulls,specifically focusing on total resistance,trim,and sinkage.The initial Fridsma hull with a deadrise angle of 20°has been used for validation,demonstrating good agreement with measurements at different Froude numbers.Subsequently,new configurations based on the Fridsma hull have been designed by varying the deadrise angle,number of chines,and transverse steps.Our findings reveal a correlation between the deadrise angle,the number of chines,and the Froude number.As the deadrise angle increases,total resistance also increases.Additionally,a single chine yields superior results at higher Froude numbers,while multiple chines offer advantages at lower values.The introduction of transverse steps consistently increases total resistance,highlighting their role in improving planing hull performance.This research not only offers valuable insights into planing hull design but also leverages state-of-the-art numerical methods to advance the understanding of hydrodynamic behaviors at high ship speeds. 展开更多
关键词 Ship resistance Deadrise angle Overset grids Fridsma hull Planing hull Single chine Transverse steps
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Influence of Interspecies Interactions on Bacterial Community Assembly in the Active and Permafrost Layers on the Qinghai-Tibet Plateau
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作者 Hongfei Chi Xiufeng Yin +5 位作者 Xuefeng Zhang Jingyi Zhu Lin Zhao Yongcui Deng pengfei liu Yongqin liu 《Journal of Earth Science》 2025年第2期395-407,共13页
Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how woul... Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how would bacterial interaction influence the bacterial communities in permafrost of the Qinghai-Tibet Plateau(QTP)remains largely unknown.Here we collected paired soil samples from both the active and permafrost layers of two typical QTP permafrost regions in October 2020 for Tuotuohe River(TTH)and May 2022 for Aerjin(ARJ),and investigated the bacterial communities and the role of interactions in structuring the bacterial community and its assembly process through amplicon sequencing of the 16S rRNA gene.Our study revealed distinct bacterial communities,with significant differences in the relative abundances of Proteobacteria(P<0.05),Acidobacteriota(P<0.001),Bacteroidota(P<0.05),and Planctomycetota(P<0.001)between the active layer and the permafrost layer.More importantly,we found that interspecies interactions,including both positive and negative associations,were strongly correlated with bacterial alpha-diversity and played a significant role in community variation and assembly process.Our findings also showed that the community assembly in both the active and permafrost layers was primarily driven by homogeneous selection of deterministic processes,with interspecies interactions accounting for more than 58%and 63%of all assembly mechanisms,respectively.This is the first study to quantify the contribution of bacterial interactions in shaping the bacterial community and its assembly process in permafrost of QTP,highlighting the importance of considering interspecies interactions in future modeling efforts.Our work also emphasizes the necessity of including interspecies interactions in microbial process projections to reduce uncertainty. 展开更多
关键词 PERMAFROST the Qinghai-Tibet Plateau bacterial community Interspecies interaction community assembly process biogeology
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Dynamic modeling and simulation of irregular faults in axle box bearings of high-speed trains
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作者 Xiaohui GU Yajia WANG +2 位作者 pengfei liu Zechao liu Shaopu YANG 《Applied Mathematics and Mechanics(English Edition)》 2025年第10期1883-1902,共20页
Axle box bearings are critical components of high-speed trains.Localized defects,such as pitting and spalling,on raceways or rollers pose significant threats to the operational safety of railway vehicles.In this work,... Axle box bearings are critical components of high-speed trains.Localized defects,such as pitting and spalling,on raceways or rollers pose significant threats to the operational safety of railway vehicles.In this work,a novel bearing-flexible axle boxvehicle coupling model is established to explore the vibration characteristics of axle box bearings with irregular localized defects.First,based on the contact and kinematic relationship between rollers and raceways,the three-dimensional(3D)bearing force elements are analyzed and formulated.Second,the established model and a flexible axle box are integrated into the vehicle,and the responses of the normal and faulty bearings under the combined excitations of wheel roughness and track irregularities are simulated.Third,the simulation results are verified through a rolling-vibrating test bench for full-scale wheelsets of high-speed trains.The comparisons of the fault-induced repetitive transients in the time-domain and the fault characteristic frequencies in the envelope spectra demonstrate the efficiency of the proposed model.Finally,based on the flexible axle box model,a sensitivity analysis of the accelerometer placements to the bearing faults is carried out,and the optimal one is identified based on both the time-domain and frequency-domain signal-to-noise ratios(SNRs)for engineering applications. 展开更多
关键词 axle box bearing irregular fault track irregularity flexible axle box accelerometer placement selection
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Analysis of corrugation evolution characteristics based on scale-down tests-contact stick-slip perspective
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作者 Zhiqiang Wang pengfei liu 《Railway Sciences》 2025年第3期308-321,共14页
Purpose-Rail corrugation is still one of the unsolved challenges in the railway industry,and the abnormal vibration and high-frequency noise caused by it constitute serious adverse effects on the operating environment... Purpose-Rail corrugation is still one of the unsolved challenges in the railway industry,and the abnormal vibration and high-frequency noise caused by it constitute serious adverse effects on the operating environment.How to control corrugation has been an important research theme,and understanding corrugation evolution features is the necessary prerequisite.This study aims to investigate the specific evolution characteristics of corrugation from the contact stick-slip perspective.Design/methodology/approach-The formation and development processes of corrugation are analyzed by using a self-designed scale-down test device.Specifically,the contact stick-slip characteristics under different creepage conditions are analyzed and the formation mechanism of corrugation is summarized.On the basis of corrugation formation,the trend of corrugation development is further emphasized to completely describe the whole process of corrugation evolution.Findings-The results show that,under the determined vertical load condition,the contact interface appears the creep force-creepage negative slope phenomenon in the transverse direction.The cause of short-pitch corrugation on the rail wheel surface under the smaller angles of attack may be related to the inherent vibration frequency of the test device,and the cause of corrugation on the rail wheel surface under the larger angles of attack is mainly related to the stick-slip vibration induced by contact creep saturation.Originality/value-This research explores the evolution characteristics of corrugation by adopting a selfdesigned scale-down test device,and elucidates the mechanism of corrugation in detail. 展开更多
关键词 CORRUGATION Scale-down test Contact stick-slip Evolution process Angle of attack
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A cubed-sphere based method for global and regional modeling of the lithospheric magnetic field
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作者 Liang Yin JiaXuan Zhang +3 位作者 pengfei liu HongBo Yao Pan Zhang JinSong Du 《Earth and Planetary Physics》 2025年第3期622-634,共13页
The Earth's magnetic field,which has been extensively observed from ground to satellite altitudes over several decades,originates from multiple sources,such as the core dynamo,the conductive mantle,the magnetized ... The Earth's magnetic field,which has been extensively observed from ground to satellite altitudes over several decades,originates from multiple sources,such as the core dynamo,the conductive mantle,the magnetized lithosphere,and the space current systems.Modeling of the lithospheric contribution plays an important role in the geophysical studies and industrial applications.In this paper,we propose a new method for global and regional modeling of the lithospheric magnetic field based on the cubed-sphere.An equivalent dipole source method on a quasi-uniform cubed-sphere grid is employed in the forward modeling.The dipole directions are fixed according to a priori magnetization and the relative intensities are estimated by an inversion procedure of least-squares fitting with minimum model regularization.Several numerical tests are performed to validate the accuracy and efficiency of both forward modeling and inversion procedure.The proposed method is applied to the global and regional modeling based on the latest magnetic data from Swarm Alpha satellite and MSS-1 mission.The model results indicate that the proposed method works quite well for realistic satellite data and MSS-1 data is consistent with the Swarm data in terms of lithospheric field modeling. 展开更多
关键词 geomagnetic satellite lithospheric magnetic field cubed-sphere grid forward modeling INVERSION
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Emission fluxes of nitrous acid(HONO)from livestock and poultry wastes
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作者 Wenjin Zhang pengfei liu +11 位作者 Min Song Xuran Li Xiaoxi Zhao Yifei Song Di Tian Chenglong Zhang Yuanyuan Zhang Yangang Ren Chengtang liu Junfeng liu Yinchang Feng Yujing Mu 《Journal of Environmental Sciences》 2025年第10期466-473,共8页
Gaseous nitrous acid(HONO)is a critical contributor to daytime hydroxyl radical in the troposphere.Livestock farming has been recognized as an overlooked HONO source,but the lack of detailed flux measurements from liv... Gaseous nitrous acid(HONO)is a critical contributor to daytime hydroxyl radical in the troposphere.Livestock farming has been recognized as an overlooked HONO source,but the lack of detailed flux measurements from livestock and poultry wastes would cause uncertainties in modeling its environmental impacts.Here,based on field flux measurements and laboratory experiments,we observed substantial HONO emissions from the composting of swine feces and chicken manure in the warm season,which might be mainly attributed to nitrification process in livestock and poultry wastes.The HONO emission from chicken manure was found to bemuch higher than that from swine feces,and the higher NH3 emission but lower N2O and NO emissions fromchicken manurewere also observed.Considering that the interaction among these nitrogen species during nitrification process,the obviously lower HONO emission from swine feces was likely to be explained by the lack of the total ammonia nitrogen and H+donors in swine feces.Temperature is also a key factor that influences the HONO emission from livestock wastes.In addition,the total HONO emission from swine feces in Chinawas estimated to be approximately 107.7 Gg-N/yr according to the national swine amounts,which is comparable to the national soil HONO emissions,underscoring its non-negligible contribution to regional air quality.Therefore,effective emission control of HONO fromlivestock and poultry wastes should be carried out to further improve air quality in China. 展开更多
关键词 Nitrous acid(HONO) Flux measurements Livestock and poultry wastes Open-top dynamic chamber Air pollution
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Effects of nitrate(NO_(3)^(−))stress-induced exacerbated cadmium(Cd^(2+))toxicity on the inflammatory response,oxidative defense,and apoptosis in juvenile Japanese flounder(Paralichthys olivaceus)
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作者 Jiachen Yu Jie Lian +6 位作者 Yingying Wan Xiangyuan Li pengfei liu Qing Ji Suyue Zhou Nianhao Zheng Xingqiang Wang 《Journal of Environmental Sciences》 2025年第6期535-548,共14页
Due to the discharge of industrialwastewater,urban domestic sewage,and intensive marine aquaculture tailwater,nitrate(NO_(3)^(−))pollution has emerged as a significant issue in offshore waters.Nitrate pollution affect... Due to the discharge of industrialwastewater,urban domestic sewage,and intensive marine aquaculture tailwater,nitrate(NO_(3)^(−))pollution has emerged as a significant issue in offshore waters.Nitrate pollution affects aquatic life and may interact with other pollutants,leading to comprehensive toxicity.Cadmium(Cd^(2+))is the most widespread metal contaminant,adversely affecting aquatic life in the coastal waters of China.Despite this,few studies have focused on the synergistic toxicity of NO_(3)^(−)and Cd^(2+)in marine organisms.This study conducted a 30-day exposure experiment on marine Japanese flounder(Paralichthys olivaceus)to explore the synergistic toxicity of NO_(3)^(−)and Cd^(2+).Our results demonstrated that the exposure to Cd^(2+)alone induced slight histopathological changes in the liver.However,malformations such as hepatic vacuolar degeneration and sinusoid dilatationwere exacerbated under co-exposure.Moreover,co-exposure induced the downregulation of antioxidants and the upregulation of the product malonaldehyde(MDA)from lipid peroxidation,indicating potent oxidative stress in the liver.The increased mRNA expression of IL-8,TNF-α,and IL-1β,along with the decreased expression level of TGF-β,indicated a synergistic inflammatory response in the organisms.Furthermore,the co-exposure led to an abnormal expression of P53,caspase-3,caspase-9,Bcl-2,and Bax,and disturbed the apoptosis in the liver through TUNEL staining analysis.Overall,our results imply that co-exposure synergistically affects inflammation,redox status,and apoptosis in flounders.Therefore,the findings from this study provide valuable perspectives on the ecological risk assessment of marine teleosts co-exposure to NO_(3)^(−)and Cd^(2+). 展开更多
关键词 Nitrate pollution Cadmium Japanese flounder Oxidative defense APOPTOSIS
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Synergistically dissipating the local strain and restraining lattice oxygen escape by fine-tuning of microstructure enabling Ni-rich cathodes with superior cyclabilities
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作者 Fengxia Fan Ruixin Zheng +7 位作者 Chenrui Zeng Haoyang Xu Xinxiang Wang Guilei Tian Shuhan Wang Chuan Wang pengfei liu Chaozhu Shu 《Journal of Energy Chemistry》 2025年第6期24-34,I0002,共12页
LiNixCoyMn_(2)O_(2)(NCM,x≥0.8,x+y+z=1)cathodes have attracted much attention due to their high specific capacity and low cost.However,severe anisotropic volume changes and oxygen evolution induced capacity decay and ... LiNixCoyMn_(2)O_(2)(NCM,x≥0.8,x+y+z=1)cathodes have attracted much attention due to their high specific capacity and low cost.However,severe anisotropic volume changes and oxygen evolution induced capacity decay and insecurity have hindered their commercial application at scale.In order to overcome these challenges,a kind of tantalum(Ta)doped nickel-rich cathode with reduced size and significantly increased number of primary particles is prepared by combining mechanical fusion with high temperature co-calcination.The elaborately designed micro-morphology of small and uniform primary particles effectively eliminates the local strain accumulation caused by the random orientation of primary particles.Moreover,the uniform distribution of small primary particles stabilizes the spherical secondary particles,thus effectively inhibiting the formation and extension of microcracks.In addition,the formed strong Ta-O bonds restrain the release of lattice oxygen,which greatly increases the structural stability and safety of NCM materials.Therefore,the cathode material with the designed primary particle morphology shows superior electrochemical performance.The 1 mol%Ta-modified cathode(defined as1%Ta-NCM)shows a capacity retention of 97.5%after 200 cycles at 1 C and a rate performance of 137.3 mAh g^(-1)at 5 C.This work presents promising approach to improve the structural stability and safety of nickel-rich NCM. 展开更多
关键词 Ni-rich cathodes MICROCRACKS Lattice oxygen Structural stability Lithium-ion batteries
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选矿浮选分段加药理论与实践
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作者 庹意龙 刘鹏飞 厉生杰 《新疆钢铁》 2025年第2期18-20,共3页
选矿浮选作业是通过选矿药剂将有用矿物从原矿中浮选出来的过程,传统的浮选加药方式是单次足量加药,经多次富集得到最终产品。甘肃某选厂原矿品位逐年下降,采用一次加药的方式,精矿品位无法达到指标要求,易使氧化镁含量超标。通过采用... 选矿浮选作业是通过选矿药剂将有用矿物从原矿中浮选出来的过程,传统的浮选加药方式是单次足量加药,经多次富集得到最终产品。甘肃某选厂原矿品位逐年下降,采用一次加药的方式,精矿品位无法达到指标要求,易使氧化镁含量超标。通过采用分段加药,实现了精选区富集效果提升,最终精矿品位达到指标要求,氧化镁含量也降低到要求水平。 展开更多
关键词 加药方式 一次加药 分段加药 富集 精选区
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Preface to the Special Issue of Initial Scientific Results of MSS-1
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作者 Keke Zhang pengfei liu YongXin Pan 《Earth and Planetary Physics》 2025年第3期475-478,共4页
The scientific research of geomagnetism has been largely driven by new geomagnetic data that are available to scientists.Macao Science Satellite-1(MSS-1)was successfully launched on 21st May 2023 into a near-circular ... The scientific research of geomagnetism has been largely driven by new geomagnetic data that are available to scientists.Macao Science Satellite-1(MSS-1)was successfully launched on 21st May 2023 into a near-circular orbit of altitude of about 450 km with a low inclination of 41°.After careful evaluation and calibration(7^(th)June 2023 to 31^(st)July 2024),the data of MSS-1 were released to the international scientific community on 1 August 2024,providing the highly accurate data of global geomagnetic field with an unprecedented local-time coverage to the community.This special issue of Initial Scientific Results of MSS-1,primarily driven by the new MSS-1 data,contains 27 research articles ranging from the MSS-1 design,satellite data analysis,outer core dynamics,mantle induction,lithospheric field modeling,ocean induced magnetic field,ionosphere and magnetosphere currents,to solar activities. 展开更多
关键词 GEOMAGNETISM GEODYNAMO MAGNETOMETERS Macao Science Satellite-1
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Predicting Postoperative Circulatory Complications in Older Patients: A Machine Learning Approach
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作者 Xiaoyun Hu Weixuan Sheng +5 位作者 Kang Yu Jietai Duo pengfei liu Yawei Li Dongxin Wang Huihui Miao 《Biomedical and Environmental Sciences》 2025年第3期328-340,共13页
Objective This study examines utilizes the advantages of machine learning algorithms to discern key determinants in prognosticate postoperative circulatory complications(PCCs)for older patients.Methods This secondary ... Objective This study examines utilizes the advantages of machine learning algorithms to discern key determinants in prognosticate postoperative circulatory complications(PCCs)for older patients.Methods This secondary analysis of data from a randomized controlled trial involved 1,720 elderly participants in five tertiary hospitals in Beijing,China.Participants aged 60–90 years undergoing major non-cardiac surgery under general anesthesia.The primary outcome metric of the study was the occurrence of PCCs,according to the European Society of Cardiology and the European Society of Anaesthesiology diagnostic criteria.The analysis metrics contained 67 candidate variables,including baseline characteristics,laboratory tests,and scale assessments.Results Our feature selection process identified key variables that significantly impact patient outcomes,including the duration of ICU stay,surgery,and anesthesia;APACHE-Ⅱscore;intraoperative average heart rate and blood loss;cumulative opioid use during surgery;patient age;VAS-Move-Median score on the 1st to 3rd day;Charlson comorbidity score;volumes of intraoperative plasma,crystalloid,and colloid fluids;cumulative red blood cell transfusion during surgery;and endotracheal intubation duration.Notably,our Random Forest model demonstrated exceptional performance with an accuracy of 0.9872.Conclusion We have developed and validated an algorithm for predicting PCCs in elderly patients by identifying key risk factors. 展开更多
关键词 Postoperative cardiovascular complications Older patients Random forest
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Machine learning facilitates the development of interconnecting layers for perovskite/silicon heterojunction tandem solar cells with proof-of-concept efficiency>38%
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作者 Xuejiao Wang Guanlan Chen +12 位作者 Ying liu Guangyi Wang Wei Han Jin Wang pengfei liu Jilei Wang Shaojuan Bao Bo Yu Ying liu Xinliang Chen Shengzhi Xu Ying Zhao Xiaodan Zhang 《Journal of Semiconductors》 2025年第11期77-86,共10页
As the development of single-junction solar cells reaches a bottleneck,tandem solar cells have emerged as a critical pathway to further enhance power conversion efficiency.Among them,monolithic perovskite/silicon hete... As the development of single-junction solar cells reaches a bottleneck,tandem solar cells have emerged as a critical pathway to further enhance power conversion efficiency.Among them,monolithic perovskite/silicon heterojunction tandem solar cells are currently the fastest-growing technology,achieving the highest efficiencies at relatively low costs.The intercon-necting layer,which connects the two sub-cells,plays a crucial role in tandem cell performance.It collects electrons and holes from the respective sub-cells and facilitates recombination and tunneling at the interface.Therefore,the properties of the inter-connecting layer are pivotal to the overall device performance.In this work,we applied statistical analysis and machine learn-ing algorithms to systematically analyze the interconnecting layer.A comprehensive dataset on interconnecting layer parame-ters was established,and predictive modeling was performed using Lasso linear regression,random forest,and multilayer per-ceptron(a type of neural network).The analysis revealed key feature importance for experimental parameters,providing valu-able insights into the application of interconnecting layers in perovskite/silicon heterojunction tandem solar cells.The final opti-mized interconnecting layer can achieve a proof-of-concept efficiency of 38.17%,providing guidance and direction for the devel-opment of monolithic perovskite/silicon tandem solar cells. 展开更多
关键词 perovskite/silicon heterojunction tandem solar cells interconnecting layer machine learning
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