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A novel model of the carbon cycle in the Cambrian ocean

Science China earth Sciences 2024年第6期67卷 1759-1778页

作者： Huajian WANG Shuichang ZHANG Xiaomei WANG Jin SU Yuntao YE Yuke LIU key laboratory of Petroleum Geochemistry Research Institute of Petroleum Exploration and DevelopmentChina National Petroleum CorporationBeijing 100083China key laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China

The classic model of the carbon cycle suggests that the extensive burial of ^(12)C-enriched organic carbon leads to a positive carbon isotope(δ^(13)C)excursion(CIE),while massive oxidation of organic carbon results in a negative CIE.However,global events such as the BAsal Cambrian Carbon isotope Excursion(BACE)and the Steptoean Positive Carbon Isotope Excursion(SPICE)are global negative and positive δ^(13)C excursions,respectively,and they also exhibit significant organic carbon burial anomalies,displaying decoupling between carbon isotope anomalies and organic carbon burial.Based on the analyses of the Cambrian carbon cycle and paleoceanographic evolution records from well Tadong2 in the Tarim Basin,we propose a novel model of the carbon cycle in the Cambrian ocean that incorporates oceanic dissolved organic carbon(DOC).Our findings are as follows.(1)The Cambrian ocean maintained substantial DOC reservoirs,which were regulated by ocean currents and paleo-redox conditions and exerted significant influence on the oceanic carbon cycle.(2)The oxidation of the oceanic DOC reservoirs during the early Cambrian led to the BACE and the Asian Phenomenon of the Cambrian petroleum systems,while the expansion of the oceanic DOC reservoirs during the SPICE resulted in a global positive δ^(13)C excursion and the absence of significant organic carbon burial.(3)The deep-basin sedimentary environment in the eastern depression of the Tarim Basin may have fostered the development of organic-rich black shales during the Furongian Series,corresponding to organic carbon burial during the SPICE and representing potential prospects for ultra-deep oil and gas exploration.Future research should focus on the formation mechanism,reserve scale,and influencing factors of the oceanic DOC reservoirs,as well as their resource and environmental effects.It is expected that new breakthroughs will be made in the fields of earth system science and oil and gas exploration.

关键词： Carbon isotope Organic carbon BACE SPICE Dissolved organic carbon Climate change Black shale

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Pillar effect induced by ultrahigh phosphorous/nitrogen doping enables graphene/MXene film with excellent cycling stability for alkali metal ion storage

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Journal of Energy Chemistry 2024年第6期93卷 146-156,I0004页

作者： Meng Qin Yiwei Yao Junjie Mao Chi Chen Kai Zhu Guiling Wang Dianxue Cao Jun Yan key laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001HeilongjiangChina Xiamen key laboratory of Rare earth Photoelectric Functional Materials and Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021FujianChina

Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and long ion transfer distance.Herein,this paper aims to address the issue by introducing MXene through a simple and scalable method for assembling graphene and realizing ultrahigh P doping content.The findings reveal that MXene and P-C bonds have a "pillar effect" on the structure of graphene,and the P-C bond plays a primary role.In addition,N/P co-doping introduces abundant defects,providing more active sites for K^(+) storage and facilitating K^(+) adsorption.As expected,the developed ultrahigh phosphorous/nitrogen co-doped flexible reduced graphene oxide/MXene(NPrGM) electrode exhibits remarkable reversible discharge capacity(554 mA hg^(-1) at 0.05 A g^(-1)),impressive rate capability(178 mA h g^(-1) at 2 A g^(-1)),and robust cyclic stability(0.0005% decay per cycle after 10,000 cycles at 2 A g^(-1)).Furthermore,the assembled activated carbon‖NPrGM potassium-ion hybrid capacitor(PIHC) can deliver an impressive energy density of 131 W h kg^(-1) and stable cycling performance with 98.1% capacitance retention after5000 cycles at 1 A g^(-1).Such a new strategy will effectively promote the practical application of graphene materials in PIBs/PIHCs and open new avenues for the scalable development of flexible films based on two-dimensional materials for potential applications in energy storage,thermal interface,and electromagnetic shielding.

关键词： Graphene MXene Phosphorous doping Pillar effect Potassium-ion batteries

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A hybrid WUDT-NAFnet for simultaneous source data deblending

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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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Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China earth Sciences 2024年第5期67卷 1436-1458页

作者： Qing GONG Ming-Xing LING Wang ZHENG State key laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)eruptions.However,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic activities.Mercury stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic record.To date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the Phanerozoic.However,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of volcanism.With a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

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Simultaneously enhancing coercivity and remanence of hot-deformed Nd-Fe-B magnets by flake copper powder assisted DyF3 interflake addition

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Journal of Rare earths 2024年第7期42卷 1282-1288页

作者： Yikuan Hu Jiajie Li Shengyu Sun Shuwei Zhong Munan Yang Xiaoqiang Yu Sajjad Ur Rehman Xi Yu Jiangxi key laboratory for Rare earth Magnetic Materials and Devices College of Rare EarthsJiangxi University of Science and Technology National Rare earth Functional Materials Innovation Center Ganzhou Fortune Electronic Ltd.

It is still a challenge to simultaneously enhance coercivity(Hcj) and remanence（Jr） of hot-deformed NdFe-B magnet due to the coercivity-remanence trade-off dilemma.Here,we achieved this balance between Hcjand Jrby flake Cu powder assisted DyF3interflake addition.The Hcjincreases from 1218 to1496 kA/m and Jrincreases from 1.32 to 1.34 T compared with the original magnet.Results show that the width of coarse grain layers reduces because of the introduction of flake Cu,which increases the contact areas of the adjacent grains at ribbon interfaces and suppresses the excessive growth of grains.The stronger degree of texture and higher density compared with the original magnet should take the responsibility for the increase of Jr.Additionally,the aggregation regions of rare earth rich（RE-rich） phase reduce and the betterment of the microstructure is another reason for the enhancement of Jrin the flake Cu aided DyF3hot-deformed magnet.This strategy of using flake powder additives provides a promising method for optimizing microstructure and enhancing magnetic properties of hot-deformed Nd-Fe-B magnets.

关键词： Flake powder Hot-deformed magnet Interflake addition Nd-Fe-B Rare earths Remanence

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Synthesis and optical properties of highly efficient Na3KMg7（PO4）6:Eu2+ blue phosphor for full-spectrum white-light-emitting diodes:The role of Li2CO3 flux

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Journal of Rare earths 2024年第7期42卷 1217-1223页

作者： Zihao Wang Sisi Liang Chenyang Zhan Kunyuan Xu Jie Hu Dejian Chen Liping Song Haomiao Zhu School of Physics and Materials Science Nanchang University Ganjiang Innovation Academy Chinese Academy of Sciences CAS key laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of Sciences Xiamen key laboratory of Rare earth Photoelectric Functional Materials Xiamen Research Center of Rare Earth MaterialsHaixi InstituteChinese Academy of Sciences

Full-spectrum phosphor-converted white-light-emitting diodes（pc-WLED） are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na3KMg7（PO4）6:Eu2+phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li2CO3as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV（400 nm） diode chip excitation.The practical Eu2+concentration is also enhanced by using Li2CO3as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL the rmal stability,na mely retains 94% integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu2+blue,Sr2SiO4:Eu2+green,CaAlSiN3:Eu2+red phosphors,and a400 nm NUV diode chip.It shows a high color rendering index of Ra=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu2+is a promising blue phosphor for fullspectrum WLED based on NUV diode chips.

关键词： Blue phosphor Eu2+ Full-spectrum white LEDs Na3KMg7(PO4)6 Rare earths

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Two thin middle-crust low-velocity zones imaged in the Chuan-Dian region of southeastern Tibetan Plateau and their tectonic implications

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Science China earth Sciences 2024年第5期67卷 1675-1686页

作者： Long LI Xin WANG Guangbing HOU Yuan LING Yinshuang AI key laboratory of earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for earth Science Chinese Academy of SciencesBeijing 100029China

Intracrustal low-velocity zones(LVZs)indicate a mechanically weak crust and are widely observed in the southeast margin of the Tibetan Plateau.However,their spatial distributions and formation mechanisms remain controversial.To investigate their distribution and detailed morphology of the LVZs in the southeastern Tibetan Plateau,here we used teleseismic events and continuous waveform data recorded by 40 broadband seismic stations newly deployed in the Sichuan-Yunnan region from December 2018 to October 2020.A total of 12,924 high-quality P-wave receiver functions and 5–40 s fundamental Rayleigh surface wave phase velocity dispersion curves from ambient noise cross-correlation functions were obtained.The Swave velocity model at a depth interval of 0–100 km in the study area was inverted by using the trans-dimensional Markov chain Monte Carlo strategy to jointly invert the complementary data of the receiver function waveform and Rayleigh surface wave phase velocity dispersion.Our results show that there are two separate LVZs(~3.5 km/s)surrounding the rigid Daliangshan subblock at crustal depths of approximately 30–40 km,providing new constraints on the geometry of the LVZs in our study region.The two LVZs obtained in this study may represent the middle crustal flow channels,through which the material in the center of the Tibetan Plateau extrudes to its southeast margin.Blocked by the rigid Sichuan Basin and the spindle-like Daliangshan subblock,the material continues to flow southward through the mechanically weak middle crustal channels surrounding the Daliangshan subblock.In addition,the existence of thin LVZs in the middle crust plays an important role in understanding the decoupling between the upper and lower crust in the study area.It also provides new constraint on the complex tectonic deformation process of the southeastern margin of the Tibetan Plateau caused by the collision and compression of the Indian and the Eurasian plates.

关键词： Southeastern Tibetan Plateau Joint inversion Intracrustal low-velocity zone Mid-crustal channel flow

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Degradation of Rhodamine B by MnFe-LDH/PMS/O_(3) three-phase catalytic system: performance, mechanism and ecotoxicity studies

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 111-127页

作者： Ying Han Ying Yang Weibao Liu Yilong Hou Ce Wang Jiangwei Shang Xiuwen Cheng key laboratory of Pollutant Chemistry and Environmental Treatment College of Chemistry and Environmental ScienceYili Normal UniversityYining 835000China key laboratory for Environmental Pollution Prediction and Control of Gansu Province College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

This study developed a novel MnFe-LDH/PMS/O3 three-phase catalytic system to degrade the organic dye RhB, which was used to address the drawbacks of persulfate oxidation and ozonation techniques. The structure, ionic and elemental composition, specific surface area, and magnetic properties of the LDHs were investigated using a variety of physicochemical characterization tools. The results showed that MnFe-LDH had a large specific surface area, a rich crystalline phase composition, and a functional group structure. The RhB degradation rate of MnFe-LDH/PMS/O3 was 0.34 min−1, which was much higher than that of other comparative systems. RhB could be completely degraded in 10 min after optimization and had a significant effect on TOC removal. The system was found to be effective over a wide pH range. Common anions were largely unaffected and humic acid acted as an inhibitor. At the same time, the system had generally effective degradation performance for different dyes. Combined with quenching experiments and EPR, it was found that SO4•−, •OH, O_(2)•−, and 1O_(2) all participated in the reaction, and •OH contributed more. The degradation pathway of RhB was derived by LC-MS, and the T.E.S.T. evaluation found that the toxicity of the intermediate product was significantly reduced. Finally, the stability and availability of LDHs were verified using cycling experiments and metal ion leaching. This work provides a theoretical basis and data support for the synergistic catalysis of PMS/O3 and the deep treatment of dye wastewater.

关键词： Rhodamine B Layered double hydroxides Peroxymonosulfate Ozonation

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A universal multifunctional dual cation doping strategy towards stabilized ultra-high nickel cobalt-free lithium layered oxide cathode

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Journal of Energy Chemistry 2024年第8期95卷 296-305页

作者： Yabin Shen Dongming Yin Limin Wang Gang Huang Yong Cheng Henan Institute of Advanced Technology Zhengzhou University State key laboratory of Rare earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries（LIBs） because of their relatively high capacity and low cost.Nevertheless,the high nickel content would induce bulk structure degradation and interfacial environment deterioration,and the absence of Co element reduces the lithium diffusion kinetics,severely limiting the performance liberation of this kind of cathodes.Herein,a multifunctional Ti/Zr dual cation co-doping strategy has been employed to improve the lithium storage performance of LiNi0.9Mn0.1O2（NM91） cathode.On the one hand,the Ti/Zr co-doping weakens the Li+/Ni2+mixing through magnetic interactions due to the inexistence of unpaired electrons for Ti4+and Zr4+,increasing the lithium diffusion rate and suppressing the harmful coexistence of H1 and H2 phases.On the other hand,they enhance the lattice oxygen stability because of the strong Ti-O and Zr-O bonds,inhibiting the undesired H3 phase transition and lattice oxygen loss,improving the bulk structure and cathode-electrolyte interface stability.As a result,the Ti/Zr co-doped NM91（NMTZ） exhibits a 91.2% capacity retention rate after 100 cycles,while that of NM91 is only82.9%.Also,the NMTZ displays better rate performance than NM91 with output capacities of 115 and93 mA h g-1at a high current density of 5 C,respectively.Moreover,the designed NMTZ could enable the full battery to deliver an energy density up to 263 W h kg-1,making the ultra-high nickel cobaltfree lithium layered oxide cathode closer to practical applications.

关键词： Lattice oxygen stability Li+/Ni2+ mixing Lithium-ion battery Ti/Zr co-doping Ultra-high nickel cobalt-free cathode

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Coupled Surface Process and Orographic Precipitation Model for the Landscape Evolution of the Himalayas

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Journal of earth Science 2024年第3期35卷 1063-1068页

作者： Yuqiang Li Xiaoping Yuan Hubei key laboratory of Critical Zone Evolution School of Earth SciencesChina University of GeosciencesWuhan 430074China

0 INTRODUCTION The landscape evolution of mountain belts links rock uplift caused by tectonic deformation in the lithosphere to fluvial erosion and deposition driven by climatic precipitation in the atmosphere.The Himalayas,one of the most typical mountain belts in the world,are undergoing the strong collision of the Indian and Eurasian plates and the strong South Asian monsoon precipitation(Figure 1a).It is a natural laboratory to research the evolution mechanisms of orogenic growth involving tectonic and climatic processes.In addition,it is a good prototype to advance and verify many research methods in multiple disciplines.The Indian-Eurasian collision initiated since the Early Paleogene(ca.50 Ma)based on geological,stratigraphic,and palaeomagnetic records(Ding et al.,2022;van Hinsbergen et al.,2012),causing an early slow topographic change in the Himalayas until the Neogene(ca.23 Ma)(Ding et al.,2022).

关键词： Eurasian climatic tectonic

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