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Zircon Zr isotope fractionation during crustal anatexis

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Science China Earth Sciences 2024年第8期67卷 2495-2506页

作者： Erlin ZHU Qiongxia XIA Zhaoya LI Renxu CHEN James VAN ORMAN School of Earth and space Sciences University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Lithospheric and Environmental Coevolution Hefei 230026China Frontiers Science center for Planetary Exploration and Emerging Technologies University of Science and Technology of ChinaHefei 230026China Department of Earth Environmental and Planetary SciencesCase Western Reserve UniversityCleveland OH 44106USA

Zirconium is one of high field strength elements but its isotope behavior during geochemical processes is still uncertain because of the limited *** Zr isotopes in magmatic rocks are often used to trace the evolution of magmas through fractional crystallization,it is intriguing how highly heterogeneous Zr isotopes were produced by the growth of zircon during crustal *** address this issue by in-situ zircon Zr isotope analyses of migmatites from two high-temperature metamorphic terranes in the South Lhasa zone and the North Dabie zone,respectively,in *** results show highly variable δ^(94)Zr values from-0.30‰ to +0.81‰ and from-0.58‰ to +0.49‰,*** addition to the relict zircon of magmatic origin,two types of newly-grown zircons were identified in terms of their occurrences,trace elements and δ^(94)Zr *** peritectic zircon,mainly occurring in the in-situ leucosomes,exhibits the highest Nb-Ta-Hf-U contents and variably higher δ^(94)Zr values than those of the relict *** anatectic zircon,mainly occurring in the leucocratic veins,shows higher Nb-Ta-Hf-U contents than and similar δ^(94)Zr values to those of the relict *** calculations demonstrate that the variable Zr isotope compositions of newly-grown zircons would result from decoupled release of Zr from zircon and non-zircon *** Zr supply of the peritectic zircon is mainly derived from the decomposition of Zr-bearing minerals in the in-situ anatectic melt(the non-zircon effect),whereas the Zr supply of the anatectic zircon is mainly from the dissolution of pre-existing zircons in the evolved melt(the zircon effect).The significant Zr isotope variations in the migmatites well illustrate the generation,migration and accumulation of the anatectic melts during the partial ***,Zr isotopes can be used as a powerful means for distinguishing between the peritectic and anatectic zircons during crustal anatexis.

关键词： Zr isotopes Zircon effect Non-zircon effect Migmatite Crustal anatexis

General formalism for dirty extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： Ye Jiang Wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy and space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity are important applications of extreme-mass-ratio inspirals(EMRIs).There is still a challenge to efficiently describe various“dirty”impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study,we find the inherent linearity of the asymptotic solution of the inhomogeneous Teukolsky *** the basis of this property,we completely decouple the factors of the perturber and the background spacetime in the energy fluxes and *** the new decoupling form,the waveforms of EMRIs with non-geodesic motion in Kerr spacetime can be conveniently *** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky equation extreme-mass-ratio inspirals

Time Transfer in a 1839-km Telecommunication Fiber Link Demonstrating a Picosecond-Scale Stability

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Chinese Physics Letters 2024年第6期41卷 49-53页

作者：郭新兴侯丙安刘博杨凡孔维成刘涛董瑞芳张首刚 Key Laboratory of Time and Frequency Primary Standards National Time Service CenterChinese Academy of SciencesXi’an 710600China School of Astronomy and space Science University of Chinese Academy of SciencesBeijing 100049China Sichuan Taifu Ground Beidou Technology Co. LtdChengdu 610093China Hefei National Laboratory Hefei 230088China

An implementation of high-precision time transfer over a 1839-km field fiber loop back link between two provincial capitals of China,Xi’an and Taiyuan,is *** transfer stabilities of 6.5 ps at averaging time of 1 s and 4.6 ps at 40000 s were *** uncertainty for the time transfer system was evaluated,showing a budget of 56.2 *** results stand for a significant milestone in achieving high-precision time transfer over a field fiber link spanning thousands of kilometers,signifying a record-breaking achievement for the real-field time transfer in both stability and distance,which paves the way for constructing the nationwide high-precision time service via fiber network.

关键词： fiber nationwide Link

The existence of saturated vapors in the deep source region of 2017Pohang earthquake evidenced from seismic tomography

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Earth and Planetary Physics 2024年第5期8卷 811-821页

作者： JiaWei Qian HaiJiang Zhang Lei Guo Uzonna Okenna Anyiam Changsoo Cho Kang Hyeun Ji HaoRan Ma School of Carbon Neutrality Science and Engineering Anhui University of Science and Technology College of Oceanography Hohai University Laboratory of Seismology and Physics of Earth's Interior School of Earth and Space Sciences University of Science and Technology of China Hebei Earthquake Agency Geological and Environmental Science Hope College Earthquake Research center Korea Institute of Geoscience and Mineral Resources

Geothermal resources are a promising approach to clean renewable energy; 90% of them are deep reservoirs of hot dry rock that require hydraulic fracturing to create a network of connections among wells to enable efficient heat exchange, known as an Enhanced Geothermal System（EGS）. The Pohang EGS project in south Korea led to a devasting Mw5.5 earthquake, triggered by the reservoir's EGS stimulation, the largest earthquake known to have been induced by EGS development. Detailed investigations have been conducted to understand the cause of the Pohang earthquake; the conclusion has been that overpressurized injected fluids migrated into an unknown fault triggering this large earthquake. Detailed velocity images for the source zone of the 2017 Pohang earthquake,which could be helpful for further understanding its inducing mechanism, are unavailable. However, we have assembled detailed aftershock data recorded by 41 local stations installed within about three months after the Mw5.5 Pohang earthquake, and have then applied the Vp/Vsmodel's consistency-constrained double-difference seismic tomography method to determine the high-resolution three-dimensional Vp（compressional wave velocity）, Vs（shear wave velocity）, and Vp/Vsmodels of the source region that we report here,as well as earthquake locations within the source region. The velocity images reveal that the deep source area of the 2017 Pohang earthquake is dominated by low Vp, high Vs, and low Vp/Vsanomalies, a pattern that can be caused by overpressurized vapors due to high temperatures at these depths. Based on aftershock locations and velocity features, our studies support the conclusion that the 2017Pohang earthquake was triggered by injected EGS fluids that migrated into a blind fault.

关键词： Pohang earthquake tomoDDMC low Vp/Vs saturated vapors EGS

Measurement of atmospheric non-reciprocity effects for satellite-based two-way time-frequency transfer

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Photonics Research 2024年第6期12卷 1274-1282页

作者： TING ZENG QI SHEN YUAN CAO JIAN-YU GUAN MENG-ZHE LIAN JIN-JIAN HAN LEI HOU JIAN LU XIN-XIN PENG MIN LI WEI-YUE LIU JIN-CAI WU YONG WANG JUAN YIN JI-GANG REN HAI-FENG JIANG QIANG ZHANG CHENG-ZHI PENG JIAN-WEI PAN Hefei National Research center for Physical Sciences at the Microscale and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Shanghai Research center for Quantum Science and CAS center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaShanghai 201315China Hefei National Laboratory University of Science and Technology of ChinaHefei 230094China Faculty of Information Science and Engineering Ningbo UniversityNingbo 315211China Key Laboratory of space Active Opto-Electronic Technology Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

Future optical clock networks will require high-precision optical time-frequency transfer between satellites and ground ***,due to atmospheric turbulence,satellite motion and time delay between the satellite–ground transmission links will cause spatial and temporal variations,respectively,resulting in the breakdown of the time-of-flight reciprocity on which optical two-way time-frequency transfer is ***,we experimentally simulate the atmospheric effects by two-way spatio-temporally separated links between two stationary terminals located 113 km apart and measure the effects for optical two-way time-frequency *** experiment shows that the effect on the link instability is less than 2.3×10^(−19) at 10,000 *** indicates that when the link instability of satellite-ground optical time-frequency transfer is on the order of 10^(−19),it is not necessary to consider the atmospheric non-reciprocity effects.

关键词： breakdown transfer satellite

Systematic study of cluster radioactivity within the generalized liquid drop model

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Chinese Physics C 2024年第6期48卷 118-129页

作者：邓军刚程俊皓包小军张鸿飞 College of Science China Three Gorges UniversityYichang 443002China center for Astronomy and space Sciences China Three Gorges UniversityYichang 443002China Department of Physics National University of Defense TechnologyChangsha 410073China Department of Physics Collaborative Innovation Center for Quantum Effectsand Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationHunan Normal UniversityChangsha 410081China School of Physics Xi'an Jiaotong UniversityXi'an 710049China

Cluster radioactivity is studied within the generalized liquid drop model(GLDM),in which the shell correction energy,pairing energy,and cluster preformation factor are *** calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after considering these physical *** addition,the systematic trend of the cluster preformation factors is discussed in terms of the N_(p)N_(n)scheme to study the influence of the valence proton-neutron interaction and shell effect on cluster *** is found that log10Pcis linearly related to N_(p)N_(n).This is in agreement with a recent study[*** et al.,***.C 108,014325(2023)],in which log10Pc,obtained using different theoretical models and treatment methods than those used in this study,also had a linear relationship with N_(p)N_(n).Combined with the work by Qi et al.,this study suggests that the linear relationship between log10Pcand N_(p)N_(n)is model-independent and both the shell effect and valence proton-neutron interaction play essential roles in cluster *** analytical formula is proposed to calculate the cluster preformation factor based on the N_(p)N_(n)*** addition,the cluster preformation factors and the cluster radioactivity half-lives of some heavy nuclei are predicted,which can provide a reference for future experiments.

关键词： cluster radioactivity cluster preformation factor shell effect generalized liquid drop model

Discovery of a geomorphological analog to Martian araneiforms in the Qaidam Basin, Tibetan Plateau

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中国科学技术大学学报 2024年第5期54卷 1-9,I0006页

作者： Shengxing Zhang Yiliang Li Wei Leng Laboratory of Seismology and Physics of Earth’s Interior School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Department of Earth Sciences The University of Hong KongHong Kong 999077China CAS center for Excellence in Comparative Planetology Hefei 230026China

Araneiforms are spider-like ground patterns that are widespread in the southern polar regions of Mars.A gas erosion process driven by the seasonal sublimation of CO_(2) ice was proposed as an explanation for their formation,which cannot occur on Earth due to the high climatic *** this study,we propose an alternative mechanism that attrib-utes the araneiform formation to the erosion of upwelling salt water from the subsurface,relying on the identification of the first terrestrial analog found in a playa of the Qaidam Basin on the northern Tibetan *** analysis indicates that the structures in the Qaidam Basin have fractal features comparable to araneiforms on Mars.A numerical model is developed to investigate the araneiform formation driven by the water-diffusion *** simulation res-ults indicate that the water-diffusion process,under varying ground conditions,may be responsible for the diverse aranei-form morphologies observed on both Earth and *** numerical simulations also demonstrate that the orientations of the saltwater diffusion networks are controlled by pre-existing polygonal cracks,which is consistent with observations of araneiforms on Mars and *** study thus suggests that a saltwater-related origin of the araneiform is possible and has significant implications for water searches on Mars.

关键词： araneiform landform subsurface water Qaidam Basin Mars analog fractal simulations

Stress tensor determination by modified hydraulic tests on pre-existing fractures:Method and stress constraints

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1637-1648页

作者： Guiyun Gao Chenghu Wang Ke Gao National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Beijing Engineering Research center of Earthquake Observation Beijing100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing100085China Department of Earth and space Sciences Southern University of Science and TechnologyShenzhen518055China

The hydraulic testing of pre-existing fractures(HTPF)is one of the most promising in situ stress measurement methods,particularly for three-dimensional stress tensor ***,the stress tensor determination based on the HTPF method requires at least six tests or a minimum of 14-15 tests(under different conditions)for reliable *** this study,we modified the HTPF method by considering the shear stress on each pre-existing fracture,which increased the number of equations for the stress tensor determination and decreased the number of tests *** shear stresses were attributed to different fractures by random sampling;therefore,the stress tensors were obtained by searching for the optimal solution using the least squares criterion based on the Monte Carlo ***,we constrained the stress tensor based on the tensile strength criterion,compressive strength criterion,and vertical stress *** inverted stress tensors were presented and analyzed based on the tensorial nature of the stress using the Euclidean mean stress *** stress-measurement campaigns in Weifang(Shandong Province,China)and Mercantour road tunnel(France)were implemented to highlight the validity and efficiency of the modified HTPF(M-HTPF)*** results showed that the M-HTPF method can be applied for stress tensor inversion using only three to four tests on pre-existing fractures,neglecting the stress *** inversion results were confined to relatively small distribution dispersions and were significantly reliable and stable due to the shear stresses on the fractures and the stress constraints *** M-HTPF method is highly feasible and efficient for complete stress tensor determination in a single borehole.

关键词： Stress tensor Hydraulic tests on pre-existing fractures Mean stress Stress constraint Hydraulic fracturing

A particle-resolved heat-particle-fluid coupling model by DEM-IMB-LBM

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2267-2281页

作者： Ming Xia Jinlong Fu Y.T.Feng Fengqiang Gong Jin Yu Hunan Key Laboratory of Geomechanics and Engineering Safety Xiangtan UniversityXiangtan411105China Zienkiewicz Institute for Modelling Data and AISwansea UniversitySwanseaSA18EPUK School of Civil Engineering Southeast UniversityNanjing211189China Fujian Research center for Tunneling and Urban Underground space Engineering Huaqiao UniversityXiamen361021China

Multifield coupling is frequently encountered and also an active area of research in geotechnical *** this work,a particle-resolved direct numerical simulation(PR-DNS)technique is extended to simulate particle-fluid interaction problems involving heat transfer at the grain *** this extended technique,an immersed moving boundary(IMB)scheme is used to couple the discrete element method(DEM)and lattice Boltzmann method(LBM),while a recently proposed Dirichlet-type thermal boundary condition is also adapted to account for heat transfer between fluid phase and solid *** resulting DEM-IBM-LBM model is robust to simulate moving curved boundaries with constant temperature in thermal *** facilitate the understanding and implementation of this coupled model for non-isothermal problems,a complete list is given for the conversion of relevant physical variables to lattice ***,benchmark tests,including a single-particle sedimentation and a two-particle drafting-kissing-tumbling(DKT)simulation with heat transfer,are carried out to validate the accuracy of our coupled *** further investigate the role of heat transfer in particle-laden flows,two multiple-particle problems with heat transfer are *** examples demonstrate that the proposed coupling model is a promising high-resolution approach for simulating the heat-particle-fluid coupling at the grain level.

关键词： Particle-fluid interaction Heat transfer Discrete element method(DEM) Lattice Boltzmann method(LBM) Dirichlet-type thermal boundary Direct numerical simulation