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Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake

Geodesy and Geodynamics 2024年第3期15卷 219-229页

作者： Geng Zhang Jianqiao Xu Xiaodong Chen Heping Sun Lizhuo gong State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430077China University of Chinese Academy of Sciences Beijing100049China

It is commonly believed that the atmosphere is decoupled from the solid ***,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric *** increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling ***,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 *** are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 *** paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United *** numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter *** results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h.

关键词： Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere

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Occurrence of dark septate endophytes in Phragmites australis in the Baiyang Lake and their resistance to Cd stress

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Pedosphere 2024年第2期34卷 484-496页

作者： Minghui XU Xia LI Qiannan YE Feng gong Xueli HE School of Life Sciences Hebei UniversityBaoding 071002China Key Laboratory of Microbial Diversity Research and Application of Hebei Province Hebei UniversityBaoding 071002China

Heavy metal pollution poses a serious hazard to human health,and microbial remediation of heavy metals in soil has been widely studied.A group of ascomycetes classified as dark septate endophytes(DSEs)colonize plant roots and benefit host plants under abiotic stress *** this study,Phragmites australis,a common remediation plant in the Baiyang Lake in North China,was *** and roots of *** were collected in typical heavy metal-contaminated sites,and the species diversity and community structure of DSEs in *** roots were *** addition,DSE strains were isolated,cultured,and tested for their tolerance to Cd *** results showed that DSEs occurred extensively in *** roots,forming typical dark septate hyphae,with a total colonization rate of 19.7%–83.1%.Morphological and internal transcribed spacer sequencing analyses were used to identify 10 species within 9 genera of DSE *** these fungi,6 strains with considerable resistance to Cd stress were *** biomasses of Poaceascoma helicoides,Alternaria doliconidium,and Acrocalymma vagum strains increased as the Cd levels *** results can not only help to understand plant-DSE interactions in wetland environments,but also provide a theoretical basis for making full use of DSE fungi to alleviate heavy metal contamination in soil.

关键词： ascomycete colonization rate contaminated site evenness index heavy metal Shannon-Wiener index Simpson index wetland

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PRX1-positive mesenchymal stem cells drive molar morphogenesis

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International Journal of Oral Science 2024年第2期16卷 293-305页

作者： Xiaoqiao Xu Xuyan gong Lei Zhang Han Zhang Yao Sun Department of Implantology Stomatological Hospital and Dental School of Tongji UniversityShanghai Engineering Research Center of Tooth Restoration and RegenerationShanghaiChina

Mammalian teeth,developing inseparable from epithelial-mesenchymal interaction,come in many shapes and the key factors governing tooth morphology deserve to be *** merging single-cell RNA sequencing analysis with lineage tracing models,we have unearthed a captivating correlation between the contrasting morphology of mouse molars and the specific presence of PRX1^(+)cells within *** PRX1^(+)cells assume a profound responsibility in shaping tooth morphology through a remarkable divergence in dental mesenchymal cell *** into the mechanisms,we have discovered that Wnt5a,bestowed by mesenchymal PRX1^(+)cells,stimulates mesenchymal cell proliferation while orchestrating molar morphogenesis through WNT signaling *** loss of Wnt5a exhibits a defect phenotype similar to that of *** addition of WNT5A can successfully reverse the inhibited cell proliferation and consequent deviant appearance exhibited in Prx1-deficient tooth *** findings bestow compelling evidence of PRX1-positive mesenchymal cells to be potential target in regulating tooth morphology.

关键词： Wnt5a mesenchymal inhibited

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Effect of Iron on the Stability of Rhodochrosite at the Topmost Lower Mantle Conditions

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Journal of Earth Science 2024年第2期35卷 504-513页

作者： Tianlei Zhai Fei Qin Shengxuan Huang Shan Qin Yu gong Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing100871China School of Earth Sciences and Resources China University of GeosciencesBeijing100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China

Carbonates are viewed as the principal oxidized carbon carriers during subduction,and thus the stability of subducted carbonates has significant implications for the deep carbon *** we investigate the high pressure-temperature behaviors of rhodochrosite in the presence of iron up to∼34 GPa by in-situ X-ray diffraction and ex-situ Raman *** relatively low temperature below∼1500 K,MnCO_(3)breaks down into MnO and CO_(2).Upon heating to∼1800 K,however,the MnCO_(3)-Fe^(0)reactions occur with the formation of Mn_(3)O_(4),Fe^(O)and reduced carbon.A'three-stage'reaction mechanism is proposed to understand the kinetics of the carbon-iron-manganese redox *** results suggest that Fe^(0)can serve as a reductant to greatly affect the stability of rhodochrosite,which implies that the effect of Fe-metal should be seriously considered for the high pressure-temperature behaviors of other predominant carbonates at Earth's mantle conditions,particularly at depths greater than∼250 km.

关键词： deep carbon cycle rhodochrosite reduced mantle diamond formation high pressure tectonics geochemistry

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Rural labor migration and farmers’arrangements of rice production systems in Central China:Insight from the intergenerational division of labor

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Journal of Integrative Agriculture 2024年第9期23卷 3200-3214页

作者： Xue Shen Quanyu Yang Rongjun Ao Shengsheng gong Key Laboratory for Geographical Process Analysis&Simulation of Hubei Province/College of Urban and Environmental Sciences Central China Normal UniversityWuhan 430079China

Rice production is crucial for food security in China,and its relationship with rural labor migration has been studied *** migration in rural China has taken new forms in recent *** has been a discernible trend wherein adult children have started migrating to cities while their elderly parents return to villages to re-engage in on-farm *** phenomenon has notably shaped the intergenerational division of labor(IDL)within ***,it remains to be seen how farmers adjust their rice production systems in response to the *** age of 60 years for employment injury insurance is the eligibility threshold for off-farm employment and is used to obtain a source of exogenous variation in the *** on a representative household survey of 1,752 rice farmers in the Hubei Province of Central China,our fuzzy regression discontinuity analysis reveals that farmers in IDL households are more likely to adopt ratoon rice(RR)than single cropping rice(SR)or double cropping rice(DR).The effect of the IDL varies under different levels of operational scales and specialized agricultural service *** analysis suggests that farmers’arrangements are associated with two potential mechanisms of downward intergenerational *** transfer for urban housing purchases increases RR in IDL households,and time transfer for intergenerational childcare significantly promotes SR in IDL *** study enhances the understanding of the relationship between rural labor migration and rice production in China,providing a reference for adjusting rice production systems to ensure food security.

关键词： labor migration intergenerational division of labor rice production systems fuzzy regression discontinuity Central China

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Preheating-assisted solid-state friction stir repair of Al-Mg-Si alloy plate at different rotational speeds

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 725-736页

作者： Hui Wang Yidi Li Ming Zhang Wei gong Ruilin Lai Yunping Li State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Research Institute of Light Alloy Central South UniversityChangsha 410083China

Additive friction stir deposition(AFSD)is a novel structural repair and manufacturing technology has become a research hotspot at home and abroad in the past five *** this work,the microstructural evolution and mechanical performance of the Al-Mg-Si alloy plate repaired by the preheating-assisted AFSD process were *** evaluate the tool rotation speed and substrate preheating for repair quality,the AFSD technique was used to additively repair 5 mm depth blind holes on 6061 aluminum alloy *** results showed that preheat-assisted AFSD repair significantly improved joint bonding and joint strength compared to the control non-preheat substrate ***,increasing rotation speed was also beneficial to improve the metallurgical bonding of the interface and avoid volume *** preheating conditions,the UTS and elongation were positively correlated with rotation *** the process parameters of preheated substrate and tool rotation speed of 1000 r/min,defect-free specimens could be obtained accompanied by tensile fracture occurring in the substrate rather than the repaired *** UTS and elongation reached the maximum values of 164.2MPa and 13.4%,which are equivalent to 99.4%and 140%of the heated substrate,respectively.

关键词： additive friction stir deposition structural repair tool rotation speed Al alloy

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Development of CONTHAC-3D and hydrogen distribution analysis of HPR1000

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Nuclear Science and Techniques 2024年第2期35卷 210-221页

作者： Hui Wang Jing-Jing Li Yuan Chang gong-Lin Li Ming Ding China Nuclear Power Engineering Co.LTD. Beijing 100084China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin 100049China

An in-house code,CONTHAC-3D,was developed to calculate and analyze thermal-hydraulic phenomena in containments during severe ***-3D is a three-dimensional computational fluid dynamics code that can be applied to predict gas flow,diffusion,and steam condensation in a containment during a severe hypothetical accident,as well as to obtain an estimate of the local hydrogen concentration in various zones of the ***-3D was developed using multiple models to simulate the features of the proprietary systems and equipment of HPR1000 and ACP100,such as the passive cooling system,passive autocatalytic recombiners and the passive air cooling *** validate CONTHAC-3D,a GX6 test was performed at the Battelle Model Containment *** hydrogen concentration and temperature monitored by the GX6 test are accurately predicted by ***,the hydrogen distribution in the HPR1000 containment during a severe accident was *** results show that the hydrogen removal rates calculated using CONTHAC-3D for different types of PARs agree well with the theoretical values,with an error of less than 1%.As the accident progresses,the hydrogen concentration in the lower compartment becomes higher than that in the large space,which implies that the lower compartment has a higher hydrogen risk than the dome and large space at a later stage of the *** amount of hydrogen removed by the PARs placed on the floor of the compartment is small;therefore,raising the installation height of these recombiners appropriately is ***,we do not recommend installing all autocatalytic recombiners at high *** study findings in regard to the hydrogen distribution in the HPR1000 containment indicate that CONTHAC-3D can be applied to the study of hydrogen risk containment.

关键词： Hydrogen risk mitigation Pressurized water reactor HPR1000 Thermal hydraulic CONTHAC-3D

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Probability Distribution Characteristics of Strong Nonlinear Waves Under Typhoon Conditions in the Northern South China Sea

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Journal of Ocean University of China 2024年第3期23卷 583-593页

作者： gong Yijie XIE Botao FU Dianfu WANG Zhifeng PANG Liang College of Engineering Ocean University of ChinaQingdao 266100China CNOOC Research Institute Ltd. Beijing 100028China

The generation and propagation mechanism of strong nonlinear waves in the South China Sea is an essential research area. In this study, the third-generation wave model WAVEWATCH Ⅲ is employed to simulate wave fields under extreme sea states. The model, integrating the ST6 source term, is validated against observed data, demonstrating its credibility. The spatial distribution of the occurrence probability of strong nonlinear waves during typhoons is shown, and the waves in the straits and the northeastern part of the South China Sea show strong nonlinear characteristics. The high-order spectral model HOS-ocean is employed to simulate the random wave surface series beneath five different platform areas. The waves during the typhoon exhibit strong nonlinear characteristics, and freak waves exist. The space-varying probability model is established to describe the short-term probability distribution of nonlinear wave series. The exceedance probability distributions of the wave surface beneath different platform areas are compared and analyzed. The results show that with an increase in the platform area, the probability of a strong nonlinear wave beneath the platform increases.

关键词： strong nonlinear wave typhoon wave series probability distribution model exceedance probability

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Policy Network-Based Dual-Agent Deep Reinforcement Learning for Multi-Resource Task Offloading in Multi-Access Edge Cloud Networks

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China Communications 2024年第4期21卷 53-73页

作者： Feng Chuan Zhang Xu Han Pengchao Ma Tianchun gong Xiaoxue School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Institute of Intelligent Communication and Network Security Chongqing University of Posts and TelecommunicationsChongqing 400065China Key Laboratory of Big Data Intelligent Computing Chongqing University of Posts and TelecommunicationsChongqing 400065China School of Information Engineering Guangdong University of TechnologyGuangzhou 510006China

The Multi-access Edge Cloud(MEC) networks extend cloud computing services and capabilities to the edge of the networks. By bringing computation and storage capabilities closer to end-users and connected devices, MEC networks can support a wide range of applications. MEC networks can also leverage various types of resources, including computation resources, network resources, radio resources,and location-based resources, to provide multidimensional resources for intelligent applications in 5/***, tasks generated by users often consist of multiple subtasks that require different types of resources. It is a challenging problem to offload multiresource task requests to the edge cloud aiming at maximizing benefits due to the heterogeneity of resources provided by devices. To address this issue,we mathematically model the task requests with multiple subtasks. Then, the problem of task offloading of multi-resource task requests is proved to be NP-hard. Furthermore, we propose a novel Dual-Agent Deep Reinforcement Learning algorithm with Node First and Link features(NF_L_DA_DRL) based on the policy network, to optimize the benefits generated by offloading multi-resource task requests in MEC networks. Finally, simulation results show that the proposed algorithm can effectively improve the benefit of task offloading with higher resource utilization compared with baseline algorithms.

关键词： benefit maximization deep reinforcement learning multi-access edge cloud task offloading

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Recent progress in Prussian blue electrode for electrochromic devices

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Frontiers in Energy 2024年第2期18卷 160-186页

作者： Yongting ZHANG Wanzhong LI Hui gong Qianqian ZHANG Liang YAN Hao WANG Key Laboratory for New Functional Materials of the Ministry of Education Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China School of Instrument Science and Engineering Southeast UniversityNanjing 210096China Beijing Aerospace Times Laser Inertial Technology Company Beijing 100094China

Great progress has been made in the electrochromic(EC)technology with potential applications in various *** one of the most promising EC materials,Prussian blue(PB)has attracted great attention due to its excellent EC performance,such as low cost,easy synthesis,rich color states,chemical stability,suitable redox potential,and fast color-switching *** review summarizes the recent progress in PB electrodes and devices,including several typical preparation techniques of PB electrodes,as well as the recent key strategies for enhancing EC performance of PB ***,PB-based electrochromic devices(ECDs)have been widely used in various fields,such as smart windows,electrochromic energy storage devices(EESDs),wearable electronics,smart displays,military camouflage,and other *** opportunities and obstacles are suggested for advancing the development of PB-based *** comprehensive review is expected to offer valuable insights for the design and fabrication of sophisticated PBbased ECDs,enabling their practical integration into realworld applications.

关键词： Prussian blue electrochromism energy storage smart windows

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