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Machine Learning and Data Fusion Approach for Elastic Rock Properties Estimation and Fracturability Evaluation

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Energy and AI 2024年第2期16卷 1-13页

作者： Yiwen gong Ilham El-Monier Mohamed Mehana The Ohio State University SimTech LLC Los Alamos National Laboratory

Accurate rock elastic property determination is vital for effective hydraulic fracturing,particularly Young’s modulus due to its link to rock *** study integrates interdisciplinary data for better predictions of elastic modulus,combining data mining,experiments,and calibrated *** used the microstructural insights extracted from rock images for geomechanical facies ***,the petrophysical data and well logs were correlated with shear wave velocity(Vs)and Young’s *** developed a machine-learning workflow to predict Young’s modulus and assess rock fracturability,considering mineral composition,geomechanics,and *** findings indicate that artificial neural networks effectively predict Young’s modulus,while K-Means clustering and hierarchical support vector machines excel in identifying rock and geomechanical *** Microscale thin section analysis in conjunction with fracture modeling enhances our understanding of fracture geometries and facilitates fracturability ***,fracturability is controlled by specific geomechanical facies during initiation and propagation and influenced by continuity of geomechanical facies in small depth *** conclusion,this study demonstrates data mining and machine learning potential for predicting rock properties and assessing fracturability,aiding hydraulic fracturing design optimization through diverse data and advanced methods.

关键词： Young’s modulus prediction fracability evaluation landing point selection rock mechanics machine learning

Multipass Streaming Algorithms for Regularized Submodular Maximization

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Tsinghua Science and Technology 2024年第1期29卷 76-85页

作者： Qinqin gong Suixiang Gao Fengmin Wang Ruiqi Yang Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124.China School of Mathematical Sciences University of Chinese Academy SciencesBeijing 100049China Beijing Jinghang Research Institute of Computing and Communication Beijing 100074China

In this work,we study a k-Cardinality Constrained Regularized Submodular Maximization(k-CCRSM)problem,in which the objective utility is expressed as the difference between a non-negative submodular and a modular *** multiplicative approximation algorithm exists for the regularized model,and most works have focused on designing weak approximation algorithms for this *** this study,we consider the k-CCRSM problem in a streaming fashion,wherein the elements are assumed to be visited individually and cannot be entirely stored in *** propose two multipass streaming algorithms with theoretical guarantees for the above problem,wherein submodular terms are monotonic and nonmonotonic.

关键词： submodular optimization regularized model streaming algorithms threshold

Large low-field reversible magnetocaloric effect in K_(3)Gd(PO_(4))_(2) at sub-Kelvin temperature

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Journal of Rare Earths 2024年第6期42卷 1087-1092,I0003页

作者： Haojie Wang Zhaojun Mo Jianjian gong Heng Tu Guochun Zhang Jun Shen School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Center for Crystal Research and Development Key Laboratory of Functional Crystals and Laser TechnologyKey Laboratory of CryogenicsTechnical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China Department of Energy and PowerEngineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing100081China

We synthesized a potassium gadolinium phosphate K3Gd(PO_(4))_(2)with monoclinic structure(P2_(1/m))by the high-temperature solid-state reaction *** lattice constants obtained by Rietveld refinements of XRD curve are a=0.7411 nm,b=0.5624 nm,and c=0.9433 *** and magnetocaloric properties of K_(3)Gd(PO_(4))_(2)were investigated in *** magnetic phase transition temperature of K3Gd(PO_(4))2 was determined by ultra-low temperature testing to be 0.58 K.K_(3)Gd(PO_(4))2 exhibits large magnetic entropy changes(-ΔSM).The maximum-ΔSM are 20.2 and 29.4 J/(kg·K)in the magnetic field variation(ΔH)of 1 and 2 T,respectively,which are larger than that of the commercial Gd_(3)Ga_(5)O_(12)(GGG).The maximum adiabatic temperature change(ΔT_(ad))reaches 5.91 K under a magnetic field change(ΔH)of 1 T.K_(3)Gd(PO_(4))_(2)is a potential magnetic refrigeration material for obtaining sub-Kelvin temperatures.

关键词： Ultra-low temperature Magnetocaloric effect Magnetic entropy change Magnetic refrigeration Rare earths

Spatiotemporal variations of ecosystem services and driving factors in the Tianchi Bogda Peak Natural Reserve of Xinjiang,China

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Journal of Arid Land 2024年第6期16卷 816-833页

作者： ZHU Haiqiang WANG Jinlong TANG Junhu DING Zhaolong gong Lu Key Laboratory of Sustainable Development of Xingjiang's Historical and Cultural Tourism Xinjiang UniversityUrumqi 830046China College of Tourism Xinjiang UniversityUrumqi 830046China Ecological Postdoctoral Research Station Xinjiang UniversityUrumqi 830046China College of Ecology and Environment Xinjiang UniversityUrumqi 830017China

Nature reserves play a significant role in providing ecosystem services and are key sites for biodiversity *** Tianchi Bogda Peak Natural Reserve(TBPNR),located in Xinjiang Uygur Autonomous Region,China,is an important ecological barrier area in the temperate arid *** evaluation of its important ecosystem services is of great significance to improve the management level and ecological protection efficiency of the *** the present study,we assessed the spatiotemporal variations of four ecosystem services(including net primary productivity(NPP),water yield,soil conservation,and habitat quality)in the TBPNR from 2000 to 2020 based on the environmental and social data using the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)*** addition,the coldspot and hotspot areas of ecosystem services were identified by hotspot analysis,and the trade-off and synergistic relationships between ecosystem services were analyzed using factor analysis in a geographic *** the study period,NPP and soil conservation values in the reserve increased by 48.20%and 25.56%,respectively;conversely,water yield decreased by 16.56%,and there was no significant change in habitat ***,both NPP and habitat quality values were higher in the northern part and lower in the southern part,whereas water yield showed an opposite *** analysis revealed that NPP showed a synergistic relationship with habitat quality and soil conservation,and exhibited a trade-off relationship with water *** yield and habitat quality also had a trade-off *** and habitat quality were affected by annual average temperature and Normalized Difference Vegetation Index(NDVI),respectively,while water yield and soil conservation were more affected by digital elevation model(DEM).Therefore,attention should be paid to the spatial distribution and dynamics of trade-off and synergistic relationships between ecosystem services in future ec

关键词： net primary productivity(NPP) water yield soil conservation habitat quality Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model geographic detector Tianchi Bogda Peak Natural Reserve

Genetic Analysis and Taste Quality of Main Conventional Japonica Rice Varieties Grown in Jiangsu Province

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Genetic Analysis and Taste Quality of Main Conventional Japo...

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

江苏省遗传学会2016年学术年会

作者： hongbing gong Shengyuan Zeng Chuang Li Shimin Zuo Dedao Jing Tianzi Lin Zongxiang Chen Yafang Zhang Huafei Qian Bo Yu Shenglan Sheng Xuebiao Pan Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Key Laboratory of Plant Functional Genomics of Ministry ofEducationYangzhou University Zhenjiang Agricultural Research Institute

Fifty indica-japonica specific SSR markers were employed to genotype 86 conventional japonica rice cultivars mainly planted in Jiangsu province and 41 loci showed polymorphism among *** amplifying in 86 rice varieties,a total of 113 alleles were detected at the 41 SSR loci,and the allele number ranged from two to six,with an average of 2.76 in each *** information content（PIC） value of these 41 SSR markers ranged from 0.02 to 0.84,with an average value of 0.48;Nei’s expected heterozygosity value of the 41 markers ranged from 0.02 to 0.68,and the average value was *** on the coefficient index ranged from 0.72 to 1.00,we divided the 86 cultivars into three groups by *** analysis of taste quality traits investigated under different environments indicated that the taste quality of conventional japonica rice cultivars in Jiangsu was correlated with the genetic *** long-day（LD） condition,the amylose content（AC） and protein content（PC） manifested a tendency of group I ＞ group II ＞ group III,while the taste value（TV） was *** under short-day（SD） condition,taste quality traits of group II and group III varied significantly compared with that under LD condition,while the traits of group I had no significant *** results indicated that the main cultivars grown in Jiangsu have a general taste quality and narrow genetic background,broadening the genetic basis is an important approach to breed japonica rice cultivars with environment insensitivity and good eating quality.

关键词： SSR marker Japonica rice Taste quality Genetic basis

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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

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

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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

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

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