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A novel relationship between elastic modulus and void ratio associated with principal stress for coral calcareous sand

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1033-1048页

作者： Ran gao Jianhong Ye State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Elastic moduli,*** modulus G and bulk modulus K,are important parameters of geotechnical materials,which are not only the indices for the evaluation of the deformation ability of soils but also the important basic parameters for the development of the constitutive models of geotechnical *** this study,a series of triaxial loading-unloading-reloading shear tests and isotropic loading-unloadingreloading tests are conducted to study several typical mechanical properties of coral calcareous sand(CCS),and the void ratio evolution during loading,unloading and *** test results show that the stress-strain curves during multiple unloading processes are almost parallel,and their slopes are much greater than the deformation modulus at the initial stage of *** relationship between the confining pressure and the volumetric strain can be defined approximately by a hyperbolic equation under the condition of monotonic loading of confining *** the condition of confining pressure unloading,the evolution of void ratio is linear in the e-lnp0 plane,and these lines are a series of almost parallel lines if there are multiple processes of *** on the experimental results,it is found that the modified Hardin formulae for the elastic modulus estimation have a significant deviation from the tested values for *** on the experimental results,it is proposed that the elastic modulus of soils should be determined by the intersection line of two spatial surfaces in the G/K-e-p’/pa space(pa:atmosphere pressure).“Ye formulation”is further proposed for the estimation of the elastic modulus of *** new estimation formulation for soil elastic modulus would provide a new method to accurately describe the mechanical behavior of granular soils.

关键词： Coral calcareous sand(CCS) Elastic shear modulus Elastic bulk modulus Triaxial test Estimation formulation Ye formulation

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The late Early-Paleozoic granitic magmatism in Northwestern Fujian, China: constraints on intraplate orogeny in the South China block

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Acta Geochimica 2024年第1期43卷 134-149页

作者： WanLi gao ZongXiu Wang Institute of Geomechanics Chinese Academy of Geological ScienceBeijing 100081People’s Republic of China Key Laboratory of Paleomagnetism and Tectonic Reconstruction of Ministry of Natural Resources Beijing 100081People’s Republic of China

The Early Paleozoic tectono-thermal event was a significant orogenic activity during the Phanerozoic era,which had a profound impact on the early crust of the South China Block(SCB) and established the foundation for later tectonic *** Wuyi-Yunkai orogenic belt in Southeastern China was extensively exposed to Early Paleozoic magmatism,the genetic mechanism of which remains *** shed light on this issue,detailed petrological,geochemical,and zircon U-Pb-Hf isotopic studies were carried out on two granitoids,namely the Yuntongshan pluton and the gaoqiao pluton,identified in the central *** U-Pb chronology of the Yuntongshan and gaoqiao bodies yielded ages of437±4 Ma(MSWD=2.2) and 404±2 Ma(MSWD=12),respectively,indicating that they were emplaced during the Early Silurian and Early Devonian *** granitoids are primarily composed of biotite-granite and biotite-monzonitic-granites,with high concentrations of S_(i)O_(2)(73.59-75.91 wt%),K_(2)O+Na_(2)O(8.31-8.73wt%),and low contents of MgO,CaO,Cr,*** are classified as high-K calc-alkaline and weakly metaluminous-strongly peraluminous S-type *** granitoids are enriched in light rare earth elements(LREEs) and large ion lithophile elements(LILEs) and depleted in heavy rare earth elements(HREEs) and high field strength elements(HFSEs) with arc *** εHf(t) values of-3.3 to-15.4 with two-stage Hf model ages ranging from 2829 to 1644 Ma,combined with the presence of Neoproterozoic inherited zircons,suggest that the primary magma of these granitoids was derived from the partial melting of Neoproterozoic crust with a Paleoproterozoic crustal model *** findings,combined with the spatio-temporal distribution of regional magmatism,reveal that the late Early-Paleozoic granitoids formed in the intraplate orogenic background originating from the subduction of the proto-Tethys Ocean and proto-Pacific Ocean around the margin of the east Gondwana supercontinent.

关键词： Late Early-Paleozoic Granites Intraplate orogeny Cathysian block Zircon U-Pb-Hf Isotopic composition

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Efficacy of robot-assisted thoracoscopic surgery in the treatment of pulmonary sequestration in children

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World Journal of Pediatric Surgery 2024年第2期7卷 119-124页

作者： Liang Liang Zheng Tan ting Huang Yue gao Jian Zhang Jiangen Yu Jie Xia Qiang Shu Departmentof Thoracic Surgery Children's HospitalZhejiang University School of MedicineNational Clinical ResearchCenterforChild HealthHangzhouZhejiangChina Department of Cardiac surgery Children'sHospital.Zheiiang surgery Children's HospitalZhejiang University School of MedicineNationalClinical Research Center for Child HealthHangzhouZhejiangChina

Objective This study was performed to evaluate the efficacy of robot-assisted thoracoscopic surgery(RATS)in the treatment of pulmonary sequestration(PS)in *** All video-assisted thoracoscopic surgery(VATS)and RAST performed on patients with PS at a single center from May 2019 to July 2023 were *** x2 and Wilcoxon tests were used to compare the perioperative outcomes between VATS and RATS *** Ninety-three patients underwent RATS while 77 patients underwent *** both two groups,one patient converted to thoracotomy and no surgical mortality *** median operation time was longer for the RATS group compared with the VATS group(75 min vs.60 min,p<0.001).A lower ratio of chest tube indwelling(61.3%vs.90.9%,p<0.001),fewer drainage days(1.0 day vs.2.0 days,p<0.001),and a shorter postoperative length of stay(5.0 days vs.6.0 days,p<0.001)were found in the RATS group than that in the VATS *** significant difference was found in the incidence of short-term postoperative complications(hydrothorax and pneumothorax)between two *** RATS was safe and effective in children with PS over 6 months old and more than 7 ***,RATS led to better short-time postoperative outcome than ***-institutional studies are warranted to compare differences in long-term outcomes between RATS and VATS.

关键词： surgery sequestration robot

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数字经济赋能海洋经济高质量发展

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经济问题 2024年第6期 42-50页

作者：马文婷邢文利高若大连海事大学马克思主义学院辽宁大连116026

海洋经济高质量发展是加快中国海洋强国建设的基础和关键。海洋经济高质量发展要求实现从“量的积累”迈向“质的飞跃”,更好地满足人民日益增长的美好生活需要。近年来中国海洋经济增速放缓,海洋经济领域固有矛盾严重阻滞了其高质量发... 详细信息

海洋经济高质量发展是加快中国海洋强国建设的基础和关键。海洋经济高质量发展要求实现从“量的积累”迈向“质的飞跃”,更好地满足人民日益增长的美好生活需要。近年来中国海洋经济增速放缓,海洋经济领域固有矛盾严重阻滞了其高质量发展,急需运用新的方式加以整改。而自人类进入数字时代以来,数字经济已成为助推经济内容变革、速率变革和动力变革的“提速器”,中国作为世界第二大数字经济体,需要发挥数字经济功用从而打破传统时空概念对海洋经济活动的限制与束缚,缓解资源错配、时间错配、空间错配等问题,赋予海洋经济更多可能性的同时推动其高质量发展。对数字经济与海洋经济高质量发展的双向联动作用进行分析,从马克思社会再生产理论对赋能机理加以阐释,同时深入分析二者融合现状,并提出相应的政策建议,对推进海洋强国和中国式现代化建设具有重要的理论意义和实践指引价值。

关键词：数字经济海洋经济高质量发展社会再生产理论

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Molecule doping enables high-quality perovskite junctions for all-perovskite tandem solar cells

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National Science Review 2024年第7期11卷 69-70页

作者： Lingeswaran Arunagiri Feng gao Department of Physics Chemistry and Biology(IFM) Link?ping University

The maximum theoretical power conversion efficiency(PCE) for single-junction solar cells based on the Shockley-Queisser(S-Q) model is 33.7% for an optimal bandgap(Eg) of 1.34 eV under 1-sun illumination [1]. Multijunction(tandem) solar cells present a realistic option for overcoming the S-Q limit and achieving efficiency of >40%due to decreased thermalization loss in tandem configuration [2].

关键词： METAL HALIDE PEROVSKITES

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A novel cascaded H-bridge photovoltaic inverter with flexible arc suppression function

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Global Energy Interconnection 2024年第4期7卷 513-527页

作者： Junyi Tang Wei gao College of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108P.R.China

This paper presents a novel approach that simultaneously enables photovoltaic(PV)inversion and flexible arc suppression during single-phase grounding *** compensate for ground currents through an arc-elimination function,while outputting a PV direct current(DC)power *** method effectively reduces the residual grounding *** reduce the dependence of the arc-suppression performance on accurate compensation current-injection models,an adaptive fuzzy neural network imitating a sliding mode controller was *** online adaptive adjustment law for network parameters was developed,based on the Lyapunov stability theorem,to improve the robustness of the inverter to fault and connection ***,a new arc-suppression control exit strategy is proposed to allow a zerosequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation *** results showed that the proposed method can effectively achieve fast arc suppression and reduce the fault impact current in single-phase grounding *** to other methods,the proposed method can generate a lower residual grounding current and maintain good arc-suppression performance under different transition resistances and fault locations.

关键词： Photovoltaic inverter Flexible arc suppression Adaptive control Fuzzy neural network Sliding mode control Exit strategy

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Ancient DNA unravels species identification from Laosicheng site,Hunan Province,China,and provides insights into maternal genetic history of East Asian leopards

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Zoological Research 2024年第1期45卷 226-229页

作者： Ming Zhang Cai-Hui Wang Yu-Xin Zheng Qi-gao Jiangzuo Ye-Mao Hou Peng Cao Qing-Yan Dai ruo-Wei Yang Feng Liu Xiao-Tian Feng Lin-Heng Mo Qiao-Mei Fu China-Central Asia"the Belt and Road"Joint Laboratory on Human and Environment Research Key Laboratory of Cultural Heritage Research and ConservationSchool of Culture HeritageNorthwest UniversityXi’anShaanxi 710127China Shanghai Qi Zhi Institute Shanghai 200232China College of Life Sciences Northwest UniversityXi’anShaanxi 710127China Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyCenter for Excellence in Life and PaleoenvironmentChinese Academy of SciencesBeijing 100044China Cultural Relics and Archaeology Institute of Hunan ChangshaHunan 410083China University of the Chinese Academy of Sciences Beijing 100049China

DEAR EDITOR,The Laosicheng site in Yongshun County,Hunan Province,China,plays an important role in elucidating the animal population composition of the region prior to the middle Qing Dynasty(approximately 300 years ago).This site has yielded a substantial number of animal bones,11960 of which have been identified to the species level,serving as direct evidence of ancient animal populations(Hunan Provincial Institute of Cultural Relics and Archaeology,2018).

关键词： Hunan Ancient insight

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Contrasting physical mechanisms of yellowfin tuna fluctuations between the western and eastern Indian Ocean

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Journal of Oceanology and Limnology 2024年第3期42卷 960-971页

作者： Peng LIAN Le gao Key Laboratory of Ocean Observation and Forecasting and Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory for Ocean Dynamics and Climate Laoshan LaboratoryQingdao 266061China

As an economically critical pelagic migratory species,yellowfin tuna(Thunnus albacores,YFT)is very sensible to physical and environmental conditions,such as sea surface temperature(SST),ocean heat content(OHC),and the mixed layer depth(MLD).We investigated the impact of SST,OHC,and MLD on fluctuations of YFT catch in the western/eastern Indian Ocean using the long time series of 63-year environmental and YFT *** found that the impact of SST on YFT was heavily overestimated in the past,and MLD plays a more critical role in the YFT catch *** the MLD deepens(>34.8 m),SST was more influential in predicting the catches of YFT than OHC in the western Indian Ocean,and OHC was more critical to YFT than SST in the eastern Indian ***,when the MLD shallows(<34.8 m),MLD was more vital to predict the catch per unit effort(CPUE)of YFT than SST/OHC in the *** 2000,there was an asynchronous pattern of YFT CPUE induced by higher frequency variations and ocean hiatus of SST/OHC signals in the western and eastern Indian Oceans *** impact of the subsurface hiatus may induce the decrease of YFT in the eastern Indian *** above findings clarified a non-stationary relationship between the environmental factors and catches of YFT and provided new insights into variations in YFT abundance.

关键词： yellowfin tuna Indian Ocean sea surface temperature(SST) ocean heat content(OHC) mixed layer depth(MLD) hiatus

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Analytical modeling of piezoelectric meta-beams with unidirectional circuit for broadband vibration attenuation

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1665-1684页

作者： Jiawei MAO Hao gao Junzhe ZHU Penglin gao Yegao QU State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Broadband vibration attenuation is a challenging task in engineering since it is difficult to achieve low-frequency and broadband vibration control *** solve this problem,this paper designs a piezoelectric meta-beam with unidirectional electric circuits,exhibiting promising broadband attenuation *** analytical model in a closed form for achieving the solution of unidirectional vibration transmission of the designed meta-beam is developed based on the state-space transfer function *** method can analyze the forward and backward vibration transmission of the piezoelectric meta-beam in a unified manner,providing reliable dynamics solutions of the *** analytical results indicate that the meta-beam effectively reduces the unidirectional vibration across a broad low-frequency range,which is also verified by the solutions obtained from finite element *** designed meta-beam and the proposed analytical method facilitate a comprehensive investigation into the distinctive unidirectional transmission behavior and superb broadband vibration attenuation performance.

关键词： broadband vibration attenuation efficient closed-form analytical solution electromechanical coupling piezoelectric material vibration control

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Spatial distribution of supra-permafrost groundwater in the Qinghai-Tibet Engineering Corridor using inversion models

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Advances in Climate Change Research 2024年第1期15卷 31-41页

作者： Yu gao Ming-Tang CHAI Wei MA Yu-Tao gao State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Civil and Hydraulic Engineering Ningxia UniversityYinchuan 750021China

Supra-permafrost groundwater(SPG)is a key factor that causes damage to highways and railways in the Qinghai-Tibet Engineering Corridor(QTEC).It is difficult to monitor SPG in the field due to their complex formation mechanisms and movement *** single-site field monitoring studies limit the spatial and temporal precision of SPG spatial *** determine the moisture content of shallow soils and the SPG distribution along the QTEC,this work employed the temperature vegetation dryness index and remote sensing models for groundwater table distribution *** accuracies of the models were validated using mea-surements obtained from different sites in the *** the permafrost zones of the QTEC,72%,22%and 6%of the SPG were located at depths of 0.5-1,1 m,***,79.4%of the area along the Qinghai-Tibet Highway(QTH)(Xidatan-Tanggula)section contained *** these sections with SPG,37.9%have an SPG table at depths of 0.5-0.8 *** study preliminarily explored the SPG distribution in the QTEC with a 30 m *** findings can help improve the spatial scale of SPG research,provide a basis for the analysis of the hydrothermal mechanisms,and serve as a guide in the assessment of operational risks and road structure designs.

关键词： Dryness index Landsat Soil moisture Groundwater level Qinghai-Tibet Engineering Corridor

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