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Megafossils of Betulaceae from the Oligocene of Qaidam Basin and their paleoenvironmental and phytogeographic implications

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Plant Diversity 2024年第1期46卷 101-115页

作者： Tao yan. Jia-Hao Cai yan.Zhi Dai Hong-yu Chen Lei Han Li Zhang Wei-yu liang Xu-Jun Li Wen-Jia Li Jing-yu Wu San-Ping Xie De-Fei yan School of Earth Sciences and Key Laboratory of Mineral Resources in Western China(Gansu Province) Lanzhou UniversityLanzhou 730000China Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China Center for Research and Education on Biological Evolution and Environments School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau,China relies on discovering new plant *** Qaidam Basin has long been regarded as an ideal‘field laboratory’to investigate the paleoclimate and paleobiological evolution of the northern Tibetan ***,fossil angiosperms from the Qaidam Basin are rare,and our knowledge of its paleovegetation is ***,we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin(Huatugou area).Comparative morphological analysis led us to assign the fruits to the Betula subgenus Betula and the leaves to Carpinus *** findings,together with other reported fossil plants from the same locality,reveal a close floristic linkage between the Qaidam Basin and Europe during the *** northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late *** floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies,which transported moisture and provided favorable climatic ***,fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest,which differs from the region’s modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene.

关键词： Paleoenvironment Biogeography Betulaceous fossil Qaidam basin Tibetan Plateau Oligocene

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Study of the pressure transient behavior of directional wells considering the effect of non-uniform flux distribution

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Petroleum Science 2024年第3期21卷 1765-1779页

作者： yan.Zhong liang Bai-Lu Teng Wan-Jing Luo School of Energy Resources China University of Geosciences(Beijing)Beijing100083China

During the production,the fluid in the vicinity of the directional well enters the wellbore with different rates,leading to non-uniform flux distribution along the directional ***,in all existing studies,it is oversimplified to a uniform flux distribution,which can result in inaccurate results for field ***,this paper proposes a semi-analytical model of a directional well based on the assumption of non-uniform flux ***,the direction well is discretized into a carefully chosen series of linear sources,such that the complex well trajectory can be captured and the nonuniform flux distribution along the wellbore can be considered to model the three-dimensional flow *** using the finite difference method,we can obtain the numerical solutions of the transient flow within the *** the aid of Green's function method,we can obtain the analytical solutions of the transient flow from the matrix to the *** complete flow behavior of a directional well is perfectly represented by coupling the above two types of transient ***,on the basis of the proposed model,we conduct a comprehensive analysis of the pressure transient behavior of a directional *** computation results show that the flux variation along the direction well has a significant effect on pressure *** addition,the directional well in an infinite reservoir may exhibit the following flow regimes:wellbore afterflow,transition flow,inclined radial flow,elliptical flow,horizontal linear flow,and horizontal radial *** horizontal linear flow can be observed only if the formation thickness is much smaller than the well ***,a dip region that appears on the pressure derivative curve indicates the three-dimensional flow behavior near the wellbore.

关键词： Directional well Pressure transient behavior Semi-analytical model Non-uniform flux

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Trudinger–Moser Inequalities on a Closed Riemann Surface with a Symmetric Conical Metric

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2263-2284页

作者： yu FANG yun yan.yan. College of Teacher Education Quzhou UniversityQuzhou 324003P.R.China Department of Mathematics Renmin University of ChinaBeijing 100872P.R.China

This is a continuation of our previous work(*** ***.,20,1295–1324,2020).Let(Σ,g)be a closed Riemann surface,where the metric g has conical singularities at finite *** G is a group whose elements are isometries acting on(Σ,g).Trudinger–Moser inequalities involving G are established via the method of blow-up analysis,and the corresponding extremals are also *** extends previous results of Chen(***.,1990),Iula–Manicini(Nonlinear Anal.,2017),and the authors(2020).

关键词： Trudinger-Moser inequality blow-up analysis conical singularity

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Carbon felt electrode coated with WS2 enables a high-performance polysulfide/ferricyan.de flow battery

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Rare Metals 2024年第10期43卷 5039-5047页

作者： liang-yu Li Su yan.Ying-Jia Huang Fang-Fang Zhong Jin-Chao Cao Mei Ding Chuan-Kun Jia College of Materials Science and Engineering Changsha University of Science and Technology Institute of Energy Storage Technology College of Energy and Power EngineeringChangsha University of Science and Technology Binzhou Institute of Technology Weiqiao-UCAS Science and Technology Park

Polysulfide/ferricyan.de flow batteries （S/Fe RFBs）,with the advantages of abundant earth reservation low cost,high safety,and environmental friendliness,have attracted significant interest and demonstrated noteworthy potential for practical ***,the battery performance,including the energy efficiency （EE）,voltage efficiency （VE）,and power density of the S/Fe RFBs remains low owing to the slow redox kinetics of polysulfide *** address these concerns,WS2was selected as the booster and deposited on a commercial carbon felt electrode （WS2–CF） to stimulate the redox reactions of polysulfide *** better hydrophilicity and smaller charge-transfer resistance,WS2–CF exhibits enhanced electrochemical activity toward polysulfide redox ***,the battery performance of S/Fe RFB with WS2–CF as the anode has been improved,with EE of 84%,VE of 84%,and a peak power density of 175.7 mW·cm-2,which are all higher than the cell only with the bare carbon felt （CF） as electrodes (76%,77% and 155.8 mW·cm-2,respectively).Furthermore,the cycling life of the S/Fe RFB with WS2–CF has been prolonged to 2200 cycles with a capacity retention of 96% a 40 mA·cm-2because of the good stability of WS2–CF as the ***,under the same conditions,the S/Fe RFB without WS2–CF terminated after 1500 cycles with a fast capacity *** successful utilization of WS2as a booster on an electrode provides an efficient strategy for obtaining advanced S/Fe RFBs for practical applications.

关键词： Carbon felt Energy storage Polysulfide/ferricyan.de flow battery Tungsten disulfide

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Adhesion property of AlCrNbSiTi high-entropy alloy coating on zirconium:experimental and theoretical studies

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Nuclear Science and Techniques 2024年第8期35卷 79-91页

作者： Bao‑liang Zhang Wen‑Guan Liu Meng‑He Tu Can Fang yan.Liu yu‑Hui Wang Yong Hu Hui Wang China Institute of Atomic Energy Beijing 102413China Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China

Experimental scratch tests and first-principles calculations were used to investigate the adhesion property of AlCrNbSiTi high-entropy alloy(HEA)coatings on zirconium *** HEA and Cr coatings were deposited on Zr alloy substrates using multi-arc ion plating technology,and scratch tests were subsequently conducted to estimate the adhesion property of the *** results indicated that Cr coatings had better adhesion strength than HEA coatings,and the HEA coatings showed *** special quasi-random structure approach was used to build HEA models,and Cr/Zr and HEA/Zr interface models were employed to investigate the cohesion between the coatings and Zr substrate using first-principles *** calculated interface energies showed that the cohesion between the Cr coating and the Zr substrate was stronger than that of the HEA coating with *** contrary to Al or Si in the HEA coating,Cr,Nb,and Ti atoms binded strongly with Zr *** on the calculated elastic constants,it was found that low Cr and high Al content decreased the mechanical performances of HEA ***,this study demonstrated the utilization of a combined approach involving first-principles calculations and experimental studies for future HEA coating development.

关键词： High-entropy alloy coating Cr coating Adhesion property Scratch test First-principles calculation

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Oxidation behavior of Ni-based superalloy GH4738 under tensile stress

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Rare Metals 2024年第8期43卷 3913-3920页

作者： Ji-Chong Hu Hai-liang Huang Chong-Chong Wu Xiao-yu Sun Jie Wang yan.Hong yan. Jing-Long Qu liang Jiang Jin-He Dou yan. Chen Institute for Advanced Studies in Precision Materials Yantai UniversityYantai 264005China Department of Management and Engineering Linkoping University58183LinkopingSweden Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Gaona Aero Material Co. LtdBeijing 100081China College of Artificial Intelligence and Big Data Shandong First Medical University and Shandong Academy of Medical SciencesJinan250117China

Revealing the oxidation behavior of superalloys is crucial for optimizing material properties and extending service *** study investigated the oxidation behavior of superalloy GH4738 under stress states at 850℃.High-throughput specimens were fabricated to withstand different stresses at the same *** oxidation s amples were analyzed using the mass gain method to obtain oxidation kinetic *** results show that the external stress below 200 MPa could improve the oxidation resistance of the *** tensile stress increasing,the oxide layer becomes thinner,denser and more complete,while internal oxidation *** tensile stress alters the structure of the external oxide layer from a two-layer to a threelayer *** Cr_(2)O_(3) oxide layer inhibits the outward diffusion of Ti,leading to Ti enrichment at the oxide-matrix interface and altering the oxidation mechanism of GH4738.

关键词： Ni-based Superalloy Oxidation behavior Tensile stress Oxide layer

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A deep learning model based on contrast-enhanced computed tomography for differential diagnosis of gallbladder carcinoma

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 376-384页

作者： Fei Xiang Qing-Tao Meng Jing-Jing Deng Jie Wang Xiao-yuan liang Xing-yu Liu Sheng yan Department of Hepatobiliary Pancreatic Surgery Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Department of Radiology Affiliated Chuzhou First People’s HospitalAnhui Medical UniversityChuzhou 239000China

Background:Gallbladder carcinoma(GBC)is highly malignant,and its early diagnosis remains *** study aimed to develop a deep learning model based on contrast-enhanced computed tomography(CT)images to assist radiologists in identifying ***:We retrospectively enrolled 278 patients with gallbladder lesions(>10 mm)who underwent contrast-enhanced CT and cholecystectomy and divided them into the training(n=194)and validation(n=84)*** deep learning model was developed based on ResNet50 *** and clinical models were built based on support vector machine(SVM)*** comprehensively compared the performance of deep learning,radiomics,clinical models,and three ***:Three radiomics features including LoG_3.0 gray-level size zone matrix zone variance,HHL firstorder kurtosis,and LHL gray-level co-occurrence matrix dependence variance were significantly different between benign gallbladder lesions and GBC,and were selected for developing radiomics *** regression analysis revealed that age≥65 years[odds ratios(OR)=4.4,95%confidence interval(CI):2.1-9.1,P37 U/mL(OR=4.0,95%CI:1.6-10.0,P=0.003)were significant clinical risk factors of *** deep learning model achieved the area under the receiver operating characteristic curve(AUC)values of 0.864(95%CI:0.814-0.915)and 0.857(95%CI:0.773-0.942)in the training and validation datasets,which were comparable with radiomics,clinical models and three *** sensitivity of deep learning model was the highest both in the training[90%(95%CI:82%-96%)]and validation[85%(95%CI:68%-95%)]***:The deep learning model may be a useful tool for radiologists to distinguish between GBC and benign gallbladder lesions.

关键词： Gallbladder carcinoma Computed tomography Deep learning Radiomics

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High-temperature dielectric polymer composite for high power energy storage applications

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Science China Chemistry 2024年第8期67卷 2425-2426页

作者： Xiangyan.yu Haixue yan School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUK

Polymer-based dielectric films are the main component of dielectric capacitors due to their high power density, which plays an important role in power electrical systems using renewable energy, such as electric vehicles, solar panel, wind power [1]. However, the energy density of dielectrics is lower than that of other energy storage materials, such as batteries or supercapacitors. High energy density of the dielectric is related to high dielectric permittivity and high dielectric breakdown strength (DBS).

关键词： composite dielectric energy

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Fine-grained grid computing model for Wi-Fi indoor localization in complex environments

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Journal of Electronic Science and Technology 2024年第1期22卷 42-52页

作者： yan.liang Song Chen Xin Dong Tu Liu School of Computer Engineering Chengdu Technological UniversityChengdu611730China HAN Networks Corporation Limited Beijing100094China

The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor ***,the construction of the fingerprint database is quite *** when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is *** appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)*** this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization *** points(RPs)are generated in the grid by the FGGC ***,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex *** a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous *** proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy *** mean error of the proposed model is 0.36 m,far lower than that of previous ***,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor *** also shows high-accuracy performance with a fast running speed even under a large-size *** results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue.

关键词： Fine-grained grid computing (FGGC) Indoor localization Path loss Random forest Reference points(RPs)

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Multiple Nanoparticles Coupling Strategy for Enhancing Optical Filter Performance of Spectral Splitter Used in Photovoltaic/Thermal System

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Journal of Thermal Science 2024年第1期33卷 368-382页

作者： liang Huaxu HUANG Xin WANG Fuqiang CHENG Ziming DONG yan School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of New Energy Harbin Institute of Technology at WeihaiWeihai 264209China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore

Selective absorptive nanofluid can pre-absorb certain sunlight wavelength that cannot be used by PV and transmits remaining sunlight to the surface of PV,which can decouple PV from the thermal receiver *** order to improve the harvesting of electricity and high-temperature thermal nanofluid,it is important to design an optimal optical filter window(transmit sunlight with wavelengths of 732-1067 nm to the surface of the photovoltaic cell and absorb the remaining sunlight).However,designing optimal optical filter is facing following challenges:(1) inherently narrow selective absorptivity property of single nanoparticle;(2) simplified numerical calculation method calculating transmittance;(3) ignoring the shape of the *** this study,the idea of using multiple nanoparticles coupling effect to design an optical filter is proposed,which can superimpose the narrow absorption bandwidth of different nanoparticles to obtain a wide absorption bandwidth of the whole *** addition,an improved transmission method considering light-matter interaction at air/vessel and liquid/vessel interfaces is adopted to compute the *** results calculated by improved transmission method are more accurate than widely used traditional Lambert-Beer law,which is verified by experimental ***,the effect of nanoparticle shape on spectral transmittance is also investigated,which shows that spiny Ag can approximately extend absorbance from 400 nm to 600 nm compared to nanosphere ***,the results show that optical filter efficiency of nanofluids with multiple nanoparticles coupling(Ag,spiny Ag,ZnO,ITO) can reached up to 35%.

关键词： solar energy PV/T nanofluid optimal optical filter radiative transfer spectral splitting

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