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Is the Cape Stone Forest in Shantou City formed by wave erosion? A comparison of the pedestal rocks on the coasts and the mountains of Queshi in eastern Guangdong, china

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Journal of Mountain Science 2024年第5期21卷 1447-1463页

作者： CHEN Min WANG Wei School of Geography South China Normal UniversityGuangzhou 510631China

Cape Stone Forest is a group of granite rock pillars(pedestal rocks) towering over Shilin Lake, on the southern shore of Shantou Bay in eastern Guangdong, china. The rock pillars were previously identified as sea stacks because they have marine notch-like concave sidewalls at their base, and more importantly, the lake is immediately adjacent to the bay, which is exposed to the open sea. However, rock pillars similar in shape and size can also be found at the top of Queshi Mountain, which is only about 300 meters northwest of the lake and about 85 meters above sea level. Therefore, the marine origin of Cape Stone Forest is seriously questioned. In this study, 3D imagery and drone technology were used to collect data in the investigations without direct manual measurements in the water or on the mountain. It shows that the concave sidewalls of the rock pillars in the lake and on the mountains occur at different heights and are exposed to different directions, while a natural sea stack on Mayu Island at the mouth of Shantou Bay has a horizontal notch parallel to the sea level, although the granite rock of the sea stack is the same as that of the lake and the mountains. The eastern side of the island, where the sea stack is located, is exposed to the open sea but blocks large waves for the rock pillars in the lake. Therefore, the origin of Cape Stone Forest cannot be explained by wave-based mechanisms. The only satisfactory explanation that takes into account all the field evidence is that the narrow rock pillars of the lake and mountain were formed by chemical weathering that penetrated closely the spaced joints of the granite rock, and the notch-like concave sidewalls were formed by more effective chemical weathering at the base of the pillars.

关键词： Pedestal rock Granite Closely spaced joints Wave erosion Chemical weathering

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normalIZED SOLUTIONS FOR THE GENERAL KIRCHHOFF TYPE EQUATIONS

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Acta Mathematica Scientia 2024年第5期44卷 1886-1902页

作者： Wenmin LIU Xuexiu ZHONG Jinfang ZHOU School of Mathematical Sciences South China Normal UniversityGuangzhou510631China south china Research Center for Applied Mathematics and Interdisciplinary Studies&School of Mathematical Sciences South China Normal UniversityGuangzhou510631China

In the present paper,we prove the existence,non-existence and multiplicity of positive normalized solutions(λ_(c),u_(c))∈ℝ×H^(1)(ℝ^(N))to the general Kirchhoff problem-M\left(\int_{\mathbb{R}^N}\vert\nabla u\vert^2{\rm d}x\right)\Delta u+\lambda u=g(u)~\hbox{in}~\mathbb{R}^N,u\in H^1(\mathbb{R}^N),N\geq 1,satisfying the normalization constraint\int_{\mathbb{R}^N}u^2{\rm d}x=c,where M∈C([0,∞))is a given function satisfying some suitable *** argument is not by the classical variational method,but by a global branch approach developed by Jeanjean et al.[J Math Pures Appl,2024,183:44–75]and a direct correspondence,so we can handle in a unified way the nonlinearities g(s),which are either mass subcritical,mass critical or mass supercritical.

关键词： normalized solution Kirchhoff type equations general nonlinearities asymptotic behavior

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Migration Networks Pattern of china’s Floating Population from the Perspective of Complex Network

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Chinese Geographical Science 2024年第2期34卷 327-341页

作者： LIU Wangbao CHEN Ranran College of Geography Science South China Normal UniversityGuangzhou 510631China

Since china’s reform and opening-up,the growing disparity between urban and rural areas and regions has led to massive *** china’s Rural Revitalization Strategy and the industrial transfer from the eastern coastal areas to the inland,the migration direction and pattern of the floating population have undergone certain *** the 2017 china Migrants Dynamic Survey(CMDS),excluding Hong Kong,Macao,and Taiwan regions of china,organized by china’s National Health Commission,the relationship matrix of the floating population is constructed according to the inflow place of the interviewees and their outflow place(the location of the registered residence)in the questionnaire *** then apply the complex network model to analyze the migration direction and network pattern of china’s floating population from the city *** migration network shows an obvious hierarchical *** first-,second-,third-and fourth-tier distribution cities are municipalities directly under the central government,provincial capital cities,major cities in the central and western regions and ordinary cities in all provinces,*** migration trend is from the central and western regions to the eastern coastal *** migration network has‘small world’characteristics,forming nine *** shows that most node cities in the same community are closely linked and geographically close,indicating that the migration network of floating population is still affected by geographical *** the urban-rural and regional differences will promote the rational distribution this *** is necessary to strengthen the reform of the registered residence system,so that the floating population can enjoy urban public services comparable to other populations,and allow migrants to live and work in peace.

关键词： complex network floating population migration network spatial pattern community structure

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ON MONOTONE TRAVELING WAVES FOR NICHOLSON'S BLOWFLIES EQUATION WITH DEGENERATE p-LAPLACIAN DIFFUSION

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Acta Mathematica Scientia 2024年第4期44卷 1550-1571页

作者： Rui HUANG Yong WANG Zhuo YIN School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

We study the existence and stability of monotone traveling wave solutions of Nicholson's blowflies equation with degenerate p-Laplacian *** prove the existence and nonexistence of non-decreasing smooth traveling wave solutions by phase plane analysis ***,we show the existence and regularity of an original solution via a compactness ***,we prove the stability and exponential convergence rate of traveling waves by an approximated weighted energy method.

关键词： degenerate diffusion p-Laplacian traveling waves stability

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REFINEMENTS OF THE NORM OF TWO ORTHOGONAL PROJECTIONS

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Acta Mathematica Scientia 2024年第4期44卷 1229-1243页

作者： Xiaohui LI Meiqi LIU Chunyuan DENG School of Mathematics Science South China Normal UniversityGuangzhou 510631China

In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are *** use certain norm inequalities for positive contraction operator to establish norm inequalities for combination of orthogonal projections on a Hilbert ***,we give necessary and sufficient conditions under which the norm of the above combination of o`rthogonal projections attains its optimal value.

关键词： norm orthogonal projection positive operator spectral block operator valued matrix

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ESTIMATE ON THE BLOCH CONSTANT FOR CERTAIN HARMONIC MAPPINGS UNDER A DIFFERENTIAL OPERATOR

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Acta Mathematica Scientia 2024年第1期44卷 295-310页

作者：陈洁玲刘名生 School of Mathematical Sciences South China Normal UniversityGuangzhou510631China

In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded ***,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open ***,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors.

关键词： Bloch-Landau type theorem Bloch constant linear complex operator harmonic mapping biharmonic mapping univalent

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GLOBAL SOLUTIONS TO 1D COMPRESSIBLE NAVIER-STOKES/ALLEN-CAHN SYSTEM WITH DENSITY-DEPENDENT VISCOSITY AND FREE-BOUNDARY

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Acta Mathematica Scientia 2024年第1期44卷 195-214页

作者：丁时进李颖花王喻 School of Mathematical Sciences South China Normal UniversityGuangzhou510631China

This paper is concerned with the Navier-Stokes/Allen-Cahn system,which is used to model the dynamics of immiscible two-phase *** consider a 1D free boundary problem and assume that the viscosity coefficient depends on the density in the form ofη(ρ)=ρ^(α).The existence of unique global H^(2m)-solutions(m∈N)to the free boundary problem is proven for when 0<α<1/***,we obtain the global C^(∞)-solutions if the initial data is smooth.

关键词： Navier-Stokes/Allen-Cahn system density-dependent viscosity free boundary global solutions

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A Galaxy Image Augmentation Method Based on Few-shot Learning and Generative Adversarial Networks

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Research in Astronomy and Astrophysics 2024年第3期24卷 180-193页

作者： Yiqi Yao Jinqu Zhang Ping Du Shuyu Dong School of Artificial Intelligence South China Normal UniversityFoshan 528225China School of Computer Science South China Normal UniversityGuangzhou 510631China Guangdong Construction Vocational Technology Institute Guangzhou 511500China

Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data,but the key challenge is how to provide enough training data for the machine learning *** this article proposes an image data augmentation method that combines few-shot learning and generative adversarial *** Galaxy10 DECaLs data set is selected for the experiments with consistency,variance,and augmentation effects being *** popular networks,including AlexNet,VGG,and ResNet,are used as examples to study the effectiveness of different augmentation methods on galaxy morphology *** results show that the proposed method can generate galaxy images and can be used for expanding the classification model’s training *** to comparative studies,the best enhancement effect on model performance is obtained by generating a data set that is 0.5–1 time larger than the original data ***,different augmentation strategies have considerably varied effects on different types of ***-GAN achieved the best classification performance on the ResNet network for In-between Round Smooth Galaxies and Unbarred Loose Spiral Galaxies,with F1 Scores of 89.54%and 63.18%,*** comparison reveals that various data augmentation techniques have varied effects on different categories of galaxy morphology and machine learning ***,the best augmentation strategies for each galaxy category are suggested.

关键词： techniques image processing-galaxies structure-galaxies general

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Unraveling the mechanism of potassium metal capacitor for highly efficient charge storage

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Science china Chemistry 2024年第5期67卷 1578-1588页

作者： Qianqian Yao Pei Tang Kunyao Peng Zhenyuan Miao Yuecong Chen Qingyun Dou Xingbin Yan Department of Materials Science and Engineering Sun Yat-sen UniversityGuangzhou 510275China south china Academy of Advanced Optoelectronics South China Normal UniversityGuangzhou 510006China

Although hybrid metal ion capacitors(MICs) are highly desired to achieve both high power density of supercapacitors and high energy density of rechargeable batteries, the mismatch problem of electrochemical kinetics of negative and positive electrodes in MICs hampers the realization of this goal. Here, a new hybrid capacitor concept-potassium metal capacitor(PMC) is proposed for the first time, where potassium metal and commercial activated carbon(AC) without any modification are applied as negative and positive electrodes, respectively, and the electrolyte is the same as that of non-aqueous potassium ion batteries. The simplest PMC prototype exhibits a good combination of high energy density(184.9 Wh kg^(-1)) and power density(12.4 kW kg^(-1)), which benefits from the synergistic effect of potassium metal and AC electrode. The former experiences fast potassium plating/striping during charging and discharging, and the later possesses complex multiple charge behaviors driven by low potential of potassium metal. Specifically, below open-circuit voltage, transportation of solvated cations in AC pores plays an important role;beyond this voltage, synergy actions of cations and anions, including adsorption/desorption of solvated cations and anions, and ions exchange between them, dominate the capacitance contribution. This work enriches the types of MICs, and deepens the understanding of the energy storage mechanism of non-aqueous hybrid metal capacitors.

关键词： hybrid capacitor potassium metal activated carbon charge storage mechanism

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Upcycling the spent graphite/LiCoO_(2) batteries for high-voltage graphite/LiCoPO_(4)-co-workable dual-ion batteries

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1745-1751页

作者： Miao Du Hongyan Lü Kaidi Du Shuohang Zheng Xiaotong Wang Xiaotong Deng Ronghua Zeng Xinglong Wu Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education Northeast Normal UniversityChangchun 130024China Faculty of Chemistry Northeast Normal UniversityChangchun 130024China School of Chemistry South China Normal UniversityGuangzhou 510006China

The worldwide proliferation of portable electronics has resulted in a dramatic increase in the number of spent lithium-ion batteries(LIBs).However,traditional recycling methods still have limitations because of such huge amounts of spent ***,we proposed an ecofriendly and sustainable double recycling strategy to concurrently reuse the cathode(LiCoO_(2))and anode(graphite)materials of spent LIBs and recycled LiCoPO_(4)/graphite(RLCPG)in Li^(+)/PF^(-)_(6) co-de/intercalation dual-ion *** recycle-derived dualion batteries of Li/RLCPG show impressive electrochemical performance,with an appropriate discharge capacity of 86.2 mAh·g^(-1) at25 mA·g^(-1) and 69%capacity retention after 400 *** recycling of the cathode and anode from spent LIBs avoids wastage of resources and yields cathode materials with excellent performance,thereby offering an ecofriendly and sustainable way to design novel secondary batteries.

关键词： recycle lithium cobalt oxide lithium cobalt phosphate graphite dual-ion batteries spent lithium-ion batteries

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