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Dirac-geodesics with curvature term

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Science China Mathematics 2025年第2期68卷 433-446页

作者： qun Chen Mingwei zhang School of Mathematics and Statistics Wuhan UniversityWuhan 430072China

Dirac-geodesics with curvature term are Dirac-harmonic maps with curvature term from onedimensional domains. In this paper, we first describe the structure of Dirac-geodesics with curvature term in surfaces and give solutions on the unit 2-sphere and the hyperbolic plane, and then we give the structure of solutions in warped product spaces. Finally, we define the heat flow of Dirac-geodesics with curvature term and prove the global existence and sub-convergence of the heat flow into any closed surfaces and space forms. Our results provide the first examples and general existence theorems of Dirac-geodesics with curvature term.

关键词： Dirac-geodesic Dirac-harmonic map curvature heat flow existence

Mechanism of extracellular electron transport and reactive oxygen mediated Sb(Ⅲ)oxidation by Klebsiella aerogenes HC10

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Journal of Environmental Sciences 2025年第1期147卷 11-21页

作者： qun Rong Chaolan zhang Caiyuan Ling Dingtian Lu Linjiang Jiang College of Resources Environment and Materials Guangxi UniversityNanning 530004China School of Environment and Life Science Nanning Normal UniversityNanning 530001China

Microbial oxidation and the mechanism of Sb(Ⅲ)are key governing elements in biogeochemical cycling.A novel Sb oxidizing bacterium,Klebsiella aerogenes HC10,was attracted early and revealed that extracellular metabolites were the main fractions driving Sb ***,linkages between the extracellular metabolite driven Sb oxidation process and mechanism remain ***,model phenolic and quinone compounds,i.e.,anthraquinone-2,6-disulfonate(AQDS)and hydroquinone(HYD),representing extracellular oxidants secreted by *** HC10,were chosen to further study the Sb(Ⅲ)oxidation mechanism.N_(2)purging and free radical quenching showed that oxygen-induced oxidation accounted for 36.78%of Sb(Ⅲ)in the metabolite reaction system,while hydroxyl free radicals(·OH)accounted for 15.52%.·OH and H_(2)O_(2)are the main driving factors for Sb *** quenching,methanol purification and electron paramagnetic resonance(EPR)analysis revealed that·OH,superoxide radical(O_(2)^(•-))and semiquinone(SQ-•)were reactive intermediates of the phenolic induced oxidation ***-induced ROS are one of the main oxidants in *** voltammetry(CV)showed that electron transfer of quinone also mediated Sb(Ⅲ)*** of Sb(V)was scavenged by the formation of the secondary Sb(V)-bearing mineral mopungite[NaSb(OH)6]in the incubation *** study demonstrates the microbial role of oxidation detoxification and mineralization of Sb and provides scientific references for the biochemical remediation of Sb-contaminated soil.

关键词： Antimonite oxidation Active oxygen Free radical Electron transfer AQDS

Fabrication of flake-like NiCo_(2)O_(4)/reduced graphene oxide/melamine-derived carbon foam as an excellent microwave absorber

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International Journal of Minerals,Metallurgy and Materials 2025年第3期32卷 556-565页

作者： Konghu Tian Hang Yang Chao zhang Ruiwen Shu qun Shao Xiaowei Liu Kaipeng Gao The First Affiliated Hospital of Anhui University of Science and Technology(Huainan First People’s Hospital) Huainan 232001China Analysis and Test Center Anhui University of Science and TechnologyHuainan 232001China School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Carbon-based foams with a three-dimensional structure can serve as a lightweight template for the rational design and control-lable preparation of metal oxide/carbon-based composite microwave absorption *** this study,a flake-like nickel cobaltate/re-duced graphene oxide/melamine-derived carbon foam(FNC/RGO/MDCF)was successfully fabricated through a combination of solvo-thermal treatment and high-temperature *** indicated that RGO was evenly distributed in the MDCF skeleton,providing ef-fective support for the load growth of FNC on its *** S3,the FNC/RGO/MDCF composite prepared by solvothermal method for 16 h,exhibited a minimum reflection loss(RL_(min))of-66.44 dB at a thickness of 2.29 *** the thickness was reduced to 1.50 mm,the optimal effective absorption bandwidth was 3.84 *** of the absorption mechanism of FNC/RGO/MDCF revealed that its excellent absorption performance was primarily attributed to the combined effects of conduction loss,multiple reflection,scattering,in-terface polarization,and dipole polarization.

关键词： carbon foam reduced graphene oxide flake-like nickel cobaltate microwave absorbing materials

Identifying the dynamic behaviors in complete reconstruction of Co-based complex precatalysts during electrocatalytic oxygen evolution

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Journal of Energy Chemistry 2025年第1期100卷 226-233页

作者： Jingfang zhang Danyang Wu Linke Cai Youluan Lu Fanpeng Cheng Lijuan Shi qun Yi Yao Liu Yi Huang Key Laboratory of Green Chemical Engineering Process of Ministry of Education Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationHubei Key Laboratory of Novel Reactor and Green Chemical TechnologySchool of Chemical Engineering&PharmacyWuhan Institute of TechnologyWuhan 430205HubeiChina Key Laboratory of Pesticide&Chemical Biology of Ministry of Education Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction of Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079HubeiChina College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108FujianChina

Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction(OER).Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under operating conditions of OER ***,most of them undergo incomplete reconstruction with limited thickness of reconstruction layer,leading to low component utilization and arduous exploration of real catalytic ***,we identify the dynamic behaviors in complete reconstruction of Co-based complexes during *** hollow phytic acid(PA)cross-linked CoFe-based complex nanoboxes with porous nanowalls are designed because of their good electrolyte penetration and mass transport ability,in favor of the fast and complete reconstruction.A series of experiment characterizations demonstrate that the reconstruction process includes the fast substitution of PA by OH-to form Co(Fe)(OH)xand subsequent potential-driven oxidation to Co(Fe)*** obtained CoFeOOH delivers a low overpotential of 290 mV at a current density of 10 mA cm^(-2)and a long-term *** experiment results together with theory calculations reveal that the Fe incorporation can result in the electron rearrangement of reconstructed CoFeOOH and optimization of their electronic structure,accounting for the enhanced OER *** work provides new insights into complete reconstruction of metal-based complexes during OER and offers guidelines for rational design of high-performance electrocatalysts.

关键词： Complete reconstruction Co-based complex Precatalysts Oxygen evolution reaction

Deformable Perfect Vortex Wave-Front Modulation Based on Geometric Metasurface in Microwave Regime

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Chinese Journal of Electronics 2025年第1期34卷 64-72页

作者： Yueyi Yuan Wenjie Zhou Mengnuo Fan qun Wu Kuang zhang Harbin Institute of Technology

Perfect vortex(PV) beam, as a novel paradigm to carry orbital angular momentum(OAM), owns constant radius of energy intensity and infinite mode of helical patterns, which overcomes the divergence performances of conventional vortex beam. However, common approaches for PV beam generation require optical cascading systems that should constitute of various lenses and components with bulk volume and high alignment standards,also cannot realize PV customization. Thus, in this paper, we propose a general scheme based on compact platform of geometric metasurface to achieve PV beams generations and deformable wave-front modulations. The adopted unit cell is designed with “ABA”-shaped configuration, which can high-efficiently transform circular polarization incident wave into its cross-polarized state and impose required PV phase patterns. Here, we construct series of metasurface lenses to achieve PVs with eight different OAM modes at operating frequency 10 GHz, and additionally conduct quasi-elliptical energy-ring intensities and fractional modals of PVs by introducing asymmetric periodicity and extra singularities. By exploiting compact metasurface platform, this general scheme for PV beam generation and modulation would provide a theoretical foundation for the electromagnetic waves controlling in modern wireless communication systems.

关键词： Wireless communication Polarization Optical polarization Optical vortices Metasurfaces Geometrical optics Adaptive optics Optical modulation Optical beams Lenses

MMGCF: Generating Counterfactual Explanations for Molecular Property Prediction via Motif Rebuild

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Journal of Computer and Communications 2025年第1期13卷 152-168页

作者： Xiuping zhang qun Liu Rui Han Chongqing Key Laboratory of Computational Intelligence Chongqing University of Posts and Telecommunications Chongqing China College of Electronic and Information Engineering Chongqing Open University Chongqing China

Predicting molecular properties is essential for advancing for advancing drug discovery and design. Recently, Graph Neural Networks (GNNs) have gained prominence due to their ability to capture the complex structural and relational information inherent in molecular graphs. Despite their effectiveness, the “black-box” nature of GNNs remains a significant obstacle to their widespread adoption in chemistry, as it hinders interpretability and trust. In this context, several explanation methods based on factual reasoning have emerged. These methods aim to interpret the predictions made by GNNs by analyzing the key features contributing to the prediction. However, these approaches fail to answer critical questions: “How to ensure that the structure-property mapping learned by GNNs is consistent with established domain knowledge”. In this paper, we propose MMGCF, a novel counterfactual explanation framework designed specifically for the prediction of GNN-based molecular properties. MMGCF constructs a hierarchical tree structure on molecular motifs, enabling the systematic generation of counterfactuals through motif perturbations. This framework identifies causally significant motifs and elucidates their impact on model predictions, offering insights into the relationship between structural modifications and predicted properties. Our method demonstrates its effectiveness through comprehensive quantitative and qualitative evaluations of four real-world molecular datasets.

关键词： Interpretability Causal Relationship Counterfactual Explanation Molecular Graph Generation

Effects of increased seeding density on seedling characteristics,mechanical transplantation quality,and yields of rice with crop straw boards for seedling cultivation

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Journal of Integrative Agriculture 2025年第1期24卷 101-113页

作者： Yufei Ling Mengzhu Liu Yuan Feng Zhipeng Xing Hui Gao Haiyan Wei qun Hu Hongcheng zhang Research Institute of Rice Industrial Engineering Technology Yangzhou University/Jiangsu Key Laboratory of Crop Cultivation and Physiology/Jiangsu Co-Innovation Center for Modern Production Technology of Grain CropsYangzhou 2250o0China

The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice *** problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling *** study conducted field experiments from 2021 to 2022,using transplanting seedling ages of 10 and 15 days to explore the effects of 250,300,and 350 g/tray on the seedling quality,mechanical transplantation quality,yields,and economic benefits of *** commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as *** cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics,but there was no significant difference in seedling vitality compared to *** minimum number of rice trays used in the experiment was observed in the treatment of 350-10(300 g/tray and 10-day seedling age),only 152-155 trays ha^(-1),resulting in a 62%reduction in the number of trays *** increasing the seeding rate of rice,missed holes during mechanical transplantation decreased by 2.8 to 4%.The treatment of 300-15(300 g/tray and 15-day seedling age)achieved the highest yields and economic *** results indicated that using crop straw boards can reduce the application of seedling *** that basis,rice yields can be increased by raising the seeding rate and shortening the seedling age of rice without compromising seedling quality.

关键词： machine-transplanted rice crop straw board seedling rate seedling quality mechanical transplanta quality yield

Stable structures and properties of Ru_(2)Al_(5)

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Chinese Physics B 2025年第1期34卷 414-420页

作者： Jing Luo Meiguang zhang Xiaofei Jia qun Wei School of Physics Xidian UniversityXi’an 710071China College of Physics and Optoelectronic Technology Baoji University of Arts and SciencesBaoji 721016China

Novel ordered intermetallic compounds have stimulated much ***–Al alloys are a prominent class of hightemperature structural materials,but the experimentally reported crystal structure of the intermetallic Ru_(2)Al_(5) phase remains elusive and *** resolve this controversy,we extensively explored the crystal structures of Ru_(2)Al_(5) using first-principles calculations combined with crystal structure prediction *** the calculated x-ray diffraction patterns and lattice parameters of five candidate Ru2Al5structures,those of the orthorhombic Pmmn structure best aligned with recent experimental *** structural stabilities of the five Ru_(2)Al_(5)structures were confirmed through formation energy,elastic constants,and phonon spectrum *** also comprehensively analyzed the mechanical and electronic properties of the five *** work can guide the exploration of novel ordered intermetallic compounds in Ru–Al alloys.

关键词： crystal structure prediction mechanical properties first-principles calculations

Synchronization of Chaotic Intensities and Phases in an Array of N Lasers

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Communications in Theoretical Physics 2005年第2期43卷 233-239页

作者： SUNJian zhushi-qun SchoolofPhysicalScienceandTechnology SuzhouUniversitySuzhou215006China

A linear array of N mutually coupled single-mode lasers is investigated. It is shown that the intensities of N lasers are chaotically synchronized when the coupling between lasers is relatively strong. The chaotic synchronization of intensities depends on the location of the lasers in the array. The chaotic synchronization appears between two outmost lasers, the second two outmost lasers, etc. There is no synchronization between nearest neighbors of the lasers. If the number of N is odd, the middle laser is never synchronized between any lasers. The chaotic synchronization of phases between nearest lasers in the array is examined by using the analytic signal and the Gaussian filter methods based on the peak of the power spectrum of the intensity. It can be seen that the message of chaotic intensity synchronization is conveyed through the phase synchronization.

关键词： chaotic synchronization intensity phase linear array solid state lasers