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Taxonomic dependency and spatial heterogeneity in assembly mechanisms of bacteria across complex coastal waters

Ecological Processes 2024年第1期13卷 80-97页

作者： Huizhen Yan Dandan Lin Gaoke Gu Yujie Huang Xuya Hu Zhenhao Yu Dandi Hou Demin Zhang Barbara J.Campbell Kai Wang State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of agro-Products School of Marine SciencesNingbo University Key Laboratory of Marine Biotechnology of Zhejiang Province School of Marine Sciences Ningbo University Department of Biological sciences Clemson University

Background Understanding community assembly mechanisms across taxa and space is fundamental for microbial ecology. However, the variability and determinants of assembly processes over taxa and space remain unclear. Here, we investigated taxonomic dependency and spatial heterogeneity in bacterial assembly mechanisms across coastal waters in the East China Sea using neutral and null models with customized visualization *** Overall, bacterial assembly mechanisms varied across broad taxonomic groups(phyla and proteobacterial classes) and space at the regional scale. A determinism–stochasticity balanced mechanism governed total bacterial assembly, while taxonomic dependency existed in assembly mechanisms and ecological processes. Among community ecological features, niche breadth and negative-to-positive cohesion ratio were strongly associated with the determinism-to-stochasticity ratio of bacterial groups. Bacterial assembly mechanisms commonly exhibited spatial heterogeneity, the extent and determinants of which varied across taxonomic groups. Spatial assembly of total bacteria was directly driven by many environmental factors and potential interactions between taxa, but not directly by geographic factors. Overall, the bacterial groups with higher spatial heterogeneity in assembly mechanisms were more related to environmental and/or geographic factors(except Bacteroidetes), while those with lower heterogeneity were more related to ecological *** Our results confirm the pervasiveness of taxonomic dependency and spatial heterogeneity in bacterial assembly, providing a finer understanding about regulation across complex coastal waters.

关键词： Bacterioplankton Assembly mechanism Niche breadth Null model Environmental gradient Biogeography

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Diophantine equations and Fermat's last theorem for multivariate(skew-)polynomials

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 159-173页

作者： PAN Jie JIA Yu-ming LI Fang school of Mathematical sciences Zhejiang UniversityHangzhou 310058China Henan Experimental high school Zhengzhou 450003China

Fermat’s Last Theorem is a famous theorem in number theory which is diﬃcult to ***,it is known that the version of polynomials with one variable of Fermat’s Last Theorem over C can be proved very *** aim of this paper is to study the similar problems about Fermat’s Last Theorem for multivariate(skew)-polynomials with any characteristic.

关键词： Fermat's last theorem polynomial ring skew polynomial ring

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Magnetic Switching Dynamics and Tunnel Magnetoresistance Effect Based on Spin-Splitting Noncollinear Antiferromagnet Mn_(3)Pt

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Chinese Physics Letters 2024年第4期41卷 132-138页

作者：朱蒙董建艇李新录郑凡星周晔吴琨张佳 school of Physics and Wuhan national high Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China

In comparison to ferromagnets,antiferromagnets are believed to have superior advantages for applications in next-generation magnetic storage devices,including fast spin dynamics,vanishing stray fields and robust against external magnetic field,***,unlike ferromagnetic orders,which could be detected through tunneling magnetoresistance effect in magnetic tunnel junctions,the antiferromagnetic order(i.e.,Néel vector)cannot be effectively detected by the similar mechanism due to the spin degeneracy of conventional *** discovered spin-splitting noncollinear antiferromagnets,such as Mn_(3)Pt with momentum-dependent spin polarization due to their special magnetic space group,make it possible to achieve remarkable tunneling magnetoresistance effects in noncollinear antiferromagnetic tunnel *** first-principles calculations,we demonstrate that the tunneling magnetoresistance ratio can reach more than 800% in Mn_(3)Pt/perovskite oxides/Mn_(3)Pt antiferromagnetic tunnel *** also reveal the switching dynamics of Mn_(3)Pt thin film under magnetic fields using atomistic spin dynamic *** study provides a reliable method for detecting Néel vector of noncollinear antiferromagnets through the tunnel magnetoresistance effect and may pave its way for potential applications in antiferromagnetic memory devices.

关键词： tunneling magnetoresistance momentum

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Deciphering the role of rGO in tuning dielectric properties of Er_(2)O_(3)/ZnO/rGO nanocomposites synthesized via facile approach

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Journal of Rare Earths 2024年第3期42卷 578-585,I0006页

作者： Saiqa Hafeez Saima Perveen Muhammad Zarrar Khan Awab Hashmi Fahad Azad school of Natural sciences(SNS) National University of Sciences and Technology(NUST)IslamabadPakistan Electronic and Magnetic Materials Laboratory School of Chemical and Materials Engineering(SCME)National University of Sciences and Technology(NUST)IslamabadPakistan

The present research investigated the effect of reduced graphene oxide(rGO) integration with assynthesized Er_(2)O_(3)/ZnO nanocomposites on dielectric properties. The samples were characterized by Xray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), diffuse reflectance spectroscopy(DRS), and energy dispersive spectroscopy(EDS). Complex impedance spectroscopy was utilized to characterize dielectric relaxation phenomena in Er_(2)O_(3)/ZnO and Er_(2)O_(3)/ZnO/rGO nanocomposites. All the samples exhibit single relaxation phenomena which are ascribed to grain boundaries. The addition of rGO to Er_(2)O_(3)/ZnO nanocomposite results in the enhancement of dielectric response due to increased local field intensity caused by the formation of conductinginsulating interfaces. Furthermore, the AC conductivity of the Er_(2)O_(3)/ZnO/rGO is increased at higher frequencies due to the presence of free charge carriers in rGO. At higher frequencies, Er_(2)O_(3)/ZnO/rGO nanocomposite with increased concentration of ZnO exhibits a more stable dielectric constant with extremely low dielectric loss. Hence, the inclusion of rGO in Er_(2)O_(3)/ZnO nanocomposites makes it a novel prospective candidate in the field of energy storage devices.

关键词： Erbium oxide(Er_(2)O_(3)) Rare earths Stable dielectric constant Impedance Polarization Grain boundaries

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Observation of parabolic electron bands on superconductor LaRu2As2

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Chinese Physics B 2024年第7期33卷 70-75页

作者：周兴泰李更潘禄禄陈子超李萌时延昊杨海涛高鸿钧 Beijing national Center for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences school of Physical sciences University of Chinese Academy of Sciences Hefei national Laboratory

Ru-based superconductor LaRu2As2has been discovered exhibiting the highest critical temperature of ～ 7.8 K among iron-free transition metal pnictides with the ThCr2Si2-type crystal structure. However, microscopic research on this novel superconducting material is still lacking. Here, we utilize scanning tunneling microscopy/spectroscopy to uncover the superconductivity and surface structure of LaRu2As2. Two distinct terminating surfaces are identified on the cleaved crystals, namely, the As surface and the La surface. Atomic missing line defects are observed on the La surface. Both surfaces exhibit a superconducting gap of ～ 1.0 me V. By employing quasiparticle interference techniques, we observe standing wave patterns near the line defects on the La atomic plane. These patterns are attributed to quasiparticle scattering from two electron type parabolic bands.

关键词： superconductivity line defect quasi-particle scattering electron band

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Rediscovery of numerical Lüscher's formula from the neural network

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Chinese Physics C 2024年第7期48卷 38-44页

作者：陆宇王一佳陈莹吴佳俊 school of Physical sciences University of Chinese Academy of SciencesBeijing 100049China Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China

We present that by predicting the spectrum in discrete space from the phase shift in continuous space,the neural network can remarkably reproduce the numerical Lüscher's formula to a high *** model-independent property of the Lüscher's formula is naturally realized by the generalizability of the neural *** exhibits the great potential of the neural network to extract model-independent relation between model-dependent quantities,and this data-driven approach could greatly facilitate the discovery of the physical principles underneath the intricate data.

关键词： Luescher's formula neural network finite volume effects LQCD

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Recycling of spent lithium-ion batteries to resynthesize high-performance cathode materials for sodium-ion storage

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Tungsten 2024年第3期6卷 574-584页

作者： Hai-Qiang Gong Xing-Yuan Wang Long Ye Bao Zhang Xing Ou national Engineering Laboratory for high-Efficiency Recovery of Refractory Nonferrous Metals School of Metallurgy and Environment Central South University

The spent lithium-ion batteries recovery has been brought into focus widely for its environmental imperatives and potential profits from the metal components,such as lithium,cobalt,nickel and ***,the weaker pollution and fewer profits of LiMn2O4cathode dispel the enthusiasm and responsibility of industry ***,a simplified and efncient method to regenerate the sodium-ion cathode materials and separate Li from spent LiMn2O4materials for the profit improvement is *** detail,adjusting the parameters of carbothermal reduction process appropriately,the LiMn2O4spinel structure is destroyed within a short period time and transformed into simple metal *** anticipated,nearly 95 wt.%lithium can be obtained and recovered during the water leaching,while 99 wt.% of manganese can be extracted in acid *** that the leaching residue can return to the carbothermic reduction,leading to a closed-loop economic recycling *** regenerated Na0.67Ni0.3Mn0.7O2cathode displays excellent electrochemical performance with superior cycling stability(the initial capacity reaches 95.9 mAh·g-1,and the retention rate reached 98.3% after 100 cycles at 1 C).The delicate strategy of sodium-ion cathode material regenerated from spent LiMn2O4aims to realize lithium separation and material utilization of manganese simultaneously,providing the instructive suggestion to rise up the recycling profits of spent batteries.

关键词： Manganese Spent battery LiMn 2 O 4 cathode Recycling Regenerated Na 0.67 Ni 0.3 Mn 0.7 O 2 Sodium-ion storage

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Two-dimensional MOF-based materials:Preparations and applications as electrodes in Li-ion batteries

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Journal of Energy Chemistry 2024年第10期97卷 388-418页

作者： Narges Nobakht Seyyed Ahmad Etghani Mohammad Hosseini Seyed Hamed Aboutalebi Condensed Matter national Laboratory Institute for Research in Fundamental Sciences Batt Scout Company school of Biological sciences Institute for Research in Fundamental Sciences

Two-dimensional(2D) metal-organic frameworks(MOFs) are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable *** promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium ***,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy *** limitations have therefore warranted ongoing research to enhance the performance of 2D *** the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF *** promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical ***,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be *** hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium *** the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid *** synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in *** comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.

关键词： 2D materials 2D metal-organic frameworks Energy storage Li-ion batteries Synthesis

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Refined symmetry-resolved Page curve and charged black holes

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Chinese Physics C 2024年第5期48卷 134-140页

作者：李磐凌意 Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China school of Physics University of Chinese Academy of SciencesBeijing 100049China

The Page curve plotted using the typical random state approximation is not applicable to a system with conserved quantities,such as the evaporation process of a charged black hole,during which the electric charge does not macroscopically radiate out with a uniform *** this context,the symmetry-resolved entanglement entropy may play a significant role in describing the entanglement structure of such a *** attempt to impose constraints on microscopic quantum states to match the macroscopic phenomenon of charge radiation during black hole ***,we consider a simple qubit system with conserved spin/charge serving as a toy model for the evaporation of charged black *** propose refined rules for selecting a random state with conserved quantities to simulate the distribution of charges during the different stages of evaporation and obtain refined Page curves that exhibit distinct features in contrast to the original Page *** find that the refined Page curve may have a different Page time and exhibit asymmetric behavior on both sides of the Page *** refined Page curves may provide a more realistic description for the entanglement between the charged black hole and radiation during the evaporation process.

关键词： quantum entanglement Page curve charged black hole black hole evaporation Hawking radiation Schwinger effect random state average entropy

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Effect of Low-temperature Imidization on Properties and Aggregation Structures of Polyimide Films with Different Rigidity

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Chinese Journal of Polymer Science 2024年第8期42卷 1134-1146页

作者： Yan Jia Lei Zhai Song Mo Yi Liu Li-Xin Liu Xin-Yu Du Min-Hui He Lin Fan Key Laboratory of Science and Technology on high-tech Polymer Materials Institute of ChemistryChinese Academy of SciencesBeijing 100190China school of Chemical sciences University of Chinese Academy of SciencesBeijing 100049China

The traditional high-temperature preparation process of polyimide can cause many problems and limits the wider application in extreme *** important challenge to be solved urgently is the reduction of imidization *** this work,twelve kinds of polyimide films with different chain rigidity were prepared at low temperature of 200℃,in the absence or presence of imidazole used as the *** molecular rigidity and free volume were theoretically calculated,and relationship between structure and properties were systematically *** results show that imidization reaction under low temperatures is significantly affected by the rigidity of molecula r *** rigid structure of polyimide is not conducive to the low-temperature imidization,but this adverse effect can be eliminated by adding catalyst,resulting the notably increased imidization *** optical and thermal properties can be improved to a certain extent for the chemically catalyzed system,resulting in relatively higher heat resistance and thermal *** the mechanical performance could be determined by com plicating factors,greatly different from polyimide films prepa red by high temperature *** investigate aggregation structures of film s,the effect of chain rigidity and catalyst on the stacking or orientation of molecular chains was further *** wo rk can contribute to the understanding of chemically catalyzed imidization that is rarely reported in the existing research,and will provide guidance for the low-temperature preparation of high-performance polyimides.

关键词： Polyimide Imidization Catalyst Structure and properties Aggregation structures

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