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Precipitation on stacking faults in Mg–9.8wt%Sn alloy

Journal of Materials Science & Technology 2020年第10期42卷 230-240页

作者： c.q.liu c.He H.W.chen J.F.Nie International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing UniversityChongqing400044China Department of Materials Science and Engineering Monash UniversityVictoria3800Australia Electron Microscopy center Chongqing UniversityChongqing400044PR China

In this work,we have systematically investigated precipitation ofβ’-Mg3Sn phase on intrinsic stacking faults I1 and I2 in a Mg-9.8 wt%Sn alloy using aberration-corrected scanning transmission electron *** observed I1 faults are generated by the dissociation of c+a perfect dislocations and bounded by Frank partial dislocations having a Shockley *** ofβ’on I1 involves a shear of 1/3α,similar to its formation directly from theα-Mg ***β’phase often nucleates at one end of an I1 fault due to the interaction between shear strain fields ofβ’and the Shockley component of the Frank partial at that end,and subsequently grows towards the other end of the *** theβ’reaches to the other end,the Shockley partial bounding the lengthening end of theβ’reacts with the Frank partial bounding the fault,generating an a perfect dislocation that can glide away from the precipitate and the *** observed I2 faults are generated by the dissociation of a perfect dislocations and bounded by Shockley *** ofβ’on I2 does not need a shear of 1/3α,since the pre-existing I2 fault already provides an ABcA four-layer structure ofβ’.Thickening of theβ’that has already formed on the I2 involves the successive occurrence of three crystallographically equivalent shears of 1/3αon every second(0002)αplane of theα-Mg *** this thickening mechanism is similar to that of theβ’formed directly from theα-Mg matrix,an a perfect dislocation will be produced when theβ’is thickened to eight layers,and it can again glide away from the precipitate and the fault.

关键词： Heterogeneous precipitation HAADF-STEM Shockley partial dislocation Frank partial dislocation Dislocation reaction

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Response surface methodology for optimizing the fermentation medium of alpha-galactosidase in solid-state fermentation

Response surface methodology for optimizing the fermentation...

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饲用酶制剂开发与应用技术交流研讨会

作者： c.q.liu,q.H.chen,B.Tang,H.Ruan and G.q.He Department of Food Science and Nutrition,Zhejiang University,Hangzhou 310029,china

Aims:Alpha-galactosidase is applied in food and feed industries for hydrolysing raffinose series oligosaccharides(RO) that are the factors primarily responsible for flatulence upon ingestion of soybean-derived *** objective of the current work was to develop an optimal culture medium for the production of alpha-galactosidase in solid-state fermentation(SSF) by a mutant strain Aspergillus foetidus. Methods and Results:Response surface methodology(RSM) was applied to evaluate the effects of variables,namely the concentrations of wheat bran,soybean meal,KHPO,MnSO·HO and cuSO·5HO on alpha-galactosidase production in the solid substrate.A fractional factorial design(FFD) was firstly used to isolate the main factors that affected the production of alpha-galactosidase and the central composite experimental design(ccD) was then adopted to derive a statistical model for optimizing the composition of the fermentation *** experimental results showed that the optimum fermentation medium for alpha-galactosidase production by Aspergillus foetidus ZU-G1 was composed of 8-2137 g wheat bran,1·7843 g soybean meal,0·001 g MnSO·HO and 0·001 g cuSO·5HO in 10 g dry matter fermentation medium. conclusions:After incubating 96 h in the optimum fermentation medium, alpha-galactosidase activity was predicted to be 2210·76 U g dry matter in 250 ml shake *** the present study,alpha-galactosidase activity reached 2207·19 U g dry matter. Significance and Impact of the Study:Optimization of the solid substrate was a very important measure to increase enzyme activity and realize industrial production of *** process of alpha-galactosidase production in laboratory scale may have the potential to scale-up.

关键词： alpha-galactosidase Aspergillus foetidus medium optimization response surface methodology solid-state fermentation

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Response surface methodology for optimizing the fermentation medium of alpha-galactosidase in solid-state fermentation

Response surface methodology for optimizing the fermentation...

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中国食品科学技术学会第五届年会暨第四届东西方食品业高层论坛

作者： c.q.liu q.H.chen B.Tang H.Ruan G.q.He (Department of Food Science and Nutrition,Zhejiang University,Hangzhou 310029,china)

Aims:Alpha-galactosidase is applied in food and feed industries for hydrolysing raffinose series oligosaccharides(RO)that are the factors primarily responsible for flatulence upon ingestion of soybean-derived *** objective of the current work was to develop an optimal culture medium for the production of alpha-galactosidase in solid-state fermentation(SSF) by a mutant strain Aspergillus foetidus.,Methods and Results:Response surface methodology (RSM)was applied to evaluate the effects of variables,namely the concentrations of wheat bran, soybean meal,KHPO,MnSO·HO and cuSO·5HO on alpha-galactosidase production in the solid substrate.A fractional factorial design(FFD)was firstly used to isolate the main factors that affected the production of alpha-galactosidase and the central composite experimental design (ccD)was then adopted to derive a statistical model for optimizing the composition of the fermentation *** experimental results showed that the optimum fermentation medium for alpha-galactosidase production by Aspergillus foetidus ZU-Gl was composed of 8.2137 g wheat bran,1.7843 g soybean meal,0.001 g MnSO·HO and 0.001 g cuSO·5HO in 10g dry matter fermentation medium.,conclusions:After incubating 96 h in the optimum fermentation medium,alpha-galactosidase activity was predicted to be 2210·76 U gdry matter in 250 ml shake *** the present study,alpha-galactosidase activity reached 2207·19 U gdry matter. Significance and Impact of the Study:Optimization of the solid substrate was a very important measure to increase enzyme activity and realize industrial production of *** process of alpha-galactosidase production in laboratory scale may have the potential to scale-up.

关键词： alpha-galactosidase Aspergillus foetidus medium optimization response surface methodology solid-state fermentation.

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Anomalous open orbits in Hofstadter spectrum of chern insulator

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Science china(Physics,Mechanics & Astronomy) 2025年第3期Mechanics & Astronomy) .卷 143-148页

作者： Haijiao Ji Peng Zhou Noah F.q.Yuan Hua Jiang Haiwen liu X.c.Xie center for Advanced quantum Studies Department of Physics Beijing Normal University Tsung-Dao Lee Institute Shanghai Jiao Tong University Department of Mathematics UC Berkeley Institute for Nanoelectronic Devices and quantum computing Fudan University International center for quantum Materials School of Physics Peking University Hefei National Laboratory

The nontrivial band topology of chern insulator can enrich the content of its Hofstadter butterfly spectra, which is closely related to recent experiments in twisted bilayer graphene and cold atom systems. We investigate the Hofstadter spectrum for various models of chern insulators under a rational flux φ0/q, here φ0=h/e and q being an integer. We find the number of splitting subbands is |q-c| with c denoting the chern number of parent band. Importantly, anomalous open-orbital subbands with chern numbers q-1 and-q-1 emerge unexpectedly, which are beyond the parameter window（-q/2, q/2） of the Diophantine equation studied by Thouless-Kohmoto-Nightingale-den Nijs [Phys. Rev. Lett. 49, 405（1982）]. The emergence of anomalous open orbits can be traced by analyzing the evolution of the Hofstadter spectrum, identifying as a new type of topological phase transition. These novel findings not only pinpoint the peculiar Hofstadter spectrum of chern insulator, but also provide routes to study exotic characteristics beyond the Landau level physics.

关键词： Hofstadter spectrum topological phase transition open orbit

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Estimating Transient Stability Regions of Large-scale Power Systems Part Ⅱ: Reduced-order Stability Region with computational Efficiency

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cSEE Journal of Power and Energy Systems 2025年第1期11卷 38-50页

作者： Yuqing Lin Tianhao Wen Lei chen Yang liu q. H. Wu School of Electric Power Engineering South China University of TechnologyGuangzhou510640China

Part Ⅱ of this paper presents a reduced-order stability region (ROSR) based method to estimate the full-order stability region (FOSR) of a large-scale power system. First, we introduce the definitions of FOSR and ROSR, followed by a comprehensive theory that reveals the relationships between them. Since the full-order system can be rewritten as a standard two timescale model and the reduced-order system is regarded as the slow subsystem of it, the proposed theory is derived based on the idea of singular perturbation. With rigorous mathematical proof, the properties of FOSR and ROSR are revealed. Moreover, a modified Energy Augmented Dynamic (EAD) algorithm and a constrained equidistant projection (cEP) approach are employed to estimate the ROSR and FOSR, respectively. The modified EAD algorithm and cEP form a so-called reduced-order stability region mapping (ROSRM) method. Finally, the proposed ROSRM method is applied to the IEEE 10-machine-39-bus power system, and simulation studies confirm its superiority to the traditional energy function method in terms of computational speed and reliability of results.

关键词： Large-scale power system singular perturbation theory stability region sum of squares transient stability

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Estimating Transient Stability Regions of Large-Scale Power Systems Part I: Koopman Operator and Reduced-Order Model

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cSEE Journal of Power and Energy Systems 2025年第1期11卷 24-37页

作者： Yuqing Lin Tianhao Wen Lei chen q. H. Wu Yang liu School of Electric Power Engineering South China University of Technology Guangzhou China

This paper presents an estimation of transient stability regions for large-scale power systems. In Part I, a Koopman operator based model reduction (KOMR) method is proposed to derive a low-order dynamical model with reasonable accuracy for transient stability analysis of large-scale power systems. Unlike traditional reduction methods based on linearized models, the proposed method does not require linearization, but captures dominant modes of the original nonlinear dynamics by employing a Koopman operator defined in an infinite-dimensional observable space. combined with the Galerkin projection, the obtained dominant Koopman eigenvalues and modes produce a reduced-order nonlinear model. To approximate the Koopman operator with sufficient accuracy, we introduce a Polynomial-based Multi-trajectory Kernel Dynamic Mode Decomposition (PMK-DMD) algorithm, which outperforms traditional DMD in various scenarios. In the end, the proposed method is applied to the IEEE 10-machine-39-bus power system and IEEE 16-machine-68-bus power system, which demonstrates that our method is significantly superior to the modal analysis method in both qualitative and quantitative aspects.

关键词： Power system stability Reduced order systems Nonlinear dynamical systems Eigenvalues and eigenfunctions Power system dynamics Kernel Transient analysis Analytical models Accuracy Modal analysis

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Edge supercurrent in Josephson junctions based on topological materials

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Science china(Physics,Mechanics & Astronomy) 2025年第2期68卷 1-12页

作者： Junjie qi chui-Zhen chen Juntao Song Jie liu Ke He qing-Feng Sun X.c.Xie Beijing Academy of quantum Information Sciences Beijing 100193China School of Physical Science and Technology Soochow UniversitySuzhou 215006China Institute for Advanced Study Soochow UniversitySuzhou 215006China college of Physics and Hebei Advanced Thin Films Laboratory Hebei Normal UniversityShijiazhuang 050024China School of Physics Xi’an Jiaotong UniversityMinistry of Education Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed MatterXi’an 710049China State Key Laboratory of Low Dimensional quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Frontier Science center for quantum Information Beijing 100084China Hefei National Laboratory Hefei 230088China International center for quantum Materials School of PhysicsPeking UniversityBeijing 100871China Interdisciplinary center for Theoretical Physics and Information Sciences Fudan UniversityShanghai 200433China

The interplay between novel topological states and superconductivity has garnered substantial interest due to its potential for topological quantum *** Josephson effect serves as a useful probe for edge superconductivity in these hybrid topological *** Josephson junctions based on topological materials,supercurrents exhibit unique quantum interference patterns,including the conventional Fraunhofer oscillations,theΦ_(0)-periodic oscillation,and the 2Φ_(0)-periodic oscillation in response to the external magnetic field(Φ_(0)=h/2e is the flux quantum,h the Planck constant,and e the electron charge).These interference patterns stem from varied Andreev reflection mechanisms and the associated current density *** review seeks to comprehensively examine the theoretical and experimental advancements in understanding the quantum interference patterns of edge supercurrents in Josephson junctions based on quantum spin Hall,quantum Hall,and quantum anomalous Hall systems.

关键词： quantum Hall effect quantum spin Hall effect quantum anomalous Hall effect Josephson junction edge supercurrent Andreev reflection

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Rational modulation of fluorophosphate cathode by anionic groups to reduce the polarization behavior for fast-charging sodium-ion batteries

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Journal of Energy chemistry 2025年第1期100卷 509-521页

作者： Xinyuan Wang Fan Zhang Xingyu Zhou qian Wang changyu liu Yangyang liu Hui Wang Xiaojie liu Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi’an 710127ShaanxiChina

Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific *** functional theory (DFT) and finite element simulations show that incorporating SO_(4)^(2-)into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge ***,the average Na+diffusion coefficient of Na_(3)V_(2)(PO_(4))_(1.95)(SO_(4))_(0.05)O_(2)F(VPS-1) is roughly double that of VP,leading to enhanced rate capability (80 c,75.5 mAh g^(-1)) and cycling stability (111.0 mAh g^(-1)capacity after 1000 cycles at 10 c current density) for ***-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 *** assembled VPS-1//SbSn/NPc full cell demonstrated stable cycling over 200 cycles at a high 5 c current,maintaining an average coulombic efficiency of 95.35%.

关键词： Anionic group modulation Polarization behavior Fast-charging Sodium-ion battery Fluorophosphate cathode

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construction of iron manganese metal-organic framework-derived manganese ferrite/carbon-modified graphene composites toward broadband and efficient electromagnetic dissipation

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International Journal of Minerals,Metallurgy and Materials 2025年第3期32卷 546-555页

作者： Baohua liu Shuai liu Zaigang Luo Ruiwen Shu School of chemical and Blasting Engineering Anhui Province Key Laboratory of Specialty PolymersAnhui University of Science and TechnologyHuainan 232001China Joint National-Local Engineering Research centre for Safe and Precise coal Mining Anhui University of Science and TechnologyHuainan 232001China

The preparation of carbon-based electromagnetic wave(EMW)absorbers possessing thin matching thickness,wide absorption bandwidth,strong absorption intensity,and low filling ratio remains a huge ***-organic frameworks(MOFs)are ideal self-sacrificing templates for the construction of carbon-based EMW *** this work,bimetallic FeMn-MOF-derived MnFe_(2)O_(4)/c/graphene composites were fabricated via a two-step route of solvothermal reaction and the following pyrolysis *** results re-veal the evolution of the microscopic morphology of carbon skeletons from loofah-like to octahedral and then to polyhedron and pomegran-ate after the adjustment of the Fe^(3+)to Mn^(2+)molar ***,at the Fe^(3+)to Mn^(2+)molar ratio of 2:1,the obtained MnFe_(2)O_(4)/c/graphene composite exhibited the highest EMW absorption ***,a minimum reflection loss of-72.7 dB and a max-imum effective absorption bandwidth of 5.1 GHz were achieved at a low filling ratio of 10wt%.In addition,the possible EMW absorp-tion mechanism of MnFe_(2)O_(4)/c/graphene composites was ***,the results of this work will contribute to the construction of broadband and efficient carbon-based EMW absorbers derived from MOFs.

关键词： metal-organic frameworks graphene magnetic composites morphology regulation electromagnetic dissipation

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Exhumation and Preservation of the Yangchuling Porphyry W-Mo Deposit in the Jiangnan Tungsten Ore Belt,South china:Insights from(U-Th)/He and Fission Track Dating

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Journal of Earth Science 2025年第1期36卷 46-56页

作者： Yue Sun Ying Wang Jianzhang Pang Samuel c.Boone Minting Wu chongjian Shao Wei liu Jiangxi Provincial Key Laboratory of Genesis and Prospect for Strategic Minerals School of Earth ScienceEast China University of TechnologyNanchang330013China Institute of Geology china Earthquake Administration Beijing100029China School of Geography Earth and Atmospheric Sciences The University of MelbourneMelbourneVIC3010Australia Department of Earth Sciences The University of AdelaideAdelaideSA5005Australia Jiangxi Duchang JinDing Tungsten cO. Ltd.Jiujiang332611China

The Yangchuling porphyry W-Mo deposit(YPWD),located in the Jiangnan porphyryskarn tungsten ore belt,is one of the most important and large-scale porphyry W-Mo deposits in South *** previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling WMo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at~150–144 Ma,their post emplacement history remains poorly understood,making their preservation status at depth *** this paper,new zircon and apatite(U-Th)/He and apatite fission track(ZHe,AHe and AFT,respectively)data of one hornfels and five intrusive rocks from a 1000-meter borehole are ***,together with new inverse thermal history models and previous geochronological data,help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo *** general,ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation,ranging from 133 to 73Ma and 67 to 25 Ma,*** four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2±0.7 to 12.6±0.5μ*** history modelling indicates that the Yangchuling ore district experienced slow,monotonic cooling since the ***-depth relationships are interpreted as recording~3.7±0.8 km of cretaceous-recent exhumation in response to regional extension throughout South china thought to have been driven by subduction retreat of the Paleo-Pacific *** of estimated net exhumation and previous metallogenic depth of~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to~1.3±0.8 km relative to Earth surface in the YPWD *** of the YPWD is attributed to the limited amount of regional denudation during the Late cretaceous and cenozoic.

关键词： (U-Th)/He fission track ore preservation thermochronology Yangchuling porphyry W-Mo deposit

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