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First-principle prediction of structural and mechanical properties in NbMoTaWRe_(x) refractory high-entropy alloys with experimental validation

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Rare Metals 2022年第10期41卷 3343-3350页

作者： Jin-Yong Mo Yi-Xing Wan Zhi-Bin Zhang Xin Wang Xiao-Qing Li Bao-Long Shen Xiu-Bing Liang School of Chemistry and Chemical Engineering China University of Mining and TechnologyXuzhou221116China Defense Innovation Institute Academy of Military ScienceBeijing100071China Department of Materials Science and Engineering KTH Royal Institute of Technology10044StockholmSweden School of Materials Science and Engineering Jiangsu Key Laboratory for Advanced Metallic MaterialsSoutheast UniversityNanjing211189China

In this work,the effect of Re alloying on the phase composition,crystal structure,and mechanical properties of NbMoTaWRe_(x) (x=0,0.27,0.57,0.92,1.33) refractory high-entropy alloys (RHEAs) were systematically investigated by combining the calculation of phase diagram(CALPHAD),first-principle calculations and *** theoretical predictions showed good consistency with the experimental *** the increase in Re content,the theoretical results showed that all considered alloys have a single body-centered cubic (bcc) structure and the lattice constant and ductility were decreased,while the elastic moduli and hardness were *** avoid extreme brittleness,a strategic suggestion was given for the design of Re-containing RHEAs in the future.

关键词： alloys alloying entropy

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Nonintegrability in the PXP model: A graph-theoretical approach

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Physical Review B 2025年第8期111卷 085104-085104页

作者： HaRu K. Park Department of Physics Korea Advanced Institute of Science and Technology Daejeon 34141 South Korea

Establishing a rigorous proof of integrability or nonintegrability in quantum many-body systems remains one of the most challenging tasks, as it requires demonstrating the presence or absence of local conserved quantities and deciphering the complex dynamics of the system. In this paper, we introduce a graph-theoretical approach to address this issue. This framework not only provides a comprehensive method for analyzing the nonintegrability of quantum systems but also brings advantages for integrable systems by enabling the classification of local conserved quantities through a straightforward count of isolated loops in the associated graphs. As an illustrative example, we focus on the PXP model, a system widely believed to be nonintegrable, and rigorously confirm its nonintegrability by demonstrating the absence of local conserved quantities through graph-theoretical analysis. This proof for the PXP model conveys several key insights: It not only confirms the model's nonintegrability but also indicates that the quantum many-body scarring properties of the model is not associated with local conserved quantities. Our innovative approach is broadly applicable for proving (non-)integrability in other quantum many-body systems, significantly simplifying the process and offering numerous potential applications.

关键词： Graph theory

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Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1900-1911页

作者： Kwang Tae Son Chang Hee Cho Myoung Gyun Kim Ji Woon Lee School of Mechanical Industrialand Manufacturing EngineeringOregon State UniversityCorvallis OR 97331USA Department of Materials Science Engineering Northwestern UniversityEvanston IL 60208USA Research Institute of Industrial Science and Technology(RIST) Pohang 37673Rep.of Korea Division of Advanced Materials Engineering Kongju National UniversityCheonan 31080Rep.of Korea Center for Advanced Materials and Parts of Powders Kongju National UniversityCheonan 31080Rep.of Korea

Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture *** DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥*** Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage *** 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~*** backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain ***,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX *** this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage *** texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage *** initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关键词： Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture

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Amphiphilic Block Copolymer Micelles for Gene Delivery

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Chemical Research in Chinese Universities 2022年第6期38卷 1368-1379页

作者： LI Qin JIN Bixin LUO Yunjun LI Xiaoyu School of Material Science and Engineering Beijing Institute of TechnologyBeijing100081P.R.China Key Laboratory of High Energy Density Materials Ministry of EducationBeijing Institute of TechnologyBeijing100081P.R.China Experimental Centre of Advanced Materials Beijing Institute of TechnologyBeijing100081P.R.China

Gene therapy is a promising method to treat acquired and inherited diseases by introducing exogenous genes into specific recipient *** micelles with different nanoscopic morphologies and properties hold great promise for gene delivery *** cationic polymers,poly(ethyleneimine)(PEI),poly(L-lysine)(PLL),poly(2-dimethylaminoethyl methacrylate)(PDMAEMA)and novel cationic polymers poly(2-oxazoline)s(POxs),have been incorporated into block copolymers and decorated with targeting moieties to enhance transfection *** order to minimize cytotoxicity,nonionic block copolymer micelles are utilized to load gene through hydrophilic and hydrophobic interactions or covalent conjugations,*** our perspective,properties(shape,size,and mechanical stiffness,etc.)of block copolymer micelles may significantly affect cytotoxicity,transfection efficiency,circulation time,and load capacity of gene vectors in vivo and in *** review briefly sums up recent efforts in cationic and nonionic amphiphilic polymeric micelles for gene delivery.

关键词： Polymeric micelle Block copolymer Gene delivery

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Scalable parallel photonic processing unit for various neural network accelerations

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Photonics Research 2024年第11期12卷 2691-2702页

作者： SHIYIN DU JUN ZHANG HAO OUYANG ZILONG TAO QIUQUAN YAN HAO HAO JUNHU ZHOU JIE YOU YUHUA TANG TIAN JIANG State Key Laboratory of High-Performance Computing College of ComputerNational University of Defense TechnologyChangsha 410073China National Innovation Institute of Defense Technology Academy of Military Sciences PLA ChinaBeijing 100071China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Institute for Quantum Science and Technology College of ScienceNational University of Defense TechnologyChangsha 410073China

In recent years,integrated optical processing units(IOPUs)have demonstrated advantages in energy efficiency and computational speed for neural network inference ***,limited by optical integration technology,the practicality and versatility of IOPU face serious *** this work,a scalable parallel photonic processing unit(SPPU)for various neural network accelerations based on high-speed phase modulation is proposed and implemented on a silicon-on-insulator platform,which supports parallel processing and can switch between multiple computational paradigms simply and without latency to infer different neural network structures,enabling to maximize the utility of on-chip *** SPPU adopts a scalable and process-friendly architecture design,with a preeminent photonic-core energy efficiency of 0.83 TOPS/W,two to ten times higher than existing integrated *** the proof-of-concept experiment,a convolutional neural network(CNN),a residual CNN,and a recurrent neural network(RNN)are all implemented on our photonic processor to handle multiple tasks of handwritten digit classification,signal modulation format recognition,and review emotion *** SPPU achieves multi-task parallel processing capability,serving as a promising and attractive research route to maximize the utility of on-chip components under the constraints of integrated technology,which helps to make IOPU more practical and universal.

关键词： network acceleration attractive

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Enhanced magnetic performance of Fe-rich Sm_(2)Co_(17)-type magnets by optimizing Zr content

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Journal of Materials science & technology 2024年第26期193卷 178-186页

作者： Jian Li Minxia Fang Yao Liu Xin Song Wentao Jia Junming Gou Tao Yuan Yuanchao Ji Lizhong Zhao Chen Wang Tianyu Ma Frontier Institute of Science and Technology MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matterand State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China The Southwest Applied Magnetism Research Institute Mianyang 621000China Institute of Advanced Magnetic Materials College of Materials&Environmental EngineeringHangzhou Dianzi UniversityHangzhou 310018China College of Materials Science and Engineering Fuzhou UniversityFuzhou 350002China

Despite the high theoretical energy product and low material cost of Fe-rich 2:17-type Sm-Co-Fe-Cu-Zr magnets,it is still a big challenge to simultaneously achieve high energy product and high coercivity due to damaged cellular nanostructure,*** cell boundary *** this work,both high energy product(∼30.29 MGOe)and high coercivity(∼26.24 kOe)have been achieved in Fe-rich Sm_(24.8)Co_(bal)Fe_(20.5)Cu_(5.2)Zr_(x)(x wt%)magnets through optimizing Zr *** reveals that raising Zr content from 1.5 wt%to 2.5 wt%can effectively refine the cellular nanostructure,which corresponds to an increased volume fraction of cell boundary ***,excess Zr content(*** 2.5 wt%)leads to the formation of micron-sized Zr-rich Zr_(6)Co_(23) soft magnetic particles,weakening the hard magnetic *** particular,the high Zr-content(3.5 wt%)magnet exhibits strongly inhomogeneous chemistry as well as cellular nanostructure in the vicinity of micron-sized Zr_(6)Co_(23)particles(*** distribution of cell boundary precipitates),deteriorating both squareness factor and *** a result,the optimum magnetic property combination is achieved at an intermediate Zr concentration by balancing the contradictive effects between cell refinement and soft magnetic impurities.

关键词： Permanent magnets Magnetic properties Microstructure

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Mode-locked cylindrical vector vortex beam unlocked the generation of a 2 µm multidimensional ultrafast laser

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Optics Express 2025年第6期33卷 13001-13009页

作者： Kang, Hui Xu, Tong Miao, Kairui Zhu, Qiang Yao, Tianchen Song, Xiaozhao Ma, Jiacheng Zhou, Wei Qian, Zhisheng Xie, Zhengpin Gong, Yue Wang, Haotian Xu, Xiaodong Jia, Baohua Wang, Yishan Wang, Fei Shen, Deyuan Jiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou221116 China Jiangsu Institute of Mid Infrared Laser Technology & Applications Xuzhou221000 China RMIT University MelbourneVIC3000 Australia State Key Laboratory of Ultrafast Optical Science and Technology Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an710119 China

The development of multidimensional lasers, particularly 2 µm vector vortex pulsed beams, has garnered significant interest for applications in laser medicine and optical communication. This paper reports the successful achievement of mode-locked azimuthally polarized vector beams (APVB) and radially polarized vector beams (RPVB) in a c-cut Tm:CaYAlO4 crystal cavity. Utilizing a semiconductor saturable absorber mirror (SESAM), the laser produced output powers of 110 mW (APVB) and 98 mW (RPVB), with pulse durations of 41.2 ps and 49.7 ps, and vortex topological charges of -1 and +1, respectively. This represents the first stable mode-locked states of the cylindrical vector vortex beam in a 2 µm solid-state laser. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Solid state lasers

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Improved Adaptive Wavelet Thresholding Based on Decomposition Layers for Noise Reduction

Improved Adaptive Wavelet Thresholding Based on Decompositio...

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Electronic Information Engineering and Computer Communication (EIECC), International Conference on

作者： Jun Li Zeyu Wang Jun Nie Xun Ye Shengqiang Liu Ning Zhao University of Science and Technology of China Hefei China Institute of Advanced Technology of University of Science and Technology of China Hefei China

ISBN: (数字)9798331534622

ISBN: (纸本)9798331534639

In practical application scenarios, sound acts as a vital information carrier. However, the process of sound signal acquisition is frequently perturbed by environmental interferences, causing noise to infiltrate the acquired signals. Hence, noise reduction processing becomes a pivotal aspect of signal processing. The wavelet threshold denoising method is extensively employed in the sound noise reduction realm owing to its simplicity and practicability. In this paper, by integrating the frequency traits of sound information with the characteristics of wavelet decomposition, an enhanced threshold function predicated on the wavelet decomposition layer is devised. Additionally, denoising experiments are executed by appending Gaussian noise of diverse signal-to-noise ratios (SNRs) to pristine sound signals. Concurrently, denoising experiments on speech signals gathered from real scenarios are also performed for comparative analysis. Three evaluation indices, namely SNR, mean square error (MSE), and waveform similarity, are utilized to appraise the performance. Experimental outcomes evince that within specific Gaussian noise environments, in contrast to traditional hard and soft threshold methods, the signal processed by the improved threshold function witnesses an SNR elevation ranging from 10% to 20%, an MSE diminution within 30% - 50%, and a waveform similarity augmentation between 15% and 25%, forcefully demonstrating its preeminent noise reduction prowess.

关键词： Wavelet transforms Analytical models Adaptation models Gaussian noise Noise reduction Mean square error methods Wavelet analysis Distance measurement Signal denoising Signal to noise ratio

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A Simulation Study on Magnetic Field Distribution of Two-Cells Proton Exchange Membrane Fuel Cell Stack 5th

A Simulation Study on Magnetic Field Distribution of Two-Cel...

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5th International Conference on Energy Storage and Intelligent Vehicles, ICEIV 2022

作者： Sun, Yuning Mao, Lei He, Kai Liu, Zhongyong Lu, Shouxiang Jackson, Lisa Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei230026 China Institute of Advanced Technology University of Science and Technology of China Hefei230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei230026 China School of Aeronautical and Automotive Engineering Loughborough University Loughborough United Kingdom

ISBN: (纸本)9789819910267

As the promising device in automotive, stationary, and portable applications, proton exchange membrane fuel cell (PEMFC)’s performance has attracted growing attention, which can be strongly affected by its current distribution. With the characteristic of online and nondestruction, magnetic field can be used to evaluate the current distribution and PEMFC state, while further study is still lacked for understanding the effect of PEMFC stack structure and operation conditions on its magnetic field distribution. In this study, a numerical model of two-cells PEMFC stack is established to investigate its magnetic field distributions at different current densities and states, from which the coupling effect of magnetic field of each cell is clarified. In this PEMFC stack model, the distributions of magnetic field at different states and current densities are constant while the magnitude of magnetic field will vary. Moreover, coupling effect will be weakened with the cell distance between two cells. From the results, these findings can be utilized to monitor the operation state of PEMFC stack in the further researches. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Magnetic fields

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Tailoring MgH_(2) for hydrogen storage through nanoengineering and catalysis

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Journal of Magnesium and Alloys 2022年第11期10卷 2946-2967页

作者： Zhao Ding Yuting Li Hang Yang Yangfan Lu Jun Tan Jianbo Li Qian Li Yu'an Chen Leon L.Shaw Fusheng Pan College of Materials Science and Engineering National Engineering Research Center for Magnesium AlloysChongqing UniversityChongqing 400044China The State Key Laboratory of Refractories and Metallurgy Institute of Advanced Materials and NanotechnologyWuhan University of Science and TechnologyWuhan 430081China Department of Mechanical Materials and Aerospace EngineeringIllinois Institute of TechnologyChicago 60616United States

Hydrogen energy has been recognized as “Ultimate Power Source” in the 21st century, which could be the best solution to the looming energy crisis and climate degeneration in the near future. Due to its high safety, low price, abundant resources and decent hydrogen storage density, magnesium based solid-state hydrogen storage materials are becoming the leading candidate for onboard hydrogen storage. However,the high operation temperature and slow reaction rate of MgH_(2), as a result of the large formation enthalpy and high reaction activation energy,respectively, are the first and most difficult problems we need to face and overcome to realize its industrialization. Herein, a state-of-the-art review on tailoring the stable thermodynamics and sluggish kinetics of hydrogen storage in MgH_(2), particularly through nanoengnieering and catalysis is presented, aiming to provide references and solutions for its promotion and application. Promising methods to overcome the challenges faced by MgH_(2)/Mg, such as bidirectional catalysts and nanoconfinement with in-situ catalysis are compared and the required improvements are discussed to stimulate further discussions and ideas in the rational design of MgH_(2)/Mg systems with ability for hydrogen release/uptake at lower temperatures and cycle stability in the near future.

关键词： Hydrogen storage materials MgH_(2) Nanoengineering Catalysis Hydrogen release Hydrogen uptake

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