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Enhanced Grain Refining Effect of Mg–Zr Master Alloy on Magnesium Alloys via a Synergistic Strategy Involving Heterogeneous Nucleation and Solute‑Driven Growth Restriction

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1354-1366页

作者： Gang Zeng hong Liu Jing‑Peng Xiong Jian‑long Li yong Liu Key Laboratory of Lightweight and High Strength Structural Materials of Jiangxi Province School of Advanced ManufacturingNanchang UniversityNanchang 330031China

Zirconium(Zr)emerges as the most effective grain refiner for magnesium(Mg)alloys incorporating ***,Zr is introduced in the form of an Mg–Zr master ***,within Mg–Zr master alloys,Zr predominantly exists in a particle form,which tends to aggregate due to attractive van der Waals *** clustered Zr is prone to settling,thereby reducing its refining impact on Mg *** this work,a combined pretreatment process for Mg–Zr master alloys was proposed,encompassing the introduction of a physical field to intervene the agglomeration of particle Zr and the employ of high-temperature dissolution and peritectic reactions to promote the solid solution of *** results demonstrate that the particle Zr within the pretreated Mg–Zr master alloy is effectively dispersed and refined,and greater solute Zr levels can be *** subsequent grain refinement ability was studied on a typical Mg–6Zn–0.6Zr(wt%)*** outcome highlights that an improvement in the grain refinement efficacy(32.4%)of Mg–Zr master alloys was obtained with a holding time of 60 *** pretreated Mg–Zr master alloy significantly augments the efficiency of grain refinement for Mg alloys through a synergistic strategy involving heterogeneous nucleation and solute-driven growth *** crucial factor in achieving effective grain refinement of Zr in Mg alloys lies in regulating the presence and morphology of Zr in the Mg–Zr master alloy,distinguishing between particle Zr and solute *** study introduces a novel method for developing more efficient Mg–Zr refiners.

关键词： Magnesium alloy Mg-Zr master alloy Grain refinement Heterogeneous nucleation Solute-driven growth restriction Synergistic strategy

IMTNet:Improved Multi-Task Copy-Move Forgery Detection Network with Feature Decoupling and Multi-Feature Pyramid

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Computers, Materials & Continua 2024年第9期80卷 4603-4620页

作者： Huan Wang hong Wang Zhongyuan Jiang Qing Qian yong long School of Information Guizhou University of Finance and EconomicsGuiyang550025China College of Big Data Statistics Guizhou University of Finance and EconomicsGuiyang550025China

Copy-Move Forgery Detection(CMFD)is a technique that is designed to identify image tampering and locate suspicious ***,the practicality of the CMFD is impeded by the scarcity of datasets,inadequate quality and quantity,and a narrow range of applicable *** limitations significantly restrict the capacity and applicability of *** overcome the limitations of existing methods,a novel solution called IMTNet is proposed for CMFD by employing a feature decoupling ***,this study formulates the objective task and network relationship as an optimization problem using transfer ***,it thoroughly discusses and analyzes the relationship between CMFD and deep network architecture by employing ResNet-50 during the optimization solving ***,a quantitative comparison between fine-tuning and feature decoupling is conducted to evaluate the degree of similarity between the image classification and CMFD domains by the enhanced ***,suspicious regions are localized using a feature pyramid network with bottom-up path *** results demonstrate that IMTNet achieves faster convergence,shorter training times,and favorable generalization performance compared to ***,it is shown that IMTNet significantly outperforms fine-tuning based approaches in terms of accuracy and F_(1).

关键词： Image copy-move detection feature decoupling multi-scale feature pyramids passive forensics

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-yong Huo Qiu-Shuang Yang Jiu-Jiu Chen hong-Kang Li long-Chao Yao Fu-Chun He Chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Extending Structures for Gel'fand-Dorfman Bialgebras

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Acta Mathematica Sinica,English Series 2024年第2期40卷 619-638页

作者： Jia Jia WEN Yan yong hong School of Mathematics Hangzhou Normal UniversityHangzhou 311121P.R.China

Gel'fand-Dorfman bialgebra,which is both a Lie algebra and a Novikov algebra with some compatibility condition,appeared in the study of Hamiltonian pairs in completely integrable *** also emerged in the description of a class special Lie conformal algebras called quadratic Lie conformal *** this paper,we investigate the extending structures problem for Gel'fand-Dorfman bialgebras,which is equivalent to some extending structures problem of quadratic Lie conformal ***,given a Gel'fand-Dorfman bialgebra(A,o,[.,.]),this problem is how to describe and classify all Gel'fand-Dorfman bialgebra structures on a vector space E(A⊂E)such that(A,o,[.,.])is a subalgebra of E up to an isomorphism whose restriction on A is the identity *** by the theories of extending structures for Lie algebras and Novikov algebras,we construct an object gH2(V,A)to answer the extending structures problem by introducing the notion of a unified product for Gel'fand-Dorfman bialgebras,where V is a complement of A in *** particular,we investigate the special case when dim(V)=1 in detail.

关键词： Gel'fand-Dorfman bialgebra Lie conformal algebra Extending structures problem Novikovalgebra

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1210-1220页

作者： Xiao-yong Gao hong Wei Li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

THE SECOND RECIPROCAL DERIVATIVE POTENTIOMETRIC STRIPPING ANALYSIS

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Chinese Chemical Letters 1991年第11期2卷 859-860页

作者： Xiang Yuan RUAN Ju Nan LI Jian Cheng DENG Yi Hen LI Nan JIANG yong hong long Department of Chemistry Xiangtan UniversityXiangtan 411105 Department of Physics Xiangtan UniversityXiangtan 411105 Department of Computer Science Xiangtan UniversityXiangtan

A theory of the second reciprocal derivative potentiometric stripping analysis with a mercury thin-film electrode is reported.

关键词： Cd Pb In SRD THE SECOND RECIPROCAL DERIVATIVE POTENTIOMETRIC STRIPPING ANALYSIS

Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

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Defence Technology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zhi-kai Yao Yao-wen Ge Jian-yong Yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange *** considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and *** these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become *** by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical *** approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control *** from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control *** developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output ***,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

Human pluripotent stem cell-derived kidney organoids:Current progress and challenges

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World Journal of Stem Cells 2024年第2期16卷 114-125页

作者： hong-Yan long Zu-Ping Qian Qin Lan yong-Jie Xu Jing-Jing Da Fu-Xun Yu Yan Zha Graduate School Zunyi Medical UniversityZunyi 563000Guizhou ProvinceChina Department of Laboratory Medicine Guizhou Provincial People’s HospitalGuiyang 550002Guizhou ProvinceChina Department of Nephrology Guizhou Provincial People’s HospitalGuiyang 550002Guizhou ProvinceChina Key Laboratory of Diagnosis and Treatment of Pulmonary Immune Diseases National Health CommissionGuizhou Provincial People’s HospitalGuiyang 550002Guizhou ProvinceChina

Human pluripotent stem cell(hPSC)-derived kidney organoids share similarities with the fetal ***,the current hPSC-derived kidney organoids have some limitations,including the inability to perform nephrogenesis and lack of a corticomedullary definition,uniform vascular system,and coordinated exit path-way for urinary ***,further studies are required to produce hPSC-derived kidney organoids that accurately mimic human kidneys to facilitate research on kidney development,regeneration,disease modeling,and drug *** this review,we discussed recent advances in the generation of hPSC-derived kidney organoids,how these organoids contribute to the understanding of human kidney development and research in disease ***,the limitations,future research focus,and applications of hPSC-derived kidney organoids were highlighted.

关键词： Kidney Organoids Human pluripotent stem cell Development Vascular system Disease modeling

An Accelerated Proximal Gradient Algorithm for Hankel Tensor Completion

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Journal of the Operations Research Society of China 2024年第2期12卷 461-477页

作者： Chuan-long Wang Xiong-Wei Guo Xi-hong Yan Key Laboratory of Engineering and Computational Science Shanxi Provincial Department of EducationJinzhong 030619ShanxiChina Department of Mathematics Taiyuan Normal UniversityJinzhong 030619ShanxiChina

In this paper,an accelerated proximal gradient algorithm is proposed for Hankel tensor completion *** our method,the iterative completion tensors generated by the new algorithm keep Hankel structure based on projection on the Hankel tensor ***,due to the special properties of Hankel structure,using the fast singular value thresholding operator of the mode-s unfolding of a Hankel tensor can decrease the computational ***,the convergence of the new algorithm is discussed under some reasonable ***,the numerical experiments show the effectiveness of the proposed algorithm.

关键词： Hankel tensor Tensor completion Accelerated proximal gradient algorithm