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Data-based neural controls for an unknown continuous-time multi-input system with integral reinforcement

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CONTROL THEORY AND TECHNOLOGY 2025年第1期23卷 118-130页

作者： lv, Yongfeng Zhao, jun Zhang, Wan Chang, Huimin Taiyuan Univ Technol Coll Elect & Power Engn Taiyuan 030024 Shanxi Peoples R China Shandong Univ Sci & Technol Coll Transportat Qingdao 266590 Shandong Peoples R China Shanxi Univ Sch Math Sci Taiyuan 030006 Shanxi Peoples R China

Integral reinforcement learning (IRL) is an effective tool for solving optimal control problems of nonlinear systems, and it has been widely utilized in optimal controller design for solving discrete-time nonlinearity. However, solving the Hamilton-Jacobi-Bellman (HJB) equations for nonlinear systems requires precise and complicated dynamics. Moreover, the research and application of IRL in continuous-time (CT) systems must be further improved. To develop the IRL of a CT nonlinear system, a data-based adaptive neural dynamic programming (ANDP) method is proposed to investigate the optimal control problem of uncertain CT multi-input systems such that the knowledge of the dynamics in the HJB equation is unnecessary. First, the multi-input model is approximated using a neural network (NN), which can be utilized to design an integral reinforcement signal. Subsequently, two criterion networks and one action network are constructed based on the integral reinforcement signal. A nonzero-sum Nash equilibrium can be reached by learning the optimal strategies of the multi-input model. In this scheme, the NN weights are constantly updated using an adaptive algorithm. The weight convergence and the system stability are analyzed in detail. The optimal control problem of a multi-input nonlinear CT system is effectively solved using the ANDP scheme, and the results are verified by a simulation study.

关键词： Adaptive dynamic programming Integral reinforcement Neural networks Heuristic dynamic programming Multi-input system

Failure mechanisms of AlGaN/GaN HEMTs irradiated by high-energy heavy ions with and without bias

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Nuclear Science and Techniques 2025年第1期36卷 49-58页

作者： Pei-Pei Hu Li-jun Xu sheng-Xia Zhang Peng-Fei Zhai Ling lv Xiao-Yu Yan Zong-Zhen Li Yan-Rong Cao Xue-Feng Zheng Jian Zeng Yuan He Jie Liu Institute of Modern Physics Chinese Academy of Sciences(CAS)Lanzhou 730000China Key Laboratory of Wide Band‑gap Semiconductor Materials Ministry of EducationXidian UniversityXi’an 710071China University of Chinese Academy of Sciences(UCAS) Beijing 100049China

Gallium nitride(GaN)-based devices have significant potential for space ***,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains *** study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(HEMTs).Under a high voltage,the HEMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the *** addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect ***,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without *** latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN ***,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel *** accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and *** study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.

关键词： GaN HEMTs Heavy ions Single-event burnout Latent tracks Degradation

A nuclide identification method ofγspectrum and model building based on the transformer

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Nuclear Science and Techniques 2025年第1期36卷 80-93页

作者： Fei Li Chu-Yang Luo Ying-Zi Wen sheng lv Feng Cheng Guo-Qiang Zeng Jian-Feng Jiang Bing-Hai Li College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610000China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu 610000China Department of Physics Universitat Politècnica de CatalunyaBarcelona 08028Spain Airborne Survey and Remote Sensing Center of Nuclear Industry Shijiazhuang 050000China Hebei Key Laboratory of Airborne Detection and Remote Sensing Technology Shijiazhuang 050000China

In current neural network algorithms for nuclide identification in high-background,poor-resolution detectors,traditional network paradigms including back-propagation networks,convolutional neural networks,recurrent neural networks,etc.,have been limited in research on γ spectrum analysis because of their inherent mathematical *** is difficult to make progress in terms of training data requirements and prediction *** contrast to traditional network paradigms,network models based on the transformer structure have the characteristics of parallel computing,position encoding,and deep stacking,which have enabled good performance in natural language processing tasks in recent ***,in this paper,a transformer-based neural network (TBNN) model is proposed to achieve nuclide identification for the first ***,the Geant4 program was used to generate the basic single-nuclide energy spectrum through Monte Carlo simulations.A multi-nuclide energy spectrum database was established for neural network training using random matrices of γ-ray energy,activity,and *** on the encoder–decoder structure,a network topology based on the transformer was built,transforming the 1024-channel energy spectrum data into a 32×32 energy spectrum sequence as the model *** experiments and adjustments of model parameters,including the learning rate of the TBNN model,number of attention heads,and number of network stacking layers,the overall recognition rate reached 98.7%.Additionally,this database was used for training AI models such as back-propagation networks,convolutional neural networks,residual networks,and long shortterm memory neural networks,with overall recognition rates of 92.8%,95.3%,96.3%,and 96.6%,*** indicates that the TBNN model exhibited better nuclide identification among these AI models,providing an important reference and theoretical basis for the practical application of transformers in the qualitative and quantitativ

关键词： Nuclide identification Neural network Transformer

Effect of h-BN rods on high-temperature properties of alumina-carbon refractory

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Journal of Iron and Steel Research International 2025年第1期32卷 115-128页

作者： Ya-ge Li Shuai-bing Wu Feng Liang Zhong Huang Tu Long Long Dong jun-yi lv Hong-juan Duan Biao Wen Yong Liu Hai-jun Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Sinosteel Luoyang Institute of Refractories Research Co. Ltd.Luoyang471039HenanChina

h-BN rods modified low-carbon alumina-carbon(Al_(2)O_(3)-C)refractories were prepared,and the effect of h-BN rod addition on the high-temperature properties was investigated and compared with commercial h-BN flake,carbon black,and carbon nanotubes *** results demonstrated that Al_(2)O_(3)-C refractories containing h-BN rods exhibited optimal high-temperature service performances,including 25%higher hot modulus of rupture,21.3%higher thermal shock strength residual ratio,20.9%lower in oxidation and 44.3%less in slag corrosion,compared to the counterpart specimens without ***,benefiting from the synergistic enhancement of the rod-like h-BN and in-situ generated SiC whiskers,the high-temperature service performances of h-BN rods containing specimens outperformed counterpart specimens containing commercial h-BN flake,carbon black,and carbon nanotubes,respectively.

关键词： Al_(2)O_(3)-C refractory h-BN rod Microstructure High-temperature service performance

Flow behavior and dynamic softening mechanism of Pt−10Ir precious alloy

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中国有色金属学报 2025年第1期35卷 225-242页

作者： Xin-pei ZHANG jun-jie HE Lin PI Quan FU Wen-yan ZHOU jun CHENG sheng-wen BAI Xuan ZHOU Yi LIU Yong MAO Materials Genome Institute School of Materials and EnergyYunnan UniversityKunming 650091China Kunming Precious Materials&Technology Co. Ltd.Yunnan Precious Metals Laboratory Co.Ltd.Sino-Platinum Metals Co.Ltd.Kunming 650106China Kunming Institute of Precious Metals Kunming 650106China State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-Platinum Metals Co.Ltd.Kunming 650106China Shaanxi Key Laboratory of Biomedical Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The hot deformation behavior of Pt−10Ir alloy was studied under a wide range of deformation *** a low deformation temperature(950−1150℃),the softening mechanism is primarily dynamic *** addition,dynamic recrystallization by progressive lattice rotation near grain boundaries(DRX by LRGBs)and microshear bands assisted dynamic recrystallization(MSBs assisted DRX)coordinate the ***,it is difficult for the dynamic softening to offset the stain hardening due to a limited amount of DRXed *** a high deformation temperature(1250−1350℃),three main DRX mechanisms associated with strain rates occur:DRX by LRGBs,DRX by a homogeneous increase in misorientation(HIM)and geometric DRX(GDRX).With increasing strain,DRX by LRGBs is enhanced gradually under high strain rates;the“pinch-off”effect is enhanced at low strain rates,which was conducive to the formation of a uniform and fine microstructure.

关键词： platinum alloy hot deformation microstructure evolution dynamic recovery dynamic recrystallization

Transient chemical-mediated epigenetic modulation confers unrestricted lineage potential on human primed pluripotent stem cells

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Science China Life Sciences 2025年

作者： Shi Chen Yuanyuan He Lejun lv Bei Liu Cheng Li Hongkui Deng jun Xu Department of Cell Biology School of Basic Medical Sciences Peking University Stem Cell Research Center Peking University Health Science Center Peking University Academy of Advanced Interdisciplinary Studies Peking University BeiCell Therapeutics School of Life Sciences Center for Bioinformatics Center for Statistical Science Peking University MOE Engineering Research Center of Regenerative Medicine School of Basic Medical Sciences State Key Laboratory of Natural and Biomimetic Drugs Peking University Health Science Center and the MOE Key Laboratory of Cell Proliferation and Differentiation College of Life Sciences Peking-Tsinghua Center for Life Sciences Peking University

Human primed pluripotent stem cells are capable of generating all the embryonic ***,their extraembryonic trophectoderm potentials are *** remains unclear how to expand their developmental potential to trophectoderm *** we show that transient treatment with a cocktail of small molecule epigenetic modulators imparts trophectoderm lineage potentials to human primed pluripotent stem cells while preserving their embryonic *** chemically treated cells can generate trophectoderm-like cells and downstream trophoblast stem cells,diverging into syncytiotrophoblast and extravillous trophoblast *** and CUT&Tag analyses reveal that these induced cells share transcriptional profiles with in vivo trophectoderm and cytotrophoblast,and exhibit reduced H3K27me3 modification at gene loci specific to trophoblast lineages compared with primed pluripotent *** exploration highlighted the critical roles of epigenetic modulators HDAC2,EZH1/2,and KDM5s in the activation of trophoblast lineage *** findings demonstrate that transient epigenetic resetting activates unrestricted lineage potential in human primed pluripotent stem cells,and offer new mechanistic insights into human trophoblast lineage specification and in vitro models for studying placental development and related disorders.

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No-touch recipient hepatectomy in liver transplantation for liver malignancies: A state-of-the-art review

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Hepatobiliary & Pancreatic Diseases International 2025年第1期24卷 39-44页

作者： sheng-jun Xu Qiang Wei Xin Hu Chang-Biao Li Zhe Yang Shu-Sen Zheng Xiao Xu NHC Key Laboratory of Combined Multi-organ Transplantation Institute of Organ Transplantation Zhejiang University School of Clinical Medicine Hangzhou Medical College General Surgery Cancer Center Department of Gastrointestinal and Pancreatic Surgery Zhejiang Provincial People’s Hospital Affiliated People’s HospitalHangzhou Medical College Department of Hepatobiliary and Pancreatic Surgery Department of Liver Transplantation Shulan(Hangzhou)Hospital Zhejiang Shuren University School of Medicine Institute of Translational Medicine Zhejiang University

Tumor recurrence, the Gordian knot of liver transplantation for malignancies, may be attributed to many parameters. The technique of the “classical” recipient hepatectomy is believed to be one of the potential reasons to cause tumor evasion because of the possible increase of circulating tumor cells, thus leading to an increased recurrent rate. On this background, the no-touch oncological recipient hepatectomy technique has been developed. A comprehensive review of the development and the key surgical steps of the no-touch recipient hepatectomy is presented. This technique might improve clinical outcomes, especially for those recipients who are at a high risk for tumor recurrence. Multicenter prospective studies should be set up to further validate the prognostic role of this technique in patients with liver cancer treated with liver transplantation.

关键词： Liver transplantation Hepatocellular cancer Tumor recurrence Surgical technique No-touch recipient hepatectomy Vena cave sparing hepatectomy

An integrated photocatalytic redox architecture for simultaneous overall conversion of CO_(2)and H_(2)O toward CH_(4)and H_(2)O_(2)

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Science Bulletin 2025年第3期70卷 373-382页

作者： Muhammad Salman Nasir Bowen sheng Ying Zhao Haotian Ye jun Song Jinglin Li Ping Wang Tao Wang Xinqiang Wang Zhen Huang Baowen Zhou Key Laboratory for Power Machinery and Engineering of Ministry of Education Research Center for Renewable Synthetic FuelSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsNano-Optoelectronics Frontier Center of Ministry of Education(NFC-MOE)Peking UniversityBeijing 100871China Department of Mining and Materials Engineering McGill UniversityMontrealH3A 0G4Canada Electron Microscopy Laboratory School of PhysicsPeking UniversityBeijing 100871China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China Collaborative Innovation Center of Quantum Matter School of PhysicsPeking UniversityBeijing 100871China

Solar-driven overall conversion of CO_(2)and H_(2)O into fuels and chemicals shows an ultimate strategy for carbon neutrality yet remains a huge ***,an integrated photocatalytic redox architecture of Zn NPs/GaN Nanowires(NWs)/Si is explored for light-driven overall conversion of CO_(2)and H_(2)O into CH_(4)and H_(2)O_(2)simultaneously without any external sacrificial agents and *** as-designed architecture affords a benchmark CH_(4)activity of 189 mmol gcat^(-1)h^(-1)with a high selectivity of 93.6%,in the synchronized formation of H_(2)O_(2)at a considerable rate of 25 m g^(-1)h^(-1).Moreover,a considerable turnover number of 27,280 mol CH_(4)per mol Zn was achieved over a long-term operation of 80 *** operando spectroscopic characterizations,isotope experiments,and density functional theory calculations,it is unraveled that Zn sites are synergetic with GaN to drive CO_(2)-to-CH_(4)conversion with a lowered energy barrier of 0.27 eV while inhibiting hydrogen evolution reaction with a relatively high energy barrier of 0.93 ***,owing to the unique surface properties of GaN,water is split into*OH and*H,followed by the formation of H_(2)O_(2)because of the alleviated adsorption strength of*OH by Zn ***,the hierarchical architecture enables the achievement of high activity and high selectivity of CH_(4)from CO_(2)reduction in distilled water along with the generation of H_(2)O_(2).This work provides an integrated photocatalytic redox architecture for the synchronized production of CH_(4)and H_(2)O_(2)with the only inputs of CO_(2),distilled water,and light.

关键词： Zn nanoparticles GaN nanowires/Si Integrated redox architecture Artificial photosynthesis CH_(4)and H_(2)0_(2)

Development and validation of a nomogram prediction model for overall survival in patients with rectal cancer

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World Journal of Gastrointestinal Oncology 2025年第2期17卷 93-104页

作者： Ling Liang Xiao-sheng Li Ze-jun Huang Zu-Hai Hu Qian-Jie Xu Yu-Liang Yuan Wei Zhang Hai-Ke Lei Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment Chongqing University Cancer HospitalChongqing 400030China Chongqing Cancer Multiomics Big Data Application Engineering Research Center Chongqing University Cancer HospitalChongqing 400030China Department of Health Statistics School of Public HealthChongqing Medical UniversityChongqing 400016China

BACKGROUND Rectal cancer is prevalent and associated with substantial morbidity and *** To develop a nomogram prediction model for overall survival(OS)in patients with rectal cancer by leveraging a comprehensive analysis of demographic,clinicopathological,haematological,and follow-up data to identify independent prognostic *** We conducted a prospective cohort study in China involving rectal cancer patients and applied Cox regression and least absolute shrinkage and selection operator regression to assess the significance of various variables as independent prognostic factors for *** identified factors were integrated into a nomogram model,which was evaluated for predictive accuracy via the C-index,area under the curve(AUC),calibration curve,and decision curve analysis(DCA).RESULTS Multivariate analysis revealed independent predictors of OS,including the Karnofsky performance status,age,sex,TNM stage,chemotherapy,surgery,targeted therapy,β2-microglobulin,lactate dehydrogenase,and the neutrophil-to-lymphocyte *** nomogram demonstrated a C-index of 0.80 for the training and validation cohorts,with AUC values indicating high predictive accuracy for 1-year,3-year,and 5-year *** calibration curves confirmed the model's excellent agreement with the observed survival rates,and DCA revealed the superior clinical utility of the nomogram over the TNM staging *** In this study,a novel prognostic model that accurately predicts the OS of rectal cancer patients was *** model exhibited excellent discriminatory and calibration capabilities,thus offering a reliable tool for health care professionals to estimate patient survival.

关键词： Rectal cancer Overall survival Nomogram Prognosis