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OVERLOAD ANALYSIS OF MARKOVIAN MODELS

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Systems Science and Mathematical Sciences 1999年第3期12卷 222-230页

作者： yiqiang q. zhao(Department of Mathematics Mathematics and Statistics University of Winnipeg,Winnipeg, Manitoba, Canada R3B2E9) University of Winnipeg 加拿大

A new procedure for computing stationary probabilities for an overloadedMarkovian model is proposed in terms of the rotated Markov chain. There are two advantages to use this procedure: i) This procedure allows us to approximate an overloadedfinite model by using a stable infinite Markov chain. This will make the study easier whenthe infinite model has a simpler solution. ii) Numerically) this procedure often significantlyreduces the number of computations and the req.irement of computer memory. By usingdifferent examples, we specifically demonstrate the process of implementing this rotatingprocedure.

关键词： Markov processes q.eues, overload.

The growth ofβphase in Mg-Gd-Y-Ni alloy by experimental and first-principles study

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Journal of Magnesium and Alloys 2024年第2期12卷 506-515页

作者： yiqiang Hao Lei Zhou Zhiq.ng Chen Zhixian zhao Bin Chen School of Materials Science and Engineering Shanghai Jiao Tong University800 Dongchuan RoadShanghai200240China

The paper reports on the atomic investigation aboutβphase in Mg_(96)Gd_(2)Y_(1)Ni_(1) alloy by using the first-principles study and the high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM)corrected by atomic *** using HAADF-STEM,the rectangularβphases were observed in the underage and peak aging stages in Mg_(96)Gd_(2)Y_(1)Ni_(1) ***βphase could be precipitated from the previously precipitatedβphase,and theβphase grew in steps when it was precipitated.A special transition structure of three atomic layer thicknesses was first observed at the edge of theβphase and the structure of this interface is probably as theβ/Mg_(1) interface for the analysis of thermodynamic characterization and electronic ***β'phase and theβ_(H) structure were precipitated only at the edge of the length directions of theβ***β'phase continues to grow into aβphase directly without the formation ofβ_(1) phase,resulting in an increase in the length of theβphase,which is discovered for the first time.

关键词： HAADF-STEM First-principles study Mg-Gd-Y-Ni alloy βphase Growth Interface

Structure-regulated fluorine-containing additives to improve the performance of perovskite solar cells

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Nano Research 2024年第7期17卷 6080-6086页

作者： Peiya Chen Xiaoman Bi Hao Yan Yingjie zhao Yihao Liu Zhuo Huang q.an Xiao Yongpeng Yang Shasha Zhang yiqiang Zhang Yanlin Song Henan Institute of Advanced Technology College of ChemistrySchool of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyNational Laboratory for Molecular Sciences(BNLMS)Beijing 100190China

Perovskite solar cells(PSCs)have seen remarkable progress in recent years,largely attributed to various additives that enhance both efficiency and *** these,fluorine-containing additives have garnered significant interest because of their uniq.e hydrophobic properties,effective defect passivation,and regulation capability on the crystallization ***,a targeted structural approach to design such additives is necessary to further enhance the performance of ***,fluoroalkyl ethylene with different fluoroalkyl chain lengths(CH_(2)CH(CF_(2))nCF_(3),n=3,5,and 7)as liq.id additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect *** findings indicate that optimizing the q.antity of F groups plays a crucial role in regulating the electron cloud distribution within the additive *** optimization fosters strong hydrogen bonds and coordination effects with FA+and uncoordinated Pb^(2+),ultimately enhancing crystal q.ality and device ***,1H,1H,2H-perfluoro-1-hexene(PF_(3))with the optimal number of F presents the most effective modulation effect.A PSC utilizing PF_(3)achieves an efficiency of 24.05%,and exhibits exceptional stability against humidity and thermal *** work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.

关键词： perovskite solar cells fluorine number additive structure crystallization regulation defect passivation

Controllable selective anchoring of subnanometric Ru clusters or single-atoms/clusters on tungsten nitride for the hydrogen oxidation

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Science China Chemistry 2024年第11期67卷 3749-3756页

作者： q.jiao Sun Chuanq.ang Wu yiqiang Sun Yuan Shen Lei zhao Xiaodong Yang Li Yang Yunxiang Lin Keke Mao Kun Xu School of Chemistry and Chemical Engineering Key Laboratory of Functional Inorganic Material Chemistry of Anhui Province Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education Anhui University Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui University School of Chemistry and Chemical Engineering University of Jinan School of Energy and Environment Anhui University of Technology

The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms（SAs） into the substrate. However, the q.estion of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction（HOR） remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires（RuC/WN） show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters（NCs）-coupled catalyst anchored on WN nanowires system（RuC,S/WN）. Notably, the RuC/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 m A mg-1PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that RuC/WN owns an optimized H*and OH*reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance.

关键词： hydrogen oxidation reaction Ru cluster catalyst Ru single atoms and nanoclusters coupled catalyst tungsten nitride substrate

Observability Analysis of Integrated Electricity and Heating Systems with Thermal q.asi-dynamics in Pipelines

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： Zhigang Li Wenjian Zheng Junbo zhao J.H.Zheng q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Fuzhou Changle District Power Supply Company of State Grid Fujian Electric Power Co. Ltd.Fuzhou 350000China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06269USA CSEE IEEE

Observability analysis(OA)is vital to obtaining the available input measurements of state estimation(SE)in an integrated electricity and heating system(IEHS).Considering the thermal q.asi-dynamics in pipelines,the measurement eq.ations in heating systems are dependent on the estimated results,leading to an interdependency between OA and *** OA methods req.ire measurement eq.ations be known exactly before SE is performed,and they are not applicable to *** bridge this gap,a scenario-based OA scheme for IEHSs is devised that yields reliable analysis results for a predefined set of time-delay scenarios to cope with this *** its core procedure,the observable state identification and observability restoration are formulated in terms of integer linear *** tests are conducted to demonstrate the validity and superiority of the proposed formulation.

关键词： Integrated electricity and heating system measurement observability analysis state estimation thermal q.asi-dynamics

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表型可塑性的研究进展

科学通报 2024年第14期69卷 1881-1892页

作者：孔源杜茁赵毅强中国农业大学生物学院畜禽生物育种全国重点实验室北京100193 中国科学院遗传与发育生物学研究所北京100101

表型可塑性是指同一基因型个体在不同环境下表现不同表型的现象,或生物体为响应不同环境条件而产生不同表型的能力,是生物体的基本属性,也是适应环境的重要途径.生物体对遗传变异和环境扰动的鲁棒性则被称为渠道化,体现了生物体适应环... 详细信息

表型可塑性是指同一基因型个体在不同环境下表现不同表型的现象,或生物体为响应不同环境条件而产生不同表型的能力,是生物体的基本属性,也是适应环境的重要途径.生物体对遗传变异和环境扰动的鲁棒性则被称为渠道化,体现了生物体适应环境变化的不同策略.现代表型可塑性的研究起始于1965年,如今已成为一个热门的研究领域.为了对表型可塑性进行定量,研究者往往使用具有相同遗传背景的群体,在包含对照环境的两种以上不同环境下量化可塑性反应.经典的表型可塑性量化方法在群体或个体水平上比较表型值的差异或表型值与环境的回归斜率.随着研究的进步,目前的可塑性量化方法正在逐步完善,遗传背景、G×E等也被加入到定量策略中.表型可塑性被认为受到遗传信息和表观遗传两方面的影响,但其背后的机制仍未被阐明.同样地,表型可塑性与适应性之间的关系存在一定的争议,其意义具有高度可变性,应做到具体问题具体分析.本文系统地介绍了表型可塑性的概念、发展简史、机制、量化方法及其与适应性的关系,结合动物、植物以及微生物的例子,总结了该领域目前的研究进展与存在的问题,并对未来的发展进行展望,以期为表型可塑性的相关研究提供较为全面的参考.

关键词：表型可塑性机制量化指标渠道化

大变形压痕揭示蛛网膜-软脑膜复合结构对脑组织的力学贡献

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Acta Mechanica Sinica 2024年第5期40卷 198-208页

作者：张弛李义强赵宏伟 Key Laboratory of CNC Eq.ipment Reliability Ministry of Education Jilin University Changchun China School of Mechanical & Aerospace Engineering Jilin University Changchun China Institute of Structured and Architected Materials Liaoning Academy of Materials Shenyang China Chongq.ng Research Institute of Jilin University Chongqing China

蛛网膜-软脑膜复合结构在维持脑组织生理功能、抵御有害载荷方面发挥至关重要的作用然而,该结构的力学特性仍不明晰.本研究采用大变形动态压痕技术获取了蛛网膜-软脑膜复合结构的力学响应,通过有限元仿真分析与试验相结合,发现并归纳了... 详细信息

蛛网膜-软脑膜复合结构在维持脑组织生理功能、抵御有害载荷方面发挥至关重要的作用然而,该结构的力学特性仍不明晰.本研究采用大变形动态压痕技术获取了蛛网膜-软脑膜复合结构的力学响应,通过有限元仿真分析与试验相结合,发现并归纳了该结构在外部载荷作用下的重要的力学特性。研究结果表明,蛛网膜-软脑膜复合结构的存在可以增加大脑皮层的剪切模量和阻尼比,增强脑组织对局部变形的抵抗能力.此外,在遭受大变形时,该结构可以将大脑皮层所承受的最大应力和应变分别降低40%和53%.此外,该结构可以在脑组织松弛时阻止应变向大脑皮层传递。本研究为脑组织有限元模型的完善与蛛网膜-软脑膜复合结构的动态力学特性研究提供了基础数据.

关键词：蛛网膜软脑膜复合结构动态力学特性大脑皮层外部载荷压痕局部变形

RISC-V AES扩展指令的硅前评估与安全增强

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华中科技大学学报（自然科学版） 2024年第3期52卷 7-13页

作者：赵毅强魏鑫李尧何家骥天津大学微电子学院天津300072

针对密码算法加速的指令集架构扩展可能为处理器引入侧信道泄露的风险,提出了一种硅前阶段侧信道安全评估方法,能准确定位处理器运行过程中存在侧信道泄露风险的时刻与微架构组件.基于一款32 bit顺序精简指令集计算机(RISC-V)处理器架构... 详细信息

针对密码算法加速的指令集架构扩展可能为处理器引入侧信道泄露的风险,提出了一种硅前阶段侧信道安全评估方法,能准确定位处理器运行过程中存在侧信道泄露风险的时刻与微架构组件.基于一款32 bit顺序精简指令集计算机(RISC-V)处理器架构,实现了两种代表性的高级加密标准(AES)扩展指令与扩展硬件电路,而后应用所提出的评估方法对其开展侧信道安全评估.基于评估结果提出了扩展端口动态掩码和运算单元功耗随机化的混合防护策略,进行了硅前安全验证,最终实现了高侧信道安全的AES指令集架构扩展.实验结果表明:所提出的混合防护策略能够在4.9%的面积开销下,提升了AES扩展1 886倍以上的侧信道安全性.

关键词：硅前侧信道高级加密标准(AES) 扩展指令精简指令集计算机(RISC-V) 相关性功耗分析

Dynamic plugging regulating strategy of pipeline robot based on reinforcement learning

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Petroleum Science 2024年第1期21卷 597-608页

作者： Xing-Yuan Miao Hong zhao College of Mechanical and Transportation Engineering China University of PetroleumBeijing102249China

Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the pipeline and PIPR. In this paper, we propose a dynamic regulating strategy to reduce the plugging-induced vibration by regulating the spoiler angle and plugging velocity. Firstly, the dynamic plugging simulation and experiment are performed to study the flow field changes during dynamic plugging. And the pressure difference is proposed to evaluate the degree of flow field vibration. Secondly, the mathematical models of pressure difference with plugging states and spoiler angles are established based on the extreme learning machine (ELM) optimized by improved sparrow search algorithm (ISSA). Finally, a modified q.learning algorithm based on simulated annealing is applied to determine the optimal strategy for the spoiler angle and plugging velocity in real time. The results show that the proposed method can reduce the plugging-induced vibration by 19.9% and 32.7% on average, compared with single-regulating methods. This study can effectively ensure the stability of the plugging process.

关键词： Pipeline isolation plugging robot Plugging-induced vibration Dynamic regulating strategy Extreme learning machine Improved sparrow search algorithm Modified q.learning algorithm