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Current advances of transition metal dichalcogenides in electromagnetic wave absorption:A brief review

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International Journal of Minerals,Metallurgy and Materials 2023年第3期30卷 428-445页

作者： Shijie zhang Jiying Li Xiaotian Jin Guanglei wu School of Material Science and Engineering Henan Province Engineering Research Center of New Cermet Matrix CompositesHenan University of TechnologyZhengzhou 450001China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

Transition metal dichalcogenides(TMDs)show great advantages in electromagnetic wave(EMW)absorption due to their unique structure and electrical properties.Tremendous research works on TMD-based EMW absorbers have been conducted in the last three years,and the comprehensive and systematical summary is still a rarity.Therefore,it is of great significance to elaborate on the interaction among the morphologies,structures,phases,components,and EMW absorption performances of TMD-based absorbers.This review is devoted to analyzing TMD-based absorbers from the following perspectives:the EMW absorption regulation strategies of TMDs and the latest progress of TMD-based hybrids as EMW absorbers.The absorption mechanisms and component-performance dependency of these achievements are also summarized.Finally,a straightforward insight into industrial revolution upgrading in this promising field is proposed.

关键词： transition metal dichalcogenides phase manipulation hybrids hierarchical structure absorption mechanism

On hp refinements of independent cover numerical manifold method——some strategies and observations

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Science China(Technological Sciences) 2023年第5期66卷 1335-1351页

作者： zhang Ning ZHENG Hong LI Xu wu WenAn School of Civil Engineering Qinghai UniversityQinghai810016China Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100081China Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing100091China

In this paper,strategies are provided for a powerful numerical manifold method(NMM)with h and p refinement in analyses of elasticity and elasto-plasticity.The new NMM is based on the concept of the independent cover,which gets rid of NMM's important defect of rank deficiency when using higher-order local approximation functions.Several techniques are presented.In terms of mesh generation,a relationship between the quadtree structure and the mathematical mesh is established to allow a robust h-refinement.As to the condition number,a scaling based on the physical patch is much better than the classical scaling based on the mathematical patch;an overlapping width of 1%–10%can ensure a good condition number for 2nd,3rd,and 4th order local approximation functions;the small element issue can be overcome after the local approximation on small patch is replaced by that on a regular patch.On numerical accuracy,local approximation using complete polynomials is necessary for the optimal convergence rate.Two issues that may damage the convergence rate should be prevented.The first is to approximate the curved boundary of a higher-order element by overly few straight lines,and the second is excessive overlapping width.Finally,several refinement strategies are verified by numerical examples.

关键词： independent cover numerical manifold method hp refinement partition of unity higher order element condition number

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抗日战争时期毛泽东是如何制定国际战略的

毛泽东研究 2015年第4期 15-22页

作者：高长武中共中央文献研究室

在抗战时期国际战略的制定和调整过程中,毛泽东一直遵循并坚持运用"先谋于局、后谋于略,略从局出"的方法。抗战爆发后,毛泽东制定了对内建立抗日民族统一战线、对外建立反对日本法西斯国际统一战线,团结一切可以团结的力量打败日本帝国... 详细信息

在抗战时期国际战略的制定和调整过程中,毛泽东一直遵循并坚持运用"先谋于局、后谋于略,略从局出"的方法。抗战爆发后,毛泽东制定了对内建立抗日民族统一战线、对外建立反对日本法西斯国际统一战线,团结一切可以团结的力量打败日本帝国主义的战略;抗战进入战略相持阶段,毛泽东把国际战略的着力点放到了揭露并防范美英等国牺牲中国利益与日本媾和的阴谋,与苏联和世界人民共同建立反对战争反对侵略的统一战线上;当苏德战争、太平洋战争相继爆发,二战性质转化为世界反法西斯的正义战争之时,他又适时提出了联合苏美英等国建立世界反法西斯统一战线的主张;当世界反法西斯战争胜利曙光初显,世界两极格局初露端倪,美国对华政策由扶蒋容共转为扶蒋反共之时,他在批评美国对华政策转向的同时,提醒中国人民防止斯科比事件在中国的重演,将联合苏美英的战略实际上调整为侧重联苏的战略。

关键词：毛泽东抗日战争国际战略

Deep reinforcement learning for UAV swarm rendezvous behavior

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Journal of Systems Engineering and Electronics 2023年第2期34卷 360-373页

作者： zhang Yaozhong LI Yike wu Zhuoran XU Jialin School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710129China

The unmanned aerial vehicle(UAV)swarm technology is one of the research hotspots in recent years.With the continuous improvement of autonomous intelligence of UAV,the swarm technology of UAV will become one of the main trends of UAV development in the future.This paper studies the behavior decision-making process of UAV swarm rendezvous task based on the double deep Q network(DDQN)algorithm.We design a guided reward function to effectively solve the problem of algorithm convergence caused by the sparse return problem in deep reinforcement learning(DRL)for the long period task.We also propose the concept of temporary storage area,optimizing the memory playback unit of the traditional DDQN algorithm,improving the convergence speed of the algorithm,and speeding up the training process of the algorithm.Different from traditional task environment,this paper establishes a continuous state-space task environment model to improve the authentication process of UAV task environment.Based on the DDQN algorithm,the collaborative tasks of UAV swarm in different task scenarios are trained.The experimental results validate that the DDQN algorithm is efficient in terms of training UAV swarm to complete the given collaborative tasks while meeting the requirements of UAV swarm for centralization and autonomy,and improving the intelligence of UAV swarm collaborative task execution.The simulation results show that after training,the proposed UAV swarm can carry out the rendezvous task well,and the success rate of the mission reaches 90%.

关键词： double deep Q network(DDQN)algorithms unmanned aerial vehicle(UAV)swarm task decision deep reinforcement learning(DRL) sparse returns

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基于被动视觉的窄间隙管道焊熔池特征分析

热加工工艺 2024年第9期53卷 18-22页

作者：谢忠奇丁超吴涛张旺郭彦兵上海电机学院机械学院上海201306 中国核工业第五建设有限公司上海201512

在窄间隙管道焊接过程中,传统主动视觉激光受限于窄间隙坡口的几何特征无法投射到工件坡口处,且焊缝易被焊丝遮挡无法获取焊缝特征,无法进行焊接质量在线判定。本文通过被动视觉直接获取熔池图像,采用中值滤波降噪、Canny边缘检测、面... 详细信息

在窄间隙管道焊接过程中,传统主动视觉激光受限于窄间隙坡口的几何特征无法投射到工件坡口处,且焊缝易被焊丝遮挡无法获取焊缝特征,无法进行焊接质量在线判定。本文通过被动视觉直接获取熔池图像,采用中值滤波降噪、Canny边缘检测、面积滤波筛选、圆拟合手段还原窄间隙焊接熔池的完整轮廓,提取了用来表征熔池轮廓的曲率半径和前进角两个特征参数。管道焊接实验结果表明,焊接电流越大,熔池轮廓曲率半径和前进角越大。分析了熔透状态下的特征参数范围,为后续参数调整提供依据。

关键词：窄间隙焊接被动视觉图像处理熔池特征

Stable expression and control parameters in the numerical simulation of unsaturated flow

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1501-1514页

作者： Zhiyuan zhang Xu LI Yongkang wu Xiaokang LI Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The Richards’equation describes the flow phenomenon in unsaturated porous media and is essential to hydrology and environmental science.This study evaluated the numerical stability of two different forms of the Richards’equation.Sensitivity analyses were performed to investigate the control parameters of the equation.The results show that the h-form Richards’equation has better applicability for calculating variable saturation flows than theθ-form Richards’equation.For the h-form Richards’equation,the hydraulic conductivity of the soil in the low-suction range and the specific moisture capacity in the high-suction range primarily influenced the solution.In addition,sensitivity analyses indicated that the saturated hydraulic conductivity,initial condition,and air-entry pressure have a higher sensitivity to the simulation results than the saturated water content,rainfall intensity,and decline rate of hydraulic conductivity.Moreover,their correctness needs to be guaranteed first in numerical simulations.The research findings can provide a helpful reference for improving the reliability of numerical simulations of unsaturated flows.

关键词： Richards’equation sensitivity analysis unsaturated soil hydraulic diffusivity seepage simulation

基层医务人员突发公共卫生事件韧性评价指标体系的构建

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中国健康教育 2024年第6期40卷 531-537+574页

作者：吴巧慧许军吴霖健刘莉刘琛方浩庭张金华南方医科大学公共卫生学院南方医科大学南方医院广东石油化工学院

目的筛选并构建科学有效的基层医务人员突发公共卫生事件韧性评价体系。方法通过文献阅读法确定备选的指标,采用Delphi专家咨询法对备选指标进行3轮专家意见的征询,然后对筛选后的指标进行第4轮专家征询,最后采用属性层次分析法对韧... 详细信息

目的筛选并构建科学有效的基层医务人员突发公共卫生事件韧性评价体系。方法通过文献阅读法确定备选的指标,采用Delphi专家咨询法对备选指标进行3轮专家意见的征询,然后对筛选后的指标进行第4轮专家征询,最后采用属性层次分析法对韧性评价指标体系赋予权重。共有25名专家参与Delphi法专家咨询。结果本研究所邀请的专家涉足近8个学科领域,平均专业年限15.69。前3轮征询专家一致性系数Kendall's W分别为0.372,0.409和0.394。建立了3个层级的指标体系:一级指标为基层医务人员的职业素养(权重0.346)、心理资本(权重0.614)和应急态度(权重0.040),二级指标有13个内容,进一步细分为46个三级指标。结论 Delphi法结合属性层次分析法用于基层医务人员突发公共卫生事件韧性评估指标体系的筛选是有效可行的。构建的基层医务人员韧性评估体系能系统地评估基层医务人员面对突发公共卫生事件时所具备的韧性,可为提高基层医疗单位的突发公共卫生事件应对能力提供策略依据。

关键词：基层医务人员韧性公共卫生事件 Delphi法属性层次分析法

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阿尔茨海默病外周血新型生物标志物研究进展

中华神经医学杂志 2024年第5期23卷 513-519页

作者：张丹丹任国强吴晶魏伟李学忠陈晓鹏江苏大学附属人民医院神经内科镇江江苏大学附属人民医院放射科镇江

阿尔茨海默病(AD)是一种神经退行性疾病, 主要表现为进行性记忆缺陷和认知功能下降。既往关于AD外周血生物标志物的研究多集中于病理标志物如β-淀粉样蛋白(Aβ)和磷酸化tau蛋白(p-tau)的改变上。本文围绕近几年AD外周血新型生物标志物... 详细信息

阿尔茨海默病(AD)是一种神经退行性疾病, 主要表现为进行性记忆缺陷和认知功能下降。既往关于AD外周血生物标志物的研究多集中于病理标志物如β-淀粉样蛋白(Aβ)和磷酸化tau蛋白(p-tau)的改变上。本文围绕近几年AD外周血新型生物标志物如炎性因子、代谢指标、非编码RNA等的研究进展进行综述, 以期为AD的诊断提供参考。

关键词：阿尔茨海默病外周血新型生物标志物

Extraction and separation of yttrium from other rare earths in chloride medium by phosphorylcarboxylic acids

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Journal of Rare Earths 2022年第6期40卷 958-964,I0004页

作者： Guolong wu Zhifeng zhang Yanling Li wuping Liao State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China University of Science and Technology of China Hefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

Two phosphorylcarboxylic acids,3-((bis(2-ethylhexyloxy))phosphoryl)propanoic acid(PPA) and 3-((bis(2-ethylhexyloxy))phosphoryl)-3-phenylpropanoic acid(PPPA),were synthesized for separating yttrium from other rare earths in the chloride feed of ion-adsorption type rare earth concentrate.The effect of the factors such as pH_(1/2),temperature,saponification degree and phase modifiers was investigated.The separation efficiencies of PPA and PPPA are obviously better than the typical extractants such as sec-octylphenoxy acetic acid(CA-12) and naphthenic acid(NA).The extraction process of rare earths by PPA and PPPA is a cation exchanging reaction,which is similar to those of CA-12 and NA.The loaded rare earths in both PPA and PPPA systems can be effectively back-extracted by 0.5 mol/L HCl or higher concentration.A cascade extraction process for separating yttrium from other rare earths was developed using PPPA as the extractant.The yttrium product with the purity of 97.20 wt% was obtained by 35 stages of extraction and 12 stages of scrubbing.

关键词： Phosphorylcarboxylic acids Extraction Separation Yttrium Chloride Ion-adsorption type rare earth concentrate