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Journal of Iron and Steel Research International 2024年第4期31卷 790-796页

作者： Ming Zhong Dong Hu da-ming guo Somnath Basu Cong Wang Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Department of Metallurgical Engineering and Materials Science Indian Institute of Technology BombayMumbai 400076MaharashtraIndia

Ferrite features in the simulated transition zone welded with CaF_(2)-SiO_(2)-MnO fluxes containing various MnO contents have been *** laser scanning microscopy has been applied to simulate the thermal cycling of the transition zone and the phase transformations during cooling have been in-situ *** has been found that the appearance temperature for ferrite side plate decreases with increasing Mn content in the weld metals caused by MnO content ***,growth rates for both ferrite side plate and acicular ferrite are significantly enhanced with a higher Mn content of weld ***,from the statistical fractions of salient microstructures,for all samples,the acicular ferrite,grain boundary ferrite,and polygonal ferrite take over more than 90%.It has also been demonstrated that with the increase in Mn content,the ferrite side plate fraction increases slightly from 5%to 10%and the acicular ferrite fraction shows a tendency of first increasing and then decreasing,which experiences the maximum with the flux containing 30 wt.%*** phenomenon is believed to be controlled by the O and Mn contents in weld metals synergistically.

关键词： Submerged arc welding Transition zone Phase transformation Microstructure

Attaining synergetic equilibrium of electrical conductivity and tensile strength in GQDs@GN/Cu composites through multi-scale intragranular and intergranular reinforcements

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Rare Metals 2024年第1期43卷 366-379页

作者： Shuang-Yin Zhang Liang Liu Rui Bao Jian-Hong Yi Sheng-da guo Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and TechnologyKunming 650093China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China

The configuration and quality of reinforcements, as well as the robustness of interfacial bonding,holding a critical significance in determining the concurrence between electrical conductivity and mechanical strength in metal matrix composites. In this study, citric acid was employed as the precursor for synthesizing multiscale carbon nanomaterials(graphene quantum dots and graphene, abbreviated as GQDs and GN). The GQDs@GN/Cu composites were fabricated through a segmented ball milling process in conjunction with subsequent spark plasma sintering(SPS). The intragranular GQDs and intergranular GQDs@GN had synergistically reinforced Cu composites through Orowan strengthening, load transfer strengthening and refinement strengthening. Furthermore,the robust interface bonding between GQDs@GN and Cu effectively mitigated interfacial impedance stemming from electron-boundary scattering. The yield strength and ultimate tensile strength of the GQDs@GN/Cu composites were recorded as 270 and 314 MPa, respectively, representing an improvement of 92 and 28% over pure Cu, while maintaining electrical conductivity at a level comparable to that of pure Cu. This study advances the understanding of the possibility of realizing a synergistic compatibility between electrical conductivity and mechanical strength in Cu composites.

关键词： Cu matrix composites Interface bonding Mechanical property Graphene quantum dots(GQDs) Electrical conductivity

The jasmonate pathway promotes nodule symbiosis and suppresses host plant defense in Medicago truncatula

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Molecular Plant 2024年第8期17卷 1183-1203页

作者： da guo Jingrui Li Peng Liu Yuzhan Wang Na Cao Xiangling Fang Tao Wang Jiangli Dong College of Biological Sciences China Agricultural UniversityBejing 100193China State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBejing 100193China state Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of Pastoral Agricuture Science and TechnologyLanzhou UniversityLanzhou730020China

Root nodule symbiosis(RNs)between legumes and rhizobia is a major source of nitrogen in agricultural *** symbiosis requires precise regulation of plant defense *** role of the defense hormone jasmonic acid(JA)in the immune response has been extensively *** research shows that JA can play either a positive or negative regulatory role in RNS depending on its concentration,but the molecular mechanisms remain to be *** this study,we found that inoculation with the rhizobia Sm1021 induces the JA pathway in Medicago truncatula,and blocking the JA pathway significantly reduces the number of infection *** in the MtMYc2 gene,which encodes a JA signaling master transcription factor,significantly inhibited rhizobia infection,terminal differentiation,and symbiotic cell *** RNA sequencing and chromatin immunoprecipitation sequencing,we discovered that MtMYc2 regulates the expression of nodule-specific MtDNF2,MtNAD1,and MtSymCRK to suppress host defense,while it activates MtDNF1 expression to regulate the maturation of MtNCRs,which in turn promotes bacteroid *** importantly,MtMYC2 participates in symbiotic signal transduction by promoting the expression of ***,the MtMYC2-MtiPD3 transcriptional regulatory module is specifically present in legumes,and the Mtmyc2 mutants are susceptible to the infection by the pathogen Rhizoctonia ***,these findings reveal the molecular mechanisms of how the JA pathway regulates RNS,broadening our understanding of the roles of JA in plant-microbe interactions.

关键词： jasmonic acid MYC2 symbiosis defense Medicago truncatula

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豆科植物特异SnRK1调控共生固氮的机制

科学通报 2024年第2期69卷 137-139页

作者：郭达刘鹏董江丽王涛中国农业大学生物学院北京100193

豆科植物和根瘤菌之间的共生固氮(symbiotic nitrogen fixation,SNF)是高度耗能的代谢过程,植物每获取1 g固定的氮(N2)需要消耗5.2~18.8 g的碳源[1].尽管这一行为互利于双方,但共生固氮的有效进行依赖于豆科植物持续的碳源供应[2].豆科... 详细信息

豆科植物和根瘤菌之间的共生固氮(symbiotic nitrogen fixation,SNF)是高度耗能的代谢过程,植物每获取1 g固定的氮(N2)需要消耗5.2~18.8 g的碳源[1].尽管这一行为互利于双方,但共生固氮的有效进行依赖于豆科植物持续的碳源供应[2].豆科新型能量感受器GmNAS1/GmNAP1的发现,为设计高效利用作物周围环境中的碳源、提高共生固氮能力提供了理论支撑[3].然而,豆科植物在缺氮时如何分配能量和碳源实现高耗能共生固氮的分子机制尚不清楚[4].豆科植物是否有独特的能量感受器参与这一过程是科学家们一直探究的问题.

关键词：豆科植物共生固氮周围环境 NAP1 感受器根瘤菌代谢过程高效利用

Theory and verification of moiréfringes for x-ray three-phase grating interferometer

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Chinese Physics B 2024年第5期33卷 532-540页

作者：单雨征葛永帅杨君郭大育蔡学宝刘晓珂侯晓文郭金川 Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education Key Laboratory of Optoelectronic Devices and Systems of the Department of EducationGuangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Research Center for Medical Artificial Intelligence Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Institute of Advanced Science Facilities Shenzhen 518107China Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China College of Biophotonics South China Normal UniversityGuangzhou 510631China MinFound Medical Systems Co. Ltd.Hangzhou 310018China

Dual-phase and three-phase grating x-ray interference is a promising new technique for grating-based x-ray differential phase contrast ***-phase grating interferometers have been relatively completely studied and *** this paper,the corresponding imaging fringe formula of the three-phase grating interferometer is *** the same time,the similarities and differences between the three-phase grating interferometer and the dual-phase grating interferometer are investigated and verified,and that the three-phase grating interferometer can produce large-period moiréfringes without using the analyzing grating is demonstrated ***,a simple method of designing three-phase grating and multi-grating imaging systems from geometric optics based on the thin-lens theory of gratings is *** theoretical formulas and experimental results provide optimization tools for designing three-phase grating interferometer systems.

关键词： x-ray phase contrast phase grating moiréfringe

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新技术时代职业世界变革与高职教育应对

高等工程教育研究 2024年第2期 145-149,173页

作者：郭达邢少乐天津职业技术师范大学世界技能大赛中国研究中心天津职业技术师范大学教育学院

高职教育的发展与职业世界的变革具有动态适应关系。新技术深刻塑造职业世界,导致宏观层面职业种类的更替、中观层面职业形式的自由化、微观层面职业性质的数字化,这对高职教育的专业动态调整机制、社会培训服务功能、人才培养方式的革... 详细信息

高职教育的发展与职业世界的变革具有动态适应关系。新技术深刻塑造职业世界,导致宏观层面职业种类的更替、中观层面职业形式的自由化、微观层面职业性质的数字化,这对高职教育的专业动态调整机制、社会培训服务功能、人才培养方式的革新提出了新挑战。对此,高职教育应遵循职业种类更替规律,健全专业动态调整机制;把握职业形式的自由化特征,促进社会培训服务功能弹性化升级;顺应职业性质演变的数字化趋势,推动人才培养方式数字化转型,从而有效地为职业世界培养高素质职业人。

关键词：职业世界高职教育新技术职业种类职业形式职业性质

人工智能的“技能—任务—职业”三重替代效应下职业教育人才培养的根本转型

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教育与职业 2024年第6期1054卷 54-61页

作者：郭达尹晨曦天津职业技术师范大学世界技能大赛中国研究中心天津职业技术师范大学职业教育学院天津300222

人工智能重塑了人类的技能、工作任务乃至整个职业,形成了“技能—任务—职业”三重替代效应。为了适应人工智能的“三重替代”效应,直接面对劳动市场和职业变迁的职业教育人才培养需进行根本转型。一是适应工业时代向智能时代转型的新... 详细信息

人工智能重塑了人类的技能、工作任务乃至整个职业,形成了“技能—任务—职业”三重替代效应。为了适应人工智能的“三重替代”效应,直接面对劳动市场和职业变迁的职业教育人才培养需进行根本转型。一是适应工业时代向智能时代转型的新需求,将培养“工具人”的教育理念转变为培养具有创造性的人。二是应对“三重替代”效应的冲击,动态调整人才类型的供给结构。三是适应人工智能对职业教育实践的新要求,通过变革传统课堂中教师、教法和教材三要素,逐步形成由具备人工智能素养的教师、具备人工智能技术特性的教法和开发囊括人工智能不易替代的关键技能内容的教材所构成的新课堂。

关键词：人工智能技能替代任务替代职业替代职业教育人才培养

企业与高职院校跨界合作的框架要素、障碍与进路——基于企业边界跨越视角的分析

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职教论坛 2024年第5期40卷 104-112页

作者：郭达尹晨曦天津职业技术师范大学世界技能大赛中国研究中心天津300350 天津职业技术师范大学职业教育学院天津300350

跨界性是职业教育的本质属性,职业教育的跨界性在实践活动层面主要表现为企业与高职院校之间的跨界合作。由于企业和高职院校分属于经济场域和教育场域两类具有不同性质的组织,从企业角度来看,校企合作是一个企业跨越自身组织边界,并调... 详细信息

跨界性是职业教育的本质属性,职业教育的跨界性在实践活动层面主要表现为企业与高职院校之间的跨界合作。由于企业和高职院校分属于经济场域和教育场域两类具有不同性质的组织,从企业角度来看,校企合作是一个企业跨越自身组织边界,并调动自身边界内的关键要素与高职院校边界内的关键要素产生联系、发生互动的一个过程。基于企业边界跨越的视角,在明晰企业边界内涵的基础上,勾勒了校企跨界合作的框架及其要素,同时结合校企跨界合作的现实状况,剖析了两者跨界合作过程中存在的政策障碍、能力障碍、制度障碍、资源障碍、利益障碍,并针对上述障碍提出了有效化解的措施,以期推动企业与高职院校跨界开展深度合作。

关键词：校企合作跨界性企业高职院校边界

基于MK的实数公理系统相容性和范畴性的Coq形式化

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控制理论与应用 2024年第7期41卷 1274-1285页

作者：郭达凯冷姝锟窦国威陈思郁文生北京邮电大学电子工程学院天地互联与融合北京市重点实验室北京100876

数学定理机器证明是人工智能基础理论的深刻体现.实数理论是数学分析的基础,实数公理系统是建立实数理论的重要方法.Morse-Kelley公理化集合论(MK)作为现代数学的基础,也为实数构建提供了严谨的数学框架和工具.本文使用定理证明器Coq,基... 详细信息

数学定理机器证明是人工智能基础理论的深刻体现.实数理论是数学分析的基础,实数公理系统是建立实数理论的重要方法.Morse-Kelley公理化集合论(MK)作为现代数学的基础,也为实数构建提供了严谨的数学框架和工具.本文使用定理证明器Coq,基于MK对实数公理系统进行了深入探索.在优化了MK形式化代码的基础上,形式化构建了完整的实数公理系统,并通过形式化Landau《分析基础》中的实数模型,证明其相对于MK相容,此外,还形式化证明了实数公理系统所有模型在同构意义下是唯一的,验证了实数公理系统的范畴性.本文全部定理无例外地给出Coq的机器证明代码,所有形式化过程已被Coq验证,并在计算机上运行通过,充分体现了基于Coq的数学定理机器证明具有可读性、交互性和智能性的特点,其证明过程规范、严谨、可靠.该系统可方便地应用于拓扑学和代数学理论的形式化构建.谨以此文庆祝我国著名控制系统专家秦化淑研究员九十华诞!

关键词： Morse-Kelley公理化集合论实数公理系统相容性范畴性 Coq 形式化机器证明人工智能

我国农民工群体分布的基本特征、就业趋势与应对策略

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职业技术教育 2024年第15期45卷 74-79页

作者：郭达邢少乐天津职业技术师范大学世界技能大赛中国研究中心天津300222 天津市高校人文社科重点研究基地职业教育发展研究中心天津300222 天津职业技术师范大学职业教育学院

2009-2019年间,在农民工总体规模持续增加但增量和增速逐年下降的关键时期,我国职业教育与培训应基于农民工群体女性比重逐年增加、老龄化态势初显,教育水平以初中为主且提升速度缓慢,接受过职业技能培训的农民工比重和培训意愿双低的... 详细信息

2009-2019年间,在农民工总体规模持续增加但增量和增速逐年下降的关键时期,我国职业教育与培训应基于农民工群体女性比重逐年增加、老龄化态势初显,教育水平以初中为主且提升速度缓慢,接受过职业技能培训的农民工比重和培训意愿双低的基本特征,明晰农民工群体的实际情况,顺应农民工群体的主要变化趋势,实施充分满足农民工发展需求的高质量职业教育与培训,推动东、西部职业教育协同开展农民工职业教育与培训,依托农村职业教育大力培养新型职业农民,通过创业培训重点培养和提升农民工的创业激情和社会资本。

关键词：农民工职业教育与培训就业趋势应对策略