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Acta Metallurgica Sinica(English Letters) 2020年第6期33卷 828-838页

作者： Jinyong gao Lijun Yang Lei Cui Peng Lu Jun Yang yanjun gao Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin 300350China Capital Aerospace Machinery Corporation Beijing 100044China

In the present study, the weld formation and mechanical properties of the AA-5A06 friction pull plug welded(FPPW) joints were improved by controlling the axial force history. Several defect-free FPPW joints were made successfully by using the welding parameters of 15–20 k N/s axial loading rate, 20–30 k N axial welding force and 6–7 mm axial feeding displacement. The results indicated that using higher axial loading rate and axial welding force produced more stable heat generation and shorter frictional heating time between the frictional interface. In this case, the plastic flow of the materials around the hole could be further improved since the axial feeding displacement of the plug was increased. The maximum ultimate tensile strength(UTS) and elongation of the FPPW 5A06 joints were 314 MPa and 4.8%, respectively. The thermal mechanically affect zone(TMAZ) had the lowest hardness value throughout the joint and was found as the fracture location to all the tensile samples. The softening of TMAZ was mainly caused by the weakening of the cold work hardening and the coarsening of grains.

关键词： Friction pull plug welding Parameter optimization Microstructures Mechanical properties

Analysis of local microstructure and strengthening mechanisms in adjustable-gap bobbin tool friction stir welds of Al-Mg

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International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1589-1595页

作者： Dong Wu Wenya Li Qiang Chu Yangfan Zou Xichang Liu yanjun gao State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi’an 710072China Capital Aerospace Machinery Company Beijing 100076China

The bobbin tool friction stir welding process was used to join 6 mm thick 5A06 aluminum alloy *** microscope was used to characterize the *** electron backscatter diffraction(EBSD)identified the effect of non-homogeneous microstructure on the tensile *** was observed that the grain size in the top of the stir zone(SZ)is smaller than that in the centre *** lowest ratio of recrystallization and density of the geometrically-necessary dislocations(GNDs)in the SZ was found in the middle near the thermo-mechanically affected zone(TMAZ)being 22%and 1.15×10^(−13) m^(−2),*** texture strength of the heat-affected zone(HAZ)is the largest,followed by that in the SZ,with the lowest being in the *** were additional interfaces developed which contributed to the strengthening mechanism,and their effect on tensile strength was *** tensile tests identified the weakest part in the joint at the interfaces,and the specific reduction value is about 93 MPa.

关键词： friction stir welding bobbin-tool local microstructure strengthening mechanisms adjustable-gap

Fast charge transport motivated by tunable Mo2C/Mo2N high-quality heterointerface for superior pseudocapacitive storage

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Journal of Energy Chemistry 2023年第8期83卷 465-477,I0012页

作者： yanjun gao Shaohua Zhang Lingrui Xu Xiangyang Li Lijie Li Lixia Bao Jiong Peng Xin Li School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China School of Material Science and Engineering Beijing Institute of TechnologyBeijing 100081China Analysis&Testing Center Beijing Institute of TechnologyBeijing 100081China

The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface ***,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics *** analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions *** small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on ***,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is *** work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.

关键词： Energy storage Hybrid supercapacitors Pseudocapacitance Heterojunction High-quality interface

Scattered Rural Settlements and Development of Mountainous Regions in Western Sichuan,China

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Wuhan University Journal of Natural Sciences 2007年第4期12卷 737-742页

作者： gao yanjun CHEN Guojie SHEN Maoying Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduate University of Chinese Academy of Sciences Beijing 100049 China Sichuan Academy of Social Sciences Chengdu 610072 Sichuan China

Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction, farmers＇ income increase and mountain ecological reconstruction in mountainous regions of western Sichuan. The results indicate that economic density is positively related to both rural settlements density （R^2=0.73） and rural population density （R^2=0.77）, and it is the same for relationship between towns density and rural settlements density （R^2=0.88） and between towns density and economic density （R^2=0.71）, and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County, the paper indicates the spatial distribution model and the industrial development model of the rural settlements need to be changed, and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.

关键词： mountainous regions in western Sichuan rural settlement scattered distribution development

河南省新型农业现代化服务组织体系评价及其空间分布规律研究

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中国生态农业学报 2017年第7期25卷 1090-1098页

作者：高延军河南科技大学经济学院洛阳471023 河南科技大学高等教育与区域经济发展研究中心洛阳471023

基于2014年中央提出的农业发展"三个导向"要求,本文构建了由土地流转、资源配置、信息服务、产业管理"四大组织"构成的新型农业现代化服务组织体系评价模型,以河南省18个市为基本单元,对服务组织体系的综合发展水平进行了评价,并探讨了... 详细信息

基于2014年中央提出的农业发展"三个导向"要求,本文构建了由土地流转、资源配置、信息服务、产业管理"四大组织"构成的新型农业现代化服务组织体系评价模型,以河南省18个市为基本单元,对服务组织体系的综合发展水平进行了评价,并探讨了空间分布规律。结果表明:河南省新型农业现代化服务组织体系整体发展水平较低,进入Ⅰ、Ⅱ类地区的只有3个市(郑州、济源、漯河),其余15个市集中在Ⅲ、Ⅳ、Ⅴ、Ⅵ类地区。空间分布有一定规律,豫西整体水平较高,洛阳、济源、焦作、三门峡都在Ⅱ或Ⅲ类地区;其次为豫中,郑州、漯河分别进入Ⅰ、Ⅱ类地区,但许昌、平顶山均在Ⅴ类地区;再次为豫北,鹤壁进入Ⅲ类地区,新乡、安阳、濮阳却停留在Ⅳ、Ⅴ类地区;然后为豫南,南阳、信阳、驻马店都处于Ⅴ类地区;最后为豫东,商丘、周口均为Ⅵ类地区,开封也只进入Ⅳ类地区。研究表明,河南省应构建完善的新型农业现代化服务组织体系,引导农地规模化流转,提高生产经营组织化程度,推进农业发展方式转变,保障农产品质量数量安全,这是加快农业现代化发展的必然选择。

关键词：河南省新型农业现代化发展服务组织体系空间分布规律

A MRI quantitative study of corpus callosum in normal adults

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Journal of Medical Colleges of PLA(China) 2008年第6期23卷 346-351页

作者： Yang Junle Guo Youmin gao yanjun Ma Mingyue Zhang Qiujuan Xu Min Imaging Center Second Affiliated Hospital Xi＇an Jiaotong University Xi ＇an 710004 China Imaging Center Xi＇an Central Hospital Xi ＇an 710004 China

Objective： To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods： Magnetic resonance images of 286 healthy adults, including 127 males and 159 females, and ranging in age from 20 to 81 years, were investigated. They were classified into 5 age groups （ 20-29, 30-39, 40-49, 50-59, and 60-81 years old）. Corresponding to the age group sequence above, the male/female ratio of each group respectively was： 25/26, 26/33, 33/50, 32/36, and 11/14. The following dimensions of corpus callosum were systematically measured on the midsagittal Tl-weighted images： frontal to occipital pole （represented as line segment AB）, total longitudinal dimension of the corpus callosum （CD）, the maximum height （EF）, the widths of the genu （CX）, anterior one third （GH）, central region （EZ）, posterior one third （MN） and splenium （YD）. After that, the obtained data was analyzed statistically. Results：（1） The total longitudinal dimension, maximum height, widths of the genu, central region and splenium were proved to be larger in females. But the widths of the anterior one third and posterior one third were similar in-between. In spite of that, a conspicuous sex-related difference was not found. （2） The total longitudinal dimension and the maximum height of the corpus callosum remained stable in all age subgroups. Yet the widths of the genu, anterior one third, central region, posterior one third and splenium had a tendency of decreasing gradually with aging. Statistical difference was seen in the anterior one third, central region, posterior one third （P〈0.05）. Conclusion： There is no sex-related difference in all dimensions of corpus callosum. But, with aging, a significant difference is found in the widths of the anterior one third, central region and posterior one third.

关键词： Normal adults Corpus callosum Magnetic resonance imaging

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油液特性对柱塞泵流量脉动影响的仿真分析

中国机械工程 2017年第11期28卷 1333-1338页

作者：高彦军谷立臣焦龙飞陕西交通职业技术学院汽车工程学院西安710018 西安建筑科技大学机械电子技术研究所西安710055

为研究油液特性对轴向柱塞泵流量脉动的作用规律,对比分析了油液的压缩性、黏性、含气量和流动状态与柱塞泵流量脉动之间的关系,运用FLUENT流场仿真软件对轴向柱塞泵的运动特性进行模拟。数值仿真结果表明:压缩性对泵源流量脉动的影响最... 详细信息

为研究油液特性对轴向柱塞泵流量脉动的作用规律,对比分析了油液的压缩性、黏性、含气量和流动状态与柱塞泵流量脉动之间的关系,运用FLUENT流场仿真软件对轴向柱塞泵的运动特性进行模拟。数值仿真结果表明:压缩性对泵源流量脉动的影响最大,油液黏性的影响次之,含气量的影响较小,流动状态的影响最小,以上因素的影响程度占油液特性影响的比例分别为86.8%、9.45%、3.59%、0.16%;油液的黏性对泵容积效率的影响最大,压缩性的影响次之,含气量的影响较小,流动状态的影响最小。模型的准确性得到了实验验证,为开展柱塞泵动力学建模以及机电液系统全局耦合性能仿真分析提供了理论依据。

关键词：轴向柱塞泵流量脉动容积效率压缩性油液黏性流场仿真

Formation of a silicon micropore array of a two-dimension electron multiplier by photo electrochemical etching

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Journal of Semiconductors 2009年第2期30卷 13-16页

作者：高延军端木庆铎王国政李野田景全 Changchun University of Science and Technology Jilin University

A semiconductor PEC etching method is applied to fabricate the n-type silicon deep micropore channel array. In this method, it is important to arrange the direction of the micropore array along the crystal orientation of the Si substrate. Otherwise, serious lateral erosion will happen. The etching process is also relative to the light intensity and HF concentration. 5% HF concentration and 10-15 cm distance between the light source and the silicon wafer are demonstrated to be the best in our experiments. The n-type silicon deep micropore channel array with aperture of 3/2m and aspect ratio of 40-60, whose inner walls are smooth, is finally obtained.

关键词： photo-electrochemical etching MCP electron multiplier micropore deep-channel n-type silicon

直接甲酸钠/铁氰化钾微流体燃料电池性能研究

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化学学报 2022年第9期80卷 1256-1263页

作者：刘春梅高燕均陈鹏亮河南科技大学热能工程系洛阳471003

微流体燃料电池(MFC)利用两股流体在微通道内呈平行层流的特性,无需传统燃料电池中的质子交换膜,自动将燃料与氧化剂隔开.本工作构建了阴阳极均为碱性介质且阴极无催化剂即可反应的直接甲酸钠/铁氰化钾MFC,考察了反应物流速、氧化剂浓... 详细信息

微流体燃料电池(MFC)利用两股流体在微通道内呈平行层流的特性,无需传统燃料电池中的质子交换膜,自动将燃料与氧化剂隔开.本工作构建了阴阳极均为碱性介质且阴极无催化剂即可反应的直接甲酸钠/铁氰化钾MFC,考察了反应物流速、氧化剂浓度、燃料浓度对该电池产电性能的影响.实验结果表明,在反应物流速为200μL·min^(−1),铁氰化钾氧化剂浓度为1 mol·L^(−1),甲酸钠燃料浓度为1.5 mol·L^(−1)时,该微流体燃料电池性能达到最优,其最高功率密度为123.93 mW·cm^(−2),极限电流密度为220.93 mA·cm^(−2).为了获得该电池的稳定运行性能,对电池进行了恒电压放电实验.结果表明,该电池在2.25 h内可以持续较稳定地放电.此外,对该电池在开路状态下进行了电化学阻抗谱测试,获得该电池内阻为18.4Ω.

关键词：微流体燃料电池甲酸钠铁氰化钾液态氧化剂碱性介质性能研究

n型掺杂BaSnO_3的电子结构和光学性能的第一性原理研究

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稀有金属材料与工程 2014年第5期43卷 1387-1391页

作者：谭兴毅高雁军陈长乐金克新湖北民族学院湖北恩施445000 西北工业大学凝聚态结构与性质陕西省重点实验室陕西西安710129

基于密度泛函理论,从头计算了La以及Nb掺杂BaSnO3的稳定性、电子结构和光学性质。结果表明La以及Nb掺杂BaSnO3体系结构稳定,均为n型导电材料,在可见光区透过率大于80%,且La以及Nb掺杂BaSnO3明显改善了体系的导电性。计算结果为实验制备n... 详细信息

基于密度泛函理论,从头计算了La以及Nb掺杂BaSnO3的稳定性、电子结构和光学性质。结果表明La以及Nb掺杂BaSnO3体系结构稳定,均为n型导电材料,在可见光区透过率大于80%,且La以及Nb掺杂BaSnO3明显改善了体系的导电性。计算结果为实验制备n型BaSnO3基透明导电材料提供了理论指导。

关键词：透明导电材料电子结构光学性质

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