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The Planar Ramsey Numbers PR (K<sub>4</sub>-e, K<sub>l</sub>)

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American Journal of Computational Mathematics 2013年第3期3卷 52-55页

作者： Yongqi Sun Yali Wu Rui Zhang yuansheng yang Department of Computer Science Dalian University of Technology Dalian China School of Computer and Information Technology Beijing jiaotong University Beijing China

The planar Ramsey number PR (H1, H2) is the smallest integer n such that any planar graph on n vertices contains a copy of H1 or its complement contains a copy of H2. It is known that the Ramsey number R(K4 -e, K6) = 21, and the planar Ramsey numbers PR(K4 - e, Kl) for l ≤ 5 are known. In this paper, we give the lower bounds on PR (K4 ? e, Kl) and determine the exact value of PR (K4 - e, K6).

关键词： Planar Graph Ramsey Number Forbidden Subgraph

采用多丝正比室读出的屏栅电离室能量分辨研究

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原子能科学技术 2024年第1期58卷 225-230页

作者：尹小豪魏向伦黄鑫杰邹海川邱天力何周波杨远胜李志杰李蒙马朋杨贺润鲁辰桂胡荣江段利敏中国科学院近代物理研究所甘肃兰州730000 中国科学院大学核科学与技术学院北京100049 兰州大学核科学与技术学院甘肃兰州730000

搭建了一个基于多丝正比室读出的屏栅电离室探测器,使其保留屏栅电离室屏蔽特性的同时具备雪崩放大功能,通过在探测器内部对原初电离信号进行预放大,以提高信噪比,改善探测器的能量分辨率。利用241Am源详细测试了探测器在不同气压、沉... 详细信息

搭建了一个基于多丝正比室读出的屏栅电离室探测器,使其保留屏栅电离室屏蔽特性的同时具备雪崩放大功能,通过在探测器内部对原初电离信号进行预放大,以提高信噪比,改善探测器的能量分辨率。利用241Am源详细测试了探测器在不同气压、沉积能量、阳极丝径时能量分辨率及增益随阳极电压的变化关系。探测器最佳能量分辨对应的工作电压与入射粒子在漂移区中沉积的能量有关,能量沉积越小,对应的最佳工作电压越高,探测器的增益越大。对于5.486 MeV的241Am α粒子源的能量分辨率可达1.45%。

关键词：雪崩放大信噪比能量分辨率空间电荷效应

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Effect of Technological Parameters on Preparation of Mg-based Foam Materials

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Effect of Technological Parameters on Preparation of Mg-base...

Influences of Al, Ce on the Microstructure and Mechanical Properties of As-cast Mg-6Zn Alloy

中国材料大会2012

作者： Hongjie Luo Li Zhang Zhengguo Xu yuansheng yang School of Materials and Metallurgy Northeastern University Institute of Metal Research Chinese Academy of Sciences

ISBN: (纸本)9783037856093

As a novel material,Mg-based foam material not only has fantastic physical characteristics,such as low density,high specific surface area,high specific strength and stiffness,and good biocompatibility,but also has special functional properties,for example,electromagnetic wave shielding,vibration reduction,sound absorption,and so *** can be widely applied to aeronautical and aerospace,military,shipbuilding,transportation,automotive and medical ***-based foam material was prepared by direct foaming in magnesium alloy liquid in this study,and the effect of technological parameters on the products,such as addition amount of and granularity of SiC particles and MgCO3 particles,stirring temperature,stirring time,stirring velocity,foaming temperature and foaming time,was *** aim of this research was to develop a new technology which could fabricate large scale Mg-based foam material in air *** results showed that variations of technological parameters may affect preparation of the foam materials in some extent and resulted in the changes of the products in apparent density,porosity and structural *** light weight Mg-based foam with homogeneous pores could be obtained by suitable combination of the technological parameters.

关键词： Magnesium alloy Silicon carbide Magnesium carbonate Foaming in melt Mg-based foam materials.

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Influences of Al, Ce on the Microstructure and Mechanical Pr...

On Klein tunneling of low-frequency elastic waves in hexagonal topological plates

中国材料大会2012

作者： Ruidong Liu Xuguang Dong Fujun Wei yuansheng yang Institute of Metal Research Chinese Academy of Sciences

ISBN: (纸本)9783037856086

The effects of minor Al and Ce on the microstructures, room-temperature and high-temperature mechanical properties of as-cast Mg-6Zn magnesium alloys were investigated. With the Al addition into Mg-6Zn alloy, the coarse eutectic Mg51Zn20 phases were refined and distributed discontinuously. After adding 0.5wt.% Ce into Mg-6Zn-1Al alloy, a new needle-like Al2CeZn2 phase was observed. Meanwhile, the volume fraction of Mg51Zn20 phase decreased and the semi-continuous Mg51Zn20 phase became discontinuous globular morphology. It has been observed that the addition of Ce element coarsens the grains, and 1wt.% Al addition enhanced the yield strength and ultimate strength from 86.35MPa, 229MPa to 90.7MPa, 238MPa, respectively. Moreover, the Ce addition can significantly increase the high-temperature mechanical properties of cast Mg-6Zn-1Al alloy.

关键词： Magnesium alloy Mg-6Zn alloy Ce High-temperature mechanical properties

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1139-1154页

作者： Yuxin YAO yuansheng MA Fang HONG Kai ZHANG Tingting WANG Haijun PENG Zichen DENG School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian116024Liaoning ProvinceChina

Incident particles in the Klein tunnel phenomenon in quantum mechanics can pass a very high potential *** the concept of tunneling into the analysis of phononic crystals can broaden the application *** this study,the structure of the unit cell is designed,and the low frequency(<1 k Hz)valley locked waveguide is realized through the creation of a phononic crystal plate with a topological phase transition *** defect immunity of the topological waveguide is verified,that is,the wave can propagate along the original path in the cases of impurities and ***,the tunneling phenomenon is introduced into the topological valley-locked waveguide to analyze the wave propagation,and its potential applications(such as signal separators and logic gates)are further explored by designing phononic crystal *** research has broad application prospects in information processing and vibration control,and potential applications in other directions are also worth exploring.

关键词： topological metamaterial elastic wave Klein tunneling valley-locked waveguide

民族古文献阅读与重要名词术语文化解析——以彝族古文献为例

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图书馆论坛 2019年第7期39卷 114-122页

作者：朱崇先杨元晟中央民族大学

文章主要阐述民族古文献阅读的意义、背景和阅读人群的分类以及文献读物的种类;以彝族古文献为例,运用词源学、语音学、历史语言学等相关知识,对民族古文献中出现的名词术语进行词义辨析及文化解读,进一步阐释民族古文献名词术语的深刻... 详细信息

文章主要阐述民族古文献阅读的意义、背景和阅读人群的分类以及文献读物的种类;以彝族古文献为例,运用词源学、语音学、历史语言学等相关知识,对民族古文献中出现的名词术语进行词义辨析及文化解读,进一步阐释民族古文献名词术语的深刻内涵和文化解读的重要意义。

关键词：民族古文献阅读词义辨析文化解读

Structure and Stability of TiC/γ Interface inFe-Cr-Ni Base Composite

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Journal of Materials Science & Technology 1999年第2期15卷 151-154页

作者： Xidong HUI yuansheng yang and Xnqiang WU (Institute of Metal Research, Chinese Academia of Science, Shenyang 110015, China)Zhifu WANG(Shandong University of Technology, Jinan 250061, China)Xichen CHEN(Institute of Physics, Chinese Academia of Science, Be Institute of Metal Research Chinese Academia of Science Shenyang 110015 China Shandong University of Technology Jinan 250061 China Institute of Physics Chinese Academia of Science Beijing 100080 China

The morphology. orientation relationship and stability of TiC/γ interface in Fe-Cr-Ni base composite synthesized with a liquid state in-situ process have been studied. The TiC/γ interface in as-cast sample is of coherent feature. Its orientation relationship is (020)γ／／(220)TiC, [001]γ||[001]TiC. During the aging at 1473 K, the TiC/γ interface may dissolve in matrix and lamellar M23C6 compound may precipitate from γ-matrix.

关键词： Structure and Stability of TiC Base Cr Interface inFe-Cr-Ni Base Composite Ni

Application of Low Voltage Pulsed Magnetic Field in Solidification of Metals

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Application of Low Voltage Pulsed Magnetic Field in Solidifi...

“第十届中国钢铁年会”暨“第六届宝钢学术年会”

作者： yang yuansheng Li Yingju Luo Tianjiao Ji Huanming Feng Xiaohui Institute of Metal Research Chinese Academy of Sciences

The grain refinement of static castings and DC-casting ingots was achieved with a low-voltage pulsed magnetic field setup. Through the study of the interaction between melt and the low-voltage pulsed magnetic field（LVPMF）, a 3-D model was established for simulation of the electromagnetic force, melt flow, heat and mass transfers. The effects of the LVPMF on the solidified structure of silicon steel and Ni-based superalloy as well as magnesium alloy were investigated, and the optimized processing parameters were obtained for grain refinement of the alloys. Based on the dynamic theories for crystal growth under melt flow and the LMK marginally stable theory, the mechanics of the interface morphology changing from typical dendrite to globular morphologies with the LVPMF was explained. Combined with the simulation results on electromagnetic vibration and convection caused by the LVPMF and experimental results, the grain refinement mechanism was discussed in terms of nucleation and growth theories.

关键词： pulsed magnetic field casting grain refinement electromagnetic vibration melt convection

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小单元多丝漂移室探测器系统研制

原子能科学技术 2024年第1期58卷 218-224页

作者：黄鑫杰尹小豪何周波马朋胡荣江邹海川邱天力何志轩秦智秦雨浩魏向伦杨贺润鲁辰桂李蒙杨远胜李志杰段利敏中国科学院近代物理研究所甘肃兰州730000 中国科学院大学核科学与技术学院北京100049 兰州大学核科学与技术学院甘肃兰州730000 清华大学物理系北京100084

为精确测量CSR外靶终端靶前入射粒子的径迹,研制了多套小单元多丝漂移室探测器,该探测器灵敏面积为80 mm×80 mm,每套探测器包括x、x′、y、y′4个探测电极面,每个电极面引出16个阳极丝信号。前端电子学采用基于SFE16芯片的放大器,数据... 详细信息

为精确测量CSR外靶终端靶前入射粒子的径迹,研制了多套小单元多丝漂移室探测器,该探测器灵敏面积为80 mm×80 mm,每套探测器包括x、x′、y、y′4个探测电极面,每个电极面引出16个阳极丝信号。前端电子学采用基于SFE16芯片的放大器,数据读出系统采用基于HPTDC芯片的数据采集卡。采用两套小单元多丝漂移室对400 MeV/u的^(16)O束流位置进行了测试,探测器的工作气体为Ar(80%)+CO_(2)(20%),阳极丝电压为+900 V,场丝与阴极丝均接地,拟合得到的单层电极的位置分辨(拟合残差)为105.9μm,探测效率为99.3%,该指标可以满足现阶段CSR外靶终端大部分核物理实验对反应靶点的定位要求。

关键词：小单元多丝漂移室位置分辨探测效率

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