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A Comparative Study of Various Flow Instability Criteria in Processing Map of Superalloy GH4742

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Journal of Materials Science & Technology 2014年第3期30卷 217-222页

作者： Ge Zhou Hua Ding Furong Cao beijiang Zhang College of Materials and Metallurgy Northeastern University High Temperature Materials Division Central Iron and Steel Research Institute

Hot compression tests were conducted on a Gleeble-1500D thermal simulating tester. Based on the deformation behavior and microstructural evolution of superalloy GH4742, different types of instability criteria of Prasad, Gegel, Malas, Murty and Semiatin were compared, and the physical significance of parameters was analyzed. Meanwhile, the processing maps with different instability criteria were obtained. It was shown that instability did not occur when average power dissipation rate was larger than 50% in the temperature range of 1020- 1130℃, corresponding to the strain rate range of 5 × 10-4-3.2 × 10-3 s-1. The domain is appropriate for the processing deformation of superalloy GH4742.

关键词： GH4742 superalloy Hot compression tests Flow instability criterion Processing map

A New View on Processing Gain of DSSS Systems under CW Interference

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China Communications 2007年第2期4卷 54-57页

作者： Li Zhiqiang Zhang beijiang Nanjing Inst Commun Engn Nanjing 210007 Peoples R China

Differing from the general analysis,the process of continuous wave(CW) interference being despreaded in a direct sequence spread spectrum(DSSS) system is reanalyzed. It is proved that the result sequence of continuous wave interference being despreaded varies according to sinusoid in *** frequency and amplitude are *** processing gain is discussed under 3 cases in comparison with traditional *** show that the processing gain varies according to the frequency offset of CW to DSSS signal carrier.

关键词： continuous wave interference direct sequence spread spectrum processing gain

Development of Constitutive Equation and Processing Maps for IN706 Alloy

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 198-204页

作者： Shuo Huang Lei Wang Xintong Lian beijiang Zhang Guangpu Zhao Key lab for Anisotropy and Texture of Materials Northeastern University Department of High-temperature Materials Central Iron and Steel Research Institute

The hot deformation behavior of IN706 has been investigated by means of hot compression tests in the temperature range of 900-1150℃ and strain rate range of 0.001-1 s^-1. The constitutive equation was developed on the basis of experimental data. Power dissipation efficiency （η） and instability parameter （4） maps were evaluated using the principles of the dynamic material model. Furthermore, the EBSD microstructure analysis was performed for validation, revealing that η was closely associated with the mechanism of dynamic recrystallization （DRX）. Microstructure transition map was composed of contour plots of η, 4, and DRX. The DRX domain zones and instable zones were identified in the processing map and were classified based on η. In a view of microstructure refinement and workability improvement, the optimum processing should be selected in the temperature range of 970-1025 ~C and the strain rate range of 0.08-0.01 s^-1.

关键词： IN706 alloy Constitutive equation Power dissipation efficiency Flow instability Processing map

Nucleation mechanism of a nickel-base superalloy during dynamic recrystallization

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Acta Metallurgica Sinica(English Letters) 2011年第4期24卷 295-300页

作者： Shuai WANG Lei WANG Yang LIU GuohuaXU beijiang ZHANG Guangpu ZHAO Key Laboratory for Anisotropy and Texture of Materials Northeastern University Shenyang 110819China High Temperature Materials Research Institute Central Iron and Steel Research Institute Beijing100081 China

Hot compression test was carried out at 1000 ~C to investigate the dynamic recrys- tallization nucleation mechanism of a nickel-base superalloy. It was found that the bulging of original grain boundaries was inhibited by carbides and deformation twins at the boundaries. Recrystallized nuclei evolved from the subgrains of dislocation re- configuration along original grain boundaries, and the growth of the potential nuclei was carried out by the coalescence of subgrains. The necklace structure of recrys- tallized grains along original grain boundaries was attributed to the strain gradient from grain boundary to grain interior.

关键词： Dynamic recrystallization Electron backscattering diffraction(EBSD) Transmission electron microscopy (TEM) Superalloy

EIGHTEEN NEW SPECIES OF PSOCIDS FROM SHAANXI, CHINA(Psocpptera: Stenopsocidae, Psocidae)

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昆虫分类学报 1989年第Z1期 55-59页

作者： Li Fasheng(beijiang Agricultural University)

The present papers deals with psocids collected from Shaanxi Province. A totalof 18 species belonging to 9 genera under 2 families are new to science. The typeare deposited in the Collections of the Beijing Agricultur... 详细信息

关键词： length body Psocidae Psocpptera CHINA EIGHTEEN NEW SPECIES OF PSOCIDS FROM SHAANXI

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比较与借鉴:重释中西民族国家构建理论

云南民族大学学报（哲学社会科学版） 2023年第6期40卷 64-71页

作者：安北江中国社会科学院中国边疆研究所北京100101

西方民族理论体系的形成早于且成熟于中国,中国在民族国家理论构建中,借鉴并吸收了西方相关民族理论。西方民族理论主要有两大体系:一种是崇尚个人意志的自由主义派提倡的政治民主主义,追求“民族”与“国家”合一的最高政治目标,即国... 详细信息

西方民族理论体系的形成早于且成熟于中国,中国在民族国家理论构建中,借鉴并吸收了西方相关民族理论。西方民族理论主要有两大体系:一种是崇尚个人意志的自由主义派提倡的政治民主主义,追求“民族”与“国家”合一的最高政治目标,即国家共同体民族,实现单一民族国家形态,自由成为共识;另一种是以文化血缘为纽带,以族群集体为核心的文化民族主义,即民族共同体民族,实现多民族国家形态,文化属性成为共识。因中西方社会演进历程以及国家构建路径不同,民族理论在不同社会发展阶段所给出的解释也不尽相同。盲目尊崇极端民族主义,为多民族国家的国家建构与国家认同带来阻力,甚至造成民族分裂,引起政治动荡。正确认识民族与国家之间的关系,能够为进一步处理民族认同与国家认同之间的矛盾提供理论依据;对比分析中西方民族理论逻辑,能够阐释中国民族国家建构的特殊性与内在合理性。

关键词：中华民族共同体意识民族民族主义民族国家

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古代中国“天下秩序”理念的传承与变革

思想战线 2023年第2期49卷 123-134页

作者：安北江清华大学马克思主义学院北京100084 中央社会主义学院北京100081

古代中国的“天下秩序”与“国家秩序”建构理论,有着自身的特殊性与传承性,且贯穿于中国多民族国家的形成过程。宗法式与地缘式的“天下秩序”理念,是古人诠释世界和维系国家政治安稳的核心思想。二者相结合,进一步完善了王朝国家政治... 详细信息

古代中国的“天下秩序”与“国家秩序”建构理论,有着自身的特殊性与传承性,且贯穿于中国多民族国家的形成过程。宗法式与地缘式的“天下秩序”理念,是古人诠释世界和维系国家政治安稳的核心思想。二者相结合,进一步完善了王朝国家政治制度体系。中华文明核心体的形成和族群意识的凸显,是“天下秩序”得以传承与变革的基础。“国家秩序”和“国家政治体系”的建立,是古人想象“天下秩序”崩塌与重构的结果。在“国家秩序”建构中,“一统观”与“正统观”成为主体民族政权角逐天下后的政治意识。中华文明的主体性与“天下秩序”理念,形成历史上的“中国精神世界”,最终成为多民族国家统一的向心力。为此,历史上的主体民族政权,以“中国”为核心的天下一统理想才得以实现。阐释古代中国“天下秩序”理念的传承与变革,对进一步理解中国统一多民族国家的形成有着重要意义,同时也间接回应了用西方民族国家理论来倒叙解构历史中国的舛误。

关键词：天下秩序国家秩序中华文明体民族国家

Effect of Low Frequency Electromagnetic Field on Macrosegregation of Horizontal Direct Chill Casting Aluminum Alloys

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Journal of Materials Science & Technology 2005年第1期21卷 75-78页

作者： Zhihao ZHAO, Jianzhong GUI, Jie DONG and beijiang ZHANGThe Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, P.O. Box 314, Northeastern University, Shenyang 110004, ChinaPh.D. candidate, Lab. of Mat. Electromagnetic Proc. Northeastern Univ. Shenyang 110004 P.O. Box 314 China

The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingot but the ingot may suffer from macrosegregation sometimes. In order to control the defect, a low frequency electromagnetic field has been applied in HDC casting process and the relevant influence has been studied. The results show that application of low frequency electromagnetic field can reduce macrosegregation in HDC casting process; and two main parameters of electromagnetic field density and frequency, have great influences on the solution distribution along the diameter of ingot. Moreover, the mechanisms of reduction of macrosegregation by electromagnetic field have been discussed.

关键词： Low frequency electromagnetic field Horizontal direct chill casting Macrosegregation Aluminum alloy

Effects of low-frequency magnetic field on grain boundary segregation in horizontal direct chill casting of 2024 aluminum alloy

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China Foundry 2005年第1期2卷 44-47页

作者： Zhihao ZHAO Jianzhong CUI Jie Dong Haitao Zhang beijiang ZHANG The Key Laboratory of Electromagnetic Processing of Materials Ministry of Education Northeastern University Shenyang 110004 Liaoning P. R. China

Effects of low frequency electromagnetic field on grain boundary segregation in horizontal direct chill (HDC) casting process was investigated experimentally. The grain boundary segregation and microstructures of the ingots, which manufactured by conventional HDC casting and low frequency electromagnetic HDC casting were compared. Results show that low frequency electromagnetic field significantly refines the microstructures and reduces grain boundary segregation. Decreasing electromagnetic frequency or increasing electromagnetic intensity has great effects in reducing grain boundary segregation. Meanwhile, the governing mechanisms were discussed.

关键词： low frequency electromagnetic field grain boundary segregation horizontal direct chill casting