检索结果-南通市图书馆

Dynamical modeling and non-planar coupled behavior of inclined CFRP cables under simultaneous internal and external resonances

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第5期40卷 649-678页

作者： Houjun KANG Tieding GUO Weidong ZHU junyi su Bingyu ZHAO Hunan Provincial Key Lab on Damage Diagnosis for Engineering Structures Hunan University Department of Mechanical Engineering University of Maryland College of Civil Engineering Hunan University

A dynamic model for an inclined carbon ?ber reinforced polymer(CFRP)cable is established, and the linear and nonlinear dynamic behaviors are investigated in detail. The partial differential equations for both the in-plane and out-of-plane dynamics of the inclined CFRP cable are obtained by Hamilton's principle. The linear eigenvalues are explored theoretically. Then, the ordinary differential equations for analyzing the dynamic behaviors are obtained by the Galerkin integral and dimensionless *** steady-state solutions of the nonlinear equations are obtained by the multiple scale method(MSM) and the Newton-Raphson method. The frequency-and force-response curves are used to investigate the dynamic behaviors of the inclined CFRP cable under simultaneous internal(between the lowest in-plane and out-of-plane modes) and external resonances, i.e., the primary resonances induced by the excitations of the in-plane mode,the out-of-plane mode, and both the in-plane mode and the out-of-plane mode, respectively. The effects of the key parameters, e.g., Young's modulus, the excitation amplitude,and the frequency on the dynamic behaviors, are discussed in detail. Some interesting phenomena and results are observed and concluded.

关键词： inclined carbon fiber reinforced polymer(CFRP)cable bifurcation nonlinear dynamics internal resonance external resonance

A Mathematical Model for Predicting Shrinkage Defect of Ductile Iron Castings

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 24-29页

作者： ZhiqiangHan junyi su Kaike Cai Metallurgy School, University of Science and Technology Beijing, Beijing 100083, China Xi’an Jiaotong University, Xi’an 710049, China Metallurgy School University of Science and Technology Beijing Beijing 100083 China Xi'an Jiaotong University Xi'an 710049 China

The shrinkage defect of a ductile iron casting is attributed to the volume variations occurring in solidification, which consist of liquid contraction, solidification shrinkage, graphitization expansion, and mold cavity enlargement. Based on this understanding, a mathematical model for predicting the shrinkage defect of the casting is developed, in which the volume variations of the casting in soli- dification are numerically simulated, especially, the mold cavity enlargement is quantitatively calculated. Moreover, the reliability of the model is verified in production and experiment.

关键词： ductile iron casting shrinkage defect mold cavity enlargement mathematical model

Analysis of electromagnetic pressure on thin plate melt

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第23期44卷 2141-2145页

作者： Jun Shen Jianguo Li Hengzhi Fu junyi su Northwestern Polytech Univ State Key Lab Solidificat Proc Xian 710072 Peoples R China Xian Jiao Tong Univ Dept Mech Engn Xian 710049 Peoples R China

An equation used to calculate electromagnetic pressure for confining and shaping a plate-form melt with small or medium thickness is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and current frequency f, melt thickness a and electromagnetic parameter MX ?The main results can be summarized as follows: ( i )

关键词： electromagnetic confinement and shaping electromagnetic pressure magnetic flux density.

Grain refinement effect of La_2(CO_3)_3 on AZ91 magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第Z2期25卷 160-162页

作者： WANG Ling ZHAO Haofeng GUO Shengli su junyi Department of Materials College of Mathematics and Physics Nanjing Information University of Science and Technology Nanjing 210044 China Department of Materials College of Mathematics and Physics Nanjing Information University of Science and Technology Nanjing 210044 China Department of Materials Processing College of Materials Xi''an Jiaotong University Xi''an 740078 China Department of Materials College of Mathematics and Physics Nanjing Information University of Science and Technology Nanjing 210044 China Department of Materials College of Mathematics and Physics Nanjing Information University of Science and Technology Nanjing 210044 China Department of Materials Processing College of Materials Xi''an Jiaotong University Xi''an 740078 China

The La2(CO3)3 addition makes the grain of AZ91 alloy be refined obviously. The average primary dendrite size of the alloy decreases from 150 to 50 μm. The microstructure of typical dendrite turns into the equal-axed grain with the addition of 2.5 wt.% La2(CO3)3 refiner. The mechanical properties tests indicate that the tensile strength and especially elongation of the alloys are improved with the addition of La2(CO3)3 and their maximum enhancing rates based on the La2(CO3)3-free AZ91 alloy are 26% and 5.2 times at 2.5 wt.% La2(CO3)3 refiner respectively.

关键词： AZ91 alloy La2(CO3)3 microstructure mechanical properties

SNOWY COTYLEDON 2 Promotes Chloroplast Development and Has a Role in Leaf Variegation in Both Lotus japonicus and Arabidopsis thaliana

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2017年第5期10卷 721-734页

作者： Nicola Zagari Omar Sandoval-lbanez Niels Sandal junyi su Manuel Rodriguez-Concepcion Jens Stougaard Mathias Pribil Dario Leister Pablo Pulido Plant Molecular Biology Department of Biology I Ludwig-Maximilians-Universitat Munchen 82152 Planegg-Martinsried Germany Copenhagen Plant Science Center University of Copenhagen 1871 Frederiksberg C Denmark Research and Innovation Center Fondazione Edmund Mach via E. Mach 1 38010 San Michele all'Adige Italy Centre for Carbohydrate Recognition and Signalling Department of Molecular Biology and Genetics Aarhus University Gustav Wieds Vej 10 8000 Aarhus C Denmark Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB Campus UAB Bellaterra 08193 Barcelona Spain

Plants contain various factors that transiently interact with subunits or intermediates of the thylakoid multiprotein complexes, promoting their stable association and integration. Hence, assembly factors are essential for chloroplast development and the transition from heterotrophic to phototrophic growth. Snowy cotyledon 2 （SCO2） is a DNAJ-like protein involved in thylakoid membrane biogenesis and interacts with the light-harvesting chlorophyll-binding protein LHCBI. In Arabidopsis thaliana, SCO2 function was previ- ously reported to be restricted to cotyledons. Here we show that disruption of SC02 in Lotus japonicus results not only in paler cotyledons but also in variegated true leaves. Furthermore, smaller and pale- green true leaves can also be observed in A. thaliana sco2 （atsco2） mutants under short-day conditions. In both species, SCO2 is required for proper accumulation of PSlI-LHCll complexes. In contrast to other variegated mutants, inhibition of chloroplastic translation strongly affects L. japonicus sco2 mutant devel- opment and fails to suppress their variegated phenotype. Moreover, inactivation of the suppressor of variegation AtClpR1 in the atsco2 background results in an additive double-mutant phenotype with variegated true leaves. Taken together, our results indicate that SCO2 plays a distinct role in PSll assembly or repair and constitutes a novel factor involved in leaf variegation.

关键词： SCO2 DNAJ-like photosynthesis assembly factor variegation chloroplast development

NUMERICAL SIMULATION ON SOLIDIFICATION OF HORIZONTALLY CONTINUOUSLY CAST IRON BARS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1990年第12期3卷 384-390页

作者： ZHU Xianhua DONG Zengzhang su junyi Xi’an Jiaotong University,Xi’an,China

The solidification process of a horizontally continuously cast gray iron bar of 4.6cm in diame- ter was *** function describing the distribution of heat flux at the internal surface of graphite sleeve,which was equal to that on the surface of the iron bar,was inversely derived using numerical calculation from the temperature distribution in the sleeve measured in real *** using the distribution of heat flux as a boundary condition on the surface of the iron bar,the numerical simulation on solidification of the iron bar taking longitudinal heat conduction into account was *** profile of solidification front obtained from the numer- ical simulation was approximately coincident with that in real *** addition,the quantitative relationships of the thickness of solidified shell at the exit of the mold to the main technological parameters,including the temperature of liquid iron at the entrance of the mold, the moving speed of the bar and the intensity of water cooling,were obtained from the numeri- cal simulation.

关键词： continuous casting cast iron solidification numerical simulation

Electromagnetic Confinement and Shaping for Plate-Form Part

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2000年第1期16卷 27-32页

作者： Jun SHEN, Jianguo LI and Hengzhi FU (State Key Laboratory of Solidification Processing, Northwestern Polytechnic University, Xi’an 710072, China) junyi su (Xi’an Jiaotong University,Xi’an 710049, China) State Key Laboratory of Solidification Processing Northwestern Polytechnic University Xi'an 710072 China Xi'an Jiaotong University Xi'an 710049 China

than 2.2, the electromagnetic pressure acting on melt can be simply expressed as Pm =B^2/wμ, and the melt shape would be known only by measuring the distribution of magnetic flux density. As a is small and makes the ratio a/8 less than 2.2, the melt shape and electromagnetic pressure for confining and shaping are determined not only by magnetic flux density B but also by melt thickness a, electromagnetic parameter μγ and current frequency f. In this paper, an equation used to calculate electromagnetic pressure acting on 'thin plate-form melt' is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and melt thickness a, electromagnetic parameter μγ and current frequency f.

关键词： Electromagnetic Confinement and Shaping for Plate-Form Part Form

在线全文

学校读者我要写书评

暂无评论

一种提高铸件凝固过程数值计算效率的方法

西安交通大学学报 2000年第1期34卷 50-54页

作者：刘伟涛苏俊义西安交通大学西安710049

基于显式差分法，提出了一种占用内存少并能提高砂型铸件凝固过程数值计算效率的方法．采用一个数据块存储铸件／砂型系统的温度场以节省内存，对砂型和铸件区域采用不同的时间步长分别进行计算以提高计算速度，并选择适当的方法处理２... 详细信息

基于显式差分法，提出了一种占用内存少并能提高砂型铸件凝固过程数值计算效率的方法．采用一个数据块存储铸件／砂型系统的温度场以节省内存，对砂型和铸件区域采用不同的时间步长分别进行计算以提高计算速度，并选择适当的方法处理２个计算域的耦合问题．通过一个实例证明，该算法可使模拟计算速度提高１倍，而计算所得的铸件温度场几乎与传统算法一致．

关键词：凝固过于过程数值模拟交替计算铸造铸件

在线全文

学校读者我要写书评

暂无评论

工业灰铸铁凝固组织形成过程的数值模拟

西安交通大学学报 2000年第3期34卷 83-86页

作者：张云鹏苏俊义西安交通大学西安710049

从接近工业灰铸铁实际凝固过程的角度出发 ,提出了对凝固组织进行数值模拟的一套方法 ,主要包括枝晶奥氏体生长过程体积分数的计算以及晶粒接触因素的处理 .该方法经以样杯中浇铸的试块为对象进行实验验证 ,证明模拟得到的冷却曲线。

关键词：凝固组织数值模拟形成过程灰口铸铁铸件