杨金瑞
,
余尚先
,
顾江楠
高分子材料科学与工程
通过对resol(羟甲基酚化合物和低分子量羟甲基酚树脂)DEPT135图谱的分析讨论,得到一系列计算resol微细结构参数的经验公式.根据DEPT135图谱可判断是否发生缩聚反应,根据经验公式可计算酚单体各个活性点参与反应百分率或酚羟基导入率、不同类型缩聚所占百分率及低分子量羟甲基酚树脂的平均核体数.
关键词:
羟甲基酚化合物
,
羟甲基酚树脂
,
DEPT135
,
结构参数
LIU Guoquan Department of Materials Science and Engineering
,
University of Science and Technology Beijing
,
100083
,
China.
材料科学技术（英文）
Quantitative analysis of populations having a geometric structure,which has developed into a special scientific subject called microstructology or stereology,is of great importance to the characterization and evaluation of microstructures and their evolution in various processes.This paper, besides a brief discussion on those topics such as the recent developments of computer assisted image analysis,mathematical morphology,and fractal analysis,will mainly focus on the scope,fundamen- tals,present status,and perspectives of classical stereology.Several case examples of its application to materials science will also be given.
关键词:
stereology
,
null
,
null
,
null
J. T. Niu
,
H. T. Li
,
X. D. Meng and P. Karjaleinen 1) Analysis and Measurement Center
,
Harbin Institute of Technology
,
Harbin 150001
,
China 2) Department of Mechanocal Engineering
,
The University of Oulu
,
Finland
金属学报(英文版)
With the development of modern science and technology, especially computer science, the numerical simulation method has been widely used in material hot-working. Mary achievements have been made in this field by using the numerical simulation method. The numerical simulation method, especially finite element method fully described in this paper.Applications of the numerical simulation method in material hot-working are also discussed. Finally, the future of the numerical simulation method is outlined.
关键词:
numerical simulation
,
null
,
null
Biomaterials
A natural self-reinforced composite material, bamboo, is studied for the first time as a biomedical material. Its anatomical structure was investigated and its mechanical properties were measured and compared with those of some common bone-bonding or bone-repairing biomaterials. It is found that, among all kinds of biomaterials, bamboo has the closest modulus of elasticity to human long bone. The cytotoxicity of bamboo was tested using the agar overlay method before and after heat or chemical treatments. The results reveal that ethanol, methanol and toluene can remove toxic leachable components from bamboo to some extent through extraction. After grafting a polymer whose molecule includes poly(ethylene glycol), alpha,omega-di(aminopropyl)poly(ethylene glycol) 800 on bamboo, bamboo has the ability to form a calcium phosphate coating after being immersed in calcification solution (simulated body fluid and accelerated calcification solution). The characteristics and the morphology of the mineral formed on bamboo were studied by infrared spectroscopy and scanning electron microscopy. (C) 1997 Elsevier Science Limited. All rights reserved.
关键词:
bamboo;grafts;calcium phosphate;corrosion films
Physics Letters A
Two-dimension spring square network model involving the nearest and second neighbour bonds is studied by numerical simulation with Gauss-Seidel iteration for brittle fracture Mode 1. The material-dependent parameter, G(0)/G, is introduced in this simulation, G and G(0) are the parameters related to the elastic moduli of the nearest and second neighbour, bonds, respectively. Brittle fracture of materials with different G(0)/G are simulated under the same quenched disorder. The fractal dimension of crack fluctuates with G(0)/G. It seems that it is impossible for different materials to have a universal fractal dimension of crack in brittle fracture. However, it is possible to have different so-called universal fractal dimensions. (C) 2003 Elsevier Science B.V All rights reserved.
关键词:
fracture;crack;fractal dimension;scanning-tunneling-microscopy;surfaces;roughness;geometry;metals;model
材料科学技术（英文）
A novel water-soluble core material composed of polyethylene glycol, sodium chloride, mica powder and plasticizer was prepared. The compressive strength, bend strength, hygroscopic coefficient and the material solubility in water were investigated. The results show that the compressive yield strength of the soluble core can reach 1 MPa and the highest compressive strength can reach 4 MPa, the bend strength is as high as 6.65 MPa, the hygroscopic coefficient is lower than 0.22%/month and the solubility of suitable core material is 35.7-55.75 g/(min.m(2)). The wax pattern with undercuts was prepared successfully by using the novel water-soluble core material.
关键词:
Investment cast;Core materials;Mechanical properties;Microstructure
Weiguo Jiang
材料科学技术（英文）
A novel water-soluble core material composed of polyethylene glycol, sodium chloride, mica powder and plasticizer was prepared. The compressive strength, bend strength, hygroscopic coefficient and the material solubility in water were investigated. The results show that the compressive yield strength of the soluble core can reach 1 MPa and the highest compressive strength can reach 4 MPa, the bend strength is as high as 6.65 MPa, the hygroscopic coefficient is lower than 0.22%/month and the solubility of suitable core material is 35.7-55.75 g/(min·m2). The wax pattern with undercuts was prepared successfully by using the novel water-soluble core material.
关键词:
Investment cast
,
Core materials
,
Mechanical property
,
Microstructure
YU Qingbo
,
LU Zhongwu
,
CAI Jiuju
钢铁研究学报(英文版)
From the viewpoint of systems energy conservation, the influences of material flow on its energy consumption in a steel manufacturing process is an important subject. The quantitative analysis of the relationship between material flow and the energy intensity is useful to save energy in steel industry. Based on the concept of standard material flow diagram, all possible situations of ferric material flow in steel manufacturing process are analyzed. The expressions of the influence of material flow deviated from standard material flow diagram on energy consumption are put forward.
关键词:
steel manufacturing process;material flow;energy consumption;calculating method
