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1.
扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.  相似文献   

2.
论述了CAD技术中参数化设计的三种建模方法,重点介绍了基于特征的参数化建模原理。在此基础上,分析机械设计中的机构结构,归纳出其零件的几何特征构成。设计了机构CAD图形库,并提出了该图形库生成步骤和人机交互界面。  相似文献   

3.
高等教育国际化与中国高等教育施化力培育   总被引:5,自引:2,他引:5  
本文从化层、化型、化向与化力等方面考察高等教育国际化的应然本质属性 ,描述与分析中国高等教育在国际化潮流中表现出的发展态势 ,针对种种态势提出中国高等教育核心施化力培育战略 ,以使中国高等教育乃至世界高等教育真正地走向国际化  相似文献   

4.
Metal Science and Heat Treatment - The effect of the error of measurement of the form of current harmonics on the accuracy of determination of weber-ampere characteristics of electrical devices is...  相似文献   

5.
C. Colinet 《Intermetallics》2003,11(11-12):1095
A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.  相似文献   

6.
刘兴  赵霞 《表面技术》2008,37(1):37-39
采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.  相似文献   

7.
The technology of ultrasonic welding of components made of Capron tapes producing welded joints with high strength parameters has been developed. The numerical values of the main parameters of the conditions of ultrasonic welding of the Capron tapes are determined. It is shown that the increase in the amplitude and welding pressure shortens the welding time. The experimental results show that the Capron tapes are characterized by geometrical homogeneity in both the transverse and longitudinal direction so that the welded joints can be produced both along and across the tape.  相似文献   

8.
Energetics of low-voltage pulsed electroplasmolysis of vegetable raw materials was theoretically and experimentally substantiated for various ways of connection of the working chamber to the power source. The main electrical and technical requirements for designing and realization of the process of electroplasmolysis of cell tissues in various areas of application ensuring electrical safety during work, optimal modes of working, and efficiency are outlined.  相似文献   

9.
运用Pro/E 4.0构建齿轮模型得出齿轮横截面积,把凹模齿形部分看成当量圆,通过齿轮横截面积得到当量直径,从而利用Lame公式理论计算与经验数据的有效结合,对齿轮温锻成形的组合凹模进行优化设计和强度校核。  相似文献   

10.
This paper describes the general features of the functional methods of electrohydropulse, pulse electrocurrent, and magnetic pulse treatment processes of the melt in order to positively vary its crystallizaton ability.  相似文献   

11.
A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.  相似文献   

12.
钢材打捆机控制系统智能化技术的研究   总被引:1,自引:0,他引:1  
钢材打捆机是一种用于轧钢精整工艺的新型自动化设备,其控制系统基于SiemensS7 PLC和TP7触摸屏。系统的智能化技术主要包括:液压高低压自动控制、在线监视、离线故障检测、多台设备协同工作、可视化人机交互技术。本文描述了这些技术的原理与实现方法。  相似文献   

13.
The article discusses the superplasticity properties and structure parameters of cold-worked alloys of a quasi-binary section of the Al-Mg-Si system with a volume fraction of eutectic particles of 0.08–0.18. Mathematical models of yield stress and effective elongation as a function of the structure and engineering parameters have been developed for alloys of this system. An analysis of the developed models shows that, in the temperature range of 520–560°C, superplastic deformation is controlled by the rate of diffusion of aluminum atoms in the grain bulk.  相似文献   

14.
铸件充型数值模拟的研究进展   总被引:3,自引:0,他引:3  
铸造过程计算机数值模拟技术是当今材料科学的重要前沿领域。本文从铸件充型数值模拟的发展过程、软件的开发状况、计算方法及验证方法等四个方面介绍了国内外铸件充型过程计算机数值模拟的概况。  相似文献   

15.
Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.  相似文献   

16.
Metal Science and Heat Treatment - The effect of parameters of hot rolling and controlled cooling on formation of the martensite-austenite component of bainitic and ferritic-bainitic structures in...  相似文献   

17.
The article discusses the process of heterogeneous corrosion using a 3D model of metal consisting of two uniformly intermixed phases destroyed at different rates. The model describes the decrease in the rate of corrosion and the increase in roughness, as well as the formed microrelief of corroded metal as a function of the exposure time. The theoretical equations are verified by computer experiments.  相似文献   

18.
Protection of Metals and Physical Chemistry of Surfaces - A thermodynamic estimation of the Rebinder effect is analytically constructed upon adsorption of sulfonol from an aqueous solution on a...  相似文献   

19.
Conclusions Damping in high-chromium ferritic steels is formed primarily as the result of magnetoelastic dispersion of energy, the level of which is determined by the character of interaction of the magnetic domain boundaries moving in the field of applied cyclic stresses with some subsystems of stoppers, defects of the crystalline structure. The maximum in damping capacity of Kh16, Kh16M4, and Kh25 steels is observed after annealing at 900–1000°C and is the result of superposition of individual oppositely acting on the magnetic constituent of damping contributions during evolution of structural defects under different temperature-time actions. An analysis of the contribution of different crystalline lattice defects makes it possible to predict the path of formation of the controlled level of vibration absorbing properties of high-chromium steels. The high-damping condition is characterized by a low level of internal stresses, moderate values of coercive force, and non-linearity of the elastic properties under the action of external stresses. The damping capacity after annealing in the temperature area of stratification of high-chromium ferrite and appearance of 475°-brittleness is determined by the action of two primary tendencies, the reduction of internal stresses as the result of ecomposition of the supersaturated solid solution of interstitial impurities and the subsequent increase in them as the result of stratification of high-chromium ferrite and formation of zones enriched with chromium.Moscow Institute of the Physics of Metals. Kharkov State University. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 29–34, September, 1993.  相似文献   

20.
吴水康  王长周 《钢管》2006,35(4):20-23
宝山钢铁股份有限公司钢管分公司的穿孔机下辊主减速机在大定修前,减速机轴和下辊大电机的振动情况严重,诊断部门对该减速机进行了测振分析,结合对电机振动、减速机振动的频谱分析和对轴承的故障频率成分分析,找出了主减速机振动的原因是轴承损伤。该分析结果与解体检查的结果相一致。  相似文献   

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