胫骨生物陶瓷复合材料的微结构增韧机理

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.     

钢材打捆机控制系统智能化技术的研究

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。     

Role of Martensite-Austenite Component of Bainitic Structure in Formation of Properties of Pipe Steel. 1. Effect of Parameters of TMT

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...     

FeCrAIW电弧喷涂层组织的致密化研究

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.     

铸件充型数值模拟的研究进展

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。     

高等教育国际化与中国高等教育施化力培育

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     

Modelling of processes of thermochemical treatment of metals: traditions of Russian scientific school

Abstract

The paper is devoted to 100th anniversary of the outstanding Russian scientist professor Yuriy Mikhailovich Lakhtin – the founder of the world-famous scientific school of surface strengthening of metals and alloys. Lakhtin's scientific school is recognised for its contribution into research of processes of thermochemical treatment of metals and especially of nitriding. Today at the Department of Metal Science and Heat Treatment of MADI his followers continue the traditions of Lakhtin's scientific school. The development of technologies of surface engineering is based on complex modelling of physical processes realised by thermochemical treatment of metals. Thermodynamic models describe the interaction between metals and components of saturating atmosphere and predict phase composition of diffusion layer. Diffusion models of kinetics of saturation of metals allow us to calculate the rate of growth of diffusion layer and regulation of its depth and structure. Structural models determine quantitative dependence between parameters of structure (grain size, dispersed particles, etc.) and mechanical properties. These models allow us to estimate the level of strengthening by control of structural specifics of strengthened layer. On the basis of this complex of models, new efficient technologies of surface strengthening are developed.     

Peculiarities of Electrochemical Behavior of Porous Carbon Electrodes of Supercapacitors in Aqueous Solutions of Salts of Alkali Metals

Electrochemical behavior of porous carbon electrodes with different densities (0.75 and 0.35 g/cm³) used in supercapacitors with aqueous solutions of lithium, sodium and potassium sulfates was studied. It was shown that Li₂SO₄ solution is the most suitable for high-density electrodes, whereas K₂SO₄ solution is better for low-density electrodes. Experimental data obtained by means of cyclic voltammetric and impedance curves demonstrate a mutual influence of the porous structure of the electrode materials and diameters of solvated and bare ions on the values of specific capacitance and resistance. This should be taken into account when an electrode/electrolyte system is chosen for high-efficiency energy storage devices.     

Foundations of energetics of electroplasmolysis of vegetable raw materials

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.     

飞机水平安定面后梁中段裂纹原因分析

在使用过程中,飞机水平安定面后梁中段出现裂纹。通过宏微观形貌观察、微区成分分析、金相检查和硬度测试,确定了水平安定面后梁中段的裂纹性质及失效原因。结果表明:后梁中段裂纹性质为剥层腐蚀裂纹,水平安定面后梁中段铆钉区腹板与后梁下缘条之间以及凸台与机身之间发生磨损导致剥层腐蚀裂纹。建议水平安定面后梁中段铆钉区腹板与后梁下缘条之间以及凸台与机身之间连接增加垫片,防止直接接触,并且对材料进行表面防护。     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

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.     

面向零件形状的计算机图形库的开发

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。     

Analysis of microporous structure of carbon adsorbents in terms of the theory of volume filling of micropores

A methodology of using the theory of filling the volume of micropores when evaluating the porous structure of carbon nanomaterials and adsorbents, as well as describing the adsorption of different species, is considered. Potentialities of the mathematical means of a theory of filling the volume of micropores when differentiating homogeneous and irregular microporous structure of activated carbon, determining the micropores’ parameters (their volume and size), evaluating the degree of heterogeneity of microporous structures, and describing adsorption over wide concentration range are analyzed. The perspectives of this approach, based on the theory of filling the volume of micropores, in the prognosis of the microporous structures’ parameters and the activated carbons’ adsorbability in the process of their synthesis are demonstrated. Original Russian Text ? G.A. Petukhova, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 2, pp. 170–176.     

阿那其根醇提取物对两种炎症模型作用机制研究

目的: 研究阿那其根醇提取物(EERAP)对二甲苯致小鼠炎症模型和脂多糖(LPS)诱导RAW264.7细胞炎症模型的影响。方法: 将50只小鼠,随机分为对照组(饮用水)、EERAP高剂量组(640 mg/kg)、中剂量组(320 mg/kg)、低剂量组(160 mg/kg)和阿司匹林组(120 mg/kg),采用二甲苯建立小鼠炎症模型,比较小鼠耳廓肿胀度及耳廓毛细血管通透性的变化,ELISA法测定各组炎症渗出液丙二醛(MDA)、超氧化歧化酶（SOD）的含量;LPS诱导RAW264.7细胞建立细胞炎症模型,ELISA法测定核转录因子kappa B（NF-κB）和肿瘤坏死因子-α（TNF-α）含量。 结果: 在二甲苯致小鼠炎症模型中,EERAP高、中、低剂量组均能抑制小鼠耳廓肿胀度,减少小鼠耳廓毛细血管通透性,减少渗出率,与空白对照组比较均有统计学差异(P<0.01);EERAP高、中、低剂量组均能降低血清中MDA含量（P<0.05）,显著升高SOD含量(P<0.01);在LPS诱导的RAW264.7细胞炎症模型中,EERAP在3.125～200 μg/mL范围内可降低TNF-α含量,而在2 μg/mL时也可以降低细胞NF-κB含(P<0.05),与阿司匹林组无统计学差异。结论: EERAP可能是通过抑制MDA、TNF-α和NF-κB的生成,升高SOD的水平,起到抗炎、抗氧化作用。     

Development of the technology of ultrasonic welding of components made of Capron tapes

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.     

Optimization of the profile of axisymmetric components of nozzles

A mathematical model of a turbulent boundary layer, describing the non-stationary non-isothermal flow of an incompressible gas in axisymmetric channels with the heat exchange is constructed. The equations of motion, continuity, and energy; the closing relationships for the coefficients of friction; and the heat transfer at the appropriate boundary conditions can be used for the analysis of the effect on the processes of friction and heat transfer with subsequent synthesis of phenomena – investigation of their combined effect and the determination of correlations between them, together with optimization of the profile of the surface with the flow around from the viewpoint of minimizing the thermal loading and energy dissipation.     

Evolution of misorientation spectrum of grain boundaries of submicrocrystalline molybdenum upon deformation under conditions of grain-boundary diffusion of nickel

Comparative investigations of the concurrent evolution of the structure and the misorientation spectrum of grain boundaries of submicrocrystalline molybdenum have been performed upon free annealing and under the creep conditions at a temperature of 1023 K. It has been established that changes in the misorientation spectrum of grain boundaries of submicrocrystalline molybdenum upon annealing and creep are observed concurrently with boundary migration. The grain-boundary diffusion of nickel upon annealing leads to an increase in the fraction of grain boundaries of the special type with Σ17a in the grain-boundary ensemble of submicrocrystalline molybdenum. Under the creep conditions grain-boundary diffusion fluxes of nickel atoms favor transformation of low-angle boundaries into high-angle boundaries and growth in the angle of misorientation of the high-angle boundaries of submicrocrystalline molybdenum to 45°–60°.     

Calculation of thermodynamic properties of metastable phases of the elements

A chemical bonding model that provides a method of predicting thermodynamic properties of metastable structures of the solid elements is presented. The method involves a Born-Haber-type cycle to calculate the difference in bonding energies between the room temperature stable structures and metastable structures. To carry out the calculations, spectroscopic data are used to determine the promotion energies from the ground state of the gaseous atom to the valence state corresponding to each structure. Such data are available for most elements, but in cases where experimental data are lacking, they are derived using predictive models. Combinations of promotion energies and heats of sublimation are used to determine bonding enthalpies. The contribution of the outer-shell s and p-electrons and the inner-shell d and f electrons to the bonding energies are considered taking into account the crystal field effect upon the bonding abilities of different d and f orbitals This paper was presented at the Thermodynamics and Phase Equilibria of Metastable Phases Symposium at the Spring TMS Meeting, March 1-4, 1992, in San Diego. The symposium was organized by Philip Nash, Illinois Institute of Technology, and Ricardo Schwarz,Los Alamos National Laboratory.     

国内钨精矿市场价格振荡原因分析

介绍了国内外钨精矿资源分布情况,分析了近阶段价格波动原因及后期走势。     

Development of mathematical models of superplasticity properties as a function of parameters of aluminum alloys of Al-Mg-Si system

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.