自编子程序提高老式数控机床的加工效率

针对老式西门子数控系统,编制了一些常用子程序,来实现典型孔、面加工的固定循环功能。详细阐述了几种典型孔、面加工子程序的编程思路和程序内容,并通过实例,介绍了子程序的编制及使用方法。这些子程序极大地提高了老式数控机床的编程效率并扩展了机床的加工范围和使用功能。     

V12M团簇的电子结构和磁性的第一性原理研究

采用密度泛函理论框架下的广义梯度近似（DFT／GGA）,对V13团簇及V12M掺杂团簇（M=Sc,Ti,Cr,Mn,Fe,Co,Ni,Y,Zr,Nb,Mo,Tc,Ru）的电子结构和磁性进行研究．通过对团簇的基态几何构型优化计算得到了团簇束缚能、电子结构以及磁矩的大小,系统地分析了V13和V12M团簇磁矩的形成机理以及电子结构与磁性的变化关系．发现掺杂团簇V12Fe和V12Ru为具有大束缚能和大能隙间隔的闭壳电子结构,V12Y团簇具有11μB的大磁矩,而其它掺杂团簇则表现为弱磁性．     

高吊灯电器箱压铸模设计

介绍了灯具电器箱铝合金压铸模设计及优化方案。     

区域企业集群的盟员选择方法研究

运用层次分析法对企业集群的盟员选择进行了探讨,给出了分析方法,运用评分几何平均法、规范列平均法对评判矩阵进行了计算,有效地确定决策矢量。使得企业集群可以科学合理而又迅速地选择到合作盟员,并大大提高企业集群的生产效益。本文给出了东莞模具集群企业盟主在选择最佳合作盟员的应用实例。     

First-principles calculation of phase equilibria and phase separation of the Fe-Ni alloy system

Theoretical investigation of the phase equilibria of the Fe-Ni alloy has been performed by combining the FLAPW total energy calculations and the Cluster Variation Method through the Cluster Expansion Method. The calculations have proved the stabilization of the LIE phase at 1：3 stoichiometry, which is in agreement with the experimental result, and predicted the existence of L1 0 as a stable phase below 550 K; this L1 0 phase has been missing in the conventional phase diagram. The calculations are extended to the Fe-rich region that is characterized by a wide range phase separation and has drawn considerable attention because of the intriguing Invar property associated with a Fe concentration of 65%. To reveal the origin of the phase separation, a P-V curve in an entire concentration range is derived by the second derivative of free energy functional of the disordered phase with respect to the volume. The calculation confirmed that the phase separation is caused by the breakdown of the mechanical-stability criterion. The newly calculated phase separation line combined with the L1 0 and L12Eorder-disordered phase boundaries provides phase equilibria in the wider concentration range of the system. Furthermore, a coefficient of thermal expansion （CTE） is attempted by incorporating the thermal vibration effect through harmonic approximation of the Debye-Gruneisen model. The Invar behavior has been reproduced, and the origin of this anomalous volume change has been discussed.     

First-principles calculations of phase equilibria and transformation dynamics of Fe-based alloys

Theoretical procedures of first-principles calculations of phase stability and phase equilibria are summarized. The present scheme is shown to be able to reproduce the transition temperatures with surprisingly high accuracy for Fe−Pd and Fe−Pt systems. The main emphasis of the present report is placed on the extension of the first-principles calculation to transition dynamics calculations. This is performed by combining the cluster variation method with the phase-field method via a coarse graining operation. The time evolution process of antiphase boundaries associated with L1₀ ordering for Fe−Pd system is demonstrated. This paper was presented at the International Symposium on User Aspects of Phase Diagrams, Materials Solutions Conference and Exposition, Columbus, Ohio, 18–20 October, 2004.     

悬浮床与固定床渣油加氢改质技术的区别

固定床渣油加氢改质技术是比较成熟的重质油加工手段,而悬浮床渣油加氢技术是较新的重油轻质化方案.以悬浮床加氢技术为主,详细地比较了两种技术在催化剂组成和性质,反应机理,工艺过程方面的区别,指出两种工艺联合使用可以充分发挥各自的优势,扬长避短,创造更大的经济效益.     

煤基清洁燃料——二甲醚产业初见端倪

从二甲醚的研究、生产、建设和应用等方面介绍了采用固定床一步法合成气制二甲醚和液相法生产二甲醚的工业化生产进程;论述了二甲醚作为石油工程的替代燃料实现产业化和市场化的可行性。     

Numerical study of coal particle cluster combustion under quiescent conditions

Behavior of ignition and combustion of coal particle cluster under a quiescent condition was numerically simulated by solving balance equations of mass and enthalpy with combustion kinetic models of volatiles and char. Two-flame structure, one flame penetrating into the cluster and the other moving out of the cluster, was predicted during the combustion of coal particle cluster. Effects of radiative heat transfer, group number, ambient temperature, coal particle size, and oxygen concentration on ignition and combustion of coal particle clusters were also analyzed. Simulations indicated that the gas volume fraction of coal particle cluster increases with time after devolatilization. Gas velocity passing through the cluster surface varied significantly at volatile liberation. The ignition time delay was reduced with the increase of ambient temperature. The cluster devolatilization rate and char burning rate increased while the ignition time delay decreased with the increase of ambient oxygen concentration.     

铜偏聚区的高分辨电镜分析

研究铜在钢中的时效强化和沉淀规律具有理论意义和实用价值。应用JEM-2010高分辨电镜研究了Fe-1．18Cu、Fe-1．55Cu高纯钢在时效时组织结构的变化规律,发现,含铜高纯钢固溶处理后,在550℃、650℃时效过程中,首先在铁素体晶粒中析出含铜偏聚区,铜原子偏聚在（001）α晶面上。在时效峰处为富铜的G、P区颗粒,其直径为4—20nm,呈层状的圆饼状,一般5—9层,富铜层和贫铜层相间分布,每一层厚度约为1—2nm。G、P区与铁素体基体半共格。G．P区的富铜区内及周边存在高密度位错和层错。在过时效初期,含铜偏聚区颗粒长大,偏聚区内富铜层和贫铜层的数量增多,富铜层厚度减小,位错密度降低。在铁素体基体上弥散分布的G．P区是含铜高纯钢时效强化的原因。