光源与物体色显现关系的仿真技术探讨

本文提出一种“利用原色漂移量调整法”确定当物体光谱反射率未知时光源与物体色显色关系。 利用该关系，通过微机真彩色数字图象技术对光环境进行仿真模拟。     

管线用高强韧性宽厚钢板的开发

本文回顾了舞钢高强韧性管线用宽厚钢板的研制开发过程，并结合生产工艺，对钢板性能作了全面分析，指导了钢管线钢的生产。舞钢X70级管线钢有较高的断裂韧性、良好的可焊性以及抗SSCC、HIC性能。舞钢正在进行技术改造，以进一步改善组织，提高性能、满足西气东输要求。     

热处理工艺对冲击曲线的影响

通过ＳＡ５１５Ｇｒ．７０钢的不同温度正火和１３ＭｎＮｉＭｏＮｂＲ钢正火不同温度回火试样的示波冲击试验，研究了不同热处理工艺对冲击曲线的影响。     

Effect of Post Annealing on the Microstructure and Magnetic Properties of NdFeB/α-Fe/NdFeB Thin Films

A series of nanocomposite thin films, composed of Nd2Fe14B and α-Fe, has been prepared by DC-magnetron sputtering combined ion beam sputtering onto Si (100) substrates. The effects of post annealing on the microstructure and magnetic properties of [NdFeB/α-Fe/NdFeB]-type thin films have been investigated. The X-ray diffraction (XRD) study showed that annealing of the films for 30min at temperatures 550,600,650,700℃ resulted in the appearance of diffraction peaks, characteristic for Nd2Fe14B tetragonal structure, α-Fe and Nd2O3 phases. The investigation using the Vibrating Sample Magnetometer (VSM) with a maximum applied field of 2 T indicated that with the increase of the annealing temperature, the magnetic properties of the multilayer films were improved and reached peak value at 650℃ (Hci=41.72kA·m-1, Mr/Ms=0.4, (BH)max=30.35kJ·m-3), after which the magnetic properties were decreased greatly. Along with the increase of the thickness of α-Fe layer from Tα-Fe16nm, the coercivity Hci, saturation magnetization Ms, and remanence ratio Mr/Ms all declined. As the Atomic Force Microscope (AFM) indicated, after being annealed at 650℃ for 30min, the sample was showed fine surface morphology with grain size 60nm≤dα-Fe≤80nm and 100nm≤dNdFeB≤150nm.     

连铸板坯的鼓肚变形与应力分析

以粘弹性薄板为模型，应用材料流变学理论及弹性薄板理论，分析计算了连铸板坯在钢水静压力与不均匀温度场作用下所发生的鼓肚变形与应力。计算结果与宝钢板坯连铸机的设计公式所得结果相吻合。此外，还得出了铸坯对夹辊的作用力。     

Extrapolated galerkin time finite elements

A new time finite-element method based on the extrapolation technique and the Galerkin time finite-element method is presented. In this method, the second-order governing differential equations of motion for dynamic problems are rewritten as a set of first order differential equations in state space. The standard Galerkin method is then employed for the temporal discretization. The algorithm is first-order accurate only. Based on the first-order Galerkin time finite-element formulation, the extrapolation technique is introduced to improve the order of accuracy. It is achieved by expressing the numerical amplification matrix of higher-order algorithm as a linear combination of the basic amplification matrices evaluated at selected instances of time. The matrices are combined with different weighting factors. The pairs of the selected instance of time and the corresponding weighting factors are free parameters. Unconditionally stable higher-order accurate formulations can be derived by properly choosing the free parameters. Algorithms up to fourth-order accurate are presented in this paper. Detailed analyses on stability, numerical dissipation and numerical dispersion are also given. Comparisons of the present algorithms with some well-known time-integration methods are presented to demonstrate the versatility of the present method, in particular its accuracy in the higher-order formulations.     

Representation and uniformization of algebraic transductions

This paper explores different means of representation for algebraic transductions, i.e., word relations realized by pushdown transducers. The relevance of this work lies more in its point of view rather than any particular result. We are aiming at giving specific techniques for obtaining, or perhaps explaining, decompositions of algebraic (and incidentally, rational) relations, relying solely on their “machine” definition rather than some complex algebraic apparatus. From this point of view, we are hoping to have demystified the heavy formalism employed in the present literature. Some of the novelties of our work are: the use of “stack languages” and “embeddings,” which eliminate the need of arbitrary context-free languages in our characterizations, the study of uniformizations for algebraic transductions and the use of the so-called stack transductions for exposing the anatomy of pushdown transducers.This work was supported by the Natural Science and Engineering Research Council of Canada grants R220259 and OGP0041630.     

宝鸡民营钛工业发展现状

介绍了宝鸡民营钛工业在新材料、新技术、新设备、新应用方面的进展,提供了市场需求与发展前景方面的相关信息,并对中小型钛加工企业的发展提出建议。