MG方法,FMG方法的自适应并行算法

本文给出多重网格(Multigrid,简称MG)法和完全多重网格(Full Multigrid,简称FMG)法的自适应并行算法。细网到粗网的插值转换均采用同步并行计算,且网格层间迭代转换是自适应的。实际计算表明:自适应同步并行MG、FMG算法可以实现,且后者比前者效率高。对于算法实现中的一些问题,本文亦做了讨论。     

Functionally graded semiconductor layers for devices application

We report on various aspects of the application of functionally graded materials (FGM) for devices fabrication. The broad spectrum of problems ranging from design and technology of graded structures to its characterization is discussed. The main attention is focused on the application of FGM as an active area of a new photo-detector. The influence of various profile distributions of AIIIBV grading layers composition and layers configuration on the photo-detector spectral characteristics are discussed.     

FMG粉烧结性能的研究

介绍了用FMG粉代替扬迪粉进行的烧结杯试验,探索了在保证烧结机利用系数、烧结矿性能的前提下,FMG粉适宜的配比。     

澳大利亚FMG粉矿烧结性能的试验研究

澳大利亚FMG粉矿属于褐铁矿,储量大且单烧品位高,提高其在烧结中的比例是企业降低生产成本的有效措施之一。烧结杯试验研究表明:FMG粉矿与结构致密的巴西CVRD粗粉、南非粉等进行合理搭配,选择适宜的工艺操作参数,通过实施高碱度厚料层、添加蛇纹石等工艺技术措施,更有利于改善FMG粉矿的烧结性能,在生产中大比例配加FMG粉矿是可行的。     

Pull-off test in the assessment of adhesion at printed wiring board metallisation/epoxy interface

It is shown that the value of adhesion strength at the metallisation/polymer interface can be determined directly from a printed wiring board (PWB) by a pull-off method. However, careful optimisation of the test geometry is required. In particular, the mechanical properties of the substrate are important. The use of flexible substrate in the test results in severe underestimation of the adhesion strength. There was a considerable stress peak at the edge of the test area, as shown by a finite element method (FEM) calculation with the flexible construction. This unevenly distributed stress decreases the force needed to detach the coating. In addition, if the test area is not defined to match the stud of the test equipment, the stress peak appears at the adhesive/coating interface rather than at the coating/metallisation interface. The experimental data and the examination of the fracture surfaces by scanning electron microscope (SEM) were consistent with the FEM results. In addition, the effect of environmental stresses on the adhesion was investigated. The environmental tests consisted of exposures to (1) thermal shock, (2) elevated temperature and relative humidity and (3) corrosive gases NO₂, SO₂, H₂S and Cl₂. The employment of embedded capacitors during the exposures revealed the diffusion of water into the epoxy, which weakened the adhesion. The corrosive gases induced irreversible deterioration of the dielectric material. An adhesion promoter enhanced the durability of the coating/Cu interface in the environmental tests. X-ray photoelectron spectroscopy was used to analyse the chemical states of the pre-treated copper surfaces.     

配加澳大利亚FMG矿粉对烧结矿高温强度的影响

为了研究澳大利亚FMG矿粉烧结的可行性,根据现场生产情况,进行FMG矿粉替代印度粉和地方铁精粉的模拟烧结实验及高温抗压强度实验研究.通过对烧结矿抗压强度与温度及FMG矿粉配比关系的分析,提出了适合现场生产的最佳配加比例.结果表明,在稳定生产的前提下,烧结原料中配加47%的FMG矿粉替代17%印度粉和30%地方铁精粉是可行的.