一种改进的二阶沃尔特拉滤波器LMS算法

本文给出了一种辨识二阶活尔特拉系统的新的LMS算法，数值模拟表明，这种算法比快速卡尔曼滤波器的计算时间短，收敛速度快。     

Fe-B合金激光熔凝形成非晶态机理探讨

本文对激光表面熔区的显微组织进行了热力学和动力分析，提出一个简化的熔池中温度分布的物理模型，分析了非晶态形成过程。用ＣＷＣＯ２激光扫描Ｆｅ—Ｂ合金表面，得到１３０μｍ～２００μｍ厚度的非晶层，并对激光低速扫描时熔区再结晶点阵常数变化的有关数据进行了对比，对激光非晶态形成的条件及有关工艺参数进行了分析和讨论。     

Removal of threading dislocations from patterned heteroepitaxial semiconductors by glide to sidewalls

We have shown that threading dislocations can be removed from patterned heteroepitaxial semiconductors by glide to the sidewalls, which is driven by the presence of image forces. In principle, it should be possible to attain highly mismatched heteroepitaxial semiconductors which are completely free from threading dislocations, even though they are not pseudomorphic, by patterned heteroepitaxial processing. There are two basic approaches to patterned heteroepitaxial processing. The first involves selective area growth on a pre-patterned substrate. The second approach involves post-growth patterning followed by annealing. We have developed a quantitative model which predicts that there is a maximum lateral dimension for complete removal of threading dislocations by patterned heteroepitaxy. According to our model, this maximum lateral dimension is proportional to the layer thickness and increases monotonically with the lattice mismatch. For heteroepitaxial materials with greater than 1% lattice mismatch, our model predicts that practical device-sized threading dislocation-free regions may be realized by patterned heteroepitaxial processing.     

Molecular statics simulations of buckling and yielding of gold nanowires deformed in axial compression

We use molecular statics simulations with the embedded atom method potential to delineate yielding (material instability) and buckling (structural instability) in gold nanowires deformed axially in compression. It is found that both local (stacking faults) and global instabilities occur when the gold nanowire yields but only global instabilities occur when the nanowire buckles. Furthermore strong surface effects reorient the lattice structure which significantly increases Young’s modulus in the axial direction and cause a nanowire of relatively small slenderness ratio (e.g., 14) to buckle. Upon complete unloading of the nanowires, the average axial stress and the total potential energy revert to their values in the reference configuration for the nanowires that buckled but not for the one that yielded.     

基于层次分析法的增材制造路径选择方法

增材制造路径对于成型质量、打印效率等具有重要影响。针对由多重因素造成的增材制造路径选择困难等问题，提出基于层次分析法的增材制造路径选择方法。通过调研得到17个主要评价指标，剔除耦合指标后归类为6大子指标，构建增材制造路径评价指标体系；以成型性能、开发性能、应用性能为主要指标，以常见的6种增材制造路径为备选方案，构建具有双层指标的增材制造路径选择层次模型，应用层次分析法相对权数计算的层位传递原理，对路径选择的多层判断矩阵进行一致性检验，确定备选增材制造路径方案总排序。分析结果显示分形路径综合性能最佳。     

无标度的层次分析法在教育评估中的应用

本文运用无标度的层次分析法计算教育评中指标体系的权重分配，此法不公能克服人为的主观型和期望型的影响，而且具有较强的科学性。     

A_l型Weyl群子根系轨道生成的格

利用W ey l群的性质及置换理论,讨论了Al型W ey l群作用下的子根系轨道生成的格.在同类型格中,研究了不同格之间的包含关系,给出了一个子根系是给定由μ生成的格L(μ)中一个元素的条件,最后讨论了按包含关系或反包含关系规定L(μ)的偏序时,L(μ)是否为几何格.     

MACSYM: A hierarchical parallel image processing system for event-driven pattern understanding of documents

MACSYM is a hierarchical parallel processing system for pattern understanding applications. It features event-driven parallel processing for knowledge-based understanding of document images. The system is composed of a master processor, slave processors and a large shared memory, and is equipped with versatile communication facilities. The parallel processing software system M.UM has been developed on MACSYM. It supplies a parallel processing language MacC, an extended version of C, and supports the programming for document image understanding. The Japanese newspaper layout understanding system EXPRESS is being developed on MACSYM. It analyzes a newspaper image and extracts articles in a few seconds.     

T(z) diagram and optical energy gap values of Cd1−zMnzGa2Se4 alloys

The T(z) diagram of the system Cd_1−zMn_zGa₂Se₄ was obtained from x-ray diffraction and differential thermal analysis measurements. It was found that at lower temperatures, a single phase solid solution occurs across the whole compositional range and values of lattice parameters were determined as a function of z. At higher temperatures, an order-disorder transition occurs, in the range 0 < z < 0.6 to a partially ordered tetragonal structure and for 0.6 < z < 1. 0 to a disordered defect zinc-blende structure. In the T(z) diagram, both the ordering boundary and the solidus curve appear to show discontinuities at z = 0.6, corresponding to the change in the disordered phase. It is suggested that the symmetries of the terminal compounds are different one from the other. Optical absorption measurements were made at 300 K to show the variation of the direct optical energy gap E_o with z, and again the values appear to divide into two parts below the above z = 0.6.