Study of δ-hydrides in Ti-2Al-2.5Zr and Ti-4Al-2V alloys

The α alloy Ti-2Al-2.5Zr and near α alloy Ti-4Al-2V were hydrogenated to various levels. The morphology,orientation relation (OR), and habit plane of the hydrides were studied by means of transmission electron microscopy (TEM). It was found that in the two alloys most of the precipitates are δ-hydrides which have fcc structure with the lattice parameter a = 0.44 nm. Two basic orientation relationships and habit planes of the precipitates are determined. Twin structure was observed in both alloys.     

一种新型五自由度混联机床的运动及仿真分析

提出用两个二自由度并联机构相串联而成的混联机构作为主进给机构,外加一维运动的工作平台使之能实现五坐标数控加工的一种新型混联机床.其具有结构简单、易于控制的特点.对其机构进行了描述,应用螺旋理论分析了球形五杆机构的运动螺旋及其反螺旋,在此基础上求得其自由度;分析了该混联机床封闭的运动学正反解,用数值方法对其正确性进行了验证;并在此基础上以Visual C 为平台,利用OpenGL对其运动进行了仿真,对设计思想及设计细节进行了验证,为样机制造提供了可靠保证.     

原位生成Al2O3增强Al-4Mg基复合材料中的Al2O3/Al位向关系

综合搅拌铸造法和原位反应制备了Al2O3颗粒增强Al-4Mg基复合材料，并对制备的Al-4Mg基复合材料进行了透射电镜(TEM)观察分析，发现Al2O3／Al之间不存在固定的位向关系，但存在如下优先的位向关系：(1210)Al2O3∥(111)Al，[1012]Al2O3∥[112]Al，[2021]Al2O3∥[101]Al．     

XD反应合成Al3Ti,α-Al2O3和TiB2/Al复合材料的界面结构

借助于SEM和TEM研究了Al—TiO2-B2O3系热扩散反应法合成铝基复合材料的界面结构。结果表明：在B2O3与TiO2摩尔比小于1时，增强相由棒状的Al3Ti及颗粒状的TiB2和α-Al2O3组成。Al3Ti与基体的界面干净、相容性好，在基体中分布均匀；TiB2与铝基体界面干净，并存在以下位向关系：[231^-]Al∥[0001]TiB2，（204^-）Al∥（2420^--）TiB2，可成为基体结晶时的核心，细化基体晶粒；口一Al2O3与铝基体的润湿性差，被推挤到基体颗粒的界面呈偏聚状态，并存有孪晶现象，其孪晶面为（111），孪生方向为[112^-]。     

Effects of γ/γ interfacial structures on continuous coarsening of lamellar microstructure in TiAl alloy during aging

The effects of γ/γ interfacial structures on continuous coarsening of the fully lamellar microstructure in Ti-48Al alloy aged at 1 150 ℃ were investigated by using transmission electron microscopy(TEM). Continuous lamellar coarsening can be achieved not only by migration of interface faults(such as ledges, edges and curved interfaces) but also by migration and decomposition of perfect γ/γ lamellar interfaces. Thermal grooves, initiative positions of interfacial dissociation, can frequently form at the triple point junctions between the 120°-rotational ordered γ domain boundaries within γ lamellae and the lamellar interfaces. During the early stage of aging at 1 150 ℃, the interface migration and dissociation took place preferentially at the 120°-rotational ordered lamellar interfaces. Comparing the relative thermal stability of the true-twin, pseudo-twin and 120°-rotational ordered γ/γ lamellar interfaces shows that the 120°-rotational ordered lamellar interface is the most unstable. The reason of this phenomenon was analyzed through the comparisons of the interfacial energies and atomic arrangements of the three types of γ/γ lamellar interfaces.     

PRIMARY RECRYSTALLIZATION TEXTURES OF 70-30 BRASS ROLLED BY CROSS SHEAR ROLLING IN SINGLE DIRECTION

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Effect of change management capability in real-time environment: an information orientation perspective in supply chain management

Supply chain management (SCM) is an important strategic tool that requires careful planning and management. While the availability of real-time information is a critical aspect of an SCM system, it possesses a potential to disrupt supply chain participants. Thus, the success of an SCM system hinges on how well participants deal with changes taking place in a real-time environment. This study adopts the concept of the real-time enterprise to understand the role of change management on SCM performance based on the concept of the information orientation. The study empirically validated the role of change management on SCM performance.     

一种改进的融合关联词典的微博倾向性分析方法

大多数研究者对微博倾向性分析过多关注的是情感词、形容词和否定词,忽略了 关联词对其情感倾向的影响。为了提高微博情感倾向性分析的准确率,提出了融合关联词的微博倾向性分析方法,考虑微博文本中形容词、程度副词以及关联词之间的组合关系。 本文充分考虑了关联词的结构特点并在已有词典的基础上构建专门用于微博倾向性分析的微博词典、否定词词典和关联词词典,同时考虑到网络新词对微博倾向性的影响,还构建 了一个全新的网络新词词典。借助支持向量机（Support vector machine,SVM）将微博文本分为负向、正向和中性3 类,通过结合情感词典和SVM的方法提高微博文本倾向性分析的准确率。通过对COASE 2014 数据实验可以表明,本文方法对微博倾向性分析取得了较好的效果。     

Pose consensus in networks of heterogeneous robots with variable time delays

This paper proposes a novel pose (position and orientation) consensus controller for networks of heterogeneous robots modeled in the operational space. The proposed controller is a distributed proportional plus damping scheme that, with a slight modification, solves both the leader–follower and leaderless consensus problems. A singularity‐free representation, unit quaternion, is used to describe the robots orientation, and the network is represented by an undirected and connected interconnection graph. Furthermore, it is shown that the controller is robust to interconnection variable time delays. Experiments with a network of two 6‐degrees‐of‐freedom robots are presented to illustrate the performance of the proposed scheme. Copyright © 2014 John Wiley & Sons, Ltd.     

Face Orientation Normalization Using Eye Positions

Despite the fact that progress in face recognition algorithms over the last decades has been made, changing lighting conditions and different face orientation still remain as a challenging problem. A standard face recognition system identifies the person by comparing the input picture against pictures of all faces in a database and finding the best match. Usually face matching is carried out in two steps： during the first step detection of a face is done by finding exact position of it in a complex background （various lightning condition）, and in the second step face identification is performed using gathered databases. In reality detected faces can appear in different position and they can be rotated, so these disturbances reduce quality of the recognition algorithms dramatically. In this paper to increase the identification accuracy we propose original geometric normalization of the face, based on extracted facial feature position such as eyes. For the eyes localization lbllowing methods has been used： color based method, mean eye template and SVM （Support Vector Machine） technique. Experimental investigation has shown that the best results for eye center detection can be achieved using SVM technique. The recognition rate increases statistically by 28% using face orientation normalization based on the eyes position.