一种新的基于梯度方向直方图的图像配准方法*

构建了一种新的局部梯度方向直方图,同时定义了特征点的主方向,从而提出了一种具有旋转不变性的图像配准算法.首先采用高斯加权求模技术对特征点邻域内的像素的梯度作直方图统计,确定出具有旋转不变性和抗噪性的特征点主方向;然后用主方向作角度直方图统计,确定待配准图像之间的旋转角度.根据得到的特征点信息及旋转角度定义了特征点对互信息匹配准则,这样使得新配准算法对于图像间旋转角度的范围没有限制,获得了良好的配准效果.     

一种新的Kossel定向方法

本文提出一种新的Kossel定向方法。它只要求测出透射Kossel花样上的三个Kossel线交点之间的距离就能定向,从而减少了误差的来源,提高了定向精度。通常的透射Kossel照片定向误差为σ=±0.3°     

TiAl 合金中的γ→α析出转变行为

研究了Ti-48Al和Ti-48Al—0．8B合金中的γ→α析出转变，分析了α析出相的生长形态、晶体学特征、生长动力学及α／γ相界面结构。结果显示α相从γ相中析出有两种方式：一种是从γ晶粒内沿{111}，晶面以片状形貌析出，且α相与γ基体保持共格位向关系；另一种则是在γ晶界上通过不连续析出转变，以不规则的块状形貌析出，并向着晶界一侧与之无位向关系的γ晶粒内生长。添加0．8％(摩尔分数)B能显著降低γ晶粒内片状α析出相的形核率，并抑制α相生长。HREM分析表明：片状α相是在γ相的堆垛层错上形核，并通过“台阶-凸起-扭折”机制生长；α／γ相界面上复杂层错的存在及台阶形核率低是片状α相沿厚度方向生长缓慢的主要原因。     

微张力减径机轧后钢管产生青线的原因分析

分析出某厂14机架单独传动钢管微张力减径机在轧制过程中出现青线的原因是该减径机的主机架中滑板制造误差过大，机架受力倾斜造成的，整改后青线消失。     

工艺条件对YBCO厚膜基带晶粒取向的影响

用Ｘ射线方法研究了平行于基带表面的Ｎｉ（２０Ｏ），Ｎｉ（１１１），ＮｉＯ（２００）和ＮｉＯ（１１１）晶面的取向分数Ｗ。结果表明，随预热处理温度的提高，虽然Ｗ_（ＮｉＯ（２００））也会随之提高，但是区域重加热处理对提高Ｗ_（ＮｉＯ（２００））起着最重要的作用。９００℃预热处理之后，在１１００℃进行区域重加热可使Ｗ_（ＮｉＯ（２００））提高到０．９９以上。     

将开滦建成国内一流煤炭洗选加工基地的构想与实施

着重对开滦煤炭洗选加工的现状进行了分析和研究 ,总结了目前选煤系统存在的问题与差距 ,论证了开滦建设一流煤炭洗选加工基地的定位、主要内容 ,结合实际情况提出了实施建议。     

Online learning and fusion of orientation appearance models for robust rigid object tracking

We introduce a robust framework for learning and fusing of orientation appearance models based on both texture and depth information for rigid object tracking. Our framework fuses data obtained from a standard visual camera and dense depth maps obtained by low-cost consumer depth cameras such as the Kinect. To combine these two completely different modalities, we propose to use features that do not depend on the data representation: angles. More specifically, our framework combines image gradient orientations as extracted from intensity images with the directions of surface normals computed from dense depth fields. We propose to capture the correlations between the obtained orientation appearance models using a fusion approach motivated by the original Active Appearance Models (AAMs). To incorporate these features in a learning framework, we use a robust kernel based on the Euler representation of angles which does not require off-line training, and can be efficiently implemented online. The robustness of learning from orientation appearance models is presented both theoretically and experimentally in this work. This kernel enables us to cope with gross measurement errors, missing data as well as other typical problems such as illumination changes and occlusions. By combining the proposed models with a particle filter, the proposed framework was used for performing 2D plus 3D rigid object tracking, achieving robust performance in very difficult tracking scenarios including extreme pose variations.     

Unique clay orientation in the injection-molded bar of isotactic polypropylene/clay nanocomposite

In this article, the injection-molded bars of isotactic polypropylene/organoclay nanocomposite with different clay contents have been obtained via dynamic packing injection molding (DPIM). The oriented microstructure including layered nanoparticles and PP lamellae has been inspected through 2D-WAXS analyses along the sample thickness of the molded bars. Depending on the clay content and sample thickness, various oriented clay structures with nanoparticles uniplanar-axially oriented parallel to the surface of molded bar, or partially tumbled around the flow axis of the molded bar, or even a random orientation, could be observed. The observed orientation behavior of nanoparticles could be temporarily elucidated as the results of the sensitive response of layered nanoparticles to shear deformation and the structural recovery of clay network assisted by the electrostatic attraction existing between adjacent nanoplatelets.     

Improving oxygen barrier properties of poly(ethylene terephthalate) by incorporating isophthalate. I. Effect of orientation

The present study examined poly(ethylene terephthalate) (PET) and a series of statistical and blocky copolymers in which up to 30% of the terephthalate was replaced with isophthalate by copolymerization and melt blending, respectively. Some level of transesterification during processing of melt blends resulted in blocky copolymers, as confirmed by NMR. Random and blocky copolymers exhibited similar properties in the glassy state, including a single glass transition, due to miscibility of the blocks. However, random copolymerization effectively retarded cold‐crystallization from the glass whereas blocky copolymers readily cold‐crystallized to a crystallinity level close to that of PET. The polymers were oriented at four temperatures in the vicinity of the T_g and characterized by oxygen transport, wide‐angle X‐ray diffraction, positron annihilation lifetime spectroscopy, and infrared spectroscopy. Orientation of all the copolymers resulted in property changes consistent with strain‐induced crystallization. However, blocky copolymers oriented more easily than random copolymers of the same composition and after orientation exhibited slightly lower oxygen permeability, higher density, and higher fraction trans conformers. Analysis of oxygen solubility based on free volume concepts led to a two‐phase model from which the amount of crystallinity and the amorphous phase density were extracted. Dedensification of the amorphous phase correlated with the draw temperature. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1615–1628, 2005     

Orientation and relaxation in uniaxially-stretched poly(2,6-dimethyl 1,4-phenylene oxide) — atactic polystyrene blends

Infra-red measurements of the dichroic ratio of atactic polystyrene and poly(2,6-dimethyl 1,4-phenylene oxide) absorption bands provide a valuable method for the determination of orientation as well as relaxation of chains of both polymers during stretching of their compatible blends. Influence of strain rate, temperature of stretching, and molecular weight of the polymers on orientation of both polymer chains in blends containing up to 35% PPO has been studied. Orientation relaxation for both polymers has been analysed using Lodge's constitutive equation. Master curves have been obtained for PPO and PS in the blends at a reference temperature T₀ = T_g + 10°C. Results are interpreted in terms of an hindrance of relaxation of PS chains induced by interaction with a highly-oriented PPO network which slowly relaxes.