Lateral Magnetically Modulated Multilayers by Combining Ion Implantation and Lithography

The combination of lithography and ion implantation is demonstrated to be a suitable method to prepare lateral multilayers. A laterally, compositionally, and magnetically modulated microscale pattern consisting of alternating Co (1.6 µm wide) and Co‐CoO (2.4 µm wide) lines has been obtained by oxygen ion implantation into a lithographically masked Au‐sandwiched Co thin film. Magnetoresistance along the lines (i.e., current and applied magnetic field are parallel to the lines) reveals an effective positive giant magnetoresistance (GMR) behavior at room temperature. Conversely, anisotropic magnetoresistance and GMR contributions are distinguished at low temperature (i.e., 10 K) since the O‐implanted areas become exchange coupled. This planar GMR is principally ascribed to the spatial modulation of coercivity in a spring‐magnet‐type configuration, which results in 180° Néel extrinsic domain walls at the Co/Co‐CoO interfaces. The versatility, in terms of pattern size, morphology, and composition adjustment, of this method offers a unique route to fabricate planar systems for, among others, spintronic research and applications.     

Structural organization of the major autolysin from Streptococcus pneumoniae

LytA amidase is the best known bacterial autolysin. It breaks down the N-acetylmuramoyl-L-alanine bonds in the peptidoglycan backbone of Streptococcus pneumoniae and requires the presence of choline residues in the cell-wall teichoic acids for activity. Genetic experiments have supported the hypothesis that its 36-kDa chain has evolved by the fusion of two independent modules: the NH2-terminal module, responsible for the catalytic activity, and the COOH-terminal module, involved in the attachment to the cell wall. The structural organization of LytA amidase and of its isolated COOH-terminal module (C-LytA) and the variations induced by choline binding have been examined by differential scanning calorimetry and analytical ultracentrifugation. Deconvolution of calorimetric curves have revealed a folding of the polypeptide chain in several independent or quasi-independent cooperative domains. Elementary transitions in C-LytA are close but not identical to those assigned to the COOH-terminal module in the complete amidase, particularly in the absence of choline. These results indicate that the NH2-terminal region of the protein is important for attaining the native tertiary fold of the COOH terminus. Analytical ultracentrifugation studies have shown that LytA exhibits a monomer <--> dimer association equilibrium, through the COOH-terminal part of the molecule. Dimerization is regulated by choline interaction and involves the preferential binding of two molecules of choline per dimer. Sedimentation velocity experiments give frictional ratios of 1.1 for C-LytA monomer and 1.4 for C-LytA and LytA dimers; values that deviated from that of globular rigid particles. When considered together, present results give evidence that LytA amidase might be described as an elongated molecule consisting of at least four domains per subunit (two per module) designated here in as N1, N2, C1, and C2. Intersubunit cooperative interactions through the C2 domain in LytA dimer occur under all experimental conditions, while C-LytA requires the saturation of low affinity choline binding sites. The relevance of the structural features deduced here for LytA amidase is examined in connection with its biological function.     

空间曲线的几何Hermite插值问题

在给定的 GC2 插值条件下 ,构造了一条空间四次 Bèzier曲线 (空间曲线的几何 Hermite插值问题 ) ,结果表明了四次 GC2 - Herm ite插值问题的解是局部存在的 ,并且有一个自由度 ;文章还讨论了逼近阶 ,并证明了局部解具有六阶逼近精度 .     

基于Tin改进的LiDAR滤波算法

现有典型的基于Tin的滤波算法只对本格网内的数据进行处理,没有考虑邻近地形的影响,使得滤波处理不能取得很好的效果。本文以待处理格网为中心,将待处理格网最低点与领域格网最低点构成三角网,再对格网内的数据与所在三角形的三个顶点进行比较,判断是否符合阈值来确定是否为地面点。实验的结果表明对改进后的三角网迭代的算法大大改善了滤波效果,提高了滤波处理结果的准确性。     

MCTF与改进SPIHT相结合实现的可分级视频编码方案

编码器首先将视频序列分组进行运动补偿时域提升滤波，然后将滤波形成的高低通帧分别做二维离散小波变换，再对小波系数进行改进的SPIHT编码，最后采用一种巧妙而高效的基于位平面的码流分配策略将SPIHT编码和运动矢量编码一起打包输出完全嵌入式的码流，实现时间和质量的可分级。     

数字图像中边缘算法的实验研究

边缘检测是图像处理、计算机视觉中的基础内容．也是至今仍未得到圆满解决的一类。目前图像处理大多数都是针对数字图像，本文对数字图像中几种具有代表性的边缘检测算法进行了理论分析，并通过编程实验，对各种算法进行实现，通过比较得出了各自的优缺点和适用范围。     

移动目标的快速识别算法

本文针对现有技术中存在的问题提出一种对复杂背景下的多个移动物体进行目标快速识别与跟踪的复合算法。该算法中采用对连续图像进行差影计算来确定移动目标区域，从而能去除复杂背景干扰，可以明显提高目标识别的速度和准确率。该系统已被实验证明其有效性和实用性．可广泛应用于监测与识别系统，也可应用于无人监控．无人自主操作等各种领域。本文中所提到的算法现为国家某重点项目中的关键技术。     

铁镍稀土自熔性合金粉末研究与应用

研究应用成本较低的铁镍稀土自熔性合金粉末材料代替镍基自熔性合金粉末材料。通过对铁镍稀土自熔性合金粉末材料显微组织分析、摩擦性能和结合强度试验以及实际应用等工作，表明铁镍稀土自熔性合金粉末材料具有熔焊性能好、结合强度高、综合性能优良、成本低等特点。     

智能阴极保护采集监控系统的应用与发展

目前金属材料广泛应用于油气管网的建设中,金属腐蚀问题备受关注,阴极保护技术是抑制金属腐蚀的一种非常有效的电化学保护手段。对阴极保护各项参数进行检测,能够保证阴极保护的有效性,降低金属发生腐蚀的风险。相对传统的人工检测方式,智能阴极保护采集监控系统能对阴极保护进行实时与同步监测,降低了测量误差并节省大量人工成本。随着科学技术的不断发展,现今有更多相关企业注重智能阴极保护采集监控系统的发展和建设,在获得经济效益与社会效益的同时推动了工业技术的不断创新与发展。