低分子有机酸对辣椒生长发育及叶片活性氧代谢的影响

采用盆栽试验与室内分析相结合的方法,研究了6种低分子有机酸和一种有机酸盐对辣椒生长发育和叶片活性氧代谢的影响。结果表明:柠檬酸、乙酰丙酸和有机酸钾处理不仅可显著提高辣椒根系干质量,增加辣椒vC含量,而且提高了辣椒的产量。甲酸、柠檬酸、乙酰丙酸和有机酸钾处理使根系活力比对照分别提高83%、93.8%、96.75%和99.5%。柠檬酸、乙酰丙酸和有机酸钾处理提高了辣椒叶片的SOD和POD活性,降低了膜脂过氧化产物MDA含量,延缓了叶片衰老。但是低分子有机酸处理对CAT活性的影响较小。

A Unified Tensor Level Set for Image Segmentation

This paper presents a new region-based unified tensor level set model for image segmentation. This model introduces a three-order tensor to comprehensively depict features of pixels, e.g., gray value and the local geometrical features, such as orientation and gradient, and then, by defining a weighted distance, we generalized the representative region-based level set method from scalar to tensor. The proposed model has four main advantages compared with the traditional representative method as follows. First, involving the Gaussian filter bank, the model is robust against noise, particularly the salt-and pepper-type noise. Second, considering the local geometrical features, e. g., orientation and gradient, the model pays more attention to boundaries and makes the evolving curve stop more easily at the boundary location. Third, due to the unified tensor pixel representation representing the pixels, the model segments images more accurately and naturally. Fourth, based on a weighted distance definition, the model possesses the capacity to cope with data varying from scalar to vector, then to high-order tensor. We apply the proposed method to synthetic, medical, and natural images, and the result suggests that the proposed method is superior to the available representative region-based level set method.

基于图像统计信息的去椒盐噪声算法

提出了一种基于图像统计信息的去椒盐噪声算法。该方法利用图像中心像素邻域的均值和方差来消除图像中椒盐噪声的影响。首先给出了这种算法的基本原理和实现,然后分别应用中值滤波算法、自适应中值滤波算法以及该算法对有椒盐噪声污染的图像进行滤波,并对实验结果进行比较和分析。实验结果表明,该方法不仅能够消除椒盐噪声,而且能够保持图像的特征信息。最后,对这种算法复杂度也进行了计算分析,并将其和中值滤波算法以及自适应中值滤波算法的复杂度进行了比较,证明该算法比中值滤波算法以及自适应中值滤波算法的复杂度低。