Strawberry Texture and Pectin Content as Affected by Electron Beam Irradiation

Fresh Tristar' strawberries were irradiated with electron beam irradiation at 0, 1, and 2 kGy. Fruit firmness decreased as irradiation dose increased. Water-soluble pectin increased and oxalate-soluble pectin decreased at 0 and 1 day after 1 and 2 kGy irradiation. Fruit firmness correlated with oxalate-soluble pectin content. Total pectin and nonextractable pectin were not affected by irradiation. The oxalate-soluble pectin content and firmness of irradiated strawberries increased slightly at the beginning of 2°C storage and then decreased as storage time increased. No changes occurred in water-soluble pectin, nonextractable pectin, or total pectin during storage.     

An adaptive digital image watermark algorithm based on gray-scale morphology

An adaptive digital image watermark algorithm with strong robustness based on gray-scale morphology is proposed in this paper. The embedded strategies include: The algorithm seeks and ex-tracts adaptively the image strong texture regions. The algorithm maps the image strong texture region to the wavelet tree structures, and embeds adaptively watermark into the wavelet coefficients corre-sponding to the image’s strong texture regions. According to the visual masking features, the algorithm adjusts adaptively the watermark-embedding intensity. Experimental results show the algorithm is robust to compression, filtering, noise as well as strong shear attacks. The algorithm is blind watermark scheme. The image strong texture region extraction method based on morphology in this algorithm is simple and effective and adaptive to various images.     

基于中文自然语言的纹理分类新方法

提出了一种新的基于中文自然语言纹理描述词的纹理分类方法,建立了自然纹理分类体系,并用最小二乘支持向量机对纹理进行分类,实现了纹理的视觉特征到语义描述的转换.实验结果证明,该方法在图像理解和基于内容的图像检索中有助于缩小纹理特征的数学描述和人类理解之间的"语义鸿沟".     

Relation between light trapping and surface topography of plasma textured crystalline silicon wafers

Currently, in the photovoltaic industry, wet chemical etching technologies are used for saw damage removal and surface texturing. Alternative to wet chemical etching is plasma etching. However, as for example, the linear microwave plasma technique, developed by Roth&Rau, has not been implemented in the photovoltaic industry for etching, because of the very low etch rate (<1 µm/min) and the high cost of ownership related to the etching process. In this study, different front surface textured crystalline silicon wafers obtained by means of the linear microwave plasma technique and the expanding thermal plasma technique are investigated in terms of weighted reflection by using reflectometry (250–1200 nm) to study the optical properties of the textures in detail. In addition, atomic force microscopy is used to measure the surface topography to determine statistical roughness parameters, as presented in this paper. Effective light trapping can be obtained by multiple reflections as well as by a graded layer, which leads to a diffuse front surface, or a combination of both. A graded layer can be described as a smooth transition with increasing refractive index from air to silicon with typical thickness of (200 ± 50) nm. We have found that the average plane tilt angle correlates to the measured weighted reflection. Moreover, we can determine from the aspect ratio whether the light trapping is effective by multiple reflections. From the roughness exponent, which is a measure for the micro roughness, we can determine whether the light trapping is effective by a graded layer. Copyright © 2013 John Wiley & Sons, Ltd.     

电铸镍药型罩的微观组织及织构分析

采用电铸方法制备纯镍药型罩 ,并用光学显微镜 (OM)、透射电镜 (TEM )、电子背散射衍射 (EBSD)技术对药型罩及爆炸变形后杵体进行观察分析。实验结果表明 ,电铸镍药型罩有良好的力学性能 ,在高速变形过程中发生动态再结晶。     

SnO2纳米材料制备技术的研究进展

综述了SnO2纳米材料制备技术的研究进展,报道了一种制备纳米纤维的新方法——热爆形变合成法,讨论了用该方法制备纳米纤维的基本条件。采用该方法制备出了SnO2纳米纤维,并进行了SEM和XRD分析。结果表明,SnO2纤维的直径约20-100nm,其X-射线衍射谱与标准的SnO2衍射谱完全一致。与其它方法相比,热爆形变合成法具有设备简单、操作方便、生产率高、产物无团聚等优点,稍加研磨就可获得长度不同的短纤维。但是,反应过程难以控制,这是热爆形变合成法的主要缺点。     

基于局部彩色二元模式纹理特征的人脸分类方法

针对现有的局部纹理特征在光照变化下的人脸分类准确率不高的问题,提出一种局部彩色二元模式纹理特征提取和表示方法.该方法首先求取多个信号通道的彩色向量的模,以减少单独对每个信号通道提取 LBP 特征导致的量化误差;其次提取任意两个信号通道之间的像素彩色夹角来减少光照变化的影响.对于给定的测试人脸图像集,通过 SVM 的二分类器投票得到人脸图像的分类.在 Color FERET 和 XM2VTSDB 人脸图像数据库上的实验证明该方法在光照变化下可以有效地分类人脸图像.     

适用于时间可伸缩的帧间快速编码算法

为实现时间可伸缩性,可伸缩视频编码采用分级B帧结构进行编码,但是该结构较大地增加了计算的复杂度。对此,本文深入分析了模式选择的基本原理,提出一种适合于分级B帧结构的快速编码算法,首先根据参考模式进行预测,然后根据宏块的运动和纹理预测可能的编码模式,排除可能性较小的模式从而提高编码速度。实验表明,本文算法在视觉质量和网络带宽影响很小的情况下,能够显著地提高编码速度。     

取向硅钢高温退火样品晶粒尺寸、取向及磁性能关系的研究

采用EBSD技术测晶粒取向,结合晶粒形貌观察,研究了普通取向硅钢高温退火样品晶粒尺寸、取向分布和电磁性能的关系。结果表明,异常长大的晶粒主要为Goss取向,小晶粒取向较杂乱,晶粒尺寸与晶粒取向有一定的相关性;晶粒尺寸和晶粒取向分别对铁损和磁感影响较大。     

利用灰度和纹理特征的SAR图像分类研究

多类别多特征量情况下的合成孔径雷达(SAR)图像的目标分类是一个难以解决的问题.从灰度和纹理模型出发,提出了综合利用灰度和纹理特征的目标分类方法.均值和方差是灰度模型中重要的特征统计量,而能量、熵、对比度、局部相似性和相关性是纹理模型中重要的特征统计量.灰度和纹理特征能确切地描述SAR图像中的目标.通过构造特征向量,定义向量之间的距离,并按照最小距离方法进行目标分类.以一定大小的窗口读入样本,提高了算法的运行速度和抗噪能力.理论上,窗口越大,特征向量值越接近真实值.窗口越小,边缘的分类精度越高.实验表明该方法较好地处理了多类别多特征量情况下的SAR图像分类问题,分类结果是有效的,这为SAR图像目标分类提供了一条简单可行的途径.