基于图像处理的玉米叶片姿态测量方法研究

为实现玉米叶片姿态的自动测量,针对玉米叶片形态特征,提出了基于图像处理的玉米叶片姿态自动测量方法。首先采用迭代方法对叶片图像细化,提取骨架图像上的各像素点,然后采用最大距离法计算叶片的弯曲度,通过测量叶片最高点与叶尖的垂直距离计算下垂度,最后对2种测量方法进行测试和分析。结果表明,所提出的叶片姿态测量的2种方法对样本叶片的测试准确率分别为92.4％和88.2％,能够有效描述和量化不同玉米品种的叶片弯曲程度,方法简单易行,且测量过程不需要标度校准。     

非精确条件下柑橘树树冠形状与采摘平台适应性关系研究

为减少采摘平台作业移动次数,尽可能使其适应树冠形状,扩大采摘面。以柑橘树为研究对象,通过对采集的照片进行分析处理,从不同成像方位和树高节点解析了样本树体树冠形状,建立了柑橘树冠形曲线数学模型,分析了柑橘树在目前种植管理模式下,树冠半径、冠幅等参数的变化趋势,讨论得出了适合柑橘园采摘平台作业的部分设计参数：升降高度应选取在0．5～1．0m区间内、外形尺寸参考1．5m×1．2m、最小转弯半径应不超过2．0m。     

氧化沟推流转轮半径对水流回流区长度影响的数值模拟

【目的】研究氧化沟推流转轮半径对氧化沟内流场回流长度的影响,为氧化沟工艺设计提供理论依据。【方法】采用气液两相流混合模型,并选取Realizable k-ε湍流模型封闭两相流时均方程,对氧化沟水力特性进行三维数值模拟,使用压力隐式算子分裂(Pressure-Implicit with Splitting of Operators,PISO)算法对速度与压力耦合进行求解,并采用VOF(Volume of Fluid)法对自由水面进行模拟。【结果】数值模拟得到了氧化沟推流转轮半径与水流回流区长度的关系表达式,表明回流区长度和直道段长度之比与叶轮半径和小弯道半径之比呈直线关系,并通过量纲分析法对其进行了进一步验证。【结论】氧化沟水下推流转轮是水流运动的最主要动力来源,转轮半径的大小对沟道内水流的流速以及流场结构有重要影响。     

Automatic feature extraction algorithm for porphyrin sensor array images

A feature extraction algorithm for porphyrin sensor array (PSA) images is presented. At the first step, it achieves an automatic tilt correction for PSA images based on radon transform. Then automatic mesh generation is applied to PSA images based on the method of combining projection binarization and mathematical statistics. The areas of porphyrin spots are locating by local threshold segmentation for the images which have achieved mesh generation. Finally, feature values of porphyrin spots are extracted by radius ratio method from the porphyrin spot areas. The algorithm solves the problem that identification of weak signal spots is quite difficult, and the extracted feature values are the maximum point to reflect the information of porphyrin spots. By ammonia, isoprene, aldehydes and other gases tests, the results show that the algorithm can effectively extract feature values of porphyrin spots in PSA images.     

榆木顺纹压缩弯曲技术

木材从力学角度上看是一种粘弹性材料 ,从结构上看又是一种多孔材料 ,木材的这个特性 ,可以使其进行简单的弯曲 ,但是要获得较小的弯曲曲率半径 ,首先应强化木材软化机理的研究 ,增大木材的塑性 ;其次研究木材软化处理后的顺纹压缩机理和压缩技术 ,使木材在顺纹压力的作用下 ,细胞壁中微纤丝之间产生滑移 ,导致木材细胞壁的壁层纵向产生褶皱 ,木材在弯曲力矩的作用下 ,弯曲时的受压面形成褶皱 ,受拉面形成展皱 ,在允许的形变范围内获得较小的弯曲曲率半径。本文研究结果表明 ,试件尺寸为 2 80mm× 1 6 5mm× 1 6 6mm时 ,经过水热软化处理后 ,顺纹压缩率达到 2 4 % ,试件回弹后的长度最小为 2 6 1 74mm时 ,弯曲的曲率半径最小为 4 2 5mm ,测试的试件平均值为 5 6 94mm。     

简单离子晶体离子半径比的计算

介绍了关于简单离子晶体中离子半径比的计算方法,给出了一个适用于各种类型简单离子晶体的一般公式,具有简便直观,易掌握之优点.     

Flow resistance and hydraulic capacity of water courses with aquatic weed growth. Part 2

The flow resistance is generally derived from fieldmeasurements, using the total wetted area of the cross-section.Less attention has been paid to the aquatic weed growth stageand often different resistance have been derived. In this paperthe flow resistance required in the Manning formula wascalculated from laboratory experiments and field data. A goodsolution appeared to be using the unobstructed part of the cross-section only and excluding the part covered by weeds. Apractical solution was found using the relative weed obstructionin the water courses to represent the weed growth. Weedobstruction was measured throughout the growing season. Thedata were obtained from water courses without any weedcontrol and also in sections where weeds were cleared twiceduring the growing season.     

Algorithm of Circle Analyse in Image Processing

To detect circles fast and correctly has wide application prospect in the field of computer vision and automatic inspection. The conventional Hough transform has the limitation of using too much computation and memory space, and restricted extracting parameter. Aiming at this problem, the authors bring forward a new detection method in allusion to the real-time requirement of detecting circle in simple, image. When the image does not intersect each other, they transform the image into binary image and then perform edge detection to it. After that the chain code of the image is acquired. Basing on that, the circularity of the image and radius of the circle more quickly are calculated and a satisfactory result is gotten.     

A PRELIMINARY STUDY ON THE FRACTAL DEMENSIONS OF LIME SAND CONCRETE

Fractal geometry is a branch of applied mathmatics in 1975,and it is used to describe the surface character of irregular bodies. This paper applies fractal demension to study the micropores structures of lime sand concrete,and concludes that it can be used to describe the microp-ores. Their radii are less than 100A. The fractal demensions of lime sand concrete are measured by MlP(mean indicated pressure) technique. The results have shown that the stronger the autoclaving schedules,the less the fractal demensions of lime sand concrete;the larger the water solid ratio(W/S),the larger the fractal demensions,and the calcium silicate ratio(C/S) has the effect on the fractal demensions of lime sand concrete. A pore structure parameter, mean pore radius is also proposed.