Study of the external morphology of Leptodora kindtii Focke, 1844 (Crustacea: Branchiopoda: Haplopoda), with notes on its relation to Cladocera and on conspecificity of populations of the species over the Eurasian range

Leptodora kindtii is a peculiar carnivorous crustacean widely distributed and occupying a prominent position in the freshwater planktonic communities. This species was originally found and described in the 1840–1860s and since then it has been a subject of numerous studies, morphological, embryological, behavioural, and ecological, which elucidated various aspects of its body structure and mode of life. Nevertheless, analysis of the literature and personal investigation of material on the species have led to the conclusion that the morphology of the species was not studied properly and the previous data might be incorrect and inconsistent, which obstructed proper understanding of its phylogeny, taxonomic position, and habits. In the present investigation, the external morphology of L. kindtii is described and analysed in detail, from comparative morphological and eco‐morphological aspects. Also, the morphological features of representatives of the species from different populations over the vast area of its Eurasian range have been studied with respect to their intra‐ and interpopulational variability and taxonomic significance. It has been shown that the majority of populations of L. kindtii from Europe to the Far East of Russia do not display any significant morphological differences, which testifies to their conspecificity. Only a small set of adult specimens from Lake Bolon (the Amur River basin, Far East of Russia) differed considerably from others in their small size and body proportions which implies the occurrence of another species of the genus in this region to be studied and validated in the future together with the enigmatic cave species L. pellucida Josef. In spite of high morphological peculiarity, L. kindtii possesses a number of “core” characteristics, which undoubtedly show its close relationship with other mostly small branchiopods (Ctenopoda, Anomopoda, Onychopoda) traditionally united in the taxon Cladocera whose validity has also been supported by modern molecular‐genetic studies.     

抗白粉病硬簇麦-Am3杂种后代的形态学及细胞学鉴定

对硬簇麦与Am3的杂交后代进行白粉病抗性鉴定,从中选出9个抗白粉病的种质系。形态学鉴定结果表明,9个种质系的形态学特点明显不同于双亲,主要农艺性状表现较好。细胞学鉴定结果表明,9个种质系的根尖细胞染色体数目均为42,花粉母细胞减数分裂中期I基本形成21个二价体,偶尔有单价体或多价体出现,但频率较低,相对紊乱系数较小,说明9个种质系在细胞学上已基本稳定。     

词的形态理据与词汇习得刍议

对大多数英语和非英语专业的中国大学生说来,词汇习得是他们学习英语过程中的难点。这主要是因为学生仍以机械记忆为主,难记易忘。本文引入形态理据的概念,并以实例分析为主,具体探讨了词的形态理据和多词素分解与词汇习得的密切关系,以期矫正和优化词汇的习得方式。     

单词型术语的结构自动分析

根据计算术语学的原理，使用有限状态转移网络对单词型术语进行自动分析。首先以英语术语为例，介绍了有限状态转移网络的基本原理和分析过程，然后分别讨论了德语、法语和汉语的单词型术语的自动分析问题，最后讨论了分析结果的表示形式。     

An Algorithm for Ship Wake Detection from the SAR Images Using the Radon Transform and Morphological Image Processing

1. INTRoDUCTIONGreat advance in SAR imaging technology has promoted the imag6 data study from ajl-weather space--borneobserwtions. lt has become known that a moving ship may generate surface perturbation to form srvcalled V-shaPed Kelvin arms and turbulence wakes, which can be sensed from SAR obserwtions. Bright or dark streaksof radar echo (backscattering) in SAR image can be identified as a detection of a moving ship. IIiformationabout the ship location, moving direction, and even i…     

一种基于改进 Surendra背景更新算法的运动目标检测

建立背景模型时,采用动态阈值的方法,以减少噪声和光照强度变化等外界环境的影响;在运动目标检测中,针对传统方法检测到的运动目标偏大的问题,提出一种改进的三帧差分检测方法.在形态学处理过程中,采用自适应方法选择结构元素的大小,对二值图像进行去噪处理,以得到平滑图像.实验证明,改进后的方法与传统背景模型建立方法相比,能更准确地检测到运动目标区域,并实时更新背景模型     

安全玻璃碎片图像的边缘检测方法比较

分析了安全玻璃的碎片状态试验后采集到的数字图像的灰度分布特点,并且应用几种不同的边缘检测方法来对该类图像进行边缘的检测,最后对实验结果进行了分析和比较．     

英语语素及语素变体的音位制约和形态制约研究

语素既是语言中音义结合的最小单位,又是语法分析的最小单位.它可分为自由语素和粘着语素.通常情况下,语素在任何环境中只有一种形式,但也有一些语素的形式是变化的.语素的变体会受到语音和形态的条件制约.英语语素是英语的核心内容之一,通过掌握语素知识,学习者可以从形态学的角度去了解和学习英语词语的内部结构和构词规律,从而有助于学习者能更准确地用词、更有效地记词.     

一种新的应用于凹体渐变的广义形态变换方法

在形态运算的基础上提出了一种广义形态的变换方法,首先将被渐变物体进行凸剖分,对得到的子凸集进行匹配映射后再进行形态和插值,然后再将各变换结果合并即得到最终结果,实验证明,此广义形态变换方法可以很好地解决非同构物体和凹体间的渐变,效果自然、质量好、速度快、自动化程度高,可用于非体运动描述及二维动画关键帧的内插等领域。