中国荚蒾属分布式样的数值分析     

徐炳声  缪柏茂 《中国科学院研究生院学报》1988,26(5):329-342

    本文用数值分类的关联分析方法对国产荚蒾属 Viburnum  所有72种的分布式样进行     了研究，旨在为中国植物区系分区的工作提供若干依据。中国荚蒾属的遗传变异中心是在中     南部而不在南部或西南部的事实强烈地暗示这是一个亚热带性质的属。  四川西南部是西部     特有成分最密集的地区。尽管横断山脉地区地形复杂，但那里只有几种荚蒾属植物。台湾的     种主要是亚热带性质的，而且大多数与大陆的种相同。这些种的分布式样展示我国台湾在区     系地理上与我国大陆或甚至日本有着比马来西亚地区更密切的亲缘关系。  本文总的结论大     体上与吴征镒教授关于中国种子植物区系的分区相符，但在某些次要方面有所不同。作者还    讨论了种的分布式样与自然地理、气候和植被的联系。  相似文献   

胡枝子种内地形梯度变异的分析     

徐炳声  李学禹  顾德兴 《中国科学院研究生院学报》1983,21(3):306-318

 Owing to the diagnostic characters used for distinguishing Lespedeza bicolor Turcz. from its allies L. formosa (Vogel) Koehne and L. elliptica Benth. ex Maxim. etc. beiny totally quantitative, and the great variability found in themselver as well, the group is therefore regarded as a taxonomically perplexing one. Therefore  quantitative measurements of the diagnostic characters, namely, the lengths of flowers (including standards and keels) and calyces (including calyx teeth and tubes) upon the total 307 herbarium sheets collected from 22 provinces and autonomous regions were made, and the data obtained were treated statistically (Table 1) and compared using methods of scatter diagram (Fig. 1--5),polygraph (Fig. 6) and topoclinal variation  (Fig. 7--10) in order to bring to light the differentiation pattern of these characters correlated to geographical distribution.      The diagrams of topoclinal variation (Fig. 7--10) of single characters represented by the lengths of calyx-teeth and corolla, or the calyx-teeth/calyx-tube ratio, between which exists a strong positive correlation, show a tendency of increasing gradation from northeast towards south-west. But the different combinations of morphological characters as shown in the scatter diagrams and more particularly in the polygraphs, make it possible to divide the Lespedeza bicolor group into the following three geographical types: (1) Bicolor type, with the distributional area of four provinces and one autonomous region of north-eastern and northern China; having the shortest (shorter than the calyx-rube) calyx-teeth of the whole group; with the standards of 71% herbarium materials exceeding the keels;  the  corolla length/calyx length ratio being 2.24; (2) Formosa type, with the distributional area covering six provinces and one autonomous region of eastern, south-eastern and southern China; with calyx-teeth nearly as long as calyx-tuges; with the keels of 69% herbarium sheets exceeding the standards, including all from whole  Guangdong  (Kwantung)  and  Guangxi (Kwansi); the corolla length/calyx length ratio being 2.59, the largest among the group; (3) Elliptica type, with the largest distributional area occupying ten provinces of south western, central, northwestern and eastern China and with most complicated morphologi- cal variation; the range of calyx-teeth length being 1.23--5.53 mm; with the keels of 80% herbarium sheets exceeding the standards, including all from whole Hubei (Hupeh) and Sichuan ( Szechuan ).      Since the above geographical types are either transitional or overlapping, it is probably appropriate to regard them as different geographical subspecies of a single species Lespedeza bicolor Turcz. Taxonomic treatments are then made herewith. A comparison of the main diagnostic characters and distributional patterns of the three subspecies in question is given in Table 3.  相似文献   

石蒜属的核型研究   总被引：3，自引：0，他引：3  

刘琰  徐炳声 《中国科学院研究生院学报》1989,27(4):257-264

本文对石蒜属Lycoris的12个种(包括亚种)和2个人工杂种进行了核型分析。 结果表明，石蒜属植物在染色体数目和核型上存在着较大的变异，而罗伯逊变化、杂交与多倍化是引起染色体变异的主要原因。  相似文献   

苹果属花粉形态特征及其分类学和进化意义   总被引：1，自引：0，他引：1  

贺超兴  徐炳声 《中国科学院研究生院学报》1991,29(5):445-451

 本文用扫描电镜观察了苹果属Malus 26种及5个杂种的花粉形态，描述了外壁纹饰形态特征的 变化类型，并对其进化趋势作了推论，指出外壁纹饰类型具属内分组意义。苹果属花粉在形状。大小、沟孔位置及数量、外壁纹饰等方面都十分相似。外壁纹饰的主要演化趋势可能是：由密的细条纹型到具有穿孔的、较少条纹型。杂种的外壁纹饰对于判断亲本种的关系有一定意义，属内种间的杂合导致了多倍体种、新变种、栽培种的大量出现，甚至是新种产生的方式。  相似文献   

忍冬科的数值分类初试   总被引：1，自引：0，他引：1  

徐炳声 《中国科学院研究生院学报》1983,21(1):26-33

 A numerical taxonomic study of Caprifoliaceae is presented. For the sake of ana- lyzing the resemblances between the 33 species or OUT’s selected at random from the total 13 genera of the family, a summation of 32 characters was employed in the numeri- cal analyses.  Raw data for each character were given equal weighting by condensa- tion in order to have adequate comparisons, and the characters were converted to 51 states, each with a new range of zero to one. Owing to the lack of sufficient data from other lines for numerical analyses, the characters used in this study were largely mor- phological.  The estimation of the coefficient resemblance between each pair or OUT’s was established using the association coefficient method.  The resulting values com- prise the 33×33 OUT’s basic similarity matrix.  The clustering technique used was unweighted pair-group method using arithmetic averages (UPGMA).      It can be stated that the scheme of phenetic relationships shown in the resultant dendrogram (Fig. 1) is on the whole in accord with the concepts hold by most current taxonomists, but with some noteworthy exceptions.  If the phenon line of tribal de- markation is drawn at the level of 0.6820, the OUT’s could be roughly divided into five groups or tribes.  The fact that the highest degree of correlation between Group I Sambuceae and Group II Viburneae on the one hand, and the great distance between them and the rest genera of the family on the other hand agrees well with the data obtained from morphological (Troll and Weberling,  1966),  anatomical  (Wilkinson, 1949, Metcalfe and Chalk, 1950), embryological (Moissl, 1941), sereological (Hillebrand and Fairbrother, 1970), and phytochemical (Bohm and  Glennie,  1971)  researches. These two tribes are most probably members of different phylogenetic origin. Trioste- um and Symphoricarpos both show their affinities  with  Leycesteria  of  Group  V Lonicereae instead of Group III Linnaeea  or Group II Viburneae as suggested by some taxonomists, and thus supports the opinion of Troll and Weberling (1966), who suggested that these two genera are members of the tribe Lonicereae.  The location of the phylogenetically uncertain genus Heptacodium in the dendrogram shows its close morphological similarity to the tribe Linnaeeae.       Because of the relatively small number of characters considered in this work, and “taxonomic judgement” was used in selecting these characters which appeared to be most “basic” to the classification of genera in the family, as well as the limitation of numerical taxonomy in itself, the resultant scheme of tribal relationships presented in this paper is by no means phylogenetic, but one that provides an excellent checkon ordinary taxonomic procedures.  相似文献   

Cognitive performance and academic achievement of Japanese, Chinese, and American children   总被引：3，自引：0，他引：3  

H W Stevenson  J W Stigler  S Y Lee  G W Lucker  S Kitamura  C C Hsu 《Child development》1985,56(3):718-734

Chinese, Japanese, and American children at grades 1 and 5 were given a battery of 10 cognitive tasks and tests of achievement in reading and mathematics. Samples consisted of 240 children in each grade in each culture. 2 major purposes of the study were to determine possible differences in cognitive abilities of Japanese, Chinese, and American children and to investigate the possible differential relation of scores on cognitive tasks to reading by children of the 3 cultures. Similarity was found among children of the 3 cultures in level, variability, and structure of cognitive abilities. Chinese children surpassed Japanese and American children in reading scores; both Chinese and Japanese children obtained higher scores in mathematics than the American children. Prediction of achievement scores from the cognitive tasks showed few differential effects among children of the 3 cultures. The results suggest that the high achievement of Chinese and Japanese children cannot be attributed to higher intellectual abilities, but must be related to their experiences at home and at school.  相似文献   

Simultaneous measurement of concentrations and velocities of submicron species using multicolor imaging and microparticle image velocimetry     

Jing-Tang Yang  Yu-Hsuan Lai  Wei-Feng Fang    Miao-Hsing Hsu 《Biomicrofluidics》2010,4(1)

We propose a novel approach to resolve simultaneously the distributions of velocities and concentration of multiple, submicron species in microfluidic devices using microparticle image velocimetry, and particle counting. Both two-dimensional measurement and three-dimensional analysis of flow fields, from the stacked images, are achieved on applying a confocal fluorescence microscope. The displacements of all seeding particles are monitored to determine the overall velocity field, whereas the multicolor particles are counted and analyzed individually for each color to reveal the distributions of concentration and velocity of each species. A particle-counting algorithm is developed to determine quantitatively the spatially resolved concentration. This simultaneous measurement is performed on a typical T-shaped channel to investigate the mixing of fluids. The results are verified with numerical simulation; satisfactory agreement is achieved. This measurement technique possesses reliability appropriate for a powerful tool to analyze multispecies mixing flows, two-phase flows, and biofluids in microfluidic devices.  相似文献   

Automated estimation of item difficulty for multiple-choice tests: An application of word embedding techniques     

Fu-Yuan Hsu  Hahn-Ming Lee  Tao-Hsing Chang  Yao-Ting Sung 《Information processing & management》2018,54(6):969-984

Pretesting is the most commonly used method for estimating test item difficulty because it provides highly accurate results that can be applied to assessment development activities. However, pretesting is inefficient, and it can lead to item exposure. Hence, an increasing number of studies have invested considerable effort in researching the automated estimation of item difficulty. Language proficiency tests constitute the majority of researched test topics, while comparatively less research has focused on content subjects. This paper introduces a novel method for the automated estimation of item difficulty for social studies tests. In this study, we explore the difficulty of multiple-choice items, which consist of the following item elements: a question and alternative options. We use learning materials to construct a semantic space using word embedding techniques and project an item's texts into the semantic space to obtain corresponding vectors. Semantic features are obtained by calculating the cosine similarity between the vectors of item elements. Subsequently, these semantic features are sent to a classifier for training and testing. Based on the output of the classifier, an estimation model is created and item difficulty is estimated. Our findings suggest that the semantic similarity between a stem and the options has the strongest impact on item difficulty. Furthermore, the results indicate that the proposed estimation method outperforms pretesting, and therefore, we expect that the proposed approach will complement and partially replace pretesting in future.  相似文献   

Extending the technology acceptance model of college learners' mobile-assisted language learning by incorporating psychological constructs     

Hui-Tzu Hsu  Chih-Cheng Lin 《British journal of educational technology : journal of the Council for Educational Technology》2022,53(2):286-306

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Beyond space and across time: non-finalized dialogue about science and religion discourse     

Pei-Ling Hsu 《Cultural Studies of Science Education》2010,5(1):201-212

This commentary dialogues with three articles that analyze the same database about science and religion discourse produced 17 years ago. Dialogues in these three articles and this commentary across space and time allow us to develop new and different understandings of the same database and situation. As part of this commentary, I discuss topics approached in the three articles including the collective nature of discourses, emotion, and constructivist view on learning. I draw on three essential concepts of the dialogical nature of utterance, the emotional-volitional tone and internally persuasive discourse informed by Bakhtin’s dialogism. In particular, I conclude that Bakhtin’s dialogism not only invites us to understand science learning discourse in a more holistic way but also encourages us to open up dialogues between science and religion that often are considered to be two hostile opponents.  相似文献