星叶草叶脉序的形态学及其系统学意义

在星叶草叶二叉分枝脉序中，网结脉中2条完全汇合叶脉与靠近脉中完全分离叶脉间未发现任 何形式的维管束汇合的中间类型，相反观察到了网结脉中不同程度的连接脉退化的痕迹，因此网结脉不可能由靠近脉形成；盲脉的出现与齿的退化、网结脉中连接脉的间断及非网结脉由分枝处间断等相关；上述事实表明星叶草叶的二叉分枝脉序应为一减化性状。     

动物医学专业形态学实验教学模式改革初探

动物医学专业形态学实验教学是动物医学本科教学体系的重要组成部分,为了提高实验教学效果,对形态学实验教学模式进行了改革:将动物解剖学、组织胚胎学和病理学的实验内容划分为基本实验项目模块和形态学综合实验模块,通过实验课程内容的整合,减少了实验内容的重复率,加大了学科内容知识点的联系,增加了综合性实验和研究性实验内容.问卷调查显示,本次所进行的动物形态学实验教学模式改革取得了较好的效果.     

Searching strategies for the Bulgarian language

This paper reports on the underlying IR problems encountered when indexing and searching with the Bulgarian language. For this language we propose a general light stemmer and demonstrate that it can be quite effective, producing significantly better MAP (around + 34%) than an approach not applying stemming. We implement the GL2 model derived from the Divergence from Randomness paradigm and find its retrieval effectiveness better than other probabilistic, vector-space and language models. The resulting MAP is found to be about 50% better than the classical tf idf approach. Moreover, increasing the query size enhances the MAP by around 10% (from T to TD). In order to compare the retrieval effectiveness of our suggested stopword list and the light stemmer developed for the Bulgarian language, we conduct a set of experiments on another stopword list and also a more complex and aggressive stemmer. Results tend to indicate that there is no statistically significant difference between these variants and our suggested approach. This paper evaluates other indexing strategies such as 4-gram indexing and indexing based on the automatic decompounding of compound words. Finally, we analyze certain queries to discover why we obtained poor results, when indexing Bulgarian documents using the suggested word-based approach.     

HPS: High precision stemmer

Research into unsupervised ways of stemming has resulted, in the past few years, in the development of methods that are reliable and perform well. Our approach further shifts the boundaries of the state of the art by providing more accurate stemming results. The idea of the approach consists in building a stemmer in two stages. In the first stage, a stemming algorithm based upon clustering, which exploits the lexical and semantic information of words, is used to prepare large-scale training data for the second-stage algorithm. The second-stage algorithm uses a maximum entropy classifier. The stemming-specific features help the classifier decide when and how to stem a particular word.     

Morphological priming effects on children’s spelling

Previous research has suggested that children in the early grades of primary school do not have much awareness of morphemes. In this study, a priming paradigm was used to try to detect early signs of morphological representation of stems through a spelling task presented to Portuguese children (N = 805; age range 6–9 years). Primes shared the stem with the targets and contained well-articulated, stressed vowels; the stems of the target words and pseudo-words contained non-stressed schwa vowels, which typically result in spelling difficulties. If priming proved effective, the well-articulated vowels in the prime should result in an improvement in the spelling of the schwa vowels. Primes were presented in two conditions: in only-oral or in oral-plus-written form. Effectiveness of priming was assessed by comparison with a no-priming condition. For both words and pseudowords, there was a significant interaction between priming effects and grade. No priming effects were detected in 6- and 7-year-old children; oral-plus-written priming produced higher rates of correct vowel spelling for 8- and 9-year-olds; only-oral priming was effective in improving the vowel spelling of 9-year-olds. Thus older children can use morphological information under priming conditions when the prime and the target are not phonologically transparent but there is no evidence to suggest that younger children do so.     

超临界CO2做发泡剂制备多孔尼龙66膜的研究

超临界CO2做发泡剂制备多孔膜尼龙66,通过X射线衍射、扫描电镜和水通量的方法对膜结晶度、孔形态和水通量进行了表征.超临界CO2的作用促使膜结晶度提高,得到胞腔状开孔结构膜.     

论“志”的语素化

＂志＂从古至今经历了语素化演变,即由自由成词语素演变为黏着的构词语素。这一变化主要表现在两方面：句法层面,单音词＂志＂的自由度从南北朝开始逐渐下降,到清代完全黏着化;词法层面,＂志＂作为构词语素构词力逐渐发达。是双音化推动了＂志＂的语素化进程。     

“政教合一”与“政教分离”——知识政治学视阈中的中古中西政治形态差异

“政教合一”与“政教分离”两种对立的政治结构模式,是中古时期中国与西欧政治形态差异的集中体现,二者本质差异在于关于政权的道理及其确证的区别,其本质差异的深刻原因便是二者拥有的知识基础不同。     

Toxic effects of Litsea elliptica Blume essential oil on red blood cells of Sprague-Dawley rats

Litsea elliptica Blume leaves have been traditionally used as medicinal herbs because of its antimutagenicity, che-mopreventative and insecticidal properties. In this study, the toxic effects of L. elliptica essential oil against Sprague-Dawley rat's red blood cells (RBCs) were evaluated. L. elliptica essential oil was given by oral gavage 5 times per week for 3 treated groups in the doses of 125, 250, and 500 mg/(kg body weight), respectively, and the control group received distilled water. Full blood count, RBC osmotic fragility, RBC morphological changes, and RBC membrane lipid were analyzed 28 d after the treatment. Although L. elliptica essential oil administration had significantly different effects on hemoglobin (Hb), mean cell hemoglobin concentration (MCHC), mean cell volume (MCV), and mean cell hemoglobin (MCH) in the experimental groups as compared to the control group (P<0.05), the values were still within the normal range. L. elliptica induced morphological changes of RBC into the form of echinoeyte. The percentage of echinocyte increased significantly among the treated groups in a dose-response manner (P<0.001). The concentrations of RBC membrane phospholipids and cholesterol of all treated groups were significantly lower than those of control group (P<0.001). However, the RBC membrane osmotic fragility and total proteins of RBC membrane findings did not differ significantly between control and treated groups (P>0.05). It is concluded that structural changes in the RBC membrane due to L. elliptica essential oil administration did not cause severe membrane damage.