1.5-环辛二烯的催化聚合

本文研究了1.5—环辛二烯在AlCl_3或AlCl_3与和C_2H_5B_1催化下的聚合反应,并探讨了该反应的机理。     

Sex differences in mental strategies for single-digit addition in the first years of school

Abstract

Strategy use in single-digit addition is an indicator of young children’s numeracy comprehension. We investigated Danish primary students’ use of strategies in single-digit addition with interview-based assessment of how they solved 36 specific single-digit addition problems, categorised as either ‘error’, ‘counting’, ‘direct retrieval’ or ‘derived facts’. The proportional use of each strategy was analysed as multi-level functions of school age and sex. In a first study (260 interviews, 147 students) we found decreasing use of counting and increasing use of direct retrieval and derived facts through years 1–4, girls using counting substantially more and the other two strategies substantially less than boys, equal to more than 2 years’ development. Similar results appeared in a subsequent study (155 interviews, 83 students), suggesting that the pattern is pervasive in Danish primary schools. Finally, we ask whether sex differences in strategy use is generally under-reported since many studies do not explicitly address them.     

一类2-连通无爪图的最长圈

讨论了一类2-连通无爪图的最长圈,若G是2-连通的无爪图,C是G的最长圈,G的阶为n,并且ξ(G)<1/2λ(G),则C(G)≥2/3(n+6).     

Magnaporthe oryzae MTP1 gene encodes a type III transmembrane protein involved in conidiation and conidial germination

In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Deltamtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.     

实施"1+1"体育教学对学生身体素质的影响

通过教学实践,笔者认为,在体育教学中实施“1 1“教学方案,能有效地激发学生学习体育的主动性和积极性,提高身体素质,发展体育能力,树立终身体育观念,学会科学锻炼身体的方法,促进学生的个性发展,为当前深化学校体育课程教学改革提供参考.     

含三唑和四唑的Schiff碱的合成及其植物激素活性

合成了6个3－氨基－1－H－1，2，4－三唑的Schiff碱和6个新的5－氨基－1－H－1，2，3，4－四唑的Schiff碱，通过UV、IR、^1H NMR和元素分析等对其结构进行了表征，生物活性测试试验表明，不少化合物都具有良好的植物激素活性，其中Ⅰ系列化合物具有优良的细胞分裂素活性，而Ⅱ系列化合物则具有很好的生长素活性与生根性能。氯代苯甲醛、噻吩甲醛和吲哚甲醛的Schiff碱活性最好。     

SPL(2|1)超代数单参数非齐次微分实现

本文引入了单一实参数，构造了SPL（2｜1）超代数的单参数4维初等表示，获得了SPL（2｜1）超代数单参数齐次微分实现和非齐次微分实现本文的研究结果，对深入研究SPL（2｜1）超代数单参数不可分解表示和不可约表示，构建SPL（2｜1）超对称精确可解模型，具有十分重要的意义。     

超细粉体二硫纶硝基菲略啉铁（II）配合物的磁性研究

报导了新近合成的二硫纶5－硝基菲咯啉铁（II）配合物FeLL‘(L=mmt^2-,malonitriledithiolate,L‘=5-NO2-phen,5-nitri-1,10-phenanthroline)透射电镜和粉末样品的变温磁化率，发现标题配合物是纳米级（颗粒直径约150－50nm）的微晶粉体，具有显著的顺磁性，形成四配位的高自旋态构型，并且呈现一定的自旋交叉性，探讨了这种配合物作为磁功能分子材料应用于高科技领域中的可能性。     

英语新闻语篇的批评性分析

近年来,西方的一些语言学家对语言学中的实证主义倾向提出质疑,认为语言不单纯反映社会,它直接参与社会事物和社会关系的构成;因而,语言学家必须重新认识语言的社会功能和语言学的任务,开展对大众语篇和其他非文学语篇的批评性分析,批评语言学从此诞生。     

L拓扑空间的局部超F1紧性

本文通过选择一种特殊的超F1紧性,给出了L-拓扑空间的局部超F1紧的定义,得出了局部超F1紧是闭、开遗传的,在开的连续的L-值Zadeh型函数下是保持的等.把分明拓扑空间中局部紧性的一些好的性质推广到L-拓扑空间中.