共查询到18条相似文献，搜索用时 78 毫秒
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孔亚峰 《赤峰学院学报(自然科学版)》2011,(5):9-10
为了更好的理解GL(3,2)是168阶不可解单群,本文利用有限群论的有关知识,运用分类讨论的方法,给出了GL(3,2)是168阶不可解单群一个新的证明. 相似文献
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在文献[2]中证明了线性变换群GL3(2)是汉明码A7的自同构群.文章证明了投射特殊线性群PSL2(7)(定义在有限域GF(7)上)和线性变换群GL3(2)是同构的.同时,得出了群PSL3(2)也是汉明码(-A)7的自同构群. 相似文献
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令 (M ,T)是一个带对合的光滑闭流形 ,不动点集为F ,本文的主要结果是决定了F =RP(1 )×HP(n)的对合的协边分类 . 相似文献
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利用覆盖映射和局部共形K(a)hler流形理论,证明了满足某些条件的局部共形K(a)hler流形一定为Vaisman流形的若干定理.如:Lee向量场为一个群S(eu,t∈R)作用诱导下的向量场一定为Vaisman流形.同时文中也给出判断Vaisman 流形的若干充要条件. 相似文献
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李永福 《湖州师范学院学报》1994,(6)
在这部分里,我们主要研究SO(n,R)的交换子群在S~(n-1)上的自然作用,并得出这些作用的轨道为S~(n-1)的极小子流形的充要条件(定理1) 相似文献
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设p :E→X是单连通光滑闭 4-流形X上的SU( 2 )主从 ,有限群G光滑作用于X和丛E使得p是一G -映射 .本文讨论了E上G -不变自对偶连络的模空间为光滑流形的G -不变度量的存在性问题 相似文献
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设L是闭定向光滑4－流形X上一复线丛，其第了陈类满足c1(L)=ω2(TX)mod2.G是有限群作为一保持定向的等距作用于X，同时也作用于L使得投影L→X是一G－映射，在X具有群作用的情形讨论了Seiberg-Witten理论，研究了Seiberg-Witten方程的generic扰动，在一定条件下证明了G－不变模空间为一光滑流形。 相似文献
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本文给出了双线性运算的定义,将文献[1]中的双线性算子与双线性形式加以联系,并在特定条件（V=R）下作一种统一,以利于认识对应的李群、李代数之间的关系,利于研究流形与子流形的结构。 相似文献
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郑玉美 《荆门职业技术学院学报》2000,(6)
自伽罗华建立群论 ,人们逐渐认识到群在各个领域中的重要作用 ,吸引了更多的数学家投入更多的热情去研究群论 ,使群论取得了如火如荼的发展 .我们把 1 870年以前的研究叫群论发展的早期 ,因为那时研究的基本上是置换群与变换群 ,而从克罗奈克 (Ｋｒｏｎｅｃｋｅｒ)发展抽象群的概念以后 ,人们开始关注抽象的有限群及无限群的研究 ,最后发展到连群群、李群的研究 .1 置换群1 1 注意到置换群的最早的数学家是拉格朗日、鲁菲尼及柯西 ,他们研究以ｘ1 ,… ,ｘｎ 为ｎ个根的一般ｎ次方程 ,其方法是引入一个辅助函数 :ｆ(ｘ1 ,… ,ｘｎ)这个函… 相似文献
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To improve students’ transitions between successive educational levels, continuing learning pathways are being designed and implemented in many countries. This study was carried out to examine the effects of the Green Lycea (GL) as critical cases of continuing learning pathways in vocational education in The Netherlands. The GL were compared with a traditional pathway (pre-vocational secondary education and secondary vocational education offered as separate programmes) in terms of students’ learning performance and transitions. GL students and comparable students following the regular pathway yielded the same mean final exam scores for four core subjects in the first phase of their educational programmes, despite the fact that GL students took this exam one year earlier than regular students because of the acceleration of the learning trajectory in the GL programme. Regarding the students’ transitions, the GL and the traditional pathway yielded comparable percentages of students who either did or did not obtain a pre-vocational secondary education diploma; For the GL, however, the percentage of students who proceeded in secondary vocational education was higher. To conclude, it seems to be possible to improve students’ transitions between successive educational levels (with their learning performance being an important precondition) through continuing learning pathways such as the GL. In this regard, GL design characteristics as described and examined in this study can be valuable ingredients for continuing learning pathways internationally as well. 相似文献
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李永福 《湖州师范学院学报》1991,(6)
设X、Y是任意n×n实矩阵,对于矩阵指数函数,一般说,e~X·e~Y≠e~(X+Y),除非〔X,Y)=0.当[x_1y]=(x+y)X-(x-y)Y时,本文通过浩繁的计算,终究得出一个具体的解析函数λ=f(x,y),使得e~X·e~Y=e~(X+Y+λ[X’Y])所得此公式,实际上正是一般线性群GL(n,R)的 2—Lie子群结构的一种表示. 相似文献
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从生成词库理论的角度看英语和汉语的差异 总被引：1，自引：0，他引：1
王健 《常熟理工学院学报》2009,23(9):92-95,122
Pustejovsky（1991、1995）提出的生成词库理论关注语言使用的创造性。生成词库理论对词汇的内部结构、语义生成机制等问题提出了新的观点。从生成词库理论的角度来看,英语和汉语有一些差异。 相似文献
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Ronimus Miia Eklund Kenneth Pesu Laura Lyytinen Heikki 《Educational technology research and development : ETR & D》2019,67(3):639-663
Educational technology research and development - This study investigates the effectiveness of a digital game—GraphoLearn (GL)—in supporting second-grade students who have persistent... 相似文献
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Learning from texts requires reflection on how far one has mastered the material. Learners use such metacognitive processes to decide whether to engage in deeper learning activities or not. This article examines how the lexical surface of specialist concepts influences their mental representation. Lexical encodings that are the concise wordings of a concept (e.g., tension headache or migraine for specific types of headache) provide immediate access to the underlying content. To understand learning contents appropriately, learners have to work on such lexical covers to gain insight into the underlying semantic meaning. It was assumed that a technical term??s origin (either German or classical Latin/Greek) is used systematically as a hint for further elaboration. 41 college students rated the difficulty, familiarity, competence, accessibility, and their knowledge of 17 German-language (GL) terms and their classical language (CL) synonyms. The influence of word frequency was controlled. As expected, results showed that GL terms were perceived to be less difficult than CL terms. Consequently, comprehension of these terms was rated more highly. Analyses of how lexical encoding influenced accuracy of participants?? comprehension judgments showed that participants?? comprehension ratings were less accurate for GL terms. Theoretical and practical implications for learning from written information are discussed. 相似文献
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K. Suzanne Scherf Marlene Behrmann Ruth Kimchi and Beatriz Luna 《Child development》2009,80(1):162-177
The developmental trajectory of perceptual organization in humans is unclear. This study investigated perceptual grouping abilities across a wide age range (8–30 years) using a classic compound letter global/local (GL) task and a more fine-grained microgenetic prime paradigm (MPP) with both few- and many-element hierarchical displays. In the GL task, contrary to adults, both children and adolescents exhibited a classic local bias. In the MPP, all 3 age groups evinced a bias to individuate the few-element displays; however, the ability to encode the global shape of the many-element displays at the short prime durations increased with age. These results indicate that the full process of garnering shape information from perceptual grouping, which is essential for the ability to do fast and efficient object recognition and identification, develops late into adolescence. 相似文献
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土壤呼吸及其组分随森林演替的变化对于长期碳循环模型及其地下碳储量至关重要.为了研究土壤呼吸随森林演替的变化及其影响机制,在2019年大兴安岭地区选取草地(GL)、白桦林(BF)、白桦与落叶松混交林(MF)、落叶松林(LF)4个不同演替阶段并对其进行研究.采用壕沟法测定自养(RA)和异养(RH)呼吸.结果 表明,GL、BF、MF和LF的土壤呼吸(RS)分别为3.11,5.68,5.54和4.69 μmol·m-2·s-1,RH分别为2.37,4.56,4.31和3.50 μmol·m-2·s-1,RA分别为0.74,1.12,1.23和1.19 μmol·m-2·s-1,GL、BF、MF、LF去除凋落物后Rs值分别为3.01,5.21,5.24和2.88 μmol·m-2·s-1.GL、BF、MF和LF中RA对Rs的贡献分别为23.79％,19.72％,22.20％和25.37％.演替阶段对Rs有显着影响(P＜0.05).回归分析发现,RA与细根生物量呈正相关(P＜0.01),RH与森林凋落物质量呈显著正相关(P＜0.05).试验的结果强调了演替阶段对土壤呼吸不同成分的重要性及其对估算森林碳汇潜力的重要性. 相似文献