剩余类环上矩阵的秩

定义了剩余类环上矩阵的秩及剩余类环上矩阵的初等变换,证明了剩余类环上行列式的运算性质,提出了求矩阵秩的一个推论。     

Performance of the S[... formula ...]2 Statistic for the Multidimensional Graded Response Model

S−χ2 is a popular item fit index that is available in commercial software packages such as flexMIRT. However, no research has systematically examined the performance of S−χ2 for detecting item misfit within the context of the multidimensional graded response model (MGRM). The primary goal of this study was to evaluate the performance of S−χ2 under two practical misfit scenarios: first, all items are misfitting due to model misspecification, and second, a small subset of items violate the underlying assumptions of the MGRM. Simulation studies showed that caution should be exercised when reporting item fit results of polytomous items using S−χ2 within the context of the MGRM, because of its inflated false positive rates (FPRs), especially with a small sample size and a long test. S−χ2 performed well when detecting overall model misfit as well as item misfit for a small subset of items when the ordinality assumption was violated. However, under a number of conditions of model misspecification or items violating the homogeneous discrimination assumption, even though true positive rates (TPRs) of S−χ2 were high when a small sample size was coupled with a long test, the inflated FPRs were generally directly related to increasing TPRs. There was also a suggestion that performance of S−χ2 was affected by the magnitude of misfit within an item. There was no evidence that FPRs for fitting items were exacerbated by the presence of a small percentage of misfitting items among them.     

半导体量子环的基态和激发态的能量的计算

利用B样条技术计算强磁场下二维量子环在不同角动量下的能谱及其量子尺寸效应.计算发现:量子环的能量在环半径r0=r00时出现一个极小值,当r0相似文献   

管培评协同的中等职业学校教师专业技能分级培训体系构建

以教师职业发展阶段理论、行为导向理论为指导,构建管办评分离下中等职业学校专业教师分级培训新机制,以解决中等职业学校专业教师实践能力偏低与自主发展动力不足,培训机构实施培训不规范、效果差等难题。通过制定统一的中等职业学校教师专业技能分级培训标准与评价考核标准,建立分层次、逐级培训与多元评价机制,强化培训质量控制与过程监督,形成管-培-评协同实施的中等职业学校教师专业能力提升新体系,切实提高中等职业学校专业教师培训绩效水平。     

美国引进翻车机安装中的端环焊接工艺

根据翻车机端环的特点及图纸与各类技术标准的具体要求,制定出了端环现场组对焊接工艺．采用了合理的焊接方法和检测手段,有效地控制了焊缝质量和焊接变形,保证了端环的几何精度     

吊环十字支撑动作的力学和肌电研究

吊环十字支撑是高级体操运动员在比赛中不可缺少的静止用力动作。运用力学和肌电对此动作进行研究,探索出完成动作的必要条件,由此确定正确的训练方法和有效程度,为广大高级体操教练员与运动员在制定训练计划与实施中提出有价值的参考。     

名辩逻辑提纲(下)

构建中国逻辑的横向体系 ,编写出教科书式的中国逻辑读本 ,是一项极具意义的学术工程。《提纲》乃这方面的闯新之作 ,计有“绪论”、“概念”、“辩说“、“余论”四章。“概念”“辩说”叙说中国逻辑的两大支柱部分 ;“绪论”“余论”阐述中国逻辑的总体、总貌和特色。     

高斯整环R(m~(1/2))及其商环

推广了文[1]、[2]的结论。当m≡1(mod4)时,证明了高斯整环R(m~(1/2))=Z[ω]的一些性质:R(m~(1/2))的商环的结构和R(m~(1/2))中质代数整数的判别条件。     

Application of Non-homogeneous Solution for Equations of Slender Ring Shells to Overall-Bending Problem of Ω-Shaped Bellows

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类氢施主杂质量子环能级和束缚能的B样条计算

利用B样条技术计算类氢施主杂质量子环能级和束缚能的量子尺寸效应．计算结果表明：量子环的能级E1随着抛物势ωh的增加而增大．E1-R0曲线存在极小值,极小值的位置r00随着ωh的增加而减小．束缚能Eb随着量子环半径r0的增加而单调快速地下降．在r0〈60nm区域,E1和Eb的量子尺寸效应很明显．在r0〉60nm区域,E1和Eb的量子尺寸效应不明显;在r0〈70nm区域,随着角动量m。从0增加到3,E1-r0和Eb—r0曲线的斜率发生剧烈的变化,E1的极小值的位置r00随着mc的增加而快速增大．在r0〉80nm区域,E1-r0和Eb-r0曲线分别会聚成一条线,E1和Eb不依赖于mc值的变化而变化;随着施主杂质的电荷增大,能级E1快速下降,E1-r0曲线的极小值的位置r00明显减小．库仑能不可以作为微扰项来处理．