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从理论上分析了柱形弹簧振动系统的振动情况，并给出了柱形、锥形弹簧振动系统振动周期相对于弹簧质量、振动物体质量的实验结果。 相似文献
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先给出了一类一阶非线性时滞微分方程振动的充要条件,然后应用这个结果研究了一类非线性一阶中立型微分方程的振动性,所得结果推广了这方面的原有结果。 相似文献
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林文贤 《韩山师范学院学报》2015,(3)
作为机械、电子振荡的数学模型——泛函微分方程的振动性研究在理论和实际中都有着重要意义。对于二阶泛函微分方程的振动性已经有了许多结果,但对于三阶中立型泛函微分方程的振动性研究结果却很少。利用广义Riccati变换和Hardy-Littlewood-Polya不等式,研究一类具分布时滞的三阶非线性泛函微分方程的振动性和渐近性,建立了该类方程的所有解振动或收敛于零的两个新的充分条件,推广和改进了一些文献中的结果。 相似文献
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本文研究了一类高阶非线性中立型泛函微分方程的非振动解及振动解的渐近性质，得到了其非振动解及振动解的一些相关的渐近条件，推广了有关文献的结果。 相似文献
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本文考虑高阶非线性中立型时滞微分方程的振动性,利用积分平均方法,建立了这类方程解的振动准则,推广了文[1]对于二阶时滞微分方程的振动结果. 相似文献
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《International Journal of Educational Research》2001,35(4):373-389
This chapter presents and discusses the results of the study. The results are presented in three sections: results of the correlational analysis, results of the regression analysis, and results of the path analysis. In general the results suggest that family background is indirectly linked to GPA by virtue of its direct effect on study behaviors, verbal ability, and nonverbal ability. Similarly, the link between study behaviors and GPA is mediated through verbal ability and nonverbal ability. Family background and study behaviours consistently predicted nonverbal ability, verbal ability, and GPA, even after the effects of the other cognitive variables had been removed. 相似文献
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成绩分析是每次考试之后教师的首要工作,利用Office内置的VBA,实现了成绩分析,并且利用统计后的数据自动生成PowerPoint演示文稿,极大地提高了成绩分析的工作效率． 相似文献
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本文通过对糯玉米评价体系进行量化,以形成量化评定的结果,从产量和品质两方面,依次与原始评定结果及排序进行比较.最后得出:量化指标评定体系是目前较为科学、合理的方法. 相似文献
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丁念金 《集美大学学报(教育科学版》2002,3(1):22-25
与其他学习方式一样 ,研究性学习也必须追求一定的结果 ,只是研究性学习所应该追求的结果与其他学习方式所追求的结果不同。研究性学习的结果包括知识、科学探究能力、科学精神、独立性与合作性、社会责任感等基本方面 ,具有综合性、渐效性和非预定性等显著特点 ,这些特点给我们以重要的启示 相似文献
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Large‐scale assessment results for schools, school boards/districts, and entire provinces or states are commonly reported as the percentage of students achieving a standard—‐that is, the percentage of students scoring above the cut score that defines the standard on the assessment scale. Recent research has shown that this method of reporting is sensitive to small changes in the cut score, especially when comparing results across years or between groups. This study builds on that work, investigating the effects of reporting group size on the stability of results. In Part 1 of this study, Grade 6 students’ results on Ontario's 2008 and 2009 Junior Assessments of Reading, Writing and Mathematics were compared, by school, for different sizes of schools. In Part 2, samples of students’ results on the 2009 assessment were randomly drawn and compared, for 10 group sizes, to estimate the variability in results due to sampling error. The results showed that the percentage of students above a cut score (PAC) was unstable for small schools and small randomly drawn groups. 相似文献
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