关键词： radiofrequency   Herbal Medicine   traceability   Vasoactive Intestinal Peptide   Paris polyphylla   Variance  

摘要： Paris polyphylla has been used by multiple nationalities as a traditional herb medicine to treat diseases in different regions of China. Since Paris quality is influenced by geographical regions, a fast and effective geographical traceability method is necessary. In our study, the geographical origin discrimination of 789 P. yunnanensis species from central, western, northwest, southeast and southwest Yunnan with 3rd to 8th cultivation years was carried out by chemometric of partial least squares discriminant analysis (PLS-DA), random forest (RF) and hierarchical cluster analysis (HCA) combined with attenuated total reflection-Fourier transform mid infrared (ATR-FTMIR). The results indicated that principal component analysis (PCA) was successfully used as an exploration data analysis method to remove outliers. Additionally, classification ability of PLS-DA model, established by variable importance for the projection (VIP), was similar to that of PLS-DA model, which indicated that raw ATR-FTMIR spectra contained abundant redundant information useless for classifying samples. For each model, the range of VIP values of PLS-DA is wider than the range of the important variables of RF, and PLS-DA was more time-efficient and high-ability than RF model. Besides, the geographical origin PLS-DA classification model with all collected samples was used to verify the results with accuracy rates of calibration set and validation set of 98.34% and 93.78%, respectively. HCA verified that the impact of geographical origin on P. yunnanensis characteristics is greater than that of the number of cultivation years. In short, PLS-DA model can assure the accuracy and limit time for identification analysis of cultivated P. yunnanensis quality assessment from different geographical origins.

关键词： 数学文化   算法   人类文明   中学数学   学习   领悟  

摘要： 数学作为一种先进的文化,对人类文明的进程起着不可磨灭的作用。近年来,数学文化不断地渗透在中学数学的学习中,本文以算法为案例进行分析,希望对大家了解并领悟数学文化试题能有所帮助。

关键词： 算法   实验教学   高中数学   优课   策略  

摘要： 算法是高中数学的重要内容,在算法的教学过程中结合上机实验既是创新教学之举,也与"一师一优课,一课一名师"活动中的教学设计要求相吻合.在相关优课的开发过程中,应该注意自主性、探究性、互动性、合作性和评价性等策略.

关键词： 装配零件集   装配约束件   矩阵算法   约束矩阵   线性递推算法   WMS数学模型  

摘要： 为了获得产品的最优自动装配顺序,根据自动装配原理提出装配零件集和装配约束件的概念,运用矩阵算法和线性递推算法构建装配顺序的WMS数学模型。依据产品装配结构特征和装配约束件约束特征分别构建装配关联矩阵和装配约束矩阵,进而获得理论装配工艺数和顺序序列。运用层次分析法确定装配因素的影响权重系数和对各影响因素值进行无量纲化处理,获得产品的装配顺序评价模型。运用此模型即可便捷地确定产品的最优自动装配顺序。以一自动-手动水龙头装配为例进行实证研究。结果表明上述理论方法可行和实用。

关键词： 空间分辨力   单光子发射型电子计算机断层扫描仪(SPECT)   空间分辨性能  

摘要： 目的:分析单光子发射型电子计算机断层扫描仪(SPECT)空间分辨性能,为制定SPECT性能检测标准时数学函数算法的选取提供参考。方法:使用SPECT通用检测模体获取固有空间分辨力、系统空间分辨力及全身平面空间分辨力3个性能参数的医学数字成像和通信(DICOM)图像,对3个性能参数随机获取10次测量数据,分别采取抛物线算法和高斯算法对数据进行拟合计算测量,并分析两种数学函数算法结果的差异。结果:所获SPECT的3个性能参数高斯算法拟合相关系数平方(R^2)值为0.974～0.999;SPECT固有空间分辨力、系统空间分辨力和全身平面空间分辨力的检验P值分别为0.0001、0.057和0.075。结论:对于SPECT空间分辨性能的分析可采用抛物线法进行分析,对于系统空间分辨力应该采集256×256矩阵的数据。

关键词： 探究   算法   算理   计算能力  

摘要： 数学计算能力的培养,不仅是小学数学教学的重要内容,也是继续学习数学和其他自然学科的基础。在“两位数减一位数退位减法”的设计与教学过程中,教师让学生摆小棒,借助计数器理解减法拆、借过程中计数单位的变化,明白“借一当十”这一算理;借助已有减法的经验,自主探索两位数减一位数的笔算过程,在对比几种不同计算的过程中掌握算法,培养学生的计算能力。

关键词： 小学数学   算法   多样化   教学质量  

摘要： 近年来,随着我国新课程改革的不断推进,小学数学教学越来越重视学生的创新思维与综合能力培养,以强化学生的核心素养,实现学生全面发展的教育目标。数学算法教学是小学教育体系中的重要组成部分,采取多样化的算法教学理念,更是现代教育所提倡的教育标准,其不仅能有效培养学生的发现问题、探究问题、解决问题的能力,还能进一步增强学生的知识运用水平,对学生今后的长足发展具有重要影响。现阶段,如何在现代教育背景下,提高小学数学教学的课堂质量,强化学生的数学能力,已经成为当今社会广泛关注的首要课题,并受到了人们的高度重视。主要就小学数学算法多样化展开探讨,希望能够对日后的相关研究有所帮助。

关键词： Sparse linear algebraic equations   Aggregation based algebraic multigrid   Preconditioner   Krylov subspace method   Graph partitioning  

摘要： Aggregation based algebraic multigrid is widely used to solve sparse linear systems, due to its potential to achieve asymptotic optimal convergence and cheap cost to set up. In this kind of method, it is vital to construct coarser grids based on aggregation. In this paper, we provide a new aggregation method based on coordinates partitioning recursively. The adjacent graph of the original coefficient matrix is partitioned into sub-graphs and each sub-graph is recursively partitioned until the minimal number of nodes over the subgraphs on some level is small enough. In this way, a hierarchy of grids can be constructed from top to bottom, which is completely different from the classical schemes. The results from the solution of model partial differential equations with the preconditioned conjugate gradient iteration show that the new algorithm has better performance and is more robust than the widely used classical algorithms in most cases. (C) 2018 Elsevier B.V. All rights reserved.

关键词： 有机整合   教学资源   沟通   算理   算法  

摘要： 在数学教学中,教师应根据具体的教学内容和学生的认知规律,从学生的实际情况出发,顺学而教,使每位学生都能学到基础的数学知识和基本的数学技能,提高学生解决问题的能力。