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高职师范类数学教育专业数学建模课程改革的一些思考
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作者 赵绚 杨林 《齐齐哈尔师范高等专科学校学报》 2021年第3期103-105,共3页
针对当前高职专科师范类数学教育专业的学生学习基础和数学建模课程培养目标之间的不相适应这一问题,结合学校特点和专业特色,提出了三种改革途径,促进数学建模课程的教学改革,逐步培养学生分析解决实际问题的能力,提高学生的数学素养,... 针对当前高职专科师范类数学教育专业的学生学习基础和数学建模课程培养目标之间的不相适应这一问题,结合学校特点和专业特色,提出了三种改革途径,促进数学建模课程的教学改革,逐步培养学生分析解决实际问题的能力,提高学生的数学素养,进而全面推动提升学生的素质教育。本文对师范类教育中数学教育专业数学建模课程教学改革的一些思考,对课程教学与培养目标之间的矛盾进行了分析,并提出了一些新的改革措施,能对数学建模课程改革有积极的探索意义。 展开更多
关键词 数学建模 教学改革 数学素养 数学教育
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去合金化制备纳米片阵列和纳米球颗粒多孔锡
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作者 赵旭 梁丹莹 +2 位作者 张聪惠 宋国栋 王言眸 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2021年第10期3670-3676,共7页
以Mg_(89)Sn_(11)(二元合金)为前驱体合金,在腐蚀介质中通过去合金化方法制备了纳米片阵列和纳米颗粒形貌的多孔锡。通过调整腐蚀介质和腐蚀时间,研究了纳米多孔锡的形貌结构以及去合金化程度的影响因素。结果表明,在酸性腐蚀介质中去... 以Mg_(89)Sn_(11)(二元合金)为前驱体合金,在腐蚀介质中通过去合金化方法制备了纳米片阵列和纳米颗粒形貌的多孔锡。通过调整腐蚀介质和腐蚀时间,研究了纳米多孔锡的形貌结构以及去合金化程度的影响因素。结果表明,在酸性腐蚀介质中去合金化,能够获得双连续结构的纳米多孔锡结构。其中,在质量分数0.1%H_(3)PO_(4)溶液中,孔壁由不连续的纳米球颗粒堆积而成,而在0.1mol/L HCl溶液中,孔壁为纳米片结构,形成了纳米片阵列的多孔锡;而在中性的NaCl溶液中,同样成功制备出了均匀的纳米片状阵列多孔锡。在质量分数5%的NaCl中,随着去合金化时间的延长,多孔锡形貌从均匀的纳米片阵列多孔结构转变为团簇状的纳米多孔结构。去合金化1h时,表面形成了均匀的纳米片阵列多孔结构,6h后表面开始形成不连续的团簇状多孔形貌,并最终演化为连续起伏的片状纳米锡多孔结构,其孔径平均尺寸保持在50nm。通过对去合金化工艺进行调整,制备了不同形貌的纳米多孔锡结构。 展开更多
关键词 纳米多孔锡 去合金化 双连续多孔结构 纳米片阵列
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The Structural Characterization and Antigenicity of the S Protein of SARS-CoV 被引量:5
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作者 JingxiangLi ChunqingLuo +18 位作者 YajunDeng YujunHan LingTang JingWang JiaJi JiaYe FanboJiang zhaoxu WeiTong WeiWei QingrunZhang ShengbinLi WeiLi HongyanLi YudongLi WeiDong JianWang ShengliBi HuanmingYaug 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2003年第2期108-117,共10页
The corona-like spikes or peplomers on the surface of the virion under electronic microscope are the most striking features of coronaviruses. The S (spike) protein is the largest structural protein, with 1,255 amino a... The corona-like spikes or peplomers on the surface of the virion under electronic microscope are the most striking features of coronaviruses. The S (spike) protein is the largest structural protein, with 1,255 amino acids, in the viral genome. Its structure can be divided into three regions: a long N-terminal region in the exterior, a characteristic transmembrane (TM) region, and a short C-terminus in the interior of a virion. We detected fifteen substitutions of nucleotides by comparisons with the seventeen published SARS-CoV genome sequences, eight (53.3%) of which are non-synonymous mutations leading to amino acid alternations with predicted physiochemical changes. The possible antigenic determinants of the S protein are predicted, and the result is confirmed by ELISA (enzyme-linked immunosorbent assay) with synthesized peptides. Another profound finding is that three disulfide bonds are defined at the C-terminus with the N-terminus of the E (envelope) protein, based on the typical sequence and positions, thus establishing the structural connection with these two important structural proteins, if confirmed. Phyloge-netic analysis reveals several conserved regions that might be potent drug targets. 展开更多
关键词 SARS CORONAVIRUS the S protein structure ANTIGENICITY
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Evolution and Variation of the SARS-CoV Genome
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作者 JianfeiHu JingWang +13 位作者 JingXu WeiLi YujunHan YanLi JiaJi JiaYe zhaoxu ZizhangZhang WeiWei SonggangLi JunWang JianWang JunYu HuanmingYang 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2003年第3期216-225,共10页
Knowledge of the evolution of pathogens is of great medical and biological significance to the prevention, diagnosis, and therapy of infectious diseases. In order to understand the origin and evolution of the SARS-CoV... Knowledge of the evolution of pathogens is of great medical and biological significance to the prevention, diagnosis, and therapy of infectious diseases. In order to understand the origin and evolution of the SARS-CoV (severe acute respiratory syndrome-associated coronavirus), we collected complete genome sequences of all viruses available in GenBank, and made comparative analyses with the SARS-CoV. Genomic signature analysis demonstrates that the coronaviruses all take the TGTT as their richest tetranucleotide except the SARS-CoV. A detailed analysis of the forty-two complete SARS-CoV genome sequences revealed the existence of two distinct genotypes, and showed that these isolates could be classified into four groups. Our manual analysis of the BLASTN results demonstrates that the HE (hemagglutinin-esterase) gene exists in the SARS-CoV, and many mutations made it unfamiliar to us. 展开更多
关键词 SARS SARS-COV motif frequency profile genomic signature Chaos Game Representation PUP
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