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关键词： 教学方法   CAI课件   寄生虫检验   实验教学  

摘要： 多媒体计算机辅助课堂教学(简称CAI)给教育带来了新的革命.随着现代科技的发展,CAI在课堂教学中的运用会越来越广泛.掌握现代教育技术,并能正确、合理地运用到教学工作中去,是信息时代的要求,也是素质教育的要求.在有效时间内使学生既掌握理论,又能准确辨认各种寄生虫的形态结构,是寄生虫检验实验课堂教学所追求的目标.CAI课件是现代教育技术的应用软件,是以文字、图像、图形、声音、影像、动画等多种合成媒体为辅助工具的教学方式.在寄生虫检验实验教学中使用CAI课件,能创造人或事的导入,激发学生的学习兴趣,促进课堂教学内容、教学方法和教学过程的优化,教学效果明显提高.

关键词： outlier detection   molecular classification   DNA microarray   AIC   expression analysis  

摘要： Among samples analyzed for gene expression, samples incorrectly labeled or identified as likely contaminated are those whose expression patterns are markedly different. Such samples should be designated outliers, since they can exert a negative effect on the selection of informative genes for sample classification. We developed a method based on Akaike's Information Criterion (AIC) to detect such outliers. Our method is advantageous because it is free from a significance level and it facilitates objective decision-making. We applied our method to analyze the public microarray data of Alon et al. (1999) and found that some of the detected outlying samples coincided with samples considered as likely contaminated. Application of our method produced a higher discrimination level for informative genes in tumor- and normal tissues and, upon exclusion of the outliers, yielded higher classification accuracy. The detection of outlying samples prior to sample classification is essential, and the method described here serves as a valuable check.

关键词： Academic Achievement   Cognitive Development   Elementary Education   Learning Processes   Middle Schools   Science Activities   Science Instruction  

摘要： The current study examines the cognitive supports that underlie achievement in science by using a cultural historical framework (L. S. Vygotsky (1934/1986), Thought and Language, MIT Press, Cambridge, MA.) and the activity setting (AS) construct (R. G. Tharp & R. Gallimore (1988), Rousing minds to life: Teaching, learning and schooling in social context, Cambridge University Press, Cambridge, MA.) with its five features: personnel, motivations, scripts, task demands, and beliefs. Observations were made of the classrooms of seventh-grade science students, 32 of whom had participated in a prior achievement-related parent-child interaction or home study (P. R. Portes, M. F. Zady, & R. M. Dunham (1998), Journal of Genetic Psychology, 159, 163-178). The results of a quantitative analysis of classroom interaction showed two features of the AS: personnel and scripts. The qualitative field analysis generated four emergent phenomena related to the features of the AS that appeared to influence student opportunity for conceptual development. The emergent phenomenon were science activities, the building of learning, meaning in lessons, and the conflict over control. Lastly, the results of the two-part classroom study were compared to those of the home science AS of high and low achievers. Mismatches in the AS features in the science classroom may constrain the opportunity to learn. Educational implications are discussed. (C) 2002 Wiley Periodicals, Inc.

关键词： 包装学科   学科分类   分类体系  

摘要： 包装学科有其自身的特点和研究方法,现今的分类体系对包装学科的内部结构揭示不够充分。确定包装学科在分类体系中的地位,不仅是包装学科建设的需要,而且也是包装学科分类的重要依据。

关键词： 大鼠   小鼠   卵母细胞   有丝分裂   减数分裂   纺锤体检验点   MAD1   MAD2   Cytoplasmic dynein  

摘要： 有丝分裂或减数分裂是有丝分裂细胞周期或减数分裂细胞周期中的一个重要时相.有丝分裂纺锤体检验点作为有丝分裂正常运行的监控机制保证有丝分裂的高度忠实性,其监控的失常是非整倍体、遗传疾病和癌症的重要起因.对有丝分裂纺锤体检验点的了解已相当多,尽管很多机制还不很清晰.而相比之下,对减数分裂纺锤体检验点知之甚少.本研究以大鼠和小鼠卵母细胞为模型,研究在有丝分裂纺锤体检验点中起重要作用的MAD1、MAD2及马达蛋白Cytoplasmic dynein(胞质动力蛋白)在大鼠和小鼠卵母细胞的作用,从而丰富我们对减数分裂纺锤体检验点机制的了解并为哺乳动物卵母细胞非整整倍体的形成机制提供理论依据.

关键词： .size distribution   impactor   particulate matter   digested   Pt Pd   Vienna Austria   Pd and Rh   ICP-SFMS   urban aerosol   Viennese   open face   sampling head   determination of Pd   membrane desolvation   IDMS   external calibration   Pt and Rh  

摘要： Pt, Pd and Rh concentration levels related to particle size distribution were measured in Viennese aerosol. The urban aerosol was studied over a period of 1 month during summer 2002 in a heavy traffic area. A 6-stage cascade impactor collected classified particles with aerodynamic equivalent diameter (aed) v 10 mum. Total suspended particulate matter (aed v 30 mum) was assessed by filtering air (open face sampling head). The analysis of Pt, Pd and Rh in aerosol samples required a different strategy for each element to obtain accurate results and maximum sensitivity. Sample preparation was carried out by microwave-assisted acid digestion. For the determination of Pd an anion-exchange procedure was implemented. The digested samples were measured by ICP-SFMS in combination with ultrasonic nebulization and membrane desolvation, utilizing the high-resolution capabilities of this instrument for the determination of Rh. Pt and Pd were quantified by isotope dilution (IDMS), Rh by external calibration. Excellent detection limits of 0.07, 0.06 and 0.05 pg m(-3) (impactor substrates) and 0.18, 0.22, 0.14 pg m(-3) (open face sampling head substrates) for Pd, Pt and Rh, respectively, could be achieved. Since platinum group elements (PGE) are emitted from car catalysts as a result of mechanical processes, Pt, Pd and Rh were mainly found in the coarse fraction of urban aerosol. Summing up the concentrations assessed for the impactor stages (aed v 10 mum) revealed a weekly average of 4.3 +/- 1.7, 2.6 +/- 0.6 and 0.4 +/- 0.1 pg m(-3) for Pt, Pd and Rh respectively. Concentration levels of samples collected with the open face sampling head (aed v 30 mum) over the period of one week were significantly higher with average values of 38.1 +/- 6.3, 14.4 +/- 3.1 and 6.6 +/- 2.4 pg m(-3). Moreover, the presence of a collective of small particles containing the three investigated PGE was shown. Investigation of the impactor samples revealed an analogue size distribution for Pt, Rh and Pd wit

关键词： DSC   sample classification   statistical analysis  

摘要： The Similarity Match, Distance Match, Discriminant Analysis, Search Standards, and QC Compare Search techniques of statistical analysis are applied to DSC records in order to distinguish between two forms or classes of a new pharmaceutical active component. The classes are defined according to its therapeutic activity as 'positive' and 'negative'. Excellent results are obtained using the QC Compare Search Method.

关键词： 刮开式票据   印刷工艺   设备配置  

摘要： 一、刮开式税务票据的特点及要求 刮开式有奖发票采用了多种印制技术与计算机信息技术相结合的综合防伪技术,采用定额发票和机打式发票两种形式,增强了防伪性能,提高了发票印制的技术水平与科技含量,大大增加了伪造和虚开发票的难度,简化原发票的种类,增强了发票的通用性。由于采用了即开式兑奖方式,提高了消费者索取发票

关键词： 仪器分析用标准样品   校正样品  

摘要： 仪器分析用标准样品作为生产控制中的标准物、参照物使用。探讨了各类标准样品的名称、分类及使用要求 ,以使其使用规范化 ,避免使用不当而造成分析结果的可靠性降低

关键词： 二项选择模型   经济周期   货币政策   非对称性