排序方式： 共有49条查询结果，搜索用时 15 毫秒
41.
Zahra Gooya 《Educational Studies in Mathematics》2007,65(3):331-347
The geometry textbooks of the new system of secondary education in Iran differed dramatically from the old ones considering
the aims, the visions, the content, the approach, and the educational purposes. Four hundred eighty mathematics teachers participated
in a nationwide professional development program conducted by the author to facilitate the implementation of the new changes.
Based on this program, a research study was designed to investigate the teachers’ beliefs about a new reform in high school
geometry as a result of the professional development program. The data of the study were collected through teachers’ reflective
writings, project works, group discussions, reflective questionnaires, and oral communications. The purpose of this paper
is to draw upon this study and to document mathematics teachers’ beliefs about new changes. 相似文献
42.
Zahra Saffari Maryam Farahnak Zarabi Hasan Aryapour Alireza Foroumadi Ali Farhangi Soheil Ghassemi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2015,30(2):140-149
Chemotherapy drugs, used for prevention of uncontrolled cell proliferation in certain tissues as well as inducing apoptosis in tumor cells, are important candidates for treatment of cancer. The synthesized 2-amino-4H-chromene-3-carbonitrile derivatives effective on cancerous cells resistant to other drugs such as Paclitaxel were used due to their ability in induction of apoptosis. The growth inhibitory and inducing apoptosis activities were determined. In order to make it target-oriented, the best compound was conjugated with gold nanoparticles (NPs) by aspartic acid with chemical reduction method. Cytotoxicity effect of 2-amino-4H-chromene-3-carbonitrile derivatives against the T47D breast cancer cell line was determined by MTT assay. The synthesis of gold NPs was confirmed by transmission electron microscopy, UV–Vis and dynamic light scattering. To assess the effects of compounds on the process of apoptosis, staining methods with acridine orange–ethidium bromide and Hoechst staining by fluorescence microscopy and DNA fragmentation by the diphenylamine method were used. The synthesized compounds containing two NH2 groups on benzene rings, demonstrated more cytotoxicity effect. The effect of conjugation with gold NPs and the induction of apoptosis were studied with the best compound. The cytotoxicity effects of the synthesized 2-amino-4H-chromene-3-carbonitrile compounds were changed by replacement of NO2 group on thiol ring with different chemical groups on the benzene ring. Analyses of treated cell lines by conjugated and non-conjugated forms of compounds verified their ability in inducing apoptosis while conjugated form demonstrated higher apoptosis. 相似文献
43.
Jennifer D. Cribbs Zahra Hazari Gerhard Sonnert Philip M. Sadler 《Child development》2015,86(4):1048-1062
This article empirically tests a previously developed theoretical framework for mathematics identity based on students’ beliefs. The study employs data from more than 9,000 college calculus students across the United States to build a robust structural equation model. While it is generally thought that students’ beliefs about their own competence in mathematics directly impact their identity as a “math person,” findings indicate that students’ self‐perceptions related to competence and performance have an indirect effect on their mathematics identity, primarily by association with students’ interest and external recognition in mathematics. Thus, the model indicates that students’ competence and performance beliefs are not sufficient for their mathematics identity development, and it highlights the roles of interest and recognition. 相似文献
44.
Little empirical research has compared the manufacturing strategies of corporate and independent new ventures. This study explores these differences with data from the young, science-based biotechnology industry, and examines the performance effects of manufacturing strategy variables including scope, competitive thrust, and capabilities. The results show that the corporate and independent biotechnology new ventures pursue significantly different manufacturing strategies, and that different dimensions of manufacturing strategies affect the performance of corporate vs. independent ventures quite differently. 相似文献
45.
Tess Allegra Forest Zahra Abolghasem Amy S. Finn Margaret L. Schlichting 《Child development》2023,94(5):e279-e295
Trajectories of cognitive and neural development suggest that, despite early emergence, the ability to extract environmental patterns changes across childhood. Here, 5- to 9-year-olds and adults (N = 211, 110 females, in a large Canadian city) completed a memory test assessing what they remembered after watching a stream of shape triplets: the particular sequence in which the shapes occurred and/or their group-level structure. After accounting for developmental improvements in overall memory, all ages remembered specific transitions, while memory for group membership was only observed in older children and adults (age by test-type interaction η2 = .05). Thus, while young children form memories for specifics of structured experience, memory for derived associations is refined later—underscoring that adults and young children form different memories despite identical experience. 相似文献
46.
Nazim HUSSAIN Hui LI Yu-xiao JIANG Zahra JABEEN Imran Haider SHAMSI Essa ALI Li-xi JIANG 《Journal of Zhejiang University. Science. B》2014,(2)
研究目的:生育酚是菜籽重要的品质指标,氮肥是影响作物生物学与籽粒产量最常用的肥料。这项研究旨在搞清楚氮肥种类与施量对油菜种子生育酚含量与组分的确切影响,以及这种影响在基因型之间的差异。创新要点:这篇论文研究了不同的氮肥种类(硝态氮与铵态氮)与低、中、高施用量对种子生育酚总量与组分的影响,并分析了其中的原因,为通过合理的氮肥施用方案配置,以达到最理想的菜籽生育酚含量或组分提供依据。研究方法:采用盆钵实验控制氮肥施量与流失的精准方法,五种基因型、二种氮肥种类、三档施量水平,三重复控制误差;尝试用气相色谱法检测菜籽生育酚含量的新方法。重要结论:尿素比硝酸氨更有利于菜籽总生育酚、阿尔法生育酚及伽马生育酚的有效形成;提高氮肥施量对于菜籽形成高含量的总生育酚与伽马生育酚非常有效,但对提高菜籽阿尔法生育酚含量的效果却不太明显。 相似文献
47.
Rahim Esfandyarpour Mehdi Javanmard Zahra Koochak Hesaam Esfandyarpour James S. Harris Ronald W. Davis 《Biomicrofluidics》2013,7(4)
Detection of proteins and nucleic acids is dominantly performed using optical fluorescence based techniques, which are more costly and timely than electrical detection due to the need for expensive and bulky optical equipment and the process of fluorescent tagging. In this paper, we discuss our study of the electrical properties of nucleic acids and proteins at the nanoscale using a nanoelectronic probe we have developed, which we refer to as the Nanoneedle biosensor. The nanoneedle consists of four thin film layers: a conductive layer at the bottom acting as an electrode, an oxide layer on top, and another conductive layer on top of that, with a protective oxide above. The presence of proteins and nucleic acids near the tip results in a decrease in impedance across the sensing electrodes. There are three basic mechanisms behind the electrical response of DNA and protein molecules in solution under an applied alternating electrical field. The first change stems from modulation of the relative permittivity at the interface. The second mechanism is the formation and relaxation of the induced dipole moment. The third mechanism is the tunneling of electrons through the biomolecules. The results presented in this paper can be extended to develop low cost point-of-care diagnostic assays for the clinical setting. 相似文献
48.
Zahra Zamani 《Journal of Adventure Education & Outdoor Learning》2016,16(2):172-189
Outdoor preschools are critical for children’s play and development. Integrating observational and interview methods, this study examined four-to-five-year-old children’s cognitive play experiences in an outdoor preschool with natural, mixed and manufactured zones. The observational results indicated that the natural and mixed zones offered a diverse spectrum of cognitive play, were supportive of different learning styles and expanded their understanding about the world. Children preferred the diverse, challenging and constantly evolving natural settings in these zones. Integrating diverse natural and manufactured settings with loose elements, the mixed zone supported considerable opportunities for functional, exploratory and games with rules play behaviors. The accessible loose materials inspired children’s imagination, social engagement and games. In contrast, the manufactured zone offered the most functional and non-play behaviors, and was perceived as an unexciting, predictable and tedious environment. The findings suggest incorporating natural features and settings in outdoor preschools to support a diverse spectrum of cognitive play. 相似文献
49.