共查询到20条相似文献，搜索用时 500 毫秒
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利用作者最的导出的解析的ｂｃｃ结构的嵌入原子模型计算了由Ｖ、Ｎｂ、Ｔａ、Ｃｒ、Ｍｏ、Ｗ和Ｆｅ等７个ｂｃｃ结构元素组成的２１个合金系统的中间化合物Ａ、Ｂ、ＡＢ、ＡＢ３结构的形成焓，计算得到的形成的焓跟Ｗａｔｓｏｎ等人用经验能带得到地结果、Ｃｏｌｉｎｅｔ等人用集团方法得到的结果、Ｍｉｅｄｅｍａ等人用经验热力学理论得到的结果，以及已有的实验结果符合得比较好。 相似文献
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一、定义法例１ （１９９８年上海初二数学竞赛试题）在图（１）中 ,已知ＡＢ＝ＡＣ＝ＡＤ ,如果∠ＤＡＣ是∠ＣＡＢ的ｋ倍 ,那么∠ＤＢＣ是∠ＢＤＣ的（）倍．分析 :由ＡＢ＝ＡＣ＝ＡＤ ,联想到圆的定义 ,可知Ｂ ,Ｃ ,Ｄ三点都在以Ａ为圆心 ,ＡＢ长为半径的圆上（如图） ,借助圆周角与圆心角之间的关系 ,可使问题迎刃而解．显然 ,∠ＤＡＣ＝２∠ＤＢＣ ,∠ＣＡＢ＝２∠ＢＤＣ ,故选（Ａ）二、判别式法例３ 已知ａ,ｂ,ｃ是实数 ,且ｂ +ｃ＝８,ｂｃ＝ａ２ -１２ａ +５２ ,求ａ +２ｂ +３ｃ的值．解 :由ｂ +ｃ＝８得ｃ＝８ -ｂ,将其代入ｂ… 相似文献
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吴勤文 《中学数学教学参考》2001,(12)
在△ＡＢＣ中 ,重心Ｇ的等角共轭点Ｌ叫作类似重心[1] .本文导出△ＡＢＣ所在平面上的任意一点Ｐ到类似重心Ｌ的距离公式 ,从中可推出一些有意义的结果 .引理 1 [1] 设ＢＤ、ＣＥ为两条类似中线 ,ＡＣ =ｂ ,ＡＢ =ｃ,ＢＣ =ａ ,则ＡＤＤＣ=ｃ2ａ2 ,ＡＥＥＢ=ｂ2ａ2 .①引理 2 [2 ] 设Ｐ为△ＡＢＣ所在平面上任意一点 ,Ｄ、Ｅ分别是边ＡＣ、ＡＢ所在直线上的点 ,ＢＤ与ＣＥ交于Ｍ (Ｍ不在边上 ) .若 ＡＤＤＣ =λ ,ＡＥＥＢ=μ ,则ＰＭ2 =ＰＡ2 μＰＢ2 λＰＣ2λ μ 1 -λμａ2 λｂ2 μｃ2(λ μ 1 ) 2 .②定理 ＰＬ2 =… 相似文献
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三角形的一个有趣性质兰州石油学校王江云若用Ａ，Ｂ，Ｃ表示凸ＡＢＣ的三个内角，以ａ，ｂ。ｃ分别表示它们的对边（即ＢＣ＝ａ“ＣＡ＝ｂ，ＡＢ＝ｃ）则有以下定期。定理在ＡＢＣ中，若Ａ≥Ｂ，则即ｓｉｎａ＝ｓｉｎｂ＋ｓｉｎＢ，正弦定理，得推论１在ＡＢＣ中，若Ａ＞... 相似文献
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正弦定理和余弦定理是解斜三角形的两个常用定理．但是对于某些问题,若运用射影定理解决则更为方便．１定理与证明射影定理在△ＡＢＣ中,ａ、ｂ、ｃ分别是角Ａ、Ｂ、Ｃ的对边,则有ａ＝ｂｃｏｓＣ＋ｃｏｓＢ,ｂ＝ａｃｏｓＣ＋ｃｏｓＡ,ｃ＝ａｃｏｓＢ＋ｂｃｏｓＡ．图... 相似文献
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（３５）比例线段与平行线分线段成比例一、复习要点１．关于比例线段（１）在两条线段的比ａ∶ｂ中，ａ叫做比的项，ｂ叫做比的项．（２）在四条线段中，如果其中两条线段的比等于另外两条线段的比，那么这四条线段叫做线段．（３）如果ａ∶ｂ＝ｃ∶ｄ，那么、叫做比例外项，、叫做比例内项，ｄ叫做ａ、ｂ、ｃ的．（４）如果ａ∶ｂ＝ｂ∶ｃ，那么线段ｂ叫做线段ａ、ｃ的．（５）把线段ＡＢ分成两条线段ＡＣ和ＢＣ（ＡＣ＞ＢＣ）且使ＡＣ是ＡＢ和ＢＣ的比例项，叫做把线段ＡＢ黄金分割，点Ｃ叫做线段ＡＢ的点．２．比例的性质（１）基本性质… 相似文献
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Abilities and neural mechanisms underlying AB performance 总被引：3，自引：0，他引：3
A Diamond 《Child development》1988,59(2):523-527
Schacter, Moscovitch, Tulving, McLachlan, and Freedman propose that infants may make the AB error because of immaturity of the memory system damaged in amnesia (e.g., the hippocampus). They contrast this with the proposal that infants may make the AB error because of immaturity of the frontal lobe system (Diamond; Diamond & Goldman-Rakic). Schacter et al.'s choice of subjects, however, did not permit a test of these 2 proposals, and characteristics of their task, such as length of delay, make comparison with infants difficult. Schacter et al. discuss sensitivity to proactive interference as a possible explanation for the AB error, but sensitivity to PI is more closely associated with frontal lobe damage than with amnesia. Schacter et al. associate perseveration with immaturity or damage to the frontal lobe; it is suggested here that this is better characterized as lack of inhibitory control. Tasks that are most likely to require frontal cortex function are those that demand both short-term memory and inhibitory control. AB is an excellent example of such a task. 相似文献
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CARL E. THORESEN 《Counselor Education & Supervision》1977,16(4):296-303
Examining the validity of a theory scientifically requires careful attention to how one interprets data. Unfortunately the process is not clear-cut; the theoretical meaning of empirical data is not obvious. The experimental study by Avery et al. (1976) of empathic understanding (EU) is analyzed along with Horwitz's (1977) rejoinder. Generalizability theory and a multimethod strategy are recommended as ways to clarify reliability and data interpretation problems. 相似文献
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A new empirical correlation has been presented for the effect of entrainment on distillation tray efficiency based on the results of numerical solution given by Lockett,et al.The calculated results are in good agreement with those of the numerical solution given by Lockett,et al.The average deviation is 1.14% and the maximum deviation is 4.76% for the ranges of 0相似文献
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Fletcher, Savage, and Sharon (Educational Psychology Review, 2020) have raised a number of conceptual and empirical challenges to my claim that there is little or no evidence for systematic phonics (Bowers, Educational Psychology Review, 32, 681–705, 2020). But there are many mistakes, mischaracterizations, and omissions in the Fletcher et al. response that not only obscure the important similarities and differences in our views but also perpetuate common mischaracterizations of the evidence. In this response, I attempt to clarify a number of conceptual confusions, perhaps most importantly, the conflation of phonics with teaching GPCs. I do agree that children need to learn their GPCs, but that does not entail a commitment to systematic or any other form of phonics. With regard to the evidence, I respond to Fletcher et al.’s analysis of 12 meta-analyses and briefly review the reading outcomes in England following over a decade of legally mandated phonics. I detail why their response does not identify any flaws in my critique nor alter my conclusion that there is little or no support for the claim that phonics by itself or in a richer literacy curriculum is effective. We both agree that future research needs to explore how to combine various forms of instruction most effectively, including an earlier emphasis of morphological instruction, but we disagree that phonics must be part of the mix. I illustrate this by describing an alternative approach that rejects phonics, namely, Structured Word Inquiry.
相似文献15.
In two experiments, we examined two related conditioning problems previously investigated by Red-head and Pearce (1995a) and Pearce, Aydin, and Redhead (1997). Experiment 1 involved an A+, B+, C+, AB+, AC+, BC+, ABC2 discrimination. The Rescorla-Wagner model predicts that response to AB, AC, and BC will be greater than that to A, B, and C at asymptote, whereas the Pearce model makes the opposite prediction. In Experiment 2, we investigated the responding to a novel ABC compound in groups trained with either A+, B+, C+ or AB+, AC+, BC+. The Rescorla-Wagner model predicts greater response to ABC in the group trained with A+, B+, C+ than in the group trained with AB+, AC+, BC+, whereas the Pearce model makes the opposite prediction. In contrast to the findings of Redhead and Pearce (1995a) and Pearce et al. (1997) in pigeon autoshaping, our findings in rabbit eyelid conditioning support the Rescorla-Wagner model. 相似文献
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Research in mathematics education usually attempts to look into students’ learning and other mental processes. It could therefore
be expected to build on knowledge acquired within the academic discipline of cognitive psychology. Our aim in this paper is
to show how some recent developments in cognitive psychology can help interpret empirical results from mathematics education.
In particular, we will be looking into the heuristics-and-biases research by Kahneman and Tversky, the alternative views by
Gigerenzer et al., and the more recent dual-process theory that has come to play a central role in interpreting this research.
We first introduce the relevant background from cognitive psychology and survey its connections to previous work in mathematics
education; then we apply this theoretical framework for re-interpreting previously-published empirical data from mathematics
education research. We conclude with a discussion of potential theoretical and practical benefits of such synthesis. 相似文献
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《International Journal of Educational Research》2003,39(1-2):51-72
Research suggests potential problems when group work is used in school science to support the integrated acquisition of conceptual understanding and testing procedures. Yet integrated acquisition is promoted by current policy, and is a popular classroom strategy. Work by Howe et al. (Learning and Instruction 10 (2000) 361) indicates that the problems may be overcome if pupils: (a) discuss conceptual material in small groups and reach consensus; (b) subject consensual positions to guided empirical appraisal. The present paper reports a study with 9–12-year old pupils, which tests the proposal of Howe et al. using heat transfer as its topic, in contrast to the shadow size of Howe et al. In broad terms, the results are consistent with what Howe et al. report, although there are subtle differences in both outcome and process. Nevertheless, the similarities are such as to indicate a robust technique, with clear relevance to classroom practice. To facilitate application, the paper outlines what the technique requires in terms of group organisation and teacher support, and suggests that in both cases there is consistency with current practice. 相似文献
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Motivation predicts academic achievement beyond cognitive ability. Expectancy value theory (Eccles et al., 1983) is a widely accepted and powerful approach explaining academic achievement as well as educational choices and attainment. Recently, attention to the multiplicative term of expectancy and value beliefs has increased. Trautwein et al. (2012) reported a detrimental effect of high task value when expectancy beliefs were low. We aimed to replicate and extend their study by using a large, representative sample of students attending upper secondary school in the German federal state Schleswig-Holstein (N = 3367). Following Trautwein et al. (2012), we applied latent interaction modelling to test whether the predictive value of expectancy value interactions differs for grades, final examinations, and standardized test scores as measures of achievement in two domains. We took the multi-dimensional structure of task value into consideration, analyzing the four components (attainment, intrinsic value, utility and cost) separately. Both a verbal and a non-verbal domain (English as a foreign language and mathematics) were investigated. Overall, the results supported those of Trautwein et al. (2012). However, our findings suggested measure- and domain-specific differences when using expectancy value beliefs and their interactions to predict academic achievement. Interaction terms predicted final examination results in both English and mathematics. Further, interaction effects were significant for grades in English but not mathematics. In general, effect sizes of multiplicative terms were small, especially in contrast to expectancy beliefs. Findings are discussed regarding the practical and conceptual importance of the multiplicative term in expectancy value theory applied in an educational setting. 相似文献
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R Kail 《Child development》1988,59(4):1154-1157
In this article, I show that many of Stigler et al.'s criticisms of my 1986 article are incorrect or based on assumptions that are implausible. I agree with their conclusion, however, that theories of cognitive development must include both domain-specific and general processes. 相似文献
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李颖杰 《柳州职业技术学院学报》2014,(3):63-65
主要对《现代外语》2009年第3期上刊载的项成东教授的论文《英汉动物隐喻的跨文化研究》进行评述。通过分析,肯定了项成东从文化视角、体验哲学和认知机制分析动物隐喻产生差异的原因的研究方式及研究结论。同时,也指出了项成东论文存在的若干缺陷,并提出改进方法。 相似文献