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1.
ARTHUR R. JENSEN 《Journal of Educational Measurement》1974,11(1):1-14
An entire elementary school system with 60% white and 40% black pupils was given several abiity tests group-administered by 12 white and eight black examiners (Es). The tests measured verbal and nonverbal IQ, perceptual-motor cognitive development, “speed and persistence” under neutral and motivating instructions, listening-attention, and short-term rote memory for numbers. With the exception of the “speed and persistence” test, on which white Es yielded significantly and consistently higher mean scores than black Es for both white and black pupils across grades one to six, the results for the various cognitive ability tests showed that the race of the E did not produce large or consistent effects in the testing of white and black pupils. 相似文献
2.
Lorraine T. Dorfman 《Educational gerontology》2013,39(5):339-341
ABSTRACT The aging of college and university faculties mirrors general demographic trends in the United States (Administration on Aging, 2003). It also presents unique issues and challenges that reflect the work and retirement patterns of professors and the nature of academe itself (TIAA-CREF Institute, 2004). There have been major economic and policy changes of the past decade, including the uncapping or elimination of the mandatory retirement age for professors, the erosion of financial support for many public institutions of higher education, the use of more part-time and contract faculty, and the soaring costs of health care. These have all impacted college and university faculty and the institutions that they serve. This theme issue addresses the impact of some of those trends, and offers possible solutions to the complex issues that they raise. 相似文献
3.
Constructivism is a popular concept in contemporary teacher education programs. However, a genuine concern arises with the concept's application because many teachers and teacher educators claim that knowledge is constructed, without appreciating the epistemological and pedagogical implications such a claim entails. This article employs Phillips' (1995) analytic framework that divides the pedagogical applications of constructivism into three distinct categories: the good, the bad, and the ugly. Reviewing the constructivist epistemologies of Dewey and Vygotsky also enables the exploration of how constructivism might inform both our understanding of the impediments students confront when learning new knowledge and our understanding of general constructivist pedagogical practices. The primary objective in this article is to provide teacher educators and teachers with a richer understanding of constructivism—its limitations and its strengths—while offering concrete pedagogical strategies for its classroom application. 相似文献
4.
Contradictory findings characterize the literature on the efficacy of intergenerational programs that bring children and older persons together for joint activities to promote more positive attitudes and stereotypes. Nor is it clear whether cross-generational attitudes are negative to begin with. The research reported in this paper operationalized the constructs of attitudes and stereotypes by employing ideographic measures based on the attitude model of Fishbein and Ajzen (1975) and adopted the principles of the contact hypothesis in organizing a cross-age program. Sixty-three middle school adolescents (age 11–13) were randomly assigned to cross-age contact, didactic instruction, or control conditions for a 6-week program. Overall, adolescents and older persons held generally positive attitudes and stereotypes of each other. Relative to the control group, the contact group adolescents’ attitudes toward older people became more positive. There was no change in the didactic group. Following contact, the older people showed more positive attitudes toward younger people and scored higher on a measure of life satisfaction. 相似文献
5.
系统分析了辽中凹陷烃源岩的地球化学特征,并对烃源岩进行了综合评价,以期为辽中凹陷油气资源评价及战略选区提供科学依据。分析结果表明：沙一段有机质丰度为1.997%,有机质类型为Ⅱ1,具最高生产力,但因沉积厚度较薄,生烃量有限,不属于主力烃源岩;沙三段有机质丰度为1.64%,有机质类型以Ⅱ1为主,处于成熟—高成熟阶段;东三段有机质丰度为1.715%,有机质类型以Ⅱ1～Ⅱ2为主,处于成熟阶段。证实沙三段、东三段为辽中凹陷的优质烃源岩,目前没有大量发现优质烃源岩的原因是现在钻遇优质烃源岩的井不多或没有系统采样所致。 相似文献
6.
G.O. Coldevin 《Learning, Media and Technology》1979,5(3):70-76
This article presents an overview of broadcasting development and research in Tanzania, since coming to independence in 1961. Particular emphasis is given to the role of radio as a primary stimulus to the recent mass mobilization campaigns, and its support function in the on‐going national literacy project. The survey was undertaken from June, 1977, to July, 1978, during which time the author was visiting research professor at the University of Nairobi. One month was also spent in Dar Es Salaam during early 1978, interviewing relevant officials and researchers and assessing unpublished reports. The review incorporates published and unpublished material to mid‐1978. 相似文献
7.
本文针对不同的停时类型讨论了一类典型过程Ａ的对偶可料投影Ａ～之Ｅ｜Ａ～∞｜２的表现，并由此表现得到了它的估计，从而对［１］中相应结论给出了有意义的修正。 相似文献
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9.
在平面上,将形如（1－u）l1l2－ul0~2=0的二次曲线族中的l0~2换成l0~n,得到一类形如（1－u）l1l2－ul0~n=0的n次代数曲线,文章通过对此类曲线正则性、凸性的研究,给出了此类曲线在插值和逼进等方面的应用． 相似文献
10.
袁旭东 《广西师范大学学报(哲学社会科学版)》1990,(Z1)
若图G的每个子图H的连通度不超过2,则称图G是2可断图。对2连通2可断图的一些基本性质进行讨论,由此得到2连通2可断图的最大边数,并刻划了极值图的结构。 相似文献
11.
论基础教育阶段语文课的存在现状与存在范式 总被引：1，自引：1，他引：0
余昱 《广西师范大学学报(哲学社会科学版)》2005,41(3):97-100
作为基础教育阶段基础课之一的语文课,有其存在的独特价值,即书面文学语言系统的学习由语文课承担,学生情感思维能力的培养主要靠语文课完成,学生对祖国语言文字的热爱的感情主要在语文课上得到熏陶.语文课的存在范式为审美-情感范式.为更好理解这一范式,有必要厘清其与工具性、文学性、人文性的关系. 相似文献
12.
Xiao-fen He Jun-jun Wei Sheng-yun Shou Jian-qiao Fang Yong-liang Jiang 《Journal of Zhejiang University. Science. B》2017,18(3):239-248
Objective
To investigate the analgesic effects of electroacupuncture (EA) at 2 and 100 Hz on type 2 diabetic neuropathic pain (DNP) and on the expressions of the P2X3 receptor and calcitonin gene-related peptide (CGRP) in the dorsal root ganglion (DRG).Methods
Rat type 2 DNP was induced by a high calorie and high sugar diet fed for 7 weeks, plus a single intraperitoneal injection of streptozotocin (STZ) after 5 weeks. EA at 2 and 100 Hz was carried out once every day after 7 weeks for 7 consecutive days. Body weight, serum fasting insulin (FINS), fasting blood glucose (FBG), insulin sensitivity index (ISI), and paw withdrawal latency (PWL) were measured. The expressions of L4–L6 DRG P2X3 receptors and CGRP were assessed by immunofluorescence.Results
Type 2 DNP was successfully induced as shown by the increased body weight, FINS, and FBG, as well as the reduced ISI and PWL. Expressions of P2X3 receptors and CGRP in L4–L6 DRGs increased. EA at both 2 and 100 Hz relieved type 2 DNP, but the analgesic effect of EA was stronger at 2 Hz. P2X3 receptor expression decreased in L4–L6 DRGs following EA at 2 Hz and in L5 and L6 DRGs following EA at 100 Hz. EA at both 2 and 100 Hz down-regulated CGRP overexpression in L4–L6 DRGs.Conclusions
These findings indicate that EA at 2 Hz is a good option for the management of type 2 DNP. The EA effect may be related to its down-regulation of the overexpressions of the DRG P2X3 receptors and CGRP in this condition.13.
饶若峰 《黄冈师范学院学报》2003,23(3)
给出了半线性椭圆方程-Δu=λ1u+|u|2*-2u+τ(x,u)的Dirichlet问题在对扰动项τ(x,u)增加适当条件后非平凡解的存在性定理,以及方程-Δu=λu-|u|2*-2u+h(x),λ∈[λ1,λk](这里λk是方程-Δu=λu的第k个互不相等的特征值)的非零解的存在性定理. 相似文献
14.
张鹤 《辽宁师范大学学报(社会科学版)》2014,(5):639-643
中小企业是我国国民经济的重要组成部分,对推动科技创新、安置就业、提升城乡居民收入、带动城市经济发展起到重要作用。近年来,无论是中央政府还是地方政府都高度关注中小企业的发展,对中小企业的发展给予扶持和帮助,从而使中小企业成为城市经济新的增长力量。但是,中小企业在长期发展过程中,一直存在着创新能力不足,融资困难、应对外部环境变化经验不足等问题,这样使得中小企业发展困难重重,也在一定程度上制约了城市区域经济发展。因此,探讨大连中小企业发展的现状及主要存在的问题,明确未来发展方向,具有重要的现实意义。 相似文献
15.
Scholars like J.H. Van den Berg and P. Ariès 2 — not professional historians by origin — introduced a dramatic innovation in historical approaches. Influenced by their pioneering research on children in the past, many modern psychologists, sociologists or historians don't consider childhood (or youth, old age, maternal love...) as a natural, universal, ageless and self‐evident “phenomenon “ anymore. For F. Musgrove, for example, the concept of youth as a separate age of man is fairly recent. This sociologist expresses his opinion in a radical way: “The adolescent as a distinct species is the creation of modern social attitudes and institutions. A creature neither child nor adult, he is a comparatively recent socio‐psycho/ogi‐cal invention, scarcely two centuries old. [...] The adolescent was invented at the same time as the steam engine. The principal architect of the latter was Watt in 1765, of the former Rousseau in 1762”. 3 Such statements are a simplification of historical reality. The view of A. Kriekemans is more balanced: depending on the cultural environment, the term “youth “ may cover a different period of life and may be more or less complicated, involving varying levels of conflict, having its own identity, its own way of living, its own status, and its own expectations. 4 Let us apply these. words to Roman antiquity and examine the place of youth in the human life span as well as the circumstances which made possible its existence as a separate entity. Before starting the exposition itself, it should be noted that we are dealing with upper‐class youth (we know a/most nothing about youth in the lower classes) and with the young man (girls mostly married between the ages of 12 and 15 and there was no real interval between childhood and adulthood). 相似文献
16.
关于寿命分布NBU(2)类的若干封闭性质 总被引：1，自引：0，他引：1
康殿统 《上海大学学报(英文版)》2005,9(2):103-106
Some new results about the NBU(2) class of life distributions were obtained. Firstly, it was proved that the decrease with time of the increasing concave ordering of the excess lifetime in a renewal process leads to the NBU (2) property of the interarrival times. Secondly, the NBU(2) class of life distributions is proved to be closed under the formation of series systems. Finally, it was also shown that the NBU(2) class is closed under convolution operation. 相似文献
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18.
本文发现对Coats Redfern积分式进行适当修改后,可用于MnO_2与KClO_3催化反应的动力学研究,并找出了MnO_2与KClO_3催化反应中MnO_2的最佳用量。 相似文献
19.
Noting the wide differences in verbal abilities of middle and lower class children, the investigators proposed that two groups of children, one from the lower class, one from the middle class, who achieve comparable total scores on a group intelligence test, would get their scores by successfully completing different sets of items. In the first study children were placed in social classes based on their fathers' occupations, following guidelines from the Warner scale. Middle class children were matched with lower class children on total Otis scores. No item-social class interaction was found. The study was repeated using the occupational categories of the Dictionary of Occupational Titles as a guide to social class standing. Again no item-social class interaction appeared. If two social class groups are equated on total intelligence scores, one social class sample appears to succeed on essentially the same test items as does the other social class sample. A given score on an intelligence test appears to represent the same skills for one social class as it does for another social class. 相似文献
20.
This paper reports the asymmetric synthesis of an important pharmaceutical intermediate (3S)-1-[(1R)-2-hydroxy-1-phenylethyl]-3-methylpiperidin-2-one (compound 1) from commercially available D-plenylglycinol and delta-valerolactone. During the alkylation process, the hydroxyl group can be protected or unprotected, resulting in a different consumption of s-BuLi, and leading to a different diastereomeric excess (de) of compound 1. When 1-[(1R)-2-hydroxy-1-phenylethyl]-piperidin-2-one (compound 2) was alkylated with 2.5 eq. of s-BuLi, compound 1 was obtained as a single isomer detected by chiral high performance liquid chromatography (HPLC) columns with an overall yield of 91%. With the hydroxyl group protected, (R)-1-(2-[(tert-butyldimethylsil) oxy]-1-phenylethyl) piperidine-2-one (compound 6) could be alkylated with 1.5 eq. of s-BuLi, giving compound 1 and its diastereoisomer 8 in a ratio of 1:2.5 and a yield of methylation of 90%. Compounds 1 and 8 could be separated completely and easily by flash chromatography. The absolute configuration of compound 8 was determined by singlecrystal X-ray analysis. The mechanism of the alkylation process is discussed based on experimental results. 相似文献