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41.
2015年的各位同学: 当你们打开你们的新概念电子信箱时,我──一个2001年的初一学生写给你们的这封信,也许能幸运地成为你们的“不速之客”。 首先恭贺你们可以坐在电脑前完成我们在学校才能完成的一切课程,用不着担心近视担心成绩担心开小差挨骂担心上课疲倦担心教室外心烦的噪音担心嘴的活动越轨……我们现在吵着闹着买电脑而你们却笑着忙着换电脑。可以这样说,你们所拥有的一切都是我们当今的梦想,社会的发展就是如此神奇,一次次把梦想变为现实,从而又产生新的 梦想…… 在你们接读此信 时,也许正是第一缕阳 光射进你们…  相似文献   
42.
假设有人给了你一枝笔,一枝密封的、纯色的水笔,里面有多少墨水你看不到,很可能刚刚试写几字便用干耗尽;也可能足以完成一部或几部杰作,永存于世,使世事为之大变。而这一切你在动笔之前却是一无所知。根据游戏的规则,你确实水远也不会知道,只能冒一下险。而事实上,也没有  相似文献   
43.
假如有人给你一支笔,一支密封的、纯色的水笔,里面有多少墨水你无法看到,很可能刚刚试着写几个字就能用干,也可能足够写一部或几部皇皇巨著,流传千古,使世事为之而改变。而这一切你在动笔之前无法知晓。  相似文献   
44.
In the present paper, a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading. The interaction between the blast wave and the concrete slab is considered in 3D simulation. In the first stage, the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab, then the results obtained from 2D calculation are remapped to a 3D model. The calculated blast load is compared with that obtained from TM5-1300. Numerical results of the concrete slab response are compared with the explosive test carried out-in the Weapons System Division, Defence Science and Technology Organisation, Department of Defence, Australia.  相似文献   
45.
中老年人由于骨刺形成或椎间盘狭小、椎间孔狭窄等颈椎病引起颈、肩、上肢疼痛、沉重、麻木、瘫痪 ,甚至头痛、眩晕、恶心呕吐等症状。笔者运用体、耳针配合近、远端取穴的针灸治疗方法 ,治疗 96例中老年颈椎病 ,取得满意疗效。现介绍如下 :一、临床资料本组 96例患者中 ,男性  相似文献   
46.
The purpose of this study was to explore the vulnerability for postpartum depression among financially, educationally, and socially advantaged middle-class women (n = 31). Twenty-nine percent reported prenatal depression, 13% reported intimate partner violence, and 22% reported concerns with partner relationships and support expectations after delivery. No illegal substances were reported; however, a past history of smoking and excessive use of caffeine was disclosed. Implications for practice focus on the need to screen and implement intervention programs for these social problems and to adopt measures as a universal standard of care for all women, regardless of demographic advantages.  相似文献   
47.
Do young boys and girls understand what leads to academic success (e.g., talent, effort, good teaching, luck) in the same way? Do young girls and boys have equivalent perceptions of their academic competence? Are these beliefs engendered in the same way across sociocultural contexts? In a cross-cultural study of over 3,000 children in grades 2 to 6, ages 7.2 to 13.6, we discovered that boys and girls around the world have very similar ideas about what generally leads to academic success. Moreover, in the few contexts where boys' and girls' academic performances were equal, their beliefs were also equal. However, when girls outperformed boys, their beliefs in their own talent were no greater than boys' beliefs, even though they did have stronger beliefs than boys in other facets of their achievement potential (e.g., putting forth effort, being lucky, getting their teacher's help). Our findings support the generally close correspondence between children's achievement and their competence-related beliefs, with the exception that young girls appear to specifically discount their talent. The effects held regardless of the children's achievement, intelligence, or age (approximately 8 to 13 years). Girls were more biased in some contexts than in others, however, suggesting that competence-related biases are rooted in culture-specific aspects of school settings.  相似文献   
48.
McQueen A  Getz JG  Bray JH 《Child development》2003,74(6):1737-1750
This longitudinal study examined how separation and family conflict mediated the effects of two acculturation variables (English language use and generational status) on substance use (alcohol, tobacco, and marijuana use) and deviant behavior outcomes in a Mexican American high school age sample. Structural equation modeling indicated that separation was a significant mediator of the relationship between acculturation and alcohol use, tobacco use, and deviant behavior. Family conflict mediated the effects of acculturation on marijuana use and deviant behavior. Model comparisons across gender groups suggested that generational status was an influential acculturation measure for females but not males. Additionally, English language use maintained a direct effect on marijuana use among females, whereas this relationship was mediated by separation for males.  相似文献   
49.
We investigated the kinds of instructional and assessment accommodations students with disabilities receive, and the extent to which instructional accommodations match assessment accommodations. Most students who had IEPs in specific content areas received instructional accommodations in those areas, and there were no differences by disability type. We provide data on the specific types of accommodations used. Overall, students' assessment accommodations matched their instructional accommodations, though many students received testing accommodations that had not been received in instruction. Implications are discussed for IEP teams who make decisions about instructional and assessment accommodations.  相似文献   
50.
原子核的秘密的揭露,使人类掌握了新的無穷尽的能源。第一座原子能电站在苏联的建立,为將这个能源实际利用于工業和农業的和平目的,奠定了基础。原子技术的發展,开辟了把放射性同位素应用到各种全然不同的科学技术部門中去的广闊的可能性。人工取得放射性同位素的方法之一,是在原子核反应堆中用中子来照射。比如,用中子照射普通的天然的磷的时候,部分的磷原子核就和中子結合而变成磷的放射性同位素(磷-32)的原子核。当放射性磷的核衰变的时候,核中的一个中子轉化成質子,同时放射出一个β粒子(帶陰电的电子)。衰变是按照这个方式發生  相似文献   
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