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本文指出了中重度弱智儿童学习实用性词汇的重要性，介绍了图形提示消退教学法的概念及其作用，阐述了在中重度弱智儿童阅读教学中采用此法的优越性，以及教学材料的准备方式、方法、原则及实施此法的基本步骤。这有利于临床工作者借鉴。 相似文献
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《文物保护研究》2013,58(4):308-313
AbstractThe oak timbers of the Swedish warship Vasa are deteriorating. High amounts of oxalic acid have been found along with a low pH and low molecular weight cellulose deep in the wood timbers. The iron-rich surface wood differs from the interior wood in that it displays higher pH and cellulose with higher molecular weight. The objective of this study was to determine why there is a difference in cellulose degradation, pH, and oxalic acid amount between the surface region and the interior of the Vasa timbers. Analysis of cellulose weight average molecular weight by size exclusion chromatography was performed, as well as quantification of oxalic acid and iron by high-performance anion exchange chromatography and atomic emission spectroscopy, respectively. It was found that a decrease in iron content coincides with an increase in oxalic acid concentration and a drop in pH at a certain depth from the wood surface. When iron-rich surface wood samples from the Vasa were mixed with an aqueous solution of oxalic acid, a fast increase of pH over time was observed. Neither interior wood poor in iron nor the fresh oak reference showed the same neutralizing effect during the time of measurement. This indicates that the presence of iron (rust) causes a neutralization of the wood, through the formation of iron(III) oxalato complexes, thus protecting the wood from oxalic acid hydrolysis. This effect was not observed to the same extent for other acids observed in Vasa wood (sulfuric, formic, glycolic, and acetic acids). 相似文献
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When dealing with contemporary art, conservators have to address not only the material aspects of the artwork but also other highly complex issues. The Argentinian artist Leon Ferrari is a representative example. He created avant-garde art installations but also worked with traditional techniques. His works raise dilemmas over concepts such as authorship, authenticity, legitimacy of art. Some of his artworks only interested him as a means to express his opinions and he was not concerned about alterations in their appearance. Therefore, what should be kept in them is not in an area of certainty for conservators. An essential key for achieving a responsible and respectful conservation result, is to understand the ideology involved in each ‘art piece’ created by Ferrari. 相似文献
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微生物降解有机磷农药的研究进展 总被引：1，自引：0，他引：1
果蔬菜等农产品有机磷农药残留越来越严重,利用微生物降解有机磷农药,在改善环境和人们生活质量方面已显得经济而有效。本文就降解有机磷农药的微生物种类,降解机制及编码降解酶的相应基因,以及工程菌的构建作了综述。 相似文献
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张凡 《首都体育学院学报》2003,15(3):101-103
FDP在临床中有许多积极作用，其表现为：FDP可作为高能底物和代谢调节物代偿ATP生成；增强组织细胞抗氧化能力，增加红细胞数量，及调节代谢紊乱；提高无氧、有氧运动能力，有利于疲劳的恢复。 相似文献
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目的通过给大鼠注射AMPK激动剂AICAR,提高大鼠骨骼肌中AMPK的活性,观察FoxO3 mRNA表达量的变化,探讨骨骼肌蛋白质的降解机制。方法 24只雄性SD大鼠,8月龄,180～200 g,根据用药后的取材时间分4组:AICAR注射后1 h组、2 h组、7 h组,生理盐水对照组。采用同位素技术测定腓肠肌中AMPK活性变化,采用荧光定量PCR技术,测定腓肠肌中MuRF1、MAFbx、FoxO3基因表达量的变化。结果 AICAR注射后1 h组、2 h组、7 h组,AMPK活性与对照组相比显著性升高(P<0.05或P<0.01),AICAR注射后7 h组,AMPK活性开始下降;AICAR注射后1 h组、2 h组,MAFbx mRNA、MuRF1mRNA表达量与对照组相比非常显著性升高(P<0.01),分别升高2.45、2.23倍和2.67、2.30倍;AICAR注射后7 h组,MuRF1 mRNA表达量显著性升高(P<0.05),升高2.01倍;FoxO3mRNA表达量在AICAR注药组与对照组之间没有显著差异。结论 研究认为大鼠一次性注射AICAR,提高AMPK活性,可能不是通过促进FoxO3 mRNA的表达,促进骨骼肌蛋白质的降解。 相似文献
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LAS降解菌分离、驯化及降解能力的研究 总被引：1，自引：0，他引：1
通过实验,从长期被洗涤涤剂污染的土壤中获得了对十二烷基苯磺酸钠(LAS)降解能力较强的细菌,在一定条件下测定了该菌种的生长情况及对LAS的降解能力.24小时内,菌体生长很快,40mg/ l的LAS的菌悬液的吸光度 (OD值) 达0.781,240mg/ l的OD 值为0.509. 在48小时内, 40mg/ l的 LAS 的去除率为 59.41%,高浓度的LAS(240mg/ l)的去除率为31.63%;240小时内,40mg/ l的LAS去除率为85.71%,240mg/ l的LAS去除率为 38.76%. 相似文献
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南水北调东线工程沿线湖沼湿地生态环境特征及退化分析 总被引：6，自引：1，他引：6
南水北调东线工程沿线湖沼湿地广泛发育,以浅积水的内陆淡水湿地为主.天然湖泊湿地向人工、半人工湿地演变明显,沼泽湿地均属于富营养型.湿地生物资源较为丰富,种群结构具有趋同性.由于自然与人为过程相互作用的结果,湖沼湿地的生态环境呈现了明显的退化趋势:湿地水量减少,面积逐渐萎缩;湿地水体普遍受到污染,污染程度从南向北加剧;湖泊湿地水体普遍处于中、富营养化状态;生物资源呈现衰减趋势;湿地调蓄功能逐渐下降.文中对湖沼湿地退化的形成原因、机制进行了分析,认为自然过程是退化的前提、基础,人为过程是退化的主要驱动力.本文为进一步研究东线工程对湖沼湿地生态环境的影响提供了基础. 相似文献
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放牧压力下五台山高山、亚高山草甸的退化特征 总被引：5，自引：0，他引：5
放牧通过家畜的啃食、践踏、排泄干扰草甸环境,使草甸的物种组成发生改变,植物种群的优势地位发生更替。在样带和样地调查基础上,获取草地群落组成和样地环境数据,通过CCA排序对五台山高、亚高山草甸在经历放牧后的退化状况进行数量化评价,辨识草甸退化的不同等级。结果表明：共划分出5个退化等级,随着退化加剧：①群落环境因子牛马粪数量增加、土壤紧实度加大,土层厚度降低。极度退化草甸与其他4个退化等级之间的环境因子差异显著;②群落数量特征总盖度、生物量、物种丰富度、多样性指数降低,同时一二年生植物所占百分比升高;③放牧干扰草甸的优势种是嵩草、高原嵩草和直梗高山唐松草,轻度干扰草甸中嵩草、高原嵩草(亚高山草甸)/珠芽蓼、高山嵩草、发草(高山草甸)为优势种,中度退化草甸高原嵩草依然为优势种,重度和极度干扰草甸中优势种被鹅绒委陵菜和平车前取代。放牧已对五台山高山、亚高山草甸群落外貌造成了严重的不良影响,是草甸退化的重要影响因素。为防止草甸资源进一步退化,促进草甸植被恢复,实现资源的可持续利用,建议对中度退化以上草甸采取严格限制家畜数量、分期围封和人工建植乡土植被等措施。 相似文献