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排序方式: 共有466条查询结果,搜索用时 15 毫秒
1.
运动性疲劳的细胞机制及研究进展   总被引:18,自引:0,他引:18  
运动性疲劳是一个十分复杂的过程,并受到多种因素的影响,迄今为止人们对其产生的机理仍未达成一致的看法。本文就运动性疲劳的机制问题对近几年来研究的热点及最新进展情况试作阐述。  相似文献   
2.
要培养和造就适应时代发展需要的创新人才,就必须更新教育观念,确立以创新为核心的教育思想,突破旧的教学模式,构建以培养人的创新精神和创新能力为基本价值取向的新的教育体系。本文结合《地基有基础》课程教学实践,探讨顺应时代发展需要、树立创新教育思想、实施创新教学、培养创新人才的做法。  相似文献   
3.
吸高氧对赛艇运动员大强度运动后血乳酸、酸碱度的影响   总被引:4,自引:0,他引:4  
胡永欣  肖国强 《体育学刊》2002,9(6):131-133
观察赛艇运动员运动后吸入高氧对乳酸(La)、碳酸氢根离子(HCO3^-)和pH值的影响,实验使用测功仪,在15min内划完4000m的运动负荷,测试吸氧量(VO2)、心率(HR)、血La、血pH值和HCO3^-浓度。结果表明,吸氧组与不吸氧组相比,吸氧组血La、pH值恢复得较快,并在运动后5、10min有显性差异;同样吸氧组HCO3^-恢复得较快,且在运动后20、30min有显性差异。结果提示,运动后吸氧可能改善体内酸性环境,加快乳酸的消除,有助于机体的恢复。  相似文献   
4.
Black-dyed artefacts are found in museums worldwide, many produced using an iron-tannate compound. Deterioration of iron-tannate dyed artefacts is an international preservation issue: in New Zealand the deterioration of paru (iron-tannate) dyed Māori textiles is widespread. This article reports experimental work testing the efficacy of sodium alginate, a consolidant developed for deteriorated paru-dyed muka (fibre from harakeke; Phormium tenax). The colour stability, strength retention, and acidity of paru-dyed muka consolidated with sodium alginate (0.25, 0.5, and 1% w/v in water) was tested pre- and post-artificial light ageing. This study found that sodium alginate had no negative effect on paru-dyed muka and in some cases provided benefit. Interestingly, the colour of paru-dyed muka is substantially more stable in UV-filtered light than previously recognised. Also microfading results were in agreement with visual assessments of colour change at 1 Mlux hour exposure, providing confidence in this relatively new technique to assess colour change.  相似文献   
5.
This paper examines the effect of modifiers on the stability of a vinyl acetate/ethylene copolymer dispersion adhesive upon aging. Eighteen common modifiers were added to a well-characterized vinyl acetate/ethylene copolymer dispersion (Dur-O-Set® E-150) in known concentrations and dry-film samples were subjected to 16–17 years of dark aging and seven to eight years of light aging. Yellowing, pH, gloss, swelling, cohesive strength, and flexibility were monitored for changes upon aging. Generally, the neat Dur-O-Set® E-150 (no additives) was found to become acidic on aging, but was fairly resistant to yellowing. It also swelled substantially in toluene, was of high gloss, medium strength, and flexible, and remained so on aging. No modifier was found to improve these properties. Various solvents, wetting agents, and thickeners did not alter the properties by much, while plasticizers, freeze-thaw stabilizer, glycerin, and certain fillers had a more negative effect.  相似文献   
6.
针对高职教育特点及教学现状,就《土力学与地基基础》课程,在教学内容、教学方法、实践环节及考核方式等方面进行了一系列的改革探索,谈了一些具体做法和设想,具有一定的实用性和可操作性。  相似文献   
7.
湘中衡阳盆地紫色土丘陵岗地分布广泛,这里普遍植被稀疏,水土流失严重,部分地区甚至基岩裸露,土地荒芜,呈现红色荒漠化现象。本文以衡南县工联村为例,针对湘中紫色土丘岗区综合开发项目示范区的农业生态工程优化模式,采用层次分析法和对比分析法,分别从生态效益、经济效益、社会效益和综合效益等方面进行1990年与2001年的对比分析。结果显示,工联村农业生态经济系统的生态效益、经济效益和社会效益指数均有显著提高,并已由非生态农业阶段发展进入到良性生态农业阶段,为湘中紫色土丘陵综合治理、农业生态工程建设和农业结构调整提供了一个良好的示范。  相似文献   
8.
工程教育认证制度是国际通行的质量保证办法,是工程师制度改革的基础,是未来工程师能力水平的保证。IEET推动的工程教育认证是一项非政府的审查机制,主旨为“以学生学习成果为导向(outcome-based),确保专业的教育品质”。那么结合现代信息化教学技术——微课的理念,本文主要探索土力学实验教学新模式,设计出符合创新人才培养目标要求的土力学实验课程教学内容,期待能为高等学校相关专业土力学实验课程任课教师准备实验教学内容提供参考,同时也为同行开展相关实验及学生设计创新实验提供借鉴。  相似文献   
9.
Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6~84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P<0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P<0.01). (3) Soil iodine value was 0.11~2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.  相似文献   
10.
Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.  相似文献   
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