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排序方式: 共有637条查询结果,搜索用时 31 毫秒
1.
采用RPE评分、运动成绩测试、心肺功能测试及心脏内分泌激素放射免疫法检测等方法对运动员心脏功能进行跟踪观察。结果表明:(1)穴位离子导入能明显改善运动员的主观感觉,提高专项成绩,改善心肺功能,降低无氧闲心率,提高有氧耐力,推迟心源性运动性疲劳的发生;(2)穴位离子导入可改善运动员心脏神经肽ET和CGRP的分泌,使之向更有利于适应运动负荷的方向发展。结论是:(1)心源性运动性疲劳的发生与多因素相关;(2)穴位离子导入能多环节、多层面地保护心肌和改善心脏功能,从而延缓疲劳产生和促进疲劳消除。 相似文献
2.
对滚动轴承疲劳故障产生的机理及疲劳破损过程进行了详细的分析,并提出了轴承最佳游隙的选择原则. 相似文献
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A multi-analytical approach for the study of brazilwood and its lake pigments was carried out based on historically accurate reconstructions. Recipes for brazilwood lakes from the fifteenth century technical text Livro de como se fazem as cores and the Winsor & Newton nineteenth century colourman's archive were reproduced and compared. Both primary sources allowed for the successful preparation of brazilwood lake pigments with colours that vary from light pink to dark red. The main steps and ingredients for the manufacture of these pigments were common in both sources, particularly the addition of Al3+ in the form of alum, and calcium carbonate (chalk). Reconstructions revealed that the latter acts as a pH buffer and filler, controlling the pH at which the lake pigment precipitates. The main difference between the two sources is that the nineteenth century recipes give the quantities for all ingredients, the precise temperatures and time, and achieved higher relative pigment yields (75% versus 45%). Full chemical characterisation of the reconstructions provided detailed information on the individual steps in the pigment manufacture and revealed that the presence of calcium sulphate dihydrate (gypsum) in the final pigment was a result of its formation in situ. Infrared, reflectance, and fluorescence spectroscopy proved to be essential and complementary techniques: while infrared was used to characterise additives and binders, reflectance and fluorescence data were fundamental for identifying the chromophore. The pigments and paints produced can now be used as standards for the identification and investigation of brazilwood lake pigments found in artworks. 相似文献
5.
Birgit Angelika Schmidt Martin Andreas Ziemann Simone Pentzien Toralf Gabsch Werner Koch Jörg Krüger 《文物保护研究》2016,61(2):113-122
A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified. 相似文献
6.
Jiří Baláš David Giles Jan Kodejška Michaela Panáčková Simon Fryer 《European Journal of Sport Science》2016,16(7):764-772
This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time–force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time–force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P?.05), force–time integral (↑ 28%, P?.05) and faster muscle re-oxygenation (↑ 32%, P?.05), when compared to the hand over hold condition. Further, the ratio of intermittent to continuous test time distinguished specific aerobic muscular adaptations among sport climbers (2.02), boulderers (1.74) and lower grade climbers (1.25). Lower grade climbers and boulderers produced shorter duration contractions due to the slower development of target force during the intermittent test, indicating worse kinaesthetic differentiation. Both the type of recovery and climbing discipline determined muscle re-oxygenation and intermittent performance in rock climbers. 相似文献
7.
刘文芝 《兰州石化职业技术学院学报》2002,2(3):42-43
为了解决目前比较流行的Uinx存在一些漏洞问题 ,提出了几种解决方法 ,结果安全有效。 相似文献
9.
陈大路 《温州职业技术学院学报》2003,3(4):29-31
本简要介绍了直线感应电动机的基本结构与工作原理,对直线感应电动机次级材料和厚度等对机械特性的影响作出分析,并对如何提高直线电机驱动移门机械特性提出措施和理论依据。 相似文献
10.
All the Americans cherish a beautiful myth in their hearts,which is called The American Dream.And in nowadays movies play a more and more important role in the American culture,as well as being a reflection of the American culture.The paper discussed this theme through explaining the four well-known American movies:The Great Gatsby,Foreest Gum,Born On The Fourth Of July And American Beauty. 相似文献