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本文通过对影响足球运动员有氧耐力的分析．指出影响足球运动员有氧耐力的生理因素主要有：①肺泡通气量及呼吸肌抗疫劳的能力;②红细胞的数量及机能稳定性;③心肌射血砭抗疲劳的能力;④运动肌肉的氧弥散和氧利用能力.在此基础上根据高原训练对足球运动员生理机能的影响,分析了高原训练对提高足球专项有氧耐力的利弊. 相似文献
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目的:研究运动员稀氧区域训练对肌肉纤维耐久力的影响。方法:分析18名运动员在常氧和高原低氧(模拟海拔4500 m递增负荷运动时,低氧通气反应速率、最大摄氧量以及最大耐力持续时间三个肌肉纤维耐久力评估指标的变化情况。结果:高原低氧训练时运动员低氧通气速率和最大耐力持续时间显著高于常氧对应值,高原低氧训练时,运动员最大摄氧量低于常氧对照组。高原低氧训练组,运动员在4个不同功率等级低氧通气速率,均高于常氧对应值,低氧通气速率在50%、75%以及100%最大功率时显著高于常氧对应值,最大摄氧量在各相对功率等级中,无显著性差异。运动员的低氧通气反应速率在高原低氧训练组至75%最大功率阶段降低,在75%至100%最大功率阶段基本保持平稳上升,不同相对强度下低氧训练组运动员最大摄氧量较常氧对应值显著降低。结论:高原运动训练下运动员肌肉纤维耐久力增强,疲劳时间降低,可提高运动员的运动能力。 相似文献
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目的:研究磷酸化活对高原缺氧负重训练动脉供血调控促进模型,促进运动员的心肺功能,提高运动员的供血调控水平。方法:通过高原缺氧负重训练,产生大量的磷酸化活物,人体中的磷酸化活物重组质粒p ET-28a-Agr C在C43(DE3)中表达为末端苏氨酸物体,通过提取人体内的血液标本,进行样本测试,对采集的运动员血液样本进行蛋白脂质体先用膜不可渗透硫醇-非荧光试剂(4-acetamido-4'-maleidylstibene-2,2'-disulphonic acid,Amdi S)标记,得到采用磷酸化活测定分析高原缺氧负重训练下的动脉供血调控促进模型结构。结果:运动员心率HR和肺活量VC显著性差异P0.01,缺氧负重训练中最大摄氧量VO2max的值都要大于台阶实验数值,达到最大摄氧量VO2max,心率HR的显著性差异P0.01。得到的测试组TG的心肺功能由于对比组CG1和CG2的显著差异性,进而促进动脉供血调控。结论:采用磷酸化活测定方法对高原缺氧负重训练动脉供血调控促进模型进行分析建模,对促进运动员的心肺功能,提高运动员的供血调控水平具有帮助。 相似文献
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通过对我国速滑项目近几年身体机能训练中有关田径跑这一身体机能训练手段进行比较研究,旨在于探讨田径各种跑对提高速滑项目运动员耐力水平作用机制。近几年,我国速滑应用跑的训练方法手段与过去相比有明减少趋势,跑的课次少,训练强度：血乳酸6mmol／L以下强度较多,高于10mmol/L以上强度少,冰期尤为突出。我国速滑长距离项目进步幅度不大,与发达国家差距没有缩小,在比赛中后程降速明显,身体耐力水平明显技不如人。耐力水平是制约因素中之主要因素,耐力水平的如何提高,身体机能训练是基础,田径跑是发展速滑运动员耐力水平重要手段,应加大在训练应用力度,促进速滑项目发展。 相似文献
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目的:探讨阶段运动负荷下调节纤维激酶,RPE与BP间的相关性。方法:以40名运动员为研究对象,采用自身对照法,动态调节纤维激酶,RPE与BP测量,观察运动员休息状态下到运动比赛后48h内的动态调节纤维激酶,RPE和BP变化。测定运动员运动结束后0 h,24 h,48 h的血液血清中总胆固醇(TC)与高密度脂蛋白胆固醇(HDL-C)的动态变化结果。结果:与散打运动前相比,一次运动后,运动员的BP都呈下降趋势,其中舒张压下降的程度更加明显。这种血压下降结果可持续10 h以上,24 h后恢复到运动前水平,运动后TC浓度下降(P0.05),HDL-C浓度上升(P0.05),BP与调节纤维激酶,RPE均无关,运动后24 h,HDL-C浓度持续升高(P0.01),BP受调节纤维激酶影响较大,48 h后,TC浓度恢复正常,HDL-C浓度保持较高,BP受RPE影响较大。结论:阶段运动负荷使人体血脂产生变化,运动对血脂的良好作用可持续48h,推荐3天进行一次运动,调节人体机能。 相似文献
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《科技通报》2015,(12)
目的:研究运动焦虑对运动员的相关生理指标影响分析,并进行数学模型构建,实现定量分析,准确分析运动焦虑对运动员身体健康指标的制约因素,并进行科学指导。方法:采用流式细胞方式对抗原体表面的CXCR3进行受体分析,得到不同组中的纤维细胞表面的RNA浓度为10 mol/L,取0.4 m L金磁微粒于离心管中磁性分离,弃上清,用0.5 m L的偶联缓冲液(20 mmol/L,p H7.4)清洗,引入运动焦虑的蛋白脂质体的自我磷酸化活性检测,评价蛋白脂质体的功能稳定性,实现运动焦虑对运动员相关生理指标影响建模分析。结果:训练中最大摄氧量VO2max的值都要大于台阶实验数值,达到最大摄氧量VO2max,DP,PP,MAP的显著性差异P0.05,运动状态下,使得人体血动脉的血红蛋白和脂质体共存于组分,促进人体耐运动焦虑的末端苏氨酸物体的生成。血蛋白和脂质体在组分3内的最大回收率分别为80%和90%。结论:运动焦虑对运动员的生理指标有较大影响,采用本文方法进行焦虑调节,促进运动员的耐力水平和身体机能,缓解运动焦虑症状,提高运动锻炼的积极性和有效性。 相似文献
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目的:观察不同运动方式对小鼠肝脏线粒体GSH-Px的影响,筛选出有效促进机体氧化抗氧化平衡的运动方式提供理论依据。方法:选用纯系雄性C57BL/6J小鼠32只作为研究对象,并随机分为四组,经过运动训练后,GSH-Px的活性;采用实时荧光定量PCR法检测肝脏线粒体中GSH-PxmRNA表达的变化。结果:耐力组GSH-Px mRNA的表达(P0.05);抗阻组(P0.01);耐力训练组与抗阻训练组比较(P0.05)。与对照组相比,耐力组同抗阻或混合组与抗阻组比较(P0.05)。结论:在三种运动方式中效果最为明显,因此肥胖人群可选择耐力训练作为减肥的运动方式。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献