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最大动量模糊极点训练爆发力的理论依据 被引量:2
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作者 杨红春 马继政 《南京体育学院学报(自然科学版)》 2002年第2期10-13,共4页
爆发力素质对几乎各种运动成绩的影响非常巨大,因而对其训练方法和理论的研究也就十分重要。本文拟从几个方面来阐述“最大动量训练法”的理论依据,同时对“模糊极点”训练方法进行介绍和概括,希望为运动训练实践提供参考。
关键词 最大动量 模糊极点 爆发力
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缓冲溢流阀卸荷阀口的优化设计与研究 被引量:4
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作者 彭利坤 宋飞 +1 位作者 陈佳 陈军奥 《海军工程大学学报》 CAS 北大核心 2017年第6期67-71,共5页
电磁溢流阀在卸荷时产生的压力冲击是由于对卸荷管路中油液动量变化控制不当引起的,为此提出了在卸荷全程都以初始卸荷时的油液最大动量变化量进行卸荷的设计思路,由此得出了缓冲阀阀芯开口宽度与阀芯位移间的对应关系,并据此对缓冲阀... 电磁溢流阀在卸荷时产生的压力冲击是由于对卸荷管路中油液动量变化控制不当引起的,为此提出了在卸荷全程都以初始卸荷时的油液最大动量变化量进行卸荷的设计思路,由此得出了缓冲阀阀芯开口宽度与阀芯位移间的对应关系,并据此对缓冲阀阀口进行了优化设计。然后,将新型的缓冲阀结构应用于电磁溢流阀卸荷回路组成了新型缓冲溢流阀,并通过试验研究了新型缓冲溢流阀对卸荷压力冲击的抑制效果,试验结果也验证了缓冲阀阀口优化设计的正确性和有效性。 展开更多
关键词 电磁溢流阀 压力冲击 最大动量变化量 缓冲阀 缓冲溢流阀
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提高篮球运动员弹跳力的研究 被引量:6
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作者 李卫平 陈雪梅 毕道远 《中国体育科技》 北大核心 1998年第9期29-30,共2页
本文运用“最大动量训练法”对12名男子篮球运动员进行了为期12个月的训练,结果发现此法能使运动员弹跳能力明显提高。
关键词 篮球运动员 最大动量 弹跳力
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提高高校排球运动员弹跳力的比较研究 被引量:3
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作者 刘立军 《哈尔滨体育学院学报》 2003年第2期112-114,共2页
通过对普通高校12名男子排球运动员随机分成两组,对其中的6名运动员定为实验组运用“最大动量训练法”进行了为期10个月的尝试性训练,另外对6名运动员定为对照组运用传统的弹路力的训练方法也进行了为期10个月的训练后,经过比较分析结... 通过对普通高校12名男子排球运动员随机分成两组,对其中的6名运动员定为实验组运用“最大动量训练法”进行了为期10个月的尝试性训练,另外对6名运动员定为对照组运用传统的弹路力的训练方法也进行了为期10个月的训练后,经过比较分析结果表现此法能使受训者弹路力明显经用传统的训练方法提高幅度加大。 展开更多
关键词 排球运动员 最大动量 弹跳力
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新型含能材料爆炸驱动能力数值模拟研究
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作者 刘天浩 孔德仁 +2 位作者 侯景华 姜旻昉 李东岳 《测试技术学报》 2021年第2期114-119,共6页
随着新型含能材料的不断深入研究,利用新型含能材料爆炸产生的强大能量进行驱动破片以达到更大的毁伤能力受到外界广泛关注.破片的飞行速度是评价破片毁伤威力大小的重要指标,故而对含能材料爆炸驱动破片的驱动能力评价和技术研究成为... 随着新型含能材料的不断深入研究,利用新型含能材料爆炸产生的强大能量进行驱动破片以达到更大的毁伤能力受到外界广泛关注.破片的飞行速度是评价破片毁伤威力大小的重要指标,故而对含能材料爆炸驱动破片的驱动能力评价和技术研究成为当前重要的研究课题.本文通过非线性动力学分析软件——AUTODYN软件对不同当量的3种含能材料TNT,HMX,HMX-TNT(1∶1)进行模拟数值仿真.建立了相应爆炸驱动装置仿真简化模型,设置TNT,HMX,HMX-TNT 3种含能材料当量分别为50 g,100 g,200 g时,对同一破片同一爆炸驱动装置进行爆炸驱动.仿真结果表明:不同爆炸驱动材料对于钨珠的驱动能力大小不同;本文利用破片最大速度和最大动量去表征含能材料的爆炸驱动能力大小,可以得出:同一质量情况下的爆炸驱动材料中,驱动能力大小依次为HMX>HMX-TNT>TNT,为破片驱动能力试验提供了数据支持和理论支持. 展开更多
关键词 新型含能材料 仿真模型 最大速度 最大动量 驱动能力表征
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高压容腔卸压曲线的研究
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作者 任晓剑 武晓凤 +1 位作者 姚平喜 张晓俊 《机床与液压》 北大核心 2013年第21期44-46,52,共4页
提出了使油液以无冲击、振动和气蚀的最大动量变化量排出高压容腔的卸压思想。通过理论分析与公式推导,得到了卸压过程中高压容腔压力、卸压阀开口面积、卸压时间三者之间的关系。基于负载敏感原理,对卸压阀阀芯结构进行了初步设计,分... 提出了使油液以无冲击、振动和气蚀的最大动量变化量排出高压容腔的卸压思想。通过理论分析与公式推导,得到了卸压过程中高压容腔压力、卸压阀开口面积、卸压时间三者之间的关系。基于负载敏感原理,对卸压阀阀芯结构进行了初步设计,分析表明:此阀口可满足快速、无冲击卸压的要求。 展开更多
关键词 高压容腔 卸压曲线 最大动量变化量 负载敏感
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投掷项目
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《体育科技文献通报》 1997年第7期35-36,共2页
G824.014.6 9702853使用最大动量训练法发展投掷运动员专项爆发力的尝试(HL,中,A]/刘北湘,石玉琴,白晋湘,高长渊//第八届全国运动生物力学学术会议.-1996年10月21-25日.-49-51(ZZY)投掷项目//专项力量//爆发力//动量//训练G824.119 9702... G824.014.6 9702853使用最大动量训练法发展投掷运动员专项爆发力的尝试(HL,中,A]/刘北湘,石玉琴,白晋湘,高长渊//第八届全国运动生物力学学术会议.-1996年10月21-25日.-49-51(ZZY)投掷项目//专项力量//爆发力//动量//训练G824.119 9702854超等长式俯卧撑练习对铅球技术的影响[刊.中,B]/杜刚//体育科学.-1997年3月.-17(2)-40(ZZY) 展开更多
关键词 投掷项目 运动生物力学 专项力量 超等长式俯卧撑 投掷运动员 铅球技术 训练法 最大动量 体育科学 学术会议
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Adsorption of Chlortetracycline from Water by Rectories 被引量:1
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作者 吕国诚 吴丽梅 +2 位作者 王晓龙 廖立兵 王小雨 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第5期1003-1007,共5页
The removal of antibiotics from water by clay minerals has become the focus of research due to their strong adsorptive ability. In this study, adsorption of chlortetracycline (CTC) onto rectories was conducted and the... The removal of antibiotics from water by clay minerals has become the focus of research due to their strong adsorptive ability. In this study, adsorption of chlortetracycline (CTC) onto rectories was conducted and the effects of time, concentration, temperature and pH were investigated. Experimental results showed that adsorption equilibrium was reached in 8 h. Based on the Langmuir model, the maximum adsorption capacity of CTC on rectories was 177.7 mg·g 1 at room temperature. By the study on adsorption dynamics, it is found that the kinetic date fit the pseudo-second-order model well. The adsorption of CTC by rectories is endothermic and the free energy is in the range of 10 to 30 kJ·mol 1 . The pH value of solution has significant effects on adsorption and the optimal pH is at acidity (pH 2-6). At concentration of 2500 mg·L 1 , the intercalated CTC produces an interlayer space with a height of 1.38 nm, which is 1.12 nm in raw rectories, suggesting that the adsorption occurs between layers of rectories. 展开更多
关键词 adsorptxon rectory CHLORTETRACYCLINE
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Submaximal oxygen uptake kinetics, functional mobility, and physical activity in older adults with heart failure and reduced ejection fraction 被引量:1
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作者 Scott L Hummel John Herald +5 位作者 Craig Alpert Kimberlee A Gretebeck Wendy S Champoux Donald R Dengel Peter V Vaitkevicius Neil B Alexander 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2016年第5期450-457,共8页
Background Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure (HF). We examined relationships between maximal o... Background Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure (HF). We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, fianctional mobility, and physical activity in older adults with HF and reduced ejection fraction. Methods Older adults with HF and reduced ejection fraction (n = 25, age 75 :i: 7 years) were compared to 25 healthy ageand gender-matched controls. Assessments included a maximal treadmill test for peak oxygen uptake (VO2p^ak), oxygen uptake kinetics at onset of and on recovery from a submaximal treadmill test, functional mobility testing [Get Up and Go (GUG), Comfortable Gait Speed (CGS), Unipedal Stance (US)], and self-reported physical activity (PA). Results Compared to controls, HF had worse performance on GUG, CGS, and US, greater delays in submaximal oxygen uptake kinetics, and lower PA. In controls, VO2peak was more strongly associated with functional mobility and PA than submaximal oxygen uptake kinetics. In HF patients, submaximal oxygen uptake kinetics were similarly associated with GUG and CGS as VO2peak, but weakly associated with PA. Conclusions Based on their mobility performance, older HF patients with reduced ejection fraction are at risk for adverse functional outcomes. In this population, submaximal oxygen uptake measures may be equivalent to VO2 peak in predicting functional mobility, and in addition to being more feasible, may provide better insight into how aerobic function relates to mobility in older adults with HF. 展开更多
关键词 AGING Congestive heart failure MOBILITY Oxygen uptake The elderly
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Engine-Out Takeoff Path Optimization for Large Civil Aircraft 被引量:4
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作者 Bertrand Masson Michael Bain John Page 《Journal of Mechanics Engineering and Automation》 2013年第6期352-361,共10页
Maximum regulated takeoff weights and hence payloads of large commercial jets are limited by government regulations which take into account local airport conditions as well as a variety of safety factors. One of the c... Maximum regulated takeoff weights and hence payloads of large commercial jets are limited by government regulations which take into account local airport conditions as well as a variety of safety factors. One of the challenging conditions that must be met is linked to a minimum obstacle clearance in the unlikely event of an engine failure on the runway at the worst possible time. This requirement becomes an overriding factor for airports surrounded by challenging terrain, and therefore a well defined takeoff path out of these airports has the potential to transform a financially unsustainable operation into a commercially viable one. The research described in this paper represents an ongoing attempt to resolve this important problem and makes use of recent advances in robot path planning techniques. 展开更多
关键词 TAKEOFF RNP (required navigation performance) large aircraft engine out procedure path planning.
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Salsa dance and Zumba fitness: Acute responses during community-based classes 被引量:1
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作者 Pablo A.Domene Hannah J.Moira +1 位作者 Elizabeth Pummell Chris Easton 《Journal of Sport and Health Science》 SCIE 2016年第2期190-196,共7页
Background: Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group... Background: Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group classes among the mainstream dance and fitness audiences; however, the efficacy of these activities for the purposes of health promotion currently remains unclear. The purpose of this study was to simultaneously assess the physiological responses and psychological experiences during salsa dance and Zumba fitness in a community sample of physically inactive women. Methods: Twenty-four participants, aged 22-56 years, visited the laboratory to perform a graded exercise test for determination of maximal oxygen uptake and maximal heart rate. The participants then attended 2 partnered salsa dance and 2 non-partnered Zumba fitness classes each in a counterbalanced order over a 2-week period. The 1-h classes were taught by certified instructors in established venues in the Royal Borough of Kingston and the surrounding communities of London, UK. Physiological data were collected using a wrist-worn ActiGraph wGT3X+ acceler- ometer with accompanying heart rate monitor and were processed using previously validated dance-specific techniques. Psychological experiences were measured via the Subjective Exercise Experiences Scale. Results: There was a significantly higher (p 〈 0.001) total time spent in moderate-to-vigorous physical activity (51.2± 3.1 vs. 32.6 ±5.9 min), total energy expenditure (411±66 vs. 210 ± 46 kcal), and total step count (6773 ± 556 vs. 4108 ±781 steps) during Zumba fitness when compared to salsa dance. Significant pre- to post-class improvements in positive well-being (p 〈 0.01, partial 7/2 = 0.4l) and psychological distress (p 〈 0.001, partial 02 = 0.72) were simultaneously observed for both salsa dance and Zumba fitness. Conclusion: The acute responses to classes of partnered Latin dance and non-partnered Latin-themed aerobic dance suggest that in physically inactive women participation is indeed efficacious in terms of community-based physical activity and psychosocial health promotion. 展开更多
关键词 ACCELEROMETRY AEROBICS Cultural dance EXERCISE Physical acti ~ity
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Generation of Entangled Multi-atom Dicke States in Cavity Quantum Electrodynamics
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作者 疏静 刘中 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1155-1159,共5页
We propose a scheme to generate two-atom maximally entangled state in cavity quantum electrodynamies (QED). The scheme can 5e extended to generation of entangled multi-atom Dicke states if we control the interaction... We propose a scheme to generate two-atom maximally entangled state in cavity quantum electrodynamies (QED). The scheme can 5e extended to generation of entangled multi-atom Dicke states if we control the interaction time of atoms with cavity modes. We use adiabatically state evolution under large atom-cavity detuning, so the scheme is insensitive to atomic spontaneous decay. The influence of cavity decay on fidelity and success probability is discussed. 展开更多
关键词 cavity QED Dicke states ENTANGLEMENT
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Aerodynamic Performance of Wind Microturbines and Their Dynamic Response
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作者 Gordon Breeze 《Journal of Civil Engineering and Architecture》 2016年第3期261-267,共7页
Wind microturbines typically have rotor diameters of 2 m or less. This paper presents theoretical expressions that can be used to determine the aerodynamic performance of wind microturbines. A commercially-available t... Wind microturbines typically have rotor diameters of 2 m or less. This paper presents theoretical expressions that can be used to determine the aerodynamic performance of wind microturbines. A commercially-available three-bladed microturbine was tested at the outlet plane of a wind tunnel. The cross-section dimensions of the wind tunnel jet are 2.5 m (horizontal) x 1.5 m (vertical). The tested microturbine has a diameter of 1.2 m, and it generates a maximum power output of about 300 W. The paper provides the wind tunnel test methodology that was used to determine the mean and fluctuating forces generated by the aforementioned wind microturbine. Both the static and dynamic responses of the turbine were measured, and results from this testing are presented in this paper. These results enable the trends and predictions of the theoretical expressions to be compared with wind tunnel measurements. It is shown that, for this particular microturbine, the behaviours of these test measurements are consistent with the expected theoretical predictions. 展开更多
关键词 MICROTURBINE WIND TUNNEL aerodynamic performance FORCES DYNAMICS
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3 m Twin-Segment Solid Rocket Engine Tested Successfully
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作者 YAO Tianyu 《Aerospace China》 2016年第3期63-63,共1页
On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aeros... On August 2,a twin-segment solid rocket motor of the largest diameter,grain mass and thrust in China completed its ground test firing with success.The3 m solid motor was independently developed by the Academy of Aerospace Solid Propulsion Technology(AASPT)under CASC. 展开更多
关键词 Rocket segmented technological completed rocket verified Segment firing thrust correctness
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试论正手上旋球 被引量:2
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作者 辛鹏章 《网球天地》 1997年第1期18-19,共2页
一、什么是正手上旋球 所谓正手上旋球,是指在握拍手的一侧,通过对球的向前向上的挥击,也就是向前击打,向上摩擦,即所谓“又打又摩、打摩结合”的技术击打使球围绕着横轴旋转向前飞行,并形成像彩虹样的弧线轨迹。这样球的飞行弧度很陡,... 一、什么是正手上旋球 所谓正手上旋球,是指在握拍手的一侧,通过对球的向前向上的挥击,也就是向前击打,向上摩擦,即所谓“又打又摩、打摩结合”的技术击打使球围绕着横轴旋转向前飞行,并形成像彩虹样的弧线轨迹。这样球的飞行弧度很陡,下降的速度极快,球落地后仍带有极强的上旋,因受向后作用力的关系,增加了向前的冲力,因而前冲力大并弹跳高,从而产生巨大的威力,这就是正手上旋球。 展开更多
关键词 上旋球 向前飞行 击球点 线轨迹 速运动 前冲力 东方式 协调性 后摆 最大动量
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