39 research outputs found

    BIOMECHANICAL CHARACTERISTICS OF HIP AND KNEE JOIN,T MUSCLE IN GRECO-ROMAN STYLE WRESTLERS

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    Strength is the basis to wrestlers to master wresting techniques and develop their skills. Strength training is one of the important factors in wrestlers training. With the development of new technique, studying method has changed a Ilot. We can combine muscle strength with motion analysis in studying strength training. By the Biomechanics analysis results reflected by the indexes, such as angle, angular velocity, isokinetic torque, etc, we can learn more characteristics of muscle working in sports, Based on these data, we evaluated ten Greco-Roman style wrestlers' 'lower limb strength and draw some conclusion about strength training

    Simulated Effects of Cropland Expansion on Summer Climate in Eastern China in the Last Three Centuries

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    To understand the effects of the land use/cover changes due to agricultural development on summer climate in Eastern China, four 12-year simulations using the WRF-SSiB model were performed. We found that agricultural development resulted in warming and rainy effects. In the middle to lower reaches of the Yellow River and the Yangtze River, the warming effects were approximately 0.6°C and resulted from increased surface net radiation and sensible heat fluxes. In Northeast China, the warming effects were very small due to increases in latent heat fluxes which resulted from the extensive conversion from grassland to cropland. The rainy effect resulted from increases in convective rainfall, which was associated with a warming surface in certain areas of the Yellow River and Yangtze River and a large increase in the surface moisture flux in Northeast China. Conversely, in the middle to lower reaches of the Yellow River and the Yangtze River, the grid-scale rainfall decreased because the climatological northward wind, which is moist and warm, was partially offset by a southward wind anomaly. These findings suggest that the agricultural development left footprints not only on the present climate but also on the historical climate changes before the industrial revolution

    Crop Yield and Temperature Changes in North China during 601–900 AD

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    Depending on the descriptions of crop yield and social response to crop failure/harvest from Chinese historical documents, we classified the crop yield of North China during 601–900 AD into six categories and quantified each category to be the crop yield grades. We found that the regional mean crop yield had a significant (P<0.01) negative trend at the rate of −0.24% per decade. The interannual, multiple-decadal, and century-scale variability accounted for ~47%, ~30%, and ~20% of the total variations of crop yield, respectively. The interannual variability was significantly (P<0.05) persistent across the entire period. The multiple-decadal variability was more dominant after 750 AD than that before 750 AD, while the century-scale variability was more dominant before 750 AD than that after 750 AD. The variations of crop yield could be partly explained by temperature changes. On one hand, the declining trend of crop yield cooccurred with the climate cooling trend from 601 to 900 AD; on the other hand, the crop yield was positively correlated with temperature changes at 30-year resolution with the correlation coefficient of 0.59 (P<0.1). These findings supported that high (low) crop yield occurred in the warming (cooling) climate

    Warming/cooling effects of cropland greenness changes during 1982-2006 in the North China Plain

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    This study analysed the changes in cropland greenness during 1982-2006 in the North China Plain (NCP) and investigated the warming/cooling effects of the greenness changes. The results show that while spring cropland greenness increased, early summer cropland greenness substantially decreased from 1982 to 2006. In contrast to the cooling and wetting effects of the greenness increase in spring, the greenness reduction in early summer had warming and drying effects. The cooling/warming effects of cropland greenness changes accounted for 47% of the spatial variance of daily maximum temperature (Tmax) change in spring and 44% in early summer. The wetting/drying effects of cropland greenness changes accounted for 48% of the spatial variance of daily minimum specific humidity (SPHmin) change in spring and 19% in early summer. The cooling-wetting/warming-drying effects mainly resulted from the distinct partitioning of surface net radiation between surface latent heat flux and sensible heat flux over cropland with different greenness. Canopy transpiration plays a dominant role. The increased (decreased) cropland greenness corresponds to high (low) transpiration rate, less (more) sensible heat flux and high (low) humidity, and consequently cooling-wetting (warming-drying) effects. In comparison, there was little change in surface net radiation, although surface albedo and emissivity had changed with greenness change. 2013 IOP Publishing Ltd

    Projecting the Potential Global Distribution of <i>Carpomya vesuviana</i> (Diptera: Tephritidae), Considering Climate Change and Irrigation Patterns

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    The ber fruit fly Carpomya vesuviana Costa (Diptera: Tephritidae) is the most destructive pests of Ziziphus spp. Carpomya vesuviana infestation causes great economic losses. We re-parameterized an existing CLIMEX model, and used the updated CliMond 30&#8242; gridded resolution datasets within CLIMEX for the periods 1987&#8211;2016 and 2071&#8211;2100, representing historical and future climates, respectively, to predict the potential global distribution of the pest. Under the historical climate scenario, C. vesuviana had a wide climatically suitable distribution worldwide, from approximately 46&#176; S to 50&#176; N. Future climate change expanded the upper boundary of the potential distribution northward, and predicted that the pest would distribute approximately from 50&#176; S to 60&#176; N. Temperature was the primary determinant of the potential distribution of the pest among all driving variables. Irrigation was associated with a slight improvement in the climate favorability for the pest in some areas, including south-western North America, northern and southern Africa, and most of Oceania. The projections clarify the impacts of climate change on the potential global distribution of C. vesuviana, and are instructive for quarantine and management agencies for reducing economic damage caused by the fly and preventing expansion of C. vesuviana due to climate change
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