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61.
The objective of this longitudinal study was to characterize growth and plasma insulin-like growth factor I (IGF-I) concentrations in pasture-raised thoroughbreds fed two sources of dietary energy. Mares and foals were randomly assigned to either a sugar and starch (SS) or fat and fibre (FF)-rich feed, and plasma IGF-I and growth were measured once a month from 1 to 16 months of age. These dependent variables were also compared with day length and ambient temperature. There was an association between plasma IGF-I concentration and average daily gain (ADG) (r = 0.32, p < 0.001). There were also clear seasonal patterns in both ADG and plasma IGF-I, with high values in June and May, and a low value in March. Plasma IGF-I and ADG were positively associated with day length and temperature. Plasma IGF-I was never higher (p > 0.10) in the FF group when compared with the SS group, and was higher in the SS group during a rapid growth phase in the spring of year 2 (p < 0.10). The results establish an association between ADG and IGF-I in the horse and indicate that environment and age may influence this relationship. In addition, plasma IGF-I is influenced by dietary energy source at particular times of year. This link has important implications in designing feeding management strategies that are aimed at addressing skeletal development.  相似文献   
62.
试验表明,三道湾水电站原设计存在以下问题:泄洪排沙洞单独全开运行工况下,其进口上方存在贯通性吸气漏斗漩涡;正常溢洪洞进口侧收缩十分严重,泄流量不足,闸后存在水翅、折冲波等不良流态,下游消能效果不佳;针对实际情况,试验通过在泄洪排沙洞进口增设消涡格栅,在正常溢洪洞进口设置椭圆形导墙、延长闸后收缩段,下游采用扩散挑流消能等措施,很好地解决了上述问题。  相似文献   
63.
多水门管道灌溉是采用多水口管道替代水沟的一种地表灌溉方式。1993至1995年试验结果表明,多水门管道灌溉和传统水沟灌溉相比,具有节水、节能、改善灌水分布均匀度,提高灌溉质量,缩短灌溉时间和扩大作物种植面积等优点  相似文献   
64.
随着全世界能源物质的不断扩展,可再生的生物质能源将是21世纪主要的能源物质。能源甜菜是新兴的可再生能源作物,它具有生物学产量高,乙醇转化率高,含糖量适中等特点,是取之不尽、用之不竭的环保能源,对环境几乎没有污染;同时又是糖饲兼收的作物。利用能源甜菜通过酒精发酵创造乙醇燃料新能源,可以减轻或消除与粮食争地的矛盾,是保证粮食安全和能源安全的双赢举措。  相似文献   
65.
66.
A theoretical model is developed for the dropwise condensation heat transfer on the horizontal circular surface with radial gradient surface energy based on the heat transfer model of individual condensate drop and the size distribution model of condensate drop on homogeneous condensation surface.The effect of variation of contact angle on the gradient surface on condensation heat transfer and condensate drop size distribution is taken account of in this model.The theoretical calculation method was obtained to predict the dropwise condensation heat transfer coefficient on the horizontal circular surface with radial gradient surface energy under various wall subcooled temperature,contact angle profile on wall surface,and working fluid.The effects of surface energy gradient,wall subcooled temperature,and thermophysical properties of condensate on the condensation heat transfer are discussed respectively.The calculation results show that the condensation heat transfer coefficient increases slightly with the increase of wall subcooled temperature.As latent heat and surface tension increasing,the condensation heat transfer coefficient increases.A larger surface energy gradient induces a larger condensation heat transfer coefficient.  相似文献   
67.
In this paper, the complex method of the nonlinear programming is used to optimize the parameters of energy dissipation bracing in energy dissipation braced frame. This method is realized with computer program and proved to be efficient. A 6-story reinforced concrete frame is used as a demonstrative example.  相似文献   
68.
In order to research the state of energy bands and gain and loss of electrons on the surface of ZnSnO_(3),it is put forward that Pinning theory of Fermi energy is applied to development of gas sensitive materials.The relative position between surface state and conduction band on surface of zinc tin complex oxide(ZnSnO_(3)) gas sensitive material has been investigated by utilizing oxidation redox couple,FeCl_(2)/ FeCl_(3),which have high surface state.Fermi energy is pinned at about 0.2 eV below conduction band E_(cs)on the surface of ZnSnO_(3).It has been determined that additives doping ratio,addition concentration and working atmosphere have no effect on this value.Therefore,pinning theory of Fermi energy has been verified by using this method.  相似文献   
69.
The concept of loss rate of available energy was introduced for evaluating heat exchanger performance. At the same time, the general expression of loss rate of available energy was obtained for heat exchangers of several typical. And NL criteria was recommended for evaluation of the loss rate of available energy of heat exchanger. Then. the influences of inlet temperatures ratio, heat capacity ratio of fluids, the number of heat transfer units and flow patterns of heat exchanger on ,VL criteria were also discussed.  相似文献   
70.
The mathematical relationship for assessing total energy consumption within a material life cycle is presented in this paper. According to the relationship,the procedure rationality of recycling waste may be assessed quantitatively.  相似文献   
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