带锯条安全容许高张紧力计算法的研讨

本文根据锯条不对称弯曲(或脉动)循环交变应力的持久极限,提出带锯条安全容许的高张紧力公式,并与日本木材工业手册(1982)的张紧力计算式和瑞典Kockums集团公司的高张紧力上限线作了对比。分析研究证明,作用于带锯条并转化成等效脉动循环容许的最大变应力大约为250N/mm~2。要提高张紧应力,必须使用较薄的锯条,以降低弯曲应力来补偿张紧应力的提高,保持总应力状态大致不变。     

Effect of Age and Performance on Physical,Hematological, and Biochemical Parameters in Endurance Horses

Endurance horses are subjected to heightened stress even after several conditioning protocols. Hence, the goal of this study was to examine the effect of age and performance on the hematology, biochemistry, and physical parameters after an endurance race. Eighteen horses aged 6-15 years were grouped into 80-km race category. All the horses were physically examined, and blood samples were collected postrace. After physical examination, the poor (n = 9) and good (n = 9) performance horses were identified. Potassium concentration was significantly higher (P < .05) in the good performance horses; chloride concentration was significantly higher (P < .05) in the poor performance horses. The mean blood glucose concentration of the poor performance horses in all the age-groups was significantly higher (P < .05). The mean blood lactate concentration was significantly lower (P < .05) in the poor performance horses. There was significant effect of performance on heart rate (P < .031), capillary refill time (P < .013), and gut motility (P < .05). Univariate Fisher exact test results were significantly higher for skin recoil (P < .03), mucous membrane (P < .03), and gait (P < .04) in the performance categories. In conclusion, the influence of age was seen in the poor performance category in relation to lactate, but age did not influence other physical, hematological, and biochemical parameters of the endurance horses. Thus, further studies are required to determine whether physical, hematological, and biochemical parameters during training could be used to estimate performance in endurance horses based on age.     

Contribution to our knowledge of the physiology and metabolism of endurance horses

The functional and metabolic processes of the endurance horse are discussed, based on personal experience and the scientific literature. Research on the energetic and physiological aspects of prolonged effort is reviewed, as regards the performance structure, described by Neumann, for human physiology.Experimental data from our previous surveys on endurance horses, competing at different levels, are also presented and discussed.The results on amino acid levels in blood, and related metabolic pathways, during endurance events, lead to speculation on the effects of the race distance on metabolic processes during long-lasting low-intensity exercise. In fact, the event distance has a significant influence on amino acid mobilization and their use as energy sources. In human athletes, the disappearance of some amino acids from blood circulation is linked to the onset of central fatigue. The effect could be similar in endurance horses; therefore, the correct intake of amino acids, and a proper feeding strategy, could improve performance.Data are also provided on dehydration and oxidative stress associated with endurance work.     

Endurance Training Has Little Impact on Mineral Content of the Third Metacarpus in Two-Year-Old Arabian Horses

Although previous research suggests that short bouts of high-speed exercise will increase bone mass in horses, little research has been conducted to determine the impact of endurance exercise on bone. Although many in the equine industry believe that months of slow training will increase bone strength, we hypothesized that endurance training would not alter bone mineral content as determined through optical density. Eleven 2-year-old Arabians were split into two groups, Exercised (E, 6 geldings) or Control (C, 5 fillies), with radiographs taken on day 0 for estimation of bone mineral content by radiographic bone aluminum equivalence (RBAE). The E horses were then trained on a high-speed treadmill for 90 days; training consisted of walking (1.6 m/second), trotting (4 m/second) and cantering (8 m/second) at increasing distances until the target of 60 km/day was met. On day 90, E horses were confined to 9 × 14 m dry lots and placed on a regular exercise schedule, including a 60-km endurance test once every 3 weeks. The C horses remained on pasture throughout the study. On day 162, radiographs were made again on all 11 horses. No differences between treatments, days, or interactions were noted in any cortex or the total RBAE, suggesting that endurance exercise does little to alter bone optical density compared with free-choice exercise on pasture.     

复方丁氨丙磷溶液对小白鼠耐力和能量代谢的影响

为探讨复方丁氨丙磷溶液对动物耐力和能量代谢的影响。采用小白鼠耐寒、耐热、耐缺氧和负荷游泳试验以及用经典蒽酮显色法和反相高效液相色谱法分别测定肝脏和骨骼肌中的糖原含量和3种磷酸腺苷含量，观察复方丁氨丙磷溶液对小白鼠耐力和能量代谢的影响。结果表明：复方丁氨丙磷溶液能明显提高小白鼠耐寒、耐热和耐缺氧能力。明显延长小白鼠负荷游泳时间；能显著提高肝糖原和肌糖原含量以及肝组织和肌肉组织的三磷酸腺苷(ATP)、二磷酸腺苷(ADP)含量。而对肝组织一磷酸腺苷(AMP)含量无明显影响，对肌肉组织一磷酸腺苷含量却有一定的降低作用。说明复方丁氨丙磷溶液是通过提高肝糖原和肌糖原储备以及促进ATP和ADP的合成代谢来增强动物的耐力和能量代谢。     

中国草绣球属和蛛网萼属花粉形态的研究

本文收集了国内虎耳草科（Ｓａｘｉｆｒａｇａｃｅａｅ）中的草绣球属（Ｃａｒｄｉａｎｄｒａ）２种和蛛网萼属（Ｐｌａｔｙｃｒａｔｅｒ）１种植物的花粉,在光学显微镜和扫描电镜下,进行了花粉形态的比较观察。通过研究认为,两属花粉特征较接近,均为近长球形,具３（或拟）孔沟,表面为短刺状雕纹,刺间具明显小孔,说明两属之间的亲缘关系较近,并结合其它一些资料,对两属的系统位置作了初步的探讨。     

蚂蚁水提取物对獭兔耐力的影响

本试验研究了蚂蚁的水提取物对獭兔的耐高温、耐饥饿、抗疲劳、耐乏氧等方面的作用,并与人参的作用效果进行了比较,结果证明,蚂蚁具有明显的抗疲劳作用。     

春用家蚕新品种华·东×春·晨的育成

采用幼虫4龄期人工添食20 mg/kg氟化纳溶液定向选择耐氟污染性能和杂交育种、回交改良等育种技术,育成了具有耐氟污染特性的春用多丝量家蚕新品种华·东×春·晨。该品种在浙江省家蚕新品种实验室共同鉴定和农村生产试验鉴定中,表现出体质强健、耐氟性好、产茧量高、茧型大、丝质优等特点,其中氟敏指数检测数据显示其耐氟性能明显强于春用品种菁松×皓月,并达到了秋用耐氟污染品种秋丰×白玉的水平。新品种在农村生产试验鉴定中,产茧量及丝质成绩普遍优于当地对照品种菁松×皓月和秋丰×白玉,特别是盒种产茧量分别超过对照品种菁松×皓月和秋丰×白玉7%、12%左右。2010年2月该品种已通过浙江省农作物品种审定委员会审定,适合在浙江省及长江中下游蚕区特别是氟化物污染较严重的蚕区春期推广饲养。     

不同除草剂的除草效果及杂草的耐药性

通过对触杀型的割地草、克无踪和内吸型的草甘膦、农达防除苹果园杂草试验结果对比分析,克无踪、农达防除杂草效果良好,割地草、草甘膦防效较差.杂草中多年生的菊科、禾本科杂草耐药性较强,可先喷施触杀型的除草剂,再喷施内吸型的除草剂,可以防除其对果树的危害.