流体静力学的外微分形式

用几何的观点，把微分形式引进流体静力学，从而得到了热力学第一定律的一次形式．并利用外微分的性质，导出了流体静力学的一些基本关系．     

铜绿微囊藻营养动力学研究

铜绿微囊藻是中国湖泊，水库及其他水域生太系统发生，形成富营养化危害的主要藻类。营养盐磷含量及不同温度对铜绿微囊藻生长效应的实验结果表明，氮含量２０ｍｇ．Ｌ＾－＾１条件下，该藻的内禀增长率和生物量随培养液中磷浓度０；０．００１８；０．０１８；０．１８和１．８ｍｇ．Ｌ＾－＾１的升而增加。同时，实验也揭示了细胞内和细胞外高浓度磷营养盐的促进机理。这些结果较好地说明洋河水库的铜绿微囊藻种群从早春到晚秋持续     

Functional investigations of exercising muscle: a noninvasive magnetic resonance spectroscopy-magnetic resonance imaging approach

Muscle fatigue, which is defined as the decline in muscle performance during exercise, may occur at different sites along the pathway from the central nervous system through to the intramuscular contractile machinery. Historically, both impairment of neuromuscular transmission and peripheral alterations within the muscle have been proposed as causative factors of fatigue development. However, according to more recent studies, muscle energetics play a key role in this process. Intramyoplasmic accumulation of inorganic phosphate (P_i) and limitation in ATP availability have been frequently evoked as the main mechanisms leading to fatigue. Although attractive, these hypotheses have been elaborated on the basis of experimental results obtained in vitro, and their physiological relevance has never been clearly demonstrated in vivo. In that context, noninvasive methods such as 31-phosphorus magnetic resonance spectroscopy and surface electromyography have been employed to understand both metabolic and electrical aspects of muscle fatigue under physiological conditions. Mapping of muscles activated during exercise is another interesting issue which can be addressed using magnetic resonance imaging (MRI). Exercise-induced T2 changes have been used in order to locate activated muscles and also as a quantitative index of exercise intensity. The main results related to both issues, i.e. the metabolic and electrical aspects of fatigue and the MRI functional investigation of exercising muscle, are discussed in the present review.Received 4 September 2003; received after revision 4 December 2003; accepted 22 December 2003     

黄头鹡鸰雏鸟生长能学的研究

在黄头 (Motacillacitreola)自然生长状态下 ,通过测定雏鸟气体代谢和身体组织能量积累的方法 ,研究了它们在生长期间的能量投入 .最小能量投入在 0～ 1d (d为日龄 ,用t表示 ) ,为 10 82kJ/d . 1只雏鸟需要能量为 414 2 6kJ,其中生产能为 15 3 14kJ,用于维持的能量是 2 6 1 12kJ .     

黄头脊鸟令鸟产卵能学的研究

在自然生长状态下,用测定在黄头JieLing（Motacilla citreola）成鸟产卵期性腺及输卵管蛋的质量变化的方法,研究了它们在产卵期间的能量投入及其分配形式,产卵期,雌鸟用于性腺增长和卵形成的能量预算为66．24－71．19kJ,其中用于蛋白质和脂肪的能量分别为40．42KJ和25．82-30．78KJ,占总能量预算的56．8％－61．0％和36．3％－46．5％,用于繁殖蛋白的能量分配为：输卵管2．77KJ,卵黄蛋白12．80KJ,卵白蛋白24．85KJ,雌鸟耗能最大的是第0d－＋1d,达（13．28－14．26）KJ／d,产卵期雄耗能（用于性腺增长）7．98KJ,雌雄亲鸟用于卵的形成和性腺增长共投入能量74．22－79．17KJ,雌鸟耗能为雄鸟的8．3倍－8．9倍。     

温度对饥饿状态下南方鲇幼鱼氨氮排泄的影响

于2000年4月至5月,测定了温度对饥饿状态下南方鲇幼鱼(体质量18.4～36.0g)的氨氮排泄的影响.在12.5℃,17.5℃,22.5℃,27.5℃和32.5℃水温下,南方鲇的特殊体质量排氨率分别为1.83,3.86,5.52,7.37和9.29mg/(kg     

改进型阿塞尔轧管机力能参数的测定

作者以大冶钢厂引进的带液压快开系统的阿塞尔轧管机为研究对象,通过对其力能参数(包括轧制力、轧制力矩、脱棒力、电机功率)、轧制速度和轧辊快开时间的测定,摸清了钢种、变形量、牌坊转角、坯料规格和电机转速对其力能参数的影响。     

The hummingbird's restraint: A natural model for weight control

Summary By day, a breeding male hummingbird gives priority to aerial performance over energy security, minimizing body weight gain to expedite flight activity. We observed behavior and monitored weight via perches on electronic balances in a territory with unlimited resources (artificial feeder). The male restricted his first feeding to less than 1/6 of crop capacity. In the ensuing 15 h, his body weight increased only 1% despite an unlimited resource of artificial nectar. This facilitated acceleration for pursuit and courtship flights and reduced energy cost. In 20 min at dusk, an intake of 34% of body weight provided adequate energy for temperature regulation all night. In July, cessation of territorial activity was accompanied by a regular upward drift of dawn weight, suggesting that weight had been regulated previously as a balance between expenditure and intake, perhaps without involving set-points.This research was supported by grants 3242-85 and 3513-87 from the National Geographic Society. Mr William Barber donated Perky-Pet hummingbird feeders. We thank Dana Bradley-Spencer, Ian Billick, Josephine Axt, and Sonda Eastlack for technical assistance. Federal banding permit #8081; Colorado #0063-87-89. Several colleagues and authorities and two anonymous reviewers contributed time and helpful advice following their thoughtful reading of various drafts of this paper. To the extent that their views diverged or our stubbornness persisted, it would unfair to implicate them by names.     

轴向运动结构的能量关系和守恒量研究进展

综述了轴向运动弦线和梁的能量关系和守恒量的研究进展。分别对于横向线性振动、横向非线性振动和耦合平面振动, 确定能量变化的关键量以及轴向运动结构总机械能的时间导数, 结果表明总机械能不是常数。对于上述振动, 构造在振动过程中保持不变的守恒量, 可以用来证明直线平衡位形的稳定性以及检验数值算法。最后提出若干有望取得进展的研究课题。     

锯切过程力能参数的研究

本文由锯切过程中踞屑变形的特点出发,利用剪切面切削模型,给出了锯屑的变形程度和变形速度计算方法。通过分析消耗于锯屑上的能量组成,提出了锯屑的动能消耗不容忽视的观点,并导出了锯切的单位压力公式;根据能耗极小原理,确定了计算模型的主要参数——剪切角φ。最后,本文给出了宏观力能参数的计算方法。通过锯切试验,验证了其合理性。