Knee extensor and flexor torque development with concentric and eccentric isokinetic training

This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1). Eccentric training increased ECC knee extension and flexion peak torque more than CON training. The ECC group improved acceleration time and time to peak torque with ECC movements versus the CON group. Slow-velocity ECC isokinetic training yielded greater ECC and similar CON torque development gains versus CON training over the course of 20 weeks in young women.     

荣毅仁与改革开放

一个窗口,涂着温馨的巧克力的颜色; 　　主人微笑着,从窗口向世界招手…… 　　今年是我国实行改革开放的30周年,人们自然会想起当初作为这一战略性抉择的一项重要举措与标志--荣毅仁和他领导的中国国际信托投资公司.……     

The non-molecular structure of solids

To sum up our argument then: It is shown, in the first place, that the arrangement of the atoms in certain crystals, as determined by the X-ray spectra, indicates definitely that in these crystals there is no molecular structure.In extending the argument to all solid matter it is pointed out, from the dependence of crystal form on chemical composition, from a consideration of the Dulong-Petit law and of the nature of cohesion, and from the evidence of X-rays as to certain crystals, that each atom in a solid oscillates about a definite position of stable equilibrium.From a further examination of the nature of cohesion and of the forces concerned in chemical combination and especially from the general relation found between the atomic heat of formation of a substance and its melting-point it is found that the forces holding the atoms in their positions of stable equilibrium are of the same nature and comparable in magnitude with the forces binding together a chemical molecule.It is seen further that the atoms in a solid are very close together so that they often come in contact. And, since an atom attracts equally all atoms of another kind which are in contact with it, an atom cannot remain combined for more than an infinitesimal interval with any other particular atom ordinary temperatures.Finally, it was shown that, since in the solid state each atom has three degrees of translational freedom and is strongly attracted by atoms other than those of its own “molecule,” it must, on the average, exert equal attractions on all the neighboring atoms.From this the conclusion is drawn that in the particular molecules cannot be definitely defined.When those properties of solid matter which have been explained by molecules are considered, nothing is found which indicates at all definitely a molecular structure.We feel justified in concluding, therefore, that the structure of solid matter is not molecular.