Dynamical correlations and the direct summation method of evaluating infinite continued fractions

Testes from 11.5-day-old mouse embryos, with and without attached mesonephroi, were cultured for 7 days. Isolated testes failed to develop well-differentiated testis cords: however, when cultured attached to a mesonephros from either a male or a female donor embryo, testes developed cords that were normal in appearance. Testes cultured next to a mesonephric region but separated from it by a permeable filter, did not develop normal cords, nor did testes grafted to fragments of embryonic limb or heart. When testes were grafted to mesonephric regions from mice carrying a transgenic marker, the marker was found in some of the peritubular myoid cells and other interstitial cells of the testis, but not in the Sertoli cells or the germ cells. We conclude that after 11.5 days post coitum, cells can migrate from the mesonephric region into the differentiating testis and can contribute to the interstitial cell population, and that this contribution is necessary for the establishment of normal cord structure. The germ cells in all cultured testes, whether or not differentiated cords were present, were T1 prospermatogonia: no meiotic germ cells were seen.     

Studies of photoconductivity in β-Apo-8′ carotenal

The photoconductive properties of a carotenoid polyene,β-Apo-8′ carotenal in polycrystalline form has been studied. The growth of the photocurrent shows an overshoot in the growth-time curve before steady state value is attained. This behaviour of photocurrent is proposed to be due to higher value of recombination coefficient than trapping coefficient. From the temperature dependence study it is observed that the steady state photocurrent, at first increases with increase of temperature, attains a maximum at a particular temperatureT _max and then decreases with temperature. TheT _max value agrees with the temperature above and below which steady state photocurrent is attained differently. Monomolecular and bimolecular recombination processes at two temperature regimes are proposed to account for the observed behaviour. The dependence of photocurrent with excitation light intensity and wavelength study provide information on the carrier generation processes. The fast decay of photocurrent have been observed at different temperatures and from this study the decay constant is calculated and it is found to be temperature independent.     

Effects of triiodothyronine (T3) supplementation upon ozone-induced lung injury

Ozone exposure results in an acute decrease in the serum levels of thyroid hormones; the physiologic sequelae of this are unclear. Whereas thyroid hormone supplementation appears to benefit pulmonary function in septic, oxyradical models of injury, thyroid hormone increases ozone toxicity. We demonstrated an increase in metabolic rate and pulmonary injury in lungs from ozone exposed, T3 treated animals. This was evidenced by an increase in pulmonary weight gain, vascular perfusion pressure, and decrease in compliance in the supplemented animals. However, an increase in alkane generation, as an index of lipid peroxidation, was not seen in the ozone exposed, hormonally treated animals. This suggests that although thyroid hormone supplementation increases metabolic rate and ozone toxicity, an increased rate of lipid peroxidation plays a minimal role.     

交流·阅读文稿·互动——书籍整体设计伊始的两个重要环节

忽视书籍整体设计前与写作者的交流、阅读文稿这两个环节,无疑会对设计过程造成很大的设计障碍。“限制”与“反限制”于当代设计中是设计师所必须要面临的现实问题。克服被“限制”的思维定式,以“限制”为设计创想的起始点,使设计更准确地表现被设计物的气质,同时又能充分表现设计师独具的设计表现风貌、协助销售,使设计与销售达成双赢的结果,此为时代要求使然。     

车辆生产中军转民有关问题探讨

本文指出了从军用车辆生产转向民用车辆生产是一个技术与经济的过程；论述了尽快完成这一过程所必须解决的技术创新问题，生产方式问题和投资多元化问题．