低温乏汽回收利用装置的结构参数研究

通过实验研究了收缩角,喉嘴面积比和汽、水喷嘴面积比3个结构参数变化对低温乏汽回收利用装置性能的影响规律.研究发现存在最佳汽、水喷嘴面积比使装置的性能最好,但不同进口工质参数下的最佳汽、水喷嘴面积比值不同;随着收缩角(14°~22.7°)的增大,引射系数逐渐降低,而阻力系数呈现出升高的趋势,并且不同收缩角对应的最佳汽、水喷嘴面积比值随着收缩角的增大逐渐减小;引射系数随着喉嘴面积比(1~5.44)的增加而升高,阻力系数却先降低后升高.这些研究结果为低温乏汽回收利用装置的优化设计和工业应用奠定了基础.     

二元混合流掺气特性初步研究

本文利用最近研制成功的微电脑掺气浓度实时量测和数据处理系统,对混合流各序列流态的掺气浓度进行了量测,分析了混合流掺气浓度的分布规律、从而证明了混合流确系射流与水跃流的混合流动。同时还初步探明局部水力现象中自掺气的结果,与消能效果之间并不存在必然的联系。     

Entrainment of human circadian rhythms by artificial bright light cycles

Summary Artificial bright light cycles (LD 816) of about 5000 lux during the light period were applied to two subjects in a temporal isolation unit, who had shown free-running circadian rhythms in sleep-wakefulness and rectal temperature. The circadian rhythms were successfully entrained by the artificial light cycle, but the phase relation of the rhythms to the light cycle was substantially different between the two subjects. The result indicated that the artificial bright lights are able to reset human circadian rhythms.     

The role of sediment resuspension duration in release of PAHs

Polycyclic aromatic hydrocarbons （PAHs） are ubiquitous environmental pollutants. Due to their low water solubility and high hydrophobicity, PAHs are rapidly sorbed onto particles and subsequently deposit in sediments once introduced into aquatic environment. In such a way, sediments become a huge sink for PAHs. During sediment resuspension, the potential exists for PAHs to be released from sediments into water. Sediment resuspension plays an important role in the transportation and fate of PAHs in the aquatic environment. In this study, release behavior of PAHs on Yangtze River sediment during resuspension was investigated using a particle entrainment simulator （PES）. The role of resuspension duration on release of 16 PAHs was measured by resuspending sediment for 12 h at 0.2 and 0.5N/m^2, respectively. Results indicated that PAH concentrations in TSS increase over time with more increase of phenanthrene and 4-ring PAHs. Comparing with 0.2 N/m2 （30%）, TPAHs concentrations in TSS demonstrated remarkable increase during 0.5 N/m2 resuspension （37%）. Dissolved PAH concentrations increased throughout the duration with more increase of 2-3 ring PAHs （50%-88%）. Dissolved PAH concentrations showed remarkable increase during 0.5 N/m^2 resuspension （50%）. Moreover, PAH concentrations in overlying water throughout the duration of resuspension were higher than toxic effects threshold values in drinking water developed by WHO, which may cause toxic effect on ecosystem.     

Aging alters resynchronization of the circadian system in rats after a shift of the light-dark cycle

Summary Four days following an 8-h advance of the light-dark cycle, the circadian rhythms in the pineal N-acetyltransferase activity and melatonin content reappeared in 7-week-old rats, but were still abolished in 24-month-old animals.     

烟气自循环式低氧燃烧器燃烧过程的数值模拟

在分析了工业中几种低氧燃烧方式的基础上,将收缩-扩张结构用于燃烧器空气通道,开发出了烟气自循环式低氧燃烧器,同时借助FLUENT软件对燃烧器进行了大量数值模拟研究. 结果表明:喉部的负压是烟气卷吸的驱动力,烟气卷吸量随喉部面积的缩小而急剧增多;随着烟气卷吸量的增多,炉膛中氧含量越来越低,火焰高温区向燃烧器偏移,火焰逐渐变短. 最后,将烟气自循环式低氧燃烧器用于熔化保温炉进行了实践,取得了预期的效果.     

出钢过程中注入流体卷入气体的模拟研究

利用相似原理建立水力学模型,模拟了出钢过程中注入流体卷入气体的过程。模拟实验结果表明,注入时间愈短,注流带入的气体量愈少;注入高度愈低,注流带入的气体量愈少。并分析了流体注入时间、注入高度对流场的影响。     

引导系统到任意目标

提出对系统同时施加开环控制与参数调节可将系统轨道引导到任意目标函数，此方法能实现仅开环控制无法完成的目标函数传输，其功能与开环加闭环方法完全一样。同时给出了Ｌｏｒｅｎｚ，Ｒｏｓｓｌｅｒ及Ｄｕｆｆｉｎｇ等系统的传输域。     

钝体后回流区涡旋结构初探

首先对钝体后的涡旋结构进行了探讨，然后应用涡通量守恒定理对钝体后的涡旋度和回流区面积之间的关系作了初步分析，从瞬时和平均两种意义上对回流区面积和竖直卷吸速度沿规则等腰钝体高度方向的变化规律给出了理论解释