混凝土渠道糙率原型观测

糙率是渠道水力设计的关键技术参数之一，其值的准确选取决于已建工程原型观测成果的类比。选择3条不同衬砌特性的混凝土渠道进行糙率原型观测，对观测方法及步骤做了较详细描述；计算出了3条渠道的糙率，对其存在误差进行了分析探讨，可为今后进一步开展相关课题研究积累经验并供同行参考。     

啤酒酵母菌种的石蜡保藏技术

啤酒酵母菌种用液体石蜡技术保藏具有设备简单、操作方便,成活率高,变异少,优良种性能保持较长时间的优点,实用价值高。本文从液体石蜡保藏菌种的机理、保藏效果、保藏等具体技术操作及其使用方法都作了较为详细的介绍,相信能为啤酒菌种的保藏带来较大的好处。     

神经网络在缺陷识别中的应用

为了准确、快速地进行缺陷识别，介绍了一种新型的前馈神经网络模型，即径向基概率神经网络。与以往的算法相比，该方法具有分类识别精度高且速度快的优点。仿真获得了很好的结果。     

Corresponding states correlation of saturated and metastable properties

A corresponding states correlation is developed for the p - v - T properties of saturated liquids. It is similar in form to a previous correlation; however it is more accurate in the low pressure, low Pitzer factor range, owing to the incorporation of new information about low Pitzer factor behavior. The problem of creating corresponding states correlations of the spinodal lines and the metastable states is also discussed in the light of new equation of state information. A partial preliminary correlation works particularly well for non-polar molecules in the range of fairly small positive Pitzer factors.     

Onset of buoyancy-driven convection in melting from below

When a horizontal homogeneous solid is melted from below, convection can be induced in a thermally unstable melt layer. In this study the onset of buoyancy-driven convection during time-dependent melting is investigated by using similarly transformed disturbance equations. The critical Rayleigh numbers based on the melt-layer thickness are found numerically for various conditions. For small superheats, the present predictions approach the well known results of classical Rayleigh-Bénard problems, that is, critical Rayleigh numbers are located between 1,296 and 1,708, regardless of the Prandtl number. However, for high superheats the critical Rayleigh number increases with an increase in phase change rate but with decrease in Prandtl number.     

新疆油田微生物开采稠油技术研究及矿场试验

通过室内筛选复壮,选育出对克拉玛依稠油具有显著降粘作用的微生物菌种.室内降粘实验结果表明,菌种对稠油的降粘率可达70%,同时菌种可以改善稠油的流体性质.原油族组分分析结果表明,菌种能够降解稠油中的非烃和长链饱和烃.首次在克拉玛依油田进行了6口井的微生物吞吐开采稠油矿场试验,累计增油865t.     

Characteristics of Milk Powders Produced by Spray Freeze Drying

Skim and whole milk powders were manufactured at lab scale by spray freeze drying (SFD), using liquid nitrogen as the cryogen. The polydispersity of droplet/particle sizes was limited using an encapsulator nozzle to atomize the feed. Particle morphology was examined using a scanning electron microscope. Samples were compared with equivalent spray-dried powders in tests of wettability and dissolution in water. The spray freeze-dried powders were found to be highly porous, with a uniform structure of pores throughout the entire particles. When tested in water, SFD skim milk powders wetted roughly three times as fast as industrially spray-dried agglomerated skim milk powders and were observed to dissolve rapidly by breaking down into smaller particles.