Filtration of Non-Newtonian Hydrocarbon Fluid in a High-Frequency Electromagnetic Field

The paper gives the results of experimental investigations of the initial pressure gradient of bituminous oil and the time dependences of variation of the temperature in a formation model and of the well production rate in a microwave-frequency electromagnetic field. The effect of strong decay of the non-Newtonian properties of bituminous oil is revealed. The nonuniformity of temperature distribution over the formation thickness is demonstrated, which depends on the initial production rate of the well and on the duration of stimulation of the bottom-hole zone of formation.     

黑岱沟露天矿重型汽车预防性维修的探讨

通过对黑岱沟露天煤矿运输设备出动率调查,初步分析了目前主要运输设备的现状以及存在问题的原因和影响因素,就加大预防性维修的比重,实行全面的预防性维修制度提出了一些看法。     

东方N-18250-2型凝汽器胶球清洗系统改造

对湘潭电厂存在已久的胶球清洗装置收球率低的问题进行了深入探讨，结合电厂对胶球清洗系统的改造、试验过程，分析并提出了影响胶球清洗装置清洗效果及收球率的诸多原因及其解决方法。     

德国联邦物理技术研究院(PTB)气体微流量计量评介

在真空技术应用中 ,高精度气体微流量计用于连续膨胀法校准系统压力的产生、漏孔漏率的测量以及真空泵抽速的测定。PTB先后研制了三代气体微流量计 ,第一代为手动型 ,第二代为半自动型 ,第三代为全自动型。本文详细介绍了PTB研制的气体微流量计的性能和特点 ,并介绍了气体微流量计在真空漏孔的漏率测量方面的应用。另外 ,还介绍了PTB最近研制的大气压力下漏孔漏率测量系统的性能和特点     

BFG的热值及温度与0号机出力和效率的关系

分析煤气温度、干煤气热值和湿煤气热值之间的关系，得到0号机组长期达不到额定出力和效率的原因，在此基础上提出解决问题的方法。     

最优特征子集选择问题

机器学习和模式识别面临的一个重要问题，就是特征子集的选择问题，即从一个大的已生征特集合，选择一个子集合来一致地描述已知例。特别，最优特征子集选择问题，即最小的特征子集问题的 计算杂性至今学不清楚。     

难处理金矿石加石灰焙烧焙砂中CaS的消除

介绍了用空气氧化预浸加石灰焙烧焙砂中的CaS，以消除其对金氰化的影响。预浸后金的氰化浸出率可从58％提高到80％以上。     

高效率平面磁控溅射器的研制

介绍一种新型磁控溅射装置。它采用两块极性相对的环状磁铁的设计方法，通过扩大靶表面的等离子放电区域面积，使传统磁控溅射枪使用中经常受到的两个限制──溅射速率与靶的利用率得到了较大的改善。实验中铜靶在溅射功率密度为11W／cm~2时溅射速率约为800nm／min，如果继续提高功率则可获得更高的速率。而靶的利用率可达64％左右。另外，在认为出射粒子符合cos~nθ分布的前提下，发现当n＝3．3时，实验数据和理论数据符合得较好。     

A simple conceptual model for predicting the dissolution of phosphate rock in soils

Laboratory experimental and literature data were integrated to develop a simple, conceptual model to describe and predict the dissolution of a reactive phosphate rock (Gafsa phosphate rock, GPR) in soils. The model showed that initial solution Ca concentration strongly influences the time required for a single application of GPR (at 30 kgP ha^?1) to dissolve. The model predicts that all of the GPR will dissolve within a year of application in an unlimed, acid (pH_w 4.5) loam. However, if the soil has previously been limed to (pH_w 5.8, and contains permanent charge only, the model predicts that only about 50% of the GPR would have dissolved by the end of the second year after application. On the other hand, if a previously limed soil ((pH_w 5.8) contains variable-charge components, the model predicts that virtually all of the GPR would have dissolved in this soil by the end of the second year after application. These results emphasise that, even in the presence of a high proton supply, solution Ca has an overriding influence on the dissolution of GPR. The faster rate of GPR dissolution in the limed soil with variable charge, compared to that in the limed soil with permanent charge only, demonstrates the ability of the variable-charge component of soil to act as a sink for some of the lime-derived Ca. According to the solubility product principle, this allows more GPR to dissolve. Because of the generally stronger buffering of soil for P than for Ca, a relatively large proportion of any P removed by leaching and plant uptake is buffered by the sorbed phase. Consequently, the influence of leaching and plant uptake on GPR dissolution is attributed primarily to the removal of the relatively less-strongly buffered Ca.