均匀设计方法在磷肥疏松剂配方上的应用研究

采用均匀设计方法进行了磷肥疏松剂配方实验方案的设计及实验结果的优化,结果表明该方法可以用最少的实验次数得到最佳的配方。10g疏松剂的活性组分最佳配方为:造纸废液0·85g,硝酸盐0·05g,十二烷基苯磺酸钠0·768g,十二烷基磺酸钠0·043g,OP-10为0·572g,KCl为0·056g。实验表明,制备的疏松剂防结块效果好于市售的疏松剂,并且降低了成本。     

氧化铝纳米流体液滴瞬态蒸发速率的演化特性分析

以氧化铝纳米流体液滴为研究对象,本文建立了基于任意拉格朗日-欧拉（ALE）法的液滴蒸发瞬态模型,对液滴蒸发过程中蒸汽浓度、纳米颗粒浓度、温度等进行多物理场耦合,并考虑了Marangoni流对液滴蒸发的影响,同时研究还结合蒸发实验可视化结果,分析了氧化铝纳米流体液滴的瞬态蒸发速率随时间的演化规律,讨论了颗粒体积分数和基板温度对蒸发模式的影响。结果表明,在液滴蒸发过程开始时,纳米流体液滴保持定接触半径蒸发模式,气液界面面积逐渐减小,瞬态蒸发速率也呈逐渐减小的趋势;当颗粒体积分数增大至26%时,瞬态蒸发速率曲线达到驻点;蒸发接近完全时,由于Marangoni流影响了内部流场、强化了内部传热,且液滴在已沉积在基板上的颗粒表面形成液膜,瞬态蒸发速率迅速增大。     

驱油剂对中间层原油乳状液稳定性的影响

考察了孤岛油田中间层原油和外输原油的稳定性差异以及驱油剂对原油乳状液稳定性的影响.对于同一种破乳剂TA1031,在相同的脱水条件下,外输原油与中间层原油的最终脱水率分别为95.48％和78.40％,加入二元复合驱之后,脱水率分别为83.33％和70.30％.随着驱油剂浓度的增加,zeta电位的负值越来越大,乳状液稳定性...     

An experimental study of the effect of water content on combustion of coal tar/water emulsion droplets

Isolated high asphaltene droplets of coal tar/water emulsion were studied to investigate the non-steady behavior of the burning droplets. Data on size and temperature histories were obtained. Coke residues were analyzed by scanning electron microscope. Lower and upper limits for ignition time delay were established. The error, defined as the time lag between these two limits, was less than 8 ms. Ignition time delays of emulsions were longer than for ordinary coal tar (CT) droplets of the same size but the peak temperature of emulsions occurred much earlier. A steeper temperature rise observed in the emulsions during portions of their combustion history is evidence not only of soot reduction but also the extent of burnout of the cenospheres. The latter is an important aspect in the reduction of pollutant emissions. The emulsion droplets indicated swelling of considerable magnitude compared with that of CT. Coke particles formed from emulsions were more porous, with thinner and fragile shells. The CT residues were harder and more resistant to burning. Excess burnout time or the ratio of burnout time of the emulsions depended on the water concentration, indicating that longer oxidation time was required for coke particles from coal tar than from emulsions.     

Online scheduling on two uniform machines subject to eligibility constraints

We consider the online scheduling of a set of jobs on two uniform machines with the makespan as objective. The jobs are presented in a list. We consider two different eligibility constraint set assumptions, namely (i) arbitrary eligibility constraints and (ii) Grade of Service (GoS) eligibility constraints. In the first case, we prove that the High Speed Machine First (HSF) algorithm, which assigns jobs to the eligible machine that has the highest speed, is optimal. With regard to the second case, we point out an error in [M. Liu et al., Online scheduling on two uniform machines to minimize the makespan, Theoretical Computer Science 410 (21–23) (2009) 2099–2109]; we then provide tighter lower bounds and present algorithms with worst-case analysis for various ranges of machine speeds.     

Validation of Solids Suspension Viscosity Measurements Using Computational Fluid Dynamics

Accurately measuring the viscosity of a solids suspension requires uniform suspension of the solids in the viscometer cup. In a cup‐and‐impeller viscometer system, solids may settle when the impeller speed is too low, causing viscosity measurements to appear lower than that of a well‐suspended slurry. Pre‐mixing of a solids suspension is typically performed to achieve steady state prior to measurements. Data here shows that the measured viscosity values differ depending on the pre‐mixing speed, indicating that the solids are not properly suspended at all speeds. A commonly used cup‐and‐vane impeller system can be thought of as a mixing tank that should operate above the uniform‐suspension speed (USS), although determining the USS experimentally is rather subjective. Computational fluid dynamics (CFD) is employed here to determine the USS of a pretreated corn stover (PCS) solids suspension and to confirm the experimentally measured USS.     

随机分布模式的统计检验

为了研究模式的聚类趋势问题,本文定义一种适用于随机分布模式(均匀分布和高斯分布)的统计检验方法。Monte-Carlo模拟结果证明了该方法的合理性。     

环形气隙中长直载流导线磁场的级数解及应用

本文首先采用分离变量法推导了位于定、转子间均匀环形气除中单根长直载流导线磁场的级数解；然后介绍了应用该级数解计算电机电枢反应磁场、永磁场的方法；最后应用该级数解获得了考虑定、转子曲率影响的均匀气隙电机不饱和主电抗与谐波电抗表达式。比较表明，当电机气隙和定、转子半径可比拟（尤其对于极对数较大的情况）时，考虑与不考虑定、转子曲率两种计算方法给出的不饱和主电抗、谐波电抗之间存在巨大的差异。考虑定、转子曲率时的计算结果更加接近实测结果。