A novel arterial Wick for gas–liquid phase separation

Gas–liquid phase separation under microgravity conditions or in small-scale fluidic systems represents a challenge for two-phase liquid-continuous systems. In this study, capillary channels formed by 3-mm diameter stretched stainless-steel springs coated with a commercial superhydrophobic coating are used to remove air bubbles from water. A single channel is capable of absorbing a stream of 3.7-mm diameter bubbles impinging on a small area of the channel at a rate of over 50 bubbles/s. High-permeability walls lead to fast individual absorption events (4 ms for 2.5-mm bubbles) where bubble collapse time is limited by the inertia of the surrounding liquid. A horizontal three-channel array has been shown capable of absorbing impinging bubbles from a sparger at superficial gas velocities of 0.03 m/s. The ultimate capacity of the 3-mm diameter channel is predicted to be much higher than what could be measured with the existing apparatus. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1340–1354, 2019     

不同混凝土浇筑成型方式下高耸进水塔结构动力特性

为探究不同混凝土浇筑成型方式对进水塔的影响,使用时程分析法计算了地震作用下进水塔结构在不同浇筑成型方式下的动力响应,分析了塔体的动力特性,研究了浇筑成型方式对进水塔结构应力、位移的影响。结果表明,整体浇筑时进水塔横梁、拦污栅墩、纵梁处的第一主应力较分开浇筑时有较大改善;塔体与塔背回填混凝土整体浇筑时进水塔顺河向、竖向、横河向的位移最大值较分开浇筑时有一定幅度的减小;采用塔体与塔背回填混凝土整体浇筑的浇筑成型方式,能有效降低进水塔结构的位移与应力,对其抗震性能的改善具有重要作用。     

一种非均质油藏油水界面的简便计算方法－以冀东油田南堡1-1区为例

单一油藏中油水界面是一个起伏的曲面,单井油水界面深度的准确计算对于油藏精细开发有着重要意义。在现有油水界面确定方法的基础上,采用多种方法联合确定油水界面。选取油藏上油水界面已确定的井为参考井；基于受力平衡方程式,建立计算井与参考井相对油水界面深度关系表达式；利用毛管压力与储层物性的关系,将计算参数转化为油田开发中常用的测井解释孔隙度、渗透率。该方法计算所需参数少,实际应用证实了方法的计算精度较高,是一种计算非均质油藏油水界面深度的简便方法。     

Effect of hydrogen on explosion characteristics of liquefied petroleum gas-air mixtures

The effects of hydrogen addition on the explosion characteristics of liquefied petroleum gas (LPG)-air mixtures were experimentally investigated under initial conditions of 1 atm and 298 K. Furthermore, with reference to the detailed USC-Mech II mechanism, sensitivity and the rate of production (ROP) analyses were conducted. When the hydrogen proportion is constant, the maximum explosion pressure and the maximum rate of pressure rise first increase and then decrease, reaching peaks at an equivalence ratio of 1.3. The experimentally measured maximum explosion pressure is lower than the numerically calculated adiabatic pressure. The calculated adiabatic pressure decreases slightly with an increase in the hydrogen proportion. However, under the experimental conditions, owing to the high reactivity of hydrogen, the LPG-H₂-air mixtures experience a small heat loss in the early stage of the explosion, and the maximum explosion pressure and maximum rate of pressure increase considerably, with the arrival time of the pressure peak is advanced. The addition of hydrogen promotes the sensitivity coefficient of reactants C₃H₈ and C₄H₁₀ and increases the maximum ROP of free radicals H, O, and OH. Meanwhile, the addition of hydrogen significantly influences the maximum ROP of the elementary reaction R2.     

Intensification of liquid–liquid two-phase mass transfer in a capillary microreactor system

A convenient strategy to intensify the liquid–liquid mass transfer performance in a capillary microreactor system was developed by narrowing the inlet channel of T-micromixer or adding baffles into the capillary. Various geometrical parameters such as the inlet mode and diameter of the modified T-micromixer, the number of baffles and interval distance between baffles in the modified capillary were investigated to elaborate the mass transfer intensification mechanism. The liquid–liquid two-phase flow patterns in new capillary microreactors were captured by a high-speed camera. Moreover, pressure drops and specific energy dissipation of these modified microreactor systems were studied and a new parameter indicating the ratio of the mass transfer coefficient to the energy dissipation was proposed. This work highlights the modified capillary microreactor systems with embedding baffle units for achieving high mass transfer rates with its advantages over other types of reactors or microreactors considering specific energy dissipation and effective energy utilization efficiency. © 2018 American Institute of Chemical Engineers AIChE J, 65: 334–346, 2019     

基于AHFO技术的毛细水运移模型验证试验研究

为了验证常用的描述毛细水运移模型的准确性,设计了室内模型试验,采用主动加热光纤法(简称AHFO)对砂土模型中的毛细水运移进行了测试。根据测试结果,分析了毛细水入渗模型Green-Ampt模型、Terzaghi毛细水上升模型和毛细水最大上升高度预测模型Lane模型、Peck模型的特点和预测精度。试验分析结果表明:对于砂性土,毛细水上升过程可以分为两个阶段,第一阶段(约前50 h),Green-Ampt模型和Terzaghi毛细水上升模型预测的毛细水上升高度值均低于实测值,Terzaghi模型拟合精度高于Green-Ampt模型;第二阶段(约50h后),Green-Ampt模型和Terzaghi模型预测值均高于实测值,且Green-Ampt模型拟合精度高于Terzaghi模型。这两个模型预测精度随时间的变化现象是与其所用的假设条件和土体物理性质变化有关。Peck模型的误差低于Lane模型,为2.60 cm,而Lane模型由于只考虑了有效粒径D10,误差高达8.58 cm。利用Green-Ampt模型可反演土的饱和渗透系数与湿润锋处基质吸力。研究成果为常用毛细水运移模型选择和误差分析提供了实测依据。     

Thermal effects in compressible viscous flow in a capillary

The thermal effects for a compressible viscous flow in a capillary have been calculated by solving the equation of energy, where a parabolic profile is assumed for the axial flow velocity. It is shown that, in general, the temperature changes are small (a few millikelvins), consistent with the current assumption of an isothermal flow, except in the case of a critical, i.e., very compressible, fluid where the cooling can be substantial. This effect is demonstrated numerically on the basis of a flow of ethylene in nearly critical circumstances.Paper dedicated to Professor Joseph Kestin.     

电视图像运动响应特性的参数选择及其测量

从活动图像运动响应的定义出发,分析种种运动伪像成因,提出描述运动伪像的5个实用参数,阐明选择其中亮拖尾时间和暗拖尾时间作为电视机指标参数的理由,并就它们一种低成本的实用测量方法做了介绍和说明。     

Protein and Amino Acid Profiles in Natural and Artificial Shark Fins using Capillary Electrophoresis

The potential utility of capillary electrophoresis (CE) for differentiation between natural and artificial shark fins was established. Three major protein components (peaks I-III) of shark fins were well-separated and used as parameters for differentiation between natural and artificial shark fins. The height ratio of protein peak III to protein peak I was higher in natural shark fins than that in artificial products. Further, the profile of amino acids in natural dried shark fins was somewhat different from that in artificial samples. The level of tyrosine was especially high (5.11-8.11%) in natural dried shark fins, but low or not detectable (0-0.22%) in artificial samples.     

纽约世贸中心用厚板钢剖析及对宝钢建筑用厚板开发的启示

采集了一组来自纽约世贸中心废墟的不同厚度的废钢样块，分析了该大厦建筑用厚板钢的化学成分、机械性能及金相组织，并结合国内高层用厚板钢市场的调研，探讨了宝钢建筑用宽厚板开发中应注意的相关事宜。