ASTM D-5307 and ASTM D-7169 SIMDIS Standards: A Comparison and Correlation of Methods

TBP curves are essential in process simulators of the refining industry, particularly for the heaviest fractions of crude oils. ASTM D-7169 and ASTM D-5307 are standards used in simulated distillation analysis for fast characterization of these fractions. In this report, correlations to convert data from the first one to the second-mentioned standard are reported. These correlations were obtained from our analytical laboratory and pilot plant experimental data, gathered so far.     

硅油式防滑差速器特性对汽车操纵性能的影响研究

为了研究硅油式防滑差速器的转矩输出特性,通过电控动力传动系试验台对硅油式防滑差速器转矩输出特性进行了测定试验。通过仿真对比试验测定汽车转弯半径比、横摆角速度及侧向加速度等,并作为对比参数来考察硅油式防滑差速器转矩特性对汽车操纵稳定性的影响。仿真试验结果表明,若硅油式防滑差速器的防滑转矩设计合适,汽车装硅油式防滑差速器比装普通差速器更有利于汽车的操纵稳定性。     

基于粘性阻尼的地埋式旋转喷头限速系统研究

介绍了现有地埋式旋转喷头的结构及其减速机构的工作原理,分析并指出了其存在的传动比大、效率低下等不足.在此基础上,开发了一种基于粘性阻尼传动的新型限速机构,基于数学模型的仿真分析表明其输出转矩与转速成近似正比关系,具有良好的调节线性和稳定性,能够显著提高喷头输出转速的平稳性,并且具有低成本、高效率的优点,可满足农作需要.     

Effect of damping model on pre-yielding earthquake response of structures

The present paper examines differences between responses of single-degree-of-freedom (SDOF) systems with viscous and hysteretic damping to earthquake ground motions. Only responses within yield limits are considered. The structural behavior of SDOF systems with hysteretic damping is modeled by a generalized elasto-slip model of the Masing type. The model leads to a force–displacement relationship similar to that proposed by Ramberg and Osgood. The responses of the two systems are compared for a number of earthquake records. To achieve consistent comparison, parameters of the linear system with viscous damping are determined by the secant stiffness method. In many cases significant differences in the peak displacement responses and energy values have been observed between the systems. This indicates that the prediction of the response of structures to earthquake ground motions before yielding based on linear models with viscous damping may not be as accurate as used to be believed. Tentative estimates of error associated with such predictions are presented.     

螺杆泵在稠油出砂井中的应用

本文介绍了螺杆泵采油系统基本结构和工作原理，根据螺杆泵在稠油出砂井中的现场应用，分析了螺杆泵现场应用效果以及现场施工时要求，展现了螺杆泵采油系统在高粘稠油和出砂井等方面良好的现场应用前景。     

对拓宽油气资源领域的一点意见

我国油气工业的发展在于：①逆冲断裂带的勘探。②非构造类型油气藏的勘探，如岩性油藏、尖灭油藏、水动力油藏等。这两类领域的勘探要提高地球物理勘探工作的水平。③水合物天然气藏应给予足够的注意。国外开采特稠油油藏的经验要注意学习，为我所用。（秦同洛摘     

粘性不可压流动的全离散非线性Galerkin方法

这篇文章讨论了有限元情形下，粘性不可压流动的全离散非线性Ｇａｌｅｒｋｉｎ方法，此外，给出了用非线性Ｇａｌｅｒｋｉｎ方法进行的数值试验结果，和通常的Ｇａｌｅｒｋｉｎ方法比较，非线性Ｇａｌｅｒｋｉｎ方法是一种稳定性好，计算量少以及逼近精度高的数值方法。     

A boundary element study of the effect of surface dissolution on the evolution of immiscible viscous fingering within a Hele-Shaw cell

Fingering instabilities at the interface between two immiscible fluids can appear during the displacement of a fluid of higher viscosity by another one of lower viscosity. The evolution of the finger structures is determined by the interface kinematic and dynamic matching conditions, which describe mass and momentum conservation across the interface. In the case when the injected fluid is a gas and the resident one is a liquid, dissolution of the injected gas into the displaced liquid can occur at the interface between the two phases. In this case, the transfer velocity of the dissolved gas reduces the interface displacement velocity as described by the kinematic matching condition, delaying the evolution of the fingering. In addition, the momentum flux across the interface, due to the dissolution, modifies the dynamic matching condition with possible changes in the patterns of the fingers structures.This work studies the effects of gas dissolution on the evolution of fingering instabilities during the displacement of a viscous liquid by an immiscible injected gas in a Hele-Shaw cell. A boundary element numerical simulation of the growth of the injected gas bubble is developed and implemented. This numerical model takes into account the dissolution across a sharp interface between the two phases. Our numerical simulations suggest that the inclusion of gas dissolution can lead to the eventual breaking of the fingers. These “shed fingers” become individual bubbles, which move away from the injection source with the velocity of the surrounding fluid and eventually will dissolve into the ambient fluid. New fingers evolve, with their concurrent breaking, resulting in the possibility of a cascade of travelling and dissolving bubbles, instead of a continuous fingering structure.     

稠油油藏蒸汽吞吐年油汽比的变化规律及其预测方法

以辽河油区已投入吞吐开采稠油油藏实际一切数据为基础，总结了年油汽比变化规律，建立其动态预测的数学模型，并用推广递推梯度方法，对模型中的参数进行了估计。     

Studies on Nigerian Crudes. II. Physical Characteristics and Rheological Properties of Residual Asphalts

The characteristics of some residual asphalts samples obtained from Nigerian medium and heavy crudes were studied using ASTM/IP standard tests. The residual asphalts were compared with industrial solid grade asphalts and cut back samples. Penetration and softening point tests performed on the treated samples showed that some of these samples fall within the range of road paving asphalts while sample having a low temperature susceptibility was found to be of better than the solid grade asphalt. The rheological behavior of an asphalt sample was investigated using a rotational viscometer. The sample showed a complex non-Newtonian character with structural breakdown as temperature is raised above its softening point. The study further confirmed the suitability of Nigerian medium crudes for the production of road paving asphalts.