Diffusioosmotic flow of electrolyte solutions in fibrous porous media at arbitrary zeta potential and double-layer thickness

The diffusioosmosis of electrolyte solutions in the fibrous medium constructed by a homogeneous assemblage of parallel, charged, circular cylinders caused by a uniform concentration gradient prescribed in their axial direction is studied theoretically. The electric double layers adjacent to the cylinders may have an arbitrary thickness. A unit cell model is used to account for the interaction effect among the cylinders. The electrostatic potential distribution in the fluid phase is determined with an analytical approximation to the solution of the Poisson–Boltzmann equation. By solving the fluid momentum equation with the constraint of no net electric current arising from the co-current diffusion, electric migration, and diffusioosmotic convection of the electrolyte ions, the macroscopic electric field and the fluid velocity in the axial direction induced by the applied electrolyte concentration gradient are obtained semi-analytically as functions of the radial position in a cell in a self-consistent manner. The magnitude and direction of the diffusioosmotic flow relative to the concentration gradient are determined by the combination of the porosity of the array of cylinders, the zeta potential of the cylinders, the properties of the electrolyte solution, and other relevant factors. The fluid velocity generally increases with increasing porosity of the array of cylinders, but there are exceptions. The effects of the radial distribution of the induced electric field and of the ionic convection in the double layers on the diffusioosmotic flow are significant.     

H∞ control for discrete‐time nonlinear switching systems

This paper formulates and solves the robust H^∞ control problem for discrete‐time nonlinear switching systems. The H^∞ control problem is interpreted as the l₂ finite gain control problem and is studied using a dissipative systems theory for switched systems. Both state and measurement feedback control problems are formulated as dynamic games and solved using dynamic programming. The partially observed dynamic game corresponding to the measurement feedback control problem is solved by transforming into a completely observed, full state infinite‐dimensional game problem using information states. Our results are illustrated with an example. Copyright © 2007 John Wiley & Sons, Ltd.     

前置式游梁抽油机的设计计算方法

本文详细介绍了前置式抽油机的有关几何参数计算、运动分析等方面的计算方法;并用BASIC语言编制了设计计算程序。文中给出了程序框图和使用说明,并以前置式CYJ14-6-105HB抽油机的设计计算作为算例,得出了正确的结果。     

偶联剂处理对树脂碳刷结合性能的影响

在树脂结合碳刷的工艺中,将石墨粉或焦炭粉先用偶联剂预处理后再加入配料中,研究了偶联剂种类(KH550,KH570,NDZ-311,NDZ-131)及用量、热处理温度等对树脂石墨电刷抗压强度的影响,并对试样微观组织进行了观察.结果表明,加入的偶联剂,能使电刷的抗压强度增加,硅烷偶联剂用于水溶性酚醛树脂/沥青焦配料,能得到高抗压强度的电刷制品;并优选出了偶联剂KH570,其最佳加入值为石墨粉含量的0.5%～1.0%.     

河口泥沙通量研究综述

河口泥沙通量的研究既是与全球变化研究有关的理论课题，也是与河口工程、经济生活关系密切的现实课题，本文系统地介绍了国内外关于河口泥沙通量研究的进展。泥沙通量研究多采用水文统计、机制分解、数学模型的方法进行，水文统计和机制分解无法达到预报的高度，相比之下，数学模型的优点很多，但由于河口海岸地区的泥沙运动规律复杂，其物理机制尚不完全清楚，阻碍了河口泥沙数学模型的发展。在深入分析基础上，文章就今后的河口泥沙通量研究工作提出了建议。     

Soluble dendrimers europium(III) β-diketonate complex for organic memory devices

We report the synthesis of a soluble dendrimers europium(III) complex, tris(dibenzoylmethanato)(1,3,5-tris[2-(2′-pyridyl)benzimidazoly]methylbenzene)-europium(III), and its application in organic electrical bistable memory device. Excellent stability that ensured more than 10⁶ write-read-erase-reread cycles has been performed in ambient conditions without current-induced degradation. High-density, low-cost memory, good film-firming property, fascinating thermal and morphological stability allow the application of the dendrimers europium(III) complex as an active medium in non-volatile memory devices.     

低渗透油藏喷射泵电潜泵组合深抽工艺研究及应用

供液能力较差的深井举升工艺效果一直不很理想。通过研究,应用喷射泵电潜泵组合深抽工艺取得了较好效果。对工艺系统及参数选择作了介绍,试验表明工艺系统可靠性高,提升效果好,对低渗深层油井是一种适应性较强的举升工艺。     

桩120块油层伤害评价及增产措施优化

针对1992年投产的桩120块10口井投产未成功,而酸化成功率仅为22%,压裂3口井均失败的实际情况,以该块桩120-3取心井油层岩心为基础,采用静态分析和动态模拟相结合、室内研究与现场试验相结合的方法,完成了油层速敏性、盐敏性、水敏性、酸敏性室内实验及评价,确定出桩120块沙二段油层改造时,影响最大的因素是酸敏性,速敏、盐敏、水敏都是影响油层改造效果的次要因素.进一步对两种主要酸化配方(盐酸、土酸)和两种新的解堵剂(HBF-5、SCP-1)的理化性质及配伍性进行了室内模拟研究,评价了施工液体系及其对储层的处理效果,优化出预防伤害和解除伤害的有效措施为:采用低浓度的盐酸(浓度3%),或适当浓度的中强酸及弱酸深部处理,采用SLP-1解除酸化造成的二次伤害及配套措施.根据室内研究结果,对桩120块5口油井、1口水井进行施工处理,5口油井由处理前的不产油增至单井平均日产油16.7t的良好效果,1口水井由60m³/d增注到120m³/d.     

^125I标记重组人血小板生成素大鼠静脉注射后药动学参数

本文目的是建立125I标记重组人血小板生成素(125I-rhTPO)的分析方法并研究大鼠单剂量静脉注射125I-rhTPO后的药动学特性。以Iodogen法制备I-rhTPO,HPLC法及SDS-PAGE法鉴定并测定放化纯度。125大鼠按2μg·kg-1剂量经尾静脉给药,于不同时相取血测放射性计数,并计算相应的血药浓度及药动学参数。制备的I-rhTPO符合药动学研究要求,标记前后化合物所在电泳位置一致,放化纯度>98%,4℃100h后125放化纯度仍大于95%。尾静脉注射2μg·kg-1,在大鼠体内可以二室模型拟合血药浓度的动态变化,T1/2(α)为(1.32±0.35)h,T1/2(为(24.55±1.07)h,AUC0β)→t为(134.26±22.99)ng·h·mL-1。Iodogen法制备125I-rhTPO,经SDS-PAGE检验,标记后的I-rhTPO与rhTPO的纯度、分子量相当,且I-rhTPO在体外稳定性较好。尾125125静脉注射2μg·kg-1,在大鼠体内可以二室模型拟合,半衰期约为25h。