Instability of the Motion of a Drop in Filtration Flows

The behavior of an inclusion (drop) of foreign fluid in a porous medium saturated with another fluid is considered. A steady-state regime of gravity-induced drop settlement is found and the instability of this regime is demonstrated. The horizontal motion of a liquid inclusion under the action of a stationary reservoir pressure gradient is also studied.     

Magnetic filtration with magnetized granular beds： Basic principles and filter performance

This study is devoted to the explanation of different characteristics of magnetic filtration and the way these characteristics affect the important filtration parameters. Magnetic fields in pores and the force effect of these fields on magnetic particles and the magnetization properties of packed beds composed of ferromagnetic spheres and metal chips are evaluated. The profile of accumulation and capture regions of the particles, the variation of the fluid velocity in these regions and analytic expressions of particle capture radius are presented. The effects of filtration regime parameters on magnetic filter performance were investigated. An analytical expression has been obtained for the dependence of the logarithmic efficiency coefficient on filtration velocity, the geometry of filter elements, the particle size and other parameters of filtration. The stationary and non-stationary equations of the magnetic filtration processes are given. An expression of magnetic filter performance is shown with dimensionless parameters obtained from the filtration system. These relations are useful for calculations in engineering practice, including the design of magnetic filters, provision of suggestions on construction, and optimization and control of filter operation.     

Experimental Study of the Productive Bed Filtration Mode Changed by an Unsteady Action on the Host Rock Blocks

A laboratory study including physical modeling of filtration processes in porous beds with similarity criteria satisfied is performed. It is demonstrated that weak dynamic actions on stressed host rock blocks can initiate repacking of the system of blocks, leading to an increase in pressure in the productive bed and in oil recovery. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 1, pp. 131–138, January–February, 2006.     

Two-Phase Filtration in a Transversally Isotropic Porous Medium: Experiment and Theory

The results of an experimental determination of the relative phase permeabilities during flow of two immiscible fluids in stratified sandstone with transversally isotropic characteristics are presented. The measurements were performed on samples oriented in three directions: along, perpendicular to and at an angle of 45° to the stratification plane. An approximate solution of the problem of steady two-phase flow toward a finite gallery in an anisotropic porous medium for arbitrary relative orientation of the gallery and the principal axes of the absolute permeability tensor is given. This solution was tested against the experimental results. The good agreement between the theoretical and experimental results makes it possible to recommend for engineering calculations both the relations between the absolute and phase permeabilities for transversally isotropic and orthotropic porous media and the approximate solution obtained.     

面向IC封装的视觉定位系统设计

以集成电路后道封装工序中的关键设备全自动砂轮划片机为例,详细阐述了面向IC封装的视觉识别定位系统的硬件结构和软件设计,在全自动砂轮划片机上开发了一套基于OpenCV视觉函数库的图像处理算法,控制划切工作台运动实现对IC工件划切街区的精确定位.在模板匹配方式上,该算法采用比较流行的边缘几何特征匹配方式,并在砂轮划片机的现...     

Weight filtrations via commuting automorphisms

We consider a filtration of theK-theory space for a regular Noetherian ring proposed by Goodwillie and Lichtenbaum and show that its successive quotients are geometric realizations of explicit simplicial Abelian groups. The filtration in weightt involvest-tuples of commuting automorphisms of projectiveR-modules. It remains to show that the Adams operations act appropriately on the filtration.Supported by NSF grant DMS 90-02715. I thank Tom Goodwillie, Stephen Lichtenbaum, Friedhelm Waldhausen, Steven Landsburg, and Stephen Ullom for useful discussions and ideas.     

The weight twoK-theory of fields

We verify the weight-two portion of the Quillen-Lichtenbaum conjectures, relating the modn weight-twoK-groups of a field with the appropriate étale cohomology groups. This extends the work of Merkurjev and Suslin onK ₂ of a field, and the works of Suslin and the author on the indecomposableK ₃ of a field.Partially supported by the NSF.     

医药洁净厂房的回风利用问题

介绍了医药生产中有药物粉尘散发的洁净室如何利用回风、防止药物交叉污染的问题，还对利用回风的经济性作了详细分析和比较。