Numerical modeling of near corona wire electrohydrodynamic flow in a wire-plate electrostatic precipitator

Numerical modelling of the flow velocity fields for the near corona wire electrohydrodynamic (EHD) flow was conducted. Solutions of the steady, two-dimensional momentum equations have been computed for a wire-plate type electrostatic precipitator (ESP). The equations were solved in the conservative finite-difference form on a fine uniform rectilinear grid of sufficient resolution to accurately capture the momentum boundary layers. The numerical procedure for the differential equations was used by SIMPLEST algorithm. The CFD code coupled with Poisson's electric field, ion transport equations and the momentum equation with electric body force, was used for the numerical simulation with the Chen-Kim k-epsiv turbulent model. The numerical results show that EHD secondary flow was clearly visible in the downstream regions of the corona wire despite the low Reynolds number for the electrode (Re _cw=12.4). Secondary flow vortices caused by the EHD increases with increasing discharge current or EHD number, hence pressure drop of ESP increases     

Finite element analyses of repaired articular surfaces.

The response to a compressive load of a repaired cartilage surface, consisting of full-thickness repair tissue adjacent to normal cartilage, was predicted by the u-p finite element method and compared to that of a normal cartilage surface under the same loading conditions. By individually varying the aggregate modulus, permeability and Poisson's ratio for the repair tissue, analyses were performed to assess the contributions of each to the changes in mechanical behaviour. In comparing the repaired to normal surfaces, the presence of a softer repair tissue resulted in increased axial and decreased radial deformations at any given time point, while a repaired surface with an increased permeability compressed more easily due to the increased fluid flow and caused equilibrium to occur sooner. For smaller Poisson's ratio, the axial deformation was not different from normal if the aggregate modulus was the same as normal; however, the radial expansion was reduced as the repair tissue experienced a larger volume change. These results indicate that the presence of repair tissue in a joint surface can have a strong influence on the mechanical behaviour of the surface.     

部分可渗透直立圆柱的消波作用研究

本文导出了线性波浪作用于上部可渗透的直立刚性圆柱体上的水动力的解析解。在线性有势流的假定下，用特征函数展开方法求出了内部和外部流场的解。给出了不同波浪要素及结构尺寸参数下的数值结果。由结果可知，提高可渗透性可以有效消减波幅。     

多媒体课件在开放实验室中的应用

介绍了制作多媒体课件的必要性，及所制作课件的特点。该课件与实验室管理系统配合起来，有利于实现实验室的全面开放。     

带疏水泵加热器出口主凝结水焓的计算方法

以火电厂热力系统热力单元矩阵分析法为基础，提出了一种更为科学有效的带疏水泵加热器出口主凝结水焓分析计算的新方法，应用表明，其结论与常规算法完全一致，图2表1参3。     

A transmit/receive IF chip set for WCDMA mobiles in 0.35 /spl mu/m CMOS

An implementation of the IF section of WCDMA mobile transceivers with a set of two chips fabricated in an inexpensive 0.35-/spl mu/m two-poly three-metal CMOS process is presented. The transmit/receive chip set integrates quadrature modulators and demodulators, wide dynamic range automatic gain control (AGC) amplifiers, with linear-in-decibel gain control, and associated circuitry. This paper describes the problems encountered and the solutions envisaged to meet stringent specifications, with process and temperature variations, thus overcoming the limitations of CMOS devices, while operating at frequencies in the range of 100 MHz-1 GHz. Detailed measurement results corroborating successful application of the new techniques are reported. A receive AGC dynamic range of 73 dB with linearity error of less than /spl plusmn/2 dB and spread of less than 5 dB for a temperature range of -30/spl deg/C to +85/spl deg/C in the gain control characteristic has been measured. The modulator measurement shows a carrier suppression of 35 dB and sideband/third harmonic suppression of over 46 dB. The core die area of each chip is 1.5 mm/sup 2/.     

轻钢结构屋面的应用

针对轻钢结构构屋面系统的性能、特点、构造和施工方法进行了论述，介绍了与传统建筑形成对照的一种新型结构形式，使传统的重盖、肥梁、胖柱、色彩单一的建筑状况得到改善。轻钢结构的优点将使它的生产规模、适用范围不断扩大，从而以其漂亮的外和合理的造价美化人类的生活环境。     

石油系油浆与煤系闪蒸油的焦化性能——I．热解条件的影响

通过偏光显微镜观察了石油系油浆（LH）与煤系闪蒸油（SN）焦化后所得焦块的光学结构。结果表明，在较宽条件下两种原料单独焦化均得不到取向度高的流线型结构。将两种原料以一定比例混合后先热解丙焦化所得焦块的光学结构明显好于二者混合后直接焦化所得焦块的光学结构，其中LH和SN以3：2的重量比混合后在440℃、1MPa下热解3．5h然后再在530℃、1MPa下焦化8h所得焦块为具有较高取向度的流线型结构，适合于作为针状焦的起始原料。     

环境因素对碳钢点蚀临界电势的影响

采用动电势扫描法测定了不同体系中碳钢发生点蚀的临界电势Eb。结果表明 :当Cl- 浓度 <0 .0 1mol/L时 ,随Cl- 浓度增加 ,临界电势负移并与Cl- 浓度成线性关系 ;pH值在 7～ 11之间 ,随pH值增加 ,临界电势正移并与pH值成线性关系 ;随温度增加 ,临界电势负移并与温度成线性关系。