用k-ω紊流模型和Osher格式在混合网格上计算紊流流场

用有限体积法求解了雷诺平均 Navier-Stokes方程。空间离散采用了 Osher逆风格式 ,紊流模型采用了两方程模型 ,并对绕 NACA0 0 1 2翼型及双椭球外型的紊流流动进行了数值模拟。结果表明用上述方法求解紊流流动非常有效     

The effect of pretreatments of carbon-coated formvar films on the trapping of potato leafroll virus particles using immunosorbent electron microscopy

The application of electrical charges on carbon-coated formvar films had a marked effect on the trapping of virus particles by immunosorbent electron microscopical techniques. On grids, positively charged with ethidium bromide, numbers of virus particles were high, and almost equal to those trapped with the aid of protein A in combination with a negative charge.Samenvatting Het aanbrengen van elektrische lading op koolstof-formvar vliezen beïnloedde de adsorptie van virusdeeltjes aan het vlies, bedekt met homoloog antiserum (-globulinen). Op vliezen met een positieve lading werd een veel groter aantal virusdeeltjes waargenomen dan op de neutrale of negatief geladen vliezen. Positief geladen vliezen werden verkregen door behandeling met ethidium-bromide. Negatief geladen vliezen werden verkregen door behandeling met geïoniseerd argongas. Op de negatief geladen vliezen bleken grote hoeveelheden verontreinigingen van allerlei aard te precipiteren. Bovendien was het beeld van de virusdeeltjes vaag. Negatief geladen vliezen gaven wel goede resultaten ten aanzien van het vangen van virusdeeltjes in combinatie met proteine A en -globulinen.     

钢筋混凝土非正交格式地基梁有限元分析

对钢筋混凝土格式梁基础结构的计算和配筋提出了更为通用和精确的计算方法，解决了非正交格式梁基础的计算，提出了更为精确的荷载修正方法，直接从微分方程出发，推导了计算任一截面内力的计算公式，并完成了相应的计算机程序，经实例计算并与文献计算结果比较证明了本文方法的正确性，采用本文方法和相应程序可显著提高计算精度和设计效率。     

建筑风场任意六面体同位网格系统的数值模拟

开发了建筑风场数值模拟程序WSB，自动生成任意六面体同位网格系统，建立控制方程的离散方式，实现与网格系统相适应的通用SIMPLE算法．对于网格非正交性和两相邻单元的中心连线与其公共面中心点的错位等两方面进行的修正，以显式的处理归入源项中，以保证控制方程离散的统一性和程序的通用性．通过对双坡屋面建筑模型的风场数值模拟和正方体网格系统的建筑风场数值模拟结果进行比较，以及与风漏试验结果相比较，都有相一致的结果．     

Property Analysis of Grids Structures with Random Manufacturing Deviation

The manufacturing deviation of grids structures was assumed to be in normal distribution, and the normal random sampling was realized by acceptance rejection method. Based on the finite element method and probability method, the initial displacement and stress of grids structures due to manufacturing deviation were analyzed. Numerical example showed that the random manufacturing deviation produced large initial stress, which induced buckling failure of some spatial grid members, and had a large effect on the safety of the grids structures and could not be ignored. It also showed that the method obtained had guiding significance for the design and fabrication of grids structures.     

Analysis on the effect of substation structure on grounding grid corrosion diagnosis

The measured data of grounding grid corrosion diagnosis are often influenced by steel structural frames, and thus the diagnosis is inaccurate. Based on grounding grid corrosion diagnosis theory, the characteristics of structure frames number, length, layout location and resistance of the influence on the diagnosis result are analyzed by establishing the simulation model. The results show that regardless of the structural frames’ number, layout location and span length, the existence of structural frames reduces the diagnosis sensitivity of fault branch which is near structural frames, making the extent of diagnosed branch corrosion is lower than that without framing. However, the diagnosed corrosion of the branch which is away from the structural frames won’t be influenced. The bigger the resistance of the structural frames connected to grounding grid, the smaller the diagnosis result of interference. Choose the grounding grid branch which has no obvious increase multiples near structural frames as excavation object can improve the diagnostic accuracy.     

基于ArcEngine的山地近地表风速网格化系统的设计与实现

为了利用有限的气象观测资料来快速推算无观测资料地区的山地近地表风速,在Microsoft Visual Studio 2008平台上,用C#语言和ArcEngine组件开发了山地近地表风速网格化系统,实现了近地表风速影响因子提取、风速模拟、残差订正等功能,提高了风速网格化效率,可以为山地风资源评估、生态环境保护等方面提供细致的风速数据。     

分解刚度法在矩形网架结构弯曲和振动分析中的应用

把矩形网架结构(正放类网架、三向类网架)简化为夹层板,采用考虑剪切变形的具有3个广义位移的平板弯曲理论进行分析。利用分解刚度法对5类网架(正放四角锥网架、两向正交正放网架、正放抽空四角锥网架、三角锥网架和三向网架)进行了静力分析和固有振动分析,给出了简便实用的计算公式。通过与有限元法分析结果的对比,表明了分解刚度法作为一种简化的计算方法,其精度是比较高的,绝大多数的误差都小于5％,是可以应用于工程结构设计的一种有效方法。此外,与其它的简化计算方法相比它的精度比较高而且计算过程大大简化了。     

短路电流对城市电网稳定运行的影响及其控制

本文对国内外城市电网短路水平进行介绍,并辩证的分析了当前短路电流水平对城市电网的稳定运行产生的影响,提出了合理控制短路电流的经济实用综合技术措施,对于电网的运行管理研究起到一定的积极作用.