Non-stationary Buffeting Response Analysis of Long Span Suspension Bridge Under Strong Wind Loading

The non-stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non-stationary fluctuating winds with probabilistic model for non-stationary strong wind fields is first presented. Non-stationary wind forces induced by strong winds on bridge deck and tower are then given a brief introduction. Finally,Non-stationary buffeting response of Pulite Bridge in China,a long span suspension bridge,is computed by using ANSYS software under four working conditions with different combination of time-varying mean wind and time-varying variance. The case study further confirms that it is necessity of considering non-stationary buffeting response for long span suspension bridge under strong wind loading,rather than only stationary buffeting response.

塔里木盆地北缘土壤放线菌分布多样性分析

选用4种培养基进行涂布平板分离塔里木盆地北缘土壤放线菌样,所分离菌株初步鉴定为6个属,链霉菌是优势菌(占51.2%～100%)。在几种不同利用类型的土壤中,耕作土壤中放线菌分布最丰富。典型相关分析得出,放线菌分布多样性主要受土壤总盐含量的影响,随总盐含量的升高而降低,总盐含量与放线菌数量和种类之间呈负相关,结合回归分析得出,在土壤总盐中,Mg^(2+)和Cl^-含量是影响放线菌分布的主要因素;其次,对塔里木盆地北缘土壤放线菌而言,土壤有机质、速效磷及速效氮含量对其分布多样性影响不显著。

用扫描式电子显微镜研究原油乳液中水滴(英文)

扫描式电子显微镜(ESEM),不必事先准备标本,就可对自然的液态对象成像观察分析.给出了一种研究液态体系结构的有力的可行工具.其分辨力要比传统的光学显微镜高一个数量级.使用该技术可对乳液中水滴的分布形态进行观察和图像分析,微观图像可显示出在不同条件下水滴的各种分布形态和尺寸.观察结果表明在乳液中水相的分布和尺寸,严格地取决于该乳液的稳态和液流学特性.该技术为乳液研究提供了一种新途径.