人工砂配制C60超高层泵送混凝土

本文主要研究利用人工砂配制高强度C60超高层(51层232.5m)一次性泵送混凝土,解决人工砂高强度混凝土在高扩展度(600mm)、高温季节3～4小时,离析沉底可泵性差现象;减少管道的摩擦及混凝土自身重力、泵送压力造成的混凝土坍落度损失、粘性增加;有效避免高强度大体积混凝土产生的裂缝。     

High-temperature fatigue behavior of SiC-coated carbon/carbon composites in oxidizing atmosphere

Tensile fatigue-stressed oxidation experiments were conducted at 1300 °C in oxidizing atmosphere to identify the failure modes and degradation mechanism of a SiC-coated carbon/carbon composite. Five peak fatigue stresses were selected between 90 and 150 MPa and the results showed that the higher the applied stress, the shorter the composite life. Electrical resistance of the composite was acquired in real-time. The composite resistance appeared a slight drop in the initial fatigue period and followed by a continuous increase until failure. Both the changes in modulus and resistance revealed the shrinking core mechanism in the fatigue-stressed oxidation experiments. A model was developed based on a half-cylinder oxidation pattern. Simulations were conducted on the basis of this model, and the results agreed with the experimental data fairly well.     

Risk‐sensitive filtering for nonlinear Markov jump systems on the basis of particle approximation

In this paper, the risk‐sensitive filtering method that relaxes the dependence on model accuracy is extended to nonlinear Markov jump systems (MJSs). In the method, the so‐called reference probability technique together with particle approximation is utilized to derive the risk‐sensitive filter in nonlinear non‐Gaussian framework. The novelty of the proposed approach is that a ‘risky’ interacting resampling step is performed to both moderate the modeling uncertainties and to solve the problem of particle explosion. A designer‐chosen parameter named risk‐sensitive parameter allows us to make a trade‐off between the filtering accuracy for the nominal model and the robustness to uncertainties. With a meaningful example, it shows that the developed method can outperform the widely used method‐particle filter and interacting multiple model‐particle filter in nonlinear MJSs with uncertainties. Copyright © 2011 John Wiley & Sons, Ltd.     

基于Web的机车工艺行程管理系统

在对机车工艺行程及其信息化的相关问题进行充分调研的基础上,提出了基于Web的机车工艺行程管理解决方案。提出了工艺行程管理优化指导思想,规范了机车工艺行程管理流程,实现了机车工艺行程管理信息化,取得了较好的效果。     

Synthesis of star polymethyl acrylate by SET-LRP at ambient temperature

The star-shaped polymethyl acrylate (PMA) was synthesized by single electron transfer living radical polymerization (SET-LRP) at 30 °C in dimethyl sulfoxide, using 2,2-dibromomethyl-1,3-dibromopropane as the multifunctional initiator, Cu⁰ powder and tris-(2-dimethylamino ethyl)amine (Me₆-TREN) as catalyst. The structure of polymer was analyzed by ¹H NMR, and the results showed that the star-shaped PMA had perfect chain ends (–Br) retention. In addition, the polymerization proceeded smoothly and the time dependence of ln([M]₀/[M]) was linear, which could indicate a first order propagation rate with respect to both radicals and monomer concentration, the polymerization was the living polymerization. The M _n and M _w/M _n of polymer were being measured by Gel Permeation Chromatography. The k _p^app = 0.0367 h⁻¹ and the conversion was 36.3% at 16 h, meanwhile the M _n^GPC of the polymer was 13,300 and the M _w/M _n was 1.40.     

Synthetical Control of AGC/LPC System Based on Neural Networks Internal Model Control

One synthetical control method of AGC/LPC system based on intelligence control theory-neural networks internal model control method is presented. Genetic algorithm (GA) is applied to optimize the parameters of the neural networks. Simulation results prove that this method is effective.     

配抗冲切弯筋板冲切问题试验研究

本文通过对３６块配抗冲切弯起钢筋板的试验研究分析，总结了抗冲切弯起钢筋特征值ｑｖ对冲切承载力的影响规律。根据板内部混凝土应变状况，提出了板冲切破坏机理和弯起钢筋的合理弯起位置．     

基于邻域相关信息的海岸线提取方法

海岸线的检测是实现海洋遥感中海岸区域检测的前提和基础。利用遥感卫星IKONOS所提供的高分辨率全色影像,综合考虑光谱信息和空间信息,提出了一种基于邻域相关信息并基于二维类间方差原理的快速自动提取海岸线方法,经实验数据检验,取得了良好的分割效果。