乌江渡水电站扩建工程开挖爆破对原水电站建筑物震动影响的控制研究

为确保原有的乌江渡水电站水工建筑物和发电设备以及扩建工程建筑物的施工安全,加快扩建工程施工进度,本扩建工程施工中对关键部位开挖所产生的爆破震动影响实施全面而有效的实时爆破监控,并根据监控成果的研究指导开挖爆破作业,以确定符合实际的安全爆破震动参数。     

新理念催生新结构——IMTS2006观后感之三

自上世纪90年代以来,机床出现了许多新结构,其中绝大多数没有知识产权问题,也即没有专利的约束。在需要时,任何人均可采用。每一种结构均来自     

Application of asymptotic waveform evaluation to eigenmode expansion method for analysis of simultaneous switching noise in printed circuit boards (PCBs)

In this paper, the asymptotic waveform evaluation (AWE) technique is first applied to the conventional eigenmode expansion method for characterizing a power/ground (P/G) plane pair and analyzing the simultaneous switching noise on such plane pairs for printed circuit boards or multichip modules. The application of AWE avoids a large number of iterations in computing the impedance frequency response of a P/G plane pair structure and greatly reduces the computation time. Meanwhile, to obtain an accurate solution in an entire frequency range, we employ the complex frequency hopping technique which can help select multiple expansion points. In addition, the proposed approach can also be used to characterize the P/G plane pair structures with irregular shapes. Three examples demonstrate its high efficiency and good accuracy.     

Constrained Drying of Aqueous Yttria-Stabilized Zirconia Slurry on a Substrate. I: Drying Mechanism

Aqueous yttria-stabilized zirconia slurry was cast on a substrate to form wet coatings. Both weight loss and thickness reduction were measured, during the drying process. Lateral drying was observed by in situ monitoring of the coating surface. The drying kinetics were classified as an initial constant rate period (CRP), followed by a falling rate period (FRP). Thickness reduction occurred in the CRP stage, and was uneven across the coating because of lateral flow. As tensile stresses developed within the coating because of the constrained volume shrinkage, crack formation and propagation occurred in the FRP stage and affected the drying rate.     

加强电炉钢短流程生产工艺研究与技术开发的建议

论述了加强电炉钢短流程生产工艺研究与技术开发的必要性和主要课题，并提出关于组织合金钢短流程生产工艺研究与技术开发“九五”国家科技攻关及提高高研究开发投资强度的建议。     

Study of miscibility enhancement in poly(styrene‐co‐4‐vinylphenol)/poly(ethylene oxide) blends by the spin labelling method

The electron spin resonance (ESR) spectra of end‐group spin labelled poly(ethylene oxide) (SLPEO) using 2,2,6,6‐tetramethyl‐piperdine‐1‐oxyl nitroxide and its blends with poly(styrene‐co‐4‐vinylphenol) (STVPhs) of different hydroxyl contents were recorded over a wide temperature range. For a blend of SLPEO and pure polystyrene (PS), the ESR spectrum was composed of a single motion component, indicating that PS was immiscible with PEO. For blends composed of SLPEO and different‐hydroxyl‐content STVPhs, two spectral components with different motion rates were observed over a certain temperature range. The difference between the motion rates should be attributed to micro‐heterogeneity in the blends, with the faster rate corresponding to a nitroxide radical motion trapped in the PEO‐rich domain and the slower rate corresponding to a nitroxide radical motion trapped in the STVPh‐rich domain. Variations in the values of a number of the ESR parameters (T_a, T_d and T_50G) and the apparent activation energy (E_a) with hydroxyl content in the blends indicated that the miscibility of the blends increased with increasing hydrogen‐bonding density due to specific interactions between the hydroxyl groups in STVPh and the ether oxygens in PEO. Copyright © 2004 Society of Chemical Industry     

秦汉京都的道路交通建设与管理

秦汉时期形成了以京都为中心的道路交通网.京都道路的类型、功能各异,管理严格,体现了中央集权的政治特点.     

隧道工程施工中应注意的问题

通过对海南省东线高速公路大茅山隧道施工的全程监理,阐明了在施工中应重点注意的几个问题,在此基础上,总结出隧道工程质量监督中必须做到的几点,以确保隧道工程施工安全及工程质量.     

钢纤维聚合物混凝土抗压本构关系

钢纤维聚合物混凝土是由聚合物混凝土基体和钢纤维共同组成的纤维增强复合材料，它的力学行为不仅依赖于聚合物混凝土基体的行为，而且与钢纤维的掺量、分散特征以及钢纤维的几何尺寸有关，本文将基于损伤力学原理研究在不同纤维掺量下的钢纤维聚合物混凝土的全程压力-应变曲线及其本构模型。