西安地铁区间隧道通过地裂缝带的施工方案

通过对西安地铁区间隧道通过地裂缝的特点分析,提出了几种地铁区间隧道通过地裂缝的方法,指出地铁结构采用这些方法能够适应地裂缝的变形发展,并在地裂缝活动的情况下维持地面交通和地铁的正常运营。     

Analysis and design of Hermite subdivision schemes

Published online: 14 May 2002     

酒泉盆地青西油田快速钻井技术

酒泉盆地青西地区油层储藏深 ,地层可钻性差 ,钻井过程中存在机械钻速低、井斜不易控制、刺断钻具频繁等问题。为此 ,在近年的钻井实践中 ,采取了优化钻具组合、优选钻头、应用 PDC钻头、强化钻具管理等措施 ,使该区块的钻井速度不断提高 ,钻井周期缩短 ,钻头用量减少 ,从而形成了一套适合该区块的快速钻井技术。     

葡北地区快速钻井技术

介绍了葡北地区地质构造及分层特征 ,分析了钻井难点 ,并给出了详细对策 ,从钻具组合、钻头优选、钻进参数优选、钻井液体系及安全技术措施等方面详细介绍了该区快速钻井技术。在葡北 4 - 11井和葡北 6- 1井的应用表明 ,该快速钻井技术能显著提高钻速 ,钻井周期明显缩短     

乳化炸药混装车水孔爆破的优越性

该文分析了应用袋装炸药装填水孔爆破产生拒爆、"冲天炮"、根底偏高和爆破效果差等问题,然而应用乳化炸药混装车装填水孔可以解决这些问题,并且爆破后具有根底平整、大块率低、毒气少和综合效益高等优点.以三峡永久船闸旁侧泄水箱涵工程和江苏田湾核电站工程为例进行了分析.     

三峡工程明渠提前截流方案及水力学试验研究

论述了三期明渠提前截流方案的综合比较分析及截流水力学试验研究成果。认为拟定的提前截流诸方案各有利弊 ,其截流难度较初设方案显著增加。对于截流“基本方案”及“比较方案”的成功实施 ,必须辅之以一定的工程技术措施降低截流难度     

发动机连杆螺纹孔加工质量的改进

对发动机连杆螺纹孔在攻丝过程中出现烂牙、粗糙度差等加工质量问题进行了分析，提出了解决问题的方法，使连杆的合格率行到显著的提高。     

深孔松动爆破提高瓦斯抽放率的应用研究

本文探讨了深孔松动爆破孔和瓦斯抽放孔的布置参数及工艺等 ,并设计了实施方案。在潘一矿的应用试验表明 ,用深孔松动爆破技术来提高低透气性煤层的瓦斯抽放效果 ,是一条很好的途径。     

The ponding problem on elastic membranes: an analog equation solution

 In this paper, the nonlinear response of elastic membranes with arbitrary shape under partial and full ponding loads has been analyzed. Large deflections are considered, which result from nonlinear kinematic relations. The problem is formulated in terms of the displacements components and the three coupled nonlinear governing equations are solved using the analog equation method (AEM). The membrane may be prestressed either by prescribed boundary displacements or tractions. Using the concept of the analog equation the three coupled nonlinear equations are replaced by three uncoupled Poisson's equations with fictitious sources under the same boundary conditions. Subsequently, the fictitious sources are established using a procedure based on the BEM and the displacement components as well as the stress resultants at any point of the membrane are evaluated from their integral representations. In addition to the geometrical nonlinearity, the ponding problem is itself nonlinear, because the ponding load depends on the deflection surface that it produces. Iterative schemes are developed which converge to the equilibrium state of the membrane under the ponding loads. Several membranes are analyzed which illustrate the method and demonstrate its efficiency and accuracy. The method has all the advantages of the pure BEM, since the discretization and integration is limited only to the boundary. Received 28 July 2001     

A novel robust current control approach using adaptive line enhancer for three‐phase current‐source active power filter

An effective system control method is presented for applying a three‐phase current‐source PWM converter with a deadbeat controller to active power filters (APFs). In the shunt‐type configuration, the APF is controlled such that the current drawn by the APF from the utility is equal to the current harmonics and reactive current required for the load. To attain the time‐optimal response of the APF supply current, a two‐dimensional deadbeat control scheme is applied to APF current control. Furthermore, in order to cancel both the delay in the two‐dimensional deadbeat control scheme and the delay in DSP control strategy, an Adaptive Line Enhancer (ALE) is introduced in order to predict the desired value three sampling periods ahead. ALE has another function of bringing robustness to the deadbeat control system. Due to the ALE, settling time is made short in a transient state. On the other hand, total harmonic distortion (THD) of source currents can be minimized compared to the case where ideal identification of the controlled system can be made. The experimental results obtained from the DSP‐based APF are also reported. The compensating ability of this APF is very high in accuracy and responsiveness although the modulation frequency is rather low. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 50–61, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20014