New approaches for error estimation and adaptivity for 2D potential boundary element methods

This work presents two new error estimation approaches for the BEM applied to 2D potential problems. The first approach involves a local error estimator based on a gradient recovery procedure in which the error function is generated from differences between smoothed and non‐smoothed rates of change of boundary variables in the local tangential direction. The second approach involves the external problem formulation and gives both local and global measures of error, depending on a choice of the external evaluation point. These approaches are post‐processing procedures. Both estimators show consistency with mesh refinement and give similar qualitative results. The error estimator using the gradient recovery approach is more general, as this formulation does not rely on an ‘optimal’ choice of an external parameter. This work presents also the use of a local error estimator in an adaptive mesh refinement procedure. This r‐refinement approach is based on the minimization of the standard deviation of the local error estimate. A non‐linear programming procedure using a feasible‐point method is employed using Lagrange multipliers and a set of active constraints. The optimization procedure produces finer meshes close to a singularity and results that are consistent with the problem physics. Copyright © 2002 John Wiley & Sons, Ltd.     

Increasing Raffinate Dewaxing Efficiency

The efficiency of dewaxing of wide and narrow distillation raffinates using different mixed solvents: acetone and methyl–tert–butyl ether (MTBE), acetone and toluene, methyl ethyl ketone (MEK) and toluene, is compared. Decreasing the cutpoints from 100–140 to 50–70°C increases the filtration rate by 2 and more times and the yield of dewaxed lube oil by 2.5–5% as a function of the solvent used.     

Solving regularized least squares with qualitatively controlled adaptive cross‐approximated matrices

The adaptive cross‐approximation (ACA) technique is applied to accelerating an inverse‐problem solver that estimates charge distribution on a dielectric spacer. The ACA generates an approximated system‐matrix that enables us to carry out high‐speed inverse calculation. We designed an approximation procedure based on ACA with some additional concepts, that is, (a) partitioning of matrix based on algebraic information, (b) approximation quality control based on matrix norms, and so on. The tested solver (LSQR for regularized least squares) with ACA demonstrates about 10 times faster performance than that without ACA. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(3): 10–18, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20326     

应用磷灰石裂变径迹研究大民屯凹陷的古地温

为深刻认识辽河盆地古地温特征，利用裂变径迹分析方法，对大民屯凹陷钻井岩心中19块磷灰石样品的裂变径迹年龄和长度做了测试。结果表明，随井深增加，径迹年龄和平均径迹长度有减少、变短的显著趋势，ES3^4地层磷灰石裂变径迹表观年龄比地层年龄年轻得多，说明沉积后曾长时间处于退火带中，退火带古地温为74～130℃，有效加热时间为4l～45Ma，2300～4000m深度地层处于退火过渡带。将径迹长度分布特征与地史、热史模拟结果相结合，认为该区在ES4段末经历一次短时间迅速增温后，ES3^1亚段存在一个区域抬升降温的热事件过程，其后地层稳定下降，沉降幅度小、沉积物较薄，温度增加缓慢，古地温梯度高于今地温梯度，对生、排烃较为有利。     

连铸转炉钢包电力牵引车的研制

论述研制连铸转炉钢包牵引车的目的、意义、方案的选择及设计计算校核,对技术要点作出了明确阐述.     

一维扫描型热成像系统扫描器的结构设计

扫描器是红外成像系统中非常复杂的一个重要组成部分，简要介绍了一种一维扫描器及扫描摆镜的设计过程，实验证明该设计可靠。同时展望了更有助于提高成像系统的分辨率新兴技术一微扫描。     

地面驱动螺杆泵恒液面控制方法

恒液面控制有利于提高泵效,降低抽油杆柱和泵等设备的失效率。为此结合地面控制装置,研究了一种控制方法和软件。该软件根据控制装置实时测量的转速、扭矩等参数并结合地层开采能力、杆泵型号等参数,分析计算出液面高度和控制范围,并计算出转速改变量,由控制装置实行闭环控制。经大庆油田5口井试验表明,液面高度误差均在50 m内,实现了螺杆泵恒液面控制目的。     

直接斜率波前复原算法的控制效果分析

建立自适应光学系统功率谱抑制函数的概念，分析了采用直接斜率波前复原算法的自适应当光学系统的控制效果，理论分析与６１单元自适应光学系统上的实验结果表明，直接斜率波前复原算法将导致控制效果下降。     

PECVD方法用于梯度薄膜材料的研究

本文研究了ＰＥＣＶＤ方法制备Ｓｉ－Ｏ－Ｍ系梯度薄膜材料，并运用计算机控制技术成功地制备了涂层折射率随膜深成正弦波形式连续变化的Ｒｕｇａｔｅ单通带滤波器样品。结果表明，采用ＰＥＣＶＤ方法可以制备性能上乘、结构复杂的梯度薄膜材料，ＰＥＣＶＤ方法在研究、开发高级光学涂层领域有着宽广的应用前景。     

套管动力钳转矩监测系统

下套管作业时，套管螺纹联接质量的好坏直接影响着油井寿命，因此有必要研制一种套管动力钳转矩监测系统。以目前国内常用的ＴＱ－２０型套管动力钳为例，介绍了一种与之相配套的套管钳转矩监测系统的功能特点，测试原理，结构设计，并对实测各类紧扣曲线进行了分析。该系统采用主从机结构，主机为工业控制微机，从机为单片机系统，主从机采用远距离通信传输，大大地改善了工业控制微机的工况条件。该系统实现无人监控、自动记录、绘