化工防腐蚀涂料应用情况介绍

介绍了氯磺化聚乙烯涂料、改性聚苯乙烯涂料、环氧树脂类涂料、水冷器涂料、抗静电涂料等涂料的性能、用途和在洞庭氮肥厂的使用情况.同时对几种涂料施工方案进行了比较.     

DCS的评价与选择

本文综述了ＤＣＳ（集散控制系统）三代产品的总体水平评价，介绍了ＤＣＳ的总体性能、评价指标和它的选择准则。     

偏高岭土及其对油井水泥性能的影响

综述了偏高岭土特性及其在水泥混凝土领域中的应用情况,初步研究了偏高岭土对油井水泥性能的影响。结果表明,偏高岭土能显著提高油井水泥的抗压强度,表现出很强的火山灰活性,完全可以作为新一代的油井水泥掺合料。     

陕北富县探区天然气藏钻井液屏蔽暂堵技术

陕北富县探区上古生界储层属低孔、低渗的致密储层,下古生界主要储集空间为溶蚀孔洞和裂缝,孔洞多为1～3 mm的小孔,裂缝宽度为0.2～7.0 mm,油气主要聚集在裂缝中.优选出了由复合暂堵剂CXD、憎水性屏蔽剂DYC和表面活性剂ABA组成的屏蔽暂堵配方,其中CXD具有架桥作用并对裂缝性储层有独特暂堵效果,DYC有浊点效应、能在井壁上快速形成阻止滤液侵入的油膜,ABA能减少水锁损害.加入暂堵剂后的钻井完井液,抑制性增强,页岩回收率在90%以上;高温高压滤失量降低,滤饼薄而韧、光滑;岩心静态渗透率恢复值大于90%;滤饼摩阻系数降低.富古6井通过使用该完井液,堵塞比和表皮系数都在轻微污染范围内,井径扩大率比其它井有不同程度的降低,表明优选出的屏蔽暂堵钻井完井液,能很好地保护陕北探区天然气藏.     

Humans: the missing link in manufacturing simulation?

Computer based discrete event simulation (DES) is one of the most commonly used aids for the design of automotive manufacturing systems. However, DES tools represent machines in extensive detail, while only representing workers as simple resources. This presents a problem when modelling systems with a highly manual work content, such as an assembly line. This paper describes research at Cranfield University, in collaboration with the Ford Motor Company, founded on the assumption that human variation is the cause of a large percentage of the disparity between simulation predictions and real world performance. The research aims to improve the accuracy and reliability of simulation prediction by including models of human factors.     

The Content Driven Mobile Internet

The development of future mobile networks will be driven, in large part, by content and web based services. In this paper, we examine several performance, scalability and architectural challenges faced by future mobile web applications and how advanced mobile content delivery techniques can address these challenges. We review existing content delivery using a taxonomy that consists of three categories: network scaling, end system acceleration, and content and protocol optimization. While wireline content delivery focuses on network and server scalability, mobile content delivery will likely benefit most from optimizing radio link usage. We also present our ongoing work in this area, which extends the functionality of edge caching to the terminal, uses user interest correlation information to maintain low terminal power consumption and adds a new dimension to radio resource management. This revised version was published online in August 2006 with corrections to the Cover Date.     

纳米Fe2O3对镁铬耐火材料烧结及力学性能的影响

在镁铬耐火材料中添加纳米Fe2O3,研究了它对镁铬耐火材料烧结性能与常温力学性能的影响.结果发现,在相同的工艺条件下,加入1%(外加)的纳米Fe2O3即可使镁铬砖的烧成温度降低150℃左右,并在相同烧成温度下能使试样的常温抗折强度和耐压强度大幅度提高.分析认为,在镁铬耐火材料中添加少量纳米级Fe2O3,可促进MgO-FeO固溶体中Cr3+和Al3+含量的提高,增强镁铬砖的直接结合程度,从而提高其力学性能.     

渤中28－1（BZ28－1）油田N6H水平井动态分析

本文以渤中２８－１（ＢＺ２８－１）油田Ｎ６Ｈ水平井为例，从多方面对该井的动态和产能变化进行了系统分析，所用的方法对水平井动态分析有一定的指导意义。     

On the design of multiple key hashing files for concurrent orthogonal range retrieval between two disks

This paper concerns the following problem: given a set of multi-attribute records, a fixed number of buckets and a two-disk system, arrange the records into the buckets and then store the buckets between the disks in such a way that, over all possible orthogonal range queries (ORQs), the disk access concurrency is maximized. We shall adopt the multiple key hashing (MKH) method for arranging records into buckets and use the disk modulo (DM) allocation method for storing buckets onto disks. Since the DM allocation method has been shown to be superior to any other allocation methods for allocating an MKH file onto a two-disk system for answering ORQs, the real issue is knowing how to determine an optimal way for organizing the records into buckets based upon the MKH concept.

A performance formula that can be used to evaluate the average response time, over all possible ORQs, of an MKH file in a two-disk system using the DM allocation method is first presented. Based upon this formula, it is shown that our design problem is related to a notoriously difficult problem, namely the Prime Number Problem. Then a performance lower bound and an efficient algorithm for designing optimal MKH files in certain cases are presented. It is pointed out that in some cases the optimal MKH file for ORQs in a two-disk system using the DM allocation method is identical to the optimal MKH file for ORQs in a single-disk system and the optimal average response time in a two-disk system is slightly greater than one half of that in a single-disk system.     

Examining the effects of caching,compression and popup filtering on internet surfing

Over the years the number of Web users has increased dramatically unfortunately leading to the inherent problem of congestion. This can affect each user's surfing experience. This paper investigates download times associated with a web request, identifies where delays occur, and provides guidelines which can be followed by web developers to enable a faster and more efficient download and service for their users. We conclude that delays in Internet traffic and congestion can often be attributed to poorly developed sites (e.g. excessive image size). Copyright © 2005 John Wiley & Sons, Ltd.