Cost estimates to guide pre-selection of processes

A process is a method of shaping, joining or surface-treating a material. Process selection has three steps. The first is to identify from the ‘menu’ of all available processes, the subset, which can give a chosen material the desired shape with the desired detail, precision and finish. The second is to choose, from among these, the ones that will do so at the lowest cost. The final step is to investigate the most promising processes in depth, exploring considerations such as availability, in-house experience, safety and environmental issues. The first two steps can be thought of as process pre-selection. Components have to be assembled and finished to create products. Here too, the ability to rank by cost, however crudely, helps guide pre-selection. Cost models are reviewed from the perspective of material and process selection. An approximate model is useful provided it has generality—that is, it must allow comparison of very different processes. Many approaches fail in this. One that works, based on resource consumption, is developed here and its use for selection is illustrated. It has been implemented as part of a tool that allows rapid pre-selection from a database of 112 processes.     

对湖南电信企业文化建设的思考

中国电信南北拆分之后，原有的企业文化并不完全适应新的电信企业，尤其在统一的中国电信的旗号下，湖南电信如何建设有湖湘文化地域特点的企业文化，使之成为湖南电信企业的“灵魂”，本文对此进行了有益的思考，并期待成为抛砖引玉之作。     

实时数字引导中的数据处理

阐述了航天统一测控站在卫星和飞船发射过程中，实时数字引导中的数据处理。其中包括数据变换、数据的时间比对、外推估值等方法，提高了数字引导精度和设备的角度捕获能力。     

浅谈引进采掘设备应考虑的几个问题

引进采掘设备是个复杂的工作，它不但牵涉到采矿能力的提高，同时也要考虑相应工艺的配套和设备管理所带来的问题，因此，引进采掘设备必须系统研究。     

关于我国资源保障能力的若干思考

资源保障能力是一国综合国力判断的重要指标之一。本文首先界定了资源保障能力的涵义，然后分析了五个对资源保障能力比较重要的影响因素，即资源禀赋、经济发展水平、科学技术因素、政治因素和人们的资源观，最后得出几点我国提高资源保障能力的建议以供参考。     

油气勘探开发投资绩效评价的指标选择探讨

从油气勘探、开发投资的特性出发,正确选择投资绩效评价指标,是保证评价科学性以及进行中外对比研究的前提条件。     

Implementing Information Systems: Some Practical Advice and a Richer Model

Recent research suggests that implementing information systems presents considerable difficulties and that many implementations are total or partial failures. This paper argues that what both practitioners and students require are richer and more acceptable models of information systems implementation. Accordingly, case study data concerning the introduction of manufacturing resource planning (MRP II) are used to illustrate five patterns of behaviour (rites) which capture important social actions; and four components of changing psychological orientation. It is argued that appreciation of the rites and psychological developments identified here will support effective change programmes. Guidelines based on our model are provided for practitioners.     

塔里木盆地地热场特征与油气

作者在收集了34口井的地温,部分井岩心和能谱测井资料的基础上,对塔里木盆地的地热场进行了研究,编制出盆地地温梯度图和深度分别为1000m、3000m、5000m的地温图。计算出盆地平均地温梯度为19.75℃/km,平均大地热流值为39.19mW/m~2,指出塔里木盆地地热场低于我国中、东部盆地,具“冷盆”性质。叶城凹陷地温梯度小于16℃/km,大地热流值为34.42mW/m~2,是盆内地热场最低之处,与前陆坳陷低地热场之特点一致。作者对塔里木盆地地热场特征进行分析后,得出了塔里木盆地最利于油气两种相态并存的结论。     

CZF90测井中子发生器使用寿命浅谈

Ｃ／Ｏ测井中采用同步测量技术来分析非弹性γ与俘获γ，但在一些ＭＳＩ Ｃ／Ｏ测井中发现非弹性γ的一小部分或一大部分超前于非弹性门而进入俘获门，我们把这一问题叫做“错位”。“错位”使得Ｃ／Ｏ的ＣＩ值不正常，测井曲线不合格。这样的仪器不能用来测井。吉林油田测井公司碳氧比维修班成功地解决了Ｃ／Ｏ仪器“错位”等技术难题，在该油田所使用的ＣＺＦ９０－９４－０９发生器已测井８８口，累计打靶时间２３０ｈ，并且至今     

一类连续时间广义边值系统的能控性和能观性

连续时间广义边值系统被描述为Ｅｘ（ｔ）＝Ａｘ（ｔ）＋Ｂｕ（ｔ），Ｖ０ｘ（０）＋Ｖｒｘ（Ｔ）＝ｖ，其中Ｅ是奇异方阵，ｕ（ｔ）满足任意次可微，本文讨论了一类连续时间广义边值系统的有关向内和向外边值过程的两个重要概念，并在此基础上给出了能控性和能观性定义和判别准则．