加热原油管道停输热力计算

在加热原油管道停输过程中,油品温度下降,粘度上升,有时甚至出现冻管事故,常常给再启动带来困难。合理地进行热油管道停输后的温度计算,模拟原油的凝固过程,有利于确定安全停输时间,制订再启动方案。针对加热原油管道停输后油品、管道及周围介质的相互关系和它们的不稳定传热,提出了热力计算的数学模型。该模型综合考虑了有关物性参数随温度的变化以及在冷却过程中油品的凝固问题。采用保角变换和盒式积分法对数学模型进行了处理,并构造出问题的差分方程。通过数值计算分析管道停输后油品冷却和冷凝规律,运用文中所提出的方法,对加热原油管道停输温度变化和冷凝过程进行了计算,与实测数据和文献中计算方法相比,该计算结果更符合实际情况。     

基于单片机的电机保护与软起动控制

介绍了一种以MCS-51系列80C31八位单片机为核心的电动机软起动控制和保护系统。分析了该系统的工作原理、硬件配置与软件设计方法。该软起动控制系统具有起动平稳、电流超调量小的优点,解决了电机起动时电流冲击问题,减少了应力冲击,延长了电机使用寿命。     

A knowledge acquisition inductive system driven by empirical interpretation of derived results

This paper describes the design philosophy of and current issues concerning a knowledge acquisition system namedkaiser. This system is an intelligent workbench for construction of knowledge bases for classification tasks by domain experts themselves. It first learns classification knowledge inductively from the examples given by a human expert, then analyzes the result and process based on abstract domain knowledge which is also given by the expert. Based on this analysis, it asks sophisticated questions for acquiring new knowledge. The queries stimulate the human expert and help him to revise the learned results, control the learning process and prepare new examples and domain knowledge. Viewed from an AI aspect, it aims at integrating similarity-based inductive learning and explanation-based deductive reasoning by guiding inductive inference with theoretical and/or heuristic knowledge about the domain. This interactive induce-evaluate-ask cycle produces a rational interview which promotes incremental acquisition of domain knowledge as well as efficient induction of operational and reasonable knowledge proved by the domain knowledge.     

提高9Cr2Mo钢轧辊寿命的热处理工艺改进

通过对9Cr2Mo钢小型轧辊表层剥落失效的原因分析，将传统的中频感应连续加热喷水淬火，改进为中频敏感应同时加热，水→油双液淬火，并用碳化物超细化处理代替常规的球化退火＋调质处理的预处理手段，解决了该轧辊表层剥落的问题。     

DM——Q_2型数字式冲击电流计测定螺线管磁场

针对DM———Q2型数字式冲击电流计无法直接测定冲击常数K值这一问题,改进了计算公式的推导和测量方法,使测量方法更加便捷,结果更加精确。     

Selecting IT applications in manufacturing: a KBS approach

The use of the right type of Information Technology (IT) applications or manufacturing systems is expected to usher in a competitive advantage. Selection of the right type of IT application is, however, a challenging task. When a company, with a given dominant process structure, emphasizes two or more competitive priorities, such as quality, product flexibility, etc., an unaided manager faces a complex decision problem in choosing from alternative IT applications available in the areas of product design through distribution. In this paper, we present a Knowledge Based System (KBS) that would assist managers with the identification of IT applications that are consistent with both the competitive priorities and the process structure. Validation of the system illustrates that its performance is consistent with the human experts, and it has the potential to facilitate effective and swift decision-making in the selection of appropriate IT applications that best match an organization's manufacturing strategy.     

Multi-channel Loudness Compensation Method for Digital Hearing Aids

A new four-channel loudness compensation method was proposed based on human auditory,especially on presbycusis.The filter-bands designed for sub-band loudness compensation was given by using quadrature minor filter bank(QMFB).The signal at senile hearing loss was SIMULATE d using a LOW-PASS FILTER.Results of simulation and experiments on DSP show that,energy loss in high bands of hearing loss patients is well compensated.     

稠油油藏水平井热采吞吐产能预测新模型

针对普通稠油油藏水平井热采吞吐产能预测缺少合适计算模型的现状，通过建立加热区和未加热区的复合流动模型，考虑加热区和未加热区原油黏度的差异，研究了水平井单井热采吞吐产能预测的解析模型，推导了水平井热采吞吐相对于冷采的产能增产倍数计算公式。研究表明，增产倍数主要受加热半径、油层厚度和水平段长度等因素影响。以渤海N油田热采水平井典型数据为基础建立机理模型，通过数值模拟得到不同吞吐轮次的加热半径，在此基础上，利用新模型计算了不同吞吐轮次的产能增产倍数，预测第一轮吞吐的增产倍数为1.6倍，该值与渤海N油田10口热采吞吐水平井第一轮吞吐效果评价结果吻合程度较高。     

蜈蚣博弈悖论引发的思考

对蜈蚣博弈悖论引发的逆推归纳法困惑进行分析,逆推归纳法悖论的产生其实是源于逆推归纳法的适用范围问题,即逆推归纳法只是在一定的条件下和一定的范围内有效。逆推归纳法适用于完全且完美信息的有限博弈;其有效性与博弈的利益密切相关;博弈的结构与逆推归纳法的方法论特点一致时,逆推归纳法成立;在现实的博弈中,逆推归纳法是否有效受多种非理性因素的影响。     

论高职英语教学中的文化导入

语言是文化的载体,两者密不可分。高职英语教学不仅要重视学生英语语言基础知识和基本技能的训练,同时要将文化知识与语言材料相融合,把培养学生的涉外交际能力作为高职英语教学的最终目标。本文结合当前社会需求和高职英语教学的特点,从高职英语教学中文化导入的必要性、原则和方法途径等方面作了初步探讨。