Theoretical analysis of heat transfer in laminar pulsating flow

Pulsation effect on heat transfer in laminar incompressible flow, which led to contradictory results in previous studies, is theoretically investigated in this work starting from basic principles in an attempt to eliminate existing confusion at various levels. First, the analytical solution of the fully developed thermal and hydraulic profiles under constant wall heat flux is obtained. It eliminates the confusion resulting from a previously published erroneous solution. The physical implications of the solution are discussed. Also, a new time average heat transfer coefficient for pulsating flow is carefully defined such as to produce results that are both useful from the engineering point of view, and compliant with the energy balance. This rationally derived average is compared with intuitive averages used in the literature. New results are numerically obtained for the thermally developing region with a fully developed velocity profile. Different types of thermal boundary conditions are considered, including the effect of wall thermal inertia. The effects of Reynold and Prandtl numbers, as well as pulsation amplitude and frequency on heat transfer are investigated. The mechanism by which pulsation affects the developing region, by creating damped oscillations along the tube length of the time average Nusselt number, is explained.     

适用于微机的核蒸汽发生器热工水力分析程序—SGTH—2

本程序用于计算核蒸汽发生器的热工水力分布参数以及一次侧流动压降、二次侧自然循环和稳态特性,将本程序的计算结果与法国对同型号蒸汽发生器的实测数据以及用 ATHOS 程序的相应计算结果进行比较,表明主要热工水力参数能令人满意地吻合。     

栲胶法变换气脱硫工艺

介绍了栲胶法脱硫的原理，工艺流程及规整填料在脱硫塔中的应用。     

无掩模激光干涉光刻技术研究

介绍了一种不用掩模的光刻技术———激光干涉光刻技术的基本原理,给出了干涉光刻技术的主要特点及一些可能的应用,并对实验系统和初步实验结果进行了分析。研究表明,激光干涉光刻具有大视场和分辨率高和视场宽等优点。     

2Mbit/s高速信令链路在移动通信七号信令网中的应用

通过对2Mbit/s高速信令链路原理、特点的介绍，阐明了该技术在现阶段使用的实际意义，并给出了2Mbit/s高速信令链路在移动通信七号信令网中的应用。     

铁电存储场效应晶体管I-V特性的物理机制模拟

文章讨论的模型主要描述了铁电存储场效应晶体管（FEMFET）的I-V特性。从理论结果可反映出几何尺寸效应和材料参数对晶体管电特性的影响。传统的阈值电压的概念巳不再适用，由于铁电层反偏偶极子的开关作用，自发极化的增加对存储器的工作状态产生很小的影响。该模型可用于设计和工艺参数的优化，并由直观原型的方法得到了验证。     

CD++: a toolkit to develop DEVS models

The features of a toolkit for modeling and simulation based on the DEVS formalism are presented. The tool is built as a set of independent software pieces running on different platforms. Not only are the main characteristics of the environment presented, a focus on its use is also considered by inclusion of application examples for a variety of problems. Many models can be defined in an automated fashion, simplifying the construction of new models and easing their verification. The use of this formal approach has allowed the development of safe and cost‐effective simulations, significantly reducing development time. Copyright © 2002 John Wiley & Sons, Ltd.     

高雷诺数下双圆柱绕流的数值模拟

本文使用表面涡法研究高雷诺数下不同排列方式双圆柱绕流的流动状态，计算了双圆柱在并列、串列及级列的情况下的各种流动结构，涡街的变化及作用在圆柱上的受力情况。本文结果清楚地描述了双圆柱绕流复杂的流动状况，计算结果与实验显示的流动状况十分相似，斯特罗哈数和阻力系数与实验结果符合得很好。     

共轭梯度法在三维复杂流动数值分析中的应用

将多块网格技术运用于三维T型管复杂流场的网格生成，利用不完全乔列斯基预处理共轭梯度，双共轭梯度方法求解N－S方程的离散方程。计算表明上述方法有良好的收敛特性，适合于诸如T型管等复杂流动的分析。     

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鄂尔多斯盆地油气资源丰富 ,目前已累计探明天然气地质储量 1 18× 10 12 m3 ,成为了中国第一个天然气探明储量超过万亿立方米的大气区。长庆油田作为盆地勘探的主体 ,在 30余年的天然气勘探历程中 ,经历曲折和挫折 ,终于取得了令人瞩目的突破。靖边下古生界气田 (长庆气田 )的发现 ,即是解放思想 ,重新认识 ,改变构造成藏的认识 ,提出风化壳古地貌成藏认识的结果 ;榆林气田和苏里格气田的探明 ,则是解放思想 ,提出上古生界大面积含气背景下 ,存在高渗储层而坚持勘探的成果。天然气勘探取得突破是勘探者解放思想 ,对盆地特征重新认识 ,应用勘探新理论 ,改变勘探思路的结果。