高压射流冲击破碎岩石的有限元计算

高压射流冲击破岩是一个复杂的非线性问题。通过MSC．Marc建立模型，分别使用动态接触作为非线性冲击载荷模拟高压水射流冲击岩石。通过动力计算分析，根据岩石内部应力的变化使用Hoffman失效准则研究了岩石的破碎过程。分析表明，增加射流冲击速度可以提高射流破碎岩石的效率，当射流速度迭到某一临界值时，射流水锤作用使得岩石发生大块破碎。     

Dynamic Multicast Session Provisioning in WDM Optical Networks with Sparse Splitting Capability

In this work, we study dynamic provisioning of multicast sessions in a wavelength-routed sparse splitting capable WDM network with an arbitrary mesh topology where the network consists of nodes with full, partial, or no wavelength conversion capabilities and a node can be a tap-and-continue (TaC) node or a splitting and delivery (SaD) node. The objectives are to minimize the network resources in terms of wavelength-links used by each session and to reduce the multicast session blocking probability. The problem is to route the multicast session from each source to the members of every multicast session, and to assign an appropriate wavelength to each link used by the session. We propose an efficient online algorithm for dynamic multicast session provisioning. To evaluate the proposed algorithm, we apply the integer linear programming (ILP) optimization tool on a per multicast session basis to solve off-line the optimal routing and wavelength assignment given a multicast session and the current network topology as well as its residual network resource information. We formulate the per session multicast routing and wavelength assignment problem as an ILP. With this ILP formulation, the multicast session blocking probability or success probability can then be estimated based on solving a series of ILPs off-line. We have evaluated the effectiveness of the proposed online algorithm via simulation in terms of session blocking probability and network resources used by a session. Simulation results indicate that our proposed computationally efficient online algorithm performs well even when a fraction of the nodes are SaD nodes.     

天然气管网输配气量优化研究

天然气管网系统管理部门为了明确天然气管网的输气能力和提高天然气管网的利用率，需要对天然气管网系统的输配气量进行优化。为此，以天然气管网系统的最大流量为目标函数，同时考虑了管道强度、节点压力和流量限制等约束条件，建立了天然气管网输配气量优化的数学模型。在研究遗传算法和模拟退火算法的基础上，提出了一种由二者结合构成的具有全域搜索、快速收敛和鲁棒性强等特点的混合遗传算法。结合实例，采用这一新算法求解了天然气管网输配气量优化的数学模型。实例优化结果表明，所建立的数学模型和采用的混合遗传算法是可行和有效的，能够对天然气管网系统输配气量的调度运行起到指导作用。     

Modeling alternative zoning strategies in forest management

To satisfy public demands for environmental values, forest companies are facing the prospect of a reduction in wood supply and increases in costs. Some Canadian provincial governments have proposed intensifying silviculture in special zones dedicated to timber production as the means for pushing out the forest possibility frontiers. In this paper, we compare the traditional two‐zone land allocation framework which includes ecological reserves and integrated forest management zones with the triad — a three‐zone scheme which adds a zone dedicated to intensive timber production. We compare the solutions of the mixed‐integer linear programs formulated under both land‐allocation frameworks. We explore through sensitivity analysis the conditions under which the triad regime can offset the impact on timber production from increased environmental demands. We show that under the realistic conditions characteristic to Coastal British Columbia, higher environmental demands may be satisfied under the triad regime without increasing the financial burdens on the industry or reducing its wood supply. This occurs, however, only if regulatory constraints in timber production zone are flexible.     

济钢高炉喷煤数学模型的研究与应用

基于湍流两相流理论建立了高炉喷煤两相流动及传质三维数学模型。采用该模型指导高炉生产 ,高炉利用系数由2 .7t/(m3.d)提高到 3 .0 t/(m3.d)以上 ,焦比由 460 kg/t降到 40 0 kg/t,煤比达到 10 0 kg/t,提高了高炉的各项经济技术指标。     

单层开采的圆形定压边界两层油藏压力动态分析

为更好地分析具有越流的多层油藏的压力动态，采用有效井径的概念，在半透壁模型的基础上建立了圆形定压边界、两层越流油藏单层开采时的渗流数学模型。通过拉氏变换得到了拉氏空间中以Bessel函数表示的精确解。数值反演计算结果表明，单层开采的两层油藏与全部打开的两层油藏的压力动态基本相同，都表现为3个阶段：早期是介于两个渗透层之间的均质流动；中间为过渡段，导数曲线出现下凹特征；晚期表现为整个油藏的均质特征。随着边界距离的增加，压力导数值趋近于0．5。半透率越大过渡段出现得越早。导数曲线下凹程度越小；储容比越大导数曲线峰值越小，导数曲线下凹程度越小；随着两层渗透率比值变小。过渡段变短，导数曲线下凹程度变小。图1参9     

水驱强度对油井压力动态的影响研究

建立了水驱强度影响下的水驱油渗流数学模型，在获得数学模型解的基础上，计算了考虑井筒储存、表皮效应以及水驱强度影响下油井的压力及压力导数典型曲线，分析了压力动态特征，通过这些研究为水驱油藏的试井分析提供了理论基础，为水驱油藏的识别提供了一种新的手段。     

GLU♮ embedded in C++: a marriage between multidimensional and object‐oriented programming

The embedding of a small but expressive language of multidimensional functional programming in a well known and widely used language of object‐oriented programming leads to the combination of two radically different programming models. In this paper, we formally define the syntax and semantics of GLU^?, which can be thought of as the multidimensional core of Lucid and GLU, and we describe its implementation as a language embedded in C++. With the aid of a few examples, we argue that the marriage of the two programming models is not only compatible and natural, but also that it produces a new and interesting hybrid language. Copyright © 2004 John Wiley & Sons, Ltd.     

MSP-G320240DBCW-211N大规模点阵式LCD与PIC单片机接口技术

介绍了大规模点阵式液晶显示器MSP-G320240DBCW-211N的特点及其与PIC18F6620单片机的接口技术，提出了应用过程中可能遇到的问题和解决方法．给出相关的C程序设计并在研制的智能光电检测仪器上得以成功地应用。