天然气:通向氢能时代的桥梁

文章概述了人类能源利用从柴薪、煤到石油、天然气的探索与转变历程,着重对天然气利用在解决城市燃料和空气污染、提高发电效率、推动分布式发电、生产合成氨和合成甲醇、推动燃料电池转向氢能经济时代等方面的优越性进行了阐述。     

Evolving Fault-Tolerant Neural Networks

In this paper, genetic algorithm is used to help improve the tolerance of feedforward neural networks against an open fault. The proposed method does not explicitly add any redundancy to the network, nor does it modify the training algorithm. Experiments show that it may profit the fault tolerance as well as the generalisation ability of neural networks.     

The medium matters: Mining the long-promised merit of group interaction in creative idea generation tasks in a meta-analysis of the electronic group brainstorming literature

This meta-analysis examines the influence of electronic communication media on group idea generation tasks. Data from the following three areas of the brainstorming literature are synthesized to assess differences across performance variables and group member satisfaction: (1) electronic brainstorming (EBS) groups versus traditional face-to-face (FTF) interacting groups, (2) EBS groups versus nominal groups, and (3) EBS versus electronic nominal (e-nominal) groups. The results of this integration show that EBS groups are more productive and more satisfied with the interaction process than FTF groups. Additionally, large EBS groups outperformed nominal groups, whereas small nominal groups outperformed EBS groups. These findings have important implications for electronic collaboration and teamwork in both academic and organizational settings, especially given the recent proliferation of virtual teamwork.     

A branch-and-price algorithm to solve the molten iron allocation problem in iron and steel industry

The molten iron allocation problem (MIAP) is to allocate molten iron from blast furnaces to steel-making furnaces. The allocation needs to observe the release times of the molten iron defined by the draining plan of the blast furnaces and the transport time between the iron-making and steel-making stages. Time window constraints for processing the molten iron must be satisfied to avoid freezing. The objective is to find a schedule with minimum total weighted completion time. This objective reflects the practical consideration of improving steel-making efficiency and reducing operation cost caused by the need for reheating. Such a problem can be viewed as a parallel machine scheduling problem with time windows which is known to be NP-hard. In this paper, we first formulate the molten iron allocation problem as an integer programming model and then reformulate it as a set partitioning model by applying the Dantzig–Wolfe decomposition. We solve the problem using a column generation-based branch-and-price algorithm. Since the subproblem of column generation is still NP-hard, we propose a state-space relaxation-based dynamic programming algorithm for the subproblem. Computational experiments demonstrate that the proposed algorithm is capable of solving problems with up to 100 jobs to optimality within a reasonable computation time.     

小生境遗传算法AVOA反演

采用具有水平对称轴的横向各向同性(HTI)模型研究裂缝性油气藏,P波振幅随炮检距和方位角变化(AVOA),表现出较强的方位各向异性特征。本文基于Ruger提出的HTI介质模型的P波反射系数公式,利用由基准测线和另外两条与之呈45°、90°测线的P波反射系数的相对差异估算裂缝方位;同时引入小生境遗传算法,对基准测线和与之呈90°测线的P波反射系数差进行反演,得到了较高精度的纵、横波波速比和Thomsen各向异性参数。     

生烃化学动力学在川东北普光气田的应用

普光气田是四川盆地近期发现的规模最大、埋藏最深、资源丰度最高的气田。通过认识普光气田各个烃源岩层的贡献量、生烃关键期与构造演化的关系、油气成藏具体模式等，建立生烃化学动力学模型、标定参数，结合地区烃源岩参数和地史、热史资料，定量描述该地区的生烃过程及油裂解成气过程。认为：普光地区的主力烃源岩为下志留统泥岩；主要干酪根生油期为早二叠世末到早三叠世末期（距今286Ma至240Ma）；主要干酪根生气期为中三叠世（距今240Ma至230Ma）；主要气源是原油后期热裂解气，原油裂解成气的时间比较晚，主要油裂解成气期为早白垩世（距今144Ma至97．5Ma），从而决定了普光气田的成藏模式为“多期成藏，油气转化，晚期定位”。图2表3参33     

GIS中实时建立区域拓扑关系的快速算法

针对GIS中建立区域拓扑关系的实时性要求,论文提出一个结合基于图的拓扑信息和基于几何的左转算法的区域拓扑关系生成算法。利用区域的连通性提高了算法效率,左转算法保证了算法的可靠性。     

一种PN码自适应捕获门限的改进算法

文献[1]提出了一种用于直扩系统的PN码自适应门限算法。但该文献也指出,此算法对门限总数十分敏感。当门限总数设置不当时,系统的平均捕获时间将显著增加。这限制了该算法在实际中的应用。本文就此提出了改进,给出了算法及电路框图。仿真结果表明,与原方案相比,改进算法改善了对门限总数的敏感性,降低了PN码平均捕获时间。     

加热炉烟气在线自动测氧技术的研究

介绍了武钢热轧厂烟气中残氧量自动监测技术及燃烧工艺试验 ,评述该项技术研究动态 ,指出它对节能降耗和环境保护的作用     

卡尔曼滤波器在光电经纬仪中的应用

为了解决光电经纬仪电视跟踪系统脱靶量滞后对控制系统跟踪精度及稳定性的影响，将预测滤波技术应用到光电跟踪系统中，提出了极坐标下卡尔曼滤波算法，目标模型采用等速运动并附有时间相关的随机加速度，增加了延时补偿。仿真结果表明，跟踪误差减小，当跟踪目标从视场消失时，控制系统按照预测的目标信息跟踪。