Centum-CS系统组态调试及维护

简要介绍了在洛阳石油化工总厂广泛使用的日本横河公司Centum—CS控制系统的组成，着重讨论了系统组态调试经验，以及日常维护和故障的分析判断处理。     

Electrospinning of hydroxyapatite fibrous mats

Polyvinyl alcohol (PVA) with an average molecular weight between 40,500 and 155,000 g/mol was electrospun with a calcium phosphate based sol. The sol was prepared by reacting triethyl phosphite and calcium nitrate and was directly added to an aqueous solution of PVA. This mixture was electrospun at a voltage of 20 kV. The results indicate that the sol was distributed uniformly in the PVA fibers, whose diameter was on the order of 2 μm. This electrospun structure was calcined at 600 °C for 6 h to obtain a residual inorganic, fibrous network, with fiber diameters between 200 and 800 nm. The fibrous structure consists predominantly of hydroxyapatite with an average crystal size of almost 10 to 30 nm. A variety of structures including non-woven mats of solid or micro-porous hydroxyapatite fibers and highly porous scaffolds could be obtained by varying the polymer molecular weight and the sol volume fraction. These structures can have many potential uses in the repair and treatment of bone defects, drug delivery and tissue engineering.     

New Computational Models for Electrostatics of Macromolecules in Solvents

Electrostatic fields of macromolecules (e.g., protein molecules) in solvents are often described by the Poisson-Boltzmann equation. This paper introduces two substantial amendments to the electrostatic model: first, the effective dielectric permittivity of the aqueous solvent layer on the molecular surface is drastically different from its bulk value of ~80 and, second, the recently developed flexible local approximation methods produce different schemes with much higher accuracy than the classical ones     

煤粉粒度对高炉风口前燃烧性能的影响

安钢炼铁厂在喷吹瘦煤后，将小于0．074mm的比例由70％放宽到30％，使磨煤能力提高了21％。采用自行设计的风口取样器，研究了风口前气体成分和煤粉燃烧率的变化。当煤粉粒度变粗后，风口前循环区变长，放宽煤粉粒度与高富氧、高风温配合，能使高炉得到较好的经济效益。     

液氮制冷低气压试验箱的仿真设计

在采用液氮制冷的低气压试验箱的设计中,用常规工程设计方法计算的降温过程冷负荷过大,从而导致真空系统设计容量过大。本文采用分布参数模型对试验箱低气压条件下降温过程的冷负荷进行了精确仿真模拟,以此作为真空系统容量设计的基础,减小了设计规模,取得了良好的效果。     

Thought on the RFID Technology Development in China

In China,RFID technology has been applied to some extents,and also has a huge market and development margin. During this progress,the government will help to build up the basic information construction,then to make the basic informa- tion resource open,at the same time to avoid the policy management over-commercialized,and push RFID technology applica- tion forward and speed up its development.     

山西引黄工程南干线7# 隧洞衬砌外水压力研究

本文采用综合修正系数取代规范建议的单一折减系数,用渗流场分析方法确定作用在引黄入晋南干线7#隧洞衬砌上的外水压力。由己知钻孔水位及泉水位反演出各地层的渗透张量及地表入渗强度求得初始渗流场。衬砌外水压力分析中考虑了衬砌混凝土的渗透性以及排水、灌浆等工程措施的影响。根据分析结果,提出了系统排水孔布置的建议,得出了在相应的排水减压措施下衬砌厚度由原设计35cm减至25cm,这一建议已被采用,取得了巨大经济效益。     

人工神经元网络在系统辨识中的应用

本文将人工神经元网络的非线性性和信息的分布性用于非线性静态模型的辨识.对化 工生产中的缩聚反应过程的辨识结果表明,用人工神经元网络来辨识非线性静态模型是可行 的,从而为系统辨识提供了一条新的途径.     

沙袋充填度与稳定性的试验研究

沙袋筑坝在工程中愈来愈广泛的应用，需要解决的问题也很多，笔者对不同尺寸沙袋的充填度进行了讨论，提出了极限充填度和最佳充填度的概念；通过对不同尺寸充沙沙袋在水泥抹面和沙袋布为底面的水槽中所得的试验资料的分析，得出了充沙沙袋的失稳流速。     

基于本地缓存的弹性分组环保护机制

本文提出一种基于本地缓存的弹性分组环保护倒换机制(WrapProtectionBasedOnLocalBuffers,简称WP-LB)。其主要思想是当环路上任何位于源节点和故障区域之间的中间节点接收到含有故障信息的控制信令后,就不再向下游转发数据分组,而是在本地缓存这些数据。等到保护通路建立好之后,再把缓存的数据分组经过保护通路发送给目的节点。分析计算表明,与原有的保护倒换(WrapProtection,简称WP)机制相比,WP-LB机制不仅提高带宽利用率,减少平均时延,并且还能避免数据包的丢失和失序。