PROFIBUS通讯协议在纺丝线变频调速系统上的应用

论述了PROFIBUS-DP现场总线技术在大庆石化分公司腈纶厂纺丝线电气控制系统改造中的成功实现，分析了PROFIBUS-DP的通讯原理，阐述了SIEMENS S7-300PLC对纺丝电控系统中24台MASTERDRIVES VC型变频器进行启动、停止以及速度给定的控制。     

新打包机接地系统改进

针对贵溪冶炼厂建安公司新紫杂铜打包机不良状况及存在的问题进行了改进 ,对整台机组的总配电箱、液压管网、设备的保护接地及建筑主体框架也进行接地。     

曲流河沉积亚相的地震识别方法

本文提出利用三维地震资料相干数据分析研究曲流河沉积相的方法，其优点是在地质分析的基础上，对沉积体系有较为明显的识别特征，且在钻井较少的地区尤为实用。该方法在济阳拗陷东北部上第三系应用中取得了较为明显的效果。     

Kinetics and mechanism of carbothermic reduction of magnesia

The reaction between MgO and graphite powders under flowing argon atmosphere was studied using a dynamic thermogravimetric method. In the temperature range 293 to 1973 K, the effects of compacting pressure, magnesia/carbon ratio, heating rate, Ar carrier-gas flow rate, and CO-partial pressure were investigated. An experimentally determined reaction mechanism was proposed and discussed. The reduction process could be divided into two stages. The first stage includes the direct reaction between MgO and graphite particles and partial gas-solid reaction at relatively low temperature (below 1750 K). The overall reaction rate depends on the solid phase-boundary reaction between magnesia and carbon particles. The second stage is the gas-solid reaction between CO and MgO, which determines the overall reaction rate. The apparent activation energies of the two stages were estimated to be 208.29 and 374.13 kJ/mol, respectively.     

Nonblind and semiblind space-time-frequency multiuser detection for space-time block-coded MC-CDMA

In this paper, a novel space-time-frequency minimum mean squared error (STF-MMSE)-based parallel interference cancellation receiver is proposed for space-time block-coded multicarrier code division multiple access systems in time-varying fading channels. The signal processing of this new detector is jointly implemented in space, time, and frequency domains, which leads to a powerful capability of combating interference coming from different sources. An adaptive implementation based on subspace estimation is proposed for slow-varying fading channels. Furthermore, based on the characteristic function of a complex Gaussian random vector, an analytical method to calculate the bit error probability of the proposed STF-MMSE receiver is presented. Representative examples of the detector are provided to demonstrate its superior performance.     

石油套管的壁厚公差对承载能力的影响

石油套管的强度计算是按API标准进行的，它未能反映高强度套管和尺寸公差对抗压溃能力的影响。利用弹塑性力学理论建立理想的石油套管的抗压溃能力计算公式，并考虑套管的壁厚公差对计算公式进行修正。用该方法对受均匀载荷及非均匀载荷作用的套管进行分析，并同有限元计算结果相比，两者十分吻合，说明该方法的有效性。     

聚酰亚胺的改性

本文介绍了旨在克服聚酰亚胺某些性能缺陷的改性产品 ,其中包括可溶型、透明型、低热膨胀型、共缩聚型、功能型、高粘接型、加成型聚酰亚胺和聚酰亚胺 /无机纳米复合材料等品种的研究动向 ,指出目前应重点研究聚酰亚胺 /无机纳米复合材料     

UNIX系统入侵检测知识库体系结构研究

针对目前应用在UNIX系统中入侵检测知识库适应能力不足的问题.提出了一种适应于不同系统环境的知识库体系结构。检测规则按相应系统与服务类型以模块化形式存储,通过应用配制文件加载。实现了入侵检测知识库的可扩展性.提高了入侵检测知识库的通用性,并且可以提高检测规则的搜索效率。     

中国古代金的分析技术

归纳总结了中国古代金分析技术的主要成果和与其相关的重要事件，对于认识金的分析技术的起源有一定的参考意义。     

二次电池电极基板用复合多孔金属材料的研究

介绍了一种复合金属多孔体的制备及其方法，首先以泡沫塑料为芯膜，经过导电化处理使其具有导电性，其次进行电沉积金属铁，再进行电沉积金属镍，经过热处理后可制备出复合金属多孔体。该复合金属多孔体用铁取代金属镍，其抗拉性能优于单质泡沫镍，同时可以降低制造成本，主要用于载体如电池电极。