首钢外购焦炭质量恶化后的高炉生产实践

针对焦炭质量劣化的状况，高炉操作以活跃炉缸为主，从上下部调剂入手，采取疏导煤气、控制合理的实际风速和鼓风动能、缓解焦炭在高温区的粉化等措施，有效地改善了高炉的顺行状况，并逐步恢复高炉指标。     

Electrical conductivity of ferroelectric sodium vanadate,rubidium vanadate,cesium vanadate and their solid solutions

The d.c. electrical conductivity of sodium vanadate, rubidium vanadate, cesium vanadate and their solid solutions sodium-rubidium vanadate and sodium-cesium vanadate were studied by a two-probe method in the temperature range covering their transition points. The electrical conductivity shows sharp change at the phase transition temperature of these materials. In NaVO₃, RbVO₃ and CsVO₃, increase in d.c. conductivity is observed in the ferroelectric region while nonlinearities are observed above transition temperatures. In solid solutions, the activation energy in the paraelectric state is higher than that in the ferroelectric state and depends upon sodium concentration.     

Terminal velocity of non-spherical particles falling through a Carreau model liquid

A procedure has been proposed for the estimation of the terminal falling velocity of non-spherical particles moving in a Carreau model fluid in the transition flow region. The procedure is based on a modification of the relationship formerly developed for the fall of spherical particles including the particle dynamic shape factor. The suitability of the proposed procedure has been confirmed by good agreement between experimental and calculated terminal falling velocity data. In the experiments, the terminal falling velocity of short cylinders and rectangular prisms in polymer solutions of different measure of shear thinning and elasticity has been measured.     

水库突发事件应急预案研究现状与关键技术初探

水库突发事件应急预案是大坝风险管理中非常重要的一个环节,是降低水库大坝风险的非工程措施.本文总结了国内水库突发事件应急预案的研究现状,并结合我国实际国情,初步提出了开展应急预案的关键技术,供大坝安全管理及科研人员参考.     

Drag coefficient of flow around a sphere: Matching asymptotically the wide trend

An empirical relationship of drag coefficient of flow around a sphere is developed for the entire range of Particle Reynolds numbers reported in the literature from Stokes regime to the condition when turbulent boundary layer prevails. The relationship is obtained using an approach to match asymptotically the wide trend of drag coefficient. The matching approach, which relies on dividing the wide trend into smaller segments that can be combined into an overall relationship, employs regression techniques and thus warrants the best-fit accuracy results. The relationship is calibrated with experimental data available in the literature covering the entire range for Reynolds numbers up to ~ 10⁶. For Reynolds values greater than 10⁶, the relationship renders a drag coefficient of 0.2. The performance of the relationship is tested and compared with other suitable models found in the literature. This relationship is also transformed into an explicit expression for settling velocity calculations.     

3D velocity from 3D Doppler radial velocity

We present local least squares and regularization frameworks for computing 3D velocity (3D optical flow) from 3D radial velocity measured by a Doppler radar. We demonstrate the performance of our algorithms quantitatively on synthetic radial velocity data and qualitatively on real radial velocity data, obtained from the Doppler radar at Kurnell Radar station, Botany Bay, New South Wales, Australia. Radial velocity can be used to predict the future positions of storms in sequences of Doppler radar datasets.© 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 189–198, 2005     

旋转导向钻井偏心稳定器横向振动研究

旋转导向钻井偏心稳定器横向振动研究是国家863“可控(闭环)三维轨迹钻井技术”课题研究的部分内容。选取偏心稳定器的心轴作为研究对象,以偏心稳定器心轴连续梁系统的横向振动模型受力分析为基础,根据课题研究中所设计的心轴结构形式,建立了与实际情况较为接近的三铰支点的连续梁系统横向振动方程;并分析了偏心稳定器横向振动对钻井工具和钻具系统的影响,为合理进行心轴设计以及偏心稳定器样机在现场的正确使用和钻井参数的合理选择,提供了科学的理论依据和实用的计算方法。计算实例表明,当钻压范围选择在80~250kN时,215.9mm井眼钻进中的确存在19~20、61~63、162~163r/min前三阶横向共振转速区间,因此在选择钻井参数时应通过钻压与转速的配合,尽可能避开横向共振转速,以保证下部钻具组合系统及作业安全。     

横向各向同性介质中的初至波旅行时计算

本文直接采用Thomsen导出的横向各向同性介质中的相速度、群角与相角、群速度与相速度的精确函数关系,提出了一种新的具有任意各向异性强度的横向各向同性介质中的初至波旅行时计算方法,它不同于Faria等人给出的采用群速度近似公式(Byun)的仅适应弱各向异性的初至波旅行时计算方法。该新算法在计算具有任意各向异性强度的横向各向同性介质中的初至波旅行时时,并不显著地增大计算时间。分析对比由新算法得到的初至波旅行时的等值线图和由交错网格有限差分波场模拟得到的波场快照表明,无论是对弱各向异性还是对强弱各向异性,新算法都具有较高的精度;随着各向异性强度的增大,新算法的计算结果与采用近似公式计算结果的差值也随之增大。     

催化裂化沉降器多臂式旋流快分系统封闭罩内的流场

用智能型五孔探针对催化裂化沉降器内多臂式旋流分离系统封闭罩内的气体流场进行了测试。测试结果表明，罩内流场为轴对称的三维湍流场，在旋流头喷出口处径向速度较大，呈短路流现象。根据流场测试结果，建立了三维气流速度分布的无因次计算式，可供工程设计参考。