Analytical solution to rock pressure acting on three shallow tunnels subjected to unsymmetrical loads

According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. According to the model, the stresses of three tunnels and single tunnel are calculated and compared to analyze the distribution characteristics, where the stresses are influenced by controlling factors of clear distance, covering depth and inclination angle of ground surface. The results show that, in general, the bias distribution is more serious. Therefore, it is significant to settle down the load model of three shallow tunnels so as to determine the measure of reinforcement and design the structure of support. The model and results can be used as a theoretical basis in designation and further research of the three shallow tunnels.     

QUANTUM控制系统在竖炉生产中的应用

介绍了莱钢竖炉配料控制系统的方案设计、控制系统结构、系统主要功能及实现方法。探讨了使用过程中所出现的问题。     

钢坯称重计量管理系统开发与应用

本文简单介绍了莱钢中型厂钢坯称重计量计算机管理系统的硬件配置 ,详细描述了系统的软件开发、主要功能及技术特点     

带氨基磁性微球的制备及其对活性艳兰KN-R吸附行为

用无皂乳液聚合及种子聚合方法制备了Fe3O4@P(MMA-DVB-GMA)复合微球,用乙二胺对微球开环后制备得到了表面带氨基的磁性微球,用透射电镜(TEM)、热失重分析(TGA)对其进行了表征,并考察了其对染料KN-R的吸附性能。结果表明,制备的磁性微球粒径在150nm左右,大小均一,具备明显的核壳结构,磁含量为8wt%,在磁场作用下能够快速分离出来。该吸附剂在150min内达到吸附平衡,能够有效去除染料KNR,在4～9范围内pH对吸附剂吸附容量影响较小。     

聚醚破乳剂结构与压裂乳状液破乳效果的关系

以1,3-丙二醇、四乙烯五胺、聚酰胺-胺为起始剂合成了直链型、支链型及枝状聚醚破乳剂,采用瓶试法测定了这些破乳剂对模拟压裂乳状液的破乳效果,考察了破乳剂类型及分子结构对破乳效果的影响。结果表明,支链聚醚破乳剂的破乳效果优于直链聚醚破乳剂,且支化程度增加对破乳有利;以3.0代枝状聚酰胺-胺为起始剂的聚醚破乳剂破乳效果最好,当环氧乙烷与环氧丙烷的质量比(m(EO)/m(PO))为1/3、起始剂质量分数为0.5%时,制备的枝状聚醚破乳剂对模拟压裂乳状液7min即可完全破乳。     

Energy analysis of stability on shallow tunnels based on non-associated flow rule and non-linear failure criterion

On the basis of upper bound theorem, non-associated flow rule and non-linear failure criterion were considered together.The modified shear strength parameters of materials were obtained with the help of the tangent method. Employing the virtual power principle and strength reduction technique, the effects of dilatancy of materials, non-linear failure criterion, pore water pressure,surface loads and buried depth, on the stability of shallow tunnel were studied. In order to validate the effectiveness of the proposed approach, the solutions in the present work agree well with the existing results when the non-associated flow rule is reduced to the associated flow rule and the non-linear failure criterion is degenerated to the linear failure criterion. Compared with dilatancy of materials, the non-linear failure criterion exerts greater impact on the stability of shallow tunnels. The safety factor of shallow tunnels decreases and the failure surface expands outward when the dilatancy coefficient decreases. While the increase of nonlinear coefficient, the pore water pressure coefficient, the surface load and the buried depth results in the small safety factor. Therefore, the dilatancy as well as non-linear failure criterion should be taken into account in the design of shallow tunnel supporting structure. The supporting structure must be reinforced promptly to prevent potential mud from gushing or collapse accident in the areas with abundant pore water, large surface load or buried depth.     

西门子S7-400的热连轧层流冷却自动控制系统

为了热轧带钢顺利卷取并保持良好卷形,同时保证带钢成品性能指标,必须使带钢卷取温度控制在合理的范围,现代热连轧生产线基本上都采用层流冷却技术来进行卷取温度控制.针对莱钢1 500 mm热连轧生产线,设计了一套具有国内领先技术水平的层流冷却系统.详细阐述了自动控制系统的配置、系统功能、控制模型和控制策略.系统在现场得到成功应用,结果表明,该系统结构合理、功能完善、性能稳定可靠、控制精度高.     

MODIS-TVDI指数监测新疆干旱动态

针对近年频发的干旱情况不能准确及时监测评估的问题,该文以新疆为研究区域,基于温度植被干旱指数方法,利用2007年到2012年3月~8月MODIS合成产品数据获取归一化植被指数和陆地地表温度,构建LST-NDVI特征空间,得到全区的温度植被干旱指数和旱情等级空间分布图,分析了新疆干旱变化趋势,验证了温度植被干旱指数和降水因子的关系。结果表明:2007年~2012年新疆的干旱面积逐年趋于平稳,空间上表现为南疆旱情高于北疆,春季旱情高于夏季,降水量是影响温度植被干旱指数的重要因子。该研究为政府部门对新疆旱情严重地区治理提供了有效数据保证。     

以气孔导度为显参的遥感—光合水分胁迫作物产量模型研究

本文给出利用遥感信息和作物生理参数研究遥感－光合水分胁迫作物产量模型的概念，建立以作物气孔导度显参的遥感－光合水分胁迫作物产量模型；对模型的参数给出求解公式，最后进行华北平原典型区的遥感－光合水分胁迫作物产量模型的作物产量填图，并于已有模型的应用结果比较，发现本文发展的模型有可比的精度。     

景观信息流及GIS对脆弱生态异质性制图的分析

分析了依信息学确立的景观信息流在景观异质性制图的意义，及景观信息流的测度、特征和遥感与ＧＩＳ对其获取的方法，探讨了景观信息流转换的表达方式。其次，把景观信息流反映在地学异质信息中，着重分析脆弱生态景观地学的异质性特征、响应以及利用ＧＩＳ建立脆弱生态景观异质性制图的方法，对科尔沁沙地东南部的景观异质性特征作了分析。