为了减轻高钛含量下钢水连铸过程夹杂物产生的不利影响,建立了中间包流场、夹杂物运动及去除模型,考虑了气泡对夹杂物的吸附,重点研究了气幕挡墙及其安装位置对流场和夹杂物的影响.结果表明,小粒径颗粒在钢水带动下跟随性好,且自身浮力小,在无吹气情况下,1～10 μm粒径的夹杂物去除率较低.当吹气流量为5 L/min时,Al2O3和TiN夹杂物的去除率均明显提高,在粒径范围1～10 μm内,Al2O3的去除率为21.7％～34.6％,TiN的去除率为22.7％～33.14％.当气幕挡墙位于湍流抑制器和上挡墙之间时,由于钢液形成的回流速度大,夹杂物和气泡碰撞的概率增加,进而被气泡捕获的概率增加,更有利于夹杂物的去除.本研究为高钛钢连铸过程夹杂物去除提供了理论指导.

In order to improve the central segregation and radial distribution of solutes of the 35CrMnSi alloy constructional steel continuous casting billet with a section diameter of 300 mm, Pulsed Magneto-Osillation（PMO） technology developed by the Center for Advanced Solidification Technology was applied. With the PMO treatment in the secondary cooling zone, the distribution uniformity of C along the radial direction of the billet was improved, the range of C decreased by more than 40%, and the ranges of Cr, Mn, Si in the center of the billet decreased by 18%, 16% and 33%, respectively. The serious segregation phenomena of C, Cr, Mn and Si in the center of the billet were eliminated. The solutes distribution of 35CrMnSi alloy constructional steel billet was improved without changing the original continuous casting process. It provides a new method to improve the central segregation by improving the center quality of ?300 mm round billet.

当前,北京、深圳、武汉等城市纷纷提出多中心的发展思路.作为城市建设的一项重要举措,多中心战略必须符合可持续发展目标,然而多中心结构是否有助于提高能源效率亟待检验.利用2017年我国地级及以上城市数据,分别运用改进的社会网络法和超效率EBM模型测度城市多中心度与城市能源效率,实证检验多中心度对城市能源效率的影响.研究发现:城市多中心度与能源效率之间存在倒"U"形变动特征.然而,仅有约25％的样本城市的多中心度突破了拐点,且这些城市主要为大型城市或受地形约束的山地城市,表明对于大多数中小城市而言,多中心度的提升能够促进城市的能源效率.

在芜湖新兴 φ300 mm圆坯连铸机上引入脉冲磁致振荡技术(Pulsed Magneto-Oscillation,简称PMO)以提高铸坯心部质量,探索了PMO电源参数和连铸机拉速对低碳20钢连铸坯质量的影响.结果表明,采用合适的PMO参数处理可显著降低20钢径向碳分布,碳极差比对比坯平均降低50％,且效果稳定.不采用PMO技术,将连铸机拉速从0.75 m/min提高至0.85 m/min后,对比坯低倍不合格,碳极差达到0.12％.采用PMO技术的铸坯仍保持了较好的心部质量,碳极差降低至0.03％,生产效率提高13.3％.

Adam三维数码摄影测量技术适用于测量、地质编录和变形监测等领域.目前,在中国水利水电行业已被得以较为广泛的接受与应用.介绍该技术的背景原理和应用流程,依托如美水电站工程,阐述该技术在现场数据采集、照片合成与精度控制,以及成果解译与应用等关键环节在陡峻高边坡研究中的应用.研究成果证明,摄影测量技术是一种快速、精确、应用方便的地质素描新方法,在地质工程测绘与地质调查工作中具有广泛的应用前景.

采用颗粒流程序从细观角度对在真三轴条件下含单裂隙砂岩的裂纹扩展贯通模式、破裂机理展开研究,重点讨论了不同中主应力对单裂隙砂岩裂纹扩展和其力学特性的影响.研究结果表明:在真三轴压缩条件下,中主应力有助于增大含裂隙砂岩的强度,但过高的中主应力会加快裂纹的扩展、贯通,从而形成宏观破裂面;当中主应力的作用方向与裂隙走向垂直时,裂隙岩石的破坏模式为垂直于裂隙走向形成宏观剪切破裂面,含裂隙砂岩在真三轴压缩条件下的破坏主要为伴随拉破坏的剪切破坏机制.

A three-dimensional numerical model has been established by based on some northeastern tunnel construction's geological conditions and engineering features and the distribution of rock mass structural planes using self-developed GeoSMA system.Meanwhile,the tunnel stability analysis provides advices for this tunnel design and construction.

With an improved experimental setup for AE(acoustic emission),the AE measurement was carried out for the specimens of anisotropic granite in the deformations/failure process under uniaxial compression.Discusses the initiation of microcracks thus induced and their interaction and propagation during damage/failure.A relative source locating method was introduced into the study on the AE occurrences in anisotropic and heterogeneous rock specimens,which is less dependent on sounding wave velocity.The results showed that the method is available to AE occurrences in complex specimens and engineering rock mass with higher reliability and accuracy than before.And it can offer preliminarily a quantitative analysis of locating the source of rock failure process under the action of external loading,thus benefiting the analyses of other failures of engineering rock mass.