稀土掺杂对γ-Al2O3相变及烧结行为的影响

研究了稀土氧化物CeO2、La2O3掺杂对γ-Al2O3烧结行为的影响.结果表明各样品的相变起始温度基本一致,但掺杂样品的相变结束温度和最大相变速率对应温度均较纯样品有所升高(La2O3掺杂样品相变结束温度和最大相变速率对应温度分别升高了48 ℃和27 ℃).同时发现La2O3掺杂样品的最终线收缩率小于CeO2掺杂样品,主要是由于La3+离子半径大于Ce4+,其在晶界处的偏聚浓度高于Ce4+,因此对晶界迁移阻碍作用较大.SEM观察表明,相对于纯样品,掺杂样品颗粒细化,密度降低,这主要归结于掺杂稀土在氧化铝晶界上的偏聚阻碍了烧结过程中的物质迁移.     

齿轮箱通用跑合乎台研制

通过梳理分析本公司各类产品内的齿轮箱跑合要求,研发一种通用性较强的跑合平台,平台含控制器、通用安装支架、通用测试电机、各类电机与齿轮箱驱动轴的安装接口等,满足现有各产品及后续产品的齿轮箱跑合要求,提高生产效率,节约生产成本.     

北京山区沟域经济发展的空间结构

Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the dis-tribution of different mountainous elements in valleys are new subjects for the mountain de-velopment studies, and such studies are meaningful both for researches and practices.Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing'smountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing's mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing's mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing's mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing's mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing's mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing's mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing.     

铁法煤田大兴井田煤层气储气层特征

铁法煤田大兴井田共含煤20层,呈北北东向的条带状分布,煤层比较稳定,煤层气资源丰富。本文通过对煤储层特征即煤层结构和割理密度、割理的组合类型分析,再结合煤层气含量及其控制因素、煤层渗透性和煤储层压力、煤的吸附性综合分析及水文地质条件等资料,选择较为有利的区块,进行小规模的生产试验,为以后的煤层气开发,提供可靠的理论支撑。     

阶跃型滑坡综合变形预测及监测预警方法研究

大型库岸滑坡的长期变形在汛期降雨作用下呈现明显的周期性“阶跃式”陡增特征。针对阶跃型滑坡的变形特征，本文提出了一种多源数据“融合-预测-预警”的三步式滑坡监测预警方法：(1)“融合”,即基于经验模态分解法将多点位移监测数据分别分解为趋势项和周期项，采用加权值法分别融合不同监测点的趋势项和周期项位移得到融合趋势项和融合周期项序列，并将两者叠加得到滑坡体的现状综合变形时间序列；(2)“预测”,即引入“一个预测周期”概念，采用滑动多项式拟合法和随机森林算法分别对融合趋势项和融合周期项进行预测并叠加得到滑坡体的预测综合变形时间序列；(3)“预警”,即基于斜率变点分析方法搜索综合变形曲线的“稳定点”和“跃迁点”,确定稳定变形和加速变形区间的斜率，建立阶跃型滑坡的四级递进式分级预警模型，基于该预警模型对滑坡现状进行预警。以向家坝水库某滑坡体自动化位移监测数据为研究对象，采用本文所提方法对该滑坡进行了综合变形预测和监测预警，结果表明：综合变形时间序列可以整体反映滑坡的变形演化规律，且预测结果可靠，根据分级预警模型判断此滑坡体当前处于稳定变形阶段(Ⅰ级预警)。