10cm地温数据异常分析及仪器故障排除

地温资料数据量大,其数据异常情况较为隐蔽,利用RTD图形显示分钟资料,可较快发现数据跳变。文章以德庆自动气象站2011-07-31的10cm地温数据异常的分析处理为实例,用排除法找出了仪器故障点,提出了提高地温数据质量的改进措施。     

沟槽形表面织构对摩擦噪声的影响

用电加工方法在制动盘蠕墨铸铁材料表面加工出沟槽形表面织构(沟槽深度为30μm、宽度为150μm、间距为500μm),采用球—平面接触方式,选取直径为10mm的Si3N4球为对磨副,对沟槽形织构表面和光滑表面进行了摩擦噪声对比试验,研究了沟槽形表面织构对界面摩擦振动噪声的影响。试验结果表明(以下结论只针对本试验选定尺寸规格的沟槽形表面织构):法向载荷对织构表面产生摩擦噪声强度的影响较小,而对光滑表面产生摩擦噪声的水平具有重要影响;沟槽形织构表面在低法向载荷下较光滑表面更易产生摩擦噪声,但随着法向载荷从5N增大到10N,光滑表面产生的摩擦噪声强度迅速增大并与织构表面的接近;沟槽形表面织构使摩擦系统更易产生多频率的摩擦振动,较早地产生摩擦噪声且其主频率成分较复杂;沟槽形织构表面比光滑表面具有较高的摩擦因数和耐磨性,沟槽形织构的存在明显地改变了接触界面摩擦磨损行为和摩擦噪声特性,但其对应关系需要进一步深入研究。     

Tool-path generation for sheet metal incremental forming based on STL model with defects

Tool-path generation is a key issue in sheet metal incremental forming process, and existing approaches either are prone to computationally expensive or cannot be applied to stereolithography (STL) model including defects. Thus, a new tool-path generation method is presented by adopting the thought of generating cutter-location (CL) data directly from corresponding cutter-contact (CC) data. By analyzing the interference characteristics between fillet-end tool and model surface and considering tangential case and intersection case comprehensively, a discrete computational model is proposed to calculate single-layer interference-free CL contour, instead of computing a precise CL point by checking potential interferences from candidate facet, vertices, and edges, respectively. So this method is more efficient and easier for program implementation. Additionally, a fast recursive search algorithm is developed to identify and extract flat area features, and an efficient 2D invalid loops removal algorithm based on decomposition thought is presented to obtain valid CC contours and CL contours with a near linear time-complexity. Implementation tests prove that the new method is effective and robust for STL model with defects, and tool-path achieved is highly precise. It is also applicable to various tool shapes and suitable for planning various types of tool-paths to meet different SMIF process requirements.     

加氢裂化装置往复压缩机填料密封故障分析与改造

针对加氢裂化装置C102新型往复压缩机填料密封存在的泄漏问题,对压缩机气缸活塞填料密封结构、密封原理及其密封条件进行研究,在对密封填料函结构和填料受力等讨论的基础上,分析压缩机气缸填料密封失效的主要原因,提出改进填料密封环结构、冷却系统、规范密封环加工工艺程序及优化安装等措施。实践证明,改造后密封效果显著提高,设备使用寿命延长。     

航空发动机叶片锻件模型实例检索策略

根据航空发动机叶片锻件的特点,提出了基于相似理论和层次分析（analytic hierarchyprocess,AHP）法的锻件模型实例检索策略。首先,根据锻件的形状特点提出了定性检索空间和定量检索空间,并根据这两个空间包含的信息提出了检索求解过程;其次,根据相似理论中的相关计算公式和AHP法,提出了检索求解所需的基本公式和权重值计算方法;最后,以某型号航空发动机低压转子二级叶片为例,给出了验证实例。     

Hydrogen production from acid- and ammonia-pretreated biomass

Hydrogen production from biomass has potential environmental and economic advantages; however, the factors that lead to low hydrogen production should be investigated. Acid and base pretreatments were applied to investigate the catalytic effects of alkali and alkaline earth metals (AAEMs) on the biomass (wood pellets) samples and hydrogen production through pyrolysis. The pyrolysis behavior and gas yield were analyzed using a thermogravimetric analyzer and drop tube furnace, respectively. The chemical structure characteristics were analyzed using Brunauer-Emmett-Teller specific surface area analyzer, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Chemically pretreated samples yielded considerably higher hydrogen than the raw sample, as confirmed based on the microstructural properties of the biochar samples. Therefore, the physical changes produced a greater effect than the chemical changes caused by the removal of AAEMs.

     

一种新颖的人脸图像超分辨率技术研究

本文针对基于学习的人脸图像超分辨率技术进行研究,采用多分辨率的幻觉脸算法。针对Baker方法（文献[1]）建立的图像金字塔提取高频细节不够丰富的缺点,采用Kirsch算子提取高频特征。它与Baker的一阶、二阶灰度算子结合,能够提取更多的图像信息,使得匹配更为准确。另外将流形学习中的LLE算法思想引入匹配复原过程中,使复原结果获取更完备的高频信息。实验结果表明,本文预测得到的先验模型更为准确,使得最终复原的人脸图像具有更好的视觉效果。     

车用尿素溶液中油质的分析方法探索与建立

目前,车用尿素溶液常规的分析项目有含量、折光率、缩二脲、醛类、碱度、不溶物等,车用尿素溶液的各分析项目均采用比色法,但是带有油性杂质的车用尿素溶液颜色浑浊,无法采用比色法进行定量分析实验。通过对带油性杂质的车用尿素溶液进行乳化、萃取等手段进行去油后,以达到正常分析的目的,并通过大量探索实验,建立车用尿素溶液中油性杂质的分析方法,填补车用尿素溶液油质分析的空白。     

液膜法在贵金属分离富集中的应用

介绍液膜分离技术用于贵金属富集与分离的应用状况。     

三元催化器在柴油机上的应用研究

机内净化技术是降低柴油机微粒与NOx排放的主要技术措施，但随着排放法规的日益严格，后处理成了一种必要。本文介绍了三元催化器的基本工作原理和特点，并根据发动机台架试验结果分析了三元催化器对内燃机动力性、经济性和排放的影响。