基于航测的云底气溶胶活化率与过饱和度估算

2016年11月13日在北京地区上空存在持续稳定的层状云天气背景下,利用飞机开展气溶胶粒径谱、化学组成、云滴谱等参量的垂直观测,研究该个例云底气溶胶的活化能力。结果表明：探测期间北京地区为轻度污染天气,地面气溶胶浓度(0.11~3 μm)达到4600 cm-3。云层高度为800~1200 m,云底气溶胶数浓度相对于近地面大幅度降低,有效粒径显著增大(0.3~0.6 μm)。同时,近地面气溶胶中疏水性的一次有机气溶胶贡献显著,而云底气溶胶中一次有机气溶胶的贡献大幅降低,无机组分和二次有机气溶胶的贡献明显增大,造成吸湿性参数κ由0.25(地面)增大至0.32(云底)。云中气溶胶和云滴的谱分布衔接较好,且两者的数浓度之和与云底气溶胶浓度一致,可分别代表未活化和已活化的粒子。基于云底气溶胶粒径谱和吸湿性参数计算得到不同过饱和比下云凝结核的活化率,通过与云中观测结果对比,反推得到云底过饱和度约为0.048%。     

风沙对结构冲击作用的研究进展与展望

沙尘暴本质为风携沙的气固两相流,对建构（筑）物产生的作用力由风荷载和沙粒的冲击荷载组成。遗憾的是,目前的结构抗风设计仅考虑风荷载作用,忽略了沙粒对结构的冲击效应,且因为研究手段有限,目前的研究成果不足以全面地反映风沙对结构物冲击行为的机理。文中将沙粒的冲击行为研究现状分为3部分：冲击前沙粒的运动、冲击时的接触碰撞以及冲击后的冲蚀磨损,以此概述了风沙对结构物冲击行为的研究现状,并总结了目前研究中出现的主要问题,最后提出将数学模型推导、风沙风洞试验、现场实测、数值模拟4个方面系统结合,综合开展风沙流及沙粒对结构的冲击机理及冲击作用研究的展望。     

Q235B结构钢颈缩后的力学行为研究

文中主要依据普通拉伸板材试样的试验结果对Q235B结构钢在单调颈缩后的塑性行为展开研究。为了准确观测Q235B结构钢颈缩后的变形历程,采用DIC光测系统对拉伸试样不同标距范围内的变形展开全过程追踪。此外,为了重现Q235B结构钢颈缩后的力学行为,提出了一种新型力学本构模型,并通过UMAT子程序的形式嵌入到ABAQUS平台。关于力学模型中的材料参数,提出了一种简单的标定流程。最后,采用经过标定的新型力学模型对四组拉伸试样展开有限元分析,数值模拟的拉伸曲线、最大力以及断裂时刻的轴向应变分布与试验结果高度吻合,表明新模型以及相关材料参数的选择与标定是合理且准确的。     

新型闪电电场变化测量仪的研究与初步应用

闪电电场变化测量系统是目前用于闪电物理研究以及闪电定位的重要手段之一, 提高测量系统的探测性能, 对于推动闪电物理以及闪电定位的研究具有重要作用。根据电磁感应原理, 研制出探测带宽为10 Hz~5 MHz的新型闪电电场变化测量仪。并进行了实验, 标定了测量仪输出信号与电场变化信号在频域上的数值关系。利用三套测量仪系统对南京多个强雷暴过程展开同步探测, 利用获取的数据反演了负地闪电场波形。对探测到的58次负地闪波形特征进行统计, 与国内外统计结果进行对比分析, 发现各个地区的负地闪预击穿过程和首次回击电场波形特征存在较大差异。     

GasBench-IRMS在碳酸盐岩δ^13C和δ^18O在线连续分析中的应用

采用GasBench-IRMS气体质谱分析技术，实现了碳酸盐岩中碳氧同位素的在线连续分析。优化了色谱柱温、离子源参数等工作条件，排除了空气中N2O的干扰。结果表明，色谱柱柱温为40℃、65℃时，方法线性范围较宽，结果准确可靠。方法用于碳酸盐岩国家一级标准物质中δ^13C和δ^18O的测定，结果与标准值一致。     

Characteristics of the Variation of Cross Fault Short-Baseline and Short-Range Leveling in Western Yunnan Earthquake Test Site Before Lijiang M_S7.0 Earthquake

Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline and short-range leveling in WYETS before the Lijiang MS7.0 Earthquake occurred in February 1996 only Yongsheng observation station (epicentral distance 82 km) located at Chenghai fault shows great variation about one year before the earthquake. And the nearest observation station, Lijiang (epicentral distance 42 km); presents great coseismic variation, but does not show obvious anomalous variation before the earthquake. There are no significant variations related to the earthquake at the other three observation stations. Two methods are used in analysis of the observed data and some valuable results have been obtained.     

Heterogeneous strain regime in the eastern margin of Tibetan Plateau and its tectonic implications

The eastern margin of Tibetan Plateau is one of the most active zones of tectonic deformation and seismicity in China. To monitor strain buildup and benefit seismic risk assessment, we constructed 14 survey-mode global position system(GPS) stations throughout the northwest of Longmenshan fault. A new GPS field over 1999–2011 is derived from measurements of the newly built and pre-existing stations in this region. Sequentially,two strain rate fields, one preceding and the other following the 2008 MW7.9 Wenchuan earthquake, are obtained using the Gausian weighting approach. Strain field over1999–2007 shows distinct strain partitioning prior to the2008 MW7.9 Wenchuan earthquake, with compression spreading over around Longmenshan area. Strain field derived from the two measurements in 2009 and 2011 shows that the area around Longmenshan continues to be under striking compression, as the pattern preceding the Wenchuan earthquake, implying a causative factor of the sequent of 2013 MW6.7 Lushan earthquake. Our GPSderived dilatation shows that both the Wenchuan and Lushan earthquakes occurred within the domain of pronounced contraction. The GPS velocities demonstrate that the Longriba fault underwent slight motion with the faultnormal and-parallel rates at 1.0 ± 2.5 mm and 0.3 ± 2.2 mm/a; the Longmenshan fault displayed slow activity, with a fault-normal rate at 0.8 ± 2.5 mm/a, and a fault-parallel rate at 1.8 ± 1.7 mm/a. Longriba fault is on a par with Longmenshan fault in strain partitioning to accommodate the southeastward motion of eastern margin of the Tibetan Plateau. Integrated analysis of principal strain tensors, mean principal stress, and fast directions of mantle anisotropy shows that west of Sichuan is characterized as mechanically strong crust-mantle coupling.     

移动Agent 在集群系统中的应用研究

从任务级的角度，在基于主／从模式的集群系统中引入了移动Agent技术，建立了基于移动Agent的并行计算模型。基于该模型，对移动Agent之间的通信接口、容错机制和负载平衡策略等问题进行了研究。     

高精度磁测在山西省繁峙吐楼铁矿区勘探中的应用

该文阐述了高精度磁测工作在山西省繁峙吐楼铁矿区的应用,其高精度磁测目的是查清异常分布,查找隐伏铁矿体,圈定铁矿体分布范围、矿体位置、形态、大小、产状、边界等几何特征及查明矿区地质特征,根据现有探采工程揭露控制,初步估算了铁矿石资源量。