电阻率成像及浅层地震勘探在控盆构造探测中的应用——以万全断裂为例

万全断裂是洋河盆地北缘断裂带组成断裂之一,控制沿线构造活动及地貌发育。断裂走向NE,倾向SE,在沟口处隐伏于第四纪覆盖层,采用电阻率成像和浅层地震联合勘探方法,获得该断裂隐伏段落综合物探异常,结合地质地貌调查,判定隐伏段落展布的具体位置、产状、活动特征及地下结构特征等。研究结果表明,万全断裂隐伏段落走向NE,倾向SE,倾角约75°,上断点埋深约20 m,20—240 m深度可见断裂破碎带（宽约10—20 m）物探异常特征及断裂两侧地层结构差异。该联合探测模式可有效探测复杂地质构造条件下的隐伏活动断裂,具有较强实用性,值得推广。     

Three-dimensional analysis of ozone and PM<Subscript>2.5</Subscript> distributions obtained by observations of tethered balloon and unmanned aerial vehicle in Shanghai,China

A lightweight unmanned aerial vehicle (UAV) and a tethered balloon platform were jointly used to investigate three-dimensional distributions of ozone and PM_2.5 concentrations within the lower troposphere (1000 m) at a localized coastal area in Shanghai, China. Eight tethered balloon soundings and three UAV flights were conducted on May 25, 2016. Generalized additive models (GAMs) were used to quantitatively describe the relationships between air pollutants and other obtained parameters. Field observations showed that large variations were captured both in the vertical and horizontal distributions of ozone and PM_2.5 concentrations. Significant stratified layers of ozone and PM_2.5 concentrations as well as wind directions were observed throughout the day. Estimated bulk Richardson numbers indicate that the vertical mixing of air masses within the lower troposphere were heavily suppressed throughout the day, leading to much higher concentrations of ozone and PM_2.5 in the planetary boundary layer (PBL). The NO and NO₂ concentrations in the experimental field were much lower than that in the urban area of Shanghai and demonstrated totally different vertical distribution patterns from that of ozone and PM_2.5. This indicates that aged air masses of different sources were transported to the experimental field at different heights. Results derived from the GAMs showed that the aggregate impact of the selected variables for the vertical variations can explain 94.3% of the variance in ozone and 94.5% in PM_2.5. Air temperature, relative humidity and atmospheric pressure had the strongest effects on the variations of ozone and PM_2.5. As for the horizontal variations, the GAMs can explain 56.3% of the variance in ozone and 57.6% in PM_2.5. The strongest effect on ozone was related to air temperature, while PM_2.5 was related to relative humidity. The output of GAMs also implied that fine aerosol particles were in the stage of growth in the experimental field, which is different from ozone (aged air parcels of ozone). Geographical parameters influenced the horizontal variations of ozone and PM_2.5 concentrations by changing underlying surface types. The differences of thermodynamic properties between land and sea resulted in quick changes of PBL height, air temperature and dew point over the coastal area, which was linked to the extent of vertical mixing at different locations. The results of GAMs can be used to analyze the sources and formation mechanisms of ozone and PM_2.5 pollutions at a localized area.     

Conductivity model for pyrite-bearing laminated and dispersed shaly sands based on a differential equation and the generalized Archie equation

The conductance of pyrite-bearing laminated and dispersed shaly sands is not well understood and resistivity models for pyrite-bearing shaly sands are nonexistent. Thus, we first synthesize clean pyrite-matrix samples, and quartz-matrix samples with variable laminated shale, dispersed shale, and pyrite content and then perform petrophysics experiments to assess the effect of pyrite content on the conductivity of pyrite-bearing shaly sands. Second, based on the differences in conductivity and conduction pathways and geometries because of the variable composition of the pyrite-bearing laminated and dispersed shaly sands, we divide the shaly sands into their components, i.e., laminated shale, quartz grains, pyrite grains, hydrocarbon, dispersed shale, microscopic capillary water, and mobile water. A generalized resistivity model is proposed to describe the conductivity of pyrite-bearing laminated and dispersed shaly sands, based on the combined conductivity differential equation and generalized Archie equation. In the generalized resistivity model, the conductivity differential equation is used to describe the conductivity of dispersed inclusions in a host, whereas the generalized Archie equation is used to describe the conductivity of two conducting phases. Moreover, parallel conductance theory is used to describe the conductivity of dispersed shaly sands and laminated shale. Theoretical analysis suggests that the proposed model satisfies the physical constraints and the model and experimental results agree. The resistivity and resistivity index of shaly sands decrease with increasing conductivity and pyrite. Finally, the accuracy of the resistivity model is assessed based on experimental data from 46 synthetic core samples with different oil saturation. The model can describe the conductivity of clean pyrite-matrix samples, and quartz-matrix samples with different volumes of laminated shale, dispersed shale, and pyrite. An accurate saturation model of pyrite-bearing laminated and dispersed shaly sands is thus obtained and the log data interpretation in complex shaly sands can improve with the proposed model.     

Source-independent wave-equation based microseismic source location using traveltime inversion

A new source location method using wave-equation based traveltime inversion is proposed to locate microseismic events accurately. With a sourceindependent strategy, microseismic events can be located independently regardless of the accuracy of the source signature and the origin time. The traveltime-residuals-based misfit function has robust performance when the velocity model is inaccurate. The new Fréchet derivatives of the misfit function with respect to source location are derived directly based on the acoustic wave equation, accounting for the influence of geometrical perturbation and spatial velocity variation. Unlike the mostly used traveltime inversion methods, no traveltime picking or ray tracing is needed.Additionally, the improved scattering-integral method is applied to reduce the computational cost. Numerical tests show the validity of the proposed method.     

内蒙古半干旱区沙尘天气特征及其与地表特征的关系

利用2002-2010年朱日和气象站观测资料,结合同期归一化植被指数(NDVI),叶面积指数(LAI),植被净初级生产力(NPP)资料,分析了内蒙古半干旱区朱日和地区2002-2010年的沙尘天气特征。结果表明：朱日和地区临界起沙风速为9.4 m·s-1,2002-2010年沙尘天气频率和大于临界起沙风速频率呈波动变化,沙尘天气频率和大于临界起沙风速频率有很好相关性,超过18 m·s-1的强风极易导致沙尘天气的发生;定义标准化的沙尘天气频率（NfDO）为沙尘天气频率与大于临界起沙风速频率之比,当夏季降水量大于100 mm,夏季最大NDVI、最大LAI和最大NPP分别大于0.24、0.3 g·m-2·d-1和0.6 g·m-2·d-1（以碳计算）时,次年春季NfDO较低,沙尘天气不易发生;反之沙尘天气较易发生。对沙尘天气发生机制的分析发现,夏季有效的降水促进了植物生长,夏季降水量、最大NDVI、最大LAI和最大NPP增大,来年春天土壤不容易侵蚀,沙尘天气不易发生。     

云贵川地区ZTD垂直剖面格网模型

利用ERA5大气再分析资料研究ZTD高程尺度因子的精细时间变化特征,构建顾及高程尺度因子精细时间变化的云贵川地区ZTD垂直剖面格网模型(YZTD-H模型)。以云贵川地区探空站分层ZTD数据作为参考值,检验YZTD-H模型的精度,并将其与GPT2w模型和GPT3模型进行比较。结果表明,顾及精细时间变化和垂直剖面变化的YZTD-H模型在时间维度和垂直剖面维度上均表现出较好的稳定性。     

风云三号C星SEM高能粒子数据检验及应用

风云三号C星(FY-3C卫星)空间环境监测器(SEM)可监测轨道高度上的高能带电粒子(质子、电子和重离子)辐射环境及其引起的辐射剂量和表面充电等空间天气效应,是空间天气监测预警业务不可或缺的自主数据源之一。为验证FY-3C卫星高能粒子探测数据的有效性,需开展数据的定量检验工作。本文采用与同类卫星同类数据进行交叉比对的方式来进行检验。首先,根据一定的假设条件,对比对数据进行归一化处理,尽量消除不同卫星间观测时间、空间(星下点经、纬度和高度)、方向和能量范围等差异对高能粒子分布的影响,然后进行比对,最后计算比对数据间的相关系数、斜率和标准偏差等统计参数,并据此评价比对数据的一致性。通过空间天气平静期高能质子和高能电子与NOAA-18和FY-3B卫星数据的交叉比对可以看出,FY-3C卫星高能粒子数据与比对卫星数据具有较好的一致性。由于工作原理和技术指标相同,FY-3C与FY-3B卫星高能粒子数据的一致性更好,也证明了载荷技术状态的稳定性。通过对太阳质子事件和高能电子暴的观测实例证明,FY-3C卫星高能粒子数据能够准确地反映空间天气扰动事件的特征和强度。以上结果表明,FY-3C卫星高能粒子数据可信度较高,能够用于空间天气监测、预警以及研究工作。     

川北硅质岩型铼多金属矿铼的赋存状态

川北硅质岩型铼多金属矿是国内首次发现的铼矿床新类型,矿石中具有Re、Se、V、Mo等多种有价元素富集,综合利用价值较好.本次通过X射线荧光光谱分析(XRF)、X射线衍射(XRD)、能谱分析(EDS)、电子探针(EPMA)、扫描电子显微镜(SEM)等多种手段开展矿石工艺矿物学及铼的赋存状态研究.结果 表明,矿石中主要矿物包括石英、伊利石、黄铁矿等,并含有大量碳质,Re、Se富集与S紧密相关,V富集与Si、A1紧密相关.黄铁矿电子探针分析结果显示,测点含硒平均值0.021％、铼含量平均值为0.024％,表明铼、硒主要以类质同象形态赋存于黄铁矿中.钒主要赋存于含钒伊利石等黏土矿物中.     

精密三角高程跨河水准测量的改进方法

分析现行规范中一、二等三角高程跨河水准测量方法存在的问题,提出改进方法并进行技术设计。通过在某桥梁工程中进行二等跨河水准测量的实例验证和分析,测回观测成果的合格率高达94.4%,环闭合差小于规定限差一半的测回数超过总测回数的80%,三角高程法与GPS法形成的跨河水准环的闭合差为4.72 mm,小于规定限差。试验表明:改进的三角高程跨河方法具有受外界气候条件影响较小、作业效率高、成果精度良好等优势,特别适合于在跨越距离较大、场地条件复杂、外界气候影响大、不对称垂直折光影响突出的情形下采用。