岱海与太湖沉积物焦碳和烟炱最近200年历史对比研究

黑碳是不完全燃烧产生的一种难熔的含碳物质的连续统一体,由焦碳（char）和烟炱（soot）组成。岱海与太湖沉积物焦碳和烟炱浓度对比显示,两个湖泊焦碳浓度和通量变化受局地火事件影响,无明显的规律;  而烟炱具有相似的变化历史,主要反映在1970年代后期急剧升高,与中国工业化历史一致。烟炱粒径细小,具区域传输特点,可以通过沉积物指示大气烟炱。结合当前大气气溶胶烟炱浓度,恢复了岱海与太湖地区最近200年来的大气烟炱浓度。其变化趋势与200年来北半球温度对比显示,大气烟炱中的高浓度对应于高温,低浓度对应低温。这种历史关系进一步证实大气烟炱在全球增温中具有极其重要的作用。     

聊城市地下水开采和补源的研究分析

地下水是聊城市重要的而且是主要的水资源,近年来,地下水的开采和补源引起了人们的广泛关注.本文拟对地下淡水资源的时空分布、运动规律、地下水资源计算和评价及聊城市地下水开发利用问题进行一些探讨,对于引黄(河)灌区合理引用黄河水和开采地下水具有重要的指导作用和应用价值.     

L波段雷达探空高度评估及其质量标识

以美国NCEP FNL分析数据和我国GRAPES_GFS预报数据为背景场,对2016年7月1日-2017年6月30日北京探空站的L波段秒级探空位势高度（探空高度）从观测余差、平均偏差、标准偏差、概率密度分布、峰度系数、偏度系数、相关系数和均方根误差等参数进行误差分析。根据分析结果对探空高度进行质量标识,并根据质量标识的结果再次求解参数,评估质量标识效果。结果表明:探空高度质量较好,无论是基于NCEP FNL还是GRA-PES_GFS,探空高度的误差基本在±5 dagpm以内。探测高层的观测余差平均偏差和标准偏差表明基于GRAPES_GFS的评估优于NCEP FNL的评估。单一个例选取的可疑点和错误点阈值具有误差特征、自适应的特点。     

基于无人机倾斜摄影的数字露头实景三维模型构建

地质露头在地质研究中具有极其重要的地位。传统地质露头野外数据采集多以相机拍照、人工测量为主,存在诸多局限性。基于无人机的倾斜摄影技术及其配套的快速三维建模技术是近年发展起来的高新技术。本文将无人机倾斜摄影技术引入地质露头数据采集中,研究了基于无人机倾斜摄影的数字露头实景三维模型构建方法并详细论述了工作流程。文章以鄂尔多斯盆地大石头井沟剖面和二道沟剖面为例进行了案例分析。研究表明：基于构建的数字露头实景三维模型可进行剖面量测、岩层岩性分析、岩层走向分析、岩层叠覆情况分析等多种地质分析。相较于传统地质露头数据采集方式,该方法具有真实全面、高效易用的特点。     

Variable temperature and moisture conditions in Yungang Grottoes,China, and their impacts on ancient sculptures

Deterioration of grottoes induced by the negative impacts of the variable temperature and moisture conditions has been an important issue in the conservation of heritage sites in China. In this case study, the spatial distributions and varying patterns of moisture and temperature in the caves of Yungang Grottoes, China, were investigated. The relative air humidity was approximately 100 % in the deep zone of the unsaturated surrounding rocks of the grottoes where the temperature remained almost steady at around 9.4 °C. However, the indoor air temperature, relative humidity, and rock surface temperature in the caves varied significantly because of the active exchange of the air with the outside atmosphere. The condensation water appeared on cave walls in the summer when the dew point in the air was higher than the rock surface temperature. Preliminary assessments with a special collection device indicated that the thickness of the transient condensation water could reach 0.03–0.10 mm on the back wall of a cave. The occurrence of this condensation water is expected to worsen salt deterioration of the sculptures in the grottoes. As revealed by long-term observations, a wooden building in front of a cave can weaken the indoor air temperature fluctuation and reduce the condensation water, and consequently, prevent the negative effects of the microclimate for the sculptures.     

非均质条件下珠江口潮汐湿地地下水流动特征

开展非均质条件下潮汐湿地中地下水流动特征研究,成为深入揭示潮汐湿地水循环及物质循环过程的重要前提。以广州南沙区的河畔潮汐湿地为对象,基于放射性氡同位素示踪技术考察含水层非均质情况下地下水的流动特征。结果表明：1）研究区介质干容重、介质孔隙度和介质氡释放（E_{rn}）呈现空间异质性,介质氡释放是导致介质氡平衡能力（[R_n{]}_{gw}）呈现显著空间异质性（2 210.15~7 700.33 Bq/m³）的主要因素。2）非均质条件下地下水流动呈现显著的分区特征,根据氡的比活度可以划分为快速流动区和滞留区。其中,快速流动区地下水氡比活度较小,观测期内平均值为1 522.39 Bq/m³,地下水呈现由陆向海近似“U”型的流动模式。滞留区地下水氡比活度显著增大,观测期内平均值为3 858.40 Bq/m³,地下水受潮汐作用而滞留更久。滞留区地下水流动状态受潮高差影响,潮高差越大,潮汐对湿地地下水的整体驱动力越大,滞留区地下水渗出相对容易,反之滞留区地下水渗出较难。由此可见,潮汐湿地含水层介质的空间异质性是影响地下水流动特征的关键因素。     

武汉市军运会期间空气质量特征及气象条件分析

利用2019年10月1—30日湖北省及邻近地区的空气质量、气象要素监测数据和再分析资料,分析了第七届世界军人运动会(以下简称军运会)期间和前后时段空气质量变化特征及气象条件的影响.军运会管控期Ⅱ(17—28日)与过去五年(2014—2018年)同期相比颗粒物浓度下降最明显,与长沙等其他城市相比也是最低,相近时间段或相似...     

Source and yearly distribution of PAHs in the snow from the Hailuogou glacier of Mountain Gongga,China

Snow samples were collected over a 3-year period from 2012 to 2014 at the Hailuogou glacier of Mountain Gongga (Mt. Gongga) and analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) using Gas Chromatography–Mass Spectrometry (GC–MS). The results show that total average levels of the 16 PAHs ranged from 452 to 290 ng·L^?1 with a possible declining trend from 2012 to 2014. Distances between the sampling sites and the emission sources were estimated at typically less than 500 km. The results suggest that the major source of PAHs was from coal combustion, while contributions from automobile exhaust played an important role in more recent years. This finding was in agreement with the characteristics of presence of local industry, residence, and recent development of tourism of the surrounding areas.     

Gas Flow Characteristics and Optimization of Gas Drainage Borehole Layout in Protective Coal Seam Mining: A Case Study from the Shaqu Coal Mine,Shanxi Province,China

With increasing demands for coal resources, coal has been gradually mined in deep coal seams. Due to high gas content, pressure and in situ stress, deep coal seams show great risks of coal and gas outburst. Protective coal seam mining, as a safe and effective method for gas control, has been widely used in major coal-producing countries in the world. However, at present, the relevant problems, such as gas seepage characteristics and optimization of gas drainage borehole layout in protective coal seam mining have been rarely studied. Firstly, by combining with formulas for measuring and testing permeability of coal and rock mass in different stress regimes and failure modes in the laboratory, this study investigated stress–seepage coupling laws by using built-in language Fish of numerical simulation software FLAC^3D. In addition, this research analyzed distribution characteristics of permeability in a protected coal seam in the process of protective coal seam mining. Secondly, the protected coal seam was divided into a zone with initial permeability, a zone with decreasing permeability, and permeability increasing zones 1 and 2 according to the changes of permeability. In these zones, permeability rises the most in the permeability increasing zone 2. Moreover, by taking Shaqu Coal Mine, Shanxi Province, China as an example, layout of gas drainage boreholes in the protected coal seam was optimized based on the above permeability-based zoning. Finally, numerical simulation and field application showed that gas drainage volume and concentration rise significantly after optimizing borehole layout. Therefore, when gas is drained through boreholes crossing coal seams during the protective coal seam mining in other coal mines, optimization of borehole layout in Shaqu Coal Mine has certain reference values.

     

西藏降水量、气温变化特征及相关关系

本文利用40a逐日降水与气温资料，分析了西藏地区降水量、气温的年变化和年代际变化特征，讨论了气温与降水量的相关关系。结果表明：近几十年来，西藏年平均气温、降水量有明显上升的趋势；气温是影响西藏地区降水量的重要因子之一。绝大多数月份的月平均降水量与前期气温有很好的相关关系，可作为月平均降水量预报的参考依据。