井下地脉动测试方法及工程意义

井下地脉动测试是一种新型的原位测试手段,本文简介了这种测试方法的要点,并对测试数据的工程价值与应用方法进行了讨论。     

VOCs走航观测在城市污染源排查中的应用

为推进城市空气质量精细化管理工作的实施,实现VOCs污染源精准排查,2019年3-4月,利用单光子电离飞行时间质谱对青岛市重点区域进行了VOCs走航观测。在排查到的污染源中,工业区的VOCs浓度较生活区整体偏高,且生活区、工业区夜间的VOCs浓度均较白天高。VOCs各类组分中,生活区白天苯系物、卤代烃、烯烃、烷烃的占比均在20%左右,夜间苯系物占比明显升高;工业区苯系物在白天和夜间的占比均最高,其他组分相对较小。浓度较高的前10位VOCs物种中,生活区白天烯烃物种占主导,夜间烷烃物种的比重明显增加;工业区苯系物、烯烃物种在白天和夜间的比重均较大,烷烃物种较小。生活区VOCs的污染源主要为机动车尾气排放和油品挥发,工业区主要为企业排放。烯烃和苯系物臭氧生成贡献较烷烃高,特别是丁烯、戊烯、己烯、甲苯、二甲苯/乙苯、三甲苯贡献显著,建议作为优控物种重点管控。     

The Influence of Synoptic-scale Air Flow and Local Circulation on the Dust Layer Height in the North of the Taklimakan Desert

The present study investigates the influences of synoptic-scale air flows and local wind circulations on the dust layer height (DLH) in the Taklimakan Desert, based on lidar observations performed in the north of the desert in March 2003. The DLH fluctuates approximately every three days between 2500 m (above sea level) and 5000 m, including diurnal variations. Meteorological analyses and numerical simulations show that the three-day fluctuation of DLH corresponds with variations in synoptic-scale air flows over the Taklimakan Desert, and the diurnal variations are linked to downdrafts and updrafts that are formed over the north of the desert as part of local circulations. When strong northerly winds prevail in the upper troposphere and a developed valley wind blows toward the Tienshan Mountains in the lower troposphere, the downdrafts strengthen in the middle troposphere over the north of the desert, lowering the DLH to about 2500 m. In contrast, the DLH rises to about 5000 m when the updrafts develop between strong southerly winds in the upper troposphere and a developed mountain wind blowing from the Tienshan Mountains. Simulations for the local circulation behavior without the presence of the Tienshan Mountains demonstrate that the valley and mountain winds on the southern slope of the Tienshan Mountains control the intensity of the downdrafts and updrafts, thereby influencing the DLH over the north of the Taklimakan Desert.     

长江南通段江面风的观测分析

通过在长江南通段江面、江岸建立风观测站,并在江岸建设80m高的风梯度观测塔,与邻近气象站开展了较长时间的风同步观测,获得了实地观测数据.利用同步风观测数据进行对比分析,揭示出长江南通段江面风的观测事实,并利用风梯度观测资料,分析给出了风随高度的变化规律.在此基础上,结合邻近气象站长年的风观测资料,推算了该处的设计基本风速及其他工程设计风参数.分析表明,该处江面风况明显有别于邻近气象站,风参数计算结果也明显高于风工程理论推算值.     

高邮地磁台加卸载响应比与江苏及邻近地区的地震预测

研究分析了高邮地磁台1980～2001年观测资料的加卸载响应比异常与江苏及邻近地区ML5.0以上地震之间的关系,提出了适用于高邮地磁台的地震分析预报参数,并对其内检预报效能进行了评价。     

汇源大厦托换工程沉降监测分析

汇源大厦托换工程影响巨大，其由立柱拆除引起的沉降监测属高精度要求的大型建筑物变形测量，是托换工程实施的重要保障，结合对托换梁、柱的结构受力分析，分3层布设监测点、依工程进展状况制定合理的观测周期，并采取重点监测与验证相结合的原则，使用精密水准仪配加游标卡尺的特制标卡尺的的特制标尺，多台仪器同时观测等方法，及时反馈了梁柱变形动态，指导拆除及托换进程，保证了工程的顺利进行。     

热带海洋大气环境氯离子浓度立体化观测技术研究

目的 对热带海洋环境氯离子开展立体化观测,掌握热带海洋环境下大气氯离子浓度在空间上的分布规律,为海洋大气环境下装备产品和重大工程服役环境研究提供立体化观测数据支撑。方法 在观测海岸线附近科学选点,采用无人机搭载远程控制大气采样器开展大气氯离子浓度立体化观测,对不同空间高度氯离子浓度分布规律进行分析。结果 成功采集万宁某海岸线附近1 km×300 m×100 m区域1 a以上氯离子浓度数据,通过GIS技术分析并建立了氯离子浓度分布三维场,实现了氯离子浓度可视化,并随离海距离、离地高度剖切显示。结论 海南万宁某区域海岸线附近氯离子浓度在冬季最大,夏季最低,且在一定观测范围内,随观测高度增加而先增大、后降低,随离海距离增大而逐渐降低。     

Remote sensing: Using the spatial domain

Objects in the terrestrial environment interact differentially with electromagnetic radiation according to their essential physical, chemical and biological properties. This differential interaction is manifest as variability in scattered radiation according to wavelength, location, time, geometries of illumination and observation and polarization. If the population of scattered radiation could be measured, then estimation of these essential properties would be straightforward. The only problem would be linking such estimates to environmental variables of interest. This review paper is divided into three parts. Part 1 is an overview of the attempts that have been made to sample the five domains of scattered radiation (spectral, spatial, temporal, geometrical, polarization) and then to use the results of this sampling to estimate environmental variables of interest. Part one highlights three issues: first, that relationships between remotely sensed data and environmental variables of interest are indirect; second, our ability to estimate these environmental variables is dependent upon our ability to capture a sound representation of variability in scattered radiation and third, a considerable portion of the useful information in remotely sensed images resides in the spatial domain (within the relations between the pixels in the image). This final point is developed in Part 2 that explores ways in which the spatial domain is utilized to describe spatial variation in remotely sensed and ground data; to design optimum sampling schemes for image data and ground data and to increase the accuracy with which remotely sensed data can be used to estimate both discontinuous and continuous variables. Part 3 outlines two specific uses of information in the spatial domain; first, to select an optimum spatial resolution and second, to inform an image classification.     

基于飞机观测的北京地区气溶胶特征

运12飞机和空中国王飞机在2007~2018年的飞机观测资料,分析了北京地区大气气溶胶近12a来的时空变化特征.结果表明,气溶胶数浓度随时间变化显示负增长趋势,而与之相反,气溶胶有效直径表现出正增长趋势.气溶胶垂直廓线的季节变化和气候条件以及边界层的季节变化紧密相关.在边界层高度,季节性气候变化和地面污染物排放强度的影响下,不同季节以及地面天气形势下的气溶胶垂直廓线特征差异也十分明显.气溶胶在边界层内混合均匀,但由于夏季边界层高度较冬季更高,气溶胶能够在更高的高度范围内混合均匀,从而降低了夏季近地面的气溶胶数浓度.此外,气溶胶在550nm的入射波长下散射系数的垂直变化与气溶胶数浓度有较好的一致性,其高值多出现在冬季以及污染物浓度较高的天气条件下.     

Long-term winter observation of nitrous acid in the urban area of Beijing

The particulate matter (PM) pollution has been significantly improved by carrying out various valid emission control strategies since 2013 in China. Meanwhile the variation trend of nitrous acid (HONO) is worthy to investigate due to its vital role in the atmospheric oxidation process. In this study, field observation in the winter is conducted to investigate the concentration of HONO in an urban area of Beijing. In the winter of 2019, the mean HONO concentration is 1.38 ppbV during the whole winter. Photo-enhanced NO₂ heterogeneous reactions on the ground and aerosol surfaces were found as the possible daytime sources of HONO. Compared to O₃, photolysis of HONO dominates the primary OH sources during the winter time. To understand the HONO pollution patterns by years variation, multi-year data is summarized and finds that primary pollutants including CO and NO decreased, but secondary pollutants i.e., HONO (mostly generated via secondary process) increased. Our study highlights the requirement to mitigate secondary pollution by control HONO concentration.