对Nakai拟合法的改进及实际应用

本文对Nakai拟合法作了改进并应用于计算井水固体潮和气压系数。利用该方法还可以计算井水位对固体潮和气压响应的滞后时间。以鲁06井为例,用本文的方法计算出其井水位的固体潮和气压系数分别为16.9mm/10~(-3)和5.58mm/hPa,滞后时间分别为18.8和22.4分钟。校正后的中误差由8.5mm下降到6.1mm。     

基于等效源的总强度磁异常非线性处理方法

总强度磁异常（ΔT₁）常规处理方法通常将其近似当作磁异常矢量在地磁正常场方向上的投影（ΔT₂）.然而对于高磁环境如磁铁矿处的磁异常场幅值可达10⁴ nT甚至更大的情况,上述近似假设则不再成立,如采用常规处理方法可能会带来明显的误差.本文针对该问题,提出一种基于等效源的总强度磁异常非线性处理方法;该方法根据总强度磁异常获取流程,直接反演实测地磁场总强度幅值与正常场强度幅值之差来求取等效场源.本文首先通过模型试验,分析ΔT₁与ΔT₂的差异;然后将ΔT₁当作ΔT₂采用常规处理方法以及ΔT₁采用新方法得到的结果作对比分析,结果表明新方法处理结果与理论值的差异为常规方法处理结果的1/5甚至更小,充分说明了新方法的有效性;最后将该方法应用于铁矿实测总强度磁异常处理实例中来转换计算磁异常总模量,其实际应用效果进一步体现了高幅值总强度磁异常数据处理过程中采用新方法的必要性.

     

大跨度桥梁强震动数字监测系统的研制

主跨1 196 m的龙江特大桥是我国第一座位于高烈度地震区的大跨度悬索桥,频繁的地震活动对大桥结构安全构成严重威胁。大桥建设时建立了健康监测系统,其中包含多个结构地震反应观测点,随后布设了场地强震动观测系统,这是对大桥地震响应观测的进一步补充和完善。本文详细介绍场地强震动观测系统的设计方案、系统构成、通信方式等。该系统获取的观测结果,可为龙江大桥在地震作用下结构健康诊断提供依据,为大桥结构地震响应分析提供可靠的地震动输入,有助于了解大桥结构在地震动作用下的反应特征, 提高大跨桥梁的抗震设计水平。     

Understanding the dynamical-microphysical-electrical processes associated with severe thunderstorms over the Beijing metropolitan region

The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.     

Research on Estimating Water Storage of Small Lake Based on Unmanned Aerial Vehicle 3D Model

Water Resources - Lake Water storage can be estimated based on Lake Boundary and lakebed terrain. The boundary of a lake can be extracted from the remote sensing satellite image or the Unmanned...     

Crustal structure using receiver function in the east part of A＇nyemaqen suture belt

Twenty broadband seismographs were deployed along Hongyuan, Sichuan to Wuwei, Gansu. 81 teleseismic events were recorded in one year. We computed receiver functions from teleseismic waveform data and obtained S wave velocity structure beneath each station along the profile by using receiver function inversion method. The results revealed that the crustal structure is very complex and crustal average S wave velocity is to be on the low side. Low velocity structure generally exists in the depth range of 10～40 km in the crust between Aba arc fault and northern edge fault of Qinling earth＇s axis and it is a tectonic feature of complex geological process such as ancient A＇nyemaqen Tethys ocean from closing and side colliding to subducted plate exhumed or thrust rock slice lifted. The Moho is about 50 km depth along the profile and is slightly deeper in the south than in the north.     

地动噪声功率谱及动态范围的一致性分析

在和田地震台阵中心子台安放9台CMG-40T型短周期地震计,采用EDAS-24IP数据采集器进行数据采集。对同一时段观测数据的地动噪声功率谱、动态范围等参数进行测定,并对测定结果进行对比,在使用者的角度分析该类型地震计的一致性。     

Heavy metals in particulate and colloidal matter from atmospheric deposition of urban Guangzhou,South China

Suspended particulate matter (SPM) and colloidal matter (COM) in annual dry and wet deposition samples in urban Guangzhou were for the first time collected, and their trace metals were investigated by using inductively coupled plasma mass spectrometry (ICP-MS). The deposition flux of SPM and of metal elements varied largely among the investigated seasons, and reached the maximum in spring. The correlation analysis indicated that significant correlations existed among some of the metal elements in the deposition samples. The enrichment factors (EF) of metals in COM in the deposition ranging from 79.66 to 130,000 were much higher than those of SPM ranging from 1.65 to 286.48, indicating the important role of COM. The factor analysis showed that emissions from street dust, non-ferrous metal production, and heavy fuel oil were major sources of the trace metals. Positive matrix factorization (PMF) model was used to quantitatively estimate anthropogenic source.     

大型湖库滨岸带蓝藻水华堆积风险评估——以巢湖为例

淡水湖库富营养化与蓝藻水华是全球性的突出水环境问题,尤其是滨岸带严重蓝藻水华堆积甚至造成了水体黑臭、威胁饮用水安全等严重危害,科学评估滨岸带蓝藻水华堆积风险、精准识别蓝藻水华易堆积区域是水环境管理与研究中亟待解决的关键科学问题.本研究以我国长江中下游的大型浅水富营养化湖泊巢湖为研究对象,依托流域水文与湖泊水动力模拟、遥...