基于Argo数据的吕宋海峡东部海域的会聚区特征分析

利用2010-2013年的Argo浮标观测资料,对吕宋海峡东部海域(19°~23°N,123~127°E)的会聚区特征进行综合分析。研究结果如下:(1)吕宋海峡东部海域4个季节表面的声速从大至小依次为夏季、秋季、春季和冬季,夏季最大为1 543.5m/s,冬季最小为1 533.4m/s;混合层深度从大到小依次为冬季、秋季、春季和夏季;(2)采用WOA13气候态数据对声速剖面进行深海延拓,获得全海深的声速剖面,分析4个季节的声道特征。声道轴深度和声速较为稳定,声道轴深度在1 000~1 040m之间,声道轴处的声速为1 482m/s,4个季节的平均声道厚度都超过4 500m,利于会聚区形成;(3)研究区较易发生会聚现象,发生会聚现象概率高于50%的占70.6%;会聚现象的发生概率季节变化明显,春季、冬季极易发生声场的会聚现象,夏季最小;(4)运用RAMGeo声场模型对研究区4个季节的声传播损失进行仿真,分析会聚区的季节变化特征。当声源深度100m,接收深度10m时,第一会聚区,离声源的距离在61~64km左右,夏季离声源最近,春、冬季较远;会聚区宽度上,夏季最宽为10km,春季最窄为4.6km;会聚区增益分布特点与会聚区宽度刚好相反,春季最大为14.6dB,夏季最小为8.5dB。     

中国历史探空资料部分等压面位势高度订正

对中国高空探测历史资料进行静力学检查发现,1963年前900,800,80 hPa和60 hPa位势高度记录错误率异常偏高,20世纪70年代中期个别站250 hPa和70 hPa位势高度记录错误率也异常偏高。通过对中国高空观测规范历史沿革的分析和资料验证,指出受当时计算条件所限,这些等压面上的位势高度是在其他规定等压面的位势高度查表计算完成后,利用时间高度曲线通过人工插值估算获得,主观因素影响较大,易产生较大误差,因而错误率异常偏高。该文提出依据静力学原理重新计算这些等压面位势高度记录的订正方案,并进行效果检验。结果表明:该方案能够比较精确地还原台站观测时对位势高度的正确计算,错误资料订正后,相关高度静力学余差序列趋向均一,订正方案合理、有效。     

Head-on collision of ion-acoustic solitary waves in magnetized plasmas with nonextensive electrons and positrons

This article presents the first study of the head-on collision of two ion-acoustic solitary waves (IASWs) in magnetized plasmas with nonextensive electrons and positrons using the extended Poincaré-Lighthill-Kuo (PLK) method. The effects of the ion gyro-frequency to ion plasma frequency ratio, the positron to ion number density ratio, the electrons temperature to positrons temperature ratio, and the nonextensive parameter q on the phase shifts are investigated. It is shown that these factors significantly modify the phase shifts.     

Relations between stellar mass and electron temperature-based metallicity for star-forming galaxies in a wide mass range

We select 947 star-forming galaxies from SDSS-DR7 with [O III]λ4363emission lines detected at a signal-to-noise ratio larger than 5σ. Their electron temperatures and direct oxygen abundances are then determined. We compare the results from different methods. t2, the electron temperature in the low ionization region, estimated from t3, that in the high ionization region, is compared using three analysis relations between t2- t3. These show obvious differences, which result in some different ionic oxygen abundances. The results of t3, t2, O++/H+and O+/H+derived by using methods from IRAF and literature are also compared. The ionic abundances O++/H+are higher than O+/H+for most cases. The different oxygen abundances derived from Teand the strong-line ratios show a clear discrepancy, which is more obvious following increasing stellar mass and strong-line ratio R23. The sample of galaxies from SDSS with detected [O III]λ4363 have lower metallicites and higher star formation rates, so they may not be typical representatives of the whole population of galaxies. Adopting data objects from Andrews Martini, Liang et al. and Lee et al. data, we derive new relations of stellar mass and metallicity for star-forming galaxies in a much wider stellar mass range: from 106 M to 1011 M.     

城市地下空间三维地质模型可视化技术研究

目前,城市地下空间信息化发展面临着海量数据组织、管理和可视化显示等亟需解决的关键问题。本文顺应国家新型智慧城市建设趋势,提出并实现了城市地下空间三维地质模型可视化技术,构建地质三维模型分级数据,按照不规则四叉树结构形成LOD数据;基于构建的三维空间网格码规范编码,运用降维、非布尔运算的方法,实现最大精度化的地下空间模型数据无限逼近的融合;并采用多渲染引擎的混合渲染架构,支持DirectX、WebGL（OpenGL ES）、OSG（OpenGL）和游戏引擎（Unreal Engine）等多引擎渲染,实现TB级地下时空数据的真实感可视化与高效调度,为城市地下空间开发利用提供数据支持和辅助决策分析支撑。     

Crustal structure and variation along the southern part of the Kyushu-Palau Ridge

As an interoceanic arc, the Kyushu-Palau Ridge（KPR） is an exceptional place to study the subduction process and related magmatism through its interior velocity structure. However, the crustal structure and its nature of the KPR,especially the southern part with limited seismic data, are still in mystery. In order to unveil the crustal structure of the southern part of the KPR, this study uses deep reflection/refraction seismic data recorded by 24 ocean bottom seismometers to reconstruct a detail...     

A Hybrid Logistic Regression: Gene Expression Programming Model and Its Application to Mineral Prospectivity Mapping

Natural Resources Research - Mineral prospectivity mapping (MPM) is a fundamental task in mineral exploration. The logistic regression (LR) method has been widely used as a data-driven tool for MPM...     

基于深度学习的中国连续空间覆盖PM2.5浓度预报

实现全国连续空间覆盖未来小时尺度的PM_2.5浓度实时、高精度预报是一个难题。本文建立基于深度学习的多层长短期记忆迭代模型和改进的空间反向传播神经网络S-BPNN模型来实现全国小时尺度PM_2.5浓度的空间预报。首先,研究基于空间相关性将全国1286个空气质量监测站点在空间上进行自适应分区,并对各个分区分别构建多层LSTM迭代预报模型实现未来24 h各个监测站点的PM_2.5浓度的实时预报。其次,应用改进的S-BPNN空间化模型实现未来24 h全国连续空间覆盖的PM_2.5浓度精细化制图。然后,利用2016—2019年中国PM_2.5监测站的历史数据进行训练和验证,结果显示预报模型和空间化模型的相关系数R²分别为0.88和0.87,表明模型都能实现较高的精度。最后,基于提出的预报模型和空间化模型,辅助从监测站实时获取的大气污染数据和气象数据,通过搭建的大气污染物浓度预报智能化在线信息原型系统可实时发布预报结果并可进行空间化展示。研究实现了全国连续空间覆盖的PM_2.5浓度高时空精度的实时预测,以支持大气污染联防联控和公众环境空间质量信息服务。     

Deep Drilling Campaign in the Western Qaidam Basin,NE Tibetan Plateau and their Revealed Global Temperature Forcing of Salt Formation in the Late Miocene-Quaternary

正The Qaidam Basin in the NE Tibetan Plateau has contributed the largest amount of potash in China.However,how the potash was formed has long been a subject of debate.Here we carried out a deep drilling     

无人机航测系统在滑坡应急中的应用

2017年2月19日3：45左右,甘肃省永靖县黑方台罗家坡发生滑坡。针对滑坡灾害应急过程中对滑坡滑体厚度和体积精确计算的难题,本文采用无人机航测系统,获取滑坡前后的高精度DEM数据源,并结合现场调查,精确计算出滑坡堆积区厚度的分布情况。研究结果表明,罗家坡2^#滑坡长525m,总面积约5.65×10⁴m²,滑坡体总体积约14.7×10⁴m³,最大滑距为368m,滑坡剪出口位于第四系上更新统冲积粉质黏土顶部,堆积区最大埋深8.35m,位于滑坡滑舌的西南侧。根据DOM影像和现场调查,该滑坡危害对象以农田和水渠为主,无房屋受损和人员伤亡,本文通过引入无人机航测系统为滑坡应急抢险救灾提供了一种新的研究方向。