鲁西地区不同岩性地层热响应试验结果浅析          下载免费PDF全文

史启朋  吴晓华  姜福红  李霖  宋帅良  吴延明  孟甲 《山东国土资源》2018,34(2)

为研究地埋管换热器在不同岩性地层的换热情况,在鲁西黄河冲洪积平原、山前冲洪积平原和低山丘陵区进行了以粉土、粉质粘土、细砂,粘土、粉质粘土、中粗砂,灰岩和花岗岩为研究对象的热响应试验,初步试验结果表明:每延米换热量(W/m)和平均热导率(W/m·k)花岗岩灰岩粉质粘土、中粗砂粉土、粉细砂。在岩溶地下水富水性强,径流速度快的地段灰岩平均热导率花岗岩。此项研究结果可为不同岩性地层浅层地温能开发利用工程地埋管换热器类型的选择,浅层地温能评价和开发利用提供基础数据。  相似文献   

顾及地理语境的旅游轨迹停留点语义标注     

范海林  梁明  李佳  段平  王姗姗  王彤 《测绘通报》2019,(6):66-70

轨迹数据作为典型的时空大数据，具有较高的研究和应用价值。然而现有的轨迹数据挖掘主要聚焦于轨迹的空间特征，而较少关注轨迹数据语义的深度分析。本文面向智慧旅游服务的需求，重点探讨了旅游轨迹的轨迹停留点语义的自动标注问题。首先，针对POI短文本的特点，提出了基于《同义词词林》进行短文本语义扩展的方法对POI短文本进行特征扩展；同时，在顾及POI短文本的关键词集中、类别词分散等特征基础上，提出了改进TF-IDF的POI自动分类方法；其次，在POI分类的基础上，采用Native Bayes方法对轨迹停留点进行语义标注。结果表明，基于改进TF-IDF方法的POI自动分类可以达到约83%的精度，能够较好地实现POI的分类；而在POI自动分类基础上，基于Native Bayes的轨迹语义标注可以达到74%的精度，较好地实现了旅游轨迹停留点自动语义标注的目标。  相似文献   

An approach for establishing correspondence between OpenStreetMap and reference datasets for land use and land cover mapping     

Qi Zhou  Xuecan Jia  Hao Lin 《Transactions in GIS》2019,23(6):1420-1443

OpenStreetMap (OSM) provides free source data for land use and land cover (LULC) mapping of many regions globally. Earlier work has used just manual and subjective approaches to establish correspondence between paired OSM and reference datasets, an essential step for LULC mapping. This study proposes an approach to establish correspondence via three steps: (1) convert line feature(s) into polygon feature(s); (2) merge multiple polygon feature(s) into a single layer; and (3) establish correspondence and reclassify OSM and/or reference datasets. Study areas in Sheffield, London, Rome, and Paris were used for testing, and two measures (overall accuracy, OA and kappa index) were used for evaluation. Experiments were designed to verify this approach, with each pair of OSM and reference datasets initially compared after reclassification. Correspondence from one study area was then applied to another for further validation. Results show that OA was between 70 and 90% and the kappa index varied between 0.6 and 0.8. Evaluation also indicates that the correspondence obtained from one study area is applicable to another, and we illustrate the effectiveness of this approach.  相似文献   

单点系泊潜标系统动力学建模与姿态分析     

齐占峰  秦玉峰  史健  贾立双 《海洋技术学报》2019,38(1)

通过对单点系泊潜标进行动力学分析,利用集中质量法建立系统的动力学模型,编制Matlab仿真程序,通过数值模拟获取不同海流条件下,分析潜标系统的姿态。文中将一个典型潜标系统的浮球、锚链、重力锚等部件,利用集中质量法简化为节点,通过模拟真实环境中的海流流速在垂直方向的分布,设计1～5 m/s的流速剖面分布。将节点的物理参数和海流参数代入仿真程序中,得到各节点的姿态、节点间张力以及重力锚与海底摩擦力等数据。分析仿真结果,海流流速与节点的偏降、节点间的张力以及重力锚与海底的摩擦力成正比,仿真结果与实际情况相符。文中设计的建模方法和仿真程序可以为单点系泊潜标的总体设计、姿态估算、锚系配置提供工程参考。  相似文献   

Physical properties of γ Doradus pulsating stars and their relationship with long-period δ Scuti variables     

Sheng-Bang Qian  Lin-Jia Li  Jia-Jia He  Jia Zhang  Li-Ying Zhu  Zhong-Tao Han 《天文和天体物理学研究(英文版)》2019,(1)

We present LAMOST data on 168 γ Doradus(γ Dor) pulsating stars including stellar atmospheric parameters of 137 variables and spectral types for all of the samples. The distributions of period(P), temperature(T), gravitational acceleration(log(g)) and metallicity [Fe/H] are shown. It is found that most γ Dor variables are main-sequence stars with early F spectral types and temperatures from 6880 K to7280 K. They are slightly more metal poor than the Sun with a metallicity range from-0.4 to 0. On the H-R and log g-T diagrams, both the γ Dor and δ Scuti(δ Sct) stars occupy in the same region and some are beyond the borders predicted by current stellar pulsation theories. It is discovered that the physical properties of γ Dor stars are similar to those of long-period δ Sct(P 0.3 d) stars. The stellar atmospheric parameters are all correlated with the pulsation period for short-period δ Sct variables(P 0.3 d), but there are no such relations for γ Dor or long-period δ Sct stars. These results reveal that γ Dor and long-period δ Sct are the same group of pulsating stars and they are different from short-period δ Sct variables. Meanwhile, 33γ Dor stars are identified as candidates of binary or multiple systems.  相似文献   

基于对象BOW特征的高分辨率遥感影像变化检测方法     

罗星  徐伟铭  王佳 《地球信息科学学报》2018,20(8):1150-1159

针对传统基于像素的变化检测方法的缺点,以及底层特征表现能力不足等问题,提出一种基于对象BOW特征的变化检测方法。首先,将经过预处理操作的两期影像进行波段组合得到组合后影像,再考虑地物光谱特征和几何空间信息对组合后影像进行多尺度分割,获得相对应的对象基元;同时,分别提取两幅影像的底层特征（包括影像各波段的均值和方差以及灰度图像的6种纹理特征）。其次,将对象视作文档,像素的特征向量视作单词,利用BOW模型构建影像对象的中层表达,即对象的BOW特征。最后,通过相似性度量算法比较相应对象的BOW特征,从而识别出影像上的变化区域。本文利用2组WorldView-2影像进行了检验,结果表明本文方法的变化检测结果较为完整,精度优于对比方法。本文方法基本能够满足变化检测的需求,为高分辨率遥感影像上的数据挖掘分析提供了有效的手段。  相似文献   

黄河口埕岛海域粉土波致孔压现场监测     

杜星  孙永福  宋玉鹏  赵晓龙  周其坤 《海洋学报》2019,41(7):116-122

波浪会对海床产生反复的作用力，由此引起的土体颗粒间孔隙水压力变化是造成土体液化的主要原因。使用自行研发的孔压监测设备，对黄河口埕岛海域易液化区海底孔压进行了长时间、高精度的观测，并对孔隙水压力、波高以及潮位间的关系进行分析。监测结果显示，本次监测条件下波浪最大作用深度介于0.5～1.5 m之间，超过该作用深度后孔压无明显变化。土体内部孔隙水压力的变化主要由潮位和波高决定，潮位的作用可使孔压缓慢平滑的变化且对超孔压无影响；波高的作用可使孔压快速、剧烈地振荡并导致超孔压的出现。  相似文献   

Validation of Global Evapotranspiration Product (MOD16) Using Flux Tower Data from Panjin Coastal Wetland,Northeast China     

Jia Du  Kaishan Song 《中国地理科学(英文版)》2018,28(3):420-429

Recent advances in remote sensing technology and methods have resulted in the development of an evapotranspiration(ET) product from the Moderate Resolution Imaging Spectrometer(MOD16). The accuracy of this product however has not been tested for coastal wetland ecosystems. The objective of this study therefore is to validate the MOD16 ET product using data from one eddy covariance flux tower situated in the Panjin coastal wetland ecosystem within the Liaohe River Delta, Northeast China. Cumulative ET data over an eight-day period in 2005 from the flux tower was calculated to coincide with the MOD16 products across the same period. Results showed that data from the flux tower were inconsistent with that gained form the MOD16 ET. In general, results from Panjin showed that there was an underestimation of MOD16 ET in the spring and fall, with Biases of -2.27 and -3.53 mm/8 d, respectively(–40.58% and -49.13% of the observed mean). Results for Bias during the summer had a range of 1.77 mm/8 d(7.82% of the observed mean), indicating an overestimation of MOD16 ET. According to the RMSE, summer(6.14 mm/8 d) achieved the lowest value, indicating low accuracy of the MOD16 ET product. However, RMSE(2.09 mm/8 d) in spring was the same as that in the fall. Relationship between ET and its relevant meteorological parameters were analyzed. Results indicated a very good relationship between surface air temperature and ET. Meanwhile a significant relationship between wind speed and ET also existed. The inconsistent comparison of MOD16 and flux tower-based ET are mainly attributed to the parameterization of the Penman-Monteith model, flux tower measurement errors, and flux tower footprint vs. MODIS pixels.  相似文献   

不同类型卫星影像区域网平差方法   总被引：1，自引：1，他引：0  

周平华  李英成  刘晓龙  钱赛男 《测绘通报》2019,(5):121-124,151

传统卫星影像纠正常针对单景影像，且需要一定数量的外业控制点作为参考，严重制约了正射纠正效率。本文提出了一种卫星影像区域网平差方法，利用影像间的连接点进行RPC模型的前方交会，并用少量控制点进行仿射变换，实现了多轨多景卫星影像的区域网平差。经测试，本文方法可有效减少外业控制点，提高卫星影像正射纠正效率。  相似文献   

Assessment of Cryosat-2 and SARAL/AltiKa altimetry for measuring inland water and coastal sea level variations: A case study on Tibetan Plateau lake and Taiwan Coast     

Huan-Chin Kao  Kuo-Hsin Tseng  C.K. Shum  Tzu-Pang Tseng  Yuan-Yuan Jia 《Marine Geodesy》2019,42(4):327-343

Satellite altimetry has been proven as an effective technology to accurately measure water level, ice elevation, and flat land surface changes since the 1990s. To overcome limitations of pulse-limited altimetry, new altimetric missions such as Cryosat-2 and Satellite with ARgos and AltiKa (SARAL/AltiKa), have been designed to have higher along-track spatial resolution to measure more accurately inland water levels for small water bodies, and coastal sea level changes. In this study, we evaluate the performance of Cryosat-2 low-resolution (LRM) and SARin modes and SARAL/AltiKa Ka-band data on two connected lakes in central Tibetan Plateau, and in the coastal region of Taiwan. Results are compared with in situ tide gauge data in Taiwan and altimetric lake level time series from the CNES Hydroweb database. Our results show that water level change trends observed by Cryosat-2 20-Hz retracked observations, the SARAL/AltiKa 40-Hz Ice-1 retracked data, and the Hydroweb measurements are consistent with the estimated water level trend of ～0.30?m/y, during 2011–2017, and 2013–2015, for the Tibetan Migriggyangzham Co and Dorsoidong Co, respectively. For the coastal region, the performance of SARAL/AltiKa is better than that of Cryosat-2 LRM data in Taiwan. This finding demonstrates the superiority of the Ka-band over Ku-band radar altimetry.  相似文献