Dendrochronologie     

Bruno Huber 《International Journal of Earth Sciences》1960,49(1):120-131

Zusammenfassung Die Dendrochronologie arbeitet mit der Jahresschichtung des Holzes. Der Zuwachs gleichzeitig wachsender Hölzer ist ähnlich. Diese Forschungsrichtung braucht viel Material zur Herstellung typischer Mittelkurven. Mit Hilfe der Überbrückungsmethode kommt man örtlich sehr weit zurück. Schwierigkeiten liegen in der gesetzmäßigen Abnahme der Ähnlichkeit von Jahresringkurven mit der Entfernung voneinander. Neben einer absoluten Chronologie sind in Deutschland relative Chronologien aus Jungsteinzeit und Bronzezeit erarbeitet worden. Die Dendrochronologie kann gewisse Aussagen über Klimaschwankungen machen.  相似文献   

Über die Messung von Massensehwächungskoeffizienten bei der Phasenanalyse mit dem Zählrohrgoniometer     

Dr. Bruno Brehler 《Contributions to Mineralogy and Petrology》1957,6(1):52-58

Zusammenfassung Es wird ein Verfahren angegeben, um bei der röntgenographischen Gemischanalyse mit dem Zählrohrgoniometer, dann wenn die Gefahr von Textureffekten nicht besteht, die Intensitäten der Analysenlinien und den Massenschäwachungskoeffizienten in demselben Präparat messen zu können; dazu wird in den Boden des Präparatträgers eine Einkristallplatte eingekittet und die Schwächung gemessen, die ein Reflex der Kristallplatte durch Einbringen der Präparatsubstanz erfährt.  相似文献   

车载激光点云道路边界提取的Snake方法   总被引：2，自引：0，他引：2  

方莉娜  卢丽靖  赵志远  王昀昀  陈崇成 《测绘学报》1957,49(11):1438-1450

针对车载激光点云中道路边界提取困难,自动化程度低的问题,提出一种基于离散点Snake的车载激光点云道路边界提取方法。不同于传统基于图像建立Snake,本文直接基于离散点建立Snake模型。先利用伪轨迹点数据,确定初始轮廓位置,参数化不同类型的道路边界初始轮廓;然后基于离散点构建适合多类型道路边界的Snake模型,定义模型内部、外部和约束能量,通过能量函数最小化推动轮廓曲线移动到显著道路边界特征点处,实现不同道路边界的精细提取。本文试验采用3份不同城市场景的车载激光点云数据验证本文方法的有效性,道路边界提取结果的准确率达到97.62%,召回率达到98.04%,F1-Measure值达到97.83%以上,且提取的道路边界结果与软件交互提取的结果有较好的吻合度。试验结果表明,本文方法能够修正噪声、断裂等数据质量对道路边界提取的影响,能够实现各类复杂城市环境中不同形状道路边界的提取,具有较强的稳健性和适用性。  相似文献   

洱源FD-105K与FD-125测氡仪对比观测分析     

段美芳  李庆  陆丽娜  字承柱  李燕池 《地震地磁观测与研究》2020,41(2):123-129

选取2015—2019年洱源水化站FD-105K与FD-125测氡仪对比观测资料,采用一阶差分、F检验、t检验等方法进行对比分析,结果显示:FD-125测氡仪测值总体偏低,且测量精度较低,数据离散程度较高;2套观测数据变化趋势一致性不理想,相关性较低,未通过F检验和t检验。综合分析认为,FD-125测氡仪暂时不能替代FD-105K测氡仪进行观测,需要增加震例对2套仪器的映震效能进行验证。  相似文献   

Towards urbanisation of the non-hydrostatic numerical weather prediction model Lokalmodell (LM)     

Lina Neunhäuserer  Barbara Fay  Matthias Raschendorfer 《Boundary-Layer Meteorology》2007,124(1):81-97

Numerical weather prediction models are increasingly employed for providing meteorological data for urban air quality applications. Model resolution, physiographic parameters and surface-layer parameterisations need to be adapted to the requirements of the urban boundary layer. The Lokalmodell of the German Weather Service was triple-nested down to a horizontal grid resolution of 1.1 km, urbanised physiographic parameters were implemented, and an additional anthropogenic heat source was introduced. Results of a sensitivity study for a spring dust episode in Helsinki show a clear urbanisation effect of these measures on temperature, humidity and the partitioning of surface fluxes, leading to an increased Bowen ratio and heat storage and an urban heat island effect.  相似文献   

洛阳市暴雨时空分布特征     

Guan Lina  Zhang Lijuan  Ren Jian  Feng Linfan  Liu Jingli 《河南气象》2007,(Z1)

对洛阳市1961-2005年10个站逐日雨量资料统计分析结果表明:洛阳暴雨集中在7-9月,且7-8月单站暴雨较多。有2个暴雨多发区域中心,一个在北部的丘陵区,另一个在南部山区。年区域暴雨出现≥4次时,有准3 a的周期变化规律;≤3次时,有准5 a的周期变化规律。  相似文献   

Correcting superconducting gravity time-series using rainfall modelling at the Vienna and Membach stations and application to Earth tide analysis     

Bruno Meurers  Michel Van Camp  Toon Petermans 《Journal of Geodesy》2007,81(11):703-712

We demonstrate the possibility to improve the signal-to-noise ratio of superconducting gravity time-series by correcting for local hydrological effects. Short-term atmospheric events associated with heavy rain induce step-like gravity signals that deteriorate the frequency spectrum estimates. Based on 4D modeling constrained by high temporal resolution rain gauge data, rainfall admittances for the Vienna and Membach superconducting gravity stations are calculated. This allows routine correction for Newtonian rain water effects, which reduces the standard deviation of residuals after tidal parameter adjustment by 10%. It also improves the correction of steps of instrumental origin when they coincide with step-like water mass signals.  相似文献   

Validation of climate model output using Bayesian statistical methods     

Mark A. Snyder  Bruno Sansó  Lisa C. Sloan 《Climatic change》2007,83(4):457-476

The growing interest in and emphasis on high spatial resolution estimates of future climate has demonstrated the need to apply regional climate models (RCMs) to that problem. As a consequence, the need for validation of these models, an assessment of how well an RCM reproduces a known climate, has also grown. Validation is often performed by comparing RCM output to gridded climate datasets and/or station data. The primary disadvantage of using gridded climate datasets is that the spatial resolution is almost always different and generally coarser than climate model output. We have used a Bayesian statistical model derived from observational data to validate RCM output. We used surface air temperature (SAT) data from 109 observational stations in California, all with records of approximately 50 years in length, and created a statistical model based on this data. The statistical model takes into account the elevation of the station, distance from coastline, and the NOAA climate region in which the station resides. Analysis indicates that the statistical model provides reliable estimates of the mean monthly SAT at any given station. In our method, the uncertainty in the estimates produced by the statistical model are directly determined by obtaining probability density functions for predicted SATs. This statistical model is then used to estimate average SATs corresponding to each of the climate model grid cells. These estimates are compared to the output of the RCM to assess how well the RCM matches the observed climate as defined by the statistical model. Overall, the match between the RCM output and the statistical model is good, with some deficiencies likely due in part to the representation of topography in the RCM.  相似文献   

卫星遥感数字正射影像（RSDOM）局部变形的处理     

穆利娜  李发红 《测绘技术装备》2007,9(1):31-32

在利用卫星遥感数字正射影像(RSDOM)进行数字线划地图(DLG)更新中,多源遥感影像经几何纠正、融合后存在局部变形,严重影响着后序的更新。结合生产实践,本文提出一些解决局部变形的方法。  相似文献   

Solar Coronal Plasma in Doppler Measurements     

Bruno Bertotti  Giacomo Giampieri 《Solar physics》1998,178(1):85-107

Doppler tracking of an interplanetary spacecraft near solar conjunction is strongly affected by the plasma in the solar corona, the main competitive contribution in measurements of the gravitational deflection of light rays. With the simultaneous availability of carriers in X band and K_a band for interplanetary communications, the plasma contribution to the corona can be accurately eliminated and measured. If, as in the Cassini mission, three different observables are available, this can be done in two ways: one deals with the total plasma content in the electric approximation, even in the ionosphere and interplanetary space; another is limited to the corona, but has access to subtler effects, like the magnetic correction to the refractive index. This technique will allow important progress in the radio investigation of the solar corona.  相似文献