Variations in the provenance of sediment from ice sheets surrounding Baffin Bay during MIS 2 and 3 and export to the Labrador Shelf Sea: site HU2008029‐0008 Davis Strait          下载免费PDF全文

JOHN T. ANDREWS  OLIVIA T. GIBB  ANNE E. JENNINGS  QUENTIN SIMON 《第四纪科学杂志》2014,29(1):3-13

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Feldspar composition as an efficient tool for tephra identification: a case study from Holocene and Lateglacial lacustrine sequences (Jura,France)          下载免费PDF全文

GWÉNOLÉ JOUANNIC  ANNE‐VÉRONIQUE WALTER‐SIMONNET  GILLES BOSSUET  CAROLE BEGEOT  ANNE‐LISE DEVELLE 《第四纪科学杂志》2015,30(6):569-583

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面向粮情检测数据的可视化研究与应用     

胡昊  夏元平  乐颖 《测绘科学》2021,46(11):181-186

现阶段的粮仓检测数据以表格、图片或者文字描述为主,可视化程度较低,缺乏对粮情信息的直观立体表达.为了解决当前存在的数据表达形式单一,直观性不强等问题,将温度传感器检测到的温度数值和激光扫描仪获取的散点空间坐标进行数据处理与分析,利用三维可视化的方法,使用开源的Web端可视化引擎,将检测的粮情数据生成浏览器端的三维模型.通过Web端建立的粮仓三维可视化模型,不仅提高了粮情信息的可视化程度,并且方便仓储管理人员实时监测仓库粮情的动态变化情况.  相似文献   

基于PPK的龙口水位测量及自适应提取方法研究     

张红梅  顾玉亮  乐勤  吴敬文 《武汉大学学报(信息科学版)》2011,(1):44-47

在系统分析龙口水域水文特点的基础上,基于GPS PPK测量技术,设计并研制出了浮球漂流水位连续测量系统。对系统测量数据的处理方法进行了详细研究。将该系统及数据处理算法应用于龙口水域截流区的连续水位测量和提取中,取得了理想的效果。  相似文献   

水电项目对越南硒圣河地区社会经济发展及环境保护的影响     

乐庭青  武四兰 《资源与生态学报(英文版)》2011,(4):375-379

硒圣河是湄公河的主要分支之一,其集水区地形条件和水资源量均对水电开发十分有利。此外,无论从物种多样性还是生物量来看,硒圣河水生生物资源非常丰富。鱼类是当地人们的重要食物来源,粗略估计鱼类物种数量可能在200-300种之间,目前具有详细记录的鱼类大约为120种。截至目前,从越南境内硒圣河上游至越-柬边界总共开发了6个水电项目,兴建了一座4A级硒圣调蓄水库。流经柬埔寨的硒圣河部分,依据发展规划将兴建3座水电站,即硒圣5号电站（硒圣1号电站以下）、硒圣3号电站、硒圣2号电站。硒圣河水电项目对区域（越南和柬埔寨）社会经济的影响体现在：为地处偏远和困难的集水区创造了新的能源资源,改善了交通系统和农村地区的生活条件。与此同时,这些水电项目也对该区域自然环境产生了重大影响。例如,改变了下游流动机理变化,导致下游河道淤积,对沿河生态系统也产生了一定影响。  相似文献   

A Statistical Analysis of X1- and X2- or Higher-Class Flares during Solar Cycles 21∼23     

YANG Xing-xing  LE Gui-ming  ZHANG Cheng-yi  YIN Zhi-qiang  ZHAO Wei 《Chinese Astronomy and Astrophysics》2014

The X1- and X2- or higher class ?ares in solar cycles 21, 22, and 23 from 1986 to 2008 have been analyzed statistically in this paper. It is found in the statistical study that the number of the X1-class ?ares accounted for 52.71% of total X- and higher class ?ares, while, the number of the X2- and higher class ?ares accounted for 47.29% of total X- and higher class ?ares. No matter whether the X1- and X2- or higher class ?ares, most of them occured in the descending phases of the solar cycles. Moreover, the weaker the intensity of the solar cycle, the higher the ratio of the ?ares occurred in the descending phase of the solar cycle, and the stronger the intensity of solar ?ares, the higher the ratio of the ?ares occurred in the descending phases of the solar cycles. In addition, the phase difference between the peak of the smoothed monthly mean number of sunspots and that of the X-class ?ares has been calculated, which shows that the smoothed monthly mean number of the X1-class ?ares had a very noticeable time advance of 1 month with respect to that of sunspots in the cycles 21 and 22, but there was a time lag of 13 months in the cycle 23, while, for the X2- and higher class ?ares, there was a time lag of 9 months in the cycle 21, but a one-month time advance existed in the cycle 22, and again a time lag of 32 months appeared in the cycle 23.  相似文献   

The China Clipper — fast advective transport of radon-rich air from the Asian boundary layer to the upper troposphere near California     

MARK A. KRITZ  JEAN-CLAUDE LE ROULLEY  EDWIN F. DANIELSEN 《Tellus. Series B, Chemical and physical meteorology》1990,42(1):46-61

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Numerical studies of the surface-wave effects on the upper turbulent layer in the ocean     

LE NGOC LY 《地球，A辑:动力气象学与海洋学》1990,42(5):557-567

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Reconstructing P–T paths during continental collision using multi-stage garnet (Gran Paradiso nappe, Western Alps)     

B. LE BAYON  P. PITRA  M. BALLEVRE  M. BOHN 《Journal of Metamorphic Geology》2006,24(6):477-496

Garnet–chloritoid-bearing micaschists from the Gran Paradiso massif (Western Alps) contain evidence of a polymetamorphic evolution. Detailed textural observations reveal that two stages of garnet growth are present in the micaschists, interpreted as: (i) relics of an early metamorphism of pre-Alpine age and (ii) newly grown Alpine garnet, respectively. Both generations of garnet preserve growth zoning. From thermocalc -based numerical modelling of mineral assemblages in pressure–temperature ( P – T ) pseudosections, we infer that garnet 1 grew at increasing temperature and slightly increasing pressure, whereas garnet 2 grew at decreasing pressure and slightly increasing temperature. Estimated P – T conditions are ∼620 °C, 6 kbar for the peak of the pre-Alpine event, and of 490 °C, 18–20 kbar for the pressure peak of the Alpine event. Modelling of the modal proportion and chemical composition of garnet (i) shows that the subsequent decompression (to 14–15 kbar at 550 °C) must have been accompanied by moderate heating and (ii) does not support a stage of final temperature increase following decompressional cooling. This argues against a late thermal pulse associated with mantle delamination. Preservation of growth zoning in both generations of garnet and the limited amount of diffusive re-equilibration at the boundary between the two garnets suggests that the rocks were subjected to fast burial and exhumation rates, consistent with data obtained from other internal Alpine units.  相似文献   

Spatial and temporal variability of land CO₂ fluxes estimated with remote sensing and analysis data over western Eurasia     

SÉBASTIEN LAFONT  LAURENT KERGOAT  GÉRARD DEDIEU  ANNE CHEVILLARD  UTE KARSTENS  OLAF KOLLE 《Tellus. Series B, Chemical and physical meteorology》2002,54(5):820-833

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