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841.
将影像全站扫描仪技术应用于山区进行等高线测图,并以肃北大敖包沟矿区为例,探讨该技术在测图方面所带来的优势,以及能否解决传统测图效率安全精度等问题。利用影像全站扫描仪技术,不仅能够获取现场的影像数据,而且能快速高精度地获取带地理坐标的点云数据。利用点云后处理软件快速生成等高线成图,不仅提高了外业数据采集的精度和效率,而且大大提高了内业成图的效率。  相似文献   
842.
Recent research based primarily on exposure ages of boulders on moraines has suggested that extensive ice masses persisted in fjords and across low ground in north‐west Scotland throughout the Lateglacial Interstade (≈ Greenland Interstade 1, ca. 14.7–12.9 ka), and that glacier ice was much more extensive in this area during the Older Dryas chronozone (ca. 14.0 ka) than during the Younger Dryas Stade (ca. 12.9–11.7 ka). We have recalibrated the same exposure age data using locally derived 10Be production rates. This increases the original mean ages by 6.5–12%, implying moraine deposition between ca. 14.3 and ca. 15.1 ka, and we infer a most probable age of ca. 14.7 ka based on palaeoclimatic considerations. The internal consistency of the ages implies that the dated moraines represent a single readvance of the ice margin (the Wester Ross Readvance). Pollen–stratigraphic evidence from a Lateglacial site at Loch Droma on the present drainage divide demonstrates deglaciation before ca. 14.0 ka, and therefore implies extensive deglaciation of all low ground and fjords in this area during the first half of the interstade (ca. 14.7–14.0 ka). This inference appears consistent with Lateglacial radiocarbon dates for shells recovered from glacimarine sediments and a dated tephra layer. Our revised chronology conflicts with earlier proposals that substantial dynamic ice caps persisted in Scotland between 14 and 13 ka, that large active glaciers probably survived throughout the Lateglacial Interstade and that ice extent was greater during the Older Dryas period than during the Younger Dryas Stade. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
843.
Taizishang slope of Qingjiang Reservoir in Huibei is within the range of atomization rainfall. The authors created the finite element model with ANSYS 10. 0 and used strength reduction FEM to calculate...  相似文献   
844.
We present a new regional calibration of the 10Be production rate from two well‐dated surfaces in southern Norway: a rock avalanche with 14C‐dated wood and a precisely dated Younger Dryas moraine. Calculated 10Be production rates are 4.26 ± 0.13 and 4.65 ± 0.14 at g?1 a?1 for the Lal/Stone and Lifton scaling models, respectively. Our regional production rate for southern Norway is 5% lower than the canonical global 10Be production rate with lower uncertainties. Our 10Be production rate agrees with regional 10Be production rates from north‐eastern North America and New Zealand. The 10Be production rate estimate presented here can be used to improve the precision and accuracy of exposure‐dated ice‐marginal features, as well as other surfaces, in northern Europe. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
845.
An irregular mesh model of the west coast of Britain is used to examine the sensitivity of tidal residuals to mesh resolution in the region. Computed residuals are compared with earlier published results determined with a high resolution (1 km grid) finite difference model of the eastern Irish Sea. Initial calculations show that tidal residuals are largest in nearshore regions particularly in the vicinity of headlands. Local refinement of the mesh in these regions leads to a more detailed picture of the flow field, particularly adjacent to the coast. Although large scale offshore features of the flow can be resolved using the high resolution finite difference model, such an approach leads to a “stair case” representation of the coastal boundary with an adjacent near coastal region of spurious tidal residuals. By using an irregular mesh that follows the coast, this effect is removed. In the Mersey river region the tidal residual is resolved with a mesh resolution of 120 m, although calculations show that its distribution is particularly sensitive to small scale features of the topography. A variable mesh that can accurately represent the lateral variations in river width and details of topography in both the nearshore and estuarine environment appears essential in modelling the coastal spread of freshwater plumes from rivers and pollutants discharged into the near coastal environment.  相似文献   
846.
通过高温固相反应制备了Er3+掺杂的nEr2O3:K2La2Ti3O10系列光催化剂,对样品进行了X射线衍射、扫描电镜、紫外可见吸收光谱和比表面积分析,并以染料降解考察了样品的光催化活性.研究表明.Er3+的适量掺杂抑制了K2La2Ti3O10粒径生长,增加了K2La2Ti3O10对太阳光的利用率.提高了K2La2Ti3O10的光催化活性.当n=0.003时,K2La2Ti3O10的光催化活性最大,在可见光和紫外光辎照下,可将多种染料水溶液降解.在可见光辐照下,其光催化活性优于市售的光催化剂TiO2(P25).  相似文献   
847.
成矿区划分为2个金成矿带,10个金矿田。构造控矿明显,岩浆活动与金成矿关系密切,成矿具长期性和滞后性,类型多样,矿床(点)空间分布集中,金与锑(汞)关系共存,找金潜力较大。  相似文献   
848.
张渊  张五荣  张洪喜 《世界地质》2010,29(3):408-412
10号脉是山东黄埠岭金矿区内的主要工业矿脉之一,产于玲珑花岗岩岩体中,受F10断裂构造控制。矿体呈柱状、脉状或透镜状产于矿脉内。矿石组成矿物有黄铁矿、自然金、银金矿、黄铜矿及石英等,矿石以交代溶蚀结构和脉状角砾状构造为主。矿化分4个阶段,含矿率为40%。矿化富集具有尖灭再现、侧伏和多期多阶段成矿等规律。10号脉深边部仍有成矿找矿远景。  相似文献   
849.
Quantifying erosion rates over various spatial and temporal scales across the Tibetan Plateau and its surrounding mountains is crucial to understanding the topographic evolution of the orogen. In this work, we report a new dataset of 10Be-derived basin-wide erosion rates from the main tributaries and streams draining the eastern Himalayan syntaxis. The 22 basin-wide erosion rates ranged from 78 ± 7 m Myear−1 to 3,490 ± 612 m Myear−1 across the study area. 26Al was contemporarily measured to evaluate the impact of sediment storage and non-steady-state erosion processes in the syntaxis region. The paired study of 10Be and 26Al reveals that several samples violated the steady-state erosion assumption and were compatible with the scenario of perturbation of reworked sediments or deeply sourced materials introduced by landslides. For most samples, deep-sourced materials with higher 26Al/10Be ratios were no longer perturbing the 10Be signals in river sediments. It is possible that the deep-sourced materials had been wiped out of the basins before the collection of samples in this work. However, the perturbation of reworked sediments was observed over a range of basin scales, limiting the use of a single sediment sample as a representative erosion product for upstream basins. Compared with tectonically stable regions, the incorporation of reworked fluvial sediments, deeply sourced materials or sub-glacial eroded materials into sampled sediments led to the decoupling between basin-wide erosion rates and topographic or climatic indices. Caution should be taken when deriving erosion rates from rapidly eroding regions with old, deeply buried sediments such as the eastern Himalayan syntaxis, where calculated erosion rates may be highly overestimated.  相似文献   
850.
Absolute gravity values were measured with a portable absolute gravimeter A10 in East Antarctica, for the first time by the Japanese Antarctic Research Expedition. This study aims to investigate regional spatiotemporal variations of ice mass distributions and associated crustal deformations around Syowa Station by means of repeated absolute gravity measurements, and we obtained the first absolute gravity value in Southern Langhovde on the Antarctic Continent. The average absolute gravity value at the newly installed benchmark AGS01 in Langhovde (obtained on 3 February 2012) was 982535584.2 ± 0.7 μgal (1 [μgal] = 1 × 10?8 [m/s2]), which was in agreement with the gravity values obtained by the past relative gravity measurements within 1 mgal. In addition, the average absolute gravity value obtained at AGSaux in Syowa Station was consistent with both previous absolute gravity values and those obtained by simultaneous measurements using an FG5 gravimeter, owing to adequate data corrections associated with tidal effects and time variations in atomic clock frequencies. In order to detect the gravity changes associated with the ice mass changes and other tectonic phenomena, we plan to conduct absolute gravity measurements at AGS01 again and at other campaign sites around Syowa Station as well in the near future, with careful attention paid to the impacts of severe environmental conditions in Antarctica on gravity data collection.  相似文献   
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