大屯矿区测量控制网沿革与分析     

王晓明 《北京测绘》2010,(3):69-73

大屯矿区建矿筹备到今已近40多年,矿区测量控制网为矿区的建设发展提供准确、可靠的基础数据,基本满足了矿区矿井建设施工的需要。随着经济发展及矿区建设的深入,矿区测绘工作者的新老更替,对原有矿区测量控制网的基本情况,控制网的演变、了解已知之甚少。针对矿区测量控制网现状分析、总结,并就矿区控制网(相对独立系统)提出建议。  相似文献   

生物扰动下海底沉积物-水界面溶解氧二维观测方法     

李栋  姜子可  于新生  黄颂 《海洋科学》2014,38(5):89-94

沉积物-水界面(SWI)是生物地球化学循环的主要界面,界面上溶解氧(DO)的分布实时测量对于了解生物扰动的复杂作用和生物地球化学循环过程有着重要意义。为了探索生物扰动作用对SWI微尺度溶解氧二维分布的影响作用,本文以八乙基卟啉铂为荧光指示剂,掺杂香豆素(Macrolex Yellow10GN)作为荧光素能量供体,以聚苯乙烯为基质制作了光学平面传感膜。以发光二极管(LED)为激励光源,结合彩色相机,构建了基于比率法的二维溶解氧观测系统,系统能够以0.36 mm的空间分辨率对SWI的溶解氧分布连续观测,实验室内的模拟实验结果表明,底栖沙蚕掘穴扰动可使局部沉积物溶解氧质量比提高3~4?g/g。该研究填补了国内基于比率法的平面光学溶解氧传感器研究领域的空白。  相似文献   

һ��ƽ����ĵ���ȡ�㷨     

朱宁宁  卢小平  李向阳  武永斌 《大地测量与地球动力学》2014,34(3):173-177

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Microchemistry and microstructures of hydrothermally altered shock-metamorphosed basement gneiss,Woodleigh impact structure,Southern Carnarvon Basin,Western Australia     

A. Y. Glikson  S. Eggins  S. D. Golding  P. W. Haines  R. P. Iasky  T. P. Mernagh 《Australian Journal of Earth Sciences》2013,60(4-5):555-573

  相似文献   

西藏贡觉县各贡弄铜金矿地质特征及成因探讨     

王伍四  李文庆 《安徽地质》2013,(2):104-107

本文对西藏贡觉县各贡弄铜金矿区铜金矿产出地质特征进行介绍,并对其与地球物理、地球化学的关系予以阐述,指出该矿区与西藏玉龙斑岩铜钼矿同处一带上,典型面状蚀变特征明显,富集的Au、Ag、Cu、Pb等亲Cu元素来自大小不等的斑岩岩株,显示本区有进一步寻找斑岩型铜金矿的潜力。  相似文献   

声脉冲在液态平面层系上反射的数值计算     

王恕铨  林俊轩 《中国海洋大学学报(自然科学版)》1988,(4)

对入射平面脉冲声波,由其频谱和层系的反射系数可通过数值计算得到其在液态平面层系上的反射波。这对室内与海上声学实验及某些类型的水声仪器设备的研制都是一个有用的辅助手段。本文举出了一些计算的例子。  相似文献   

Oxygen depletion and phosphorus release following flooding of a cultivated wetland area in Denmark     

Nina L. Grunth  Louise Askaer  Bo Elberling 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):17-25

Geografisk Tidsskrift, Danish Journal of Geography 108(2):17–25, 2008

The rewetting of altered wetlands is becoming increasingly widespread. When flooding cultivated soils, the oxygen (O₂) availability is reduced, subsequently, ferric hydroxides can dissolve and associated inorganic phosphorus (P) will be mobilized. This study shows the temporal and spatial dynamics of O₂ depletion following flooding using planar optodes and the subsequent release of Fe and P in two depth intervals in an experimental column set-up. The column was kept flooded for 48 days and thereafter partly drained and flooded again. Results document that large amounts of P (0.2 t P ha-¹) have accumulated in the present plough-layer (Ap) during the last 22 years, which represent roughly 15% of the present inorganic P stock in the Ap. As a result of flooding, fully anoxic conditions were observed within 3 days (within 10 h in Ap) and concentrations of dissolved Fe and P in the soil solution increased simultaneously after 7 days of flooding. Thus, P reaction kinetics was markedly delayed as compared to O₂ availability. P concentrations in soil water afterflooding (up to 0.15 mg L^?1) accounted for only 0.034% of the inorganic P stock in the Ap which is a significantly smaller fraction of the potential P-release as compared to previous investigations.

This is considered a result of only a minor fraction of the total inorganic P being directly associated with ferric hydroxides and thereby sensitive to short-term anoxic conditions as well as differences in the methodology used in this study (soil/water ratio). Finally, reactions releasing Fe and P were noted to be partly reversible upon draining.  相似文献   

沈阳市阳光港湾建筑群基坑降水施工研究     

赵立杰  张东岳 《中国煤炭地质》2010,(9):32-34,75

沈阳市阳光港湾建筑群高层建筑采用筏板基础,多层建筑采用人工挖孔灌注桩基础,在基础施工时,均需进行相应的降水工作。采用了分期降水的施工方法,首期降水施工是在分析场地水文地质条件的基础上,利用稳定流"大井法"预算基坑的涌水量,布置了9口井,使基坑周边的1#、2#、3#、4#观测孔水位均下降至5.11m,基本上达到了首期的降水的目的;第二期降水是利用首期降水观测的水位资料,采用稳定流干扰井群计算公式对场区地下水位进行了预报,重新设计了3口井。12口井全部投放使用后,测得稳定排水量为43 000m3/d,并形成了以基坑为中心的地下水降落漏斗,降水效果明显。此经验值得同类工程借鉴。  相似文献   

运用迭代FFT算法优化平面稀疏阵列     

张飞  黄伟  陈客松 《全球定位系统》2012,37(2):38-42

介绍了一种基于迭代FFT算法的优化方法来实现平面稀疏阵列的峰值旁瓣电平优化,给出了详细的优化步骤。在给定的旁瓣约束条件下,利用阵列因子与阵元激励之间存在的傅里叶变换关系,对不同的初始随机阵元激励分别进行迭代循环,可以降低稀疏阵列的旁瓣电平。在迭代过程中,根据稀疏率将阵元激励按幅度大小置1、置0来完成阵列稀疏。仿真实验证明了该方法的高效性和稳健性。  相似文献   

Effect of the duration and direction of storm movement on planar flow with full and partial areal coverage     

Vijay P. Singh 《水文研究》2002,16(17):3437-3466

Using kinematic wave equations, analytical solutions are derived for flow resulting from storms moving either up or down the plane and covering it fully or partially. By comparing the flow resulting from a moving storm with that from a stationary storm of the same duration and areal coverage, the influence of storm duration, direction and areal coverage is investigated. It is found that the direction, duration and areal coverage of storm movement have a pronounced effect on the discharge hydrograph. The runoff hydrographs resulting from storms moving downstream are quite different from those from storms moving upstream. Likewise, the areal coverage of the storm has a pronounced effect on the runoff hydrograph. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献