扩展的Helmert型方差分量估计公式

针对实用中某类观测值可能含有多个方差分量的情况,对现有Helmen型方差分量估计公式进行扩展,指出现有公式就是本文所推公式的特例。新公式从另外一个角度推导,理论和计算还表明它们与MINQUE公式和BIQUE公式的等价性,从而为不同方法的互检提供手段。     

中国北部地区沙漠鸣沙对比研究

鸣沙发声机制是一个长期悬而未决的问题。中国北部地质公园内的沙漠鸣沙地质遗迹沿北方沙漠弧形带分布,但较少被报道和研究。本文选取位于内蒙古、甘肃和新疆的沙漠鸣沙及哑沙,对其地貌特征﹑粒度组分和矿物成分进行了对比研究。结果表明鸣沙一般发育在新月型沙丘链或新月型沙丘上,紧邻湖泊或泉水,背风坡和迎风坡上都会发育鸣沙,但主要集中在背风坡,研究结果与马玉明提出的"共鸣箱"理论中的"响沙都发育在背风坡"不符;哑沙粒度明显较鸣沙粗,哑沙的平均粒径分布峰值集中在0.5φ~1φ,鸣沙粒径频率分布峰值集中在2φ~3φ;主要差别在于细砂和粗砂的组分,所有鸣沙中的细砂含量所占比例均高于52.012%,哑沙中的细砂含量低于0.881%;响沙中粗砂的含量均小于1.221%,哑沙中粗砂的含量大于48.091%。鸣沙和哑沙主要矿物成分都以石英和长石为主;鸣沙中含有高岭石,钠长石,微斜长石及方解石等,而哑沙中几乎未含这些次要矿物。本文结果表明,地貌特征和物质组成是区别鸣沙和哑沙的重要特征,对于研究鸣沙的成因具有参考价值。     

浅谈哈尔滨市城管部件普查与项目管理方法

以哈尔滨市城管部件普查为例,介绍了项目实施过程中有关质量控制与项目管理的方法及体会,为其他城市开展城管部件普查工作提供相关参考借鉴。     

Minimum mean squared error (MSE) adjustment and the optimal Tykhonov–Phillips regularization parameter via reproducing best invariant quadratic uniformly unbiased estimates (repro-BIQUUE)

In a linear Gauss–Markov model, the parameter estimates from BLUUE (Best Linear Uniformly Unbiased Estimate) are not robust against possible outliers in the observations. Moreover, by giving up the unbiasedness constraint, the mean squared error (MSE) risk may be further reduced, in particular when the problem is ill-posed. In this paper, the α-weighted S-homBLE (Best homogeneously Linear Estimate) is derived via formulas originally used for variance component estimation on the basis of the repro-BIQUUE (reproducing Best Invariant Quadratic Uniformly Unbiased Estimate) principle in a model with stochastic prior information. In the present model, however, such prior information is not included, which allows the comparison of the stochastic approach (α-weighted S-homBLE) with the well-established algebraic approach of Tykhonov–Phillips regularization, also known as R-HAPS (Hybrid APproximation Solution), whenever the inverse of the “substitute matrix” S exists and is chosen as the R matrix that defines the relative impact of the regularizing term on the final result. The delay in publishing this paper is due to a number of unfortunate complications. It was first submitted as a multi-author paper in two parts. Due to some miscommunication among the original authors, it was reassigned to one of the J Geod special issues, but later reassigned at this author’s request to a standard issue of J Geod. This compounded with a difficulty to find willing reviewers to slow the process. We apologize to the author.     

陕西省气候的主成分分析与区划

P个气候要素、n个站点的气候要素场,由主成分分析,可用前m个主成分反映气候要素场的主要气候特征,由各主成分的空间分布,可以分析各地的气候特征。据此,将陕西省划分为5个气候亚带11个气候区。     

基于图像处理单元的古建筑构件快速绘制

针对大规模古建筑三维模型场景渲染效率低的问题,该文提出了一种基于图像处理单元(GPU)的古建筑构件快速绘制的方法:根据复杂古建筑可分解为若干建筑构件的构造特点,把构件作为建模与绘制单元,以具有可编程的DirectX 11作为三维图形引擎,通过GPU物理层的曲面细分技术,实现旋转体建筑构件的精细表达;利用实例化技术,通过一次性创建构件几何缓存,实现大规模三维场景中重复建筑对象的高速绘制。实验结果表明:对于复杂古建筑物的大数据绘制,该方法与传统的CPU渲染方法相比,在渲染速度、可视化效果、大数据承载能力方面都具有显著的优势。     

蒋家沟流域坡面侵蚀特征实验研究

受流域内物质成分、气候条件和复杂侵蚀营力的影响,蒋家沟流域坡面侵蚀现象甚为严重。根据流域内坡面物质成分、气候、降雨等方面分析了发生坡面严重侵蚀的原因;并进行了大量的人工降雨侵蚀实验,分析降雨坡面产流产沙过程和特征。实验结果表明径流随降雨时间和降雨量的增加呈跳跃和波动性增加,泥沙含量随降雨时间增加而逐渐减小。     

Design flood estimation in ungauged catchments and statistical characterization using principal components analysis: application of Gradex method in Upper Moulouya

Design flood estimation in ungauged catchments is of great importance in hydrologic practice especially where there is no available data about streamflow. Except the watershed of Anseghmir who is equipped with a gauge station, all the other watersheds are ungauged catchments. The use of frequency analysis of series of rainfall and streamflow is very important for the characterization of the hydrologic resources of the Upper Moulouya. The region has a semiarid climate that requires a good knowledge of the watershed's potential water to assist policy makers in forecasting extreme events, managing water resources and decision making. The frequency analysis was used to determine the design flood of different return periods. The results obtained are used in Gradex method to estimate the hydrologic variables of each subcatchment of the Upper Moulouya. Once the hydrologic study is completed, a principal components analysis was made to highlight the affinities between the different subcatchments and to deduce the hydrologic and hydrographic parameters that better characterize them. Copyright © 2012 John Wiley & Sons, Ltd.     

汶川地震断裂带科学钻探工程2号孔350～800m井段的钻探泥浆气体组分变化

以汶川地震断裂带科学钻探工程(WFSD)2号孔350～800 m井段的钻探泥浆中某些气体组分测定数据,以及2009-10-10～2010-05-24钻孔附近断裂带范围内里氏震级ML≥3.5的目录、断裂带岩芯岩性为基础,探讨钻探泥浆脱气气体组分异常与构造环境、地震活动的关系。研究结果表明,660～680 m井段附近岩石破碎程度达到最大,各气体归一值也出现明显的正、负异常,得到的最大、最小值所对应的井段也是面波震级MS 3.0以上余震的频发处,气体异常多数出现在岩石的裂隙、破裂面、断层处。     

内蒙古准苏吉花铜钼矿区土壤热磁组分地球化学异常特征及意义

准苏吉花斑岩型铜钼矿床是内蒙古中北部新近发现的铜钼多金属矿床之一。这里对矿区地表土壤热磁组分中元素含量及异常特征进行了研究,结果表明元素异常在平面上出现明显的分带性,以地表矿化露头为中心向外依次为Mo-Cu-W-Te带、Ag-Bi-In-Zn-Cd带及As-Pb-Mn-Sb带,所有元素异常均包含在Fe2O3异常之内。通过土壤热磁组分地球化学测量,共圈出七个多元素组合异常,经野外异常查证,认为土壤热磁组分地球化学异常为有效的地质异常。因此,在风成沙覆盖区应用土壤热磁组分地球化学测量方法,配合多重分形(含量-求和法)和地质累积指数(Igeo)等统计方法,可最大限度消除风成沙干扰,快速、有效地确定异常下限,圈定多元素组合异常,提供有利找矿靶区。