内蒙古科尔沁右翼中旗敖兰三队侵入体年龄及地球化学特征

内蒙古科尔沁右翼中旗敖兰三队侵入体的同位素年代学及岩石地球化学研究表明,敖兰三队侵入体巨晶正长花岗岩具有低Sr、高Yb型花岗岩特征,其LA-ICP-MS锆石~(206)Pb/~(238)U年龄加权平均值为220±1Ma,表明该侵入体是晚三叠世早期侵位形成的。岩石高硅、富碱、高铁镁比、贫钙、贫镁和低钛;稀土元素配分曲线呈现"海鸥式"分布特征,显示强烈的Eu负异常。微量元素特征显示较低的Sr、Ba含量,较高的Yb、Zr和Y含量,在微量元素原始地幔标准化蛛网图上显示明显的Sr、Ba和Ti的负异常。岩石具有高的Rb/Sr和Rb/Nb,显示出壳源岩浆的成分特征。综合分析表明,本区巨晶正长花岗岩为低压下地壳部分熔融的产物。根据(Y+Nb)-Rb、(Yb+Ta)-Rb、Nb-Y-Ce三角图解,并结合区域构造演化,认为巨晶正长花岗岩形成于造山后伸展的构造环境。在中—晚三叠世,内蒙古科尔沁右翼中旗地区构造体制经历了重要的转变,由挤压体制转变为造山后软流圈上涌、岩石圈减薄。     

Fitting boxes to Manhattan scenes using linear integer programming

We propose an approach for automatic generation of building models by assembling a set of boxes using a Manhattan-world assumption. The method first aligns the point cloud with a per-building local coordinate system, and then fits axis-aligned planes to the point cloud through an iterative regularization process. The refined planes partition the space of the data into a series of compact cubic cells (candidate boxes) spanning the entire 3D space of the input data. We then choose to approximate the target building by the assembly of a subset of these candidate boxes using a binary linear programming formulation. The objective function is designed to maximize the point cloud coverage and the compactness of the final model. Finally, all selected boxes are merged into a lightweight polygonal mesh model, which is suitable for interactive visualization of large scale urban scenes. Experimental results and a comparison with state-of-the-art methods demonstrate the effectiveness of the proposed framework.     

廉价的海洋学资料收集者--海洋动物

本文简要介绍了利用海洋动物获取海洋学资料的方法——“生物自律式”海洋学资料收集。利用海洋动物的自律式取样设备，成本非学低廉。海豹、金枪鱼、旗鱼、鲨、海岛和鲸等，将来都可予以利用。     

造成我国北方暴雨的热带气旋天气学特征分析

本文利用１９６０～１９９４年台风年鉴资料，定义进入３０°Ｎ以北、１２５°Ｅ以西的热带气旋为影响北方热带气旋。根据定义普查，３５年中共有６３个造成北方暴雨，年均１．８个。我们把影响北方暴雨的６３个热带气旋根据后期移动路径的不同划分为６类，以５００ｈＰａ高空图为基础，分析西风带和副热带系统的特征，给出了各类热带气旋在影响北方前２４ｈ副热带和西风带系统的异同。     

Two Necessary Conditions for the Glacial-Interglacial Cycles in the Quaternary

Milankovitch Theory shows that glacial-interglacial cycles in the Quaternary are related to the variation of solar insolation forcing linked to the earth's astronomical parameters.However,the summer insolation at northern high latitudes,usually considered as the main external forcing for the ice age as Milankovitch pointed out,is marked by the 19- and 23-ka precession periodicities,which is not consistent with the glacial-interglacial cycles.On the other hand,recent studies indicate that the annual mean ...     

Separating climate change and human contributions to variations in streamflow and its components using eight time‐trend methods

Separating impacts of human activities and climate change on hydrology is essential for watershed and ecosystem management. Many previous studies have focused on the impacts on total streamflow, however, with little attentions paid to its components (i.e., baseflow and surface run‐off). This study distinguished the contributions of climate change and human activities to the variations in streamflow, baseflow, and surface run‐off in the upstream area of the Heihe River Basin, a typical inland river basin in northwest China, by using eight different forms of time‐trend methods. The isolated contributions to streamflow variation were also compared with those obtained by two Budyko‐based approaches. Our results showed that the time‐trend methods consistently estimated positive contributions of climate variability and human activities to the increases in streamflow and its components but with obviously varying magnitudes. With regard to streamflow, the time‐trend method double‐mass‐curve–Wei, with a physical basis, produced a reasonable smaller contribution of human activities than climate changes, inconsistent with the Budyko‐based approaches. However, all the other time‐trend methods led to contrary results. The contributions to baseflow variation diverged more significantly than those to streamflow and surface run‐off, ranging from 24% to 92% for human activities and from 8% to 76% for climate variability. In terms of surface run‐off, most of the time‐trend approaches produced smaller contributions of human activities (ranging from 21% to 49%) than climate change. The uncertainties associated with the various time‐trend approaches and the baseflow separation algorithm were revealed and discussed, along with some recommendations for future work.     

Integrated edge detection and terrain analysis for agricultural terrace delineation from remote sensing images

ABSTRACT

Agricultural terraces are important for agricultural production and soil-and-water conservation. They comprise treads and risers that require manual construction and maintenance. If managed improperly, risers will collapse, causing soil loss, gully erosion, and cultivation threats. However, mapping terrace risers remains a challenge. This study presents a novel approach to automatically map terrace risers by combining remote sensing images and digital elevation models (DEMs). First, a terraced hillslope was extracted via a hill-shading method and edges in the image were detected using a Canny edge detector. Next, the DEM was used to generate the contour direction, and edges along this direction were searched and coded as candidate terrace risers via directional detection. Finally, the results of directional detection and the edge image obtained from the Canny detector were overlaid to backtrack complete terrace risers. The approach was validated using four study areas with different topographic characteristics in the Loess Plateau, China. The results verify that the approach achieves outstanding performance and robustness in mapping terrace risers. The precision, recall, and F-measure were 90.81%–97.57%, 88.53%–94.10%, and 90.13%–95.80%, respectively. This approach is flexible and applicable with freely available images and DEM sources.     

Flood vulnerability assessment using the triangular fuzzy number-based analytic hierarchy process and support vector machine model for the Belt and Road region

Natural Hazards - Flood is one of the most serious natural disasters in the world. Flood losses in the developing countries throughout the Belt and Road region are more than twice the global...     

论冰川颤痕

颤痕是冰川作用地区由冰川携带岩屑做周期性或间歇性运动在冰床基岩和冰碛石表面形成的新月形或弧形破裂形态,特征尺度一般不大于1 m。其主要形成机制类似Riedel构造模式中的（R）剪切破裂和（T）拉张破裂,且遵循脆性破裂原理。根据国内外文献报道和野外考察,从术语学角度将冰川颤痕分为狭义和广义两种。广义冰川颤痕,包括曲锥形擦口（狭义颤痕）、半月形裂口、新月形凿口、新月形裂纹和新月形断口5种。测量统计结果显示,23组新月形断口的排列间距,KS和JB检验均符合正态和伽玛分布（置信度95%）,与岩石节理（破裂）的间距特征一致;25组新月形凿口和35组新月形裂纹的排列间距,KS检验符合正态分布和伽玛分布,JB检验不符合正态分布（置信度95%）。证明颤痕在空间分布上大体保持相等的破裂间距,基本符合饱和模式理论。颤痕的定向性、成组特征具有明确的环境意义,与擦痕、擦面的地貌组合是重要的冰川遗迹判别标志。缺少冰蚀地貌组合的孤立“颤痕”,不具有指示冰川作用的价值。近年报道的山东鲁山没有“颤痕”等冰川遗迹。     

麦饭石促进异养反硝化去除水中硝酸盐的研究

微生物异养反硝化技术是市政污水处理中广泛应用的技术,但在实际应用中,微生物活性易受冲击负荷、重金属胁迫等环境条件影响,使出水效果不稳定。麦饭石作为一种天然硅酸盐矿物,能有效提高微生物活性及对环境胁迫的抗性,可以将其应用于微生物污染治理领域。通过批实验研究麦饭石的剂量、处理方式对异养反硝化的促进作用并探究麦饭石作用于微生物的机理。结果表明,麦饭石的投加剂量和处理方式均显著影响了微生物对硝酸盐的去除效果。硝酸盐去除率与麦饭石投加量呈正相关,麦饭石投加量为350 g/L时硝酸盐去除率可达96%,未添加麦饭石的空白组硝酸盐去除率仅为25%;处理方式会影响麦饭石对反硝化过程的强化作用,研磨后过200目筛的麦饭石在投加量<150 g/L时具有优势,投加量继续增大后,未经处理的麦饭石表现出更强的反硝化促进作用。进一步采用未经处理的麦饭石、研磨后过200目筛麦饭石及球磨麦饭石浸出液进行反硝化的促进实验及微生物毒性实验探究麦饭石作用于微生物的机理。实验结果表明,麦饭石浸出液能够提高微生物的活性及对环境胁迫的抗性,影响麦饭石生物促进作用的主要因素为其溶出微量元素的成分及浓度。本研究为天然矿物麦饭石应用于微生物污染治理提供理论依据和实际应用价值。