Dynamic Response to Seismic Waves at the Shallow Slope Supported by Bolts

In the soil slope supported by bolts, longitude waves instead of transverse waves, generated by earthquakes, first reach the slope surface. With the dynamic response of the P (pressure) wave along the anchorage structure, first, a theoretical study was conducted to investigate the propagation characteristics of the interference superposition, generated by the SV (shear-vertical) and the P waves. The SV wave was formed by the wave, originating from the bottom and reflected from the free surface of the slope, whereas the latter was the incident P wave, propagating in the slope. In addition, the structural measures, restraining the seismic wave, and the characteristics of the restraint effect at the free segment of the bolt were investigated. According to the wave-way difference between the incident P wave and the reflected SV wave, the minimum critical slope angle, influenced by the interference at the shallow slope, and the maximum influencing depth of the dynamic response, acting vertically to the slope surface, were obtained. The results indicate that the maximum influencing depth linearly correlated with the slope angle. Furthermore, based on the propagation characteristics of the P wave along the bolt, and the coupled relation between the wave length and the anchorage design parameters, the axial acceleration of the wave propagating along the bolt axis was obtained. Then, the theoretical length of the anti-seismic bolt, subjected to seismic waves, and the compensation force of the anchorage structure were obtained. Finally, a numerical study, based on FlAC3D, properly verified the theoretical conclusions.     

土壤入渗对阜新市北部浅层地下水总硬度影响的淋滤实验

本次室内土柱淋滤实验通过改变Na~+、H~+、NH_4~+浓度来模拟现实生活中不同浓度的生活污水、酸雨及农业施肥灌溉对浅层地下水总硬度的影响过程。实验结果表明淋滤液浓度越高,所对应的淋出液的总硬度峰值就越高。相同浓度的Na~+、H~+、NH_4~+进行土柱淋滤实验时,NH_4~+所对应的淋出液总硬度的峰值最大,H~+次之,Na~+最小且NH_4~+所对应的整个实验用时最短,在相同浓度单一离子作用下NH_4~+对浅层地下水硬度的影响更加明显。     

Disciplinary System and Development Strategy for Eco-hydrology

Eco-hydrology is a new discipline developed in recent decades. It is of great significance to accelerate and promote the development of eco-hydrology subject by constructing a perfect discipline system and formulating future development strategies. By reviewing a large number of literatures, this paper systematically combed and expounded the development and evolution of the eco-hydrology, which can be divided into five stages, the embryonic period of eco-hydrology (1970-1986), formulation terminology and the initial exploration period of eco-hydrology (1987-1991), discipline establishment and the initial development period of eco-hydrology (1992-1995), the rapid development period of eco-hydrology (1996-2007) and the improvement period of eco-hydrology (2008-present). Based on the analysis of the development of eco-hydrology, the disciplinary system of eco-hydrology was proposed as a framework of “theory-method-practice-branch discipline”. Finally, combined with the authors’ understanding, this paper put forward the development strategy system of the eco-hydrology, including the disciplinary research plan, the key research project, the country’s major demand, the discipline construction and the international cooperation, which will provide support for the promotion and establishment of a sound disciplinary system of eco-hydrology.     

一种基于属性值变化程度定权的聚类算法

针对经典K-means聚类算法以欧氏距离作为相似度判断法则进行聚类划分,而未考虑聚类对象的各属性值对聚类划分的影响程度存在差异的问题,该文提出了一种基于属性值变化程度定权的聚类算法。通过采用Iris dataset数据进行实验,该算法相对于其他聚类算法获得了更好的聚类效果,且该算法适用于生物物种分类、遥感影像识别等工作领域,能提高聚类运算的精准度。     

大范围复杂三维场景并行绘制实时帧同步技术

针对复杂三维模型在实时绘制过程中的帧同步策略,该文提出改进。基于Windows集群开发了一种sort-first数据分布式体系结构的并行图形绘制系统;基于缓存交换技术提出一种多路并行的帧同步算法来提高集群的通信效率。在Windows集群系统上进行了验证实验,结果表明:(1)该算法较大程度地提高了集群的帧同步性能并缩短了同步重建时间;(2)集群并行系统有效地完成了大范围复杂三维GIS场景的流畅绘制显示。     

An enhanced approach for surface flow routing over drainage‐constrained triangulated irregular networks

The accuracy and efficiency of the simulations in distributed hydrological models must depend on the proper estimation of flow directions and paths. Numerous studies have been carried out to delineate the drainage patterns based on gridded digital elevation models (DEMs). The triangulated irregular network (TIN) has been increasingly applied in hydrological applications due to the advantages of high storage efficiency and multi‐scale adaptive performance. Much of the previous literature focuses mainly on filling the depressions on gridded DEMs rather than treating the special cases in TIN structures, which has hampered its applications to hydrological models. This study proposes a triangulation‐based solution for the removal of flat areas and pits to enhance the simulation of flow routing on triangulated facet networks. Based on the drainage‐constrained TIN generated from only a gridded DEM by the compound point extraction (CPE) method, the inconsistent situations including flat triangles, V‐shape flat edges and sink nodes are respectively identified and rectified. The optimization algorithm is an iterative process of TIN reconstruction, in which the flat areas are generalized into their center points and the pits are rectified by embedding break lines. To verify the proposed algorithm and investigate the potential for flow routing, flow paths of steepest descent are derived by the vector‐based tracking algorithm based on the optimized TIN. A case study of TIN optimization and flow path tracking was performed on a real‐world DEM. The outcomes indicate that the proposed approach can effectively solve the problem of inconsistencies without a significant loss in accuracy of the terrain model.     

北秦岭西段早侏罗世A型花岗岩及其地质意义

本文通过岩相学、岩石地球化学、锆石U?Pb定年和Lu?Hf同位素组成分析等方法,对出露于北秦岭西段宝鸡岩体王家山一带的黑云母花岗岩和其中的包体进行了研究。结果表明,该花岗岩形成时代为187±2 Ma,属于高钾钙碱性—钾玄岩系列岩石,富集Rb、Th、U等大离子亲石元素以及Nb、Zr和Hf等高场强元素,亏损Ba、Sr和Eu,具有高的全岩锆石饱和温度(825℃~838℃),显示A型花岗岩特征,形成于造山后的板内环境,可能为秦岭岩群副变质岩与安山质岩石部分熔融的产物。暗色包体显示塑性流变特征,具有岩浆结构,发育针状磷灰石和具有复杂成分环带的更长环斑结构长石,是幔源岩浆注入酸性岩浆发生混合作用的产物,形成时代为191±2 Ma,其锆石Hf同位素组成变化范围较大,εHf(t)值介于-11.26~-2.51,主要为富集地幔部分熔融产物。综合本文及前人已有研究结果,认为~190 Ma的早侏罗世早期秦岭地区早中生代碰撞造山过程已经结束,区域开始逐渐进入板内伸展构造演化阶段。     

陇中盆地及周边地区主夷平面演化与高原隆升

陇中盆地及周边地区是青藏高原向北东方向扩展的最前缘部位,其地貌演化过程的研究对于深入理解高原的隆升与扩展过程具有重要意义。鉴于夷平面在探讨高原隆升年代、幅度和过程方面的可靠性,首先总结陇中盆地及周边地区夷平面相关研究的前期成果,并结合最新年代数据,确定了不同区域主夷平面的发育和解体年代;再利用古河道拟合等方法定量评估了相关夷平面的隆升量;最后探讨了主夷平面的性质及其隆升过程。研究发现,陇中盆地及周边的地区的高海拔低起伏地貌面是被抬高的先存夷平面;不同区域主夷平面的发育与解体时间整体同步,它们自晚渐新世开始发育,并于晚中新世8~6 Ma左右解体;模拟结果表明,美武高原主夷平面自晚中新世以来相对陇中盆地隆升了约1 400~1 600 m,并且早更新世以来的隆升速率明显大于晚中新世-早更新世时期。     

下庄竹山下铀矿床黄铁矿元素地球化学特征及其表征意义

竹山下铀矿床是粤北下庄铀矿田内大型铀矿床之一,铀矿化类型为"交点"型和硅化带型。在详细的野外地质调查基础上,对竹山下铀矿床4种不同类型黄铁矿进行元素含量分析及硫同位素测试,结果表明:"交点"型矿石中黄铁矿相对富集Pb、 Cu、 Co、 As、 Ni、 Se、 Bi、 U、 Sb、 Zn等微量元素;"交点"型铀矿化形成于中深部高温环境,成矿热液具有地幔流体特征,成矿过程硫来源与该区花岗岩中黄铁矿的硫来源一致或者相似,花岗岩中的黄铁矿可能为该期成矿事件的产物;竹山下矿床在垂向上表现出越往深部硫逸度越低的特征;"交点"型和硅化带型中黄铁矿具有相似的微量元素配分曲线,表明二者具有相同的成矿热液来源,且与辉绿岩中黄铁矿配分曲线相似,表明该区成矿热液具有深源性。