海湾健康的概念和评估:数值模型在乐清湾健康评估中的作用

本文引入数值化海湾健康理论,提出三维数值化海湾健康评估方法以评估和预测海湾健康动态。选用五个指标组用以构建数值化海湾健康指标体系,包括地理指标组、水动力和泥沙动态指标组、生态指标组、水质指标组和社会经济指标组,用以评估自然过程和社会经济对海湾健康的影响。每一指标组中包括不同数量的二级指标。根据二级指标的不同重要性,运用层次分析法对其赋予不同的权重。指标的数据来源于三维数值模型和观测数据。三维数值模型能够为海湾健康评估提供更加全面、完整和详细的数据,并且可以提供预测数据。以乐清湾为例,数值化海湾健康评估方法成功应用于其健康评估过程。基于评估结果,乐清湾口门处表层水体的地理环境是健康的,水动力过程和泥沙动态过程属于亚健康状态,水质和生态环境处于不健康状态。总体而言,乐清湾的海湾健康评估结果为亚健康状态。     

地面三维激光扫描仪的精度评定方法研究

地面三维激光扫描仪所获取的点云定位精度,在实际应用中需要便捷的精度评价手段。本文研究利用精密仪器建立高精度的室内检测场,用Trimble-TX8型三维激光扫描仪进行扫描,通过与高精度控制点对比,快速地对扫描仪的测距、测角、点位精度进行分析和评定,得到仪器实际环境下的测量精度。本研究亦可为其他三维激光扫描仪的精度评定提供经验和借鉴。     

基于三维地理信息技术的电力巡线应用研究

传统的人工巡视以及二维图形表达已经无法适应经济的快速增长、社会应急要求的提高对电力网络巡检与管理的需要。随着计算机、数据采集等关键技术的不断进步,三维地理信息技术在电网管理中得到了广泛地应用。结合相关工程实践,基于三维地理信息技术,本文研究了一整套满足电力巡线、管理的构建方法与应用流程。通过该技术应用,可为电力巡线工作提供科学、直观的数字化支持,从而服务电力网络的安全运行与高效管理。     

单幅干涉图像提取震间形变场模拟研究

针对活动断层震间InSAR形变场提取中存在SAR观测数据不足、轨道误差难以合理去除的问题,该文进行了利用单幅InSAR图像提取震间形变场的模拟研究:考虑到InSAR图像中轨道误差和震间形变场的空间分布特征,利用一次多项式模型和深部滑动模型模拟了100组叠加的InSAR形变场;然后采用直接恢复震间形变场、先分离轨道误差再恢复震间形变场、一步法分离轨道误差与恢复震间形变场3种方法对模拟的震间形变场进行了恢复实验。结果表明,基于单幅InSAR图像,利用一步法能够较为准确地恢复震间形变场。     

Morphology and crustal structure of a small transform fault along the Mid-Atlantic Ridge: The Atlantis Fracture Zone

The Atlantis Fracture Zone (30° N) is one of the smallest transform faults along the Mid-Atlantic Ridge with a spatial offset of 70 km and an age offset of ~ 6 Ma. The morphology of the Atlantis Fracture Zone is typical of that of slow-slipping transforms. The transform valley is 15–20 km wide and 2–4 km deep. The locus of strike-slip deformation is confined to a narrow band a few kilometers wide. Terrain created at the outside corners of the transform is characterized by ridges which curve toward the ridge-transform intersections and depressions which resemble nodal basins. Hooked ridges are not observed on the transform side of the ridge-transform intersections. Results of the three-dimensional inversion of the surface magnetic field over our survey area suggest that accretionary processes are sufficiently organized within 3–4 km of the transform fault to produce lineated magnetic anomalies. The magnetization solution further documents a 15-km, westward relocation of the axis of accretion immediately south of the transform about 0.25 Ma ago. The Atlantis Transform is associated with a band of high mantle Bouguer anomalies, suggesting the presence of high densities in the crust and/or mantle along the transform, or anomalously thin crust beneath the transform. Assuming that all the mantle Bouguer anomalies are due to crustal thickness variations, we calculate that the crust may be 2–3 km thinner than a reference 6-km thickness beneath the transform valley, and 2–3 km thicker beneath the mid-points of the spreading segments which bound the transform. Our results indicate that crustal thinning is not uniform along the strike of the fracture zone. Based on studies of the state of compensation of the transform, we conclude that the depth anomaly associated with the fracture zone valley is not compensated everywhere by thin crust. Instead, the regional relationship between bathymetry and gravity is best explained by compensation with an elastic plate with an effective thickness of ~ 4 km or greater. However, the remaining isostatic anomalies indicate that there are large variations away from this simple model which are likely due to variations in crustal thickness and density near the transform.     

中国沿海管体星虫属(星虫动物门)的研究

报道作者采自我国沿海管体星虫属共计4种。其中富岛管体星虫Siphonosomafunafuti(Shipley)在我国是首次记载。     

Morphology of the Blanco Transform Fault Zone-NE Pacific: Implications for its tectonic evolution

The right-lateral Blanco Transform Fault Zone (BTFZ) offsets the Gorda and the Juan de Fuca Ridges along a 350 km long complex zone of ridges and right-stepping depressions. The overall geometry of the BTFZ is similar to several other oceanic transform fault zones located along the East Pacific Rise (e.g., Siquieros) and to divergent wrench faults on continents; i.e., long strike-slip master faults offset by extensional basins. These depressions have formed over the past 5 Ma as the result of continual reorientation of the BTFZ in response to changes in plate motion. The central depression (Cascadia Depression) is flanked by symmetrically distributed, inward-facing back-tilted fault blocks. It is probably a short seafloor spreading center that has been operating since about 5 Ma, when a southward propagating rift failed to kill the last remnant of a ridge segment. The Gorda Depression on the eastern end of the BTFZ may have initially formed as the result of a similar occurrence involving a northward propagating rift on the Gorda ridge system. Several of the smaller basins (East Blanco, Surveyor and Gorda) morphologically appear to be oceanic analogues of continental pull-apart basins. This would imply diffuse extension rather than the discrete neovolcanic zone associated with a typical seafloor spreading center. The basins along the western half of the BTFZ have probably formed within the last few hundred thousands years, possibly as the result of a minor change in the Juan de Fuca/Pacific relative motion.     

The Kefalonia Transform Zone (offshore Western Greece) with special emphasis to its prolongation towards the Ionian Abyssal Plain

Information concerning two seismic lines, the first located northwest of the Lefkada Island and the second from the deep Ionian basin to the gulf of Patras, is used to trace the Kefalonia Transform Zone (KTZ) and to explore its relation with the sedimentary sequences and the deeper geologic structures in the study area. In addition, sea bottom topography and fault plane solutions are combined in order to explore the prolongation of the KTZ into the Ionian Abyssal Plain (IoAP) and to describe its properties. The boundary between the subduction of the eastern Mediterranean oceanic crust under the overriding continental crust and the KTZ is well constrained by the seismic data in association with seismicity and regional stress field. The southern prolongation of the KTZ is located in the IoAP towards the direction between Kefalonia and Zakynthos Islands at depth greater than 15 km. The southern part of the KTZ exhibits a strike–slip motion with a thrust component according to fault plane solutions of moderate and strong earthquakes. The seismic section mostly confirms the existence of the thrust component and gives information about the tectonic status east and west of the KTZ.     

基于2,3维混合的多层次地籍变更模式研究

随着城市多元、立体化的深入发展,土地空间权利从平面向立体的转变,土地和建筑物的变更越来越频繁。因此,以土地地表权属为核心、以地块为基础的传统2维地籍已不能满足实际应用需求,3维地籍的建立是地籍发展的必然趋势。然而,就现有的法律和技术而言,实现全3维地籍存在一定的难度,实现3维地籍变更是有困难。基于此,本文讨论了如何在2维地籍的基础上划分得到3维地籍的基本单元,并根据地籍变更的方法和分类,提出了六类地籍变更事件以及事件关联关系,在此基础上提出基于基于2,3维混合的多层次地籍变更模式。最后,以实例验证,本文的方法能有效地结合2,3维地籍系统,实现2维地籍到3维地籍平滑、无损的过渡,具有较好的实用性。     

金平白马寨铜镍矿床地球物理成矿预测模式

通过对大量地质及物化探资料分析,运用地质学、矿床学以及地球物理勘探学的基本理论和方法,分析了金平白马寨铜镍矿床的地质与地球物理特征,从而提出了本区铜镍矿床为岩浆熔离脉冲贯入型矿床和“三高一低”,即重力高、磁力高、极化率高、电阻率低的地球物理成矿预测模式．