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航空重力测量的历史回顾 总被引：1，自引：0，他引：1
在本世纪５０年代末到６０年代,首次报导的航空重力测量尝试,是利用固定翼飞行器所进行的可行性试验。仪器系统是由海上重力仪、摄影测量照像机和定位多卜勒雷达,以及一些仅用于测定高度变化的沸点测高器组成的。试验的几条测线经过相对较高的地形区域。一般情况下重力仪运行正常,但该系统在对航空能力的控制和测量,以及计算艾维改正、飞行稳定性对于精确测量飞行器的垂向运动中受到限制。这些试验表明,航空重力测量可获得±１０×１０－５ｍ／ｓ２的精度。１９６５年１月,空军的剑桥研究实验室开始了一项深入细致的计划,对现有的和… 相似文献
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本文研究了An(219Rn)的野外现场测量技术,提出了原地测量法和桶中测量法.列举了在已知矿床上实测的一些结果,讨论了该技术的应用前景. 相似文献
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《勘察科技》2006,(4):33-33
史华林同志，1991年7月毕业于南方冶金学院工程测量专业，高级工程师、测绘分院总工程师。参加工作以来，负责组织实施了各种类型的测绘工程项目，其中有公路带状地形测量及控制测量、公路中线放线测量、地下管线测量、水下地形测量、GPS控制测量、二等水准测量、滑坡变形测量、建构筑物沉降观测、数字化地形测量、输电线路断面测量、城镇规划地形测量、建设拟用土地勘测定界测量等项目。曾负责云南临沧机场工程测量项目中的GPS测量方面工作，该项目获云南省2001年度优秀工程勘察二等奖；负责的兰坪县城规划数字化地形测量项目，获2004年有色系统第九届优秀工程勘察三等奖。 相似文献
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岩石侵蚀速率测算方法研究综述及展望 总被引：1，自引：0，他引：1
讨论了目前应用比较广泛的几种测算岩石侵蚀速率的方法,将目前岩石侵蚀速率测算方法分为2类:一类为质量测算法,包括公式计算法、流域水化学监测法、样品称重法;另一类为几何测算法,包括微侵蚀测量仪法、对比计算法和宇宙成因核素法.探讨了各方法的测算原理、优缺点及其适用领域,质量测算法中的公式计算法和流域水化学监测法比较适用于大面积的国土监测工作;样品称重法和3类几何测算法适用于尺度较小的地学研究和文物保护、工程技术等应用领域.最后,总结了岩石侵蚀速率研究者和案例地的地理分布规律,并对岩石侵蚀速率测算研究进行了展望. 相似文献
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Transformation of debris flows into turbidity currents: mechanisms inferred from laboratory experiments 总被引：6，自引：0，他引：6
Three sets of lock exchange experiments were run to look at the generation of turbidity currents from debris flows. The flows ranged from reasonably dilute (4% volumetric concentration) to dense (40% volumetric concentration) with cohesive, non-cohesive and mixed cohesive/non-cohesive sediment. Concentration was measured at one height using an Ultrasonic High Concentration Meter. Velocity was measured using Ultrasonic Doppler Velocimetry Profiling at 10 different heights in each run. The resulting flows range from plug flows to well mixed flows. Comparison of the concentration profiles, velocity time–height plots and vertical profiles of downstream velocity and root mean square velocity showed several different transformation mechanisms. Depending on the concentration and composition of the flow, transformation took place through one or more of the following processes: erosion of material from the dense mass, breaking apart of the dense underflow, breaking of internal waves and turbulent mixing. The extent of transformation depends on the viscosity and density of the flow. Initially very dense and viscous flows experience minor transformation only at the surface, resulting in a dilute turbidity current. Flows that are initially not so dense and viscous are churned up entirely, undergoing the different transformation processes. For these flows, transformation processes work throughout the entire flow, not just at the surface. Transformation of the less-dense flows is efficient with all or most material ending up in the resulting turbidity current. 相似文献
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Excellent deep ocean records have been obtained of two tsunamis recently generated in the Alaskan Bight on 30 November 1987 and 6 March 1988, providing the best available data set to date for comparison with tsunami generation/propagation models. Simulations have been performed with SWAN, a nonlinear shallow water numerical model, using source terms estimated by a seafloor deformation model based on the rectangular fault plane formalism. The tsunami waveform obtained from the model is quite sensitive to the specific source assumed. Significant differences were found between the computations and observations of the 30 November 1987 tsunami, suggesting inadequate knowledge of the source characteristics. Fair agreement was found between the data and the model for the first few waves of the 6 March 1988 tsunami. Model estimates of the seismic moment and total slip along the fault plane are also in fair agreement with those derived from the published Harvard centroid solution for the 6 March 1988 event, implying that the computed seafloor deformation does bear some similarity to the actual source. 相似文献
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煤及煤层顶底板的孔隙结构特征 总被引：2，自引：0，他引：2
使用９３１０型微孔结构分析仪,对煤和煤层顶、底板岩石的孔隙特征作了系统研究,取得下列结论：煤的孔隙发育主要受煤的变质程度、煤岩组分及成煤植物和后期构造破坏等因素的综合控制;碎屑岩的孔隙发育主要受岩石粒度和充填胶结程度控制;灰岩孔隙发育特征主要受溶蚀作用强度控制。 相似文献
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浅析新疆焉耆盆地土壤次生盐渍化治理途径 总被引：4，自引：0，他引：4
新疆焉耆盆地农田土壤次生盐渍化程度严重，分布面积大，灌溉用地表水量多，排碱渠密布，排碱渠大量高矿化度水排人博斯腾湖，使湖水水质受到影响，其生态环境极其脆弱。本文试图从土壤次生盐渍化的形成机制、成因分析，采用开采地下水、竖井排灌，置换地表水，结合调整农业产业结构等综合治理方法，从根本上解决盆地土壤次生盐渍化问题，以减少高矿化度水向博斯腾湖的排放，使盆地生态环境向良性方向发展。 相似文献
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科学与技术并进——近20年来海底峡谷浊流观测的成就和挑战 总被引：2，自引：1，他引：1
自1993年至今,美国地质调查局的科学家及其合作伙伴在美国西海岸的Monterey海底峡谷进行了针对现代浊流过程的一系列基础性研究,并成功地在世界上首次实地测量到高精度浊流流速及粒度参数.近20年来的数据和知识积累为解释海底峡谷内沉积物和其他颗粒物质输运的机理,以及浊流在维持深海峡谷中生机勃勃的生态系统所起的重要作用提供了直接依据.通过展示把海底观测应用于海洋沉积动力学研究过程中的成果、经验、教训,以及介绍目前还在讨论中的研究计划,以期达到以下宏观论点:在海洋科学里,只有科学与技术不脱节的科研团队才有希望获得成果和突破. 相似文献
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Air-flow geometry in air sparging of fine-grained sands 总被引：1，自引：0，他引：1
Laboratory visualization experiments in fine- to very fine-grained sands (grain diameter <0.21 mm) reveal a previously unrecognized
air-flow geometry. This air-flow geometry is termed "chamber flow" and is characterized by: (1) a significant horizontal component,
(2) pervasive air-flow coverage within a region demarcated by a distinct, irregular boundary, and (3) the presence of predominantly
vertical inlet and outlet channels. The attributes of chamber flow differ significantly from channelized flow and pervasive/bubbly
flow, which occur at larger grain sizes and have been described in the literature by several researchers. Previous research,
which indicates a dramatic increase in contaminant removal time in sediments <0.2 mm, indirectly corroborates the phenomena
observed in this study. The extent of sediment column affected by chamber flow of sparge air ranges from 4–54% on an area
basis, and is approximately 28% on a volume basis. These values indicate that chamber air flow has the potential to affect
a much larger percentage of the sediment column than either channelized or pervasive/bubbly flow. Because of the irregularity
of air-flow chambers, in terms of both form and frequency, a detailed knowledge of stratigraphy is important to maximize air-sparging
efficiency at sites where chamber flow is likely to occur.
Electronic Publication 相似文献