基于GPS的高速公路车速全程监控方法研究

对高速公路车速进行有效监控与管理,是抑制违章超速行驶、减少高速公路交通事故的重要手段。现有的基于点速度和区间平均速度的高速公路车速监控方法,难以准确反应出车辆的实际行驶状态,实施效果有限,可靠性较差。文中提出基于GPS和地图匹配技术的高速公路车速全程监控和管理方法,建立相关算法的数学模型。经过理论分析和实例验证,车速监控与管理方法能实现高速公路车速的全程监控,极大地提高车速安全监控和管理的可靠性、准确性和有效性。     

智能CAD中图的一种表示方法

试图提出广义结点概念，并给出图的一种表示方法。该方法用邻接表法表示广义结点与邻近广义结点的关系，用向量表示法表示单一属性广义结点链。在实现方法上，不采用链接表结构，而用动态通用串结构很好地实现了图的运算操作。并举例说明在智能地ＣＡＤ中的运用。     

自然资源全要素自适应野外调查框架设计

针对自然资源全要素调查工作中分类标准不同、调查口径不同、调查方法不同,造成的各部门调查软件平台重复开发建设和调查数据结果地理信息特征表达不清晰等问题,本文结合自然资源全要素野外调查工作的实际需要,以山水林田湖草生命共同体为统一对象,构建了自然资源语义化特征模型,提出了表征不同自然资源类型的自适应野外调查方法,实现了灵活性高、性能优异的自然资源调查技术平台,形成了统一的自然资源全要素野外调查框架,可以有效提升多门类自然资源基础调查、专业调查、动态调查的能力与水平,为自然资源治理能力现代化提供了可靠技术保障。     

国产磁通门磁力仪稳定性分析

国产磁通门磁力仪(GM-3磁通门磁力仪)在全国各地磁台站推广应用,两年来,该仪器在武汉地震台工作比较稳定。本文对该仪器的基线值进行了多层线性回归分析。结果表明仪器性能比较稳定。     

Hydrothermal plume mapping as a prospecting tool for seafloor sulfide deposits: a case study at the Zouyu-1 and Zouyu-2 hydrothermal fields in the southern Mid-Atlantic Ridge

Seafloor hydrothermal polymetallic sulfide deposits are a new type of resource, with great potential economic value and good prospect development. This paper discusses turbidity, oxidation–reduction potential, and temperature anomalies of hydrothermal plumes from the Zouyu-1 and Zouyu-2 hydrothermal fields on the southern Mid-Atlantic Ridge. We use the known location of these vent fields and plume data collected in multiple years (2009, 2011, 2013) to demonstrate how real-time plume exploration can be used to locate active vent fields, and thus associated sulfide deposits. Turbidity anomalies can be detected 10 s of km from an active source, but the location precision is no better than a few kilometers because fine-grained particles are quasi-conservative over periods of many days. Temperature and oxidation–reduction potential anomalies provide location precision of a few hundred meters. Temperature anomalies are generally weak and difficult to reliably detect, except by chance encounters of a buoyant plume. Oxidation–reduction potential is highly sensitive (nmol concentrations of reduced hydrothermal chemicals) to discharges of all temperatures and responds immediately to a plume encounter. Real-time surveys using continuous tows of turbidity and oxidation–reduction potential sensors offer the most efficient and precise surface ship exploration presently possible.     

Characterization of rocking shallow foundations using centrifuge model tests

This paper presents new results of centrifuge model tests exploring the behavior of rocking shallow foundations embedded in dry sand, which provides a variety of factors of safety for vertical bearing. The results of slow (quasi‐static) cyclic tests of rocking shear walls and dynamic shaking tests of single‐column rocking bridge models are presented. The moment–rotation and settlement–rotation relationships of rocking footings are investigated. Concrete pads were placed in the ground soil to support some models with the objective of reducing the settlement induced by rocking. The behavior of rocking foundation was shown to be sensitive to the geometric factor of safety with respect to bearing failure, L_f/L_c, where L_f was the footing length, and the L_c was the critical soil‐footing contact length that would be required to support pure axial loading. Settlements were shown to be small if L_f/L_c was reasonably large. Placement of concrete pads under the edges of the footing was shown to be a promising approach to reduce settlements resulting from rocking, if settlements were deemed to be excessive and also had impacts on the energy dissipation and rocking moment capacity. A general discussion of the tradeoffs between energy dissipation and re‐centering of rocking foundations and other devices is included. Copyright © 2011 John Wiley & Sons, Ltd.     

Terrestrial photogrammetric techniques applied to the control of a parabolic dune in the Liencres dune system,Cantabria (Spain)

The spatial–temporal variations of a dune system can be determined by using diverse ‘geomatic’ methodologies: geodesy, global positioning system (GPS) and photogrammetry. In the case of the Liencres dune system, a study will be carried out using the ‘close‐range’ photogrammetry technique and the topography technique (total station and GPS). In order to determine the dynamic of the dune system it is necessary to repeat the process of study after a specific interval of time. For this reason, three dimensional data should be available in two different time periods, between which the displacement of the object of analysis (the front portion of the dune) will be significant enough to evaluate its magnitude. This work analyses the viability of photogrammetry for the determination of the spatial–temporal changes of a coastal parabolic dune. Two factors have been analysed: first, the comparison of the photogrammetric results with the results obtained from topographic methods (total station and GPS), and second, the quantification of the displacement of the dune system. The analysis of the correspondence between the movement of different parts of the dune and the influence of the intensity and direction of the prevailing wind in the area is also desired. The dune advanced 12·15 ± 0·06 m (an average of 8·5 m/yr), and the partial implications for the dynamic of human modified processes on the natural park have been established. Copyright © 2008 John Wiley & Sons, Ltd.     

A Statistical Study of Rapid Sunspot Structure Change Associated with Flares

We reported recently some rapid changes of sunspot structure in white-light(WL) associated with major flares.We extend the study to smaller events and present here results of a statistical study of this phenomenon.In total,we investigate 403 events from 1998 May 9 to 2004 July 17,including 40 X-class,174 M-class,and 189 C-class flares.By monitoring the structure of the flaring active regions using the WL observations from the Transition Region and Coronal Explorer(TRACE),we find that segments in the outer sunspot structure decayed rapidly right after many flares;and that,on the other hand,the central part of sunspots near the flare-associated magnetic neutral line became darkened.These rapid and permanent changes are evidenced in the time profiles of WL mean intensity and are not likely resulted from the flare emissions.Our study further shows that the outer sunspot structure decay as well as the central structure darkening are more likely to be detected in larger solar flares.For X-class flares,over 40% events show distinct sunspot structure change.For M-and C-class flares,this percentage drops to 17% and 10%,respectively.The results of this statistical study support our previously proposed reconnection picture,i.e.,the flare-related magnetic fields evolve from a highly inclined to a more vertical configuration.     

Hydrostratigraphic framework and hydrogeological behaviour of the Mancha Oriental System (SE Spain)

The Mancha Oriental System (MOS) has a surface area of 7,260 km², making it one of the largest carbonate aquifer systems in Spain. The system sustains about 1,000 km² of irrigated crops and supplies groundwater to 275,000 inhabitants. The economic transformation brought about by the development of extensive irrigated cropland has led to a water-balance disequilibrium of about 75 million m³/year. This input–output deficit has negative consequences in the quantity and quality of the available resources, in the river–aquifer relationship, and in the associated ecosystems as well. To understand the hydrogeological behaviour of the system, it is necessary to design a conceptual model. Further, the conceptualisation of a groundwater flow system is a requirement of the European Water Framework Directive for the characterisation of groundwater bodies. The robustness of the conceptual model depends heavily on the user capability of representing the real system. In this work, a multidisciplinary approach has been used to represent the three-dimensional geological framework and the groundwater flow conceptualisation of the MOS. Data management and three-dimensional visualisation have been carried out by means of geographical information system (GIS) tools and software for contouring and three-dimensional surface mapping.     

班怒带西段尕尔穷铜金矿两套侵入岩源区及其地质意义——来自Hf同位素特征的指示

尕尔穷铜金矿位于班公湖—怒江缝合带西段南缘的措勤—申扎火山岩浆弧内,为与侵入岩有关的矽卡岩型-破碎带型铜金(铁)矿床。在已有石英闪长岩LA-ICP-MS锆石U-Pb测年的基础上,进一步对其进行锆石Hf同位素研究,同时对最新勘查成果显示具有一定成矿潜力的花岗斑岩进行LA-ICP-MS锆石U-Pb定年和Hf同位素研究,确定了两套侵入岩的形成顺序;结合前人总结的岩石地球化学特征,利用Hf同位素对其岩浆源区进行示踪。结果显示:花岗斑岩锆石206Pb/238U年龄加权平均值为(83.2±0.7)Ma,较石英闪长岩晚4 Ma左右,其初始176Hf/177Hf值为0.282 235～0.283 073,εHf(t)值为-17.2～12.5;石英闪长岩锆石初始176Hf/177Hf值为0.282 800～0.283 015,εHf(t)值为3.5～10.5。结合二者地球化学特征显示:石英闪长岩和花岗斑岩可能是同一岩浆系统不同分异阶段的产物,前者主要起源于具有幔源印记的初生地壳,而花岗斑岩具有和石英闪长岩相似的岩浆源区,但明显混入上地壳基底物质;暗示晚白垩世班怒带西段南缘内随着南羌塘—三江复合板片与冈底斯—念青唐古拉板片之间的弧-陆碰撞,先成的具有幔源印记的初生地壳重熔形成岩浆,随着碰撞的继续和岩浆的上涌分异,部分上地壳受挤压或热效应进一步重熔并参与岩浆系统中,由早至晚形成了由幔源特征向幔-壳混合源特征源区逐渐转变的花岗岩演化系列。尕尔穷铜金矿是起源于具有幔源印记的初生地壳的花岗岩的成矿专属性表现。