基于Matlab GUI的全球重力固体潮可视化实现

阐明重力固体潮理论值计算原理,利用改进的计算新方法编写Matlab计算程序,采用Matlab中的GUI平台,对全球重力固体潮进行可视化实现,直观观察固体潮在地面的时空变化规律。通过输入时间和经纬度,确定采样间隔(秒采样、分钟采样、时采样),实现以下功能:(1)以图像和Excel形式,输出某一地区的重力固体潮理论值;(2)仿真未来24小时全球重力固体潮。     

A range-dependent echo-association algorithm and its application insplit-beam sonar tracking of migratory salmon in the Fraser Riverwatershed

Fish sonars have long been used to survey and monitor migratory salmon in rivers and at sea. However, research has been lacking in the development of algorithms to extract fish tracks from data collected in a riverine or oceanic environment. Current fish trackers, based on a pulse-to-pulse tracking method, only work well under ideal conditions when targets are well separated and the signal-to-noise ratio is high. Fisheries biologists often have to identify fish traces visually from raw echograms. This approach is both labor-intensive and time-consuming, limiting the usefulness of hydroacoustic techniques for fisheries management. This paper presents a fish-tracking algorithm which sorts randomly distributed echoes into coherent fish traces. Fish counts obtained with the algorithm compare well with visual counts at two quite different sites in the Fraser River watershed. The key features of the algorithm are: (1) the linking mechanisms among sequential fish echoes are range-dependent; (2) the growth echo for a developing track depends not only on its space-time relation with the previous track echo (the pulse-to-pulse statistics) but also on its relation to the entire track being constructed; (3) there are a total of only five echo-association criteria in the algorithm; (4) the simplicity of the algorithm structure provides a convenient platform for implementing specific and sophisticated tracking criteria to meet specific needs; and (5) the user can fully control the performance of the algorithm by choosing values for the 11 well-defined tracking parameters     

Changes in lead concentration in Antarctic penguin droppings during the past 3,000 years

Anthropogenic lead (Pb) has been found in Antarctic seawater, surface snow and ice-cores. Here, we analyzed a 3,000-year record of lead concentration in lake sediments affected by penguin droppings. We found that lead concentration in penguin droppings has significantly increased during the last 200 years, especially in the last 50 years, as compared to low and stable lead levels prior to the Industrial Revolution. This clearly indicates that global environmental pollution has influenced the Antarctic ecological system. Heavy metal (Pb) may find its way into the food web, bioaccumulate, and be passed along the chain to penguins.     

Evaporation of Accretion Disks around Black Holes: The Disk-Corona Transition and the Connection to the Advection-dominated Accretion Flow

We apply the disk-corona evaporation model (Meyer & Meyer-Hofmeister) originally derived for dwarf novae to black hole systems. This model describes the transition of a thin cool outer disk to a hot coronal flow. The mass accretion rate determines the location of this transition. For a number of well-studied black hole binaries, we take the mass flow rates derived from a fit of the advection-dominated accretion flow (ADAF) model to the observed spectra (for a review, see Narayan, Mahadevan, & Quataert) and determine where the transition of accretion via a cool disk to a coronal flow/ADAF would be located for these rates. We compare this with the observed location of the inner disk edge, as estimated from the maximum velocity of the Halpha emission line. We find that the transition caused by evaporation agrees with this determination in stellar disks. We also show that the ADAF and the "thin outer disk + corona" are compatible in terms of the physics in the transition region.     

吉林省对流性天气的分布特征及地形影响机制

通过对吉林省强对流天气和对流性天气活动与地形关系的分析，初步揭示出地形对两类对流天气的影响机制，其结果对进一步分析研究和准确预报强对流天气具有重要意义。     

湖南土地资源及其利用研究

本文论述湖南土地资源的主要特点，分析了土地利用现状及存在的主要问题，同时提出对土地资源的合理开发利用措施。     

长江上游泥石流较轻度危险区

区内共有２０个小区，面积３０．６３万ｋｍ＿２．本区地跨８省区．区内有１４个小区泥石流自然危险度级别为Ｃ级（面积１１．９１万ｋｍ￣２），６个小区泥石流自然危险度级别属Ｄ级（面积１８．７２万ｋｍ￣２）．本区有４座县城受泥石流威胁或危害，除此之外泥石流危害程度一般较轻．     

Geochemical patterns from local to global

The historical development of geochemical exploration is, in a sense, a process of progressive enlargement of areal coverage by exploration projects and progressive widening of sampling space. Along with this process, a hierarchy of geochemical patterns from small to large is gradually discovered and understood. In this paper, we try to summarize systematically the whole hierarchy of geochemical patterns from local, regional, provincial, megaprovincial to global, using examples obtained in China.Local anomalies (various types of dispersion halos, trains and fans) within areas not exceeding a few km², can be delineated when sampling is done with very close intervals in limited areas. Regional anomalies within areas of tens to hundreds km² and threshold values lower than local anomalies can be identified only when large areas of more than thousands of km² are mapped with wider space sampling. Geochemical provinces with areas of thousands or tens of thousands of km² can be discovered if even larger areas, of more than tens or hundreds of thousands of km², are covered with very low density sampling. More than millions of km² should be covered in order to discover geochemical megaprovinces somewhere in the world. Such megaprovinces are often associated with extraordinarily large mineral resources. If ultra-low density geochemical mapping can be carried out across national boundaries on a continental or global scale, we could find even broader geochemical patterns which will reflect the global tectonic features.The classification of geochemical patterns according to their sizes is necessary because it will be extremely useful in planning sampling layout in order to hit targets of certain size ranges. This in turn is arranged in different geochemical projects for achieving specific aims.