数字卫星云图估算面雨量的应用试验

使用云分类降水率估计的方法，有静止气象卫星数字云图进行面雨量估算。对１９９３年８月４日华北南部一次降水过程的实测雨量与估算结果的对比分析表明，这种估算方法对雨区的差别有相当高的精度，对雨量的估计有一定的参考价值。     

Climatology of meteorological “bombs” in the New Zealand region

Summary The purpose of this paper is to present a recently developed climatology of explosively developing south eastern Tasman Sea extra-tropical cyclones, or meteorological “bombs”, using a latitude dependent definition for meteorological bombs based on that of Simmonds and Keay (2000a, b), and Lim and Simmonds (2002). These highly transient systems, which have a damaging impact upon New Zealand, are frequently accompanied by destructive winds, flood rains, and coastal storm surges. Two cases are selected from the climatology and briefly described here. The first case study is the major flood and storm force wind event of June 20 to 21, 2002 that affected the Coromandel Peninsula region of the North Island of New Zealand. The second case was a “supercyclone” bomb that developed well to the southwest of New Zealand region during May 29 to 31, 2004, but which could easily have formed in the New Zealand region with catastrophic consequences. It was well-captured by the new high resolution Quikscat scatterometer instrument.This study extends the work of two of the authors (Buckley and Leslie, 2004; Buckley and Leslie, 2000; Qi and Leslie, 2000), on southern hemisphere meteorological bombs, to yet another geographical location. Here, we relied heavily on surface observations, scatterometer and other satellite-derived data, and weather radar imagery in developing the climatology.     

FD-125测氡仪观测中值得注意的几个问题

论述了FD-125测氡仪在水氡观测中值得注意的几个问题：①仪器的供电系统中不应有线路接触不良；②仪器接地线应避免接触不良；③其他用电器内部线路也不应有接触不良；④引起电场和磁场变化的大功率用电设备不应在测量时间内使用；⑤供电电路中电压尽可能避免大幅度波动等。上述因素对氡测值都有影响，影响幅度可达10％以上。     

金川超镁铁质岩元素及稀有气体同位素地球化学特征

金川超镁铁质岩是金川铜镍硫化物矿床的赋存岩体．采自金川镍矿Ⅰ矿区露天矿第2期侵入岩体的样品其岩石类型主要为含二辉橄榄岩和二辉橄榄岩，见镍黄铁矿、磁黄铁矿、黄铁矿呈成条带状出现，表明其形成时低氧逸度的成岩环境。运用ICP—MS等离子质谱仪和MM5400稀有气体质谱仪分别对全岩样品的稀土元素、微量元素和包体稀有气体同位素进行测定后得到一些认识：金川超镁铁质岩的微量元素丰度与球粒陨石相比，变化曲线基本呈水平分布，但是地壳中高度亏损Cr，Ni元素含量较高，主要富集于超基性的辉石和橄榄石中，说明其成因类型具有明显的幔源特征。岩石中稀土元素总量较高，为轻稀土富集型．重稀土亏损。其中由深至浅稀土元素对La／Yb，Ce／Yb，La／Sm，(La／Sm)N的比值均基本呈现增大趋势．说明其中稀土元素分馏程度呈增大趋势，轻稀土的分馏尤为明显。超镁铁质岩的^3He／^4He值分布于0．847Ra～1．625Ra之间，虽远低于上地幔的^3He／^4He值．但仍存在地幔初始氦的踪迹。研究结果表明，该岩体在侵入过程中发生了明显的分异作用，并与地壳发生了的混染作用和热液交代作用．进一步证明了该岩体为上地幔局部熔融的超基性岩浆上侵形成的。     

广东大亚湾石珊瑚群落的分布及动态变化

2006年6月对位于南海北部亚热带的大亚湾和大鹏湾石珊瑚群落的分布、种类和覆盖率进行了调查,结果显示大亚湾共有石珊瑚24种,以秘密角蜂巢珊瑚(Favites abdita)为优势种,总覆盖率为20%,大鹏湾有石珊瑚21种,以精巧扁脑珊瑚(Platygyra daedalea)为优势种,总覆盖率为7.9%。大亚湾石珊瑚群落健康状况良好,但生长稀疏,群落密度低,空间结构简单,生长带窄;与1964年、1983年、1984年和1991年的调查结果相比,覆盖率从76.6%下降到20%,优势种从枝状的霜鹿角珊瑚(Acropora Pruinosa)转变成块状或皮壳状的秘密角蜂巢珊瑚,群落生态退化严重,主要原因可能是人为破坏活动对珊瑚本身以及生长环境造成的压力所致,包括过度捕捞、盗采珊瑚、沿岸施工和水体污染等,建议采取相应的保护措施。     

小灌区农田土壤水分析

对山西省小灌区农田土壤水分在时空分布及其影响因素进行了分析.结果表明:大气降水、农田灌溉、作物蒸腾和田间土壤蒸发是影响土壤水分变化的主要因素.农田土壤水分分布随着作物的种类而变化.     

沉积物粒度对水合物形成的制约：来自IODP 311航次证据

对取自IODP 311航次（东北太平洋Cascadia大陆边缘）所有5个站位、采样间距约为1.5 m的614件沉积物样品，利用Beckman Coulter LS 230激光粒度仪进行了沉积物粒度分析，获得了沉积物粒度随深度变化特征，进而与水合物层位的替代指标进行了位置对比，这些指标包括特殊沉积构造（soupy和mousse like构造）、测井数据（LWD）推算出来的水合物饱和度（Sh）、岩芯红外图像和实际钻取的含水合物沉积物等。发现沉积物粒度分别为31~63 μm和63~125 μm的2组较粗粒径的沉积物数量变化增多的位置与水合物出现层位之间存在较好的位置对应关系。如在U1326站位海底以下5~8 m、21~26 m、50~123 m、132~140 m、167~180 m、195~206 m、220~240 m深度位置出现了沉积物粒度明显偏向粗粒的趋势，而这些位置正好对应于大多数特殊沉积构造出现的深度，也对应于水合物饱和度（Sh）值相对较高的深度，并与一些实际钻取的赋含水合物的浊积沙层观察结果一致。因此，初步研究后认为，沉积物粒度在水合物形成过程中扮演了重要角色，天然气水合物可能偏向形成于粒度大于31 μm的粗粒沉积物中。       

降雨对斜坡失稳的影响作用探讨

降雨入渗是致使斜坡岩土体稳定性下降并最终导致崩塌、滑坡等地质灾害发生最为常见的环境因素.通过分析,得出降雨有增大斜坡下滑力及致使抗剪强度降低的作用,并通过对比某斜坡在自然状态及降雨状态下的稳定性及剩余下滑力,证明了降雨对斜坡失稳具有较大影响.     

A new criterion for strength of frozen sand under quick triaxial compression considering effect of confining pressure

The strength of frozen soils has been one of the most extensively studied aspects in frozen soil mechanics. When carrying out deep excavations using freezing methods, high stress states are often encountered. Therefore, the strength of frozen soils under high confining pressures is of major concern. This paper first reviews the present failure criteria for frozen soils, especially with regard to the effect of confining pressure on the strength. It is suggested that the strength consists of two components, cohesion and friction, and can be expressed by the Mohr–Coulomb criterion and in the framework of the Drucker–Prager criterion. However, these two components are both dependent on the stress state. Duncan’s equation for the friction angle is extended to frozen soils. A frozen Lanzhou fine sand is taken as study subject. The frozen sand is compressed at a high strain rate under three different temperatures and under a wide range of confining pressure. Experimental results have confirmed the generally recognized principle that the strength increases with the confining pressure up to certain value. Thereafter, it decreases with continued increase in confining pressure. Experimental data from our own tests and literature are fitted to the new criterion, which shows its validity.     

地面起伏对成像及雷达景象匹配的影响

景象匹配是飞行器导航与定位的一种重要手段,其中的雷达图像匹配由于具有全天候的特征而受到人们的重视.在分析了实时雷达图像成像方式的基础上,具体分析了地面高程起伏对雷达图像构像的影响,并进一步推导出在实时雷达图像上,图像像点位移与地面高程起伏的具体关系;以及为了保证一定的匹配定位精度,对于实飞地区地面起伏的定量要求.同时还对导航定位匹配所用的参考基准图受地面高程起伏的影响情况进行了定量的分析,并对理论情况和实际图像进行了计算分析与比较,最后得出在给定匹配精度的情况下,生成参考图时对成像区域内点之间的高差限制要求.