基于历史相似天气评估人工增雨效果

文章利用辽宁省1981～1990年10年无人工增雨作业的NCEP 500hPa高度场资料以及1996年、1997年有增雨作业的500hPa资料，对10年间无增雨日及两年中增雨日要素场采用“切比雪夫一傅立叶混合多项式”展开，以寻求两个要素场的最小相关值，藉此给出两年中不同增雨天气型的个例分析及23架次日增雨效果百分率。分析结果表明，在两个要素场达到最小相关值时，一方面两个要素场形势非常相似，另一方面在增雨日播撒区的降水量，大多明显地大于该区历史上非增雨日的降雨量，增雨基本上具有正效果；然而降水一般是由多因素相互作用产生的结果，在统计时也可能出现增雨的负效果或无效果，即“多异性”；但就总体而言，该方法有效地实现了一次增雨效果的评估。     

用地理因子模拟年度极端最低气温模式的探讨

利用福建省66个台站所处的纬度、海拔高度、离海距和观测站与周围的相对高度差等地理因子建立推算年度极端最低气温平均值的模式。     

A Concentration pdf for the Relative Dispersion of a Contaminant Plume in the Atmosphere

Observations of the dispersion of a contaminant plume in theatmospheric boundary layer, obtained using a Lidar, are analysedin a coordinate frame relative to the instantaneous centre of massof the plume. To improve the estimates of relative dispersionstatistics, maximum entropy inversion is used to remove noise fromthe Lidar concentration profiles before carrying out the analysis.A parametric form is proposed for the probability density function(pdf) of concentration, consisting of a mixture of a betadistribution and of a generalised Pareto distribution (GPD). Thispdf allows for the possibility of a unimodal or bimodaldistribution, and is shown to give a satisfactory fit toobservations from a range of positions relative to the source. Thevariation of the fitted parameters with crossplume location isanalysed, and the maximum possible concentration is found todecrease away from the plume centre.     

Structure-configurational entropy and its effect on the thermodynamic stability of uranyl phases: With special application for geological disposal of nuclear waste

Uranyl phases are found as the alteration products of uraninite under oxidizing condi- tions[1—3]. They are also expected to be the dominant alteration products of spent UO2 fuel in an oxidizing environment, such as at nuclear waste repositories[4—8]. …     

基于信息熵的离散空间场相关指数计算方法

为了定量测算面状分布的地理要素之间的相关性，基于信息熵理论和性质，给出了一个离散空间场相关指数，并论述了该指数的计算方法和特点。以MapInfo为平台，采用MapBasic编程，对一组分类图层之间的相关指数进行了计算。结果表明，该方法理论上严密，实用价值较大。     

拱形洞室围岩内岩爆的计算机模拟与控制方法

借用GDA软件来模拟开挖周边的应力重分布，在此基础上，重点分析了拱形洞室的拱顶、拱肩、两侧及底角的应力分布与岩爆的关系。并提出如何依据dσ3/（σ1-σ3）大小与正负来分析和估计岩爆位置，因为应力差σ1-σ3可表征岩石的变形与静态破坏，而最小主应力增量dσ3的大不可表征抵抗这种变形与破坏的能力。结果是拱肩与底角会出现岩爆。分析结果得到了加拿大某矿山的岩爆发生位置实际资料所验证。最后，提出了如何利用预裂爆破方法使岩爆从拱肩迁移到洞室底角。     

短期气候数值预报中的集合个数问题

利用中国科学院大气物理研究所IAP L2 AGCM1.1模式18年(1980～1997年,每年包含28个积分)的集合后报试验结果,讨论了数值预测中的最小集合个数问题.研究表明预测结果达到稳定所需的最小集合数随区域和年份而变化,对于我国汛期降水跨季度预测,最小集合数在全国范围为19～20个,对于东南区域为10个左右,东北、华北地区不应少于20个.当出现多平衡态时,最小集合数增大,这时应对各平衡态分别进行集合.研究结果同时还显示,对于有预报能力的地区,集合方法可以提高预测技巧及其可信度,而在负技巧区域,集台反使得预测效果更差,因而有必要进行系统性订正.     

光谱影像的灰度矢量相关特征与边缘特征提取

提出了多光谱图像像元特征矢量之间的极小互相关系数，极大互相关系数及互相关差值和相关密度的概念，在对模拟图像进行矢量相关分析及其对边缘提取的有效性分析基础上，提出对多光谱图像采取像元特征矢量相关分析并提取边缘信息的方法，对TM图像进行试验分析的结果说明了此方法的有效性。     

Geochemistry of Peruvian near-surface sediments

Sixteen short sediment cores were recovered from the upper edge (UEO), within (WO) and below (BO) the oxygen minimum zone (OMZ) off Peru during cruise 147 of R/V Sonne. Solids were analyzed for major/trace elements, total organic carbon, total inorganic carbon, total sulfur, the stable sulfur isotope composition (δ³⁴S) of pyrite, and sulfate reduction rates (SRR). Pore waters were analyzed for dissolved sulfate/sulfide and δ³⁴S of sulfate. In all cores highest SRR were observed in the top 5 cm where pore water sulfate concentrations varied little due to resupply of sulfate by sulfide oxidation and/or diffusion of sulfate from bottom water. δ³⁴S of dissolved sulfate showed only minor downcore increases. Strong ³²S enrichments in sedimentary pyrite (to −48‰ vs. V-CDT) are due to processes in the oxidative part of the sulfur cycle in addition to sulfate reduction. Manganese and Co are significantly depleted in Peruvian upwelling sediments most likely due to mobilization from particles settling through the OMZ, whereas release of both elements from reducing sediments only seems to occur in near-coastal sites. Cadmium, Mo and Re are exceptionally enriched in WO sediments (<600 m water depth). High Re and moderate Cd and Mo enrichments are seen in BO sediments (>600 m water depth). Re/Mo ratios indicate anoxic and suboxic conditions for WO and BO sediments, respectively. Cadmium and Mo downcore profiles suggest considerable contribution to UEO/WO sediments by a biodetrital phase, whereas Re presumably accumulates via diffusion across the sediment-water interface to precipitation depth. Uranium is distinctly enriched in WO sediments (due to sulfidic conditions) and in some BO sediments (due to phosphorites). Silver transfer to suboxic BO sediments is likely governed by diatomaceous matter input, whereas in anoxic WO sediments Ag is presumably trapped due to sulfide precipitation. Cadmium, Cu, Zn, Ni, Cr, Ag, and T1 predominantly accumulate via biogenic pre-concentration in plankton remains. Rhenium, Sb, As, V, U and Mo are enriched in accordance with seawater TE availability. Lead and Bi enrichment in UEO surface sediments is likely contributed by anthropogenic activity (mining). Accumulation rates of TOC, Cd, Mo, U, and V from Peruvian and Namibian sediments exceed those from the Oman Margin and Gulf of California due to enhanced preservation off Peru and Namibia.     

两步法反褶积在复杂地表地区的应用

在复杂地表条件的地方进行地震勘探时，因激发震源、检波器以及表层岩性不同会引起较大的子波差异，反射资料的品质较低。用两步法反褶积对炮点、检波点进行一致性处理，以消除炮点、检波点的差异。对一些实际地震资料进行了试处理，取得了较好的效果。