贵州省兴仁县近50年气候特征及其变迁分析

局地气候资料的整理分析,是对更大范围内某一地区的气候研究提供参考的依据之一。贵州省兴仁是国家基准气候站,观测资料较长,对贵州西南片区有较好的代表性。通过对兴仁50年完整的气象资料整理分析,得出该地温度、降水、风、相对湿度、云量、雾日、光照等气象要素的基本特征,并以此特征作出该地的气候类型评定;同时根据该地近50年冷暖趋势、干湿趋势的变化,分析总结出其近代的气候变迁。     

珠三角地区地震前兆场特征及近期地震危险性分析

应用时空域层次分析新思路及我国地震科技攻关成果对珠江三角洲地区的地震前兆资料进行了数据处理和综合分析,对该区的地震前兆场特征作了较全面系统的研究,并对目前存在的区域前兆异常场进行特征分析。研究认为,区内现有的前兆监测方法在中强地震发生前呈现出与正常动态变化相异的中期或中短期前兆异常反映,并具有相对丛集的总体特征。前兆异常场由东莞虎门重力、广州水化学等构成。最后对珠江三角洲地区近期的地震危险性进行了     

Flow of groundwater with variable density and viscosity, Atikokan Research Area, Canada

 Flow of groundwater with variable density and viscosity was simulated at the Atikokan Research Area (ARA) in northwestern Ontario, Canada. An empirical viscosity–concentration equation was modified to include total-dissolved-solids (TDS) data from the ARA. The resulting equation was used successfully to estimate reasonably accurate viscosity values over the expected range of temperature and concentration, in comparison with experimental values derived for sodium chloride solutions. A three-dimensional finite-element code, MOTIF, developed by Atomic Energy of Canada Limited, was used in the simulations. The inclusion of the effects of depth-increasing temperature and TDS-dependent fluid-density distribution, while maintaining only a temperature-dependent viscosity relationship in a simulation, resulted in a more penetrative flow against expected buoyancy effects (i.e., the physics of the system was not honored). Accounting for concentration in the viscosity equation caused water to be less penetrative and more in accordance with the expected physics of the system. A conclusion is that fluid concentration should be considered simultaneously in calculating the density and viscosity of a fluid during modeling of variable-density flow in areas underlain by fluids with high TDS. Results of simulations suggest that both flow directions and magnitudes should be employed simultaneously during the calibration of a model. Large-scale groundwater movement in the ARA may be analyzed with carefully selected vertical no-flow boundaries. By incorporating the geothermal temperature gradient, groundwater recharge increases by 12%; thus, this gradient plays a significant role in groundwater flow at the ARA. Variability in the fluid concentration at the ARA neither decreases nor increases recharge into the groundwater system. The hypothesis that an isolated continuous regional flow system may exist at depth in the ARA is not supported by these simulations. Received, September 1996 Revised, September 1997, February 1998 Accepted, February 1998     

利用空间测地技术结果估计地球平均下地幔粘性(英)

基于IEC－4G冰期后地壳反弹模型,和地球上Laurentia,Fennoscandia,Antarctica,andGreenland四大冰盖最近21000年以来的冰融参数,计算了对地球最大主转动惯量的影响△I33,并进而由现代空间测地技术观测资料分析得到的地球自转非潮汐加速项为约束,估计了地球平均下地幔（670km以下）粘性vLM为（0．9～2．5）·1022Pas,这个结果表明了vLM应具有1022Pas量级．     

对流层高层偏北气流在梅雨暴雨中的作用

文中对江淮梅雨暴雨过程中的高低空流场特征及物理过程进行分析．结果表明：对流层上部青藏高原东侧常有高空偏北大风轴汇入南亚东风急流中．在这支强北风轴北端发现高空辐散和辐散的增长．亦即有利于低层辐合上升的持续、发展和加强;表明了低层西南急流与高空青藏高压东侧的偏北强风轴之间的次级环流圈,有利于梅雨暴雨的持续．     

强震孕育与断层形变异常形态及时空分布特征

分析了华北北部20世纪70年代初以来的断层形变资料。结果表明：震前断层活动存在明显的阶段性特征；短临阶段断层形变异常主要形态有两种：一种是在α、β相后的γ相短临异常，这种异常一般在近源区出现；另一种是较大幅度的突跳型短临异常，这种异常一般在远源区出现，这些都是断层形变前兆由中期过渡到短期的明显标志；断层形变短临异常有从外围向震中迁移的特征；唐山地震前出现γ相短临异常的比例高于大同和张北地震，主要表现为在中期趋势积累背景上的反向；3次强震前α、β、γ相异常场地的分布具构造控制特征；强震前场地断层异常活动存在象限性分布特征，且与震源机制解的结果基本一致。     

织金白岩村大旗山崩塌危岩带发育特征及稳定性评价

通过对织金县城关镇白岩村危岩(崩塌带)调查,结合危岩体发育特征及周边地质环境状况,对危岩体稳定性进行定性评价和定量评价,并提出防治措施。     

黔北务正道铝土矿矿床特征及成矿模式——以务川大竹园铝土矿床为例

本文以黔北务川大竹园铝土矿床为例,对其矿体厚度、矿石品位沿走向和倾向变化特征进行分析,对矿石质量、矿石矿物、结构构造及矿石自然类型和工业类型进行了阐述。通过大量勘探成果资料分析认为,大竹园铝土矿床铝土矿的形成,为一个完整的＂母岩—风化—再沉积—成矿—改造—成熟—保存＂模式。