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91.
92.
地景模型的简化与快速绘制方法研究 总被引:2,自引:0,他引:2
在分析地景模型数据特点的基础上,提出了地景模型简化的判决准则,并根据该则提出了基于视点的区域数据抽取与简化方法以及基于法矢量的细节模型简化方法。实验结果表明,使用该方法数据压缩量大,绘制速度快,且逼真度无明显变化。 相似文献
93.
94.
赣西卡林型金矿找矿评价标志及找矿模式 总被引:1,自引:0,他引:1
从地球化学,地层岩性,构造,岩浆岩,金矿化及相关矿化,蚀变,找矿矿物学等方面阐明了赣西地区卡林型金矿的区域找矿评价标志及矿床评价标志,建立了赣西地区卡林型金矿“三个有利赋矿层位,三个有利赋矿岩性和三种有利元素组合”的找矿模式。 相似文献
95.
从新疆和硕县南山金矿床地质特征和地球化学特征的入手,分析其独特的控矿地质因素,提出了矿床的地质、地球化学找矿标志。 相似文献
96.
97.
胡聿贤 《地震工程与工程振动(英文版)》2003,2(1):35-38
Current design criteria and principles of earthquake engineering design are reviewed, including safety factors, probabilistic
approach, and two-level and multi-level functional design ideas. The modern multi-functional idea is discussed in greater
details. When designing a structure, its resistance to and the intensity of the earthquake action are considered. The consequence
of failure of the structure is considered only through a rough and empirical factor of importance, ranging usually from 1.0
to 1.5. This paper suggests a method of “consequence-based design,” which considers the consequences of malfunctioning instead
of simply an importance factor. The main argument for this method is that damage to a structure located in different types
of societies may have very different consequences, which are dependant on its value and usefulness to the society and the
seismicity in the region. 相似文献
98.
Based on the total phosphorous (TP) concentration in sediment core, the TP concentration in lake water quantitatively reconstructed from fossil diatoms and diatom-TP transfer function in the Longgan Lake during the last 200 years, the temperature and precipitation data from meteorological observation for the last 50 years, the temperatures and precipitation sequences of climate simulation for the last 200 years, as well as the amount of the agricultural phosphate fertilizer in Longgan area for nearly 50 years, the characteristic and the law of the nutrient status evolution were analyzed, and the influence of the climatic factor, the anthropologic factor and the aquatic biology factor on the nutrient status evolution and its mechanism were discussed for the Longgan Lake during the last 200 years. The results showed that, in the nearly 200 years, the TP concentration in the sediment core of the Longgan Lake gradually increased, its range of variation was situated between 330-580 mg/kg, the mean value was 388 mg/kg, a nearly 30-year vibration adjustment period existed at 1950 around. The TP concentration in lake water changed in a different way. Before 1950, it had a slow increasing tendency in fluctuated background, to 1950 around it reached up to the mean value (52.18μg/L), and vibrated and adjusted around the mean value, then it fast declined, its change range was situated between 37.75-62.33μg/L. The analyses indicated that, in the centennial time scale, the climate change was the main controlling factor, while in the decadal time scale in the recent 50 years, human activities were the leading factors for the nutrient status evolution of the Longgan Lake. 60% of the variability of the TP concentration in the sediments and 57% of that in lake water were due to human activities. The differentiation between phosphorus concentration in the sediment and in the lake water reflected the response processes and the adjustment abilities of the lake aquatic ecosystems to the lake nutrient level, implying the maintenance and the destruction of the balances between the algae and the aquatic plants, as well as the corresponding accumulating characteristics of the phosphorus. 相似文献
99.
陕西马元地区铅锌矿地质特征及找矿方向 总被引:7,自引:0,他引:7
陕西马元地区铅锌矿位于扬子地台北缘碑坝隆起东南缘一带。矿化带长大于60 km,宽10~200 m,可分为南、东、北三个铅锌矿化带,已圈出了40多条铅锌矿体。其中南矿化带长大于20 km,宽20~120 m,已圈出了40多条铅锌矿体;东矿化带长大于30 km,宽20~200 m,地表已发现7条铅锌矿体;北矿化带长大于10 km,宽10~100 m。矿体一般长100~2560 m,厚0.80~10.01 m,锌品位1.05%~10.82%,铅品位0.55%~7.54%。主矿体长2560 m,厚1.46~32.53 m,平均厚约7.60 m,最厚28.40 m,锌品位1.45%~11.42%,平均4.47%。矿化带主体由震旦系灯影组白云岩组成,产于灯影组的砾状白云质角砾岩带中。矿化主要受地层和构造的控制。经预测,陕西碑坝—马元、云河—庙坝、阳平关—宽川铺—阜川、司上—镇巴、镇坪及湖北竹溪、神农架、黄陵等地区有较好的找矿前景。 相似文献
100.
小波分析在重力界面反演中的应用 总被引:1,自引:0,他引:1
基于Parker-Oldenburg反演方法,分析了低通滤波器B(K)的不同阈值对位场分离的影响。分别采用小波变换和低通滤波对青藏高原地区布格重力异常进行了位场分解和莫霍面反演,并将反演结果与地震资料作比较。结果表明,在重力位场分解中小波多尺度分解可以代替低通滤波器B(K),避免了闻值的选取。 相似文献